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  1. Investigating antimicrobial activity in Rheinheimera sp. due to hydrogen peroxide generated by l-lysine oxidase activity.

    PubMed

    Chen, Wen Ming; Lin, Chang Yi; Sheu, Shih Yi

    2010-05-05

    A greenish yellow pigmented bacterial strain, designated GR5, was recently isolated from a freshwater culture pond for a soft-shell turtle. Phylogenetic analyses based on 16S rRNA gene sequences indicate that strain GR5 belongs to the genus Rheinheimera and its only closest neighbor is the type strain of Rheinheimera texasensis (98.2%). Based on the antibiogram assay, strain GR5 possesses a broad spectrum of antimicrobial activity including Gram-positive and Gram-negative bacteria, yeast, algae, and strain GR5 itself. Strain GR5 can synthesize a macromolecule with antimicrobial activity due to the generation of hydrogen peroxide and this antimicrobial effect can be inhibited by catalase. This antimicrobial activity is active only in complex culture media or chemically defined culture media containing l-lysine. This antimicrobial macromolecule in strain GR5 is shown to be a monomeric protein with a molecular mass of 71kDa and isoelectric point of approximately 3.68. Liquid chromatography-tandem mass spectrometry analyses reveal close similarity of a 19-amino acid fragment derived from this protein to the antibacterial protein, AlpP from the marine bacterium Pseudoalteromonas tunicata D2, and to the antibacterial protein, marinocine, from the marine bacterium Marinomonas mediterranea. This study explores the nature of antimicrobial macromolecule such as l-lysine oxidase. This is the first report on a freshwater bacterium producing antimicrobial activity by generating hydrogen peroxide through its enzymatic activity of l-lysine oxidase.

  2. Solar irradiance variations due to active regions

    SciTech Connect

    Oster, L.; Schatten, K.H.; Sofia, S.

    1982-05-15

    We have been able to reproduce the variations of the solar irradiance observed by ACRIM to an accuracy of better than +- 0.4 W m/sup -2/, assuming that during the 6 month observation period in 1980 the solar luminosity was constant. The improvement over previous attempts is primarily due to the inclusion of faculae. The reproduction scheme uses simple geometrical data on spot and facula areas, and conventional parameters for the respective fluxes and angular dependencies. The quality of reproduction is not very sensitive to most of the details of these parameters; nevertheless, there conventional parameters cannot be very different from their actual values in the solar atmosphere. It is interesting that the time average of the integrated excess emission (over directions) of the faculae cancels out the integrated deficit produced by the spots, within an accuracy of about 10%. If this behavior were maintained over longer periods of time, say, on the order of an activity cycle, active regions could be viewed as a kind of lighthouse where the energy deficit near the normal direction, associated with the spots, is primarily reemitted close to the tangential directions by the faculae. The currently available data suggest that energy ''storage'' associated with the redirection of flux near active regions on the Sun is comparable to the lifetime of the faculae.

  3. Ionospheric Response Due to Seismic Activity

    NASA Astrophysics Data System (ADS)

    Sharma, Dinesh Kumar

    2016-07-01

    Signatures of the seismic activity in the ionospheric F2 region have been studied by analyzing the measurement of electron and ion temperatures during the occurrence of earthquake. The ionospheric electron and ion temperatures data recorded by the RPA payload aboard the Indian SROSS-C2 satellite during the period from January 1995 to December 2000 were used for the altitude range 430-630 km over Indian region. The normal day's electron and ion temperatures have been compared to the temperatures recorded during the seismic activity. The details of seismic events were obtained from USGS earthquake data information website. It has been found that the average electron temperature is enhanced during the occurrence of earthquakes by 1.2 to 1.5 times and this enhancement was for ion temperature ranging from 1.1to 1.3 times over the normal day's average temperatures. The above careful quantitative analysis of ionospheric electron and ion temperatures data shows the consistent enhancement in the ionospheric electron and ion temperatures. It is expected that the seismogenic vertical electrical field propagates up to the ionospheric heights and induces Joule heating that may cause the enhancement in ionospheric temperatures.

  4. Investigation of differential surface removal due to electropolishing at JLab

    SciTech Connect

    Marhauser, Frank; Folkie, James; Reece, Charles

    2015-09-01

    Surface chemistry carried out for Superconducting Radio Frequency (SRF) cavities such as Buffered Chemical Polishing (BCP) and Electropolishing (EP) aims to uniformly remove the internal surface of a cavity along the entire structure and within each cell from equator to iris in order to obtain an equally etched surface. A uniform removal, however, is not readily achievable due to the complex fluid flow and varying temperatures of the acid mixture, which can lead to differential etching. This needs to be considered when envisaging a certain surface damage removal throughout the interior. The process-specific differential etching influences the target frequency set at the manufacturing stage as well as the field flatness and length of the as-built cavity. We report on analyses of JLab's present EP system using experimental data for six nine-cell cavities that have been processed recently in the frame of the LCLS-II high-Q development plan. In conjunction with numerical simulations, the differential etching and the impact on field flatness is assessed.

  5. Numerical Investigation of Microgravity Tank Pressure Rise Due to Boiling

    NASA Technical Reports Server (NTRS)

    Hylton, Sonya; Ibrahim, Mounir; Kartuzova, Olga; Kassemi, Mohammad

    2015-01-01

    The ability to control self-pressurization in cryogenic storage tanks is essential for NASAs long-term space exploration missions. Predictions of the tank pressure rise in Space are needed in order to inform the microgravity design and optimization process. Due to the fact that natural convection is very weak in microgravity, heat leaks into the tank can create superheated regions in the liquid. The superheated regions can instigate microgravity boiling, giving rise to pressure spikes during self-pressurization. In this work, a CFD model is developed to predict the magnitude and duration of the microgravity pressure spikes. The model uses the Schrage equation to calculate the mass transfer, with a different accommodation coefficient for evaporation at the interface, condensation at the interface, and boiling in the bulk liquid. The implicit VOF model was used to account for the moving interface, with bounded second order time discretization. Validation of the models predictions was carried out using microgravity data from the Tank Pressure Control Experiment, which flew aboard the Space Shuttle Mission STS-52. Although this experiment was meant to study pressurization and pressure control, it underwent boiling during several tests. The pressure rise predicted by the CFD model compared well with the experimental data. The ZBOT microgravity experiment is scheduled to fly on February 2016 aboard the ISS. The CFD model was also used to perform simulations for setting parametric limits for the Zero-Boil-Off Tank (ZBOT) Experiments Test Matrix in an attempt to avoid boiling in the majority of the test runs that are aimed to study pressure increase rates during self-pressurization. *Supported in part by NASA ISS Physical Sciences Research Program, NASA HQ, USA

  6. Investigation of the Precipitates on the Concrete Surface due to Sulphate Exposure

    NASA Astrophysics Data System (ADS)

    Kovalčíková, Martina; Eštoková, Adriana; Oravec, Jozef; Luptáková, Alena

    2016-12-01

    The aim of this study is to investigate the durability of cement-based materials subjected to the effects of sulphuric acid in terms of surface deterioration. Damaged concrete surfaces and the samples' mass changes were studied during 270-day simulation of both chemical and biological attacks. Chemical corrosion was simulated by sulphuric acid with pH of 3.0 and 4.0, respectively, while biological corrosion was simulated by activity of bacteria Acidithiobacillus thiooxidans. XRD and SEM analyses confirmed a massive sulphate precipitate formation on the concrete surface due to chemical and biological sulphate corrosion.

  7. Grip force and muscle activity differences due to glove type.

    PubMed

    Kovacs, Kimberly; Splittstoesser, Riley; Maronitis, Anthony; Marras, William S

    2002-01-01

    The purpose of this study was to investigate the effects of different types and sizes of gloves on external grip force and muscle activity. Twenty-one male and seven female volunteers served as subjects. Each subject performed two maximum voluntary grip contractions while wearing each of the 10 glove types. Results indicated significant differences in the effects of different glove types on the peak force, ratio of peak force to normalized flexor muscle EMG activity, and the ratio of peak force to coactivity.

  8. Major geomagnetic storm due to solar activity (2006-2013).

    NASA Astrophysics Data System (ADS)

    Tiwari, Bhupendra Kumar

    Major geomagnetic storm due to solar activity (2006-2013). Bhupendra Kumar Tiwari Department of Physics, A.P.S.University, Rewa(M.P.) Email: - btiwtari70@yahoo.com mobile 09424981974 Abstract- The geospace environment is dominated by disturbances created by the sun, it is observed that coronal mass ejection (CME) and solar flare events are the causal link to solar activity that produces geomagnetic storm (GMS).CMEs are large scale magneto-plasma structures that erupt from the sun and propagate through the interplanetary medium with speeds ranging from only a few km/s to as large as 4000 km/s. When the interplanetary magnetic field associated with CMEs impinges upon the earth’s magnetosphere and reconnect occur geomagnetic storm. Based on the observation from SOHO/LASCO spacecraft for solar activity and WDC for geomagnetism Kyoto for geomagnetic storm events are characterized by the disturbance storm time (Dst) index during the period 2006-2013. We consider here only intense geomagnetic storm Dst <-100nT, are 12 during 2006-2013.Geomagnetic storm with maximum Dst< -155nT occurred on Dec15, 2006 associated with halo CME with Kp-index 8+ and also verify that halo CME is the main cause to produce large geomagnetic storms.

  9. [Investigation of uterine scraping after non-progressive pregnancy due to HLA compatibility in married couples].

    PubMed

    Milovanov, A P; Poliakova, A A; Volkova, L V

    2011-01-01

    Non-progressive pregnancy in the first trimester is one of the common and little studied causes of early habitual miscarriage. Pathohistological and immunohistochemical investigations of uterine scrapings were first carried out during laboratorily verified observations of HLA compatibility of two (12 patients) or more (12 patients) similar alleles. Stepwise degradation of decidual cells in the uteroplacental area and parietal endometrium was revealed as their pathomorphological equivalents due to the activation of local large granular lymphocytes and macrophages. These cells are characterized by a strong release of proteolytic enzymes and by cytolysis of surrounding decidual cells. Moreover, there was superficial cytotrophoblastic invasion, atrophy, and numerous villous epithelial defects with villous cytotrophoblast reduction. These pathological markers in the uterine scrapings are proposed to use for a further goal-oriented study of a married couple-HLA system.

  10. Do Young and Old Preschoolers Exhibit Response Bias Due to Different Mechanisms? Investigating Children's Response Time

    ERIC Educational Resources Information Center

    Okanda, Mako; Itakura, Shoji

    2011-01-01

    Previous studies have suggested that younger preschoolers exhibit a yes bias due to underdeveloped cognitive abilities, whereas older preschoolers exhibit a response bias due to other factors. To test this hypothesis, we investigated the response latency to yes-no questions pertaining to familiar and unfamiliar objects in 3- to 6-year-olds. The…

  11. 40 CFR 280.51 - Investigation due to off-site impacts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 27 2011-07-01 2011-07-01 false Investigation due to off-site impacts... to off-site impacts. When required by the implementing agency, owners and operators of UST systems must follow the procedures in § 280.52 to determine if the UST system is the source of off-site...

  12. 40 CFR 280.51 - Investigation due to off-site impacts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Investigation due to off-site impacts... to off-site impacts. When required by the implementing agency, owners and operators of UST systems must follow the procedures in § 280.52 to determine if the UST system is the source of off-site...

  13. Changes in osteoblastic activity due to simulated weightless conditions

    NASA Technical Reports Server (NTRS)

    Doty, S. B.; Morey-Holton, E. R.

    1982-01-01

    Using histochemistry and electron microscopy, the reduced bone formation which occurs in the hypokinetic, orthostatically treated adult rat has been studied. The two major changes noted occurred in the osteoblast population, indicated by a reduced alkaline phosphatase activity and reduced numbers of gap junctions between cells. These results were most noticeable in the periosteum and endosteum of the long bones. Changes in osteoblasts lining the surface of trabecular bone were not as evident. These results indicate that the cells lining the surfaces of weight bearing bones are most affected by hypokinesia and this reduction in cellular activity may be a mechanically induced effect.

  14. Effects of activity interference on annoyance due to aircraft noise

    NASA Technical Reports Server (NTRS)

    Willshire, K. F.; Powell, C. A.

    1981-01-01

    The effects of aircraft flyover noise on annoyance were compared for face to face conversation, reverie, and television viewing. Eighteen 5 minute sessions, each composed of three flyovers, were presented on each of 2 days to subjects in a simulated living room. Twelve pairs of females and 12 pairs of males were tested, once before and once after work. Flyovers varied in peak noise level from 53 to 83 dB, A weighted. On each day, subjects engaged in 18 sessions, six of conversation, six of television viewing, and six of reverie. The subjects completed subjective ratings of annoyance and acceptability following every session. Annoyance and unacceptability rating scores were significantly higher for the activity of television viewing compared to conversation or reverie. There was no difference between judgments during the latter two activities. No differences were found in the judgments when compared on the basis of "fatigue" (before/after work) or sex of the subject.

  15. Improvement of photodynamic activity of aluminium sulphophthalocyanine due to biotinylation

    NASA Astrophysics Data System (ADS)

    Meerovich, Irina G.; Jerdeva, Victoria V.; Derkacheva, Valentina M.; Meerovich, Gennadii A.; Lukyanets, Eugeny A.; Kogan, Eugenia A.; Savitsky, Alexander P.

    2003-09-01

    The photodynamic activity of dibiotinylated aluminium sulphophthalocyanine in vitro and in vivo were studied. It was obtained that in vitro dibiotinylated aluminium sulphophthalocyanine provides the effective damage of small cell lung carcinoma OAT-75. In vivo dibiotinylated aluminium sulphophthalocyanine causes destruction of tumor (Erlich carcinoma), results in total necrosis of tumor tissue and expresses vascular damage (trombosis and destruction of vascular walls) even in concentration 0.25 mg/kg of a body weight.

  16. Criticalities in crosslinked actin networks due to myosin activity

    NASA Astrophysics Data System (ADS)

    Sheinman, Michael

    2013-03-01

    Many essential processes in cells and tissues, like motility and morphogenesis, are orchestrated by molecular motors applying internal, active stresses on crosslinked networks of actin filaments. Using scaling analysis, mean-field calculation, numerical modelling and in vitro experiments of such active networks we predict and observe different mechanical regimes exhibiting interesting critical behaviours with non-trivial power-law dependencies. Firstly, we find that the presence of active stresses can dramatically increase the stiffness of a floppy network, as was observed in reconstituted intracellular F-actin networks with myosin motors and extracellular gels with contractile cells. Uniform internal stress results in an anomalous, critical mechanical regime only in the vicinity of the rigidity percolation points of the network. However, taking into account heterogeneity of motors, we demonstrate that the motors, stiffening any floppy network, induce large non-affine fluctuations, giving rise to a critical mechanical regime. Secondly, upon increasing motor concentration, the resulting large internal stress is able to significantly enhance unbinding of the network's crosslinks and, therefore, disconnect the initially well-connected network to isolated clusters. However, during this process, when the network approaches marginal connectivity the internal stresses are expected to drop drastically such that the connectivity stabilizes. This general argument and detailed numerical simulations show that motors should drive a well connected network to a close vicinity of a critical point of marginal connectivity. Experiments clearly confirm this conclusion and demonstrate robust critical connectivity of initially well-connected networks, ruptured by the motor activity for a wide range of parameters. M. Sheinman, C.P. Broedersz and F.C. MacKintosh, Phys. Rev. Lett, in press. J. Alvarado, M. Sheinman, A. Sharma, F.C. MacKintosh and G. Koenderink, in preparation.

  17. Energy deposition in the earth's atmosphere due to impact of solar activity-generated disturbances

    NASA Technical Reports Server (NTRS)

    Wu, S. T.; Kan, L. C.; Tandberg-Hanssen, E.; Dryer, M.

    1979-01-01

    Energy deposition in and dynamic responses of the terrestrial atmosphere to solar flare-generated shocks and other physical processes - such as particle precipitation and local heating - are investigated self-consistently in the context of hydrodynamics, the problem being treated as an initial boundary-value problem. It is extremely difficult to construct a general model for the line solar activity-magnetosphere-atmosphere; however, a limited model for this link is possible. The paper describes such a model, and presents some results on energy deposition into the earth's atmosphere due to solar activity-generated disturbances. Results from the present calculations are presented and discussed.

  18. Investigation of Biomechanical Response Due to Fragment Impact on Ballistic Protective Helmet.

    DTIC Science & Technology

    1998-03-01

    Investigation of Biomechanical Response Due to Fragment Impact on Ballistic Protective Helmet 5. FUNDING NUMBERS 6. AUTHOR( S ) King, Quinten M 7...fragments traveling in excess of 2000 ft/ s (609 m/ s ). However, these strides have also exposed the body to greater impact energies without a...development of personnel body armor capable of preventing penetration of fragments traveling in excess of 2000 ft/ s (609 m/ s ). However these strides have

  19. Density increase due to active feedback in mirror machine

    NASA Astrophysics Data System (ADS)

    Seemann, Omri; Be'Ery, Ilan

    2014-10-01

    Mirror machines are one of the schemes for future fusion systems. Its main drawbacks are the flute instability and being open ended which results in plasma losses. A feedback system is used to stabilize the flute instability in a table top mirror machine with a continuous plasma source and RF heating. Under certain source density and temperature conditions, although the plasma was stabilized, plasma density increase was not measured. After decreasing the source density and increasing the temperature, Plasma density increase was achieved. It is theorized that these results are due to transition of the plasma main loss mechanism from collision dominated to instability dominated. In the former, the main density loss is through diffusion and In the latter, it is through flute instability which drives the plasma to the edge of the vacuum chamber. Future research directions are discussed for a planned machine which should achieve higher temperatures and better diagnostic capabilities. The research will focus on magnetic actuators and passive RF stabilization.

  20. Landscape evolution due to river incision in active mountains

    NASA Astrophysics Data System (ADS)

    Lavé, L.; Attal, A.

    2003-04-01

    It is commonly accepted that fluvial network incision control the local base level for hillslopes and therefore controls the rate of landscape denudation, and thus the way the landscape will respond to tectonic or climatic forcings. For that reason, many studies have focused for the last ten years in quantifying fluvial incision rates and the mechanisms of fluvial incision into bedrock. In many morphotectonic settings the shear stress model has been widely used and provided satisfactory first order description of the river incision in active mountains. Across the Siwaliks range in front of the Himalaya, the shear stress model (that also includes bedload mean pebble size and explicit channel width variations), provides a good proxy to estimate incision and uplift rate, that can be measured independently from fluvial terraces studies. By transposition and after calibration to more resistant crystalline lithologies, this model helped to define the incision rate profiles across the whole Himalayan ranges. These profiles were found coherent with current seismotectonic model, sediment budget, fluvial terrace studies and geochronology results. More importantly, the incision model was found to provide good results in two other active regions: across the Nanga Parbat massif in Pakistan, and in the San Gabriel Ranges in California, with only minor required changes of the erodibility coefficient despite very different hydroclimatic setting. However, this semi-empirical model is not mechanically satisfying: in many settings, river bedload fluxes exert an important control on incision rates, by limiting bedrock exposure or by providing an efficient tool for river mechanical abrasion. A reappraisal of the former examples as thus conducted in order to test different models including the role of sediment fluxes. General results and models will be first discussed in light of their physical consistency with field and experimental data on pebble and bedrock abrasion, and second in

  1. Dynamics of radon activity due to earthquakes (by the example of Altai seismically active region)

    NASA Astrophysics Data System (ADS)

    Aptikaeva, O. I.; Shitov, A. V.

    2016-12-01

    The results of monitoring radon emanations in the territory of Gorno-Altaisk due to seismic activity and their influence on human health are considered. It is shown that the level of activity of subsoil radon in the vicinity of the fault zone in the territory of Gorno-Altaisk exceeds such a level recorded in Moscow by 3-4 times. There is ambiguity in the behavior of radon as a precursor of a seismic event. Some radon anomalies are synchronous with moments of earthquakes and others correspond to quiet periods. The radon activity is more closely associated with the earthquakes localized in the aftershock zone of the Chuya earthquake. This is assumed to be caused by the network of fluid-conducting channels within the active fault between this region and the observation station.

  2. Loss of factor VIII activity during storage in PVC containers due to adsorption.

    PubMed

    McLeod, A G; Walker, I R; Zheng, S; Hayward, C P

    2000-03-01

    Recombinant factor VIII concentrates are stable when administered in a reconstituted form according to the manufacturer's specifications, and undiluted via infusion with syringe mini-pumps. However many Haemophilia centres administer recombinant factor VIII further diluted in intravenous fluids for greater ease of administration. To investigate the stability of recombinant factor VIII during administration as a diluted infusion, reconstituted factor VIII was stored in polyvinylchloride (PVC) mini-bags undiluted (146 IU mL-1) and at factor VIII concentrations of 10 IU mL-1 and 2 IU mL-1. After 48 h of storage at room temperature in PVC mini-bags, the recoveries of factor VIII activity were 41.9% of the initial activity for the undiluted (146 IU mL-1) product and 43.7% of the initial activity for factor VIII diluted to 10 IU mL-1. For factor VIII diluted to 2 IU mL-1, the amount of factor VIII activity remaining at 48 h was only 1.8% of the initial activity. In contrast, 100% of factor VIII activity was recovered after 48 h when undiluted reconstituted product (146 IU mL-1) was stored in a syringe. To investigate the mechanism of factor VIII activity loss during storage, factor VIII samples collected after 0, 3 and 48 h of storage were analysed by immunoblotting with factor VIII antibodies. No evidence of factor VIII proteolytic degradation during storage was found, however, large amounts of factor VIII antigen were recovered from the empty PVC mini-bags following elution with denaturing detergent. We conclude that clinically significant losses of factor VIII activity occur during storage in PVC mini-bags and that the loss of activity is most likely due to protein adsorption onto the plastic surface. This loss of factor VIII activity during storage in PVC containers may substantially affect the safety and potential cost savings of administering recombinant factor VIII by continuous infusion.

  3. Investigating the Impacts of Surface Temperature Anomalies Due to Wildfires in Northern Sub-Saharan Africa

    NASA Astrophysics Data System (ADS)

    Gabbert, T.; Ichoku, C. M.; Matsui, T.; Capehart, W. J.

    2014-12-01

    The northern Sub-Saharan African region (NSSA) is an area of intense study due to the recent severe droughts that have dire consequences on the population, which relies mostly on rainfed agriculture for its food supply. This region's weather and hydrologic cycle are very complex and are dependent on the West African Monsoon. Different regional processes affect the West African Monsoon cycle and variability. One of the areas of current investigation is the water cycle response to the variability of land surface characteristics. Land surface characteristics are often altered in NSSA due to agricultural practices, grazing, and the fires that occur during the dry season. To better understand the effects of biomass burning on the hydrologic cycle of the sub-Saharan environment, an interdisciplinary team sponsored by NASA is analyzing potential feedback mechanisms due to the fires. As part of this research, this study focuses on the effects of land surface changes, particularly albedo and skin temperature, that are influenced by biomass burning. Surface temperature anomalies can influence the initiation of convective rainfall and surface albedo is linked to the absorption of solar radiation. To capture the effects of fire perturbations on the land surface, NASA's Unified Weather and Research Forecasting (NU-WRF) model coupled with NASA's Land Information System (LIS) is being used to simulate some of the fire-induced surface temperature anomalies and other environmental processes. In this presentation, we will report the strategy for these simulations, and show some preliminary results.

  4. Reduction of adsorption capacity of coconut shell activated carbon for organic vapors due to moisture contents.

    PubMed

    Abiko, Hironobu; Furuse, Mitsuya; Takano, Tsuguo

    2010-01-01

    In occupational hygiene, activated carbon produced from coconut shell is a common adsorbent material for harmful substances including organic vapors due to its outstanding adsorption capacity and cost advantage. However, moisture adsorption of the carbon generally decreases the adsorption capacity for organic vapors. In a previous report, we prepared several coconut shell activated carbons which had been preconditioned by equilibration with moisture at different relative humidities and measured the breakthrough times for 6 kinds of organic vapor, in order to clarify the effect of preliminary moisture content in activated carbon on the adsorption capacity in detail. We found that the relative percent weight increase due to moisture adsorption of the carbon specimen had a quantitative effect, reducing the breakthrough time. In this report, we carried out further measurements of the effect of moisture content on the adsorption of 13 kinds of organic vapor, and investigated the relationship between moisture adsorption and the reduction of the breakthrough time of activated carbon specimens. We also applied the data to the Wood's breakthrough time estimation model which is an extension of the Wheeler-Jonas equation.

  5. Numerical investigation of natural convection heat transfer in a cylindrical enclosure due to ultrasonic vibrations.

    PubMed

    Talebi, Maryam; Setareh, Milad; Saffar-Avval, Majid; Hosseini Abardeh, Reza

    2017-04-01

    Application of ultrasonic waves for heat transfer augmentation has been proposed in the last few decades. Due to limited researches on acoustic streaming induced by ultrasonic oscillation, the effect of ultrasonic waves on natural convection heat transfer is the main purpose of this paper. At first, natural convection on up-ward-facing heating surface in a cylindrical enclosure filled with air is investigated numerically by the finite difference method, then the effect of upper surface oscillation on convection heat transfer is considered. The conservation equations in Lagrangian approach and compressible fluid are assumed for the numerical simulation. Results show that acoustic pressure will become steady after some milliseconds also pressure oscillation amplitude and acoustic velocity components will be constant therefore steady state velocity is used for solving energy equation. Results show that Enhancement of heat transfer coefficient can be up to 175% by induced ultrasonic waves. In addition, the effect of different parameters on acoustic streaming and heat transfer has been studied.

  6. Experimental investigation of injectivity alteration due to salt precipitation during CO2 sequestration in saline aquifers

    NASA Astrophysics Data System (ADS)

    Jeddizahed, Javad; Rostami, Behzad

    2016-10-01

    Injection of CO2 into saline aquifers causes the geochemical reaction of rock-fluid and salt precipitation due to the evaporation of water as a physical process. Well injectivity is an important issue in carbon capture and storage (CCS) projects because large volumes of CO2 must be stored for a long time and salt precipitation can significantly reduce injectivity by reducing the permeability. The impact of salt precipitation on the injectivity must therefore be specified in order to maintain the security of CCS projects and enable them to perform at a high level of practicality. The objective of this work is to investigate the influence of the injection rate and brine salinity on injectivity reduction due to evaporation and salt precipitation. In this study, we injected supercritical CO2 into a sandstone rock sample fully saturated with NaCl brine to characterize the salt precipitation induced by the evaporation process. Evaporation is investigated by mass measurement of the water and vapor produced. The extension in time of salt precipitation and the precipitation profile are analyzed by drying rate measurement, Capillary number and Peclet number. The consequences of salt precipitation on injectivity are specified by permeability and relative permeability analysis. The results show that a high drying rate in the early stage of injection induces rapid salt precipitation. The level of salt precipitation increases with salinity, within a permeability reduction range of 21-66%, and decreases with the injection rate, within a permeability reduction range of 43-62%. The relative permeability of CO2 is affected by both the injection rate and salinity.

  7. Numerical investigations of triggering mechanisms of shallow landslides due to heterogeneous spatio-temporal hydrological patterns.

    NASA Astrophysics Data System (ADS)

    Schwarz, Massimiliano; Cohen, Denis

    2016-04-01

    regional scale rely on the infinite slope assumption for stability calculations and on continuous hydrological properties of the soil. The objective of the present study is to investigate the influence of non-continuos hydrological features (such as ephemeral springs) on the triggering mechanisms of shallow landslides using a discrete element model (SOSlope) in which the stress-strain behavior of soil is explicitly considered. The application of a stress-strain calculation allows for the simulation of local versus global loading due to hydrological processes. In particular, this study investigates the effects of different types of hydrological loading on the force redistribution on a slope associated with local displacements and following failures of soil masses. Strength and stiffness of soil are considered heterogeneous and are calculated based on the assumption of root distributions within a forested hillslope.

  8. An Experimental Investigation of the Structural Wave Scattering Due to Impedance Discontinuities on a Cylindrical Structure

    SciTech Connect

    Glotzbecker, Ryan Joseph

    2006-05-01

    Experimental, numerical, and analytical work has shown that the response of a shell to a distributed force wave possesses unique characteristics which are dependent on the nature of structure attached to the shell. Specific characteristics which influence the response are the distribution of the discontinuities around the circumference (periodic/aperiodic), the impedance of the discontinuities relative to that of the shell, and the type of impedance (mass or stiffness). Traditional shell theory predicts low frequency, radial-dominated structural mode shapes of a shell with a sinusoidal distribution of displacement amplitudes. Due to the orthogonal nature of these mode shapes, the response of the structure to a traveling radial force wave with sinusoidal content at a given harmonic is due solely to the response of the mode shape with harmonic content of the same order. Introduction of impedance discontinuities to a shell yield complex mode shapes, which may be characterized by the summation of several harmonic components. These modes are no longer orthogonal in the presence of discontinuities, yielding harmonic content across various modal orders. As a result, a purely sinusoidal forcing function can excite several modes of the structure. Structural scattering as discussed in this paper refers to the phenomena in which a force wave at a given harmonic scatters into the response of modes with different harmonics. An experimental investigation into the harmonic scattering behavior of a shell due to mass discontinuities is presented in this paper. Knowledge of the key structural characteristics which influence scattering and their behavior will allow for a diagnostic tool when assessing the structural response of more complex cylindrical structures. Experimentally obtained data presented in this paper demonstrates some expected scattering characteristics of a cylindrical shell in the presence of periodically and aperiodically distributed masses. Some unique

  9. Commissioning of a motion system to investigate dosimetric consequences due to variability of respiratory waveforms.

    PubMed

    Cetnar, Ashley J; James, Joshua; Wang, Brain

    2016-01-01

    A commercially available six-dimensional (6D) motion system was assessed for accuracy and clinical use in our department. Positional accuracy and respiratory waveform reproducibility were evaluated for the motion system. The system was then used to investigate the dosimetric consequences of respiratory waveform variation when an internal target volume (ITV) approach is used for motion management. The maximum deviations are 0.3 mm and 0.22° for translation and rotation accuracy, respectively, for the tested clinical ranges. The origin reproducibility is less than ±0.1 mm. The average differences are less than 0.1 mm with a maximum standard deviation of 0.8 mm between waveforms of actual patients and replication of those waveforms by HexaMotion for three breath-hold and one free-breathing waveform. A modified gamma analysis shows greater than 98% agreement with a 0.5 mm and 100 ms threshold. The motion system was used to investigate respiratory waveform variation and showed that, as the amplitude of the treatment waveform increases above that of the simulation waveform, the periphery of the target volume receives less dose than expected. However, by using gating limits to terminate the beam outside of the simulation amplitude, the results are as expected dosimetrically. Specifically, the average dose difference in the periphery between treating with the simulation waveform and the larger amplitude waveform could be up to 12% less without gating limits, but only differed 2% or less with the gating limits in place. The general functionality of the system performs within the manufacturer's specifications and can accurately replicate patient specific waveforms. When an ITV approach is used for motion management, we found the use of gating limits that coincide with the amplitude of the patient waveform at simulation helpful to prevent the potential underdosing of the target due to changes in patient respiration. PACS numbers: 87.55.Kh, 87.55.Qr, 87.56.Fc.

  10. Commissioning of a motion system to investigate dosimetric consequences due to variability of respiratory waveforms.

    PubMed

    Cetnar, Ashley J; James, Joshua; Wang, Brain

    2016-01-08

    A commercially available six-dimensional (6D) motion system was assessed for accuracy and clinical use in our department. Positional accuracy and respiratory waveform reproducibility were evaluated for the motion system. The system was then used to investigate the dosimetric consequences of respiratory waveform variation when an internal target volume (ITV) approach is used for motion management. The maximum deviations are 0.3 mm and 0.22° for translation and rotation accuracy, respectively, for the tested clinical ranges. The origin reproducibility is less than±0.1 mm. The average differences are less than 0.1 mm with a maximum standard deviation of 0.8 mm between waveforms of actual patients and replication of those waveforms by HexaMotion for three breath-hold and one free-breathing waveform. A modified gamma analysis shows greater than 98% agreement with a 0.5 mm and 100 ms threshold. The motion system was used to investigate respiratory waveform variation and showed that, as the amplitude of the treatment waveform increases above that of the simulation waveform, the periphery of the target volume receives less dose than expected. However, by using gating limits to terminate the beam outside of the simulation amplitude, the results are as expected dosimetrically. Specifically, the average dose difference in the periphery between treating with the simulation waveform and the larger amplitude waveform could be up to 12% less without gating limits, but only differed 2% or less with the gating limits in place. The general functionality of the system performs within the manufacturer's specifications and can accurately replicate patient specific waveforms. When an ITV approach is used for motion management, we found the use of gating limits that coincide with the amplitude of the patient waveform at simulation helpful to prevent the potential underdosing of the target due to changes in patient respiration.

  11. 48 CFR 9903.201-8 - Compliant accounting changes due to external restructuring activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... changes due to external restructuring activities. 9903.201-8 Section 9903.201-8 Federal Acquisition... Requirements 9903.201-8 Compliant accounting changes due to external restructuring activities. The contract price and cost adjustment requirements of this part 9903 are not applicable to compliant cost...

  12. Investigation of energy dissipation due to contact angle hysteresis in capillary effect

    NASA Astrophysics Data System (ADS)

    Athukorallage, Bhagya; Iyer, Ram

    2016-06-01

    Capillary action or Capillarity is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces like gravity. Three effects contribute to capillary action, namely, adhesion of the liquid to the walls of the confining solid; meniscus formation; and low Reynolds number fluid flow. We investigate the dissipation of energy during one cycle of capillary action, when the liquid volume inside a capillary tube first increases and subsequently decreases while assuming quasi-static motion. The quasi-static assumption allows us to focus on the wetting phenomenon of the solid wall by the liquid and the formation of the meniscus. It is well known that the motion of a liquid on an non-ideal surface involves the expenditure of energy due to contact angle hysteresis. In this paper, we derive the equations for the menisci and the flow rules for the change of the contact angles for a liquid column in a capillary tube at a constant temperature and volume by minimizing the Helmholtz free energy using calculus of variations. We describe the numerical solution of these equations and present results from computations for the case of a capillary tube with 1 mm diameter.

  13. Progressive anterior operculum syndrome due to FTLD-TDP: a clinico-pathological investigation.

    PubMed

    Otsuki, Mika; Nakagawa, Yoshitsugu; Mori, Fumiaki; Tobioka, Hirotoshi; Yoshida, Hideaki; Tatezawa, Yoshiharu; Tanigawa, Toshio; Takahashi, Ikuko; Yabe, Ichiro; Sasaki, Hidenao; Wakabayashi, Koichi

    2010-07-01

    Pathological investigation of progressive anterior operculum syndrome has rarely been reported. We describe clinico-pathological findings in a patient with progressive anterior operculum syndrome. A 74-year-old right-handed man had noticed speech and swallowing difficulties 1 year previously. Neurological examinations showed no abnormality other than a slight limitation of upward gaze and slow tongue movement without fibrillation. We investigated the patient using neuroimaging and neuropsychological examinations and observed him for 2 years until his death, at which point we obtained pathological findings. The patient's facial and masseteric muscles seemed hypotonic with drooling, but he could laugh and yawn normally, showing automatic voluntary dissociation. Palatal and pharyngeal reflexes were normal. Magnetic resonance imaging showed cortical atrophy in the temporal lobes bilaterally. (123)IMP single photon emission computed tomography and positron emission tomography showed decreased blood flow and activity in the frontotemporal lobes, predominantly on the left side. Neuropsychological examinations showed no aphasia, dementia or other neuropsychological abnormality. Intubation fiberscopy, laryngoscopy and video fluorography showed no abnormality. After 6 months his anarthria and dysphagia became aggravated. He died of aspiration pneumonia 2 years after onset. Postmortem examination revealed neuronal degeneration with TDP-43-positive inclusions in the frontal, temporal and insular cortices, consistent with frontotemporal lobar degeneration with TDP inclusions (FTLD-TDP). However, neuronal loss with gliosis was more prominent in the inferior part of the motor cortices, bilaterally. Progressive anterior operculum syndrome could be classified as a variant of FTLD-TDP.

  14. Investigation of dental pulp stem cells isolated from discarded human teeth extracted due to aggressive periodontitis.

    PubMed

    Sun, Hai-Hua; Chen, Bo; Zhu, Qing-Lin; Kong, Hui; Li, Qi-Hong; Gao, Li-Na; Xiao, Min; Chen, Fa-Ming; Yu, Qing

    2014-11-01

    Recently, human dental pulp stem cells (DPSCs) isolated from inflamed dental pulp tissue have been demonstrated to retain some of their pluripotency and regenerative potential. However, the effects of periodontal inflammation due to periodontitis and its progression on the properties of DPSCs within periodontally compromised teeth remain unknown. In this study, DPSCs were isolated from discarded human teeth that were extracted due to aggressive periodontitis (AgP) and divided into three experimental groups (Groups A, B and C) based on the degree of inflammation-induced bone resorption approaching the apex of the tooth root before tooth extraction. DPSCs derived from impacted or non-functional third molars of matched patients were used as a control. Mesenchymal stem cell (MSC)-like characteristics, including colony-forming ability, proliferation, cell cycle, cell surface antigens, multi-lineage differentiation capability and in vivo tissue regeneration potential, were all evaluated in a patient-matched comparison. It was found that STRO-1- and CD146-positive DPSCs can be isolated from human teeth, even in very severe cases of AgP. Periodontal inflammation and its progression had an obvious impact on the characteristics of DPSCs isolated from periodontally affected teeth. Although all the isolated DPSCs in Groups A, B and C showed decreased colony-forming ability and proliferation rate (P < 0.05), the decreases were not consistent with the degree of periodontitis. Furthermore, the cells did not necessarily show significantly diminished in vitro multi-differentiation potential. Only DPSCs from Group A and the Control group formed dentin-like matrix in vivo when cell-seeded biomaterials were transplanted directly into an ectopic transplantation model. However, when cell-seeded scaffolds were placed in the root fragments of human teeth, all the cells formed significant dentin- and pulp-like tissues. The ability of DPSCs to generate dental tissues decreased when the

  15. Hyperpolarization of rabbit superior cervical ganglion cells due to activity of an electrogenic sodium pump

    PubMed Central

    Lees, G.M.; Wallis, D.I.

    1974-01-01

    1 The mechanisms underlying the hyperpolarization which follows depolarization of rabbit superior cervical ganglion cells by acetylcholine, have been investigated and compared with the mechanisms responsible for the hyperpolarizations induced by orthodromic stimulation of the ganglion. 2 The amplitude of the drug-induced hyperpolarization (after-hyperpolarization) was diminished when [Na+]0 and the duration of the preceding depolarization were reduced. 3 In K+-free solutions, the amplitude of the after-hyperpolarization was often diminished and its rate of development was reduced. In 12.5 mM K+-Krebs solutions, the amplitude and rate of development of the after-hyperpolarization were increased; the potential was still present when the resting potential was at or close to EK. 4 Ouabain (10 μM) prevented or greatly diminished the after-hyperpolarization. The rates of onset and decay of the after-hyperpolarization were reduced in glucose-free solutions. 5 It is, therefore, concluded that the after-hypolarization is due to the activity of an electrogenic sodium pump. 6 The positive after-potential associated with the ganglionic action potential was increased in K+-free solutions and diminished when the resting potential approached EK, indicating that it is due to a period of increased K+ conductance. In the presence of high concentrations of hexamethonium (276 μM), the P wave was not selectively depressed by ouabain and has been shown by other workers to be due to a mechanism not involving an increased potassium conductance. It is concluded, therefore, that the positive after-potential, the P wave and the after-hyperpolarization are due to different mechanisms. PMID:4823465

  16. Ethanolamine requirement of mammary epithelial cells is due to reduced activity of base exchange enzyme

    SciTech Connect

    Kano-Sueoka, T.; King, D.M.

    1987-05-01

    Epithelial cells and some of their transformed derivatives require ethanolamine (Etn) to proliferate normally in defined culture medium. The amount of cellular phosphatidylethanolamine (PtdEtn) is considerably reduced when these cells are cultured without Etn. Using Etn-responsive and -nonresponsive rat mammary carcinoma cell lines, the biochemical mechanism of Etn-responsiveness of investigated. The incorporation of (/sup 3/H)serine into phosphatidylserine (PtdSer) and PtdEtn in Etn-responsive cells was 60 and 37%, respectively, of those in Etn-nonresponsive cells. There was no significant difference between the two cell types in the activities of enzymes involved in PtdEtn synthesis via CDP-Etn. The activity of PtdSer decarboxylase was also very similar in these two cell types. When these cells were cultured in the presence of (/sup 32/P)PtdEtn, the rate of accumulation of (/sup 32/P)-labeled PtdSer from the radioactive PtdEtn was considerably reduced in Etn-responsive cells as compared to Etn-nonresponsive cells. Whereas there was no significant difference in the accumulation of the labeled PtdSer from (/sup 32/P)phosphatidylcholine. These results demonstrate that the Etn-responsiveness is due to a limited ability to synthesize PtdSer resulting from a limited base exchange activity utilizing PtdEtn.

  17. Geometric investigation of a gaming active device

    NASA Astrophysics Data System (ADS)

    Menna, Fabio; Remondino, Fabio; Battisti, Roberto; Nocerino, Erica

    2011-07-01

    3D imaging systems are widely available and used for surveying, modeling and entertainment applications, but clear statements regarding their characteristics, performances and limitations are still missing. The VDI/VDE and the ASTME57 committees are trying to set some standards but the commercial market is not reacting properly. Since many new users are approaching these 3D recording methodologies, clear statements and information clarifying if a package or system satisfies certain requirements before investing are fundamental for those users who are not really familiar with these technologies. Recently small and portable consumer-grade active sensors came on the market, like TOF rangeimaging cameras or low-cost triangulation-based range sensor. A quite interesting active system was produced by PrimeSense and launched on the market thanks to the Microsoft Xbox project with the name of Kinect. The article reports the geometric investigation of the Kinect active sensors, considering its measurement performances, the accuracy of the retrieved range data and the possibility to use it for 3D modeling application.

  18. Analytical investigation of fan tone noise due to ingested atmospheric turbulence

    NASA Technical Reports Server (NTRS)

    Ganz, U. W.

    1980-01-01

    The atmospheric turbulence involved in the fan noise generation is evaluated with an existing model for the atmospheric turbulence and an extended version of an existing model concerned with the effects of a flow contraction on convected turbulence. Fan tone noise due to ingested atmospheric turbulence is evaluated with existing fan noise models. The results indicate that the difference in fan narrowband noise due to atmospheric turbulence between static and flight landing approach conditions is in the order of 30 dB. It is concluded that fan noise due to atmospheric turbulence is insignificant in flight conditions for the fans used in the current high bypass ratio engines. The difference in fan narrowband noise between the two conditions is primarily due to the low intensity of the turbulence involved in fan noise generation in flight conditions. Fan noise due to atmospheric turbulence in static conditions should be reduced below the flight fan broadband noise levels which is best achieved with a reduction in the intensity of the fan inflow turbulence. Such a reduction can be obtained with the use of an inflow control device, low wind velocities, small surface roughness in the test stand environment, and large engine axis height above the ground. Peak sound power levels for fan tone noise due to ingested turbulence occur for transverse integral scales in the order of 25% of the rotor blade spacing in the fan tip region.

  19. Lactobacillus plantarum phytase activity is due to non-specific acid phosphatase.

    PubMed

    Zamudio, M; González, A; Medina, J A

    2001-03-01

    Microbial phytases suitable for food fermentations could be obtained from lactic acid bacteria isolated from natural vegetable fermentations. Phytase activity was evaluated for six lactic acid bacteria cultures. Although the highest activity was found for Lactobacillus plantarum, the phytase activity was very low. Further characterization of the enzyme with phytate-degrading activity showed a molecular weight of 52 kDa and an optimum activity at pH 5.5 and 65 degrees C. Enzyme activity was due to a non-specific acid phosphatase which had a higher hydrolysis rate with monophosphorylated compounds such as acetyl phosphate that could explain the low phytase activity.

  20. TRADEOFFs in climate effects through aircraft routing: forcing due to radiatively active gases

    NASA Astrophysics Data System (ADS)

    Stordal, F.; Gauss, M.; Myhre, G.; Mancini, E.; Hauglustaine, D. A.; Köhler, M. O.; Berntsen, T.; . G Stordal, E. J.; Iachetti, D.; Pitari, G.; Isaksen, I. S. A.

    2006-10-01

    We have estimated impacts of alternative aviation routings on the radiative forcing. Changes in ozone and OH have been estimated in four Chemistry Transport Models (CTMs) participating in the TRADEOFF project. Radiative forcings due to ozone and methane have been calculated accordingly. In addition radiative forcing due to CO2 is estimated based on fuel consumption. Three alternative routing cases are investigated; one scenario assuming additional polar routes and two scenarios assuming aircraft cruising at higher (+2000 ft) and lower (-6000 ft) altitudes. Results from the base case in year 2000 are included as a reference. Taking first a steady state backward looking approach, adding the changes in the forcing from ozone, CO2 and CH4, the ranges of the models used in this work are -0.8 to -1.8 and 0.3 to 0.6 m Wm-2 in the lower (-6000 ft) and higher (+2000 ft) cruise levels, respectively. In relative terms, flying 6000ft lower reduces the forcing by 5-10% compared to the current flight pattern, whereas flying higher, while saving fuel and presumably flying time, increases the forcing by about 2-3%. Taking next a forward looking approach we have estimated the integrated forcing (m Wm-2 yr) over 20 and 100 years time horizons. The relative contributions from each of the three climate gases are somewhat different from the backward looking approach. The differences are moderate adopting 100 year time horizon, whereas under the 20 year horizon CO2 naturally becomes less important relatively. Thus the forcing agents impact climate differently on various time scales. Also, we have found significant differences between the models for ozone and methane. We conclude that we are not yet at a point where we can include non-CO2 effects of aviation in emission trading schemes. Nevertheless, the rerouting cases that have been studied here yield relatively small changes in the radiative forcing due to the radiatively active gases.

  1. Investigation of VOC Transport in Soil Vapors due to Wind Effects using Models and Measurement

    NASA Astrophysics Data System (ADS)

    Pennell, K. G.; Roghani, M.; Shirazi, E.; Willett, E.

    2014-12-01

    For the past several years, vapor intrusion of volatile organic compounds (VOCs) that emanate from hazardous waste sites has been gaining attention due to adverse health effects and regulatory action. Most studies of VOC vapor intrusion suggest that diffusion is the dominant contaminant transport mechanism, while advection is only considered important near contaminant entry points (i.e. building cracks). This conceptual framework is accurate when above-ground surface features do not promote air flow into (or out of) the ground surface. Recent research related to air flow in the atmospheric boundary layer (ABL) due to wind effects around buildings suggests a need for better understanding how advective transport processes can impact contaminant profiles and vapor intrusion exposure risks. In this study, a numerical model using COMSOL Multiphysics was developed to account for parameters affecting the transport of VOCs from the subsurface into buildings by considering wind effects in the ABL. Model simulations are compared to preliminary laboratory and field data to evaluate the relative importance of wind induced pressure gradients, soil permeability, soil porosity, and soil effective diffusivity on vapor intrusion entry rates. The major goal of this research is to develop an improved conceptual understanding of the vapor intrusion process so that remediation efforts can be better designed and implemented.

  2. MSFC Investigations of Beta Cloth Darkening Due to Ultraviolet Radiation Interactions

    NASA Technical Reports Server (NTRS)

    Kamenetzky, Rachel R.; Finckenor, Miria M.

    1999-01-01

    A common component of multi-layer insulation blankets is beta cloth, a woven fiberglass cloth impregnated with Teflon. It is planned for extensive use on the International Space Station (ISS). The Environmental Effects Group of the Marshall Space Flight Center Materials, Processing and Manufacturing Department has investigated the impact of atomic oxygen (AO) and ultraviolet (UV) radiation on the optical properties of plain and aluminized beta cloth, both in the laboratory and as part of long-duration flight experiments. These investigations indicate that beta cloth was susceptible to darkening in the presence of UV radiation, dependent on the additives used. The presence of AO countered some, if not all, of the UV degradation.

  3. Unsteady loads due to propulsive lift configurations. Part A: Investigation of scaling laws

    NASA Technical Reports Server (NTRS)

    Morton, J. B.; Haviland, J. K.

    1978-01-01

    This study covered scaling laws, and pressure measurements made to determine details of the large scale jet structure and to verify scaling laws by direct comparison. The basis of comparison was a test facility at NASA Langley in which a JT-15D exhausted over a boilerplater airfoil surface to reproduce upper surface blowing conditions. A quarter scale model was built of this facility, using cold jets. A comparison between full scale and model pressure coefficient spectra, presented as functions of Strouhal numbers, showed fair agreement, however, a shift of spectral peaks was noted. This was not believed to be due to Mach number or Reynolds number effects, but did appear to be traceable to discrepancies in jet temperatures. A correction for jet temperature was then tried, similar to one used for far field noise prediction. This was found to correct the spectral peak discrepancy.

  4. INVESTIGATION OF AMMONIA ADSORPTION ON FLY ASH DUE TO INSTALLATION OF SELECTIVE CATALYTIC REDUCTION SYSTEMS

    SciTech Connect

    G.F. Brendel; J.E. Bonetti; R.F. Rathbone; R.N. Frey Jr.

    2000-11-01

    This report summarizes an investigation of the potential impacts associated with the utilization of selective catalytic reduction (SCR) systems at coal-fired power plants. The study was sponsored by the U.S. Department of Energy Emission Control By-Products Consortium, Dominion Generation, the University of Kentucky Center for Applied Energy Research and GAI Consultants, Inc. SCR systems are effective in reducing nitrogen oxides (NOx) emissions as required by the Clean Air Act (CAA) Amendments. However, there may be potential consequences associated with ammonia contamination of stack emissions and combustion by-products from these systems. Costs for air quality, landfill and pond environmental compliance may increase significantly and the marketability of ash may be seriously reduced, which, in turn, may also lead to increased disposal costs. The potential impacts to air, surface water, groundwater, ash disposal, ash utilization, health and safety, and environmental compliance can not be easily quantified based on the information presently available. The investigation included: (1) a review of information and data available from published and unpublished sources; (2) baseline ash characterization testing of ash samples produced from several central Appalachian high-volatile bituminous coals from plants that do not currently employ SCR systems in order to characterize the ash prior to ammonia exposure; (3) an investigation of ammonia release from fly ash, including leaching and thermal studies; and (4) an evaluation of the potential impacts on plant equipment, air quality, water quality, ash disposal operations, and ash marketing.

  5. Investigation of air pollution and regional climate change due to anthropogenic aerosols

    NASA Astrophysics Data System (ADS)

    Nakata, Makiko; Sano, Itaru; Mukai, Sonoyo

    2016-10-01

    Increased emissions of anthropogenic aerosols associated with economic growth can lead to increased concentrations of hazardous air pollutants. In particular, large cities in East Asia have experienced numerous heavy haze episodes. Atmospheric aerosol distributions in East Asia are complex, being influenced by both natural phenomena and human activity, with urban areas in particular being dominated by fine anthropogenic aerosols released from diesel-powered vehicles and industrial activity. In Japan, air pollution levels have been reduced; nevertheless, in recent years, there is increasing concern regarding air pollution caused by fine particulate matter. The origins of air pollution were examined, focusing on the comparison between aerosol properties observed from satellites and that on the ground. Because of their short life spans, concentrations of anthropogenic aerosols are highest over the source regions, and as a result, the climatic impacts of anthropogenic aerosols are also found to be most pronounced in these regions. In this study, aerosol impacts on climate are assessed by numerical model simulations. The direct effects of aerosols include reduced solar radiation, and hence a decrease in surface temperatures. In addition to these changes in the radiation budget, aerosols have a significant potential to change cloud and precipitation fields. These climatic responses to aerosols can manifest far from their source regions with high industrial activities.

  6. [Ergotism due to simultaneous use of ergot alkaloids and high activity antiretroviral therapy].

    PubMed

    Cifuentes M, Daniel; Blanco L, Sergio; Ramírez F, Camila

    2016-06-01

    High activity antiretroviral therapy may exacerbate the activity of ergot alkaloids due to an inhibition of cytochrome P450. We report a 57 years old female with AIDS treated with lamivudine, zidovudine, atazanavir, ritonavir and cotrimoxazole presenting with ischemic signs in the four limbs. There was acrocyanosis and weak radial and ulnar pulses. A family member referred that the patient used ergot alkaloids for headaches. An ergotism due to the simultaneous use of ergot alkaloids and antiretroviral therapy was suspected. The latter was discontinued and intravenous nitroglycerin, nifedipine and pentoxifyline were started with good results.

  7. Investigating treatment dose error due to beam attenuation by a carbon fiber tabletop.

    PubMed

    Myint, W Kenji; Niedbala, Malgorzata; Wilkins, David; Gerig, Lee H

    2006-08-24

    Carbon fiber is commonly used in radiation therapy for treatment tabletops and various immobilization and support devices, partially because it is generally perceived to be almost radiotransparent to high-energy photons. To avoid exposure to normal tissue during modern radiation therapy, one must deliver the radiation from all gantry angles; hence, beams often transit the couch proximal to the patient. The effects of the beam attenuation by the support structure of the couch are often neglected in the planning process. In this study, we investigate the attenuation of 6-MV and 18-MV photon beams by a Medtec (Orange City, IA) carbon fiber couch. We have determined that neglecting the attenuation of oblique treatment fields by the carbon fiber couch can result in localized dose reduction from 4% to 16%, depending on energy, field size, and geometry. Further, we investigate the ability of a commercial treatment-planning system (Theraplan Plus v3.8) to account for the attenuation by the treatment couch. Results show that incorporating the carbon fiber couch in the patient model reduces the dose error to less than 2%. The variation in dose reduction as a function of longitudinal couch position was also measured. In the triangular strut region of the couch, the attenuation varied +/- 0.5% following the periodic nature of the support structure. Based on these findings, we propose the routine incorporation of the treatment tabletop into patient treatment planning dose calculations.

  8. Investigation on the buckling of steel piers of elevated expressway due to the Great Hanshin Earthquake

    SciTech Connect

    Fujita, Katsuhisa; Nakamura, Kazuhiro; Ito, Tomohiro; Iwamoto, Yoichi

    1996-12-01

    In the Great Hanshin Earthquake which occurred in January 1995, extremely serious damages to the elevated expressways were found. Some of those piers are made of steel and many of them buckled and revealed plastic deformations. One of them revealed the circumferentially uniform outward bulge at the middle portion in the axial direction, though the buckling of a long circular cylinder will occur at it`s bottom end accompanied by more complicated deformation patterns typical to the bending buckling. In this study, simple reduced scale models of the pier were fabricated and the dynamic and static buckling tests were performed. The effect of the girder weight or vertical excitation on the buckling phenomena were investigated. In addition to the tests, static buckling analysis using FEM was also performed in order to clarify the causes for this specified buckling phenomena.

  9. A Monte Carlo investigation of contaminant electrons due to a novel in vivo transmission detector.

    PubMed

    Asuni, G; Jensen, J M; McCurdy, B M C

    2011-02-21

    A novel transmission detector (IBA Dosimetry, Germany) developed as an IMRT quality assurance tool, intended for in vivo patient dose measurements, is studied here. The goal of this investigation is to use Monte Carlo techniques to characterize treatment beam parameters in the presence of the detector and to compare to those of a plastic block tray (a frequently used clinical device). Particular attention is paid to the impact of the detector on electron contamination model parameters of two commercial dose calculation algorithms. The linac head together with the COMPASS transmission detector (TRD) was modeled using BEAMnrc code. To understand the effect of the TRD on treatment beams, the contaminant electron fluence, energy spectra, and angular distributions at different SSDs were analyzed for open and non-open (i.e. TRD and block tray) fields. Contaminant electrons in the BEAMnrc simulations were separated according to where they were created. Calculation of surface dose and the evaluation of contributions from contaminant electrons were performed using the DOSXYZnrc user code. The effect of the TRD on contaminant electrons model parameters in Eclipse AAA and Pinnacle(3) dose calculation algorithms was investigated. Comparisons of the fluence of contaminant electrons produced in the non-open fields versus open field show that electrons created in the non-open fields increase at shorter SSD, but most of the electrons at shorter SSD are of low energy with large angular spread. These electrons are out-scattered or absorbed in air and contribute less to surface dose at larger SSD. Calculated surface doses with the block tray are higher than those with the TRD. Contribution of contaminant electrons to dose in the buildup region increases with increasing field size. The additional contribution of electrons to surface dose increases with field size for TRD and block tray. The introduction of the TRD results in a 12% and 15% increase in the Gaussian widths used in the

  10. An investigation of bloodborne pathogen transmission due to multipatient sharing of insulin pens.

    PubMed

    Hakre, Shilpa; Upshaw-Combs, Donna R; Sanders-Buell, Eric E; Scoville, Stephanie L; Kuper, Joshua D; Jagodzinski, Linda L; Bradfield, Andrea N; Davison, Dinae C; Callis, William G; Owens, Angela B; Michael, Nelson L; O'Connell, Robert J; Peel, Sheila A; Gardner, John W; Thompson, Nicola D; Hu, Dale J; Kim, Jerome H; Tovanabutra, Sodsai; Scott, Paul T; LaFon, Sandra G

    2012-08-01

    On January 30, 2009, nursing staff at a military hospital in Texas reported that single-patient use insulin pens were used on multiple patients. An investigation was initiated to determine if patient-to-patient bloodbome transmission occurred from the practice. Human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) testing was offered to patients hospitalized from August 2007 to January 2009 and prescribed insulin pen injections. Virus from HCV-infected patients' sera was sequenced and compared for relatedness. An anonymous survey was administered to nurses. Of 2,113 patients prescribed insulin pen injections, 1,501 (71%) underwent testing; 6 (0.4%) were HIV positive, 6 (0.4%) were hepatitis B surface antigen positive, and 56 (3.7%) had HCV antibody. No viral sequences from 10 of 28 patients with newly diagnosed and 12 of 28 patients with preexisting HCV infection were closely related. Of 54 nurses surveyed, 74% reported being trained on insulin pen use, but 24% believed nurses used insulin pens on more than one patient. We found no clear evidence of bloodborne pathogen transmission. Training of hospital staff on correct use of insulin pens should be prioritized and their practices evaluated. Insulin pens should be more clearly labeled for single-patient use.

  11. An investigation of vortical flowfields due to single and multiple surface perturbations at the forebody

    NASA Astrophysics Data System (ADS)

    Hamilton, Howard Hugh

    Vortical flowfields produced by one and two cylindrical surface perturbations at the apex of a blunted conical forebody were investigated as a function of geometric parameters that defined the perturbation: axial position, perturbation height, and circumferential position. Static side force and yaw moment measurements, smoke- and oil-flow visualizations and flowfield mappings were used to correlate changes in the flow physics with the aerodynamic loads. The flow physics at the perturbation were dominated by the presence of a horseshoe vortex at the base of the surface perturbation and three-dimensional wake shedding along its height. These phenomena created a region of high Reynolds shear stresses and fluctuation velocities that deformed locally the separation and reattachment lines and increased the strength of the secondary vortex. Nonlinear regressions of the aerodynamic loads as a function of the geometric parameters revealed a fractional power-law dependence of the decay rate of the loads on the perturbation height and a stronger power-law dependence of the growth rate on the axial position. A discrete vortex simulation of the flowfield in which the effect of the perturbations was simulated as a shift in shed vortex particles confirmed these dependencies. A pair of perturbations of equal height located at the same axial position but on opposite sides of the forebody manipulated the separation lines and the related vortices independently of each other. Perturbations placed on the same side of the forebody created flowfields that were dependent of the angular spacing between the pair and the circumferential position of the perturbations. It was concluded that although the presence of single and multiple surface perturbations was sufficient to deform the local surface skin-friction lines, they were not sufficient to change the global topological structure of the mean skin-friction patterns. This change in the topological structure is postulated to be sufficient

  12. Investigating Nitrogen Pollution: Activities and Models.

    ERIC Educational Resources Information Center

    Green Teacher, 2000

    2000-01-01

    Introduces activities on nitrogen, nitrogen pollution from school commuters, nitrogen response in native and introduced species, and nutrient loading models. These activities help students determine the nitrogen contribution from their parents' cars, test native plant responses to nitrogen, and experiment with the results of removing water from…

  13. Absence of in vitro Procoagulant Activity in Immunoglobulin Preparations due to Activated Coagulation Factors

    PubMed Central

    Oviedo, Adriana E.; Bernardi, María E.; Guglielmone, Hugo A.; Vitali, María S.

    2015-01-01

    Summary Background Immunoglobulin (IG) products, including intravenous (IVIG) or subcutaneous (SCIG) immunoglobulins are considered safe and effective for medical therapy; however, a sudden and unexpected increase in thromboembolic events (TE) after administration of certain batches of IVIG products has been attributed to the presence of activated coagulation factors, mainly factor XIa. Our aims were to examine the presence of enduring procoagulant activity during the manufacturing process of IGs, with special focus on monitoring factor XIa, and to evaluate the presence of in vitro procoagulant activity attributed to coagulation factors in different lots of IVIG and SCIG. Methods Samples of different steps of IG purification, 19 lots of IVIG and 9 of SCIG were analyzed and compared with 1 commercial preparation of IVIG and 2 of SCIG, respectively. Factors II, VII, IX, XI and XIa and non-activated partial thromboplastin time (NAPTT) were assayed. Results The levels of factors II, VII, IX, X and XI were non-quantifiable once fraction II had been re-dissolved and in all analyzed lots of IVIG and SCIG. The level of factor XIa at that point was under the detection limits of the assay, and NAPTT yielded values greater than the control during the purification process. In SCIG, we detected higher concentrations of factor XIa in the commercial products, which reached values up to 5 times higher than the average amounts found in the 9 batches produced by UNC-Hemoderivados. Factor XIa in commercial IVIG reached levels slightly higher than those of the 19 batches produced by UNC-Hemoderivados. Conclusion IVIG and SCIG manufactured by UNC-Hemoderivados showed a lack of thrombogenic potential, as demonstrated not only by the laboratory data obtained in this study but also by the absence of any reports of TE registered by the post marketing pharmacovigilance department. PMID:26733772

  14. 76 FR 20707 - Notice of Possible Shutdown of Investigative Activities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-13

    ... determined to shut down its investigative activities in the event of the absence of an appropriation. FOR... shut down its investigative activities for the duration of the absence of appropriation....

  15. Fhl2 deficiency results in osteopenia due to decreased activity of osteoblasts

    PubMed Central

    Günther, Thomas; Poli, Cecilia; Müller, Judith M; Catala-Lehnen, Philip; Schinke, Thorsten; Yin, Na; Vomstein, Sandra; Amling, Michael; Schüle, Roland

    2005-01-01

    Osteoporosis is one of the major health problems today, yet little is known about the loss of bone mass caused by reduced activity of the bone-forming osteoblasts. Here we show that mice deficient for the transcriptional cofactor four and a half LIM domains 2 (Fhl2) exhibit a dramatic decrease of bone mass in both genders. Osteopenia is caused by a reduced bone formation rate that is solely due to the diminished activity of Fhl2-deficient osteoblasts, while their number remains unchanged. The number and activity of the bone-resorbing cells, the osteoclasts, is not altered. Enforced expression of Fhl2 in differentiated osteoblasts boosts mineralization in cell culture and, importantly, enhances bone formation in transgenic animals. Fhl2 increases the transcriptional activity of runt-related transcription factor 2 (Runx2), a key regulator of osteoblast function, and both proteins interact in vitro and in vivo. In summary, we present Fhl2-deficient mice as a unique model for osteopenia due to decreased osteoblast activity. Our data offer a novel concept to fight osteoporosis by modulating the anabolic activity of osteoblasts via Fhl2. PMID:16079911

  16. Solar Thermal Propulsion Investigation Activities in NAL

    NASA Astrophysics Data System (ADS)

    Sahara, Hironori; Shimizu, Morio

    2004-03-01

    We successfully developed the ultra-light single shell paraboloidal concentrators made of a sheet of aluminized or silvered polymer membrane, formed via plastic deformation due to stress relaxation under high temperature condition by means of Straight Formation Method. Furthermore, we improved the precision of the concentrators by taking the elastic deformation of residual stress into consideration, and obtained the best concentration performance equivalent to a highly precise paraboloidal glass mirror. In solar concentration, the diameter of solar focal image via the single shell polymer concentrator is almost equal to that via the glass mirror and they are twice as large as that of the theoretical. The ultra-light single shell polymer concentrators are very useful for the concentrator in solar thermal propulsion system and solar power station in particular, and also promising item for beamed energy propulsion.

  17. Preliminary Investigation of an Active PLZT Lens

    NASA Technical Reports Server (NTRS)

    Lightsey, W. D.; Peters, B. R.; Reardon, P. J.; Wong, J. K.

    2001-01-01

    The design, analysis and preliminary testing of a prototype Adjustable Focus Optical Correction Lens (AFOCL) is described. The AFOCL is an active optical component composed of solid state lead lanthanum-modified zirconate titanate (PLZT) ferroelectric ceramic with patterned indium tin oxide (ITO) transparent surface electrodes that modulate the refractive index of the PLZT to function as an electro-optic lens. The AFOCL was developed to perform optical re-alignment and wavefront correction to enhance the performance of Ultra-Lightweight Structures and Space Observatories (ULSSO). The AFOCL has potential application as an active optical component within a larger optical system. As such, information from a wavefront sensor would be processed to provide input to the AFOCL to drive the sensed wavefront to the desired shape and location. While offering variable and rapid focussing capability (controlled wavefront manipulation) similar to liquid crystal based spatial light modulators (SLM), the AFOCL offers some potential advantages because it is a solid-state, stationary, low-mass, rugged, and thin optical element that can produce wavefront quality comparable to the solid refractive lens it replaces. The AFOCL acts as a positive or negative lens by producing a parabolic phase-shift in the PLZT material through the application of a controlled voltage potential across the ITO electrodes. To demonstrate the technology, a 4 mm diameter lens was fabricated to produce 5-waves of optical power operating at 2.051 micrometer wavelength. Optical metrology was performed on the device to measure focal length, optical quality, and efficiency for a variety of test configurations. The data was analyzed and compared to theoretical data available from computer-based models of the AFOCL.

  18. AN ULTRAVIOLET INVESTIGATION OF ACTIVITY ON EXOPLANET HOST STARS

    SciTech Connect

    Shkolnik, Evgenya L.

    2013-03-20

    Using the far-UV (FUV) and near-UV (NUV) photometry from the NASA Galaxy Evolution Explorer (GALEX), we searched for evidence of increased stellar activity due to tidal and/or magnetic star-planet interactions (SPI) in the 272 known FGK planetary hosts observed by GALEX. With the increased sensitivity of GALEX, we are able probe systems with lower activity levels and at larger distances than what has been done to date with X-ray satellites. We compared samples of stars with close-in planets (a < 0.1 AU) to those with far-out planets (a > 0.5 AU) and looked for correlations of excess activity with other system parameters. This statistical investigation found no clear correlations with a, M{sub p} , or M{sub p} /a, in contrast to some X-ray and Ca II studies. However, there is tentative evidence (at a level of 1.8{sigma}) that stars with radial-velocity-(RV)-detected close-in planets are more FUV-active than stars with far-out planets, in agreement with several published X-ray and Ca II results. The case is strengthened to a level of significance to 2.3{sigma} when transit-detected close-in planets are included. This is most likely because the RV-selected sample of stars is significantly less active than the field population of comparable stars, while the transit-selected sample is similarly active. Given the factor of 2-3 scatter in fractional FUV luminosity for a given stellar effective temperature, it is necessary to conduct a time-resolved study of the planet hosts in order to better characterize their UV variability and generate a firmer statistical result.

  19. Gamma exposure rates due to neutron activation of soil: site of Hood detonation, Operation Plumbbob

    SciTech Connect

    Auxier, J.A.; Ohnesorge, W.F.

    1980-06-01

    This paper is the result of some recent discussions of exposure rates within the first few hours of the Hood detonation of the Plumbbob series due to neutron activation of soil. We estimated the exposure rates from 1/2 to 3 h after the detonation from ground zero to 1000 yards from ground zero. The area was assumed to be uncontaminated by fallout. Soil samples from the area of the Nevada Test Site at which the Hood device was detonated were sent to ORNL by Dr. John Malik of Los Alamos and by Mr. Gordon Jacks of the Nevada Test Site. These samples were irradiated at the DOSAR facility and the resulting activity analyzed. Calculations of exposure rates were then made based on the analyzed activity and the measured thermal neutron fluences at DOSAR and at the Hood Site.

  20. Out of control: Diminished prefrontal activity coincides with impaired motor performance due to choking under pressure

    PubMed Central

    Lee, Taraz G.; Grafton, Scott T.

    2014-01-01

    There are three non-exclusive theoretical explanations for the paradoxical collapse of performance due to large financial incentives. It has been proposed that “choking under pressure” is either due to distraction, interference via an increase in top-down control and performance monitoring, or excessive levels of arousal in the face of large losses. Given the known neural architecture involved in executive control and reward, we used fMRI of human participants during incentivized motor performance to provide evidence to support and/or reconcile these competing models in a visuomotor task. We show that the execution of a pre-trained motor task during neuroimaging is impaired by high rewards. BOLD activity occurring prior to movement onset is increased in dorsolateral prefrontal cortex and functional connectivity between this region and motor cortex is likewise increased just prior to choking. However, the extent of this increase in functional connectivity is inversely related to a participant's propensity to choke, suggesting that a failure in exerting top-down influence on motor control underlies choking under pressure due to large incentives. These results are consistent with a distraction account of choking and suggest that frontal influences on motor activity are necessary to protect performance from vulnerability under pressure. PMID:25449744

  1. Out of control: diminished prefrontal activity coincides with impaired motor performance due to choking under pressure.

    PubMed

    Lee, Taraz G; Grafton, Scott T

    2015-01-15

    There are three non-exclusive theoretical explanations for the paradoxical collapse of performance due to large financial incentives. It has been proposed that "choking under pressure" is either due to distraction, interference via an increase in top-down control and performance monitoring, or excessive levels of arousal in the face of large losses. Given the known neural architecture involved in executive control and reward, we used fMRI of human participants during incentivized motor performance to provide evidence to support and/or reconcile these competing models in a visuomotor task. We show that the execution of a pre-trained motor task during neuroimaging is impaired by high rewards. BOLD activity occurring prior to movement onset is increased in dorsolateral prefrontal cortex and functional connectivity between this region and motor cortex is likewise increased just prior to choking. However, the extent of this increase in functional connectivity is inversely related to a participant's propensity to choke, suggesting that a failure in exerting top-down influence on motor control underlies choking under pressure due to large incentives. These results are consistent with a distraction account of choking and suggest that frontal influences on motor activity are necessary to protect performance from vulnerability under pressure.

  2. Experimental response of Salix cuttings to different flow regimes due to human activities

    NASA Astrophysics Data System (ADS)

    Gorla, Lorenzo; Signarbieux, Constant; Turberg, Pascal; Buttler, Alexandre; Perona, Paolo

    2014-05-01

    Hydropower production and other human activities change the natural flow regime of rivers, in turn impacting the riparian environment. The main challenge in order to define eco-sustainable flows is to quantify the effects in terms of geomorphology and ecosystem adaptation. We present 2-years controlled experiments to investigate riparian vegetation (Salix Viminalis) response to forced water table changing dynamics, from one water regime to another, in a temperate region (Switzerland). Three synthetic flow regimes have been simulated and applied to three batteries of Salix cuttings growing outdoor within plastic pots, each about 1 meter tall. In 2012 one treatment simulated a minimal flow policy for small run-of-river hydropower plants, which drastically impacts the low and the medium-low components of the hydrograph, but not the extremes. In 2013 we confirmed and completed some of 2012 results, by reproducing typical hydropeaking effects due to dam management and focusing on daily water table variations and offsets. For both the seasons, after an initial period where all pots undergone the same oscillations in order to uniform the plants initial conditions, the experiment started, and the water dynamic was changed. Cuttings transitory response dynamics has been quantified by continuous sap flow and water potential measurements, and by regularly collecting growth parameters, as well as leaves photosynthesis, fluorescence, and pictures of each plant. At the end of the experiment, all cuttings were carefully removed and the both above and below ground biomass analyzed in detail. Particularly, the 3D root structure was obtained by High Resolution Computer Tomography. Our analyses revealed a clear dependence between roots distribution and water regime reflecting the need for adaptation, in agreement with field observations of Pasquale et al. (2012). In particular, an initial strong difference in terms of stress and growth performances was then followed by a later

  3. Changes in Mice Brain Spontaneous Electrical Activity during Cortical Spreading Depression due to Mobile Phone Radiation

    PubMed Central

    Sallam, Samera M.; Mohamed, Ehab I.; Dawood, Abdel-Fattah B.

    2008-01-01

    The objective of the present study was to investigate changes in spontaneous EEG activity during cortical spreading depression (CSD) in mice brain. The cortical region of anaesthetized mice were exposed to the electromagnetic fields (EMFs) emitted from a mobile phone (MP, 935.2-960.2 MHz, 41.8 mW/cm2). The effect of EMFs on EEG was investigated before and after exposure to different stimuli (MP, 2% KCl, and MP & 2% KCl). The records of brain spontaneous EEG activity, slow potential changes (SPC), and spindle shaped firings were obtained through an interfaced computer. The results showed increases in the amplitude of evoked spindles by about 87%, 17%, and 226% for MP, 2% KCl, and MP & 2% KCl; respectively, as compared to values for the control group. These results showed that the evoked spindle is a more sensitive indicator of the effect of exposure to EMFs from MP. PMID:23675079

  4. Infra red active modes due to coupling of cyclotron excitation and LO phonons in polar semiconductor

    NASA Astrophysics Data System (ADS)

    Agrawal, Ratna; Dubey, Swati; Ghosh, S.

    2013-06-01

    Effects of free carrier concentration, external magnetic field and Callen effective charge on infra red active modes in a polar semiconductor have been analytically investigated using simple harmonic oscillator model. Callen effective charge considerably enhances reflectivity and shifts minima towards lower values of energy. Presence of magnetic field leads towards the coupling of collective cyclotron excitations with LO phonon giving rise to maximum reflectivity whereas cyclotron resonance absorption results into minimum reflectivity.

  5. Hypersomnia due to injury of the ventral ascending reticular activating system following cerebellar herniation

    PubMed Central

    Jang, Sung Ho; Chang, Chul Hoon; Jung, Young Jin; Kwon, Hyeok Gyu

    2017-01-01

    Abstract Rationale: We report on a patient with hypersomnia who showed injury of the lower ascending reticular activating system (ARAS) following cerebellar herniation due to a cerebellar infarct, detected on diffusion tensor tractography (DTT). Patient concerns: A 53-year-old male patient was diagnosed as a left cerebellar infarct, and underwent decompressive suboccipital craniectomy due to brain edema at 2 days after the onset of a cerebellar infarct. Three weeks after onset when the patient started rehabilitation, he showed hypersomnia without impairment of consciousness; he fell asleep most of daytime without external stimulation and showed an abnormal score on the Epworth Sleepiness Scale: 15 (full score: 24, cut off for hypersomnia: 10). Diagnoses and Outcomes: On 3-week DTT, narrowing of the upper portion of the lower ventral ARAS between the pontine reticular formation and the hypothalamus was observed on both sides. In addition, partial tearing was observed in the middle portion of the right lower ventral ARAS. Lessons: In conclusion, we found injury of the lower ventral ARAS in a patient with hypersomnia following cerebellar herniation due to a cerebellar infarct. PMID:28072702

  6. CALCULATING ENERGY STORAGE DUE TO TOPOLOGICAL CHANGES IN EMERGING ACTIVE REGION NOAA AR 11112

    SciTech Connect

    Tarr, Lucas; Longcope, Dana

    2012-04-10

    The minimum current corona model provides a way to estimate stored coronal energy using the number of field lines connecting regions of positive and negative photospheric flux. This information is quantified by the net flux connecting pairs of opposing regions in a connectivity matrix. Changes in the coronal magnetic field, due to processes such as magnetic reconnection, manifest themselves as changes in the connectivity matrix. However, the connectivity matrix will also change when flux sources emerge or submerge through the photosphere, as often happens in active regions. We have developed an algorithm to estimate the changes in flux due to emergence and submergence of magnetic flux sources. These estimated changes must be accounted for in order to quantify storage and release of magnetic energy in the corona. To perform this calculation over extended periods of time, we must additionally have a consistently labeled connectivity matrix over the entire observational time span. We have therefore developed an automated tracking algorithm to generate a consistent connectivity matrix as the photospheric source regions evolve over time. We have applied this method to NOAA Active Region 11112, which underwent a GOES M2.9 class flare around 19:00 on 2010 October 16th, and calculated a lower bound on the free magnetic energy buildup of {approx}8.25 Multiplication-Sign 10{sup 30} erg over 3 days.

  7. Activation of Graphenic Carbon Due to Substitutional Doping by Nitrogen: Mechanistic Understanding from First Principles.

    PubMed

    Bhattacharjee, Joydeep

    2015-05-07

    Nitrogen-doped graphene and carbon nanotubes are popularly in focus as metal-free electrocatalysts for oxygen reduction reactions (ORR) central to fuel cells. N-doped CNTs have been also reported to chemisorb mutually, promising a route to their robust predetermined assembly into devices and mechanical reinforcements. We propose from first principles a common mechanistic understanding of these two aspects pointing further to a generic chemical activation of carbon atoms due to substitution by nitrogen in experimentally observed configurations. Wannier-function based orbital resolved study of mechanisms suggests increase in C-N bond-orders in attempt to retain π-conjugation among carbon atoms, causing mechanical stress and loss of charge neutrality of nitrogen and carbon atoms, which remedially facilitate chemical activation of N-coordinated C atoms, enhancing sharply with increasing coordination to N and proximity to zigzag edges. Activated C atoms facilitate covalent adsorption of radicals in general, diradicals like O2 relevant to ORR, and also other similarly activated C atoms, leading to self-assembly of graphenic nanostructures while remaining inert to ordinary graphenic C atoms.

  8. RADIOLOGICAL RELEASES DUE TO AIR AND SILICA DUST ACTIVATION IN EMPLACEMENT DRIFTS

    SciTech Connect

    J.S. Tang

    2003-05-07

    The purpose of this calculation is to determine the quantity and significance of annual Monitored Geologic Repository (MGR) subsurface normal radiological releases due to neutron activation of air and silica dust in emplacement drifts. This calculation includes the following items: (1) Calculate activation of ventilation airflow through emplacement drifts to quantify radioactive gaseous releases; and (2) Calculate the bounding potential activated silica dust concentration and releases. The sources of silica dust may arise from air supply to emplacement drifts as well as host rock around emplacement drifts. For this calculation, the source of dust is conservatively assumed to be the host rock (Assumption 3.6), which is subject to long-term neutron exposure resulting in saturated radioactivity. The scope of this calculation is limited to releases from activated air and silica dust only, excluding natural radioactive releases such as radon or releases from defective waste packages (breached or contaminated). This work supports the repository ventilation system design and Preclosure Safety Analysis. This includes MGR items classified as Quality Level 1, for example, the Uncanistered Spent Nuclear Fuel Waste Package (CRWMS M&O [Civilian Radioactive Waste Management and Operation Contractor] 1999a, page 7). Therefore, this calculation is subject to the requirements of the ''Quality Assurance Requirements and Description'' (DOE [U.S. Department of Energy] 2003). The performance of the calculation and development of this document are carried out in accordance with AP-3.12Q, ''Design Calculation and Analyses'' and LP-3.30Q-BSC, ''Hazards Analysis System''.

  9. Absence of Remote Triggering in Geothermal Fields Due to Human Activity

    NASA Astrophysics Data System (ADS)

    Ge, S.; Zhang, Q.; Lin, G.

    2014-12-01

    Operational geothermal fields typically have high seismicity rates, which could be caused by both tectonic and anthropogenic activities. Due to the high background seismicity and possible interaction between fluid and seismic waves, geothermal areas have been recognized to be susceptible to large remote earthquakes. However, whether human activity (geothermal production) affects remote earthquake triggering by changing the stress state is unclear. Here we choose two geothermal fields, Coso and Salton Sea in southern California, to study the spatiotemporal distributions of the triggered earthquakes following the 1992 Mw 7.3 Landers and 1999 Mw 7.1 Hector Mine earthquakes. These two geothermal fields have been in operation since 1980s with comparable net capacity, and have long-term geothermal fluid loss. By analyzing the regional catalog recorded by the Southern California Seismic Network, we find that these two operational geothermal areas remain unaffected by the remote mainshocks, whereas the surrounding areas show vigorous triggered responses. We interpret this phenomenon as a result of human activity, which presumably has brought the stress state away from failure by reducing pore pressure. To further understand how much the human activity can affect the stress state, we also conduct a systematic study on Long Valley Caldera in northern California as a comparison site. Long Valley Caldera hosts an active geothermal field with net capacity about one sixth of that in Coso or Salton Sea geothermal field, and the extraction volume is not constantly larger than the injection. We will show comparisons of the triggered response in Long Valley with the two geothermal fields in southern California.

  10. Variations of 14C around AD 775 and AD 1795 - due to solar activity

    NASA Astrophysics Data System (ADS)

    Neuhäuser, R.; Neuhäuser, D. L.

    2015-12-01

    The motivation for our study is the disputed cause for the strong variation of 14C around AD 775. Our method is to compare the 14C variation around AD 775 with other periods of strong variability. Our results are: (a) We see three periods, where 14C varied over 200 yr in a special way showing a certain pattern of strong secular variation: after a Grand Minimum with strongly increasing 14C, there is a series of strong short-term drop(s), rise(s), and again drop(s) within 60 yr, ending up to 200 yr after the start of the Grand Minimum. These three periods include the strong rises around BC 671, AD 775, and AD 1795. (b) We show with several solar activity proxies (radioisotopes, sunspots, and aurorae) for the AD 770s and 1790s that such intense rapid 14C increases can be explained by strong rapid decreases in solar activity and, hence, wind, so that the decrease in solar modulation potential leads to an increase in radioisotope production. (c) The strong rises around AD 775 and 1795 are due to three effects, (i) very strong activity in the previous cycles (i.e. very low 14C level), (ii) the declining phase of a very strong Schwabe cycle, and (iii) a phase of very weak activity after the strong 14C rise - very short and/or weak cycle(s) like the suddenly starting Dalton minimum. (d) Furthermore, we can show that the strong change at AD 1795 happened after a pair of two packages of four Schwabe cycles with certain hemispheric leadership (each package consists of two Gnevyshev-Ohl pairs, respectively two Hale-Babcock pairs). We show with several additional arguments that the rise around AD 775 was not that special. We conclude that such large, short-term rises in 14C (around BC 671, AD 775, and 1795) do not need to be explained by highly unlikely solar super-flares nor other rare events, but by extra-solar cosmic rays modulated due to solar activity variations.

  11. Estriol-induced fibrinolysis due to the activation of plasminogen to plasmin by nitric oxide synthesis in platelets.

    PubMed

    Jana, Pradipta; Maiti, Smarajit; Kahn, Nighat N; Sinha, Asru K

    2015-04-01

    Estriol, an oestrogen, at 0.6 nmol/l was reported to inhibit ADP-induced platelet aggregation through nitric oxide synthesis. As nitric oxide has been reported to cause fibrinolysis due to the activation of plasminogen to plasmin, the role of estriol as a fibrinolytic agent was investigated. Also, the mechanism of estriol-induced nitric oxide synthesis in anucleated platelets was investigated. The estriol-induced lysis of platelet-rich plasma (PRP) clot was determined by photography of the clot lysis and by the assay of fibrin degradation products in the lysate and was obtained by SDS-PAGE. Nitric oxide was determined by methemoglobin method. The platelet membrane protein was isolated from the platelets by using Triton X-100 (0.05% v/v). The binding of estriol to the protein was determined by Scatchard plot by using an ELISA for estriol. Estriol at 0.6 nmol/l was found to lyse the clotted PRP due to fibrinolysis that produced fibrin degradation products in the lysate. The amino acid analysis of the platelet membrane protein, which resembles with nitric oxide synthase (NOS) activity, was activated nearly 10-fold over the control in the presence of estriol and was identified to be a human serum albumin precursor (Mr. 69 kDa) that binds to estriol with Kd1 of 6.0 × 10 mol/l and 39 ± 2 molecules of estriol bound the NOS molecule. The estriol-induced nitric oxide is capable of inducing fibrinolysis of the clotted PRP. The binding of estriol to platelet membrane NOS activated the enzyme in the absence of DNA in the platelet.

  12. Reduction method of DBTT shift due to irradiation for reduced-activation ferritic/martensitic steels

    NASA Astrophysics Data System (ADS)

    Wakai, E.; Okubo, N.; Ando, M.; Yamamoto, T.; Takada, F.

    2010-03-01

    The method for reducing irradiation-induced DBTT shift of reduced-activation ferritic/martensitic steels was examined. F82H-LN (low nitrogen, 20 ppm), F82H+60 ppm 11B+200 ppmN and F82H+60 ppm 10B+200 ppmN steels tempered at 780 °C for 0.5 h were irradiated at 250 °C to 2 dpa, and the results for Charpy impact tests were analyzed. The upper shelf energy of F82H+ 11B+N steel was hardly changed by the irradiation, and DBTT shift was very small. From our research, DBTT shift due to irradiation can be reduced by the control of tempered conditions before irradiation, and it is found to be furthermore reduced by impurity doping with 60 ppm 11B and 200 ppmN to F82H steel.

  13. Enhanced antioxidant defense due to extracellular catalase activity in Syrian hamster during arousal from hibernation.

    PubMed

    Ohta, Hitomi; Okamoto, Iwao; Hanaya, Toshiharu; Arai, Shigeyuki; Ohta, Tsunetaka; Fukuda, Shigeharu

    2006-08-01

    Mammalian hibernators are considered a natural model for resistance to ischemia-reperfusion injuries, and protective mechanisms against oxidative stress evoked by repeated hibernation-arousal cycles in these animals are increasingly the focus of experimental investigation. Here we show that extracellular catalase activity provides protection against oxidative stress during arousal from hibernation in Syrian hamster. To examine the serum antioxidant defense system, we first assessed the hibernation-arousal state-dependent change in serum attenuation of cytotoxicity induced by hydrogen peroxide. Serum obtained from hamsters during arousal from hibernation at a rectal temperature of 32 degrees C, concomitant with the period of increased oxidative stress, attenuated the cytotoxicity four-fold more effectively than serum from cenothermic control hamsters. Serum catalase activity significantly increased during arousal, whereas glutathione peroxidase activity decreased by 50%, compared with cenothermic controls. The cytoprotective effect of purified catalase at the concentration found in serum was also confirmed in a hydrogen peroxide-induced cytotoxicity model. Moreover, inhibition of catalase by aminotriazole led to an 80% loss of serum hydrogen peroxide scavenging activity. These results suggest that extracellular catalase is effective for protecting hibernators from oxidative stress evoked by arousal from hibernation.

  14. Changes in antibacterial activity of triclosan and sulfa drugs due to photochemical transformations.

    PubMed

    Wammer, Kristine H; Lapara, Timothy M; McNeill, Kristopher; Arnold, William A; Swackhamer, Deborah L

    2006-06-01

    Sulfa drugs and triclosan represent two classes of antibacterials that have been found in natural waters and for which photodegradation is anticipated to be a significant loss process. Parent antibacterial compounds and the products of photolysis reactions were compared for three sulfa drugs and triclosan to determine the extent to which photolysis affects their antibacterial potency on Escherichia coli DH5alpha. Sulfathiazole (median effective concentration [EC50] = 20.0 microM), sulfamethoxazole (EC50 = 12.3 microM), and sulfachloropyridazine (EC50 = 6.9 microM) inhibited bacterial growth but did not affect respiratory activity. Photolysis products of these sulfa drugs did not retain any measurable ability to inhibit growth. Triclosan inhibited both the growth (EC50 = 0.24 microM) and respiratory activity of E. coli DH5alpha. Triclosan photolysis products also exhibited no measurable effect on growth or respiratory activity. These experiments indicate that the products of triclosan and sulfa drug photolysis are unlikely to possess antibacterial activity in natural waters. The rapid screening method used for these two classes of compounds will be useful for helping to identify photolabile antibacterial compounds, for which photoproducts could require further investigation.

  15. Undesirable Consequences of Insecticide Resistance following Aedes aegypti Control Activities Due to a Dengue Outbreak

    PubMed Central

    Maciel-de-Freitas, Rafael; Avendanho, Fernando Campos; Santos, Rosangela; Sylvestre, Gabriel; Araújo, Simone Costa; Lima, José Bento Pereira; Martins, Ademir Jesus; Coelho, Giovanini Evelim; Valle, Denise

    2014-01-01

    Background During a dengue outbreak with co-circulation of DENV-1 and -2 in the city of Boa Vista, one patient was diagnosed with DENV-4, a serotype supposed absent from Brazil for almost 30 years. The re-emergence of DENV-4 triggered the intensification of mechanical and chemical Aedes aegypti control activities in order to reduce vector density and avoid DENV-4 dissemination throughout the country. Methods/Principal Findings Vector control activities consisted of (a) source reduction, (b) application of diflubenzuron against larvae and (c) vehicle-mounted space spraying of 2% deltamethrin to eliminate adults. Control activity efficacy was monitored by comparing the infestation levels and the number of eggs collected in ovitraps before and after interventions, performed in 22 Boa Vista districts, covering an area of ∼80% of the city and encompassing 56,837 dwellings. A total of 94,325 containers were eliminated or treated with diflubenzuron. The most frequently positive containers were small miscellaneous receptacles, which corresponded to 59% of all positive breeding sites. Insecticide resistance to deltamethrin was assessed before, during and after interventions by dose-response bioassays adopting WHO-based protocols. The intense use of the pyrethroid increased fourfold the resistance ratio of the local Ae. aegypti population only six months after the beginning of vector control. Curiously, this trend was also observed in the districts in which no deltamethrin was applied by the public health services. On the other hand, changes in the resistance ratio to the organophosphate temephos seemed less influenced by insecticide in Boa Vista. Conclusions Despite the intense effort, mosquito infestation levels were only slightly reduced. Besides, the median number of eggs in ovitraps remained unaltered after control activity intensification. The great and rapid increase in pyrethroid resistance levels of natural Ae. aegypti populations is discussed in the context of

  16. Persistent hydrocephalus due to postural activation of a ventricular shunt anti-gravity device.

    PubMed

    Craven, Claudia L; Toma, Ahmed K; Watkins, Laurence D

    2017-03-01

    The ever present need to balance over drainage with under drainage in hydrocephalus has required innovations including adjustable valves with antigravity devices. These are activated in the vertical position to prevent siphoning. We describe a group of bedridden patients who presented with unexplained under drainage caused by activation of antigravity shunt components produced by peculiar head/body position. Retrospective single centre case series of hydrocephalus patients, treated with ventriculo-peritoneal (VP) shunt insertion between April 2014 - February 2016. These patients presented with clinical and radiological under drainage syndrome. Medical notes were reviewed for clinical picture and outcome. Radiological studies were reviewed assessing shunt placement and ventricular size. Seven patients presented with clinical and radiological under drainage syndrome. A consistent posturing of long term hyper-flexion of the neck whilst lying supine was observed. All patients had similar shunt construct (adjustable Miethke ProGAV valve and shunt assistant anti-gravity component). In each of those patients a hypothesis was formulated that neck flexion was activating the shunt assistance anti-gravity component in supine position. Five patients underwent shunt revision surgery removing the shunt assistant device from the cranium and adding an anti-gravity component to the shunt system at the chest. One had the shunt assistant completely removed and one patient was managed conservatively with mobilisation. All patients had clinical and radiological improvement. Antigravity shunt components implanted cranially in bedridden hydrocephalus patients will produce underdrainage due to head flexion induced anti-gravity device activation. In these patients, anti-gravity devices should be placed at the chest. Alternatively, special nursing attention should be paid to head-trunk angle.

  17. Exacerbated cardiac fibrosis induced by β-adrenergic activation in old mice due to decreased AMPK activity.

    PubMed

    Wang, Jingjing; Song, Yao; Li, Hao; Shen, Qiang; Shen, Jing; An, Xiangbo; Wu, Jimin; Zhang, Jianshu; Wu, Yunong; Xiao, Han; Zhang, Youyi

    2016-11-01

    Senescent hearts exhibit defective responses to β-adrenergic receptor (β-AR) over-activation upon stress, leading to more severe pathological cardiac remodelling. However, the underlying mechanisms remain unclear. Here, we investigated the role of adenosine monophosphate-activated protein kinase (AMPK) in protecting against ageing-associated cardiac remodelling in mice upon β-AR over-activation. 10-week-old (young) and 18-month-old (old) mice were subcutaneously injected with the β-AR agonist isoproterenol (ISO; 5 mg/kg). More extensive cardiac fibrosis was found in old mice upon ISO exposure than in young mice. Meanwhile, ISO treatment decreased AMPK activity and increased β-arrestin 1, but not β-arrestin 2, expression, and the effects of ISO on AMPK and β-arrestin 1 were greater in old mice than in young mice. Similarly, young AMPKα2-knockout (KO) mice showed more extensive cardiac fibrosis upon ISO exposure than that was observed in age-matched wild-type (WT) littermates. The extent of cardiac fibrosis in WT old mice was similar to that in young KO mice. Additionally, AMPK activities were decreased and β-arrestin 1 expression increased in KO mice. In contrast, the AMPK activator metformin decreased β-arrestin 1 expression and attenuated cardiac fibrosis in both young and old mice upon ISO exposure. In conclusion, more severe cardiac fibrosis is induced by ISO in old mice than in young mice. A decrease in AMPK activity, which further increases β-arrestin 1 expression, is the central mechanism underlying the ageing-related cardiac fibrosis induced by ISO. The AMPK activator metformin is a promising therapeutic agent for treating ageing-related cardiac remodelling upon β-AR over-activation.

  18. Investigating the Impacts of Surface Temperature Anomalies due to Burned Area Albedo in Northern sub-Saharan Africa

    NASA Astrophysics Data System (ADS)

    Gabbert, T.; Matsui, T.; Capehart, W. J.; Ichoku, C. M.; Gatebe, C. K.

    2015-12-01

    The northern Sub-Saharan African region (NSSA) is an area of intense focus due to periodic severe droughts that have dire consequences on the growing population, which relies mostly on rain fed agriculture for its food supply. This region's weather and hydrologic cycle are very complex and are dependent on the West African Monsoon. Different regional processes affect the West African Monsoon cycle and variability. One of the areas of current investigation is the water cycle response to the variability of land surface characteristics. Land surface characteristics are often altered in NSSA due to agricultural practices, grazing, and the fires that occur during the dry season. To better understand the effects of biomass burning on the hydrologic cycle of the sub-Saharan environment, an interdisciplinary team sponsored by NASA is analyzing potential feedback mechanisms due to the fires. As part of this research, this study focuses on the effects of land surface changes, particularly albedo and skin temperature, that are influenced by biomass burning. Surface temperature anomalies can influence the initiation of convective rainfall and surface albedo is linked to the absorption of solar radiation. To capture the effects of fire perturbations on the land surface, NASA's Unified Weather and Research Forecasting (NU-WRF) model coupled with NASA's Land Information System (LIS) is being used to simulate burned area surface albedo inducing surface temperature anomalies and other potential effects to environmental processes. Preliminary sensitivity results suggest an altered surface radiation budget, regional warming of the surface temperature, slight increase in average rainfall, and a change in precipitation locations.

  19. Dynamic instability of cooperation due to diverse activity patterns in evolutionary social dilemmas

    NASA Astrophysics Data System (ADS)

    Xia, Cheng-Yi; Meloni, Sandro; Perc, Matjaž; Moreno, Yamir

    2015-03-01

    Individuals might abstain from participating in an instance of an evolutionary game for various reasons, ranging from lack of interest to risk aversion. In order to understand the consequences of such diverse activity patterns on the evolution of cooperation, we study a weak prisoner's dilemma where each player's participation is probabilistic rather than certain. Players that do not participate get a null payoff and are unable to replicate. We show that inactivity introduces cascading failures of cooperation, which are particularly severe on scale-free networks with frequently inactive hubs. The drops in the fraction of cooperators are sudden, while the spatiotemporal reorganization of compact cooperative clusters, and thus the recovery, takes time. Nevertheless, if the activity of players is directly proportional to their degree, or if the interaction network is not strongly heterogeneous, the overall evolution of cooperation is not impaired. This is because inactivity negatively affects the potency of low-degree defectors, who are hence unable to utilize on their inherent evolutionary advantage. Between cascading failures, the fraction of cooperators is therefore higher than usual, which lastly balances out the asymmetric dynamic instabilities that emerge due to intermittent blackouts of cooperative hubs.

  20. The nucleoporin Nup153 affects spindle checkpoint activity due to an association with Mad1

    PubMed Central

    Shimi, Takeshi

    2010-01-01

    The nucleoporin Nup153 is known to play pivotal roles in nuclear import and export in interphase cells and as the cell transitions into mitosis, Nup153 is involved in nuclear envelope breakdown. In this study, we demonstrate that the interaction of Nup153 with the spindle assembly checkpoint protein Mad1 is important in the regulation of the spindle checkpoint. Overexpression of human Nup153 in HeLa cells leads to the appearance of multinucleated cells and induces the formation of multipolar spindles. Importantly, it causes inactivation of the spindle checkpoint due to hypophosphorylation of Mad1. Depletion of Nup153 using RNA interference results in the decline of Mad1 at nuclear pores during interphase and more significantly causes a delayed dissociation of Mad1 from kinetochores in metaphase and an increase in the number of unresolved midbodies. In the absence of Nup153 the spindle checkpoint remains active. In vitro studies indicate direct binding of Mad1 to the N-terminal domain of Nup153. Importantly, Nup153 binding to Mad1 affects Mad1's phosphorylation status, but not its ability to interact with Mad2. Our data suggest that Nup153 levels regulate the localization of Mad1 during the metaphase/anaphase transition thereby affecting its phoshorylation status and in turn spindle checkpoint activity and mitotic exit. PMID:21327106

  1. Whiting events: biogenic origin due to the photosynthetic activity of cyanobacterial picoplankton

    NASA Technical Reports Server (NTRS)

    Thompson, J. B.; Schultze-Lam, S.; Beveridge, T. J.; Des Marais, D. J.

    1997-01-01

    An annual whiting event occurs each year in late May to early June in Fayetteville Green Lake, New York. The initiation of this event correlates with exponential growth of the Synechococcus population within the lake. Synechococcus is the dominant (by approximately 4 orders of magnitude) autotrophic organism owing to the oligotrophic condition of the lake. The delta 13C values of the dissolved inorganic C range seasonally from -9.5% in winter to -6.2% in summer due to photosynthetic activity. Calcite precipitates principally in the microenvironment surrounding Synechococcus because of a photosynthetically driven alkalization process and the availability of the cells as nucleation sites. This calcite has a heavier delta 13C value (>4%) than does the dissolved inorganic C of the lake water owing to the cells' preferential uptake of 12C. A conceptual model suggests that photosynthetic activity and cell surface chemistry, together with the substantial surface area that arises from the great abundance of micron-sized cells, allow Synechococcus to dominate the annual whiting events in Fayetteville Green Lake.

  2. MELANOPHORE BANDS AND AREAS DUE TO NERVE CUTTING, IN RELATION TO THE PROTRACTED ACTIVITY OF NERVES

    PubMed Central

    Parker, G. H.

    1941-01-01

    1. When appropriate chromatic nerves are cut caudal bands, cephalic areas, and the pelvic fins of the catfish Ameiurus darken. In pale fishes all these areas will sooner or later blanch. By recutting their nerves all such blanched areas will darken again. 2. These observations show that the darkening of caudal bands, areas, and fins on cutting their nerves is not due to paralysis (Brücke), to the obstruction of central influences such as inhibition (Zoond and Eyre), nor to vasomotor disturbances (Hogben), but to activities emanating from the cut itself. 3. The chief agents concerned with the color changes in Ameiurus are three: intermedin from the pituitary gland, acetylcholine from the dispersing nerves (cholinergic fibers), and adrenalin from the concentrating nerves (adrenergic fibers). The first two darken the fish; the third blanches it. In darkening the dispersing nerves appear to initiate the process and to be followed and substantially supplemented by intermedin. 4. Caudal bands blanch by lateral invasion, cephalic areas by lateral invasion and internal disintegration, and pelvic fins by a uniform process of general loss of tint equivalent to internal disintegration. 5. Adrenalin may be carried in such an oil as olive oil and may therefore act as a lipohumor; it is soluble in water and hence may act as a hydrohumor. In lateral invasion (caudal bands, cephalic areas) it probably acts as a lipohumor and in internal disintegration (cephalic areas, pelvic fins) it probably plays the part of a hydrohumor. 6. The duration of the activity of dispersing nerves after they had been cut was tested by means of the oscillograph, by anesthetizing blocks, and by cold-blocks. The nerves of Ameiurus proved to be unsatisfactory for oscillograph tests. An anesthetizing block, magnesium sulfate, is only partly satisfactory. A cold-block, 0°C., is successful to a limited degree. 7. By means of a cold-block it can be shown that dispersing autonomic nerve fibers in Ameiurus can

  3. Physiological evidence that the 'interphase' in the formalin test is due to active inhibition.

    PubMed

    Henry, J L; Yashpal, K; Pitcher, G M; Coderre, T J

    1999-07-01

    Injection of a dilute solution of formalin into a rat hindpaw produces a biphasic nociceptive response consisting of an early phase during the first 5 min after formalin injection and a later phase starting after 15 min and lasting for 40-50 min. The period between the two phases of nociceptive responding is generally considered to be a phase of inactivity. We compared the nociceptive behaviors produced by a single hindpaw injection of 50 microl of formalin with those produced by two formalin injections given 20 min apart. A single formalin injection at concentrations of either 1 or 2.5%, produced the typical biphasic nociceptive responses. In rats given a second injection of either 1 or 2.5% formalin 20 min after the first, a triphasic response occurred, with a second diminution of nociceptive behavior observed between 10 and 15 min after the second injection. When a second injection of 2.5% formalin was given 5 min after the first, there was no difference from the scores in the group given only one injection. In electrophysiological experiments on single dorsal horn nociceptive neurons, a second injection of 2.5% formalin into the peripheral cutaneous receptive field, 40 min after the first and at the same site of injection as the first formalin injection, depressed neuronal activity for approximately 15-20 min. From the data it can be concluded that the interphase period in the formalin test is due to active inhibition. Furthermore, the inhibition which we are reporting here is independent of the concentration of formalin used, and thus of any so-called inflammatory component. The lack of additive nociceptive effects when the inter-injection interval was only 5 min, suggests that a maximum inhibition was provoked by 2.5% formalin; it can also be concluded that the active inhibition is of overriding importance physiologically, compared with the nociceptive activity. Data from parallel electrophysiological experiments on spinal dorsal horn neurons demonstrated a

  4. IMPLICATIONS OF MASS AND ENERGY LOSS DUE TO CORONAL MASS EJECTIONS ON MAGNETICALLY ACTIVE STARS

    SciTech Connect

    Drake, Jeremy J.; Cohen, Ofer; Yashiro, Seiji; Gopalswamy, Nat

    2013-02-20

    Analysis of a database of solar coronal mass ejections (CMEs) and associated flares over the period 1996-2007 finds well-behaved power-law relationships between the 1-8 A flare X-ray fluence and CME mass and kinetic energy. We extrapolate these relationships to lower and higher flare energies to estimate the mass and energy loss due to CMEs from stellar coronae, assuming that the observed X-ray emission of the latter is dominated by flares with a frequency as a function of energy dn/dE = kE {sup -{alpha}}. For solar-like stars at saturated levels of X-ray activity, the implied losses depend fairly weakly on the assumed value of {alpha} and are very large: M-dot {approx}5 Multiplication-Sign 10{sup -10} M{sub sun} yr{sup -1} and E-dot {approx}0.1 L{sub sun}. In order to avoid such large energy requirements, either the relationships between CME mass and speed and flare energy must flatten for X-ray fluence {approx}> 10{sup 31} erg, or the flare-CME association must drop significantly below 1 for more energetic events. If active coronae are dominated by flares, then the total coronal energy budget is likely to be up to an order of magnitude larger than the canonical 10{sup -3} L {sub bol} X-ray saturation threshold. This raises the question of what is the maximum energy a magnetic dynamo can extract from a star? For an energy budget of 1% of L {sub bol}, the CME mass loss rate is about 5 Multiplication-Sign 10{sup -11} M {sub Sun} yr{sup -1}.

  5. Telmisartan prevented cognitive decline partly due to PPAR-{gamma} activation

    SciTech Connect

    Mogi, Masaki; Li Jianmei; Tsukuda, Kana; Iwanami, Jun; Min, Li-Juan; Sakata, Akiko; Fujita, Teppei; Iwai, Masaru; Horiuchi, Masatsugu

    2008-10-24

    Telmisartan is a unique angiotensin receptor blocker (ARB) and partial agonist of peroxisome proliferator-activated receptor (PPAR)-{gamma}. Here, we investigated the preventive effect of telmisartan on cognitive decline in Alzheimer disease. In ddY mice, intracerebroventricular injection of A{beta} 1-40 significantly attenuated their cognitive function evaluated by shuttle avoidance test. Pretreatment with a non-hypotensive dose of telmisartan significantly inhibited such cognitive decline. Interestingly, co-treatment with GW9662, a PPAR-{gamma} antagonist, partially inhibited this improvement of cognitive decline. Another ARB, losartan, which has less PPAR-{gamma} agonistic effect, also inhibited A{beta}-injection-induced cognitive decline; however the effect was smaller than that of telmisartan and was not affected by GW9662. Immunohistochemical staining for A{beta} showed the reduced A{beta} deposition in telmisartan-treated mice. However, this reduction was not observed in mice co-administered GW9662. These findings suggest that ARB has a preventive effect on cognitive impairment in Alzheimer disease, and telmisartan, with PPAR-{gamma} activation, could exert a stronger effect.

  6. The influence of hepatic insufficiency due to alcoholic cirrhosis on the erythrocyte transketolase activity (ETKA).

    PubMed

    Graudal, N; Torp-Pedersen, K; Bonde, J; Hanel, H K; Kristensen, M; Milman, N; Thomsen, A C

    1987-04-01

    The erythrocyte transketolase activity (ETKA), the stimulated erythrocyte transketolase activity (ETKAS), and the thiaminepyrophosphate effect (TPPE) were measured in 21 alcoholic patients with cirrhosis and hepatic insufficiency, 13 alcoholic patients without cirrhosis and 21 non-alcoholic persons before and after oral treatment with 100 mg of thiamine daily for 2 weeks in order to investigate the influence of hepatic insufficiency on these variables. A statistically significant rise in ETKA and fall in TPPE were found in all three groups. ETKA, ETKAS and TPPE did not differ from each other in alcoholic patients with and without cirrhosis, but TPPE was significantly higher in these patients than in the non-alcoholic persons. The conclusions are that severe cirrhosis does not affect the erythrocyte transketolase apoenzyme, the ability of the tissues to convert thiamine to thiaminepyrophosphate for use in the erythrocytes or the absorption of thiamine from the gastrointestinal tract. Besides alcoholism seems to dispose to thiamine deficiency to a higher degree than cirrhosis, and the role of the liver as a thiamine store appears to be of minor importance in the development of thiamine deficiency. Finally, ETKA, ETKAS, and TPPE are considered to be usable as thiamine deficiency indicators in patients with cirrhosis as well as in patients without cirrhosis.

  7. Coal mining activities change plant community structure due to air pollution and soil degradation.

    PubMed

    Pandey, Bhanu; Agrawal, Madhoolika; Singh, Siddharth

    2014-10-01

    The aim of this study was to investigate the effects of coal mining activities on the community structures of woody and herbaceous plants. The response of individual plants of community to defilement caused by coal mining was also assessed. Air monitoring, soil physico-chemical and phytosociological analyses were carried around Jharia coalfield (JCF) and Raniganj coalfield. The importance value index of sensitive species minified and those of tolerant species enhanced with increasing pollution load and altered soil quality around coal mining areas. Although the species richness of woody and herbaceous plants decreased with higher pollution load, a large number of species acclimatized to the stress caused by the coal mining activities. Woody plant community at JCF was more affected by coal mining than herbaceous community. Canonical correspondence analysis revealed that structure of herbaceous community was mainly driven by soil total organic carbon, soil nitrogen, whereas woody layer community was influenced by sulphur dioxide in ambient air, soil sulphate and soil phosphorus. The changes in species diversity observed at mining areas indicated an increase in the proportion of resistant herbs and grasses showing a tendency towards a definite selection strategy of ecosystem in response to air pollution and altered soil characteristics.

  8. Aerosol nucleation and growth in the TTL, due to tropical convection, during the ACTIVE campaign

    NASA Astrophysics Data System (ADS)

    Waddicor, D.; Vaughan, G.; Choularton, T.

    2009-04-01

    The Aerosol and Chemical Transport In tropical convection (ACTIVE) campaign took place between October 2005 and February 2006. This investigation involved the sampling of deep convective storms that occur in the Tropics; the campaign was based in Darwin, Northern Territory, Australia - the latter half of the campaign coincided with the monsoon season. A range of scientific equipment was used to sample the inflow and outflow air from these storms; of particular importance were the NERC Dornier (low-level) and ARA Egrett (high-level outflow) aircraft. The Dornier held a range of aerosol, particle and chemical detectors for the purpose of analysing the planetary boundary layer (PBL), in the vicinity of tropical convection. The Egrett contained detection instrumentation for a range of sizes of aerosol and cloud particles (2 Condensation Particle Counters (CPC), CAPS, CIP, CPI) in the storm outflow. This allowed a quantifiable measurement to be made of the effect of deep tropical convection on the aerosol population in the Tropical Tropopause Layer (TTL). The ACTIVE campaign found that there were large numbers of aerosol particles in the 10 - 100 nm (up to 25,000 /cm3 STP) and 100 - 1000 nm (up to 600 /cm3) size ranges. These values, in many instances, surpassed those found in the PBL. The higher levels of aerosol found in the TTL compared to the PBL could indicate that aerosol nucleation was occurring in the TTL as a direct result of convective activity. Furthermore, the Egrett aircraft found distinct boundaries between the high levels of aerosol, which were found in cloud free regions, and very low numbers of aerosol, which were found in the cloudy regions (storm anvil). The air masses were determined, from back trajectories, to have been through convective uplift and were formerly part of the anvil cloud. The cloudy regions would have contained high levels of entrapped precursor gases. Reduced nucleation and cloud particle scavenging of aerosol and gases would give a

  9. A comprehensive dynamic model to investigate the stability problems of the rotor-bearing system due to multiple excitations

    NASA Astrophysics Data System (ADS)

    Zhang, Xuening; Han, Qinkai; Peng, Zhike; Chu, Fulei

    2016-03-01

    In this paper, a comprehensive dynamic model is proposed to analyze the dynamic behaviors of the rotor-bearing system. Three types of excitation including the bearing waviness, the unbalanced force and the finite number of balls (varying compliance effect) are considered. Based on the extended Jones-Harris model with five degrees of freedom, the load distribution and then the stiffness of the angular contact ball bearing are obtained theoretically. After introducing the three types of excitation into the model, the bearing stiffness matrix becomes time-varying and many parametric frequencies are found due to the multiple excitations. Then, the stability problems of the parametrically excited rotor-bearing system are investigated utilizing the discrete state transition matrix method (DSTM). The simple instability regions arising from the translational and the angular motions are analyzed respectively. The effects of the amplitude and the initial phase angle of the bearing waviness, the rotor eccentricity, the bearing preload and the damping of the rotating system on the instability regions are discussed thoroughly. It is shown that the waviness amplitudes have significant influences on the instability regions, while the initial phase angles of the waviness almost have no effect on the instability regions. The rotor eccentricity just affects the widths of the instability regions. The increasing of the bearing preload only shifts the positions of the instability regions. Damping could reduce the instability regions but it could not diminish the regions completely.

  10. An investigation of fatigue phenomenon in the upper limb muscle due to short duration pulses in an FES system

    NASA Astrophysics Data System (ADS)

    Naeem, Jannatul; Wong Azman, Amelia; Khan, Sheroz; Mohd Mustafah, Yasir

    2013-12-01

    Functional Electrical Stimulation (FES) is a method of artificially stimulating muscles or nerves in order to result in contraction or relaxation of muscles. Many studies have shown that FES system has helped patients to live a better lives especially those who are suffering from physical mobility. Unfortunately, one of the main limitations of an FES system besides of its high cost is largely due to muscle fatigue. Muscle fatigue will affect the training duration which could delay patients' recovery rate. In this paper, we analyzed the occurrence of this fatigue phenomenon in terms of stimulator parameters such as amplitude, frequency, pulse width and pulse shape. The objective of this investigation is to identify other key features of the FES system parameters in order to prolong the training duration among patients. The experiment has been done on a healthy person for the duration of one minute and later the muscles response will be observed. Resultant muscle response is recorded as force using force resistive sensor. The experimental results show muscles will get fatigue at a different rate as the frequency increases. The experiment also shows that the duty cycle is reciprocal to the resultant force.

  11. Elevated Ground Temperatures at Crude Oil Spill Sites due to Microbial Activity

    NASA Astrophysics Data System (ADS)

    Warren, E.; Bekins, B. A.

    2009-12-01

    Crude oil near the water table at spill sites near Bemidji and Cass Lake, Minnesota, has been undergoing aerobic and anaerobic biodegradation for decades. Because the reactions are exothermic, biodegradation of oil compounds will produce measurable temperature increases if heat is generated faster than it is transported away from the oil body. Subsurface temperatures at the two spill sites were measured with thermistors at multiple depths in groundwater monitoring wells and water-filled tubes in the vadose zone. Temperatures in selected wells were measured in the summer of 2007, 2008, and 2009. At the Bemidji site, temperatures measured in the summer ranged from a low of 6.3 oC in the background well to a high of 9.2 oC within wells in the oil-contaminated zone. From year to year, background minimum temperatures were constant within +/- 0.05 oC while maximum temperatures within the oil-contaminated zone remained within +/- 0.25 oC. Seasonal changes in temperature in the plume as measured by data loggers exceeded 4 oC, which was far greater than the year to year change in the summer measurements. Seasonal variability was greater near the water table than at depth. It is unclear whether this variability is due to subsurface hydrology or microbial activity. Temperatures in the vadose zone were warmer near and down-gradient from the oil body compared to the background indicating the heat from the oil and plume propagates up and outward into the vadose zone. At the Cass Lake site, summer temperatures in 2009 were 6.4 oC in the background and 11.5 oC in wells near the oil. Reaction rates inferred from chemical data were compared to heating required in a 3-dimension energy transport model of the subsurface. The increased temperature compared well to the expected heat production from biodegradation reactions occurring in the oil and plume. Results indicate that microbial activity in sediments contaminated with crude oil undergoing biodegradation can be detected using

  12. Evaluation of Activity Concentration Values and Doses due to the Transport of Low Level Radioactive Material

    SciTech Connect

    Rawl, Richard R; Scofield, Patricia A; Leggett, Richard Wayne; Eckerman, Keith F

    2010-04-01

    The International Atomic Energy Agency (IAEA) initiated an international Coordinated Research Project (CRP) to evaluate the safety of transport of naturally occurring radioactive material (NORM). This report presents the United States contribution to that IAEA research program. The focus of this report is on the analysis of the potential doses resulting from the transport of low level radioactive material. Specific areas of research included: (1) an examination of the technical approach used in the derivation of exempt activity concentration values and a comparison of the doses associated with the transport of materials included or not included in the provisions of Paragraph 107(e) of the IAEA Safety Standards, Regulations for the Safe Transport of Radioactive Material, Safety Requirements No. TS-R-1; (2) determination of the doses resulting from different treatment of progeny for exempt values versus the A{sub 1}/A{sub 2} values; and (3) evaluation of the dose justifications for the provisions applicable to exempt materials and low specific activity materials (LSA-I). It was found that the 'previous or intended use' (PIU) provision in Paragraph 107(e) is not risk informed since doses to the most highly exposed persons (e.g., truck drivers) are comparable regardless of intended use of the transported material. The PIU clause can also have important economic implications for co-mined ores and products that are not intended for the fuel cycle but that have uranium extracted as part of their industrial processing. In examination of the footnotes in Table 2 of TS-R-1, which identifies the progeny included in the exempt or A1/A2 values, there is no explanation of how the progeny were selected. It is recommended that the progeny for both the exemption and A{sub 1}/A{sub 2} values should be similar regardless of application, and that the same physical information should be used in deriving the limits. Based on the evaluation of doses due to the transport of low-level NORM

  13. Investigations of fungal secondary metabolites with potential anticancer activity.

    PubMed

    Balde, ElHadj Saidou; Andolfi, Anna; Bruyère, Céline; Cimmino, Alessio; Lamoral-Theys, Delphine; Vurro, Maurizio; Damme, Marc Van; Altomare, Claudio; Mathieu, Véronique; Kiss, Robert; Evidente, Antonio

    2010-05-28

    Fourteen metabolites, isolated from phytopathogenic and toxigenic fungi, were evaluated for their in vitro antigrowth activity for six distinct cancer cell lines, using the MTT colorimetric assay. Bislongiquinolide (1) and dihydrotrichodimerol (5), which belong to the bisorbicillinoid structural class, displayed significant growth inhibitory activity against the six cancer cell lines studied, while the remaining compounds displayed weak or no activity. The data show that 1 and 5 have similar growth inhibitory activities with respect to those cancer cell lines that display certain levels of resistance to pro-apoptotic stimuli or those that are sensitive to apoptosis. Quantitative videomicroscopy analysis revealed that 1 and 5 exert their antiproliferative effect through cytostatic and not cytotoxic activity. The preliminary results from the current study have stimulated further structure-activity investigations with respect to the growth inhibitory activity of compounds belonging to the bisorbicillinoid group.

  14. Modelling of cloud formation due to air-sea interactions in an energy-active zone

    NASA Astrophysics Data System (ADS)

    Kondratyev, K. Ya.; Khvorostyanov, V. I.

    1989-02-01

    A mesoscale 3D numerical model is described, with which detailed calculations have been made of turbulence and wind characteristics in the atmospheric boundary layer (ABL), as well as cloud particle size distribution, longwave and solar radiation fluxes and flux divergences, and atmosphere-ocean heat exchange. Based on numerical experiments simulating winter conditions of the Newfoundland energy-active zone of the ocean (EAZO), atmosphere-ocean energy exchange is investigated. It is shown that the basic mechanisms for the EAZO formation involve the following processes: (i) at the hydrological front between cold and warm ocean currents, the fluxes of sensible and latent heat grow significantly; (ii) at this front, in a particular synoptic situation, overcast low-level cloudiness forms, screening solar radiation so that in winter, the radiation budget at the front is reduced, and the radiative flux into the ocean is less than the energy release to the atmosphere; (iii) frequent occurrence of such synoptic situations with cloudiness decreases the oceanic enthalpy and creates negative SST anomalies. The transport of these anomalies by currents to the western coasts of the continents causes anomalies of weather and climate.

  15. Changes in EMG activity in the upper trapezius muscle due to local vibration exposure.

    PubMed

    Aström, Charlotte; Lindkvist, Markus; Burström, Lage; Sundelin, Gunnevi; Karlsson, J Stefan

    2009-06-01

    Exposure to vibration is suggested as a risk factor for developing neck and shoulder disorders in working life. Mechanical vibration applied to a muscle belly or a tendon can elicit a reflex muscle contraction, also called tonic vibration reflex, but the mechanisms behind how vibration could cause musculoskeletal disorders has not yet been described. One suggestion has been that the vibration causes muscular fatigue. This study investigates whether vibration exposure changes the development of muscular fatigue in the trapezius muscle. Thirty-seven volunteers (men and women) performed a sub-maximal isometric shoulder elevation for 3 min. This was repeated four times, two times with induced vibration and two times without. Muscle activity was measured before and after each 3-min period to look at changes in the electromyography parameters. The result showed a significantly smaller mean frequency decrease when performing the shoulder elevation with vibration (-2.51 Hz) compared to without vibration (-4.04 Hz). There was also a slightly higher increase in the root mean square when exposed to vibration (5.7% of maximal voluntary contraction) compared to without (3.8% of maximal voluntary contraction); however, this was not statistically significant. The results of the present study indicate that short-time exposure to vibration has no negative acute effects on the fatiguing of upper trapezius muscle.

  16. Anthropogenic wetlands due to over-irrigation of desert areas; A challenging hydrogeological investigation with extensive geophysical input

    NASA Astrophysics Data System (ADS)

    Behroozmand, A. A.; Teatini, P.; Pedersen, J. B. B.; Auken, E.; Tosatto, O.; Christiansen, A. V.

    2015-12-01

    During the last century, many large irrigation projects have been initiated in arid lands worldwide. Despite a tremendous increase in food production, a common problem when characterizing these zones is land degradation in form of waterlogging. As results, large volumes of water are lost due to surplus irrigation in regions where water availability is extremely challenging for both population survival and economic development. The Nubariya depression, Western Desert (Egypt), is a clear example of this mechanism. Following the reclamation of desert lands for agricultural production, an artificial brackish and contaminated lake developed in the area in the late 1990s and presently extends for about 2.5 km2. Available data provide evidence of a simultaneous general deterioration of the groundwater system. With the main objectives of understanding the hydrological evolution of the area, characterizing the hydrogeological setting and developing scenarios for artificial aquifer remediation and recharge, an extensive hydrogeophysical investigation was carried out in this challenging environment using Magnetic Resonance Sounding (MRS, also called surface NMR) and ground-based Transient EM (TEM). The integrated interpretation of the geophysical surveys, properly calibrated with a number of boreholes, provides a clear hydrogeological picture of the upper 100 m sedimentary structure, in terms of both lithology and groundwater quality. The information is then used to set up a regional groundwater flow and a local density-dependent flow and transport numerical model to reproduce the past evolution of the aquifer system and develop a few scenarios for artificial aquifer recharge using the treated waters provided by a nearby waste-water treatment plant. The research outcomes point the hydrological challenges that emerge for an effective management of water resources in reclaimed desert areas and highlight the effectiveness of integrating advanced geophysical and modeling

  17. Imbalance of Nature due to Anthropogenic Activities in the Bay of Bacorehuis, Sinaloa, Mexico

    NASA Astrophysics Data System (ADS)

    Torrecillas Nunez, C.; Cárdenas Cota, H.

    2013-05-01

    Pollution is further enhancing water scarcity by reducing water usability downstream, globally the most prevalent water quality problem is eutrophication, a result of high-nutrient loads, which substantially impairs beneficial uses of water. Projected food production needs and increasing wastewater effluents associated with an increasing population over the next three decades suggest a 10%-15% increase in the river input of nitrogen loads into coastal ecosystems (UNO, 2009). Our study in the Bay of Bacorehuis in the State of Sinaloa, which was carried out due to a request from local fishermen who wanted to find out the reason for fishing stocks depletion, confirmed this trend with the consequent imbalance of nature. Sinaloa depends heavily on intensive agricultural production to support its economy which in turn relies on water irrigation and the application of agro-chemicals. The research project included a desk top study of geophysical and environmental factors as well as sampling and testing of the water. In addition we carried out socio-economic research to find out the impact on the local community of the imbalance caused by anthropogenic activities in the watershed upstream from the Bay. Our research established that the Bay of Bacorehuis is contaminated by organic matter, bacteria coliforms, pesticides and mercury due to the discharge of surplus runoff generated by irrigation of farmlands into drainage networks as well as the discharge of untreated industrial and domestic wastewater form more than 24,000 inhabitants. The main contaminants detected in the water bodies were organic matter, faecal coliforms, mercury, dimethoate, endosulfan, heptachlor, DDE, DDT, organonitrogen, synthetic pyrethroid, chlorothalonil, ethion, endosulfan, diazinon, malathion and chlorpyrifos. Contaminants in sediments included the pesticides endosulfan, heptachlor, DDE, DDT, organophosphates, organonitrogen and synthetic pyrethroids. Natural water courses have been highly modified

  18. Active Control of Pressure Fluctuations due to Flow Over Helmholtz Resonators

    NASA Astrophysics Data System (ADS)

    KOOK, H.; MONGEAU, L.; FRANCHEK, M. A.

    2002-08-01

    Grazing flows over Helmholtz resonators may result in self-sustained flow oscillations at the Helmholtz acoustic resonance frequency of the cavity system. The associated pressure fluctuations may be undesirable. Many solutions have been proposed to solve this problem including, for example, leading edge spoilers, trailing edge deflectors, and leading edge flow diffusers. Most of these control devices are “passive”, i.e., they do not involve dynamic control systems. Active control methods, which do require dynamic controls, have been implemented with success for different cases of flow instabilities. Previous investigations of the control of flow-excited cavity resonance have used mainly one or more loudspeakers located within the cavity wall. In the present study, oscillated spoilers hinged near the leading edge of the cavity orifice were used. Experiments were performed using a cavity installed within the test section wall of a wind tunnel. A microphone located within the cavity was used as the feedback sensor. A loop shaping feedback control design methodology was used in order to ensure robust controller performance over varying flow conditions. Cavity pressure level attenuation of up to 20dB was achieved around the critical velocity (i.e., the velocity for which the fundamental excitation frequency matches the Helmholtz resonance frequency of the cavity), relative to the level in the presence of the spoiler held stationary. The required actuation effort was small. The spoiler peak displacement was typically only 4% of the mean spoiler angle (approximately 1‧). The control scheme was found to provide robust performance for transient operating conditions. Oscillated leading edge spoilers offer potential advantages over loudspeakers for cavity resonance control, including a reduced encumbrance (especially for low-frequency applications), and a reduced actuation effort.

  19. Tools to investigate how interprofessional education activities link to competencies

    PubMed Central

    West, Courtney; Veronin, Michael; Landry, Karen; Kurz, Terri; Watzak, Bree; Quiram, Barbara; Graham, Lori

    2015-01-01

    Integrating interprofessional education (IPE) activities and curricular components in health professions education has been emphasized recently by the inclusion of accreditation standards across disciplines. The Interprofessional Education Collaborative (IPEC) established IPE competencies in 2009, but evaluating how activities link to competencies has not been investigated in depth. The purpose of this project is to investigate how well two IPE activities align with IPEC competencies. To evaluate how our IPE activities met IPEC competencies, we developed a checklist and an observation instrument. A brief description of each is included as well as the outcomes. We analyzed Disaster Day, a simulation exercise that includes participants from Nursing, Medicine, and Pharmacy, and Interprofessional Healthcare Ethics (IPHCE), a course that introduced medical, nursing, and pharmacy students to ethical issues using didactic sessions and case discussions. While both activities appeared to facilitate the development of IPE competencies, Disaster Day aligned more with IPEC competencies than the IPHCE course and appears to be a more comprehensive way of addressing IPEC competencies. However, offering one IPE activity or curricular element is not sufficient. Having several IPE options available, utilizing the tools we developed to map the IPE curriculum and evaluating competency coverage is recommended. PMID:26208707

  20. Electrostatic Fields Near the Active Site of Human Aldose Reductase: 2. New Inhibitors and Complications due to Hydrogen Bonds†

    PubMed Central

    Xu, Lin; Cohen, Aina E.; Boxer, Steven G.

    2011-01-01

    Vibrational Stark effect spectroscopy was used to measure electrostatic fields in the hydrophobic region of the active site of human aldose reductase (hALR2). A new nitrile-containing inhibitor was designed and synthesized, and the x-ray structure of its complex, along with cofactor NADP+, with wild-type hALR2 was determined at 1.3 Å resolution. The nitrile is found to be in close proximity to T113, consistent with a hydrogen bond interaction. Two vibrational absorption peaks were observed at room temperature in the nitrile region when the inhibitor binds to wild-type hALR2, indicating that the nitrile probe experiences two different microenvironments, and these could be empirically separated into a hydrogen bonded and non-hydrogen bonded population by comparison with the mutant T113A, where a hydrogen bond to the nitrile is not present. Classical molecular dynamics simulations based on the structure predict a double-peaked distribution in protein electric fields projected along the nitrile probe. The interpretation of these two peaks as a hydrogen bond formation-dissociation process between the probe nitrile group and a nearby amino acid side chain is used to explain the observation of two IR bands, and the simulations were used to investigate the molecular details of this conformational change. Hydrogen bonding complicates the simplest analysis of vibrational frequency shifts as being due solely to electrostatic interactions through the vibrational Stark effect, and the consequences of this complication are discussed. PMID:21859105

  1. Active load path adaption in a simple kinematic load-bearing structure due to stiffness change in the structure's supports

    NASA Astrophysics Data System (ADS)

    Gehb, C. M.; Platz, R.; Melz, T.

    2016-09-01

    Load-bearing structures with kinematic functions enable and disable degrees of freedom and are part of many mechanical engineering applications. The relative movement between a wheel and the body of a car or a landing gear and an aircraft fuselage are examples for load-bearing systems with defined kinematics. In most cases, the load is transmitted through a predetermined load path to the structural support interfaces. However, unexpected load peaks or varying health condition of the system's supports, which means for example varying damping and stiffness characteristics, may require an active adjustment of the load path. However, load paths transmitted through damaged or weakened supports can be the reason for reduced comfort or even failure. In this paper a simplified 2D two mass oscillator with two supports is used to numerically investigate the potential of controlled adaptive auxiliary kinematic guidance elements in a load-bearing structure to adapt the load path depending on the stiffness change, representing damage of the supports. The aim is to provide additional forces in the auxiliary kinematic guidance elements for two reasons. On the one hand, one of the two supports that may become weaker through stiffness change will be relieved from higher loading. On the other hand, tilting due to different compliance in the supports will be minimized. Therefore, shifting load between the supports during operation could be an effective option.

  2. Using Geophysical Signatures to Investigate Temporal Changes Due to Source Reduction in the Subsurface Contaminated with Hydrocarbons

    EPA Science Inventory

    We investigated the geophysical response to subsurface hydrocarbon contamination source removal. Source removal by natural attenuation or by engineered bioremediation is expected to change the biological, chemical, and physical environment associated with the contaminated matrix....

  3. Students' Performance in Investigative Activity and Their Understanding of Activity Aims

    ERIC Educational Resources Information Center

    Gomes, Alessandro Damasio Trani; Borges, A. Tarciso; Justi, Rosaria

    2008-01-01

    This study investigates the relationship between the students' understanding of the aims of an investigative activity and their performance when conducting it. One hundred and eighty-one year nine students from a public middle school in Brazil took part in the study. Students working in pairs were asked to investigate two problems using a…

  4. Time allocation shifts and pollutant exposure due to traffic congestion: an analysis using the national human activity pattern survey.

    PubMed

    Zhang, Kai; Batterman, Stuart A

    2009-10-15

    Traffic congestion increases air pollutant exposures of commuters and urban populations due to the increased time spent in traffic and the increased vehicular emissions that occur in congestion, especially "stop-and-go" traffic. Increased time in traffic also decreases time in other microenvironments, a trade-off that has not been considered in previous time activity pattern (TAP) analyses conducted for exposure assessment purposes. This research investigates changes in time allocations and exposures that result from traffic congestion. Time shifts were derived using data from the National Human Activity Pattern Survey (NHAPS), which was aggregated to nine microenvironments (six indoor locations, two outdoor locations and one transport location). After imputing missing values, handling outliers, and conducting other quality checks, these data were stratified by respondent age, employment status and period (weekday/weekend). Trade-offs or time-shift coefficients between time spent in vehicles and the eight other microenvironments were then estimated using robust regression. For children and retirees, congestion primarily reduced the time spent at home; for older children and working adults, congestion shifted the time spent at home as well as time in schools, public buildings, and other indoor environments. Changes in benzene and PM(2.5) exposure were estimated for the current average travel delay in the U.S. (9 min day(-1)) and other scenarios using the estimated time shifts coefficients, concentrations in key microenvironments derived from the literature, and a probabilistic analysis. Changes in exposures depended on the duration of the congestion and the pollutant. For example, a 30 min day(-1) travel delay was determined to account for 21+/-12% of current exposure to benzene and 14+/-8% of PM(2.5) exposure. The time allocation shifts and the dynamic approach to TAPs improve estimates of exposure impacts from congestion and other recurring events.

  5. The spatial structure of underwater noise due to shipping activities in the Celtic Sea

    NASA Astrophysics Data System (ADS)

    Chen, Feng; Shapiro, Georgy; Thain, Richard

    2014-05-01

    Underwater noise is now classed as pollution alongside chemical pollution and marine litter (MSFD, 2012). Underwater noise from man-made sources arises from a number of sources including shipping activities. There are numerous examples of sound-induced effects recorded for various marine mammals, either in controlled situations, or opportunistically (MSFD-GES, 2012). Broad or narrow band continuous sounds, as well as pulses, have been documented to cause effects ranging from slight behaviour change, to activity disruption, avoidance or abandonment of preferred habitat (see Clark et al., 2009). Underwater ambient noise generated by shipping activities has increased significantly over the past decades (e.g. Mcdonald et al., 2006). Noise from shipping is a major contributor to the ambient noise levels in ocean, particularly at low (

  6. Changes in serum angiotensin I converting enzyme activity due to carbon disulfide exposure.

    PubMed

    Filipović, N; Bilalbegović, Z; Sefić, M; Djurić, D

    1984-01-01

    The activity of serum angiotensin I converting enzyme (ACE) was determined in 50 workers from a viscose factory in Banja Luka, Yugoslavia, and in 50 control subjects. Activity of serum ACE was significantly lower in workers exposed to carbon disulfide than in the control group. No correlation was found between a decrease of serum ACE in exposed workers and duration of exposure. These findings indicate that the serum ACE may be influenced by carbon disulfide, but the mechanism of these changes remains to be elucidated in this case.

  7. Impacts on ambient air quality due to flaring activities in one of Oman's oilfields.

    PubMed

    Abdul-Wahab, Sabah; Ali, Sappurd; Sardar, Sabir; Irfan, Naseem

    2012-01-01

    This work was conducted to assess the impacts on workplace and ambient air quality due to release of sulfur dioxide (SO(2)) into the atmosphere at Al-Noor production station, located in southern desert of Sultanate of Oman. The SO(2) is released because of oxidation of H(2)S to SO(2) on flaring of H(2)S rich off gas at the Al-Noor. In the first phase of the study, CALPUFF modeling system was used to predict the ground level concentrations of SO(2) emissions from the flare stacks. The evaluation of the modeling system was carried out by comparing the predicted results with that of the measured. In the second stage of the study, the estimated results were compared with the air quality standards/guidelines set by Omani regulatory authorities as well as by World Health Organization (WHO). It was concluded on the basis of current study that the sensitive individuals in the workplace of the Al-Noor could experience adverse health effects due to short-term exposure of SO(2).

  8. Modeling of geomagnetic activity due to passage of different structures and features of high speed streams

    NASA Astrophysics Data System (ADS)

    Mustajab, Fainana

    2016-07-01

    The modeling of terrestrial environment and relative geoeffectiveness due to high speed streams of different type and also compare their geoeffectiveness due to fine structures associated with streams, for example i) streams with different speed, ii) streams with different durations, iii) streams from different solar source and iv) associated fine structures. We also observed high speed streams during 1996 to 2011, and divided them into convenient groups based on their i) speed, ii) durations, iii) solar sources and iv) Dst groups. Performed them method of superposed-epoch analysis and other some statistical-analysis and correlation analysis between geomagnetic index Dst and plasma/field parameters during for both main phase and recovery phase. Streams having the passage duration ranging from 4.5 days to 10.5 days is 59% while other groups, having passage duration <4.5 days and > 10.5 days, contribute only near about 13%. When we observe group according to speed of streams, 30% of high speed streams are having the speed >650km/s and other groups are near about equally distributed in the range 400km/s to 650km/s. Out of 575 high speed streams, 45% streams are caused by single coronal hole, 20% due to multiple coronal hole, 24% by compound i.e: due to coronal hole and coronal mass ejections and only 10% from coronal mass ejections. The streams which are responsible for quiet, weak, moderate storms are nearly equal and only 12% streams cause severe storms. Dst gives best correlation with V(km/s) and BVres to the power 2 (x10res to the power 6) for over all storm time. B(nT) and BV(x10res to the power 3) represent good correlation with Dst during recovery phase duration for the speed groups. I observed the percentage of quiet storms decreases with increasing speed of streams. Near about equal percentage of weak storm are observed in each set of speed of stream. 17% moderate storms are found to contribute for the speed range 400-550km/s and ≈33% contribution is

  9. Investigations on the sporicidal and fungicidal activity of disinfectants.

    PubMed

    Lensing, H H; Oei, H L

    1985-12-01

    The sporicidal and fungicidal activity of disinfectants was studied in a suspension test. Glutaraldehyde 4%, sodium-dichloroisocyanurate-dihydrate (2400 ppm active chlorine) and peracetic acid 0.25% demonstrated after 30 min of exposure at 20 degrees C in the presence of 4% horse serum a clear activity against spores of Bacillus cereus. Under the same conditions formaldehyde 4% and glutaraldehyde 2% were also found to be sporicidal, but only after a longer time of exposure. Spores of Bacillus anthracis and B. cereus appeared to be comparably resistant against the investigated disinfectants, whereas conidiospores of Aspergillus fumigatus and Aspergillus niger were less resistant. Of the micro-organisms tested Candida albicans proved to be slightest resistant, while spores of Bacillus subtilis were found the most resistant.

  10. Investigating the active centre of the Scytalidium thermophilum catalase.

    PubMed

    Yuzugullu, Yonca; Trinh, Chi H; Fairhurst, Lucy; Ogel, Zumrut B; McPherson, Michael J; Pearson, Arwen R

    2013-04-01

    Almost all monofunctional haem catalases contain a highly conserved core containing the active site, which is connected to the exterior of the enzyme by three channels. These channels have been identified as potential routes for substrate flow and product release. To further investigate the role of these molecular channels, a series of mutants of Scytalidium thermophilum catalase were generated. The three-dimensional structures of four catalase variants, N155A, V123A, V123C and V123T, have been determined at resolutions of 2.25, 1.93, 1.9 and 1.7 Å, respectively. The V123C variant contains a new covalent bond between the S atom of Cys123 and the imidazole ring of the essential His82. This variant enzyme has only residual catalase activity and contains haem b instead of the normal haem d. The H82A variant demonstrates low catalase and phenol oxidase activities (0.2 and 20% of those of recombinant wild-type catalase-phenol oxidase, respectively). The N155A and N155H variants exhibit 4.5 and 3% of the wild-type catalase activity and contain haem d, showing that Asn155 is essential for catalysis but is not required for the conversion of haem b to haem d. Structural analysis suggests that the cause of the effect of these mutations on catalysis is the disruption of the ability of dioxygen substrates to efficiently access the active site. Additional mutants have been characterized biochemically to further probe the roles of the different channels. Introducing smaller or polar side chains in place of Val123 reduces the catalase activity. The F160V, F161V and F168V mutants show a marked decrease in catalase activity but have a much lower effect on the phenol oxidase activity, despite containing substoichiometric amounts of haem.

  11. Activity pattern and energy expenditure due to physical activity before and during pregnancy in healthy Swedish women.

    PubMed

    Lof, Marie; Forsum, Elisabet

    2006-02-01

    Human pregnancy is associated with increased requirements for dietary energy and this increase may be partly offset by reductions in physical activity during gestation. Studies in well-nourished women have shown that the physical activity level (PAL), obtained as the total energy expenditure (TEE) divided by the BMR, decreases in late pregnancy. However, it is not known if this decrease is really caused by reductions in physical activity or if it is the result of decreases in energy expenditure/BMR (the so-called metabolic equivalent, MET) for many activities in late pregnancy. In the present study activity pattern, TEE and BMR were assessed in twenty-three healthy Swedish women before pregnancy as well as in gestational weeks 14 and 32. Activity pattern was assessed using a questionnaire and heart rate recording. TEE was assessed using the doubly labelled water method and BMR was measured by means of indirect calorimetry. When compared to the pre-pregnant value, there was little change in the PAL in gestational week 14 but it was significantly reduced in gestational week 32. Results obtained by means of the questionnaire and by heart rate recording showed that the activity pattern was largely unaffected by pregnancy. The findings support the following conclusion: in a population of well-nourished women where the activity pattern is maintained during pregnancy, the increase in BMR represents approximately the main part of the pregnancy-induced increase in TEE, at least until gestational week 32.

  12. Monte Carlo investigation of the increased radiation deposition due to gold nanoparticles using kilovoltage and megavoltage photons in a 3D randomized cell model

    SciTech Connect

    Douglass, Michael; Bezak, Eva; Penfold, Scott

    2013-07-15

    Purpose: Investigation of increased radiation dose deposition due to gold nanoparticles (GNPs) using a 3D computational cell model during x-ray radiotherapy.Methods: Two GNP simulation scenarios were set up in Geant4; a single 400 nm diameter gold cluster randomly positioned in the cytoplasm and a 300 nm gold layer around the nucleus of the cell. Using an 80 kVp photon beam, the effect of GNP on the dose deposition in five modeled regions of the cell including cytoplasm, membrane, and nucleus was simulated. Two Geant4 physics lists were tested: the default Livermore and custom built Livermore/DNA hybrid physics list. 10{sup 6} particles were simulated at 840 cells in the simulation. Each cell was randomly placed with random orientation and a diameter varying between 9 and 13 {mu}m. A mathematical algorithm was used to ensure that none of the 840 cells overlapped. The energy dependence of the GNP physical dose enhancement effect was calculated by simulating the dose deposition in the cells with two energy spectra of 80 kVp and 6 MV. The contribution from Auger electrons was investigated by comparing the two GNP simulation scenarios while activating and deactivating atomic de-excitation processes in Geant4.Results: The physical dose enhancement ratio (DER) of GNP was calculated using the Monte Carlo model. The model has demonstrated that the DER depends on the amount of gold and the position of the gold cluster within the cell. Individual cell regions experienced statistically significant (p < 0.05) change in absorbed dose (DER between 1 and 10) depending on the type of gold geometry used. The DER resulting from gold clusters attached to the cell nucleus had the more significant effect of the two cases (DER {approx} 55). The DER value calculated at 6 MV was shown to be at least an order of magnitude smaller than the DER values calculated for the 80 kVp spectrum. Based on simulations, when 80 kVp photons are used, Auger electrons have a statistically insignificant (p

  13. Coma Morphology Due to an Extended Active Region and Implications for the Spin State of Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Samarasinha, Nalin H.

    2000-01-01

    We show that the circular character of continuum structures observed in the coma of comet Hale-Bopp around the perihelion passage is most likely due to a dust jet from a large extended active region on the surface. Coma morphology due to a wide jet is different from that due to a narrow jet. The latter shows foreshortening effects due to observing geometry, wider jet produces more circular features. This circularization effect provides a self-consistent explanation for the evolution of near-perihelion coma morphology. No changes in the direction of the rotational angular momentum vector are required during this period in contrast to the models of Schleicher et al. This circularization effect also enables us to produce near-circular coma features in the S-E quadrant during 1997 late February and therefore questions the basic premise on which Sekanina bases his morphological arguments for a gravitationally bound satellite nucleus.

  14. Detecting forest canopy change due to insect activity using Landsat MSS

    NASA Technical Reports Server (NTRS)

    Nelson, R. F.

    1983-01-01

    Multitemporal Landsat multispectral scanner data were analyzed to test various computer-aided analysis techniques for detecting significant forest canopy alteration. Three data transformations - differencing, ratioing, and a vegetative index difference - were tested to determine which best delineated gypsy moth defoliation. Response surface analyses were conducted to determine optimal threshold levels for the individual transformed bands and band combinations. Results indicate that, of the three transformations investigated, a vegetative index difference (VID) transformation most accurately delineates forest canopy change. Band 5 (0.6 to 0.7 micron ratioed data did nearly as well. However, other single bands and band combinations did not improve upon the band 5 ratio and VID results.

  15. An Investigation of Energy Transmission Due to Flexural Wave Propagation in Lightweight, Built-Up Structures. Thesis

    NASA Technical Reports Server (NTRS)

    Mickol, John Douglas; Bernhard, R. J.

    1986-01-01

    A technique to measure flexural structure-borne noise intensity is investigated. Two accelerometers serve as transducers in this cross-spectral technique. The structure-borne sound power is obtained by two different techniques and compared. In the first method, a contour integral of intensity is performed from the values provided by the two-accelerometer intensity technique. In the second method, input power is calculated directly from the output of force and acceleration transducers. A plate and two beams were the subjects of the sound power comparisons. Excitation for the structures was either band-limited white noise or a deterministic signal similar to a swept sine. The two-accelerometer method was found to be sharply limited by near field and transducer spacing limitations. In addition, for the lightweight structures investigated, it was found that the probe inertia can have a significant influence on the power input to the structure. In addition to the experimental investigation of structure-borne sound energy, an extensive study of the point harmonically forced, point-damped beam boundary value problem was performed to gain insight into measurements of this nature. The intensity formulations were also incorporated into the finite element method. Intensity mappings were obtained analytically via finite element modeling of simple structures.

  16. Infrared activation due to dynamic symmetry-breakdown in polyatomic molecules

    NASA Astrophysics Data System (ADS)

    Yamakawa, Koichiro

    2016-12-01

    Polyatomic molecules undergo symmetry breakdown upon vibration in contrast to diatomic ones and therefore have some infrared-inactive vibrational modes which are excited through the dipole transition owing to coupling with other modes. It is both the anharmonic potentials and high-order derivatives of the dipole operator with respect to the normal coordinates that cause the fundamental bands of inactive modes. Individual molecules with specific symmetries are discussed in detail, so that the modes which are activated by the dynamic symmetry-breakdown become clear.

  17. Drilling to investigate processes in active tectonics and magmatism

    NASA Astrophysics Data System (ADS)

    Shervais, J.; Evans, J.; Toy, V.; Kirkpatrick, J.; Clarke, A.; Eichelberger, J.

    2014-12-01

    Coordinated drilling efforts are an important method to investigate active tectonics and magmatic processes related to faults and volcanoes. The US National Science Foundation (NSF) recently sponsored a series of workshops to define the nature of future continental drilling efforts. As part of this series, we convened a workshop to explore how continental scientific drilling can be used to better understand active tectonic and magmatic processes. The workshop, held in Park City, Utah, in May 2013, was attended by 41 investigators from seven countries. Participants were asked to define compelling scientific justifications for examining problems that can be addressed by coordinated programs of continental scientific drilling and related site investigations. They were also asked to evaluate a wide range of proposed drilling projects, based on white papers submitted prior to the workshop. Participants working on faults and fault zone processes highlighted two overarching topics with exciting potential for future scientific drilling research: (1) the seismic cycle and (2) the mechanics and architecture of fault zones. Recommended projects target fundamental mechanical processes and controls on faulting, and range from induced earthquakes and earthquake initiation to investigations of detachment fault mechanics and fluid flow in fault zones. Participants working on active volcanism identified five themes: the volcano eruption cycle; eruption sustainability, near-field stresses, and system recovery; eruption hazards; verification of geophysical models; and interactions with other Earth systems. Recommended projects address problems that are transferrable to other volcanic systems, such as improved methods for identifying eruption history and constraining the rheological structure of shallow caldera regions. Participants working on chemical geodynamics identified four major themes: large igneous provinces (LIPs), ocean islands, continental hotspot tracks and rifts, and

  18. Biological Activities of Uric Acid in Infection Due to Enteropathogenic and Shiga-Toxigenic Escherichia coli

    PubMed Central

    Broome, Jacqueline E.; Lis, Agnieszka

    2016-01-01

    In previous work, we identified xanthine oxidase (XO) as an important enzyme in the interaction between the host and enteropathogenic Escherichia coli (EPEC) and Shiga-toxigenic E. coli (STEC). Many of the biological effects of XO were due to the hydrogen peroxide produced by the enzyme. We wondered, however, if uric acid generated by XO also had biological effects in the gastrointestinal tract. Uric acid triggered inflammatory responses in the gut, including increased submucosal edema and release of extracellular DNA from host cells. While uric acid alone was unable to trigger a chloride secretory response in intestinal monolayers, it did potentiate the secretory response to cyclic AMP agonists. Uric acid crystals were formed in vivo in the lumen of the gut in response to EPEC and STEC infections. While trying to visualize uric acid crystals formed during EPEC and STEC infections, we noticed that uric acid crystals became enmeshed in the neutrophilic extracellular traps (NETs) produced from host cells in response to bacteria in cultured cell systems and in the intestine in vivo. Uric acid levels in the gut lumen increased in response to exogenous DNA, and these increases were enhanced by the actions of DNase I. Interestingly, addition of DNase I reduced the numbers of EPEC bacteria recovered after a 20-h infection and protected against EPEC-induced histologic damage. PMID:26787720

  19. Can human local activities worsen the rise of temperature due to Climate Change?

    NASA Astrophysics Data System (ADS)

    Mateos, E.; Santana, J.; Deeb, A.; Grünwaldt, A.; Prieto, R.

    2013-12-01

    Several studies have shown a global scale temperature rise which in consequence, have brought up the need to propose various impact scenarios for this change on the planet and its life forms. Climate changes have a direct effect on human activities. Particularly these alterations have a negative impact on economy which in turn affects the most vulnerable and marginal population on developing nations. In a recent study based on 30 years climatological observed temperature in ten Mexican watersheds, from the period between 1970 and 1999, positive trend on maximum temperature were found in all watersheds. At each watershed at least 10 climatological stations from the net operated by the National Meteorological Service (Servicio Meterologico Nacional), whose data are maintained in the CLICOM database (Computerized Climate database), were selected. The climatological stations have at least 70% valid data per decade. In eight watersheds a maximum temperature trend oscillates between +0.5 to +1 oC every 30 years with a 95% confidence level. Nonetheless, in Rio Bravo and Rio Verde watersheds the tendencies are +1.75 and +2.75 oC over 30 years. The result in these two last watersheds evinces that: 1) there are fragile systems; 2) the human activities have a strong impact in those places, and 3) a principal anthropogenic influence on temperature rise is the change in land use. Temperature rised on Jalostitlan within Rio Verde watershed

  20. Are the changes in the peripheral brain-derived neurotrophic factor levels due to platelet activation?

    PubMed Central

    Serra-Millàs, Montserrat

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) plays an important role in central nervous system development, neurogenesis and neuronal plasticity. BDNF is also expressed in several non-neuronal tissues, and it could play an important role in other processes, such as cancer, angiogenesis, etc. Platelets are the major source of peripheral BDNF. However, platelets also contain high amounts of serotonin; they express specific surface receptors during activation, and a multitude of pro-inflammatory and immunomodulatory bioactive compounds are secreted from the granules. Until recently, there was insufficient knowledge regarding the relationship between BDNF and platelets. Recent studies showed that BDNF is present in two distinct pools in platelets, in α-granules and in the cytoplasm, and only the BDNF in the granules is secreted following stimulation, representing 30% of the total BDNF in platelets. BDNF has an important role in the pathophysiology of depression. Low levels of serum BDNF have been described in patients with major depressive disorder, and BDNF levels increased with chronic antidepressant treatment. Interestingly, there is an association between depression and platelet function. This review analyzed studies that evaluated the relationship between BDNF and platelet activation and the effect of treatments on both parameters. Only a few studies consider this possible confounding factor, and it could be very important in diseases such as depression, which show changes in both parameters. PMID:27014600

  1. Rate-dependent activation failure in isolated cardiac cells and tissue due to Na+ channel block

    PubMed Central

    Spindler, Anthony J.; Paterson, David; Noble, Denis

    2015-01-01

    While it is well established that class-I antiarrhythmics block cardiac sodium channels, the mechanism of action of therapeutic levels of these drugs is not well understood. Using a combination of mathematical modeling and in vitro experiments, we studied the failure of activation of action potentials in single ventricular cells and in tissue caused by Na+ channel block. Our computations of block and unblock of sodium channels by a theoretical class-Ib antiarrhythmic agent predict differences in the concentrations required to cause activation failure in single cells as opposed to multicellular preparations. We tested and confirmed these in silico predictions with in vitro experiments on isolated guinea-pig ventricular cells and papillary muscles stimulated at various rates (2–6.67 Hz) and exposed to various concentrations (5 × 10−6 to 500 × 10−6 mol/l) of lidocaine. The most salient result was that whereas large doses (5 × 10−4 mol/l or higher) of lidocaine were required to inhibit action potentials temporarily in single cells, much lower doses (5 × 10−6 mol/l), i.e., therapeutic levels, were sufficient to have the same effect in papillary muscles: a hundredfold difference. Our experimental results and mathematical analysis indicate that the syncytial nature of cardiac tissue explains the effects of clinically relevant doses of Na+ channel blockers. PMID:26342072

  2. Possible sea sediments due to glaciofluvial activity in Elysium Planitia, Mars

    NASA Astrophysics Data System (ADS)

    Nussbaumer, J.

    Observations of fluvial morphologies in southern Elysium Planitia strongly supports the hypothesis that water substantially affected this region during the relatively recent geologic past. As of yet, however, the extent of a standing body of water has been speculative. The observation of zig-zag features potentially analogous to those observed near the Wadden Sea on Earth [see 1] may help show in more detail the origin, activity, and fate of water in this region of Mars. These terrestrial analogs could constrain environmental scenarios concerning the formation of these features. We present a geomorphologic map of central Elysium Planitia, that aids in our interpretation of potentially site-specific depositional/erosional morphologies. Positive relief zig-zag features within the Medusae Fossae Formation (Themis Image V05875001) resemble similar structures on Earth observed at shorelines of flat regions. Glaciofluvial activity is indicated by linear features resembling straight glacial flutings, which could form aeolian yardangs subsequently. The flutings are associated with branches of inverted fluvial channels (Images Themis V05588002, MOC e1800307). Their excavated positive relief (height ~40 m) indicates, that the adjacent material was eroded by sublimation or aeolian activity. The channels possibly resemble ice marginal channels. A high resolution Digital Terrain Model of one of the channels suggests, that one channel is possibly running upslope. Fluvial processes could have operated at one location at one time, and glacial processes at another location at another time [2]. A glacial drainage system [see 3] is a possible terrestrial analog for one inverted fluvial channel on Mars (Themis Image V05875001). Flutings occur on the foreland of many glaciers and their length may provide important evidence for rapid advance over substantial distances. Flutings are the product of subglacial erosion and transport processes [4]. By assigning the different environmental

  3. Microbiological investigations into an outbreak of Pontiac fever due to Legionella micdadei associated with use of a whirlpool.

    PubMed Central

    Fallon, R J; Rowbotham, T J

    1990-01-01

    In the investigation of a large outbreak of non-pneumonic legionellosis at a leisure complex in Lochgoilhead, Scotland all direct cultures of environmental samples were initially negative for legionellae. Legionellae readily infect appropriate protozoa under suitable conditions, and following immunofluorescence to select specimens for special study, Legionella micdadei was isolated from whirlpool water via co-cultivation with Acanthamoeba polyphaga. L micdadei was also isolated, along with host amoebae, from the whirlpool filter. The use of amoebae in the isolation of legionellae from environmental (and other) sources can be of great value, especially if specimens shown by indirect immunofluorescence to contain legionellae fail to yield legionellae on routine culture. PMID:2199533

  4. Mitigation of Autoignition Due to Premixing in a Hypervelocity Flow Using Active Wall Cooling

    NASA Technical Reports Server (NTRS)

    Axdahl, Erik; Kumar, Ajay; Wilhite, Alan

    2013-01-01

    Preinjection of fuel on the forebody of an airbreathing vehicle is a proposed method to gain access to hypervelocity flight Mach numbers. However, this creates the possibility of autoignition either near the wall or in the core of the flow, thereby consuming fuel prematurely as well as increasing the amount of pressure drag on the vehicle. The computational fluid dynamics code VULCAN was used to conduct three dimensional simulations of the reacting flow in the vicinity of hydrogen injectors on a flat plate at conditions relevant to a Mach 12 notional flight vehicle forebody to determine the location where autoignition occurs. Active wall cooling strategies were formulated and simulated in response to regions of autoignition. It was found that tangential film cooling using hydrogen or helium were both able to nearly or completely eliminate wall autoignition in the flow domain of interest.

  5. CYCLIC MAGNETIC ACTIVITY DUE TO TURBULENT CONVECTION IN SPHERICAL WEDGE GEOMETRY

    SciTech Connect

    Kaepylae, Petri J.; Mantere, Maarit J.; Brandenburg, Axel

    2012-08-10

    We report on simulations of turbulent, rotating, stratified, magnetohydrodynamic convection in spherical wedge geometry. An initially small-scale, random, weak-amplitude magnetic field is amplified by several orders of magnitude in the course of the simulation to form oscillatory large-scale fields in the saturated state of the dynamo. The differential rotation is solar-like (fast equator), but neither coherent meridional poleward circulation nor near-surface shear layer develop in these runs. In addition to a poleward branch of magnetic activity beyond 50 Degree-Sign latitude, we find for the first time a pronounced equatorward branch at around 20 Degree-Sign latitude, reminiscent of the solar cycle.

  6. On Stellar Activity Enhancement Due to Interactions with Extrasolar Giant Planets.

    PubMed

    Cuntz; Saar; Musielak

    2000-04-20

    We present a first attempt to identify and quantify possible interactions between recently discovered extrasolar giant planets (and brown dwarfs) and their host stars, resulting in activity enhancement in the stellar outer atmospheres. Many extrasolar planets have masses comparable to or larger than Jupiter and are within a distance of 0.5 AU, suggesting the possibility of their significant influence on stellar winds, coronae, and even chromospheres. Beyond the well-known rotational synchronization, the interactions include tidal effects (in which enhanced flows and turbulence in the tidal bulge lead to increased magnetoacoustic heating and dynamo action) and direct magnetic interaction between the stellar and planetary magnetic fields. We discuss relevant parameters for selected systems and give preliminary estimates of the relative interaction strengths.

  7. The activated partial thromboplastin time of diluted plasma: variability due to the method of fibrin detection.

    PubMed Central

    Johnstone, I B

    1984-01-01

    The purpose of this study was to determine the effects of the dilution of plasma (1/3 in saline) on the kinetics of fibrin generation in the activated partial thromboplastin time (APTT) assay. The diluted APTT is considered to increase the sensitivity of the APTT test however, studies in our laboratory using an electro-optical fibrin detection system failed to show significant differences in APTT values obtained with diluted and undiluted canine plasma. Seventeen plasmas, including plasmas moderately and markedly deficient in intrinsic factor activity were assayed in the undiluted and diluted APTT assay using two methods for fibrin endpoint detection; a visual "tilt-tube" technique and an electro-optical detection system. In the former technique the endpoint was the formation of a visible fibrin web or clot; in the latter procedure the end point was the first detection of a change in optical density of the plasma. Optical density changes during fibrin formation were also recorded ( thrombokinetograms ). The results indicated that the electro-optical fibrin detection system failed to identify a prolongation of the APTT as a result of 1/3 plasma dilution; a prolongation that was consistently observed with the visual fibrin detection technique. Plasma dilution however, did significantly reduce the rate of fibrin production as indicated by the thrombokinetogram profile. It was concluded that the dilution of plasma with saline, as has been used to increase the sensitivity of the APTT assay procedure, has little effect on the time of onset of fibrin formation in a given plasma. The major effect appears to be on the way in which fibrin forms in that the polymerization/crosslinkage events associated with macroscopic fibrin production are delayed. PMID:6722646

  8. Reduced activity of alkaline phosphatase due to host-guest interactions with humic superstructures.

    PubMed

    Mazzei, Pierluigi; Oschkinat, Hartmut; Piccolo, Alessandro

    2013-11-01

    Nuclear Magnetic Resonance (NMR) spectroscopy was applied to directly study the interactions between the alkaline phosphatase enzyme (AP) and two different humic acids from a volcanic soil (HA-V) and a Lignite deposit (HA-L). Addition of humic matter to enzyme solutions caused signals broadening in (1)H-NMR spectra, and progressive decrease and increase of enzyme relaxation (T1 and T2) and correlation (τC) times, respectively. Spectroscopic changes were explained with formation of ever larger weakly-bound humic-enzyme complexes, whose translational and rotational motion was increasingly restricted. NMR diffusion experiments also showed that the AP diffusive properties were progressively reduced with formation of large humic-enzyme complexes. The more hydrophobic HA-L affected spectral changes more than the more hydrophilic HA-V. (1)H-NMR spectra also showed the effect of progressively greater humic-enzyme complexes on the hydrolysis of an enzyme substrate, the 4-nitrophenyl phosphate disodium salt hexahydrate (p-NPP). While AP catalysis concomitantly decreased NMR signals of p-NPP and increased those of nitrophenol, addition of humic matter progressively and significantly slowed down the rate of change for these signals. In agreement with the observed spectral changes, the AP catalytic activity was more largely inhibited by HA-L than by HA-V. Contrary to previous studies, in which humic-enzyme interactions were only indirectly assumed from changes in spectrophotometric behavior of enzyme substrates, the direct measurements of AP behavior by NMR spectroscopy indicated that humic materials formed weakly-bound host-guest complexes with alkaline phosphatase, and the enzyme catalytic activity was thereby significantly inhibited. These results suggest that the role of extracellular enzymes in soils may be considerably reduced when they come in contact with organic matter dissolved in the soil solution.

  9. Molecular dynamics investigations of mechanical behaviours in monocrystalline silicon due to nanoindentation at cryogenic temperatures and room temperature

    PubMed Central

    Du, Xiancheng; Zhao, Hongwei; Zhang, Lin; Yang, Yihan; Xu, Hailong; Fu, Haishuang; Li, Lijia

    2015-01-01

    Molecular dynamics simulations of nanoindentation tests on monocrystalline silicon (010) surface were conducted to investigate the mechanical properties and deformation mechanism from cryogenic temperature being 10 K to room temperature being 300 K. Furthermore, the load-displacement curves were obtained and the phase transformation was investigated at different temperatures. The results show that the phase transformation occurs both at cryogenic temperatures and at room temperature. By searching for the presence of the unique non-bonded fifth neighbour atom, the metastable phases (Si-III and Si-XII) with fourfold coordination could be distinguished from Si-I phase during the loading stage of nanoindentation process. The Si-II, Si-XIII, and amorphous phase were also found in the region beneath the indenter. Moreover, through the degree of alignment of the metastable phases along specific crystal orientation at different temperatures, it was found that the temperature had effect on the anisotropy of the monocrystalline silicon, and the simulation results indicate that the anisotropy of monocrystalline silicon is strengthened at low temperatures. PMID:26537978

  10. Use of multiple molecular subtyping techniques to investigate a Legionnaires' disease outbreak due to identical strains at two tourist lodges.

    PubMed Central

    Mamolen, M; Breiman, R F; Barbaree, J M; Gunn, R A; Stone, K M; Spika, J S; Dennis, D T; Mao, S H; Vogt, R L

    1993-01-01

    A multistate outbreak of Legionnaires' disease occurred among nine tour groups of senior citizens returning from stays at one of two lodges in a Vermont resort in October 1987. Interviews and serologic studies of 383 (85%) of the tour members revealed 17 individuals (attack rate, 4.4%) with radiologically documented pneumonia and laboratory evidence of legionellosis. A survey of tour groups staying at four nearby lodges and of Vermont-area medical facilities revealed no additional cases. Environmental investigation of common tour stops revealed no likely aerosol source of Legionella infection outside the lodges. Legionella pneumophila serogroup 1 was isolated from water sources at both implicated lodges, and the monoclonal antibody subtype matched those of the isolates from six patients from whom clinical isolates were obtained. The cultures reacted with monoclonal antibodies MAB1, MAB2, 33G2, and 144C2 to yield a 1,2,5,7 or a Benidorm 030E pattern. The strains were also identical by alloenzyme electrophoresis and DNA ribotyping techniques. The epidemiologic and laboratory data suggest that concurrent outbreaks occurred following exposures to the same L. pneumophila serogroup 1 strain at two separate lodges. Multiple molecular subtyping techniques can provide essential information for epidemiologic investigations of Legionnaires' disease. PMID:8253953

  11. Molecular dynamics investigations of mechanical behaviours in monocrystalline silicon due to nanoindentation at cryogenic temperatures and room temperature.

    PubMed

    Du, Xiancheng; Zhao, Hongwei; Zhang, Lin; Yang, Yihan; Xu, Hailong; Fu, Haishuang; Li, Lijia

    2015-11-05

    Molecular dynamics simulations of nanoindentation tests on monocrystalline silicon (010) surface were conducted to investigate the mechanical properties and deformation mechanism from cryogenic temperature being 10 K to room temperature being 300 K. Furthermore, the load-displacement curves were obtained and the phase transformation was investigated at different temperatures. The results show that the phase transformation occurs both at cryogenic temperatures and at room temperature. By searching for the presence of the unique non-bonded fifth neighbour atom, the metastable phases (Si-III and Si-XII) with fourfold coordination could be distinguished from Si-I phase during the loading stage of nanoindentation process. The Si-II, Si-XIII, and amorphous phase were also found in the region beneath the indenter. Moreover, through the degree of alignment of the metastable phases along specific crystal orientation at different temperatures, it was found that the temperature had effect on the anisotropy of the monocrystalline silicon, and the simulation results indicate that the anisotropy of monocrystalline silicon is strengthened at low temperatures.

  12. Investigations into the seeding of instabilities due to x-ray preheat in beryllium-based inertial confinement fusion targets

    SciTech Connect

    Loomis, E. N.; Greenfield, S. R.; Johnson, R. P.; Cobble, J. A.; Luo, S. N.; Montgomery, D. S.; Marinak, M. M.

    2010-05-15

    The geometry of inertial confinement fusion (ICF) capsules makes them susceptible to various types of hydrodynamic instabilities at different stages during an ICF implosion. From the beginnings of ICF research, it has been known that grain-level anisotropy and defects could be a significant source of instability seeding in solid beryllium capsules. We report on experiments conducted at the Trident laser facility [S. H. Batha et al., Rev. Sci. Instrum. 79, 10F305 (2008)] to measure dynamic surface roughening from hard x-ray preheat due to anisotropic thermal expansion. M-band emission from laser-produced gold plasma was used to heat beryllium targets with different amounts of copper doping to temperatures comparable to ICF ignition preheat levels. Dynamic roughening measurements were made on the surface away from the plasma at discrete times up to 8 ns after the beginning of the drive pulse using a surface displacement interferometer with nanometer scale sensitivity. Undoped large-grained targets were measured to roughen between 15 and 50 nm rms. Fine-grained, copper-doped targets were observed to roughen near the sensitivity limit of the interferometer. The results of this work have shed light on the effects of high-Z doping and microstructural refinement on the dynamics of differential thermal expansion and have shown that current ICF capsule designs using beryllium are very effective in reducing preheat related roughening ahead of the first shock.

  13. Reported foodborne outbreaks due to noroviruses in Belgium: the link between food and patient investigations in an international context.

    PubMed

    Baert, L; Uyttendaele, M; Stals, A; VAN Coillie, E; Dierick, K; Debevere, J; Botteldoorn, N

    2009-03-01

    The Belgian data for foodborne norovirus (NoV) outbreaks became available for the first time with the introduction of an extraction and detection protocol for NoV in the National Reference Laboratory for foodborne outbreaks in September 2006. In 2007, 10 NoV foodborne outbreaks were reported affecting 392 persons in Belgium. NoV became the most detected agent in foodborne outbreaks followed by Salmonella (eight foodborne outbreaks). The major implicated foods were sandwiches (4/10), where food handlers reported a history of gastroenteritis in two outbreaks. A food handler was implicated in the limited number of Belgian NoV outbreaks which is in accord with internationally recorded data. Forty foodborne and waterborne outbreak events due to NoV, epidemiological and/or laboratory confirmed, from 2000 to 2007 revealed that in 42.5% of the cases the food handler was responsible for the outbreak, followed by water (27.5%), bivalve shellfish (17.5%) and raspberries (10.0%).

  14. Optical Tools to Investigate Cellular Activity in the Intestinal Wall

    PubMed Central

    Boesmans, Werend; Hao, Marlene M; Berghe, Pieter Vanden

    2015-01-01

    Live imaging has become an essential tool to investigate the coordinated activity and output of cellular networks. Within the last decade, 2 Nobel prizes have been awarded to recognize innovations in the field of imaging: one for the discovery, use, and optimization of the green fluorescent protein (2008) and the second for the development of super-resolved fluorescence microscopy (2014). New advances in both optogenetics and microscopy now enable researchers to record and manipulate activity from specific populations of cells with better contrast and resolution, at higher speeds, and deeper into live tissues. In this review, we will discuss some of the recent developments in microscope technology and in the synthesis of fluorescent probes, both synthetic and genetically encoded. We focus on how live imaging of cellular physiology has progressed our understanding of the control of gastrointestinal motility, and we discuss the hurdles to overcome in order to apply the novel tools in the field of neurogastroenterology and motility. PMID:26130630

  15. Investigation of some biologic activities of Swertia longifolia Boiss

    PubMed Central

    Hajimehdipoor, H.; Esmaeili, S.; Shekarchi, M.; Emrarian, T.; Naghibi, F.

    2013-01-01

    Swertia species are widespread in Eastern and Southern Asian countries and used in traditional medicine as anti-pyretic, analgesic, gastro and liver tonic. Among different species, only Swertia longifolia grows in Iran. In this investigation, antioxidant, cytotoxic and acetylcholinesterase inhibitory activities of S. longifolia have been studied. Aerial parts and roots of the plant were collected, dried and extracted with methanol 80% (total extract). Different extracts of the plant were obtained using hexane, chloroform, ethyl acetate, methanol, methanol:water (1:1) and water, respectively. Cytotoxic activity was determined by MTT assay on MDBK, HepG2, MCF7, HT29 and A549 cell lines. Antioxidant activity was measured by 2,2-diphenyl-1-picryl hydrazyl (DPPH) free radicals and acetylcholinesterase inhibitory (AChEI) effect was evaluated based on Ellman’s method in 96-well microplates.The results showed no cytotoxicity of the plant extracts on MDBK, HepG2, MCF7, HT29 and A549 cell lines up to 100 μg/ml. All samples showed radical scavenging activity but methanol extract of aerial parts and ethyl acetate extract of the roots showed the highest effects.Total extract of the roots showed higher AChEI activity than the aerial parts. Among different extracts, chloroform and ethyl acetate extracts of the roots and chloroform and methanol:water extracts of the aerial parts were more potent in AChEI assay. It is concluded that aerial parts and roots of the plant are rich in antioxidant agents with no cytotoxicity on selected cell lines up to 100 μg/ml. Moreover, since antioxidant and AChEI activity of compounds play an important role in the treatment of Alzheimer’s disorder, this plant might be a potential candidate for isolation of antioxidant and AChEI compounds which could be used as supportive treatment of Alzheimer’s disease. PMID:24082894

  16. Comparative anthelmintic activity investigation of selected ethno-medicinal weeds

    NASA Astrophysics Data System (ADS)

    Pueblos, Kirstin Rhys S.; Bajalla, Mark; Pacheco, Dixie; Ganot, Sheila; Paig, Daisy; Tapales, Radyn; Lagare, Jeanne; Quimque, Mark Tristan J.

    2017-01-01

    Helminth infections are one of the seriously neglected potent diseases in many parts of the world. The problems of parasitic helminthes becoming resistant to currently available anthelmintic drugs pose a challenge for the search - relying on natural products - for new and better anthelmintics. In this paper, four abundant Philippine weeds: Chrysopogon aciculatus Trin. Cyperus brevifolius Rottb., Ruellia tuberosa Linn. and Saccharum spontaneum Linn. were investigated for their anthelmintic activities to establish basis of their folkloric claim. The hexane-soluble and chloroform-soluble extracts were obtained through sequential solvent partitioning of the crude ethanolic extract of the air-dried aerial part of each plant sample. Meanwhile, the decoction was obtained from fresh aerial part of the plant samples. All extracts were then subjected to in vitro anthelmintic screening at different concentration as per method of Ghosh, et al. against African nightcrawler earthworms (Eudrillus euginiae) in which the activity of the extracts was determined by correlation with time. The anthelmintic bioassay results revealed a dose-dependent toxicity relationship. It indicated relatively low anthelmintic activities of the decoction of the four plant samples as compared to their corresponding crude ethanol extracts. Among the crude ethanol extracts, C. brevifolius (CBE) gave fastest time to bring about paralysis and death to the test organisms at all concentrations tested. For the hexane extracts, R. tuberosa (RTH) gave better activity among other plant samples. Lastly, among the chloroform-soluble extracts, both that of C. brevifolius (CBC) and R. tuberosa (RTC) comparably showed strongest anthelmintic activities at all tested concentrations, thus, exhibited best anthelmintic activity that is remarkably comparable to the positive control, Mebendazole at the highest concentration tested. In fact, CBC and RTC showed highest anthelmintic potential compared to all extracts tested in

  17. Investigation kinetics mechanisms of adsorption malachite green onto activated carbon.

    PubMed

    Onal, Y; Akmil-Başar, C; Sarici-Ozdemir, C

    2007-07-19

    Lignite was used to prepare activated carbon (T3K618) by chemical activation with KOH. Pore properties of the activated carbon such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by t-plot based on N2 adsorption isotherm. BET surface area of activated carbon is determined as 1000 m2/g. Adsorption capacity of malachite green (MG) onto T3K618 activated carbon was investigated in a batch system by considering the effects of various parameters like initial concentration (100, 150 and 200 mg/L) and temperature (25, 40 and 50 degrees C). The adsorption process was relatively fast and equilibrium was reached after about 20 min for 100, 150 mg/L at all adsorption temperature. Equilibrium time for 200 mg/L was determined as 20 min and 40 min at 298, 313 and 323 K, respectively. Simple mass and kinetic models were applied to the experimental data to examine the mechanisms of adsorption and potential rate controlling steps such as external mass transfer, intraparticle diffusion. Pseudo second-order model was found to explain the kinetics of MG adsorption most effectively. It was found that both mass transfer and pore diffusion are important in determining the adsorption rates. The intraparticle diffusion rate constant, external mass transfer coefficient, film and pore diffusion coefficient at various temperatures were evaluated. The activation energy (Ea) was determined as 48.56, 63.16, 67.93 kJ/mol for 100, 150, 200 mg/L, respectively. The Langmiur and Freundlich isotherm were used to describe the adsorption equilibrium studies at different temperatures. Langmiur isotherm shows better fit than Freundlich isotherm in the temperature range studied. The thermodynamic parameters, such as DeltaG degrees, DeltaS and DeltaH degrees were calculated. The thermodynamics of dyes-T3K618 system indicates endothermic process.

  18. Inhibition of chlamydial infectious activity due to P2X7R-dependent phospholipase D activation.

    PubMed

    Coutinho-Silva, Robson; Stahl, Lynn; Raymond, Marie-Noëlle; Jungas, Thomas; Verbeke, Philippe; Burnstock, Geoffrey; Darville, Toni; Ojcius, David M

    2003-09-01

    Chlamydia trachomatis survives within host cells by inhibiting fusion between Chlamydia vacuoles and lysosomes. We show here that treatment of infected macrophages with ATP leads to killing of chlamydiae through ligation of the purinergic receptor, P2X(7)R. Chlamydial killing required phospholipase D (PLD) activation, as PLD inhibition led to rescue of chlamydiae in ATP-treated macrophages. However, there was no PLD activation nor chlamydial killing in ATP-treated P2X(7)R-deficient macrophages. P2X(7)R ligation exerts its effects by promoting fusion between Chlamydia vacuoles and lysosomes. P2X(7)R stimulation also resulted in macrophage death, but fusion with lysosomes preceded macrophage death and PLD inhibition did not prevent macrophage death. These results suggest that P2X(7)R ligation leads to PLD activation, which is directly responsible for inhibition of infection.

  19. Investigating Coincidence Techniques in Biomedical Applications of Neutron Activation Analysis

    NASA Astrophysics Data System (ADS)

    Chowdhury, P.; Gramer, R.; Tandel, S. K.; Reinhardt, C. J.

    2004-05-01

    While neutron activation analysis has been widely used in biomedical applications for some time, the use of non-radioactive tracer techniques, to monitor, for example, organ blood flow, is more recent. In these studies, pre-clinical animal models are injected with micro-spheres labeled with stable isotopes of elements that have a high neutron absorption cross-section. Subsequently, samples of blood and/or tissue from different locations in the body are subjected to neutron activation analysis to measure the propagation of the labeled micro-spheres through the body. Following irradiation, the counting (with high-resolution Ge detectors) is typically delayed by a few days to dissipate short-lived activity in the samples and improve signal-to-noise for the peaks of interest in the activation spectrum. The aim of the present study was to investigate whether coincidence techniques (for isotopes which decay via two-photon cascades) could improve signal-to-noise and turn-around times. The samples were irradiated at the 1 MW research reactor at the UMass Lowell Radiation Laboratory. The analysis of the multi-parameter coincidence data recorded in event-mode will be presented and compared with the standard method of recording singles spectra.

  20. Monthly Variability in Upper Ocean Biogeochemistry due to Mesoscale Eddy Activity in the Sargasso Sea

    NASA Technical Reports Server (NTRS)

    Sweeney, Erin N.

    2001-01-01

    A comparison of monthly biogeochemical measurements made from 1993 to 1995, combined with hydrography and satellite altimetry, was used to observe the impacts of nine eddy events on primary productivity and particle flux in the Sargasso Sea. Measurements of primary production, thorium-234 flux, nitrate+nitrite, and photosynthetic pigments made at the US JGOFS Bermuda Atlantic Time-series Study (BATS) site were used. During the three years of this study, four out of six high thorium-234 flux events over 1000 dpm/sq m/d occurred during the passage of an eddy. Primary production nearly as high as the spring bloom maximum was observed in two modewater eddies (May 1993 and July 1995). The 1994 spring bloom at BATS was suppressed by the passage of an anticyclone. Distinct phytoplankton community shifts were observed in mode-water eddies, which had an increased percentage diatoms and dinoflagelletes, and in cyclones, which had an increased percentage cyanobacteria (excluding Prochlorococcus). The difference in the observations of mode-water eddies and cyclones may result from the age of the eddy, which was very important to the biological response. In general, eddies that were one to two months old elicited a large biological response; eddies that were three months old may show a biological response and were accompanied by high thorium flux measurements, eddies that were four months old or older did not show a biological response or high thorium flux. Our conceptual model depicting the importance of temporal changes during eddy upwelling and decay fit the observations well in all 7 upwelling eddies. Additional information is needed to determine the importance of deeper mixed layers and winter mixing to the magnitude of the eddy impacts. Also, sampling generally captured only the beginning, end, and /or edge of an eddy due to the monthly to semi-monthly frequency of the measurements made at BATS. Lagrangian studies, higher resolution time-series, and/or more spatial

  1. Monthly Variability in Upper Ocean Biogeochemistry Due to Mesoscale Eddy Activity in the Sargasso Sea

    NASA Technical Reports Server (NTRS)

    Sweeney, Erin N.

    2001-01-01

    A comparison of monthly biogeochemical measurements made from 1993 to 1995, combined with hydrography and satellite altimetry, was used to observe the impacts of nine eddy events on primary productivity and particle flux in the Sargasso Sea. Measurements of primary production, thorium-234 flux, nitrate+nitrite, and photosynthetic pigments made at the US JGOFS Bermuda Atlantic Time-Series Study (BATS) site were used. During the three years of this study, four out of six high thorium-234 flux events over 1000 dpm/sq m/d occurred during the passage of an eddy. Primary production nearly as high as the spring bloom maximum was observed in two mode-water eddies (May 1993 and July 1995). The 1994 spring bloom at BATS was suppressed by the passage of an anticyclone. Distinct phytoplankton community shifts were observed in mode-water eddies, which had an increased percentage diatoms and dinoflagelletes, and in cyclones, which had an increased percentage cyanobacteria (excluding Prochlorococcus). The difference in the observations of mode-water eddies and cyclones may result from the age of the eddy, which was very important to the biological response. In general, eddies that were one to two months old elicited a large biological response; eddies that were three months old may show a biological response and were accompanied by high thorium flux measurements; eddies that were four months old or older did not show a biological response or high thorium flux. Our conceptual model depicting the importance of temporal changes during eddy upwelling and decay fit the observations well in all seven upwelling eddies. Additional information is needed to determine the importance of deeper mixed layers and winter mixing to the magnitude of the eddy impacts. Also, sampling generally captured only the beginning, end, and/or edge of an eddy due to the monthly to semi-monthly frequency of the measurements made at BATS. Lagrangian studies, higher resolution time-series, and/or more spatial

  2. Investigations on the change of texture of plant cells due to preservative treatments by digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Vora, Priyanka; Anand, Arun

    2014-10-01

    Texture change is observed in preserved fruits and vegetables. Responsible factors for texture change during preservative treatments are cell morphology, cell wall structure, cell turger, water content and some biochemical components, and also the environmental conditions. Digital Holographic microscopy (DHM) is a quantitative phase contrast imaging technique, which provides three dimensional optical thickness profiles of transparent specimen. Using DHM the morphology of plant cells preserved by refrigeration or stored in vinegar or in sodium chloride can be obtained. This information about the spatio-temporal evolution of optical volume and thickness can be an important tool in area of food processing. Also from the three dimensional images, the texture of the cell can be retrieved and can be investigated under varying conditions.

  3. [Investigation of vectors and reservoirs in an acute Chagas outbreak due to possible oral transmission in Aguachica, Cesar, Colombia].

    PubMed

    Soto, Hugo; Tibaduiza, Tania; Montilla, Marleny; Triana, Omar; Suárez, Diana Carolina; Torres Torres, Mariela; Arias, María Teresa; Lugo, Ligia

    2014-04-01

    Colombia recorded 11 cases of acute Chagas disease and 80 cases of oral contamination with Trypanosoma cruzi. The current study analyzes the entomological and parasitological characteristics of the outbreak in Aguachica, Cesar Department, in 2010. An interdisciplinary group of health professionals and regional university personnel conducted the laboratory tests in the patients and the investigation of the transmission focus. Eleven cases of acute Chagas diseases were detected in a single family in a dwelling with domiciliated triatomines and Rhodnius pallescens, Pantrongylus geniculatus, Eratyrus cuspidatus, and two Didelphis marsupialis opossums infected with T. cruzi in Attalea butyracea and Elaeis oleifera palm trees in the urban area of Aguachica. The study analyzes the role of R. pallescens and palm trees in the wild cycle of T. cruzi and in oral transmission of Chagas disease. Sporadic incursions by wild R. pallescens, P. geniculatus, and E. cuspidatus from the nearby palm trees into human dwellings may cause increasingly frequent outbreaks of oral Chagas disease.

  4. Investigation of coastal morphological changes due to river basin characteristics by means of remote sensing and GIS techniques.

    PubMed

    Seker, D Z; Goksel, C; Kabdasli, S; Musaoglu, N; Kaya, S

    2003-01-01

    The Riva River is located on the Anatolian (Asian) side of Istanbul by the Black Sea coast, with a wonderful sandy beach and delta formation which has been selected as the study area. The Riva is the largest river in this region, which flows into the Black Sea and also gives its' name to the area. The river carries some amount of sediments to the Black Sea. These particles cause considerable changes not only in the bed bathymetry and coastal boundaries of the river but also along the coastline of the Black Sea. The aim of this study is to determine these variations by means of satellite data and GIS. In the study, satellite images dated 1975, 1984, 1992 and 2001 have been used. At the end of the study, the possibility of observing bathymetric changes in front of the coastline by means of satellite data has been investigated and results were evaluated and visualised by means of GIS.

  5. Intentional Medication Non-Adherence Due to Interactive Toxicity Beliefs among HIV Positive Active Drug Users

    PubMed Central

    Kalichman, Seth C.; Kalichman, Moira O.; Cherry, Charsey; Hoyt, Ginger; Washington, Christopher; Grebler, Tamar; Merely, Cindy; Welles, Brandi

    2015-01-01

    Drug use poses significant challenges to medical management of HIV infection. While most research has focused on the influence of intoxication on unintentional adherence to HIV treatment, drug use may also lead to intentional non-adherence, particularly when individuals believe that mixing medications with drugs is harmful. This study examined whether interactive toxicity beliefs predict non-adherence to antiretroviral therapy (ART) over a prospective period of adherence monitoring. Men and women living with HIV who screened positive for drug use and were being treated with ART (N=530) completed computerized self-interviews, three prospective unannounced pill counts to measure ART adherence, provided urine specimens for drug screening, and HIV viral load results from medical records. Results showed that 189 (35%) participants indicated that they intentionally miss their ART when they are using drugs. These participants also reported common beliefs regarding the perceived hazards of mixing HIV medications with alcohol and other drugs. Multivariable models that controlled for demographic and health characteristics, as well as frequency of alcohol use, showed that intentional non-adherence predicted poorer ART adherence over the prospective month and also predicted poorer treatment outcomes as indexed by unsuppressed HIV viral load. These findings extend previous research to show that interactive toxicity beliefs and intentional non-adherence play a significant role in medication non-adherence for a substantial number of people living with HIV and should be actively addressed in HIV clinical care. PMID:26226250

  6. Pulmonary arterial hypertension in rats due to age-related arginase activation in intermittent hypoxia.

    PubMed

    Nara, Akina; Nagai, Hisashi; Shintani-Ishida, Kaori; Ogura, Sayoko; Shimosawa, Tatsuo; Kuwahira, Ichiro; Shirai, Mikiyasu; Yoshida, Ken-ichi

    2015-08-01

    Pulmonary arterial hypertension (PAH) is prevalent in patients with obstructive sleep apnea syndrome (OSAS). Aging induces arginase activation and reduces nitric oxide (NO) production in the arteries. Intermittent hypoxia (IH), conferred by cycles of brief hypoxia and normoxia, contributes to OSAS pathogenesis. Here, we studied the role of arginase and aging in the pathogenesis of PAH in adult (9-mo-old) and young (2-mo-old) male Sprague-Dawley rats subjected to IH or normoxia for 4 weeks and analyzed them with a pressure-volume catheter inserted into the right ventricle (RV) and by pulsed Doppler echocardiography. Western blot analysis was conducted on arginase, NO synthase isoforms, and nitrotyrosine. IH induced PAH, as shown by increased RV systolic pressure and RV hypertrophy, in adult rats but not in young rats. IH increased expression levels of arginase I and II proteins in the adult rats. IH also increased arginase I expression in the pulmonary artery endothelium and arginase II in the pulmonary artery adventitia. Furthermore, IH reduced pulmonary levels of nitrate and nitrite but increased nitrotyrosine levels in adult rats. An arginase inhibitor (N(ω)-hydroxy-nor-1-arginine) prevented IH-induced PAH and normalized nitrite and nitrate levels in adult rats. IH induced arginase up-regulation and PAH in adult rats, but not in young rats, through reduced NO production. Our findings suggest that arginase inhibition prevents or reverses PAH.

  7. LDEF meteoroid and debris special investigation group investigations and activities at the Johnson Space Center

    NASA Technical Reports Server (NTRS)

    See, Thomas H.; Warren, Jack L.; Zolensky, Michael E.; Sapp, Clyde A.; Bernhard, Ronald P.; Dardano, Claire B.

    1995-01-01

    Since the return of the Long Duration Exposure Facility (LDEF) in January, 1990, members of the Meteoroid and Debris Special Investigation Group (M&D SIG) at the Johnson Space Center (JSC) in Houston, Texas have been examining LDEF hardware in an effort to expand the knowledge base regarding the low-Earth orbit (LEO) particulate environment. In addition to the various investigative activities, JSC is also the location of the general Meteoroid & Debris database. This publicly accessible database contains information obtained from the various M&D SIG investigations, as well as limited data obtained by individual LDEF Principal Investigators. LDEF exposed approximately 130 m(exp 2) of surface area to the LEO particulate environment, approximately 15.4 m(exp 2) of which was occupied by structural frame components (i.e., longerons and intercoastals) of the spacecraft. The data reported here was obtained as a result of detailed scans of LDEF intercoastals, 68 of which reside at JSC. The limited amount of data presently available on the A0178 thermal control blankets was reported last year and will not be reiterated here. The data presented here are limited to measurements of crater diameters and their frequency of occurrence (i.e., flux).

  8. Nonlinear changes in brain electrical activity due to cell phone radiation.

    PubMed

    Marino, Andrew A; Nilsen, Erik; Frilot, Clifton

    2003-07-01

    We studied the effect of an electromagnetic field from a cellular telephone on brain electrical activity, using a novel analytical method based on a nonlinear model. The electroencephalogram (EEG) from rabbits was embedded in phase space and local recurrence plots were calculated and quantified using recurrence quantitation analysis to permit statistical comparisons between filtered segments of exposed and control epochs from individual rabbits. When the rabbits were exposed to the radiation from a standard cellular telephone (800 MHz band, 600 mW maximum radiated power) under conditions that simulated normal human use, the EEG was significantly affected in nine of ten animals studied. The effect occurred beginning about 100 ms after initiation of application of the field and lasted approximately 300 ms. In each case, the fields increased the randomness in the EEG. A control procedure ruled out the possibility that the observations were a product of the method of analysis. No differences were found between exposed and control epochs in any animal when the experiment was repeated after the rabbits had been sacrificed, indicating that absorption of radiation by the EEG electrodes could not account for the observed effect. No effect was seen when deposition of energy in the brain was minimized by repositioning the radiating antenna from the head to the chest, showing that the type of tissue that absorbed the energy determined the observed changes in the EEG. We conclude that, in normal use, the fields from a standard cellular telephone can alter brain function as a consequence of absorption of energy by the brain.

  9. Monitoring the Perturbation of Soil and Groundwater Microbial Communities Due to Pig Production Activities

    PubMed Central

    Hong, Pei-Ying; Yannarell, Anthony C.; Dai, Qinghua; Ekizoglu, Melike

    2013-01-01

    This study aimed to determine if biotic contaminants originating from pig production farms are disseminated into soil and groundwater microbial communities. A spatial and temporal sampling of soil and groundwater in proximity to pig production farms was conducted, and quantitative PCR (Q-PCR) was utilized to determine the abundances of tetracycline resistance genes (i.e., tetQ and tetZ) and integrase genes (i.e., intI1 and intI2). We observed that the abundances of tetZ, tetQ, intI1, and intI2 in the soils increased at least 6-fold after manure application, and their abundances remained elevated above the background for up to 16 months. Q-PCR further determined total abundances of up to 5.88 × 109 copies/ng DNA for tetZ, tetQ, intI1, and intI2 in some of the groundwater wells that were situated next to the manure lagoon and in the facility well used to supply water for one of the farms. We further utilized 16S rRNA-based pyrosequencing to assess the microbial communities, and our comparative analyses suggest that most of the soil samples collected before and after manure application did not change significantly, sharing a high Bray-Curtis similarity of 78.5%. In contrast, an increase in Bacteroidetes and sulfur-oxidizing bacterial populations was observed in the groundwaters collected from lagoon-associated groundwater wells. Genera associated with opportunistic human and animal pathogens, such as Acinetobacter, Arcobacter, Yersinia, and Coxiella, were detected in some of the manure-treated soils and affected groundwater wells. Feces-associated bacteria such as Streptococcus, Erysipelothrix, and Bacteroides were detected in the manure, soil, and groundwater ecosystems, suggesting a perturbation of the soil and groundwater environments by invader species from pig production activities. PMID:23396341

  10. Investigation of an Axial Fan—Blade Stress and Vibration Due to Aerodynamic Pressure Field and Centrifugal Effects

    NASA Astrophysics Data System (ADS)

    Xu, Cheng; Amano, Ryoichi Samuel; Lee, Eng Kwong

    A 1.829m (6ft) diameter industrial large flow-rate axial fan operated at 1770rpm was studied experimentally in laboratory conditions. The flow characteristics on the fan blade surfaces were investigated by measuring the pressure distributions on the blade suction and pressure surfaces and the results were discussed by comparing with analytical formulations and CFD. Flow visualizations were also performed to validate the flow characteristics near the blade surface and it was demonstrated that the flow characteristics near the fan blade surface were dominated by the centrifugal force of the fan rotation which resulted in strong three-dimensional flows. The time-dependent pressure measurement showed that the pressure oscillations on the fan blade were significantly dominated by vortex shedding from the fan blades. It was further demonstrated that the pressure distributions during the fan start-up were highly unsteady, and the main frequency variation of the static pressure was much smaller than the fan rotational frequency. The time-dependent pressure measurement when the fan operated at a constant speed showed that the magnitude of the blade pressure variation with time and the main variation frequency was much smaller than the fan rotational frequency. The pressure variations that were related to the vortex shedding were slightly smaller than the fan rotational frequency. The strain gages were used to measure the blade stress and the results were compared with FEA results.

  11. Investigation of scaling characteristics for defining design environments due to transient ground winds and near-field, nonlinear acoustic fields

    NASA Technical Reports Server (NTRS)

    Shih, C. C.

    1973-01-01

    In order to establish a foundation of scaling laws for the highly nonlinear waves associated with the launch vehicle, the basic knowledge of the relationships among the paramaters pertinent to the energy dissipation process associated with the propagation of nonlinear pressure waves in thermoviscous media is required. The problem of interest is to experimentally investigate the temporal and spacial velocity profiles of fluid flow in a 3-inch open-end pipe of various lengths, produced by the propagation of nonlinear pressure waves for various diaphragm burst pressures of a pressure wave generator. As a result, temporal and spacial characteristics of wave propagation for a parametric set of nonlinear pressure waves in the pipe containing air under atmospheric conditions were determined. Velocity measurements at five sections along the pipes of up to 210 ft. in length were made with hot-film anemometers for five pressure waves produced by a piston. The piston was derived with diaphragm burst pressures at 20, 40, 60, 80 and 100 psi in the driver chamber of the pressure wave generator.

  12. The Spitzer discovery of a galaxy with infrared emission solely due to AGN activity

    NASA Astrophysics Data System (ADS)

    Hony, S.; Kemper, F.; Woods, P. M.; van Loon, J. Th.; Gorjian, V.; Madden, S. C.; Zijlstra, A. A.; Gordon, K. D.; Indebetouw, R.; Marengo, M.; Meixner, M.; Panuzzo, P.; Shiao, B.; Sloan, G. C.; Roman-Duval, J.; Mullaney, J.; Tielens, A. G. G. M.

    2011-07-01

    Aims: We present an analysis of a galaxy (SAGE1CJ053634.78-722658.5) at a redshift of 0.14 of which the infrared (IR) emission is entirely dominated by emission associated with the active galactic nucleus. Methods: We present the 5-37 μm Spitzer/IRS spectrum and broad wavelength spectral energy distribution (SED) of SAGE1CJ053634.78-722658.5, an IR point-source detected by Spitzer/SAGE. The source was observed in the SAGE-Spec program and was included to determine the nature of sources with deviant IR colours. The spectrum shows a redshifted (z = 0.14 ± 0.005) silicate emission feature with an exceptionally high feature-to-continuum ratio and weak polycyclic aromatic hydrocarbon (PAH) emission bands. We compare the source with models of emission from dusty tori around AGNs. We present a diagnostic diagram that will help to identify similar sources based on Spitzer/MIPS and Herschel/PACS photometry. Results: The SED of SAGE1CJ053634.78-722658.5 is peculiar because it lacks far-IR emissiondue to cold dust and a clear stellar counterpart. We find that the SED and the IR spectrum can be understood as emission originating from the inner ~10 pc around an accreting black hole. There is no need to invoke emission from the host galaxy, either from the stars or from the interstellar medium, although a possible early-type host galaxy cannot be excluded based on the SED analysis. The hot dust around the accretion disk gives rise to a continuum, which peaks at 4 μm, whereas the strong silicate features may arise from optically thin emission of dusty clouds within ~10 pc around the black hole. The weak PAH emission does not appear to be linked to star formation, as star formation templates strongly over-predict the measured far-IR flux levels. Conclusions: The SED of SAGE1CJ053634.78-722658.5 is rare in the local universe but may be more common in the more distant universe. The conspicuous absence of host-galaxy IR emission places limits on the far-IR emission arising from

  13. Investigation of the radiation risk due to environmental contamination by 241Am from lightning rods disposed at uncontrolled garbage dumps.

    PubMed

    Marumo, Júlio T; Isiki, Vera L K; Miyamoto, Hissae; Ferreira, Rafael V P; Bellini, Maria H; de Lima, Luis F C P

    2008-02-01

    Radioactive lightning rods were manufactured in Brazil until 1989, when the licenses for using radioactive sources in these products were lifted by the national nuclear authority. Since then, these rods have been replaced by the Franklin type and collected as radioactive waste. However, only 20% of the estimated total number of installed rods has been delivered to the Brazilian Nuclear Commission. This situation causes concern, since there is the possibility of the rods to be disposed as domestic waste. In Brazil, 64% of the municipal solid waste is disposed at garbage dumps without sufficient control. In addition, (241)Am, the radionuclide most commonly employed, is classified as a high-toxicity element, when incorporated. In the present study, (241)Am migration experiments were performed by means of a lysimeter system, in order to evaluate the risk of contamination caused by radioactive lightning rods disposed as common solid waste. (241)Am sources removed from lightning rods were placed inside lysimeters filled with organic waste that was collected at the restaurant of the Instituto de Pesquisas Energéticas e Nucleares. The generated leachate was periodically analyzed, and characteristics such as pH, redox potential, solid content and the concentration of the radioactive material were determined. The equivalent dose for members of the public was calculated considering ingestion of contaminated drinking water as the major path of exposure. Estimated doses were about 20-times below the effective dose limit of 1 mSv year(-1) for members of the public as recommended by the International Commission on Radiological Protection. This suggests the radiation risk caused by lightning rods disposed at uncontrolled garbage dumps to be low. It should be noted, however, that the number of investigated lightning rods was quite small. The results of this study might therefore not be entirely representative and should be interpreted with care. They provide, however, a very first

  14. Active control: an investigation method for combustion instabilities

    NASA Astrophysics Data System (ADS)

    Poinsot, T.; Yip, B.; Veynante, D.; Trouvé, A.; Samaniego, J. M.; Candel, S.

    1992-07-01

    Closed-loop active control methods and their application to combustion instabilities are discussed. In these methods the instability development is impeded with a feedback control loop: the signal provided by a sensor monitoring the flame or pressure oscillations is processed and sent back to actuators mounted on the combustor or on the feeding system. Different active control systems tested on a non-premixed multiple-flame turbulent combustor are described. These systems can suppress all unstable plane modes of oscillation (i.e. low frequency modes). The active instability control (AIC) also constitutes an original and powerful technique for studies of mechanisms leading to instability or resulting from the instability. Two basic applications of this kind are described. In the first case the flame is initially controlled with AIC, the feedback loop is then switched off and the growth of the instability is analysed through high speed Schlieren cinematography and simultaneous sound pressure and reaction rate measurements. Three phases are identified during th growth of the oscillations: (1) a linear phase where acoustic waves induce a flapping motion of the flame sheets without interaction between sheets, (2) a modulation phase, where flame sheets interact randomly and (3) a nonlinear phase where the flame sheets are broken and a limit cycle is reached. In the second case we investigate different types of flame extinctions associated with combustion instability. It is shown that pressure oscillations may lead to partial or total extinctions. Extinctions occur in various forms but usually follow a rapid growth of pressure oscillations. The flame is extinguished during the modulation phase observed in the initiation experiments. In these studies devoted to transient instability phenomena, the control system constitutes a unique investigation tool because it is difficult to obtain the same information by other means. Implications for modelling and prediction of

  15. Investigation of MEK activity in COS7 cells entering mitosis.

    PubMed

    Shi, Huaiping; Zhang, Tianying; Yi, Yongqing; Luo, Jun

    2014-12-01

    Although the mitogen-activated protein kinase (MAPK) pathway has been extensively investigated, numerous events remain unclear. In the present study, we examined mitogen-activated protein kinase kinase (MEK) expression from interphase to mitosis. Following nocodazole treatment, COS7 cells gradually became round as early as 4 h after treatment. Cyclin B1 expression gradually increased from 4 to 24 h in the presence of nocodazole. When cells were treated with nocodazole for 4 h, the level of epidermal growth factor (EGF)-mediated MEK phosphorylation did not significantly change between nocodazole-untreated and -treated (4 h) cells (P>0.05). However, EGF-mediated MEK phosphorylation was significantly inhibited upon treatment with nocodazole for 8 and 24 h compared to nocodazole-untreated cells (P<0.05). MEK phosphorylation levels were comparable between 1, 5, 10 and 50 ng/ml EGF treatments. Phorbol 12-myristic 13-acetate (PMA) did not activate MEK in mitotic cells. Following treatment of COS7 cells at the interphase with AG1478 or U0126, MEK phosphorylation was blocked. In addition, the investigation of the expression of proteins downstream of MEK demonstrated that EGF does not significantly affect the phosphorylation level of extracellular-signal-regulated kinase (ERK), ribosomal protein S6 kinase (RSK) and Elk in mitotic cells (P>0.05). The results showed that MEK expression is gradually inhibited from cell interphase to mitosis, and that MEK downstream signaling is affected by this inhibition, which probably reflects the requirements of cell physiology during mitosis.

  16. Investigating seasonal gravity wave activity in the summer polar mesosphere

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Taylor, M. J.; Randall, C. E.; Lumpe, J. D.; Siskind, D. E.; Bailey, S. M.; Russell, J. M.

    2015-05-01

    The NASA Aeronomy of Ice in the Mesosphere (AIM) satellite is the first spaceborne mission dedicated to studying high-altitude (~83 km) Polar Mesospheric Clouds (PMCs). Since its launch in 2007, the Cloud Imaging and Particle Size (CIPS) instrument onboard AIM has obtained large-field, high resolution (25 km2/pixel) images of the PMCs, enabling a unique investigation of mesospheric gravity wave activity in the summer polar mesosphere where previous measurements have been sparse. In this study, we have analyzed 12 consecutive seasons of AIM/CIPS PMC albedo data to determine the statistical properties of medium and large horizontal scale (>100 km) gravity waves present in the PMC data. Over 60,000 wave events with horizontal scale-sizes ranging up to >2000 km have been identified and measured, revealing a wealth of wave events particularly in the ~300-800 km range where our analysis sensitivity is largest. These data are ideal for investigating the intra-seasonal, inter-annual and hemispheric variability of these waves as observed over the whole summer polar cap regions. Throughout this 6 year study, the wave activity in the southern hemisphere was found to be consistently 10-15% higher than in the northern hemisphere and both the northern and southern hemisphere wave activity was determined to decrease systematically (by ~15%) during the course of each summer season. This decrease agrees well with previous seasonal stratospheric studies of variations in the wave energy, suggesting a direct influence of the lower atmospheric sources on polar mesospheric dynamics. Very similar and consistent results were also found from season to season in both hemispheres providing new information for gravity wave modeling and dynamical studies of the high-latitude summer-time mesosphere.

  17. Seal Investigations of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Taylor, Shawn; Oswald, Jay; DeCastro, Jonathan A.

    2006-01-01

    In an effort to improve upon current thermal active clearance control methods, a first generation, fast-acting mechanically actuated, active clearance control system has been designed and installed into a non-rotating test rig. In order to harvest the benefit of tighter blade tip clearances, low-leakage seals are required for the actuated carrier segments of the seal shroud to prevent excessive leakage of compressor discharge (P3) cooling air. The test rig was designed and fabricated to facilitate the evaluation of these types of seals, identify seal leakage sources, and test other active clearance control system concepts. The objective of this paper is to present both experimental and analytical investigations into the nature of the face-seal to seal-carrier interface. Finite element analyses were used to examine face seal contact pressures and edge-loading under multiple loading conditions, varied E-seal positions and two new face seal heights. The analyses indicated that moving the E-seal inward radially and reducing face seal height would lead to more uniform contact conditions between the face seal and the carriers. Lab testing confirmed that moving the balance diameter inward radially caused a decrease in overall system leakage.

  18. Investigating primary marine aerosol properties: CCN activity of sea salt and mixed particles

    NASA Astrophysics Data System (ADS)

    King, S. M.; Butcher, A. C.; Rosenoern, T.; Coz, E.; Lieke, K. I.; de Leeuw, G.; Nilsson, E. D.; Bilde, M.

    2012-04-01

    Sea salt particles ejected as a result of bubbles bursting from artificial seawater in a closed stainless steel tank were sampled for size distribution, morphology, and cloud condensation nucleus (CCN) activity. The two-component artificial seawater consisted of salt, either NaCl or sea salt, and one organic compound in deionized water. Several organic molecules representative of oceanic organic matter were investigated. Bubbles were generated either by aeration through a porous diffuser or by water jet impingement on the surface of the artificial seawater. The effect of bubble lifetime, which was controlled by varying the depth of the diffuser in the water column, on particle size and CCN activity was investigated and was found to be insignificant for the organic compounds studied. The CCN activities of particles produced from diffuser-generated bubbles were generally governed by the high hygroscopicity of salt, such that activation was indistinguishable from that of salt, except in the case of very low mass ratio of salt to organic matter in the seawater solution. There was, however, a considerable decrease in CCN activity for particles produced from jet impingement on seawater that had a salinity of 10‰ and contained 0.45 mM of sodium laurate, an organic surfactant. The production of a thick foam layer from impingement may explain the difference in activation and supports hypotheses that particle production from the two methods of generating bubbles is not similar. Accurate conclusions from observed CCN activities of particles from artificial seawater containing organic matter require knowledge of the CCN activity of the inorganic component, especially as a small amount of the inorganic can heavily influence activation. Therefore, the CCN activity of both artificial sea salt and NaCl were measured and compared. Part of the discrepancy observed between the CCN activities of the two salts may be due to morphological differences, which were investigated using

  19. Alterations in heart sarcolemmal Ca2(+)-ATPase and Ca2(+)-binding activities due to oxygen free radicals.

    PubMed

    Kaneko, M; Singal, P K; Dhalla, N S

    1990-01-01

    Effects of oxygen free radicals on Ca2+/Mg2+ ATPase and ATP-independent Ca2(+)-binding activities were examined in rat heart sarcolemma. Membranes were incubated with different oxygen radical generating media such as xanthine + xanthine oxidase, hydrogen peroxide, and hydrogen peroxide + Fe2+. In the presence of xanthine + xanthine oxidase, Ca2+ ATPase activity was stimulated and this effect was prevented by the addition of superoxide dismutase. Hydrogen peroxide also showed a significant increase in Ca2(+)-ATPase activity in a dose-dependent manner and this effect was blocked by catalase. On the other hand, a combination of hydrogen peroxide + Fe2+ decreased Ca2(+)-ATPase activity; this depression was prevented by the addition of D-mannitol. The observed change in Ca2(+)-ATPase activity due to oxygen free radicals was associated with changes in Vmax, whereas Ka remained unaffected. Both xanthine + xanthine oxidase and hydrogen peroxide increased whereas, hydrogen peroxide + Fe2+ inhibited the ATP-independent Ca2(+)-binding activities. It is suggested that oxygen free radicals may influence Ca2+ movements in the cell by altering the Ca2+/Mg2+ ATPase and Ca2(+)-binding activities of the membrane and these effects may be oxygen-radical species specific.

  20. Changes in antioxidant and antiinflammatory activity of black bean (Phaseolus vulgaris L.) protein isolates due to germination and enzymatic digestion.

    PubMed

    López-Barrios, Lidia; Antunes-Ricardo, Marilena; Gutiérrez-Uribe, Janet A

    2016-07-15

    Germination is an inexpensive process to improve the nutritional properties of legumes. The effect of germinating black bean seeds on the production of cotyledon protein hydrolysates (CPH) with antioxidant and antiinflammatory activities was analyzed in this research. After simulated enzymatic digestion, the oxygen radical absorbance capacity (ORAC) of CPH obtained from germinated black beans was lower than that observed for raw cotyledons. There were no significant differences among CPH cellular antioxidant activities (CAA), except for the high CAA of the 120 min hydrolysate obtained from one day germinated black bean cotyledons. The most significant changes due to germination and enzymatic hydrolysis were observed for the inhibition of nitric oxide (NO) production in macrophages. The NO synthesis inhibition observed for raw CPH was reduced after simulated gastrointestinal digestion but for germinated samples the inhibition was doubled. Peptides derived from cell wall proteins produced during germination could be responsible of antiinflammatory activity.

  1. Quality investigation of hydroxyprogesterone caproate active pharmaceutical ingredient and injection

    PubMed Central

    Chollet, John L.; Jozwiakowski, Michael J.

    2012-01-01

    The purpose of this study was to investigate the quality of hydroxyprogesterone caproate (HPC) active pharmaceutical ingredient (API) sources that may be used by compounding pharmacies, compared to the FDA-approved source of the API; and to investigate the quality of HPC injection samples obtained from compounding pharmacies in the US, compared to the FDA-approved product (Makena®). Samples of API were obtained from every source confirmed to be an original manufacturer of the drug for human use, which were all companies in China that were not registered with FDA. Eight of the ten API samples (80%) did not meet the impurity specifications required by FDA for the API used in the approved product. One API sample was found to not be HPC at all; additional laboratory testing showed that it was glucose. Thirty samples of HPC injection obtained from com pounding pharmacies throughout the US were also tested, and eight of these samples (27%) failed to meet the potency requirement listed in the USP monograph for HPC injection and/or the HPLC assay. Sixteen of the thirty injection samples (53%) exceeded the impurity limit setforthe FDA-approved drug product. These results confirm the inconsistency of compounded HPC Injections and suggest that the risk-benefit ratio of using an unapproved compounded preparation, when an FDA-approved drug product is available, is not favorable. PMID:22329865

  2. Self-Directed Weight Loss Strategies: Energy Expenditure Due to Physical Activity Is Not Increased to Achieve Intended Weight Loss

    PubMed Central

    Elbelt, Ulf; Schuetz, Tatjana; Knoll, Nina; Burkert, Silke

    2015-01-01

    Reduced physical activity and almost unlimited availability of food are major contributors to the development of obesity. With the decline of strenuous work, energy expenditure due to spontaneous physical activity has attracted increasing attention. Our aim was to assess changes in energy expenditure, physical activity patterns and nutritional habits in obese subjects aiming at self-directed weight loss. Methods: Energy expenditure and physical activity patterns were measured with a portable armband device. Nutritional habits were assessed with a food frequency questionnaire. Results: Data on weight development, energy expenditure, physical activity patterns and nutritional habits were obtained for 105 patients over a six-month period from an initial cohort of 160 outpatients aiming at weight loss. Mean weight loss was −1.5 ± 7.0 kg (p = 0.028). Patients with weight maintenance (n = 75), with substantial weight loss (>5% body weight, n = 20) and with substantial weight gain (>5% body weight, n = 10) did not differ in regard to changes of body weight adjusted energy expenditure components (total energy expenditure: −0.2 kcal/kg/day; non-exercise activity thermogenesis: −0.3 kcal/kg/day; exercise-related activity thermogenesis (EAT): −0.2 kcal/kg/day) or patterns of physical activity (duration of EAT: −2 min/day; steps/day: −156; metabolic equivalent unchanged) measured objectively with a portable armband device. Self-reported consumption frequency of unfavorable food decreased significantly (p = 0.019) over the six-month period. Conclusions: An increase in energy expenditure or changes of physical activity patterns (objectively assessed with a portable armband device) are not employed by obese subjects to achieve self-directed weight loss. However, modified nutritional habits could be detected with the use of a food frequency questionnaire. PMID:26193310

  3. Bifunctional enhancement of oxygen reduction reaction activity on Ag catalysts due to water activation on LaMnO3 supports in alkaline media

    PubMed Central

    Park, Shin-Ae; Lee, Eun-Kyung; Song, Hannah; Kim, Yong-Tae

    2015-01-01

    Ag is considered to be one of the best candidates for oxygen reduction reaction electrocatalysts in alkaline media for application in various electrochemical energy devices. In this study, we demonstrate that water activation is a key factor in enhancing the ORR activity in alkaline media, unlike in acid environments. Ag supported on LaMnO3 having a high oxophilicity showed a markedly higher ORR activity than that on carbon with inert surfaces. Through various electrochemical tests, it was revealed that the origin of the enhanced ORR activity of Ag/LaMnO3 is the bifunctional effect mainly due to the water activation at the interface between Ag and LaMnO3. Furthermore, the ligand effect due to the charge transfer from Mn to Ag leads to the enhancement of both oxygen activation on Ag and water activation on Mn sites, and hence, an improvement in the ORR activity of Ag/LaMnO3. On the other hand, the strain effect based on the fine structure variation in the lattice was negligible. We therefore suggest that the employment of a co-catalyst or support with highly oxophilic nature and the maximization of the interface between catalyst and support should be considered in the design of electrocatalysts for the ORR in alkaline media. PMID:26310526

  4. An Investigation of Activity Profiles of Older Adults

    PubMed Central

    Putnam, Michelle; Lee, Yung Soo; Greenfield, Jennifer C.; Inoue, Megumi; Chen, Huajuan

    2014-01-01

    Objectives. In this study, we advance knowledge about activity engagement by considering many activities simultaneously to identify profiles of activity among older adults. Further, we use cross-sectional data to explore factors associated with activity profiles and prospective data to explore activity profiles and well-being outcomes. Method. We used the core survey data from the years 2008 and 2010, as well as the 2009 Health and Retirement Study Consumption and Activities Mail Survey (HRS CAMS). The HRS CAMS includes information on types and amounts of activities. We used factor analysis and latent class analysis to identify activity profiles and regression analyses to assess antecedents and outcomes associated with activity profiles. Results. We identified 5 activity profiles: Low Activity, Moderate Activity, High Activity, Working, and Physically Active. These profiles varied in amount and type of activities. Demographic and health factors were related to profiles. Activity profiles were subsequently associated with self-rated health and depression symptoms. Discussion. The use of a 5-level categorical activity profile variable may allow more complex analyses of activity that capture the “whole person.” There is clearly a vulnerable group of low-activity individuals as well as a High Activity group that may represent the “active ageing” vision. PMID:24526690

  5. The study of variations of low energy cosmic helium's flux (up to 6 MeV) due to solar activity

    NASA Astrophysics Data System (ADS)

    Shayan, M.; Davoudifar, P.; Bagheri, Z.

    2017-04-01

    In General, the flux of low energy cosmic rays varies with time due to solar activities. The cosmic particle fluxes were studied using data of satellites near the Earth. In this work, first we studied the variations of particle fluxes from 1 Jan to 31 Dec 2000 and 35 events were selected. Then we proposed a relation for cosmic particle flux as a function of time and rigidity in the time of approaching ejecta to the Earth. The coefficients of the relation were calculated using experimental data of particle fluxes from ACE satellite. Finally, we compare time variations of these coefficients for different events.

  6. Investigate the Child's Scientific Activities on Practical Child's Activity Books for the Kindergarten's Children

    ERIC Educational Resources Information Center

    Aldarabah, Intisar Turki; Al-Mouhtadi, Reham

    2015-01-01

    This research aimed to investigate the extent to which the interactive international curriculum is included in the "Child's Scientific Activities" issued by the Ministry of Education in Jordan, for the kindergarten stage according to the global criterion (NRC). In order to answer the study questions, an instrument was developed to…

  7. (-)-1-(Benzofuran-2-yl)-2-propylaminopentane enhances locomotor activity in rats due to its ability to induce dopamine release.

    PubMed

    Shimazu, S; Takahata, K; Katsuki, H; Tsunekawa, H; Tanigawa, A; Yoneda, F; Knoll, J; Akaike, A

    2001-06-15

    "Catecholaminergic and serotoninergic activity enhancer" effects are newly found mechanisms of action of a class of compound that enhance impulse propagation-mediated release of catecholamines and serotonin in the brain. In the present study, (-)-1-(benzofuran-2-yl)-2-propylaminopentane hydrochloride [(-)-BPAP HCl], a compound with selective and potent "catecholaminergic and serotoninergic activity enhancer" effects, was tested for its efficacy to potentiate locomotor activity in normal rats and to attenuate hypolocomotion in reserpine-treated rats. (-)-BPAP HCl potentiated locomotor activity in non-habituated rats during a 2-h observation period dose-dependently (0.3-10 mg/kg). (-)-BPAP HCl (1-3 mg/kg) was also effective to reverse reserpine-induced hypolocomotion. The effects of (-)-BPAP HCl in normal and reserpine-treated rats were attenuated by the dopamine D1 receptor antagonist, R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SCH 23390), suggesting that the effects of (-)-BPAP HCl were mediated by activation of the dopaminergic system. In addition, the administration of (-)-BPAP HCl increased ipsilateral turning in unilaterally 6-hydroxydopamine-lesioned rats, implying presynaptic activation of nigrostriatal dopaminergic terminals by (-)-BPAP HCl. Furthermore, although antiparkinsonian agents, such as apomorphine and amantadine, failed to improve reserpine-induced ptosis, (-)-BPAP HCl significantly improved ptosis. These findings suggested that a "catecholaminergic and serotoninergic activity enhancer" compound, (-)-BPAP, stimulates motor function in rats and improves motor deficits in animal models of Parkinson's disease due to its ability to induce dopamine release.

  8. Enhanced photocatalytic activity of ultra-high aspect ratio ZnO nanowires due to Cu induced defects

    NASA Astrophysics Data System (ADS)

    Pasupathi Sugavaneshwar, Ramu; Duy Dao, Thang; Nanda, Karuna Kar; Nagao, Tadaaki; Hishita, Shunichi; Sakaguchi, Isao

    2015-12-01

    We report the synthesis of ZnO nanowires in ambient air at 650°C by a single-step vapor transport method using two different sources Zn (ZnO nanowires-I) and Zn:Cu (ZnO nanowires-II). The Zn:Cu mixed source co-vaporize Zn with a small amount of Cu at temperatures where elemental Cu source does not vaporize. This method provides us a facile route for Cu doping into ZnO. The aspect ratio of the grown ZnO nanowires-II was found to be higher by more than five times compared ZnO nanowires-I. Photocatalytic activity was measured by using a solar simulator and its ultraviolet-filtered light. The ZnO nanowires-II shows higher catalytic activity due to increased aspect ratio and higher content of surface defects because of incorporation of Cu impurities.

  9. Mechanistic investigation of beta-galactosidase-activated MR contrast agents.

    PubMed

    Urbanczyk-Pearson, Lauren M; Femia, Frank J; Smith, Jeffrey; Parigi, Giacomo; Duimstra, Joseph A; Eckermann, Amanda L; Luchinat, Claudio; Meade, Thomas J

    2008-01-07

    We report a mechanistic investigation of an isomeric series of beta-galactosidase-activated magnetic resonance contrast agents. Our strategy focuses on the synthesis of macrocyclic caged-complexes that coordinatively saturate a chelated lanthanide. Enzyme cleavage of the complex results in an open coordination site available for water that creates a detectable MR contrast agent. The complexes consist of a DO3A Gd(III) chelator modified with a galactopyranose at the N-10 position of the macrocycle. We observed significant differences in relaxometric properties and coordination geometry that can be correlated to subtle variations of the linker between the macrocycle and the galactopyranose. After synthesis and purification of the R, S, and racemic mixtures of complexes 1 and 3 and measurement of the hydration number, water residence lifetime, and longitudinal relaxation rates, we propose mechanisms for water exclusion from the lanthanide in the precleavage state. While the stereochemistry of the linker does not influence the agents' properties, the mechanism of water exclusion for each isomer is significantly influenced by the position of modification. Data for one series with a methyl group substituted on the sugar-macrocycle linker at the alpha-position suggests a steric mechanism where the galactopyranose sugar blocks water from the Gd(III) center. In contrast, our observations for a second series with methyl substitution at the beta position of the sugar-macrocycle linker are consistent with a mechanism in which a bidentate anion occupies two available coordination sites of Gd(III) in the precleavage state.

  10. Theory, Investigation and Stability of Cathode Electrocatalytic Activity

    SciTech Connect

    Ding, Dong; Liu, Mingfei; Lai, Samson; Blinn, Kevin; Liu, Meilin

    2012-09-30

    conditions. This was also confirmed by x-ray analyses. For example, soft x-ray XANES data reveal that Co cations displace the Mn cations as being more favored to be reduced. Variations in the Sr-O in the annealed LSCF Fourier-transformed (FT) EXAFS suggest that some Sr segregation is occurring, but is not present in the annealed LSM-infiltrated LSCF cathode materials. Further, a surface enhanced Raman technique was also developed into to probe and map LSM and LSCF phase on underlying YSZ substrate, enabling us to capture important chemical information of cathode surfaces under practical operating conditions. Electrochemical models for the design of test cells and understanding of mechanism have been developed for the exploration of fundamental properties of electrode materials. Novel catalyst coatings through particle depositions (SDC, SSC, and LCC) or continuous thin films (PSM and PSCM) were successfully developed to improve the activity and stability of LSCF cathodes. Finally, we have demonstrated enhanced activity and stability of LSCF cathodes over longer periods of time in homemade and commercially available cells by an optimized LSM infiltration process. Microstructure examination of the tested cells did not show obvious differences between blank and infiltrated cells, suggesting that the infiltrated LSM may form a coherent film on the LSCF cathodes. There was no significant change in the morphology or microstructure of the LSCF cathode due to the structural similarity of LSCF and LSM. Raman analysis of the tested cells indicated small peaks emerging on the blank cells that correspond to trace amounts of secondary phase formation during operation (e.g., CoO{sub x}). The formation of this secondary phase might be attributed to performance degradation. In contrast, there was no such secondary phase observed in the LSM infiltrated cells, indicating that the LSM modification staved off secondary phase formation and thus improved the stability.

  11. On the variation of the ionospheric potential due to large-scale radioactivity enhancement and solar activity

    NASA Astrophysics Data System (ADS)

    Slyunyaev, Nikolay N.; Mareev, Evgeny A.; Zhidkov, Artem A.

    2015-08-01

    Sensitivity of the global electric circuit (GEC) to variations of atmospheric conductivity and current sources is analyzed and discussed. When the undisturbed exponential conductivity profile is assumed all over the Earth, the most substantial changes in the ionospheric potential (IP) are caused by conductivity perturbations inside thunderstorms; if, in addition, conductivity reduction inside thunderstorms and nonelectrified clouds is assumed, the IP becomes less sensitive to conductivity perturbations; besides, the IP is even more sensitive to source current variations than to conductivity. Current source and voltage source descriptions of GEC generators are compared; it is shown that the IP variation may critically depend on the chosen description. As an application, the IP variation due to nuclear weapons testing is studied; it is shown that neither local nor global increase of conductivity in the stratosphere could alone explain the observed 40% IP increase in the 1960s; at the same time this increase might be accounted for by a 40% increase in the source current density or a 46% reduction of the conductivity inside thunderstorms, provided that it was not reduced initially. The IP variation due to solar activity and, in particular, due to solar modulation of galactic cosmic ray flux is also discussed and modeled, which required an adequate parameterization of the rate of atmospheric ion pair production over the solar cycle. It is estimated that the maximum IP variation on the scale of the solar cycle does not exceed 5% of the mean value, unless source current perturbations are taken into account.

  12. The Use of LS-DYNA in the Columbia Accident Investigation and Return to Flight Activities

    NASA Technical Reports Server (NTRS)

    Gabrys, Jonathan; Schatz, Josh; Carney, Kelly; Melis, Matthew; Fasanella, Edwin L.; Lyle, Karen H.

    2004-01-01

    During the launch of the Space Shuttle Columbia on January 16, 2003, foam originating from the external tank impacted the shuttle's left wing 81 seconds after lift-off. Then on February 1st, Space Shuttle Columbia broke-up during re-entry. In the weeks that followed, the Columbia Accident Investigation Board had formed various teams to investigate every aspect of the tragedy. One of these teams was the Impact Analysis Team, which was asked to investigate the foam impact on the wing leading edge. This paper will describe the approach and methodology used by the team to support the accident investigation, and more specifically the use of LS-DYNA for analyzing the foam impact event. Due to the success of the analytical predictions, the impact analysis team has also been asked to support Return to Flight activities. These activities will analyze a far broader range of impact events, but not with just foam and not only on the wing leading edge. The debris list has expanded and so have the possible impact locations. This paper will discuss the Return to Flight activities and the use of LS-DYNA to support them.

  13. Depletion of NADP(H) due to CD38 activation triggers endothelial dysfunction in the postischemic heart

    PubMed Central

    Reyes, Levy A.; Boslett, James; Varadharaj, Saradhadevi; De Pascali, Francesco; Hemann, Craig; Druhan, Lawrence J.; Ambrosio, Giuseppe; El-Mahdy, Mohamed; Zweier, Jay L.

    2015-01-01

    In the postischemic heart, coronary vasodilation is impaired due to loss of endothelial nitric oxide synthase (eNOS) function. Although the eNOS cofactor tetrahydrobiopterin (BH4) is depleted, its repletion only partially restores eNOS-mediated coronary vasodilation, indicating that other critical factors trigger endothelial dysfunction. Therefore, studies were performed to characterize the unidentified factor(s) that trigger endothelial dysfunction in the postischemic heart. We observed that depletion of the eNOS substrate NADPH occurs in the postischemic heart with near total depletion from the endothelium, triggering impaired eNOS function and limiting BH4 rescue through NADPH-dependent salvage pathways. In isolated rat hearts subjected to 30 min of ischemia and reperfusion (I/R), depletion of the NADP(H) pool occurred and was most marked in the endothelium, with >85% depletion. Repletion of NADPH after I/R increased NOS-dependent coronary flow well above that with BH4 alone. With combined NADPH and BH4 repletion, full restoration of NOS-dependent coronary flow occurred. Profound endothelial NADPH depletion was identified to be due to marked activation of the NAD(P)ase-activity of CD38 and could be prevented by inhibition or specific knockdown of this protein. Depletion of the NADPH precursor, NADP+, coincided with formation of 2’-phospho-ADP ribose, a CD38-derived signaling molecule. Inhibition of CD38 prevented NADP(H) depletion and preserved endothelium-dependent relaxation and NO generation with increased recovery of contractile function and decreased infarction in the postischemic heart. Thus, CD38 activation is an important cause of postischemic endothelial dysfunction and presents a novel therapeutic target for prevention of this dysfunction in unstable coronary syndromes. PMID:26297248

  14. ROSAT investigation of flaring and activity on Prox Cen

    NASA Technical Reports Server (NTRS)

    Haisch, Bernhard

    1993-01-01

    The objective of this program was to investigate with high sensitivity the low-level flare activity which may underlie coronal heating. This was done. The ROSAT observations of Prox Cen were scheduled for 50 ks spread out from 26 Feb. - 10 Mar. 1992. Unfortunately because of spacecraft problems many of these pointings turned out to contain no useful data or extremely truncated valid data sets. Considerable time was spent trying to determine which of the data would be scientifically useful and which would not. Fortunately, several developments took place to augment the original data in such a way that the scientific goal of advancing the study of flaring and variability was able to be achieved after all. These are as follows: (1) a second round of ROSAT observations was carried out in Feb. 1993 which only came to the attention of the PI in Apr. 1993 when a new data tape arrived; (2) simultaneous IUE observations were requested and obtained; (3) data from the UK WFC are available via the collaboration with Dr. G. Bromage; and (4) the 'cleaned-up' original data set was found to include one major flare and 2 moderate flares. Because of the problems with the original data set, the unexpected acquisition of new data only two months ago, and the availability of IUE and WFC data, an article on Prox Cen for publication is not ready at this time. Such an article is being developed and can be completed as part of ongoing ROSAT research efforts on stellar coronae and flaring.

  15. Active hydrothermal and non-active massive sulfide mound investigation using a new multiparameter chemical sensor

    NASA Astrophysics Data System (ADS)

    Han, C.; Wu, G.; Qin, H.; Wang, Z.

    2012-12-01

    Investigation of active hydrothermal mound as well as non-active massive sulfide mound are studied recently. However, there is still lack of in-situ detection method for the non-active massive sulfide mound. Even though Transient ElectroMagnetic (TEM) and Electric Self-potential (SP) methods are good, they both are labour, time and money cost work. We proposed a new multiparameter chemical sensor method to study the seafloor active hydrothermal mound as well as non-active massive sulfide mound. This sensor integrates Eh, S2- ions concentration and pH electrochemical electrodes together, and could found chemical change caused by the active hydrothermal vent, even weak chemical abnormalities by non-active massive sulfide hydrothermal mound which MARP and CTD sometimes cannot detect. In 2012, the 1st Leg of the Chinese 26th cruise, the multiparameter chemical sensor was carried out with the deepsea camera system over the Carlsberg Ridge in Indian Ocean by R/V DAYANGYIHAO. It was shown small Eh and S2- ions concentration abnormal around a site at Northwest Indian ridge. This site was also evidenced by the TV grab. In the 2nd Leg of the same cruise in June, this chemical sensor was carried out with TEM and SP survey system. The chemical abnormalities are matched very well with both TEM and SP survey results. The results show that the multiparameter chemical sensor method not only can detect active hydrothermal mound, but also can find the non-active massive sulfide hydrothermal mound.

  16. Active infective endocarditis due to Erysipelothrix rhusiopathiae: zoonosis caused by vancomycin-resistant gram-positive rod.

    PubMed

    Miura, Takashi; Hashizume, Koji; Ariyoshi, Tsuneo; Miwa, Takashi; Furumoto, Akitsugu; Izumida, Mai; Yanagihara, Katsunori; Eishi, Kiyoyuki

    2013-02-01

    A 42-year-old female who was a voluntary worker in a school for handicapped children was referred to us for surgery for active infective endocarditis. Trans-esophageal echocardiography showed 2 large mobile vegetations on the aortic valve and severe aortic regurgitation. Aortic valve replacement was performed to prevent septic embolism and deterioration of congestive heart failure. The empiric therapy with vancomycin, ampicillin, and gentamycin was initiated because a pathogen was not identified. But Erysipelothrix rhusiopathiae (gram-positive rod) was isolated on the 4th day after surgery. The target therapy with penicillin G and clindamycin was started and continued for 4 weeks after surgery. The inflammatory parameters improved steadily and the patient was discharged on the 36th day after surgery. Infective endocarditis due to gram-positive rods can be easily mistaken for streptococci or dismissed as a skin contamination. But, E. rhusiopathiae endocarditis should be considered in the differential diagnosis.

  17. Differential activity in Heschl's gyrus between deaf and hearing individuals is due to auditory deprivation rather than language modality.

    PubMed

    Cardin, Velia; Smittenaar, Rebecca C; Orfanidou, Eleni; Rönnberg, Jerker; Capek, Cheryl M; Rudner, Mary; Woll, Bencie

    2016-01-01

    Sensory cortices undergo crossmodal reorganisation as a consequence of sensory deprivation. Congenital deafness in humans represents a particular case with respect to other types of sensory deprivation, because cortical reorganisation is not only a consequence of auditory deprivation, but also of language-driven mechanisms. Visual crossmodal plasticity has been found in secondary auditory cortices of deaf individuals, but it is still unclear if reorganisation also takes place in primary auditory areas, and how this relates to language modality and auditory deprivation. Here, we dissociated the effects of language modality and auditory deprivation on crossmodal plasticity in Heschl's gyrus as a whole, and in cytoarchitectonic region Te1.0 (likely to contain the core auditory cortex). Using fMRI, we measured the BOLD response to viewing sign language in congenitally or early deaf individuals with and without sign language knowledge, and in hearing controls. Results show that differences between hearing and deaf individuals are due to a reduction in activation caused by visual stimulation in the hearing group, which is more significant in Te1.0 than in Heschl's gyrus as a whole. Furthermore, differences between deaf and hearing groups are due to auditory deprivation, and there is no evidence that the modality of language used by deaf individuals contributes to crossmodal plasticity in Heschl's gyrus.

  18. 3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) produces edema due to BBB disruption induced by MMP-9 activation in rat hippocampus.

    PubMed

    Pérez-Hernández, Mercedes; Fernández-Valle, María Encarnación; Rubio-Araiz, Ana; Vidal, Rebeca; Gutiérrez-López, María Dolores; O'Shea, Esther; Colado, María Isabel

    2017-03-16

    The recreational drug of abuse, 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) disrupts blood-brain barrier (BBB) integrity in rats through an early P2X7 receptor-mediated event which induces MMP-9 activity. Increased BBB permeability often causes plasma proteins and water to access cerebral tissue leading to vasogenic edema formation. The current study was performed to examine the effect of a single neurotoxic dose of MDMA (12.5 mg/kg, i.p.) on in vivo edema development associated with changes in the expression of the perivascular astrocytic water channel, AQP4, as well as in the expression of the tight-junction (TJ) protein, claudin-5 and Evans Blue dye extravasation in the hippocampus of adult male Dark Agouti rats. We also evaluated the ability of the MMP-9 inhibitor, SB-3CT (25 mg/kg, i.p.), to prevent these changes in order to validate the involvement of MMP-9 activation in MDMA-induced BBB disruption. The results show that MDMA produces edema of short duration temporally associated with changes in AQP4 expression and a reduction in claudin-5 expression, changes which are prevented by SB-3CT. In addition, MDMA induces a short-term increase in both tPA activity and expression, a serine-protease which is involved in BBB disruption and upregulation of MMP-9 expression. In conclusion, this study provides evidence enough to conclude that MDMA induces edema of short duration due to BBB disruption mediated by MMP-9 activation.

  19. [Investigation of the present management status of calibration source based on the law concerning prevention of radiation hazards due to radioisotopes].

    PubMed

    Takahashi, Yasuyuki; Igarashi, Hiroshi; Hirano, Kunihiro; Kawaharada, Yasuhiro; Igarashi, Hitoshi; Murase, Ken-ya; Mochizuki, Teruhito

    2007-03-20

    An amendment concerning the enforcement of the law on the prevention of radiation hazards due to radioisotopes, etc., and the medical service law enforcement regulations were promulgated on June 1, 2005. This amendment concerned international basic safety standards and the sealing of radiation sources. Sealed radiation sources < or =3.7 MBq, which had been excluded from regulation, were newly included as an object of regulation. Investigation of the SPECT system instituted in hospitals indicated that almost all institutions adhere to the new amendment, and the calibration source, the checking source, etc., corresponding to this amendment were maintained appropriately. Any institutions planning to return sealed radioisotopes should refer to this report.

  20. Molecular structure activity on pharmaceutical applications of Phenacetin using spectroscopic investigation

    NASA Astrophysics Data System (ADS)

    Madanagopal, A.; Periandy, S.; Gayathri, P.; Ramalingam, S.; Xavier, S.

    2017-01-01

    The pharmaceutical compound; Phenacetin was investigated by analyzing FT-IR, FT-Raman and 1H &13C NMR spectra. The hybrid efficient computational calculations performed for computing physical and chemical parameters. The cause of pharmaceutical activity due to the substitutions; carboxylic, methyl and amine groups in appropriate positions on the pedestal compound was deeply investigated. Moreover, 13C NMR and 1H NMR chemical shifts correlated with TMS standard to explain the truth of compositional ratio of base and ligand groups. The bathochromic shift due to chromophores over the energy levels in UV-Visible region was strongly emphasized the Anti-inflammatory chemical properties. The chemical stability was pronounced by the strong kubo gap which showed the occurring of charge transformation within the molecule. The occurrence of the chemical reaction was feasibly interpreted by Gibbs free energy profile. The standard vibrational analysis stressed the active participation of composed ligand groups for the existence of the analgesic as well as antipyretic properties of the Phenacetin compound. The strong dipole interaction energy utilization for the transition among non-vanishing donor and acceptor for composition of the molecular structure was interpreted.

  1. Investigation of photocalalytic activity of ZnO prepared by spray pyrolis with various precursors

    NASA Astrophysics Data System (ADS)

    Bourfaa, F.; Lamri Zeggar, M.; A, A.; Aida, M. S.; Attaf, N.

    2016-03-01

    Semiconductor photocatalysts such as ZnO has attracted much attention in recent years due to their various applications for the degradation of organic pollutants in water, air and in dye sensitized photovoltaic solar cell. In the present work, ZnO thin films were prepared by ultrasonic spray pyrolysis by using different precursors namely: acetate, chloride and zinc nitrate in order to investigate their influence on ZnO photocatalytic activity. The films crystalline structure was studied by mean of X- ray diffraction measurements (XRD) and the films surface morphology by Scanning Electron Microscopy (SEM). The films optical properties were studied by mean of UV-visible spectroscopy. The prepared films were tested for the degradation of the red reactive dye largely used in textile industry. As a result, we found that the zinc nitrate is the best precursor to prepare ZnO thin films suitable for a good photocatalytic activity.

  2. Investigating the Jack the Ripper Case: Engaging Students in a Criminal Investigations Class through Active Learning

    ERIC Educational Resources Information Center

    Gutierrez, Daniel; Kazmi, Syed

    2010-01-01

    The present study examines the utilization of a class project involving the Jack the Ripper murders. Students enrolled in a criminal investigations class were required to investigate the five canonical murders associated with the infamous serial killer known as Jack the Ripper and the murders that occurred in London during 1888. This paper…

  3. Delayed glial clearance of degenerating axons in aged Drosophila is due to reduced PI3K/Draper activity

    PubMed Central

    Purice, Maria D.; Speese, Sean D.; Logan, Mary A.

    2016-01-01

    Advanced age is the greatest risk factor for neurodegenerative disorders, but the mechanisms that render the senescent brain vulnerable to disease are unclear. Glial immune responses provide neuroprotection in a variety of contexts. Thus, we explored how glial responses to neurodegeneration are altered with age. Here we show that glia–axon phagocytic interactions change dramatically in the aged Drosophila brain. Aged glia clear degenerating axons slowly due to low phosphoinositide-3-kinase (PI3K) signalling and, subsequently, reduced expression of the conserved phagocytic receptor Draper/MEGF10. Importantly, boosting PI3K/Draper activity in aged glia significantly reverses slow phagocytic responses. Moreover, several hours post axotomy, early hallmarks of Wallerian degeneration (WD) are delayed in aged flies. We propose that slow clearance of degenerating axons is mechanistically twofold, resulting from deferred initiation of axonal WD and reduced PI3K/Draper-dependent glial phagocytic function. Interventions that boost glial engulfment activity, however, can substantially reverse delayed clearance of damaged neuronal debris. PMID:27647497

  4. Investigation of oxidation process of mechanically activated ultrafine iron powders

    NASA Astrophysics Data System (ADS)

    Lysenko, E. N.; Nikolaev, E. V.; Vlasov, V. A.; Zhuravkov, S. P.

    2016-02-01

    The oxidation of mechanically activated ultrafine iron powders was studied using X- ray powder diffraction and thermogravimetric analyzes. The powders with average particles size of 100 nm were made by the electric explosion of wire, and were subjected to mechanical activation in planetary ball mill for 15 and 40 minutes. It was shown that a certain amount of FeO phase is formed during mechanical activation of ultrafine iron powders. According to thermogravimetric analysis, the oxidation process of non-milled ultrafine iron powders is a complex process and occurs in three stages. The preliminary mechanical activation of powders considerably changes the nature of the iron powders oxidation, leads to increasing in the temperature of oxidation onset and shifts the reaction to higher temperatures. For the milled powders, the oxidation is more simple process and occurs in a single step.

  5. Optical Modeling Activities for NASA's James Webb Space Telescope (JWST). 3; Wavefront Aberrations due to Alignment and Figure Compensation

    NASA Technical Reports Server (NTRS)

    Howard, Joseph

    2007-01-01

    This is part three of a series describing the ongoing optical modeling activities for James Webb Space Telescope (JWST). The first two discussed modeling JWST on-orbit performance using wavefront sensitivities to predict line of sight motion induced blur, and stability during thermal transients. The work here investigates the aberrations resulting from alignment and figure compensation of the controllable degrees of freedom (primary and secondary mirrors), which may be encountered during ground alignment and on-orbit commissioning of the observatory. The optical design of the telescope is a three-mirror anastigmat, with an active fold mirror at the exit pupil for fine guiding. The primary mirror is over 6.5 meters in diameter, and is composed of 18 hexagonal segments that can individually positioned on hexapods, as well as compensated for radius of curvature. This effectively gives both alignment and figure control of the primary mirror. The secondary mirror can be moved in rigid body only, giving alignment control of the telescope. The tertiary mirror is fixed, however, as well as the location of the science instrumentation. Simulations are performed of various combinations of active alignment corrections of component figure errors, and of primary mirror figure corrections of alignment errors. Single field point and moderate field knowledge is assumed in the corrections. Aberrations over the field are reported for the varying cases, and examples presented.

  6. An Investigation of Implicit Active Contours for Scientific Image Segmentation

    SciTech Connect

    Weeratunga, S K; Kamath, C

    2003-10-29

    The use of partial differential equations in image processing has become an active area of research in the last few years. In particular, active contours are being used for image segmentation, either explicitly as snakes, or implicitly through the level set approach. In this paper, we consider the use of the implicit active contour approach for segmenting scientific images of pollen grains obtained using a scanning electron microscope. Our goal is to better understand the pros and cons of these techniques and to compare them with the traditional approaches such as the Canny and SUSAN edge detectors. The preliminary results of our study show that the level set method is computationally expensive and requires the setting of several different parameters. However, it results in closed contours, which may be useful in separating objects from the background in an image.

  7. Investigation of active-buffer pulse tube refrigerator

    NASA Astrophysics Data System (ADS)

    Zhu, Shaowei; Kakimi, Yasuhiro; Matsubara, Yoichi

    An active-buffer pulse tube refrigerator, which is a GM type pulse tube refrigerator, is described in this paper. Two or more buffers are connected at the hot end of the pulse tube through on/off valves. The main purpose of this method is to increase the efficiency. A numerical method is introduced to analyse the working process. To understand the basic mechanism, an ideal cycle is also introduced. With a prototype single stage active-buffer pulse tube refrigerator, a cooling capacity of 166 W and a percent Carnot of 13% at 80 K have been obtained.

  8. Mitochondrial apoptotic pathway activation in the atria of heart failure patients due to mitral and tricuspid regurgitation.

    PubMed

    Chang, Jen-Ping; Chen, Mien-Cheng; Liu, Wen-Hao; Lin, Yu-Sheng; Huang, Yao-Kuang; Pan, Kuo-Li; Ho, Wan-Chun; Fang, Chih-Yuan; Chen, Chien-Jen; Chen, Huang-Chung

    2015-08-01

    . Immunoblotting of atrial extracts showed that there was enhanced expression of cytosolic cytochrome c, an effector of the mitochondrial pathways, but no expression of membrane TRADD and cytosolic caspase-8 in the right atrial tissue of mitral and tricuspid regurgitation patients with sinus rhythm, and right atrial and left atrial tissues of mitral and tricuspid regurgitation patients with atrial fibrillation. Taken together, this study showed that mitochondrial pathway for apoptosis was activated in the right atria in sinus rhythm and in the left and right atria in atrial fibrillation of heart failure patients due to mitral and tricuspid regurgitation, and this mitochondrial pathway activation may contribute to atrial contractile dysfunction and enlargement in this clinical setting.

  9. Synthesis, molecular structure investigations and antimicrobial activity of 2-thioxothiazolidin-4-one derivatives

    NASA Astrophysics Data System (ADS)

    Barakat, Assem; Al-Najjar, Hany J.; Al-Majid, Abdullah Mohammed; Soliman, Saied M.; Mabkhot, Yahia Nasser; Al-Agamy, Mohamed H. M.; Ghabbour, Hazem A.; Fun, Hoong-Kun

    2015-02-01

    A variety of 2-thioxothiazolidin-4-one derivatives were prepared and their in vitro antimicrobial activities were studied. Most of these compounds showed significant antibacterial activity specifically against Gram-positive bacteria, among which compounds 4a,e,g, 5b,e,g,h and 6f exhibit high levels of antimicrobial activity against Bacillus subtilis ATCC 10400 with Minimum Inhibitory Concentration (MIC) value of 16 μg/mL. All compounds have antifungal activity against Candida albicans. Unfortunately, however, none of the compounds were active against Gram-negative bacteria. The chemical structure of 3 was confirmed by X-ray single crystal diffraction technique. DFT calculations of 3 have been performed on the free C10H7Cl2NO2S2, 3a and the H-bonded complex, C10H7Cl2NO2S2·H2O, 3b to explore the effect of the H-bonding interactions on the geometric and electronic properties of the studied systems. A small increase in bond length was observed in the C12-O6 due to the H-bonding interactions between 3a and water molecule. MEP study has been used to recognize the most reactive sites towards electrophilic and nucleophilic attacks as well as the possible sites for the H-bonding interactions. The TD-DFT calculations have been used to predict theoretically the electronic spectra of the studied compound. The most intense transition band is predicted at 283.9 nm due to the HOMO-2/HOMO-1 to LUMO transitions. NBO analyses were carried out to investigate the stabilization energy of the various intramolecular charge transfer interactions within the studied molecules.

  10. Evolution & Phylogenetic Analysis: Classroom Activities for Investigating Molecular & Morphological Concepts

    ERIC Educational Resources Information Center

    Franklin, Wilfred A.

    2010-01-01

    In a flexible multisession laboratory, students investigate concepts of phylogenetic analysis at both the molecular and the morphological level. Students finish by conducting their own analysis on a collection of skeletons representing the major phyla of vertebrates, a collection of primate skulls, or a collection of hominid skulls.

  11. STRUCTURE-ACTIVITY RELATIONSHIP STUIDES AND THEIR ROLE IN PREDICTING AND INVESTIGATING CHEMICAL TOXICITY

    EPA Science Inventory

    Structure-Activity Relationship Studies and their Role in Predicting and Investigating Chemical Toxicity

    Structure-activity relationships (SAR) represent attempts to generalize chemical information relative to biological activity for the twin purposes of generating insigh...

  12. Our Economy: How It Works. Activities and Investigation. Teacher's Edition.

    ERIC Educational Resources Information Center

    Clawson, Elmer U.

    To help junior and senior high school students develop a better understanding of the United States' economy, this teacher's guide presents a series of learning activities centered around eight general themes. The topics (corresponding to the document's eight chapters) include both international and global economic issues as well as current…

  13. Designing the Perfect Plant: Activities to Investigate Plant Ecology

    ERIC Educational Resources Information Center

    Lehnhoff, Erik; Woolbaugh, Walt; Rew, Lisa

    2008-01-01

    Plant ecology is an important subject that often receives little attention in middle school, as more time during science classes is devoted to plant biology. Therefore, the authors have developed a series of activities, including a card game--Designing the Perfect Plant--to introduce student's to plant ecology and the ecological trade offs…

  14. Recess Physical Activity Packs in Elementary Schools: A Qualitative Investigation

    ERIC Educational Resources Information Center

    Elliott, Steven; Combs, Sue; Boyce, Robert

    2011-01-01

    To supplement the present weekly allotment of 30 minutes of physical education, a school district in southeastern North Carolina identified recess time as part of the state mandated (HSP-S-000) 150 minutes of physical activity (PA) per week and have purchased fitness equipment (recess packs) for the children to use. Twelve participants were…

  15. Development and Pilot Investigation of Behavioral Activation for Negative Symptoms

    ERIC Educational Resources Information Center

    Mairs, Hilary; Lovell, Karina; Campbell, Malcolm; Keeley, Philip

    2011-01-01

    Negative symptoms cause functional impairment and impede recovery from psychosis, not least, because of limited developments in empirically validated treatments. This article details a pilot evaluation of a behavioral activation (BA) treatment with eight people presenting with psychosis and marked negative symptoms. The rationale for this…

  16. Response of the turbidity maximum zone in the Yangtze River Estuary due to human activities during the dry season.

    PubMed

    Chen, Xiaofeng; Shen, Zhenyao; Yang, Ye

    2016-09-01

    The interaction between a river and the sea results in a turbidity maximum zone (TMZ) within the estuary, which has a great impact on the local ecosystem. In the Yangtze River Estuary, the magnitude and extent of the TMZ vary with water discharge. In this study, the cumulative human activity altered the water discharge regime from the river to the estuary. In the post-Three Gorges Dam (TGD) period, water discharge increased by 35.10 % at Datong in February compared with that in the pre-TGD period. The effects of water discharge variation on the characteristics of the TMZ were analyzed during spring and neap tidal periods using the three-dimensional environmental fluid dynamic code (EFDC) model. The area of the TMZ decreased by 3.11 and 17.39 % during neap and spring tides, respectively. In addition, the upper limit of the TMZ moved 11.68 km seaward during neap tide, whereas the upper limit of the TMZ in the upstream and downstream areas moved seaward 9.65 and 2.34 km, respectively, during spring tide. These findings suggest that the area and location of the TMZ are more sensitive to upstream runoff during spring tide than during neap tide. These changes in the TMZ will impact the biochemical processes in the Yangtze River Estuary. In the foreseeable future, the distribution characteristic of TMZ will inevitably change due to variations in the Yangtze River discharge resulting from new human activities (i.e., new dams), which are being constructed upstream in the Yangtze River system.

  17. In vitro anti-Helicobacter pylori activity of the probiotic strain Bacillus subtilis 3 is due to secretion of antibiotics.

    PubMed

    Pinchuk, I V; Bressollier, P; Verneuil, B; Fenet, B; Sorokulova, I B; Mégraud, F; Urdaci, M C

    2001-11-01

    A limited number of antibiotics can be used against Helicobacter pylori infection, and resistance jeopardizes the success of treatment. Therefore, a search for new agents is warranted. The use of probiotics to enhance gastrointestinal health has been proposed for many years, but the scientific basis of the prophylactic and therapeutic actions of probiotics has not yet been clearly delineated. Probiotic strain Bacillus subtilis 3, whose safety has previously been demonstrated, is known to have antagonistic properties against species of the family Enterobacteriaceae. In the present study, it was also found to inhibit H. pylori. The anti-H. pylori activity present in the cell-free supernatant was not related to pH or organic acid concentration. It was heat stable and protease insensitive. At least two antibiotics, detected by thin-layer chromatography (R(f) values, 0.47 and 0.85, respectively) and confirmed by high-performance liquid chromatographic analysis, were found to be responsible for this anti-H. pylori activity. All H. pylori strains tested were sensitive to both compounds. One of these compounds was identified as amicoumacin A, an antibiotic with anti-inflammatory properties. MICs for H. pylori determined in solid and liquid media ranged between 1.7 and 6.8 microg/ml and 0.75 and 2.5 microg/ml, respectively. The underestimation of MICs determined in solid medium may be due to physicochemical instability of the antibiotic under these test conditions. An additive effect between amicoumacin A and the nonamicoumacin antibiotic against H. pylori was demonstrated.

  18. In Vitro Anti-Helicobacter pylori Activity of the Probiotic Strain Bacillus subtilis 3 Is Due to Secretion of Antibiotics

    PubMed Central

    Pinchuk, Irina V.; Bressollier, Philippe; Verneuil, Bernard; Fenet, Bernard; Sorokulova, Irina B.; Mégraud, Francis; Urdaci, Maria C.

    2001-01-01

    A limited number of antibiotics can be used against Helicobacter pylori infection, and resistance jeopardizes the success of treatment. Therefore, a search for new agents is warranted. The use of probiotics to enhance gastrointestinal health has been proposed for many years, but the scientific basis of the prophylactic and therapeutic actions of probiotics has not yet been clearly delineated. Probiotic strain Bacillus subtilis 3, whose safety has previously been demonstrated, is known to have antagonistic properties against species of the family Enterobacteriaceae. In the present study, it was also found to inhibit H. pylori. The anti-H. pylori activity present in the cell-free supernatant was not related to pH or organic acid concentration. It was heat stable and protease insensitive. At least two antibiotics, detected by thin-layer chromatography (Rf values, 0.47 and 0.85, respectively) and confirmed by high-performance liquid chromatographic analysis, were found to be responsible for this anti-H. pylori activity. All H. pylori strains tested were sensitive to both compounds. One of these compounds was identified as amicoumacin A, an antibiotic with anti-inflammatory properties. MICs for H. pylori determined in solid and liquid media ranged between 1.7 and 6.8 μg/ml and 0.75 and 2.5 μg/ml, respectively. The underestimation of MICs determined in solid medium may be due to physicochemical instability of the antibiotic under these test conditions. An additive effect between amicoumacin A and the nonamicoumacin antibiotic against H. pylori was demonstrated. PMID:11600371

  19. An investigation of the impact of selected prereading activities on student content learning through laboratory activities

    NASA Astrophysics Data System (ADS)

    Kass, Jesse (Shaya)

    This study investigated whether two prereading activities impacted student learning from hands-on science activities. The study was based on constructivist learning theory. Based on the work of Piaget, it was hypothesized that students who activated prior knowledge would learn more from the activities. Based on the work of Vygotsky it was hypothesized that students who talk more and write more would learn more from the activity. The K-W-L chart and anticipation guide strategies were used with eighth grade students at Graves Middle School in Whittier, California before learning about levers and convection currents. D. M. Ogle (1986) created the three-column K-W-L chart to have students activate prior knowledge. In the first column, the students write what they already know about a subject, in the second column, the students write what they want to know about the subject, and the students complete the third column after learning about a subject by writing answers to the questions that they asked in the second column. Duffelmeyer (1994) created the anticipation guide based on Herber's (1978) reasoning guide. In the anticipation guide, the teacher creates three or four sentences that convey the major ideas of the topic and the students either agree or disagree with the statements. After learning about the topic, students revisit their answers and decide if they were correct or incorrect and they must defend their choices. This research used the Solomon (1947) four-square design and compared both the experimental groups to a control group that simply discussed the concepts before completing the activity. The research showed no significant difference between the control group and either of the treatment groups. The reasons for the lack of significant differences are considered. It was hypothesized that since the students were unfamiliar with the prereading activities and did not have much experience with using either writing-to-learn or talking-to-learn strategies, the

  20. Higher concentrations of nanoscale zero-valent iron (nZVI) in soil induced rice chlorosis due to inhibited active iron transportation.

    PubMed

    Wang, Jie; Fang, Zhanqiang; Cheng, Wen; Yan, Xiaomin; Tsang, Pokeung Eric; Zhao, Dongye

    2016-03-01

    In this study, the effects of concentrations 0, 100, 250, 500, 750 and 1000 mg kg(-1) of nanoscale zero-valent iron (nZVI) on germination, seedlings growth, physiology and toxicity mechanisms were investigated. The results showed that nZVI had no effect on germination, but inhibited the rice seedlings growth in higher concentrations (>500 mg kg(-1) nZVI). The highest suppression rate of the length of roots and shoots reached 46.9% and 57.5%, respectively. The 1000mg kg(-1) nZVI caused the highest suppression rates for chlorophyll and carotenoids, at 91.6% and 85.2%, respectively. In addition, the activity of antioxidant enzymes was altered by the translocation of nanoparticles and changes in active iron content. Visible symptoms of iron deficiency were observed at higher concentrations, at which the active iron content decreased 61.02% in the shoots, but the active iron content not decreased in roots. Interestingly, the total and available amounts of iron in the soil were not less than those in the control. Therefore, the plants iron deficiency was not caused by (i) deficiency of available iron in the soil and (ii) restraint of the absorption that plant takes in the available iron, while induced by (ⅲ) the transport of active iron from the root to the shoot was blocked. The cortex tissues were seriously damaged by nZVI which was transported from soil to the root, these were proved by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). This current study shows that the mechanism of iron deficiency in rice seedling was due to transport of active iron from the root to the shoot blocked, which was caused by the uptake of nZVI.

  1. Ruthenium dihydroxybipyridine complexes are tumor activated prodrugs due to low pH and blue light induced ligand release.

    PubMed

    Hufziger, Kyle T; Thowfeik, Fathima Shazna; Charboneau, David J; Nieto, Ismael; Dougherty, William G; Kassel, W Scott; Dudley, Timothy J; Merino, Edward J; Papish, Elizabeth T; Paul, Jared J

    2014-01-01

    Ruthenium drugs are potent anti-cancer agents, but inducing drug selectivity and enhancing their modest activity remain challenging. Slow Ru ligand loss limits the formation of free sites and subsequent binding to DNA base pairs. Herein, we designed a ligand that rapidly dissociates upon irradiation at low pH. Activation at low pH can lead to cancer selectivity, since many cancer cells have higher metabolism (and thus lower pH) than non-cancerous cells. We have used the pH sensitive ligand, 6,6'-dihydroxy-2,2'-bipyridine (66'bpy(OH)2), to generate [Ru(bpy)2(66'(bpy(OH)2)](2+), which contains two acidic hydroxyl groups with pKa1=5.26 and pKa2=7.27. Irradiation when protonated leads to photo-dissociation of the 66'bpy(OH)2 ligand. An in-depth study of the structural and electronic properties of the complex was carried out using X-ray crystallography, electrochemistry, UV/visible spectroscopy, and computational techniques. Notably, RuN bond lengths in the 66'bpy(OH)2 complex are longer (by ~0.3Å) than in polypyridyl complexes that lack 6 and 6' substitution. Thus, the longer bond length predisposes the complex for photo-dissociation and leads to the anti-cancer activity. When the complex is deprotonated, the 66'bpy(O(-))2 ligand molecular orbitals mix heavily with the ruthenium orbitals, making new mixed metal-ligand orbitals that lead to a higher bond order. We investigated the anti-cancer activities of [Ru(bpy)2(66'(bpy(OH)2)](2+), [Ru(bpy)2(44'(bpy(OH)2)](2+), and [Ru(bpy)3](2+) (44'(bpy(OH)2=4,4'-dihydroxy-2,2'-bipyridine) in HeLa cells, which have a relatively low pH. It is found that [Ru(bpy)2(66'(bpy(OH)2)](2+) is more cytotoxic than the other ruthenium complexes studied. Thus, we have identified a pH sensitive ruthenium scaffold that can be exploited for photo-induced anti-cancer activity.

  2. Short Communication: Investigating a Chain of HIV Transmission Events Due to Homosexual Exposure and Blood Transfusion Based on a Next Generation Sequencing Method.

    PubMed

    Zhao, Qi; Zhang, Chen; Jiang, Yan; Wen, Yujie; Pan, Pinliang; Li, Yang; Zhang, Guiyun; Zhang, Lei; Qiu, Maofeng

    2015-12-01

    This study investigates a chain of HIV transmission events due to homosexual exposure and blood transfusion in China. The MiSeq platform, a next generation sequencing (NGS) system, was used to obtain genetic details of the HIV-1 env region (336 base pairs). Evolutionary analysis combined with epidemiologic evidence suggests a transmission chain from patient T3 to T2 through homosexual exposure and subsequently to T1 through blood transfusion. More importantly, a phylogenetic study suggested a likely genetic bottleneck for HIV in homosexual transmission from T3 to T2, while T1 inherited the majority of variants from T2. The result from the MiSeq platform is consistent with findings from the epidemiologic survey. The MiSeq platform is a powerful tool for tracing HIV transmissions and intrapersonal evolution.

  3. Common skin infection due to Panton-Valentine leucocidin-producing Staphylococcus aureus strains in asylum seekers from Eritrea: a genome-based investigation of a suspected outbreak.

    PubMed

    Jaton, L; Pillonel, T; Jaton, K; Dory, E; Prod'hom, G; Blanc, D S; Tissot, F; Bodenmann, P; Greub, G

    2016-08-01

    Since late 2014, multiple cases of abscesses and boils due to methicillin-susceptible Staphylococcus aureus (MSSA) expressing the Panton-Valentine leucocidin (PVL) were observed in Eritrean asylum seekers in Lausanne, Switzerland. Strains isolated from infected Eritrean and non-Eritrean patients were compared by whole genome sequencing to determine whether these numerous cases result from an outbreak. The genome of S. aureus PVL-producing strains were sequenced and compared. Clinical and epidemiological characteristics of patients infected by PVL-producing strains were investigated. This work reports 15 cases of infections due to PVL-producing strains affecting mostly asylum seekers (n = 10), people working with refugees and/or exposed to Africans (n = 3). Most infections were due to closely related strains of CC152 (n = 8) and CC15 (n = 3), two distantly related (>34 000 core single nucleotide polymorphisms) clonal complexes. An epidemiological link between the 15 cases could be ruled out by whole genome sequencing (33 to 172 core single nucleotide polymorphisms between the different strains of a given complex). Altogether, these results reflect the probable high incidence of CC15 and CC152 PVL-producing strains in eastern Africa. Clinicians facing unusual skin infections in African refugees (or in any person returning from this region of high endemicity) should consider S. aureus PVL-producer before suspecting rare infections such as leishmaniasis or rickettsiosis. Clinicians should also remember that PVL are frequently expressed by MSSA in some regions of the world and that antibiotics that are efficient on toxin expression, such as clindamycin, represent the best therapeutic option.

  4. Use of basophil activation test in the investigation of adverse effects to vaccines.

    PubMed

    Chirumbolo, Salvatore

    2011-08-01

    Diagnosis of adverse effects caused by vaccines mainly includes investigative approaches based on skin tests, histamine, tryptase and serum IgE levels which should allow to diagnose an IgE-mediated allergy reaction, most caused by additive components. Incidence of vaccine-related allergy and anaphylaxis due to vaccination are very poorly represented among population, based on the latest epidemiological and safety reports. Notwithstanding, routinely allergy diagnostic tools show many pitfalls and contradictory results when used to highlight an allergy onset or a clinical manifestation recalling an hypersensitivity reaction. Furthermore, adjuvants in vaccines may trigger innate cells response by toll-like receptors, thus eliciting a possible non-IgE mediated allergy phenomenon or causing B-cell activation and autoimmunity. A cellular test, such as a basophil activation test, or more widely a flow cytometry analysis of immune cells, might add new insights to the comprehension of allergy due to vaccination , thus ameliorating the diagnostic endowment in the hand of physicians.

  5. Yeast growth in raffinose results in resistance to acetic-acid induced programmed cell death mostly due to the activation of the mitochondrial retrograde pathway.

    PubMed

    Guaragnella, Nicoletta; Zdralević, Maša; Lattanzio, Paolo; Marzulli, Domenico; Pracheil, Tammy; Liu, Zhengchang; Passarella, Salvatore; Marra, Ersilia; Giannattasio, Sergio

    2013-12-01

    In order to investigate whether and how a modification of mitochondrial metabolism can affect yeast sensitivity to programmed cell death (PCD) induced by acetic acid (AA-PCD), yeast cells were grown on raffinose, as a sole carbon source, which, differently from glucose, favours mitochondrial respiration. We found that, differently from glucose-grown cells, raffinose-grown cells were mostly resistant to AA-PCD and that this was due to the activation of mitochondrial retrograde (RTG) response, which increased with time, as revealed by the up-regulation of the peroxisomal isoform of citrate synthase and isocitrate dehydrogenase isoform 1, RTG pathway target genes. Accordingly, the deletion of RTG2 and RTG3, a positive regulator and a transcription factor of the RTG pathway, resulted in AA-PCD, as shown by TUNEL assay. Neither deletion in raffinose-grown cells of HAP4, encoding the positive regulatory subunit of the Hap2,3,4,5 complex nor constitutive activation of the RTG pathway in glucose-grown cells due to deletion of MKS1, a negative regulator of RTG pathway, had effect on yeast AA-PCD. The RTG pathway was found to be activated in yeast cells containing mitochondria, in which membrane potential was measured, capable to consume oxygen in a manner stimulated by the uncoupler CCCP and inhibited by the respiratory chain inhibitor antimycin A. AA-PCD resistance in raffinose-grown cells occurs with a decrease in both ROS production and cytochrome c release as compared to glucose-grown cells en route to AA-PCD.

  6. Green synthesis, spectroscopic investigation and photocatalytic activity of lead nanoparticles.

    PubMed

    Elango, Ganesh; Roopan, Selvaraj Mohana

    2015-03-15

    Most of researcher focused their research towards synthesize of nanoparticles by the method of applied chemical method which was one of the costliest method. We have focused cheapest and simplest method for the synthesizing of lead nanoparticles (Pb-NPs) using cocos nucifera L extract. The methanolic extract of cocos nucifera L was efficiently used as a reducing agent for synthesizing Pb-NPs. On treatment of lead acetate with cocos nucifera coir extracts, stable Pb-NPs were formed. The synthesized Pb-NPs were further confirmed by UV-visible spectroscopy, X-ray diffraction (XRD), Transmission electron microscope (TEM) and Energy Dispersive (EDAX) analysis. The secondary metabolites present in methanolic extract which can mainly act as a reducing and capping agents for the formation of Pb-NPs were identified by GC-MS. Anti-microbial activity for Pb-NPs against four pathogenic strain's such as Staphylococcus aureus, Escheria coli, Staphylococcus epidermis and Bacillus subtilis. Result states that Pb-NPs size was 47 nm and also shows good activity against S. aureus. Further we report on photocatalytic absorption of malachite green dye processed in short UV wavelength at 254 nm. UV spectral analysis showed peak absorbance at 613 nm with special reference to the excitation of surfaces plasmon vibration by Pb-NPs.

  7. Green synthesis, spectroscopic investigation and photocatalytic activity of lead nanoparticles

    NASA Astrophysics Data System (ADS)

    Elango, Ganesh; Roopan, Selvaraj Mohana

    2015-03-01

    Most of researcher focused their research towards synthesize of nanoparticles by the method of applied chemical method which was one of the costliest method. We have focused cheapest and simplest method for the synthesizing of lead nanoparticles (Pb-NPs) using cocos nucifera L extract. The methanolic extract of cocos nucifera L was efficiently used as a reducing agent for synthesizing Pb-NPs. On treatment of lead acetate with cocos nucifera coir extracts, stable Pb-NPs were formed. The synthesized Pb-NPs were further confirmed by UV-visible spectroscopy, X-ray diffraction (XRD), Transmission electron microscope (TEM) and Energy Dispersive (EDAX) analysis. The secondary metabolites present in methanolic extract which can mainly act as a reducing and capping agents for the formation of Pb-NPs were identified by GC-MS. Anti-microbial activity for Pb-NPs against four pathogenic strain's such as Staphylococcus aureus, Escheria coli, Staphylococcus epidermis and Bacillus subtilis. Result states that Pb-NPs size was 47 nm and also shows good activity against S. aureus. Further we report on photocatalytic absorption of malachite green dye processed in short UV wavelength at 254 nm. UV spectral analysis showed peak absorbance at 613 nm with special reference to the excitation of surfaces plasmon vibration by Pb-NPs.

  8. Synthesis of marmycin A and investigation into its cellular activity

    NASA Astrophysics Data System (ADS)

    Cañeque, Tatiana; Gomes, Filipe; Mai, Trang Thi; Maestri, Giovanni; Malacria, Max; Rodriguez, Raphaël

    2015-09-01

    Anthracyclines such as doxorubicin are used extensively in the treatment of cancers. Anthraquinone-related angucyclines also exhibit antiproliferative properties and have been proposed to operate via similar mechanisms, including direct genome targeting. Here, we report the chemical synthesis of marmycin A and the study of its cellular activity. The aromatic core was constructed by means of a one-pot multistep reaction comprising a regioselective Diels-Alder cycloaddition, and the complex sugar backbone was introduced through a copper-catalysed Ullmann cross-coupling, followed by a challenging Friedel-Crafts cyclization. Remarkably, fluorescence microscopy revealed that marmycin A does not target the nucleus but instead accumulates in lysosomes, thereby promoting cell death independently of genome targeting. Furthermore, a synthetic dimer of marmycin A and the lysosome-targeting agent artesunate exhibited a synergistic activity against the invasive MDA-MB-231 cancer cell line. These findings shed light on the elusive pathways through which anthraquinone derivatives act in cells, pointing towards unanticipated biological and therapeutic applications.

  9. Virtual Investigations of an Active Deep Sea Volcano

    NASA Astrophysics Data System (ADS)

    Sautter, L.; Taylor, M. M.; Fundis, A.; Kelley, D. S.; Elend, M.

    2013-12-01

    Axial Seamount, located on the Juan de Fuca spreading ridge 300 miles off the Oregon coast, is an active volcano whose summit caldera lies 1500 m beneath the sea surface. Ongoing construction of the Regional Scale Nodes (RSN) cabled observatory by the University of Washington (funded by the NSF Ocean Observatories Initiative) has allowed for exploration of recent lava flows and active hydrothermal vents using HD video mounted on the ROVs, ROPOS and JASON II. College level oceanography/marine geology online laboratory exercises referred to as Online Concept Modules (OCMs) have been created using video and video frame-captured mosaics to promote skill development for characterizing and quantifying deep sea environments. Students proceed at their own pace through a sequence of short movies with which they (a) gain background knowledge, (b) learn skills to identify and classify features or biota within a targeted environment, (c) practice these skills, and (d) use their knowledge and skills to make interpretations regarding the environment. Part (d) serves as the necessary assessment component of the laboratory exercise. Two Axial Seamount-focused OCMs will be presented: 1) Lava Flow Characterization: Identifying a Suitable Cable Route, and 2) Assessing Hydrothermal Vent Communities: Comparisons Among Multiple Sulfide Chimneys.

  10. Investigations of biomechanical activity of macrophages during phagocytosis

    NASA Astrophysics Data System (ADS)

    Kovari, Daniel; Curtis, Jennifer

    2012-02-01

    Phagocytosis has traditionally been investigated in terms of the relevant biochemical signaling pathways that trigger the process and lead to the deformation of the cell as it engulfs a target. Physical changes in the cell include rearrangement and polymerization of actin in the phagocytic cup, large membrane deformations, increased membrane area via exocytosis, and closure of the phagocytic cup through membrane fusion. Hence, phagocytosis is a fine-tuned balance between biophysical cellular events and chemical signaling, which are responsible for driving these materials and mechanical changes. We present a series of assays designed to probe the physical/mechanical parameters that govern a cell during phagocytosis. Custom built micropipette manipulators are used to manipulate individual cells, facilitating high-resolution microscopy of individual phagocytic events. This work has been supported by NSF PoLS #0848797.

  11. Methamphetamine-seeking behavior is due to inhibition of nicotinic cholinergic transmission by activation of cannabinoid CB1 receptors.

    PubMed

    Hiranita, Takato; Nawata, Yoko; Sakimura, Katsuya; Yamamoto, Tsuneyuki

    2008-12-01

    We previously reported the involvement of cannabinoid CB1 receptors (CB1Rs) and nicotinic acetylcholine receptors (nAChRs) in the reinstatement of methamphetamine (MAP)-seeking behavior (lever-pressing response for MAP reinforcement under saline infusion). The present study examined whether the reinstatement involves interactions between these receptors. Rats were trained to self-administer MAP with a light and tone (MAP-associated cues). Then, extinction sessions under saline infusion without cues were conducted. After that, a reinstatement tests were conducted by either presenting the cues or a MAP-priming injection. Systemic and intracranial administration of HU210, a cannabinoid CB1R agonist, into the nucleus accumbens core (NAC) and prelimbic cortex (PrC) reinstated MAP-seeking behavior. The reinstatement caused by the systemic HU210 treatment was attenuated by intracranial administration of AM251, a cannabinoid CB1R antagonist, into each region mentioned above. Meanwhile, reinstatement induced by the MAP-associated cues and MAP-priming injection was also attenuated by intracranial administration of AM251 in each region. In these regions, the attenuating effects of AM251 on the reinstatement induced by each stimulus were blocked by the intracranial administration of mecamylamine, a non-selective nAChR antagonist, but not by scopolamine, a muscarinic ACh receptor (mAChR) antagonist. Furthermore, the intracranial administration of DHbetaE, an alpha4beta2 nAChR antagonist, but not MLA, an alpha7 nAChR antagonist, into each region blocked the AM251-induced attenuation of the reinstatement. These findings suggest that relapses to MAP-seeking behavior may be due to two steps, first inhibition of ACh transmission by the activation of cannabinoid CB1Rs and then the inactivation of alpha4beta2 nAChRs.

  12. The Miscoding Potential of 5-Hydroxycytosine Arises Due to Template Instability in the Replicative Polymerase Active Site

    SciTech Connect

    Zahn, Karl E.; Averill, April; Wallace, Susan S.; Doublié, Sylvie

    2012-07-18

    5-Hydroxycytosine (5-OHC) is a stable oxidation product of cytosine associated with an increased frequency of C {yields} T transition mutations. When this lesion escapes recognition by the base excision repair pathway and persists to serve as a templating base during DNA synthesis, replicative DNA polymerases often misincorporate dAMP at the primer terminus, which can lead to fixation of mutations and subsequent disease. To characterize the dynamics of DNA synthesis opposite 5-OHC, we initiated a comparison of unmodified dCMP to 5-OHC, 5-fluorocytosine (5-FC), and 5-methylcytosine (5-MEC) in which these bases act as templates in the active site of RB69 gp43, a high-fidelity DNA polymerase sharing homology with human replicative DNA polymerases. This study presents the first crystal structure of any DNA polymerase binding this physiologically important premutagenic DNA lesion, showing that while dGMP is stabilized by 5-OHC through normal Watson-Crick base pairing, incorporation of dAMP leads to unstacking and instability in the template. Furthermore, the electronegativity of the C5 substituent appears to be important in the miscoding potential of these cytosine-like templates. While dAMP is incorporated opposite 5-OHC {approx}5 times more efficiently than opposite unmodified dCMP, an elevated level of incorporation is also observed opposite 5-FC but not 5-MEC. Taken together, these data imply that the nonuniform templating by 5-OHC is due to weakened stacking capabilities, which allows dAMP incorporation to proceed in a manner similar to that observed opposite abasic sites.

  13. Mechanistic investigation of industrial wastewater naphthenic acids removal using granular activated carbon (GAC) biofilm based processes.

    PubMed

    Islam, Md Shahinoor; Zhang, Yanyan; McPhedran, Kerry N; Liu, Yang; Gamal El-Din, Mohamed

    2016-01-15

    Naphthenic acids (NAs) found in oil sands process-affected waters (OSPW) have known environmental toxicity and are resistant to conventional wastewater treatments. The granular activated carbon (GAC) biofilm treatment process has been shown to effectively treat OSPW NAs via combined adsorption/biodegradation processes despite the lack of research investigating their individual contributions. Presently, the NAs removals due to the individual processes of adsorption and biodegradation in OSPW bioreactors were determined using sodium azide to inhibit biodegradation. For raw OSPW, after 28 days biodegradation and adsorption contributed 14% and 63% of NA removal, respectively. For ozonated OSPW, biodegradation removed 18% of NAs while adsorption reduced NAs by 73%. Microbial community 454-pyrosequencing of bioreactor matrices indicated the importance of biodegradation given the diverse carbon degrading families including Acidobacteriaceae, Ectothiorhodospiraceae, and Comamonadaceae. Overall, results highlight the ability to determine specific processes of NAs removals in the combined treatment process in the presence of diverse bacteria metabolic groups found in GAC bioreactors.

  14. Approach for Estimating Exposures and Incremental Health Effects from Lead Due to Renovation Repair and Painting Activities in Public and Commercial Buildings

    EPA Pesticide Factsheets

    Approach for Estimating Exposures and Incremental Health Effects from Lead Due to Renovation Repair and Painting Activities in Public and Commercial Buildings: links to documents at www.regulations.gov, links to PDFs related to Approach document

  15. Effects on shortening velocity of rabbit skeletal muscle due to variations in the level of thin-filament activation.

    PubMed Central

    Moss, R L

    1986-01-01

    The effect of Ca2+ upon maximum shortening velocity (Vmax) has been investigated in skinned single fibres from rabbit psoas muscles. Vmax was obtained at 15 degrees C by measuring the amounts of time (delta t) required to take up various amounts of slack (delta l) imposed at one end of the fibre. During maximal activation with Ca2+, plots of delta l vs. delta t were well fitted by a single straight line. Calculation of Vmax from the slopes of the fitted lines yielded a Vmax of 4.44 +/- 0.15 (S.E. of mean) muscle lengths per second (m.l./s). However, at lower levels of Ca2+ activation, plots of delta l vs. delta t were biphasic, containing an initial phase of steady high-velocity shortening and a subsequent phase of steady low-velocity shortening. The transition between these two phases occurred following active shortening equivalent to 60-80 nm/half-sarcomere. Vmax during the high-velocity phase was relatively insensitive to Ca2+ concentration between pCas (i.e. -log [Ca2+]) of 4.5 and 6.0; however, Vmax fell to 3.58 +/- 0.40 m.l./s at pCa 6.1 and further to 1.02 +/- 0.30 m.l./s at pCa 6.2. Vmax during the low-velocity phase decreased as Ca2+ was lowered within the entire range of pCas studied to a minimum value of 0.35 +/- 0.09 m.l./s at pCa 6.2. The degree of thin-filament activation at a particular pCa was varied by partial extraction of troponin-C, which resulted in a permanent though reversible inactivation of parts of the thin filaments. Partial extraction of troponin-C altered the plots of delta l vs. delta t obtained at pCa 4.5 to a biphasic form. In addition, Vmax during the high- and low-velocity phases of shortening was reduced at each pCa greater than 4.5. Vmax values obtained in control fibres at low Ca2+ concentrations and extracted fibres were in good agreement when generated isometric tensions were equivalent. This was the case for both the high- and low-velocity phases of shortening. Fibres were also activated in the absence of Ca2+ by partial

  16. Investigating the antiplasmodial activity of primary sulfonamide compounds identified in open source malaria data.

    PubMed

    Fisher, Gillian M; Bua, Silvia; Del Prete, Sonia; Arnold, Megan S J; Capasso, Clemente; Supuran, Claudiu T; Andrews, Katherine T; Poulsen, Sally-Ann

    2017-04-01

    In the past decade there has been a significant reduction in deaths due to malaria, in part due to the success of the gold standard antimalarial treatment - artemisinin combination therapies (ACTs). However the potential threat of ACT failure and the lack of a broadly effective malaria vaccine are driving efforts to discover new chemical entities (NCEs) to target this disease. The primary sulfonamide (PS) moiety is a component of several clinical drugs, including those for treatment of kidney disease, glaucoma and epilepsy, however this chemotype has not yet been exploited for malaria. In this study 31 PS compounds sourced from the GlaxoSmithKline (GSK) Tres Cantos antimalarial set (TCAMS) were investigated for their ability to selectively inhibit the in vitro growth of Plasmodium falciparum asexual stage malaria parasites. Of these, 14 compounds were found to have submicromolar activity (IC50 0.16-0.89 μM) and a modest selectivity index (SI) for the parasite versus human cells (SI > 12 to >43). As the PS moiety is known to inhibit carbonic anhydrase (CA) enzymes from many organisms, the PS compounds were assessed for recombinant P. falciparum CA (PfCA) mediated inhibition of CO2 hydration. The PfCA inhibition activity did not correlate with antiplasmodial potency. Furthermore, no significant difference in IC50 was observed for P. falciparum versus P. knowlesi (P > 0.05), a Plasmodium species that is not known to contain an annotated PfCA gene. Together these data suggest that the asexual intraerythrocytic stage antiplasmodial activity of the PS compounds examined in this study is likely unrelated to PfCA inhibition.

  17. Monte Carlo simulations of patient dose perturbations in rotational-type radiotherapy due to a transverse magnetic field: A tomotherapy investigation

    SciTech Connect

    Yang, Y. M.; Geurts, M.; Smilowitz, J. B.; Bednarz, B. P.; Sterpin, E.

    2015-02-15

    Purpose: Several groups are exploring the integration of magnetic resonance (MR) image guidance with radiotherapy to reduce tumor position uncertainty during photon radiotherapy. The therapeutic gain from reducing tumor position uncertainty using intrafraction MR imaging during radiotherapy could be partially offset if the negative effects of magnetic field-induced dose perturbations are not appreciated or accounted for. The authors hypothesize that a more rotationally symmetric modality such as helical tomotherapy will permit a systematic mediation of these dose perturbations. This investigation offers a unique look at the dose perturbations due to homogeneous transverse magnetic field during the delivery of Tomotherapy{sup ®} Treatment System plans under varying degrees of rotational beamlet symmetry. Methods: The authors accurately reproduced treatment plan beamlet and patient configurations using the Monte Carlo code GEANT4. This code has a thoroughly benchmarked electromagnetic particle transport physics package well-suited for the radiotherapy energy regime. The three approved clinical treatment plans for this study were for a prostate, head and neck, and lung treatment. The dose heterogeneity index metric was used to quantify the effect of the dose perturbations to the target volumes. Results: The authors demonstrate the ability to reproduce the clinical dose–volume histograms (DVH) to within 4% dose agreement at each DVH point for the target volumes and most planning structures, and therefore, are able to confidently examine the effects of transverse magnetic fields on the plans. The authors investigated field strengths of 0.35, 0.7, 1, 1.5, and 3 T. Changes to the dose heterogeneity index of 0.1% were seen in the prostate and head and neck case, reflecting negligible dose perturbations to the target volumes, a change from 5.5% to 20.1% was observed with the lung case. Conclusions: This study demonstrated that the effect of external magnetic fields can

  18. Classification of prefrontal activity due to mental arithmetic and music imagery using hidden Markov models and frequency domain near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Power, Sarah D.; Falk, Tiago H.; Chau, Tom

    2010-04-01

    Near-infrared spectroscopy (NIRS) has recently been investigated as a non-invasive brain-computer interface (BCI). In particular, previous research has shown that NIRS signals recorded from the motor cortex during left- and right-hand imagery can be distinguished, providing a basis for a two-choice NIRS-BCI. In this study, we investigated the feasibility of an alternative two-choice NIRS-BCI paradigm based on the classification of prefrontal activity due to two cognitive tasks, specifically mental arithmetic and music imagery. Deploying a dual-wavelength frequency domain near-infrared spectrometer, we interrogated nine sites around the frontopolar locations (International 10-20 System) while ten able-bodied adults performed mental arithmetic and music imagery within a synchronous shape-matching paradigm. With the 18 filtered AC signals, we created task- and subject-specific maximum likelihood classifiers using hidden Markov models. Mental arithmetic and music imagery were classified with an average accuracy of 77.2% ± 7.0 across participants, with all participants significantly exceeding chance accuracies. The results suggest the potential of a two-choice NIRS-BCI based on cognitive rather than motor tasks.

  19. An investigation of gap heating due to stepped tiles in zero pressure gradient regions of the Shuttle Orbiter Thermal Protection System

    NASA Technical Reports Server (NTRS)

    Smith, D. M.; Petley, D. H.; Edwards, C. L. W.; Patten, A. B.

    1983-01-01

    An analytical study is presented which investigates the cause of the excessive heating in the tile-to-tile gaps of the Shuttle Orbiter Thermal Protection System, as evidenced by the visible discoloration and charring of the filler bar and strain isolation pad used in the attachment of tiles to the aluminum substrate. Techniques are developed to estimate the pressure disturbances due to a stepped tile and to calculate the disturbance-induced mass flow rates in the tile-to-tile gaps, filler bar, strain isolation pad, and the tile itself. A thermal analysis in the tile-to-tile gap is then performed in order to determine the temperature response to the hot gas flow. Calculations are performed at locations on the fuselage and the left wing where damaged filler bars were observed on the first flight of the Shuttle. It is concluded that the steps and gaps must be controlled within tight tolerances during tile installation and the tolerances must be maintained in flight. If the tolerances cannot be maintained, tile-to-tile gap filler may be an alternative.

  20. Numerical investigation on the stabilization of the deceleration phase Rayleigh-Taylor instability due to alpha particle heating in ignition target

    NASA Astrophysics Data System (ADS)

    Fan, Zhengfeng; Zhu, Shaoping; Pei, Wenbing; Ye, Wenhua; Li, Meng; Xu, Xiaowen; Wu, Junfeng; Dai, Zhensheng; Wang, Lifeng

    2012-09-01

    Tritium-hydrogen-deuterium (THD) target is adopted in order to experimentally diagnose the properties of the ignition hot spot and the highly compressed main fusion fuel (Edwards M. J. et al., Phys. Plasmas, 18 (2011) 051003). As compared with deuterium-tritium (DT) target, the thermonuclear alpha particles which are needed to heat the fusion fuel, are much less in the THD target. In the present paper, the effect of alpha particle heating on the deceleration phase Rayleigh-Taylor instability (dp-RTI), which is one of the key problems in hot spot formation, is investigated systematically through numerical simulations. It is found that the mass ablation at the hot spot boundary is greatly increased due to the direct alpha particle heating. As a result, the dp-RTI growth rates are greatly reduced and the cut-off mode number decreases greatly from about 33 to 17. This explains why the hydrodynamic instability in the THD target grows more severely than in the DT ignition target.

  1. Investigation of levels in ambient air near sources of Polychlorinated Biphenyls (PCBs) in Kanpur, India, and risk assessment due to inhalation.

    PubMed

    Goel, Anubha; Upadhyay, Kritika; Chakraborty, Mrinmoy

    2016-05-01

    Polychlorinated biphenyls (PCBs) are a class of organic compounds listed as persistent organic pollutant and have been banned for use under Stockholm Convention (1972). They were used primarily in transformers and capacitors, paint, flame retardants, plasticizers, and lubricants. PCBs can be emitted through the primary and secondary sources into the atmosphere, undergo long-range atmospheric transport, and hence have been detected worldwide. Reported levels in ambient air are generally higher in urban areas. Active sampling of ambient air was conducted in Kanpur, a densely populated and industrialized city in the Indo-Gangetic Plain, for detection of 32 priority PCBs, with the aim to determine the concentration in gas/particle phase and assess exposure risk. More than 50 % of PCBs were detected in air. Occurrence in particles was dominated by heavier congeners, and levels in gas phase were below detection. Levels determined in this study are lower than the levels in Coastal areas of India but are at par with other Asian countries where majority of sites chosen for sampling were urban industrial areas. Human health risk estimates through air inhalation pathway were made in terms of lifetime average daily dose (LADD) and incremental lifetime cancer risks (ILCR). The study found lower concentrations of PCBs than guideline values and low health risk estimates through inhalation within acceptable levels, indicating a minimum risk to the adults due to exposure to PCBs present in ambient air in Kanpur.

  2. An Investigation of Wing and Aileron Loads Due to Deflected Inboard and Outboard Ailerons on a 4-Percent-Thick 30 deg Sweptback Wing at Transonic Speeds

    NASA Technical Reports Server (NTRS)

    Whitcomb, Charles F.; Critzos, Chris C.; Brown, Philippa F.

    1961-01-01

    An investigation has been conducted in the Langley 16-foot transonic tunnel to determine the changes in wing loading characteristics due to deflections of a plain faired flap-type inboard aileron, a plain faired flap-type outboard aileron, and a slab-sided thickened trailing edge outboard aileron. The test wing was 4 percent thick and had 30 sweep of the quarter chord, an aspect ratio of 3.0, a taper ratio of 0.2, and NACA 65A004 airfoil sections. The loading characteristics of the deflected ailerons were also investigated. The model was a sting-mounted wing-body combination, and pressure measurements over one wing panel (exposed area) and the ailerons were obtained for angles of attack from 0 to 20 at deflections up to +/- 15 deg for Mach numbers between 0.80 and 1.03. The test Reynolds number based on the wing mean aerodynamic chord was about 7.4 x 10(exp 6). The results of the investigation indicated that positive deflection of the plain faired flap-type inboard aileron caused significant added loading over the wing sections outboard of the aileron at all Mach numbers for model angles of attack from 0 deg or 4 deg up to 12 deg. Positive deflection of the two outboard ailerons (plain faired and slab sided with thickened trailing edge) caused significant added loading over the wing sections inboard of the ailerons for different model angle-of-attack ranges at the several test Mach numbers. The loading shapes over the ailerons were irregular and would be difficult to predict from theoretical considerations in the transonic speed range. The longitudinal and lateral center-of-pressure locations for the ailerons varied only slightly with increasing angle of attack and/or Mach number. Generally, the negative slopes of the variations of aileron hinge-moment coefficient with aileron deflection for all three ailerons varied similarly with Mach number at the test angles of attack.

  3. Investigation on the two-stage active magnetic regenerative refrigerator for liquefaction of hydrogen

    SciTech Connect

    Park, Inmyong; Park, Jiho; Jeong, Sangkwon; Kim, Youngkwon

    2014-01-29

    An active magnetic regenerative refrigerator (AMRR) is expected to be useful for hydrogen liquefaction due to its inherent high thermodynamic efficiency. Because the temperature of the cold end of the refrigerator has to be approximately liquid temperature, a large temperature span of the active magnetic regenerator (AMR) is indispensable when the heat sink temperature is liquid nitrogen temperature or higher. Since magnetic refrigerants are only effective in the vicinity of their own transition temperatures, which limit the temperature span of the AMR, an innovative structure is needed to increase the temperature span. The AMR must be a layered structure and the thermophysical matching of magnetic field and flow convection effects is very important. In order to design an AMR for liquefaction of hydrogen, the implementation of multi-layered AMR with different magnetic refrigerants is explored with multi-staging. In this paper, the performance of the multi-layered AMR using four rare-earth compounds (GdNi{sub 2}, Gd{sub 0.1}Dy{sub 0.9}Ni{sub 2}, Dy{sub 0.85}Er{sub 0.15}Al{sub 2}, Dy{sub 0.5}Er{sub 0.5}Al{sub 2}) is investigated. The experimental apparatus includes two-stage active magnetic regenerator containing two different magnetic refrigerants each. A liquid nitrogen reservoir connected to the warm end of the AMR maintains the temperature of the warm end around 77 K. High-pressure helium gas is employed as a heat transfer fluid in the AMR and the maximum magnetic field of 4 T is supplied by the low temperature superconducting (LTS) magnet. The temperature span with the variation of parameters such as phase difference between magnetic field and mass flow rate of magnetic refrigerants in AMR is investigated. The maximum temperature span in the experiment is recorded as 50 K and several performance issues have been discussed in this paper.

  4. Neural substrates associated with evaluative processing during co-activation of positivity and negativity: a PET investigation.

    PubMed

    Jung, Young Chul; An, Suk Kyoon; Seok, Jeong Ho; Kim, Jae Seung; Oh, Seung Jun; Moon, Dae Hyuk; Kim, Jae-Jin

    2006-10-01

    Affective symmetries, such as the positivity offset and negativity bias, have been postulated to be attributable to distinct activation functions of the positive and negative affect systems. We investigated the neural substrates that are engaged when the positive and negative affect systems undergo parallel and integrative processing. Eleven subjects were scanned using H(2)(15)O PET during choosing the subjective feeling produced by a stimulation pair of pictures or words. Four different conditions were designed for contrast: pure positivity, pure negativity, positivity offset, and negativity bias. The dorsolateral prefrontal activation was associated with positivity offset and negativity bias condition, whereas the ventromedial prefrontal activation, together with limbic and subcortical activations, was associated with pure positivity and pure negativity condition. The results indicated that positivity offset and negativity bias are not merely due to asymmetric activations of the positive and negative systems, but integrative processing of higher neocortical levels is involved.

  5. Accelerated Ca2+ entry by membrane hyperpolarization due to Ca2+-activated K+ channel activation in response to histamine in chondrocytes.

    PubMed

    Funabashi, Kenji; Ohya, Susumu; Yamamura, Hisao; Hatano, Noriyuki; Muraki, Katsuhiko; Giles, Wayne; Imaizumi, Yuji

    2010-04-01

    In articular cartilage inflammation, histamine release from mast cells is a key event. It can enhance cytokine production and matrix synthesis and also promote cell proliferation by stimulating chondrocytes. In this study, the functional impact of Ca(2+)-activated K(+) (K(Ca)) channels in the regulation of intracellular Ca(2+) concentration ([Ca(2+)](i)) in chondrocytes in response to histamine was examined using OUMS-27 cells, as a model of chondrocytes derived from human chondrosarcoma. Application of histamine induced a significant [Ca(2+)](i) rise and also membrane hyperpolarization, and both effects were mediated by the stimulation of H(1) receptors. The histamine-induced membrane hyperpolarization was attenuated to approximately 50% by large-conductance K(Ca) (BK) channel blockers, and further reduced by intermediate (IK) and small conductance K(Ca) (SK) channel blockers. The tonic component of histamine-induced [Ca(2+)](i) rise strongly depended on the presence of extracellular Ca(2+) ([Ca(2+)](o)) and was markedly reduced by La(3+) or Gd(3+) but not by nifedipine. It was significantly attenuated by BK channel blockers, and further blocked by the cocktail of BK, IK, and SK channel blockers. The K(Ca) blocker cocktail also significantly reduced the store-operated Ca(2+) entry (SOCE), which was induced by Ca(2+) addition after store-depletion by thapsigargin in [Ca(2+)](o) free solution. Our results demonstrate that the histamine-induced membrane hyperpolarization in chondrocytes due to K(Ca) channel activation contributes to sustained Ca(2+) entry mainly through SOCE channels in OUMS-27 cells. Thus, K(Ca) channels appear to play an important role in the positive feedback mechanism of [Ca(2+)](i) regulation in chondrocytes in the presence of articular cartilage inflammation.

  6. An investigation of reactivity effect due to inadvertent filling of the irradiation channels with water in NIRR-1 Nigeria Research Reactor-1.

    PubMed

    Iliyasu, U; Ibrahim, Y V; Umar, Sadiq; Agbo, S A; Jibrin, Y

    2017-02-09

    Investigation of reactivity variation due to flooding of the irradiation channels of Nigeria Research Reactor (NIRR-1) a low power miniature neutron source reactor (MNSR) located at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria Nigeria using the MCNP code for High Enrich Uranium (HEU) and Low Enrich Uranium (LEU) core has been simulated in this present study. In this work, the excess reactivity worth of flooding HEU core for 1 inner, 2 inner, 3 inner, 4 inner and all inner are 0.318mk, 0.577mk, 0.318mk, 1.204mk and 1.503mk respectively, and outer irradiation channels are 0.119mk, 0.169mk, 0.348mk, 0.438mk and 0.418mk respectively, the highest excess reactivity result from flooding both inner and outer irradiation channels is 2.04mk (±1.72×10(-7)), the excess reactivity for LEU core was 0.299mk, 0.568mk, 0.896mk, 1.195mk and 1.524mk in the inner irradiation channels, and the outer irradiation channels are 0.129mk, 0.189mk, 0.219mk, 0.269mk and 0.548mk where the highest excess reactivity was 1.942mk (±1.64×10(-7)) resulting from flooding inner and outer irradiation channels. The reactivity induced by flooding of the irradiation channels of NIRR-1 with water is within design safety limit enshrined in Safety Analysis Report of NIRR-1. The results also compare well with literature.

  7. Investigation of the Highly Active Manganese Superoxide Dismutase from Saccharomyces cerevisiae

    SciTech Connect

    Cabelli, D.E.; Barnese, K.; Sheng, Y.; Stich, T.A.; Gralla, E.B.; Britt, R.D.; Valentine, J.S.

    2010-09-15

    Manganese superoxide dismutase (MnSOD) from different species differs in its efficiency in removing high concentrations of superoxide (O{sub 2}{sup -}), due to different levels of product inhibition. Human MnSOD exhibits a substantially higher level of product inhibition than the MnSODs from bacteria. In order to investigate the mechanism of product inhibition and whether it is a feature common to eukaryotic MnSODs, we purified MnSOD from Saccharomyces cerevisiae (ScMnSOD). It was a tetramer with 0.6 equiv of Mn per monomer. The catalytic activity of ScMnSOD was investigated by pulse radiolysis and compared with human and two bacterial (Escherichia coli and Deinococcus radiodurans) MnSODs. To our surprise, ScMnSOD most efficiently facilitates removal of high concentrations of O{sub 2}{sup -} among these MnSODs. The gating value k{sub 2}/k{sub 3} that characterizes the level of product inhibition scales as ScMnSOD > D. radiodurans MnSOD > E. coli MnSOD > human MnSOD. While most MnSODs rest as the oxidized form, ScMnSOD was isolated in the Mn{sup 2+} oxidation state as revealed by its optical and electron paramagnetic resonance spectra. This finding poses the possibility of elucidating the origin of product inhibition by comparing human MnSOD with ScMnSOD.

  8. Electron beam/γ-ray irradiation synthesis of gold nanoparticles and investigation of antioxidant activity

    NASA Astrophysics Data System (ADS)

    Duy Nguyen, Ngoc; Phu Dang, Van; Le, Anh Quoc; Hien Nguyen, Quoc

    2014-12-01

    Colloidal solutions of 1 mM gold nanoparticles (AuNPs) were synthesized by γ-ray Co-60 and electron beam irradiation using 1% water soluble chitosan (WSC) with different molecular weight (Mw) as stabilizer. The AuNPs size measured from TEM images was of 7.1 and 15.1 nm for electron beam and γ-ray Co-60, respectively. The AuNPs sizes of 9.8, 15.1 and 22.4 nm stabilized by different WSC Mw of 155 × 103, 78 × 103 and 29 × 103 g mol-1, respectively, were also synthesized by γ-ray Co-60 irradiation. Antioxidant activity of AuNPs with different size from 7.1 to 20.0 nm was investigated using free radical 2,2‧-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS•+). Results indicated that the smaller size of AuNPs exhibited higher antioxidant activity. In particular, the antioxidant efficiency was of nearly 100, 75, 65, 52 and 30% for 7.1, 9.8, 15.1, 20.0 nm AuNPs and WSC 0.1%, respectively, at the same reaction time of 270 min. Thus, due to the compatibility of WSC and the unique property of AuNPs, the pure colloidal AuNPs/WSC solutions synthesized by irradiation method can be potentially applied in biomedicine, cosmetics and in other fields as well.

  9. Validity of instruments to measure physical activity may be questionable due to a lack of conceptual frameworks: a systematic review

    PubMed Central

    2011-01-01

    Background Guidance documents for the development and validation of patient-reported outcomes (PROs) advise the use of conceptual frameworks, which outline the structure of the concept that a PRO aims to measure. It is unknown whether currently available PROs are based on conceptual frameworks. This study, which was limited to a specific case, had the following aims: (i) to identify conceptual frameworks of physical activity in chronic respiratory patients or similar populations (chronic heart disease patients or the elderly) and (ii) to assess whether the development and validation of PROs to measure physical activity in these populations were based on a conceptual framework of physical activity. Methods Two systematic reviews were conducted through searches of the Medline, Embase, PsycINFO, and Cinahl databases prior to January 2010. Results In the first review, only 2 out of 581 references pertaining to physical activity in the defined populations provided a conceptual framework of physical activity in COPD patients. In the second review, out of 103 studies developing PROs to measure physical activity or related constructs, none were based on a conceptual framework of physical activity. Conclusions These findings raise concerns about how the large body of evidence from studies that use physical activity PRO instruments should be evaluated by health care providers, guideline developers, and regulatory agencies. PMID:21967887

  10. The total protein content, protein fractions and proteases activities of drone prepupae of Apis mellifera due to varrosis.

    PubMed

    Zółtowska, Krystyna; Lipiński, Zbigniew; Dmitryjuk, Małgorzata

    2005-01-01

    The proteins level and activities of acid and alkaline proteases in whole body extracts of drone prepupae of Apis mellifera naturally infested with Varroa destructor were studied. The infested and a non-infested group did not differ significantly in their total protein content. However, some differences in protein profiles were found. A lack of three protein fractions of moderate and lower molecular weight in infested prepupae was noted. Moreover, some differences in the quantity of protein in most of the fractions were observed. The activity of acid proteases from infested prepupae was lower (p < 0.05) compared with the activity of these proteases from the non-infested one group. The infested drone had higher activity of alkaline proteases than non-infested but this difference was not statisticaly significant.

  11. A constitutive active MAPK/ERK pathway due to BRAFV600E positively regulates AHR pathway in PTC

    PubMed Central

    Regazzo, Daniela; Bertazza, Loris; Galuppini, Francesca; Guzzardo, Vincenza; Jaffrain-Rea, Marie Lise; Vianello, Federica; Ciato, Denis; Ceccato, Filippo; Watutantrige-Fernando, Sara; Bisognin, Andrea; Bortoluzzi, Stefania; Pennelli, Gianmaria; Boscaro, Marco; Scaroni, Carla; Mian, Caterina

    2015-01-01

    The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor mediating the toxicity and tumor-promoting properties of dioxin. AHR has been reported to be overexpressed and constitutively active in a variety of solid tumors, but few data are currently available concerning its role in thyroid cancer. In this study we quantitatively explored a series of 51 paired-normal and papillary thyroid carcinoma (PTC) tissues for AHR-related genes. We identified an increased AHR expression/activity in PTC, independently from its nuclear dimerization partner and repressor but strictly related to a constitutive active MAPK/ERK pathway. The AHR up-regulation followed by an increased expression of AHR target genes was confirmed by a meta-analysis of published microarray data, suggesting a ligand-independent active AHR pathway in PTC. In-vitro studies using a PTC-derived cell line (BCPAP) and HEK293 cells showed that BRAFV600E may directly modulate AHR localization, induce AHR expression and activity in an exogenous ligand-independent manner. The AHR pathway might represent a potential novel therapeutic target for PTC in the clinical practice. PMID:26392334

  12. A constitutive active MAPK/ERK pathway due to BRAFV600E positively regulates AHR pathway in PTC.

    PubMed

    Occhi, Gianluca; Barollo, Susi; Regazzo, Daniela; Bertazza, Loris; Galuppini, Francesca; Guzzardo, Vincenza; Jaffrain-Rea, Marie Lise; Vianello, Federica; Ciato, Denis; Ceccato, Filippo; Watutantrige-Fernando, Sara; Bisognin, Andrea; Bortoluzzi, Stefania; Pennelli, Gianmaria; Boscaro, Marco; Scaroni, Carla; Mian, Caterina

    2015-10-13

    The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor mediating the toxicity and tumor-promoting properties of dioxin. AHR has been reported to be overexpressed and constitutively active in a variety of solid tumors, but few data are currently available concerning its role in thyroid cancer. In this study we quantitatively explored a series of 51 paired-normal and papillary thyroid carcinoma (PTC) tissues for AHR-related genes. We identified an increased AHR expression/activity in PTC, independently from its nuclear dimerization partner and repressor but strictly related to a constitutive active MAPK/ERK pathway. The AHR up-regulation followed by an increased expression of AHR target genes was confirmed by a meta-analysis of published microarray data, suggesting a ligand-independent active AHR pathway in PTC. In-vitro studies using a PTC-derived cell line (BCPAP) and HEK293 cells showed that BRAFV600E may directly modulate AHR localization, induce AHR expression and activity in an exogenous ligand-independent manner. The AHR pathway might represent a potential novel therapeutic target for PTC in the clinical practice.

  13. An Investigation into Techniques for the Determination of Moisture Content on Activated Carbon

    DTIC Science & Technology

    1991-09-01

    Activated carbon (or charcoal ) is a universal adsorbent for the removal of a variety of organic/inorganic contaminants, in both gaseous and aqueous phase...AD-A245 938 i * *~fl Nadoni Waren AN INVESTIGATION INTO TECHNIQUES FOR THE DETERMNATION OF MOISTURE CONTENT ON ACTIVATED CARBON (U) by L.E. Cameron...INVESTIGATION INTO TECHNIQUES FOR THE DETERMINATION OF MOISTURE CONTENT ON ACTIVATED CARBON (U) by L.E. Cameron and S.H.C. Liang Chemical Protecti

  14. Computational investigation on the application of using microjets as active aerodynamic load control for wind turbines

    NASA Astrophysics Data System (ADS)

    Blaylock, Myra Louise

    A fast, efficient way to control loads on industrial scale turbines is important for the growth of the wind industry. Active Aerodynamic Load Control (AALC) is one area which addresses this need. In particular, microjets, which are pneumatic jets located at the trailing edge of a wind turbine blade and blow perpendicular to the blade surface, are a possible AALC candidate. First, the Computational Fluid Dynamics (CFD) solver OVERFLOW is used to explore the effects of a microjet on lift, drag, and pitching moment. Then the interaction between an aerodynamic disturbance and an airfoil equipped with a microjet is modeled. The object of this dissertation is to investigate microtabs as viable AALC devices by presenting their aerodynamic properties and testing whether a proportional-integral (PI) controlled jets can alleviate loads caused by wind gusts. The use of CFD to simulate a microjet is validated by comparing the results to both previous experiments found in the literature as well as wind tunnel tests completed at UC Davis. The aerodynamic effectiveness of the jet is investigated as a function of various parameters such as Reynolds number, angle of attack, and the momentum coefficient of the jet. The effects of the microjet are found to be very similar to another AALC device, the microtab. An aerodynamic disturbance is simulated, and a control algorithm which is incorporated into the OVERFLOW code is used to activate the microjet, thus reducing the change of the blade load due to the gust. Finally, a more realistic model is made by adding both a linear and a torsional spring and damper to represent the blade movement. This two-degree of freedom system shows that during a gust the vertical blade movement is reduced when the microjets are activated. Microjets are found to work well to alleviate the changes in aerodynamic loads felt by the airfoil, and are therefore a good candidate for a practical AALC device. However, further investigation is needed in the areas of

  15. Fast skeletal muscle troponin activation increases force of mouse fast skeletal muscle and ameliorates weakness due to nebulin-deficiency.

    PubMed

    Lee, Eun-Jeong; De Winter, Josine M; Buck, Danielle; Jasper, Jeffrey R; Malik, Fady I; Labeit, Siegfried; Ottenheijm, Coen A; Granzier, Henk

    2013-01-01

    The effect of the fast skeletal muscle troponin activator, CK-2066260, on calcium-induced force development was studied in skinned fast skeletal muscle fibers from wildtype (WT) and nebulin deficient (NEB KO) mice. Nebulin is a sarcomeric protein that when absent (NEB KO mouse) or present at low levels (nemaline myopathy (NM) patients with NEB mutations) causes muscle weakness. We studied the effect of fast skeletal troponin activation on WT muscle and tested whether it might be a therapeutic mechanism to increase muscle strength in nebulin deficient muscle. We measured tension-pCa relations with and without added CK-2066260. Maximal active tension in NEB KO tibialis cranialis fibers in the absence of CK-2066260 was ∼60% less than in WT fibers, consistent with earlier work. CK-2066260 shifted the tension-calcium relationship leftwards, with the largest relative increase (up to 8-fold) at low to intermediate calcium levels. This was a general effect that was present in both WT and NEB KO fiber bundles. At pCa levels above ∼6.0 (i.e., calcium concentrations <1 µM), CK-2066260 increased tension of NEB KO fibers to beyond that of WT fibers. Crossbridge cycling kinetics were studied by measuring k(tr) (rate constant of force redevelopment following a rapid shortening/restretch). CK-2066260 greatly increased k(tr) at submaximal activation levels in both WT and NEB KO fiber bundles. We also studied the sarcomere length (SL) dependence of the CK-2066260 effect (SL 2.1 µm and 2.6 µm) and found that in the NEB KO fibers, CK-2066260 had a larger effect on calcium sensitivity at the long SL. We conclude that fast skeletal muscle troponin activation increases force at submaximal activation in both wildtype and NEB KO fiber bundles and, importantly, that this troponin activation is a potential therapeutic mechanism for increasing force in NM and other skeletal muscle diseases with loss of muscle strength.

  16. Quantitative investigation of the mechanisms of microplastics and nanoplastics toward zebrafish larvae locomotor activity.

    PubMed

    Chen, Qiqing; Gundlach, Michael; Yang, Shouye; Jiang, Jing; Velki, Mirna; Yin, Daqiang; Hollert, Henner

    2017-04-15

    This study investigated the direct and indirect toxic effects of microplastics and nanoplastics toward zebrafish (Danio rerio) larvae locomotor activity. Results showed that microplastics alone exhibited no significant effects except for the upregulated zfrho visual gene expression; whereas nanoplastics inhibited the larval locomotion by 22% during the last darkness period, and significantly reduced larvae body length by 6%, inhibited the acetylcholinesterase activity by 40%, and upregulated gfap, α1-tubulin, zfrho and zfblue gene expression significantly. When co-exposed with 2μg/L 17 α-ethynylestradiol (EE2), microplastics led to alleviation on EE2's inhibition effect on locomotion, which was probably due to the decreased freely dissolved EE2 concentration. However, though nanoplastics showed stronger adsorption ability for EE2, the hypoactivity phenomenon still existed in the nanoplastics co-exposure group. Moreover, when co-exposed with a higher concentration of EE2 (20μg/L), both plastics showed an enhanced effect on the hypoactivity. Principal component analysis was performed to reduce data dimensions and four principal components were reconstituted in terms of oxidative stress, body length, nervous and visual system related genes explaining 84% of total variance. Furthermore, oxidative damage and body length reduction were evaluated to be main reasons for the hypoactivity. Therefore, nanoplastics alone suppressed zebrafish larvae locomotor activity and both plastic particles can change the larvae swimming behavior when co-exposed with EE2. This study provides new insights into plastic particles' effects on zebrafish larvae, improving the understanding of their environmental risks to the aquatic environment.

  17. ALVIN investigation of an active propagating rift system, Galapagos 95.5° W

    USGS Publications Warehouse

    Hey, R.N.; Sinton, J.M.; Kleinrock, M.C.; Yonover, R.N.; MacDonald, K.C.; Miller, S.P.; Searle, R.C.; Christie, D.M.; Atwater, T.M.; Sleep, Norman H.; Johnson, H. Paul; Neal, C.A.

    1992-01-01

    ALVIN investigations have defined the fine-scale structural and volcanic patterns produced by active rift and spreading center propagation and failure near 95.5° W on the Galapagos spreading center. Behind the initial lithospheric rifting, which is propagating nearly due west at about 50 km m.y.−1, a triangular block of preexisting lithosphere is being stretched and fractured, with some recent volcanism along curving fissures. A well-organized seafloor spreading center, an extensively faulted and fissured volcanic ridge, develops ~ 10 km (~ 200,000 years) behind the tectonic rift tip. Regional variations in the chemical compositions of the youngest lavas collected during this program contrast with those encompassing the entire 3 m.y. of propagation history for this region. A maximum in degree of magmatic differentiation occurs about 9 km behind the propagating rift tip, in a region of diffuse rifting. The propagating spreading center shows a gentle gradient in magmatic differentiation culminating at the SW-curving spreading center tip. Except for the doomed rift, which is in a constructional phase, tectonic activity also dominates over volcanic activity along the failing spreading system. In contrast to the propagating rift, failing rift lavas show a highly restricted range of compositions consistent with derivation from a declining upwelling zone accompanying rift failure. The lithosphere transferred from the Cocos to the Nazca plate by this propagator is extensively faulted and characterized by ubiquitous talus in one of the most tectonically disrupted areas of seafloor known. The pseudofault scarps, where the preexisting lithosphere was rifted apart, appear to include both normal and propagator lavas and are thus more lithologically complex than previously thought. Biological communities, probably vestimentiferan tubeworms, occur near the top of the outer pseudofault scarp, although no hydrothermal venting was observed.

  18. Correlation of Conformational Changes and Protein Degradation with Loss of Lysozyme Activity Due to Chlorine Dioxide Treatment.

    PubMed

    Ooi, Beng Guat; Branning, Sharon Alyssa

    2016-12-13

    Chlorine dioxide (ClO2) is a potent oxidizing agent used for the treatment of drinking water and decontamination of facilities and equipment. The purpose of this research is to elucidate the manner in which ClO2 destroys proteins by studying the effects of ClO2 on lysozyme. The degree of enzyme activity lost can be correlated to the treatment time and levels of the ClO2 used. Lysozyme activity was drastically reduced to 45.3% of original enzyme activity when exposed to 4.3 mM ClO2 in the sample after 3 h. Almost all activities were lost in 3 h after exposure to higher ClO2 concentrations of up to 16.8 and 21.9 mM. Changes in protein conformation and amount as a result of ClO2 treatment were determined using the Raman spectroscopy and gel electrophoresis. Raman shifts and the alteration of spectral features observed in the ClO2-treated lysozyme samples are associated with loss of the α-helix secondary structure, tertiary structure, and disulfide bond. Progressive degradation of the denatured lysozyme by increasing levels of chlorine dioxide was also observed in gel electrophoresis. Hence, ClO2 can effectively cause protein denaturation and degradation resulting in loss of enzyme activity.

  19. The effects on community college student physics achievement and attitudes about learning physics due to inquiry-based laboratory activities versus cookbook laboratory activities

    NASA Astrophysics Data System (ADS)

    Nock, George Allen Brittingham

    The purpose of this quasi-experimental study was to determine the effects on community college student physics conceptual achievement and attitudes about learning physics due to the use of inquiry-based laboratory activities versus cookbook laboratory activities. An analysis of covariance (ANCOVA) was performed to test for differences in mean post-test Force Concept Inventory (FCI) score for two different types of physics lab instruction (IL versus CBL). Results of the ANCOVA, F (1, 35) = 0.761, p < 0.389, supported the null hypothesis that no significant difference was found in the post-test FCI scores of the two groups. An ANCOVA was performed to test for differences in mean post-test Mechanics Baseline Test (MBT) score for two different types of physics lab instruction (IL versus CBL)., however, the covariate and the dependent variable were shown to not be linearly related. Therefore, a one-way analysis of variance (ANOVA) was used to compare MBT scores. The results of the ANOVA, F (1, 36) = 0.066, p < 0.798, supported the null hypothesis that there was no significant difference in MBT scores of the two groups. A step-wise multiple linear regression was used to analyze the relationships between the FCI post-test score and the type of instruction, FCI pre-test score, and American College Test (ACT) science reasoning sub-scores. The FCI pre-test score and ACT science score were shown to be the best predictors of FCI post-test score. Another step-wise multiple linear regression was used to analyze the relationships between the MBT post-test score and type of instruction, MBT pre-test score, and ACT science reasoning sub-scores. The ACT Science sub-scores were determined to be the best predictor of MBT post-test score. An independent t-test was used to compare the mean lecture test grades for the lab groups taught using inquiry and cookbook methods. The mean lecture test scores of the inquiry-based lab group (M = 81.39, S.D. = 8.15) were found to be significantly

  20. Oral baclofen increases maximal voluntary neuromuscular activation of ankle plantar flexors in children with spasticity due to cerebral palsy.

    PubMed

    van Doornik, Johan; Kukke, Sahana; McGill, Kevin; Rose, Jessica; Sherman-Levine, Sara; Sanger, Terence D

    2008-06-01

    Although spasticity is a common symptom in children with cerebral palsy, weakness may be a much greater contributor to disability. We explore whether a treatment that reduces spasticity may also have potential benefit for improving strength. Ten children with cerebral palsy and spasticity in the ankle plantar flexor muscles were treated with oral baclofen for 4 weeks. We tested voluntary ability to activate ankle plantar flexor muscles using the ratio of the surface electromyographic signal during isometric maximal voluntary contraction to the M-wave during supramaximal electrical stimulation of the tibial nerve and tested muscle strength using maximal isometric plantar flexion torque. Mean maximal voluntary neuromuscular activation increased from 1.13 +/- 1.02 to 1.60 +/- 1.30 ( P < .05) after treatment, corresponding to an increase in 9 of 10 subjects. Mean maximal plantar flexion torque did not change. We conjecture that antispasticity agents could facilitate strength training by increasing the ability to voluntarily activate muscle.

  1. Active co-infection with HBV and/or HCV in South African HIV positive patients due for cancer therapy.

    PubMed

    Musyoki, Andrew M; Msibi, Thembeni L; Motswaledi, Mojakgomo H; Selabe, Selokela G; Monokoane, Tshweu S; Mphahlele, M Jeffrey

    2015-02-01

    Human immunodeficiency virus (HIV), Hepatitis B virus (HBV) and Hepatitis C virus (HCV) share routes of transmission. There is limited data on the incidence of active co-infection with HBV and/or HCV in cancer patients infected with HIV in Africa. This was a prospective study based on 34 patients with varied cancer diagnosis, infected with HIV and awaiting cancer therapy in South Africa. HIV viral load, CD4+ cell counts, Alanine-aminotransferase and aspartate aminotransferase levels were tested. Exposure to HBV and HCV was assessed serologically using commercial kits. Active HBV and/or HCV co-infection was detected using viral specific nested PCR assays. HCV 5'-UTR PCR products were sequenced to confirm active HCV infection. Active viral infection was detected in 64.7% of patients for HBV, 38.2% for HCV, and 29.4% for both HBV and HCV. Occult HBV infection was observed in 63.6% of the patients, while seronegative HCV infection was found in 30.8% of patients. In addition, CD4+ cell count < 350 cells/µl was not a risk factor for increased active HBV, HCV or both HBV and HCV co-infections. A total of 72.7%, 18.2% and 9.1% of the HCV sequences were assigned genotype 5, 1 and 4 respectively.The study revealed for the first time a high active HBV and/or HCV co-infection rate in cancer patients infected with HIV. The findings call for HBV and HCV testing in such patients, and where feasible, appropriate antiviral treatment be indicated, as chemotherapy or radiotherapy has been associated with reactivation of viral hepatitis and termination of cancer therapy.

  2. Poly (ADP-Ribose) Polymerase is Involved in the Repair of DNA Damage Due to Sulfur Mustard by a Mechanism Other Than DNA Ligase I Activation

    DTIC Science & Technology

    2004-11-16

    agents including sulfur mustard (SM). We observed concurrent activation of PARP and DNA ligase in SM-exposed human epidermal keratinocytes (HEK...Previous reports from other laboratories suggested that DNA ligase activation could be due to its modification by PARP. In humans, there are three distinct...DNA ligases, I, II and IV of which DNA ligase I participates in DNA replication and repair. By metabolically labeling HEK using 3H-adenosine

  3. Interruption pf physcial activity due to illness in the Lifestyle Interventions and Indepencence for Elders Pilot (LIFE-P) trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) was a trial to examine the effects of physical activity (PA) compared to a health education control on measures of disability in sedentary older adults. Medical suspensions were examined for the first 12 months of the trial in th...

  4. Ionospheric anomaly due to seismic activities - Part 2: Evidence from D-layer preparation and disappearance times

    NASA Astrophysics Data System (ADS)

    Chakrabarti, S. K.; Sasmal, S.; Chakrabarti, S.

    2010-08-01

    We show evidences for anomalous ionospheric behaviour in the signal of Indian navy VLF transmitting station named VTX due to earthquakes in the South Asian region. We concentrate on the variation of the D-layer preparation time (DLPT) and D-layer disappearance time (DLDT) in a period of sixteen months and study their average behaviors. We identify those days in which DLPT and DLDT exhibit significant deviations. Separately, we compute the energy release by earthquakes during this period and show that "anomalous VLF" days are associated with anomalous energy release. We find that the anomaly and the deviation of DLPT and DLDTs from the mean are linearly correlated. We discuss the predictability in this approach and compare with the terminator shift approach using the same set of data.

  5. Asymptomatic Congenital Hyperinsulinism due to a Glucokinase-Activating Mutation, Treated as Adrenal Insufficiency for Twelve Years

    PubMed Central

    Morishita, Kae; Kyo, Chika; Kosugi, Rieko; Ogawa, Tatsuo; Inoue, Tatsuhide

    2017-01-01

    Congenital hyperinsulinism (CHI) caused by a glucokinase- (GCK-) activating mutation shows autosomal dominant inheritance, and its severity ranges from mild to severe. A 43-year-old female with asymptomatic hypoglycemia (47 mg/dL) was diagnosed as partial adrenal insufficiency and the administration of hydrocortisone (10 mg/day) was initiated. Twelve years later, her 8-month-old grandchild was diagnosed with CHI. Heterozygosity of exon 6 c.590T>C (p.M197T) was identified in a gene analysis of GCK, which was also detected in her son and herself. The identification of GCK-activating mutations in hyperinsulinemic hypoglycemia patients may be useful for a deeper understanding of the pathophysiology involved and preventing unnecessary glucocorticoid therapy. PMID:28163940

  6. Theoretical Model of Drag Force Impact on a Model International Space Station (ISS) Satellite due to Solar Activity

    NASA Astrophysics Data System (ADS)

    Nwankwo, Victor U. J.; Chakrabarti, Sandip Kumar

    The International Space Station (ISS) is the single largest and most complex scientific and engineering space structure in human history. Its orbital parameters make it extremely vulnerable to severe atmospheric drag force. Complex interactions between solar energetic particles, ultraviolet (UV) radiation with atmosphere and geomagnetic field cause heating and subsequent expansion of the upper atmosphere. This condition increases drag on low Earth orbit satellites (LEOSs) and varies with current space weather conditions. In this work, we apply the NRLMSISE-00 empirical atmospheric density model, as a function of space environmental parameters, to model drag force impact on a model LEOS during variation of solar activity. Applying the resulting drag model on a model ISS satellite we observe that depending on the severity and/or stage of solar activity or cycle, a massive artificial satellite could experience orbit decay rate of up to 2.95km/month during solar maximum and up to 1km/month during solar minimum.

  7. Exposure estimation errors to nitrogen oxides on a population scale due to daytime activity away from home.

    PubMed

    Shafran-Nathan, Rakefet; Yuval; Levy, Ilan; Broday, David M

    2017-02-15

    Accurate estimation of exposure to air pollution is necessary for assessing the impact of air pollution on the public health. Most environmental epidemiology studies assign the home address exposure to the study subjects. Here, we quantify the exposure estimation error at the population scale due to assigning it solely at the residence place. A cohort of most schoolchildren in Israel (~950,000), age 6-18, and a representative cohort of Israeli adults (~380,000), age 24-65, were used. For each subject the home and the work or school addresses were geocoded. Together, these two microenvironments account for the locations at which people are present during most of the weekdays. For each subject, we estimated ambient nitrogen oxide concentrations at the home and work or school addresses using two air quality models: a stationary land use regression model and a dynamic dispersion-like model. On average, accounting for the subjects' work or school address as well as for the daily pollutant variation reduced the estimation error of exposure to ambient NOx/NO2 by 5-10ppb, since daytime concentrations at work/school and at home can differ significantly. These results were consistent regardless which air quality model as used and even for subjects that work or study close to their home. Yet, due to their usually short commute, assigning schoolchildren exposure solely at their residential place seems to be a reasonable estimation. In contrast, since adults commute for longer distances, assigning exposure of adults only at the residential place has a lower correlation with the daily weighted exposure, resulting in larger exposure estimation errors. We show that exposure misclassification can result from not accounting for the subjects' time-location trajectories through the spatiotemporally varying pollutant concentrations field.

  8. Comparison of polar cap electron density enhancement due to solar illumination and geomagnetic activity as measured by IMAGE/RPI

    NASA Astrophysics Data System (ADS)

    Nsumei, P.; Reinisch, B.; Song, P.; Tu, J.; Huang, X.

    2007-12-01

    Polar cap electron density (Ne) measurements made between the years 2000 - 2005 by the radio plasma imager (RPI) on board the IMAGE spacecraft are used to study the density enhancements resulting from changes in solar illumination and geomagnetic activity level. This study covers a geocentric distance, R = 1.4 - 5.0 RE and the polar cap is defined by an empirical boundary model that takes into account the dynamic nature of the location and size of the polar cap. The average polar cap electron density profile depends on geomagnetic activity level e.g., measured by the Kp index and solar illumination (solar zenith angle) at the footprints of the geomagnetic field lines. Our analysis of RPI Ne data shows that increase in geomagnetic activity leads to an enhancement in Ne. This enhancement in Ne is found to increase with altitude. At geocentric distance of R = 4.5 RE, an increase in the geomagnetic activity level from Kp < 2 to ~5 results in an Ne increase by a factor of ~5. On the other hand, a strong solar illumination control of Ne at lower altitudes, and not at higher is observed. At geocentric distance of ~ 2 RE, the average Ne is larger on the sunlit side than on the dark side by a factor of 3 - 4 both for quiet and disturbed conditions. At geocentric distance of about 2.5 RE the effects of these two factors on Ne appear to be comparable. Similar to previous polar cap density models, a functional representation of RPI Ne that takes the form of a power law is proposed. While in the previous Ne functional representations the power index is a constant, the power index in our representation of Ne distribution is found to correlate with (and hence is a function of) the Kp index and the solar zenith angle (SZA).

  9. Prevalence and work-related risk factors for reduced activities and absenteeism due to low back symptoms.

    PubMed

    Widanarko, Baiduri; Legg, Stephen; Stevenson, Mark; Devereux, Jason; Eng, Amanda; 't Mannetje, Andrea; Cheng, Soo; Pearce, Neil

    2012-07-01

    Although quite a lot is known about the risk factors for low back symptoms (LBS), less is known about the risk factors for the consequences of LBS. A sample of 3003 men and women randomly selected from the New Zealand Electoral Roll, were interviewed by telephone about self reported physical, psychosocial, organizational, environmental factors and the consequences of LBS (i.e. self-reported reduced activities and absenteeism). The 12-month period prevalence of reduced activities and absenteeism were 18% and 9%, respectively. Lifting (OR 1.79 95% CI 1.16-2.77) increased the risk of reduced activities. Working in awkward/tiring positions (OR 2.11 95% CI 1.20-3.70) and in a cold/damp environment (OR 2.18 95% CI 1.11-4.28) increased the risk of absenteeism. Among those with LBS, reduced activities increased with working in a hot/warm environment (OR 2.14 95% CI 1.22-3.76) and absenteeism was increased with work in awkward/tiring positions (OR 2.06 95% CI 1.13-3.77), tight deadlines (OR 1.89 95% CI 1.02-3.50), and a hot/warm environment (OR 3.35 95% CI 1.68-6.68). Interventions to reduce the consequences of LBS should aim to reduce awkward/tiring positions, lifting and work in a cold/damp environment. For individuals with LBS, additional focus should be to reduce tight deadlines, and work in hot/warm environments.

  10. Increased Incidence of Urolithiasis and Bacteremia During Proteus mirabilis and Providencia stuartii Coinfection Due to Synergistic Induction of Urease Activity

    PubMed Central

    Armbruster, Chelsie E.; Smith, Sara N.; Yep, Alejandra; Mobley, Harry L. T.

    2014-01-01

    Background. Catheter-associated urinary tract infections (CaUTIs) are the most common hospital-acquired infections worldwide and are frequently polymicrobial. The urease-positive species Proteus mirabilis and Providencia stuartii are two of the leading causes of CaUTIs and commonly co-colonize catheters. These species can also cause urolithiasis and bacteremia. However, the impact of coinfection on these complications has never been addressed experimentally. Methods. A mouse model of ascending UTI was utilized to determine the impact of coinfection on colonization, urolithiasis, and bacteremia. Mice were infected with P. mirabilis or a urease mutant, P. stuartii, or a combination of these organisms. In vitro experiments were conducted to assess growth dynamics and impact of co-culture on urease activity. Results. Coinfection resulted in a bacterial load similar to monospecies infection but with increased incidence of urolithiasis and bacteremia. These complications were urease-dependent as they were not observed during coinfection with a P. mirabilis urease mutant. Furthermore, total urease activity was increased during co-culture. Conclusions. We conclude that P. mirabilis and P. stuartii coinfection promotes urolithiasis and bacteremia in a urease-dependent manner, at least in part through synergistic induction of urease activity. These data provide a possible explanation for the high incidence of bacteremia resulting from polymicrobial CaUTI. PMID:24280366

  11. Evidence of 131I and (134,137)Cs activities in Bordeaux, France due to the Fukushima nuclear accident.

    PubMed

    Perrot, F; Hubert, Ph; Marquet, Ch; Pravikoff, M S; Bourquin, P; Chiron, H; Guernion, P-Y; Nachab, A

    2012-12-01

    Following the Fukushima nuclear accident, low-background gamma spectrometry measurements were performed with HPGe detectors at the PRISNA platform located at the CENBG laboratory in Bordeaux, France. Different kinds of samples were collected and measured between March 26 and May 14, 2011. The first fission product observed was (131)I with maximum activity values of 2.4 mBq/m(3) in atmospheric dusts in air, 3.5 Bq/L in rain water, 15 Bq/kg in grass and 0.9 Bq/L in cow milk. The (134,137)Cs isotopes were also detected in air and in grass at a maximum level of 0.2 mBq/m(3) and 0.7 Bq/kg respectively, around one order of magnitude less than (131)I activity, but they were below detection limits in the other samples. All these activity values were consistent with others measured in France by IRSN and were well below those reported in May 1986 after the Chernobyl accident.

  12. Inversed relationship between CD44 variant and c-Myc due to oxidative stress-induced canonical Wnt activation

    SciTech Connect

    Yoshida, Go J. Saya, Hideyuki

    2014-01-10

    Highlights: •CD44 variant8–10 and c-Myc are inversely expressed in gastric cancer cells. •Redox-stress enhances c-Myc expression via canonical Wnt signal. •CD44v, but not CD44 standard, suppresses redox stress-induced Wnt activation. •CD44v expression promotes both transcription and proteasome degradation of c-Myc. •Inversed expression pattern between CD44v and c-Myc is often recognized in vivo. -- Abstract: Cancer stem-like cells express high amount of CD44 variant8-10 which protects cancer cells from redox stress. We have demonstrated by immunohistochemical analysis and Western blotting, and reverse-transcription polymerase chain reaction, that CD44 variant8-10 and c-Myc tend to show the inversed expression manner in gastric cancer cells. That is attributable to the oxidative stress-induced canonical Wnt activation, and furthermore, the up-regulation of the downstream molecules, one of which is oncogenic c-Myc, is not easily to occur in CD44 variant-positive cancer cells. We have also found out that CD44v8-10 expression is associated with the turn-over of the c-Myc with the experiments using gastric cancer cell lines. This cannot be simply explained by the model of oxidative stress-induced Wnt activation. CD44v8-10-positive cancer cells are enriched at the invasive front. Tumor tissue at the invasive area is considered to be composed of heterogeneous cellular population; dormant cancer stem-like cells with CD44v8-10 {sup high}/ Fbw7 {sup high}/ c-Myc {sup low} and proliferative cancer stem-like cells with CD44v8-10 {sup high}/ Fbw7 {sup low}/ c-Myc {sup high}.

  13. Structural Investigation of Alkali Activated Clay Minerals for Application in Water Treatment Systems

    NASA Astrophysics Data System (ADS)

    Bumanis, G.; Bajare, D.; Dembovska, L.

    2015-11-01

    Alkali activation technology can be applied for a wide range of alumo-silicates to produce innovative materials with various areas of application. Most researches focuse on the application of alumo-silicate materials in building industry as cement binder replacement to produce mortar and concrete [1]. However, alkali activation technology offers high potential also in biotechnologies [2]. In the processes where certain pH level, especially alkaline environment, must be ensured, alkali activated materials can be applied. One of such fields is water treatment systems where high level pH (up to pH 10.5) ensures efficient removal of water pollutants such as manganese [3]. Previous investigations had shown that alkali activation technology can be applied to calcined clay powder and aluminium scrap recycling waste as a foam forming agent to create porous alkali activated materials. This investigation focuses on the structural investigation of calcined kaolin and illite clay alkali activation processes. Chemical and mineralogical composition of both clays were determined and structural investigation of alkali activated materials was made by using XRD, DTA, FTIR analysis; the microstructure of hardened specimens was observed by SEM. Physical properties of the obtained material were determined. Investigation indicates the essential role of chemical composition of the clay used in the alkali activation process, and potential use of the obtained material in water treatment systems.

  14. 210Po and 210Pb Activity Concentrations in Cigarettes Produced in Vietnam and Their Estimated Dose Contribution Due to Smoking

    NASA Astrophysics Data System (ADS)

    Tran, Thuy-Ngan N.; Le, Cong-Hao; Chau, Van-Tao

    Smoking cigarettes contributes significantly to the increase of radiation in human body because 210Po and 210Pb exist relatively high in tobacco leaves. Therefore, these two radioisotopes in eighteen of the most frequently sold cigarette brands produced in Vietnam were examined in this study. 210Po was determined by alpha spectroscopy using a passivated implanted planar silicon (PIPS) detector after a procedure including radiochemical separation and spontaneous deposition of polonium on a copper disc (the deposition efficiency of 210Po on a copper disc was approximately 94%). Sequentially, 210Pb was determined through the ingrowth of 210Po after storing the sample solutions for approximately six months. The activity concentrations of 210Po in cigarettes ranged from 13.8 to 82.6 mBq/cigarette (the mean value was 26.4 mBq/cigarette) and the activity concentrations of 210Pb in cigarettes ranged from 13.9 to 78.8 mBq/cigarette (the mean value was 25.8 mBq/cigarette). The annual committed effective dose for smokers who smoke one pack per day was also estimated to be 295.4 µSv/year (223.0 µSv/year and 72.4 µSv/year from 210Po and 210Pb, respectively). These indicated that smoking increased the risk of developing lung cancer was approximately 60 times greater for smokers than for non-smokers.

  15. In the Early Stages of Diabetes, Rat Retinal Mitochondria Undergo Mild Uncoupling due to UCP2 Activity

    PubMed Central

    Osorio-Paz, Ixchel; Uribe-Carvajal, Salvador; Salceda, Rocío

    2015-01-01

    In order to maintain high transmembrane ionic gradients, retinal tissues require a large amount of energy probably provided by a high rate of both, glycolysis and oxidative phosphorylation. However, little information exists on retinal mitochondrial efficiency. We analyzed the retinal mitochondrial activity in ex vivo retinas and in isolated mitochondria from normal rat retina and from short-term streptozotocin-diabetic rats. In normal ex vivo retinas, increasing glucose concentrations from 5.6mM to 30mM caused a four-fold increase in glucose accumulation and CO2 production. Retina from diabetic rats accumulated similar amounts of glucose. However, CO2 production was not as high. Isolated mitochondria from normal rat retina exhibited a resting rate of oxygen consumption of 14.6 ± 1.1 natgO (min.mg prot)-1 and a respiratory control of 4.0. Mitochondria from 7, 20 and 45 days diabetic rats increased the resting rate of oxygen consumption and the activity of the electron transport complexes; under these conditions the mitochondrial transmembrane potential decreased. In spite of this, the ATP synthesis was not modified. GDP, an UCP2 inhibitor, increased mitochondrial membrane potential and superoxide production in controls and at 45 days of diabetes. The role of UCP2 is discussed. The results suggest that at the early stage of diabetes we studied, retinal mitochondria undergo adaptations leading to maintain energetic requirements and prevent oxidative stress. PMID:25951172

  16. In the Early Stages of Diabetes, Rat Retinal Mitochondria Undergo Mild Uncoupling due to UCP2 Activity.

    PubMed

    Osorio-Paz, Ixchel; Uribe-Carvajal, Salvador; Salceda, Rocío

    2015-01-01

    In order to maintain high transmembrane ionic gradients, retinal tissues require a large amount of energy probably provided by a high rate of both, glycolysis and oxidative phosphorylation. However, little information exists on retinal mitochondrial efficiency. We analyzed the retinal mitochondrial activity in ex vivo retinas and in isolated mitochondria from normal rat retina and from short-term streptozotocin-diabetic rats. In normal ex vivo retinas, increasing glucose concentrations from 5.6 mM to 30 mM caused a four-fold increase in glucose accumulation and CO2 production. Retina from diabetic rats accumulated similar amounts of glucose. However, CO2 production was not as high. Isolated mitochondria from normal rat retina exhibited a resting rate of oxygen consumption of 14.6 ± 1.1 natgO (min.mg prot)(-1) and a respiratory control of 4.0. Mitochondria from 7, 20 and 45 days diabetic rats increased the resting rate of oxygen consumption and the activity of the electron transport complexes; under these conditions the mitochondrial transmembrane potential decreased. In spite of this, the ATP synthesis was not modified. GDP, an UCP2 inhibitor, increased mitochondrial membrane potential and superoxide production in controls and at 45 days of diabetes. The role of UCP2 is discussed. The results suggest that at the early stage of diabetes we studied, retinal mitochondria undergo adaptations leading to maintain energetic requirements and prevent oxidative stress.

  17. Cortical activation and inter-hemispheric sensorimotor coherence in individuals with arm dystonia due to childhood stroke

    PubMed Central

    Kukke, Sahana N.; de Campos, Ana Carolina; Damiano, Diane; Alter, Katharine E.; Patronas, Nicholas; Hallett, Mark

    2014-01-01

    Objective Dystonia is a disabling motor disorder often without effective therapies. To better understand the genesis of dystonia after childhood stroke, we analyzed electroencephalographic (EEG) recordings in this population. Methods Resting spectral power of EEG signals over bilateral sensorimotor cortices (Powrest), resting inter-hemispheric sensorimotor coherence (Cohrest), and task-related changes in power (TRPow) and coherence (TRCoh) during wrist extension were analyzed in individuals with dystonia (age 20±3 years) and healthy volunteers (age 17±5 years). Results Ipsilesional TRPow decrease was significantly lower in patients than controls during the more affected wrist task. Force deficits of the affected wrist correlated with reduced alpha TRPow decrease on the ipsilesional and not the contralesional hemisphere. Cohrest was significantly lower in patients than controls, and correlated with more severe dystonia and poorer hand function. Powrest and TRCoh were similar between groups. Conclusions The association between weakness and cortical activation during wrist extension highlights the importance of ipsilesional sensorimotor activation on function. Reduction of Cohrest in patients reflects a loss of inter-hemispheric connectivity that may result from structural changes and neuroplasticity, potentially contributing to the development of dystonia. Significance Cortical and motor dysfunction are correlated in patients with childhood stroke and may in part explain the genesis of dystonia. PMID:25499610

  18. Is dorsal anterior cingulate cortex activation in response to social exclusion due to expectancy violation? An fMRI study

    PubMed Central

    Kawamoto, Taishi; Onoda, Keiichi; Nakashima, Ken'ichiro; Nittono, Hiroshi; Yamaguchi, Shuhei; Ura, Mitsuhiro

    2012-01-01

    People are typically quite sensitive about being accepted or excluded by others. Previous studies have suggested that the dorsal anterior cingulate cortex (dACC) is a key brain region involved in the detection of social exclusion. However, this region has also been shown to be sensitive to non-social expectancy violations. We often expect other people to follow an unwritten rule in which they include us as they would expect to be included, such that social exclusion likely involves some degree of expectancy violation. The present event-related functional magnetic resonance imaging (fMRI) study sought to separate the effects of expectancy violation from those of social exclusion, such that we employed an “overinclusion” condition in which a player was unexpectedly overincluded in the game by the other players. With this modification, we found that the dACC and right ventrolateral prefrontal cortex (rVLPFC) were activated by exclusion, relative to overinclusion. In addition, we identified a negative correlation between exclusion-evoked brain activity and self-rated social pain in the rVLPFC, but not in the dACC. These findings suggest that the rVLPFC is critical for regulating social pain, whereas the dACC plays an important role in the detection of exclusion. The neurobiological basis of social exclusion is different from that of mere expectancy violation. PMID:22866035

  19. Stochastic simulation of fission product activity in primary coolant due to fuel rod failures in typical PWRs under power transients

    NASA Astrophysics Data System (ADS)

    Iqbal, M. Javed; Mirza, Nasir M.; Mirza, Sikander M.

    2008-01-01

    During normal operation of PWRs, routine fuel rods failures result in release of radioactive fission products (RFPs) in the primary coolant of PWRs. In this work, a stochastic model has been developed for simulation of failure time sequences and release rates for the estimation of fission product activity in primary coolant of a typical PWR under power perturbations. In the first part, a stochastic approach is developed, based on generation of fuel failure event sequences by sampling the time dependent intensity functions. Then a three-stage model based deterministic methodology of the FPCART code has been extended to include failure sequences and random release rates in a computer code FPCART-ST, which uses state-of-the-art LEOPARD and ODMUG codes as its subroutines. The value of the 131I activity in primary coolant predicted by FPCART-ST code has been found in good agreement with the corresponding values measured at ANGRA-1 nuclear power plant. The predictions of FPCART-ST code with constant release option have also been found to have good agreement with corresponding experimental values for time dependent 135I, 135Xe and 89Kr concentrations in primary coolant measured during EDITHMOX-1 experiments.

  20. Estimation of landslides activities evolution due to land-use and climate change in a Pyrenean valley

    NASA Astrophysics Data System (ADS)

    Vandromme, Rosalie; Bernardie, Séverine; Houet, Thomas; Grémont, Marine; Grandjean, Gilles; Thiery, Yannick

    2016-04-01

    Global changes would have impacts worldwide, but their effects should be even more exacerbated in areas particularly vulnerable. Mountainous areas are among these vulnerable territories. Ecological systems are often at a fragile equilibrium, socio-economical activities are often climate-dependent and climate-driven natural hazards can be a major threat for human activities. In order to estimate the capacity of such mountainous valleys to face global changes (climate, but also climate- and human- induced land-use changes), it is necessary to be able to evaluate the evolution of the different threats. The present work shows a method to evaluate the influences of the evolution of both vegetation cover and climate on landslides activities over a whole valley until 2100, to propose adequate solutions for current and future forestry management. Firstly, the assessment of future land use is addressed through the construction of four prospective socio-economic scenarios up to 2050 and 2100, which are then spatially validated and modeled with LUCC models. Secondly, the climate change inputs of the project correspond to 2 scenarios of emission of greenhouse gases. The used simulations available on the portal DRIAS (http://www.drias-climat.fr) were performed with the GHG emissions scenarios (RCP: Representative concentration pathways, according to the standards defined by the GIEC) RCP 4.5 and RCP 8.5. The impact of land use and climate change is then addressed through the use of these scenarios into hazards computations. For that we use a large-scale slope stability assessment tool ALICE which combines a mechanical stability model (using finite slope analysis), a vegetation module which interfere with the first model, to take into account the effects of vegetation on the mechanical soil properties (cohesion and over-load), and an hydrogeological model. All these elements are interfaced within a GIS-based solution. In that way, future changes in temperature, precipitation and

  1. Simulation suggests that rapid activation of social distancing can arrest epidemic development due to a novel strain of influenza

    PubMed Central

    Kelso, Joel K; Milne, George J; Kelly, Heath

    2009-01-01

    Background Social distancing interventions such as school closure and prohibition of public gatherings are present in pandemic influenza preparedness plans. Predicting the effectiveness of intervention strategies in a pandemic is difficult. In the absence of other evidence, computer simulation can be used to help policy makers plan for a potential future influenza pandemic. We conducted simulations of a small community to determine the magnitude and timing of activation that would be necessary for social distancing interventions to arrest a future pandemic. Methods We used a detailed, individual-based model of a real community with a population of approximately 30,000. We simulated the effect of four social distancing interventions: school closure, increased isolation of symptomatic individuals in their household, workplace nonattendance, and reduction of contact in the wider community. We simulated each of the intervention measures in isolation and in several combinations; and examined the effect of delays in the activation of interventions on the final and daily attack rates. Results For an epidemic with an R0 value of 1.5, a combination of all four social distancing measures could reduce the final attack rate from 33% to below 10% if introduced within 6 weeks from the introduction of the first case. In contrast, for an R0 of 2.5 these measures must be introduced within 2 weeks of the first case to achieve a similar reduction; delays of 2, 3 and 4 weeks resulted in final attack rates of 7%, 21% and 45% respectively. For an R0 of 3.5 the combination of all four measures could reduce the final attack rate from 73% to 16%, but only if introduced without delay; delays of 1, 2 or 3 weeks resulted in final attack rates of 19%, 35% or 63% respectively. For the higher R0 values no single measure has a significant impact on attack rates. Conclusion Our results suggest a critical role of social distancing in the potential control of a future pandemic and indicate that such

  2. Reduced female mating receptivity and activation of oviposition in two Callosobruchus species due to injection of biogenic amines.

    PubMed

    Yamane, Takashi; Miyatake, Takahisa

    2010-03-01

    Analyses of proximate mechanisms that control mating and oviposition behaviours in insects are important because they link behavioural ecology and physiology. Recently, seed beetles have been used as models to study evolution of female multiple mating and cost of reproduction including mating. In the present study, we investigated the effects of biogenic amines into the abdomens of females of two Callosobruchus species, Callosobruchus chinensis and Callosobruchus maculatus, on mating receptivity and oviposition behaviour. In C. chinensis, injection of octopamine and tyramine reduced receptivity to mating and tyramine and serotonin increased the number of eggs laid. Similarly, injection of tyramine reduced the receptivity of females and increased the number of eggs laid by females of C. maculatus. These results show the possibility that biogenic amines control mating receptivity and oviposition behaviour in females of two Callosobruchus species.

  3. Red colouration in apple fruit is due to the activity of the MYB transcription factor, MdMYB10.

    PubMed

    Espley, Richard V; Hellens, Roger P; Putterill, Jo; Stevenson, David E; Kutty-Amma, Sumathi; Allan, Andrew C

    2007-02-01

    Anthocyanin concentration is an important determinant of the colour of many fruits. In apple (Malus x domestica), centuries of breeding have produced numerous varieties in which levels of anthocyanin pigment vary widely and change in response to environmental and developmental stimuli. The apple fruit cortex is usually colourless, although germplasm does exist where the cortex is highly pigmented due to the accumulation of either anthocyanins or carotenoids. From studies in a diverse array of plant species, it is apparent that anthocyanin biosynthesis is controlled at the level of transcription. Here we report the transcript levels of the anthocyanin biosynthetic genes in a red-fleshed apple compared with a white-fleshed cultivar. We also describe an apple MYB transcription factor, MdMYB10, that is similar in sequence to known anthocyanin regulators in other species. We further show that this transcription factor can induce anthocyanin accumulation in both heterologous and homologous systems, generating pigmented patches in transient assays in tobacco leaves and highly pigmented apple plants following stable transformation with constitutively expressed MdMYB10. Efficient induction of anthocyanin biosynthesis in transient assays by MdMYB10 was dependent on the co-expression of two distinct bHLH proteins from apple, MdbHLH3 and MdbHLH33. The strong correlation between the expression of MdMYB10 and apple anthocyanin levels during fruit development suggests that this transcription factor is responsible for controlling anthocyanin biosynthesis in apple fruit; in the red-fleshed cultivar and in the skin of other varieties, there is an induction of MdMYB10 expression concurrent with colour formation during development. Characterization of MdMYB10 has implications for the development of new varieties through classical breeding or a biotechnological approach.

  4. Detailed investigation of the phase transition in KxP4W8O32 and experimental arguments for a charge density wave due to hidden nesting

    NASA Astrophysics Data System (ADS)

    Kolincio, Kamil; Pérez, Olivier; Hébert, Sylvie; Fertey, Pierre; Pautrat, Alain

    2016-06-01

    Detailed structural and magnetotransport properties of monophosphate tungsten bronze Kx(PO2)4(WO3)8 single crystals are reported. Both galvanomagnetic and thermal properties are shown to be consistent with a charge density wave electronic transition due to hidden nesting of the quasi-1D portion of the Fermi surface. We also observe the enhancement of electronic anisotropy due to reconstruction of the Fermi surface at the Peierls transition. The resistivity presents a thermal hysteresis suggesting a first-order nature characteristic of a strong-coupling scenario. However, other measurements such as the change of carrier density demonstrate a second-order Peierls scenario with weak-coupling features. We suggest that the structural transition driven by the residual strain in the K-P-O environment is responsible for the resistivity hysteresis and modifies the Fermi surface which then helps the rise to the second-order Peierls instability.

  5. Maintenance of genetic variation in human personality: testing evolutionary models by estimating heritability due to common causal variants and investigating the effect of distant inbreeding.

    PubMed

    Verweij, Karin J H; Yang, Jian; Lahti, Jari; Veijola, Juha; Hintsanen, Mirka; Pulkki-Råback, Laura; Heinonen, Kati; Pouta, Anneli; Pesonen, Anu-Katriina; Widen, Elisabeth; Taanila, Anja; Isohanni, Matti; Miettunen, Jouko; Palotie, Aarno; Penke, Lars; Service, Susan K; Heath, Andrew C; Montgomery, Grant W; Raitakari, Olli; Kähönen, Mika; Viikari, Jorma; Räikkönen, Katri; Eriksson, Johan G; Keltikangas-Järvinen, Liisa; Lehtimäki, Terho; Martin, Nicholas G; Järvelin, Marjo-Riitta; Visscher, Peter M; Keller, Matthew C; Zietsch, Brendan P

    2012-10-01

    Personality traits are basic dimensions of behavioral variation, and twin, family, and adoption studies show that around 30% of the between-individual variation is due to genetic variation. There is rapidly growing interest in understanding the evolutionary basis of this genetic variation. Several evolutionary mechanisms could explain how genetic variation is maintained in traits, and each of these makes predictions in terms of the relative contribution of rare and common genetic variants to personality variation, the magnitude of nonadditive genetic influences, and whether personality is affected by inbreeding. Using genome-wide single nucleotide polymorphism (SNP) data from > 8000 individuals, we estimated that little variation in the Cloninger personality dimensions (7.2% on average) is due to the combined effect of common, additive genetic variants across the genome, suggesting that most heritable variation in personality is due to rare variant effects and/or a combination of dominance and epistasis. Furthermore, higher levels of inbreeding were associated with less socially desirable personality trait levels in three of the four personality dimensions. These findings are consistent with genetic variation in personality traits having been maintained by mutation-selection balance.

  6. Morphodynamics of Travertine Dam/Waterfall Growth due to the Interaction of Biological Activity, Water Flow and Limestone Emplacement

    NASA Astrophysics Data System (ADS)

    Izumi, N.; Parker, G.

    2012-12-01

    Plitvice Lakes in Croatia are characterized by a step-like train of lakes and waterfalls. The waterfalls are located at the crests of naturally-emplaced dams. The top of each dam grows upward at the rate of a few millimeters per year. It is thought that the upward growth of these dams is caused by the interaction of water flow and biological activity, resulting in the precipitation of dissolved limestone. Dam evolution is initiated by the growth of mosses that favor swift, shallow water. Bacteria that inhabit the roots of the moss excrete solid limestone (travertine) from the water. The limestone fossilizes the moss, and then more moss grows on top of the travertine deposit. In this way, the natural dam can grow over to 10 m high, impounding the water behind it to form a lake. We propose a simple model to explain the formation of natural limestone dams by the interaction between water flow and biologically-mediated travertine deposition. We assume for simplicity that light is the only factor determining the growth of moss, which is then colonized by travertine-emplacing bacteria. We also assume that the water is saturated with dissolved limestone, so that the process is not limited by limestone availability. Photosynthesis, and thus the growth rate of moss are crudely approximated as decreasing linearly with depth. We employ the shallow water equations to describe water flow over the dam. In order to obtain a profile of permanent form for a dam migrating upward and downstream at constant speed, we solve the problem in a moving coordinate system. When water flows over the dam, it is accelerated in the streamwise direction, and the water surface forms a backwater curve. The flow regime changes from Froude-subcritical to Froude-supercritical at a point slightly downstream of the crest of the dam. Farther downstream, the flow attains a threshold velocity beyond which moss is detached. This threshold point defines the downstream end of the active part of the dam. The

  7. Waves on the Great Lakes. Teacher Guide and Activity Book. OEAGLS Investigation No. 27.

    ERIC Educational Resources Information Center

    Keir, John; Mayer, Victor J.

    This document contains a student guide and a teacher guide on the topic of waves. The investigation includes three activities which lead students to an understanding of how waves are formed and how they move in water. Activity A introduces students to the parts of a wave. A demonstration using a stream table leads them to discover different…

  8. Teachers' Beliefs Related to Activity Play in the Preschool Setting: A Phenomenological Investigation

    ERIC Educational Resources Information Center

    Pisha, Lorelei Emma

    2012-01-01

    The purpose of the present study was to investigate how early childhood teachers working in Head Start programs made meaning of preschool-age children's physical activity play by exploring their personal childhood and professional experiences with physical activity play. The study was conducted to contribute research-based recommendations for…

  9. Storm Surges. Teacher Guide and Activity Book. OEAGLS Investigation No. 25.

    ERIC Educational Resources Information Center

    Keir, John; Mayer, Victor J.

    This investigation is designed to help students understand storm surges on Lake Erie. Activity A includes experiments and discussions intended to help students understand what causes storm surges on Lake Erie. Activity B considers how storm surges affect water levels and, in turn, coastal areas. The student booklet contains questions, experiments,…

  10. Investigating the Effectiveness of an Analogy Activity in Improving Students' Conceptual Change for Solution Chemistry Concepts

    ERIC Educational Resources Information Center

    Calik, Muammer; Ayas, Alipasa; Coll, Richard K.

    2009-01-01

    This paper reports on an investigation on the use of an analogy activity and seeks to provide evidence of whether the activity enables students to change alternative conceptions towards views more in accord with scientific views for aspects of solution chemistry. We were also interested in how robust any change was and whether these changes in…

  11. CacyBP/SIP inhibits Doxourbicin-induced apoptosis of glioma cells due to activation of ERK1/2.

    PubMed

    Tang, Yuan; Zhan, Wenjian; Cao, Tong; Tang, Tianjin; Gao, Yong; Qiu, Zhichao; Fu, Chunling; Qian, Fengyuan; Yu, Rutong; Shi, Hengliang

    2016-03-01

    Calcyclin-binding protein or Siah-1-interacting protein (CacyBP/SIP) was previously reported to promote the proliferation of glioma cells. However, the effect of CacyBP/SIP on apoptosis of glioma is poorly understood. Here, our study shows that CacyBP/SIP plays a role in inhibiting doxorubicin (DOX) induced apoptosis of glioma cells U251 and U87. Overexpression of CacyBP/SIP obviously suppressed the DOX-induced cell apoptosis. On the contrary, silencing of CacyBP/SIP significantly promoted it. Further investigation indicated that inhibition of apoptosis by CacyBP/SIP was relevant to its nuclear translocation in response to the DOX treatment. Importantly, we found that the level of p-ERK1/2 in nuclei was related to the nuclear accumulation of CacyBP/SIP. Finally, the role of CacyBP/SIP was confirmed in vivo in a mouse model with the cell line stably silencing CacyBP/SIP. Taken together, our results suggest that CacyBP/SIP plays an important role in inhibiting apoptosis of glioma cells which might be mediated by ERK1/2 signaling pathway, which will provide some guidance for the treatment of glioma.

  12. [Daptomycin: revitalizing a former drug due to the need of new active agents against grampositive multiresistant bacterias].

    PubMed

    Hernández Martí, V; Romá Sánchez, E; Salavert Lletí, M; Bosó Ribelles, V; Poveda Andrés, J L

    2007-09-01

    The development of mechanisms of resistance of many Gram-positive bacterial strains that cause complicated skin and soft tissue infections, as well as sepsis and bacteremia, has necessitated the search for new drugs that will improve treatment strategies. Daptomycin is a cyclic lipopeptide antibacterial that was launched for the treatment of complicated skin and soft tissue infections caused by Gram-positive organisms. The drug's mechanism of action is different from that of any other antibiotic. It binds to bacterial membranes and causes a rapid depolarization of membrane potential. This loss of membrane potential causes inhibition of protein, DNA and RNA synthesis, which results in bacterial cell death. The in vitro spectrum of activity of daptomycin encompasses most clinically relevant aerobic Gram-positive pathogenic bacteria. Compared to other antibiotics with a similar antibacterial spectrum, daptomycin does not cause nephrotoxicity. Taking these and other characteristics into consideration, daptomycin appears to be a good alternative to other drugs used in the treatment of complicated skin and soft tissue infections and in Gram-positive bacteremial infections.

  13. Extra dose due to extravehicular activity during the NASA4 mission measured by an on-board TLD system

    NASA Technical Reports Server (NTRS)

    Deme, S.; Apathy, I.; Hejja, I.; Lang, E.; Feher, I.

    1999-01-01

    A microprocessor-controlled on-board TLD system, 'Pille'96', was used during the NASA4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the extra dose to two astronauts in the course of their extravehicular activity (EVA). For the EVA dose measurements, CaSO4:Dy bulb dosemeters were located in specially designed pockets of the ORLAN spacesuits. During an EVA lasting 6 h, the dose ratio inside and outside Mir was measured. During the EVA, Mir crossed the South Atlantic Anomaly (SAA) three times. Taking into account the influence of these three crossings the mean EVA/internal dose rate ratio was 3.2. Internal dose mapping using CaSO4:Dy dosemeters gave mean dose rates ranging from 9.3 to 18.3 microGy h-1 at locations where the shielding effect was not the same. Evaluation results of the high temperature region of LiF dosemeters are given to estimate the mean LET.

  14. Echicetin coated polystyrene beads: a novel tool to investigate GPIb-specific platelet activation and aggregation.

    PubMed

    Navdaev, Alexey; Subramanian, Hariharan; Petunin, Alexey; Clemetson, Kenneth J; Gambaryan, Stepan; Walter, Ulrich

    2014-01-01

    von Willebrand factor/ristocetin (vWF/R) induces GPIb-dependent platelet agglutination and activation of αIIbβ3 integrin, which also binds vWF. These conditions make it difficult to investigate GPIb-specific signaling pathways in washed platelets. Here, we investigated the specific mechanisms of GPIb signaling using echicetin-coated polystyrene beads, which specifically activate GPIb. We compared platelet activation induced by echicetin beads to vWF/R. Human platelets were stimulated with polystyrene beads coated with increasing amounts of echicetin and platelet activation by echicetin beads was then investigated to reveal GPIb specific signaling. Echicetin beads induced αIIbβ3-dependent aggregation of washed platelets, while under the same conditions vWF/R treatment led only to αIIbβ3-independent platelet agglutination. The average distance between the echicetin molecules on the polystyrene beads must be less than 7 nm for full platelet activation, while the total amount of echicetin used for activation is not critical. Echicetin beads induced strong phosphorylation of several proteins including p38, ERK and PKB. Synergistic signaling via P2Y12 and thromboxane receptor through secreted ADP and TxA2, respectively, were important for echicetin bead triggered platelet activation. Activation of PKG by the NO/sGC/cGMP pathway inhibited echicetin bead-induced platelet aggregation. Echicetin-coated beads are powerful and reliable tools to study signaling in human platelets activated solely via GPIb and GPIb-triggered pathways.

  15. Investigating biogeomorphic dynamics in the forefield of an actively retreating alpine glacier

    NASA Astrophysics Data System (ADS)

    Eichel, Jana; Schmidtlein, Sebastian; Dikau, Richard

    2013-04-01

    Glacier forefields are highly dynamic environments characterized by active paraglacial processes and simultaneous vegetation succession. Interest in these environments and their development has recently increased especially considering sediment delivery and natural hazards. While the dynamics are accelerating due to recent climate change, interactions between vegetation and geomorphic processes and components and the resulting patterns are only partly understood. In recent studies, geomorphic-engineer species were identified in fluvial biogeomorphic systems and their influence can be considered as well known. Furthermore, the decadal biogeomorphic evolution and change in a floodplain were described using the concept of biogeomorphic succession. This detailed knowledge of biogeomorphic evolution is yet missing for glacier forefields, though they are supposed to be main focus areas in biogeomorphology as they are particularly affected by climate change. The presentation is related to an interdisciplinary project ('Biogeomorphic dynamics in the Turtmann glacier forefield, Valais, Switzerland', BIMODAL) set in the alpine environment of a glacier forefield in the Turtmann valley, Switzerland. Previous studies here show a paraglacial impact on vegetation succession that could be differentiated according to degree of geomorphic activity. Corresponding geomorphic activity and vegetation patterns were found and interpreted using the concepts of geomorphic-engineer species and biogeomorphic succession. Based on these results, the key targets of the project are (a) to analyse geomorphic-engineer species with their plant functional traits in relation to their impact on geomorphic processes and (b) to thoroughly investigate the mutual geomorphic and vegetation development (biogeomorphic succession). The combination of results from these micro- and mesoscale approaches serves (c) to understand the decadal development of the biogeomorphic glacier forefield system including

  16. Collaboration of local government and experts responding to increase in environmental radiation level due to the nuclear disaster: focusing on their activities and latest radiological discussion.

    PubMed

    Iimoto, T; Nunokawa, J; Fujii, H; Takashima, R; Hashimoto, M; Fukuhara, T; Yajima, T; Matsuzawa, H; Kurosawa, K; Yanagawa, Y; Someya, S

    2015-11-01

    Activities were introduced in Kashiwa city in the Tokyo metropolitan area to correspond to the elevated environmental radiation level after the disaster of the Fukushima Daiichi nuclear power plant. These were based on a strong cooperation between local governments and experts. Ambient dose rate and radioactivity of foodstuff produced inside of the city have been monitored. Representative ambient dose rates around living environments have almost already become their original levels of the pre-accident because of the decontamination activity, natural washout and effective half-lives of radioactivity. The internal annual dose due to radioactive cesium under the policy of 'Local Production for Local Consumption' is estimated as extremely low comparing the variation range due to natural radioactivity. Systematic survey around a retention basin has been started. All of these latest monitoring data would be one of the core information for the policy making as well as a cost-benefit discussion and risk communication.

  17. Radiation environment due to galactic and solar cosmic rays during manned mission to Mars in the periods between maximum and minimum solar activity cycles.

    PubMed

    Pissarenko, N F

    1994-10-01

    A possibility of a manned mission to Mars without exceeding the current radiation standards is very doubtful during the periods of minimum solar activity since the dose equivalent due to galactic cosmic rays exceeds currently recommended standards even inside a radiation shelter with an equivalent of 30 g cm-2 aluminum. The radiation situation at the time of maximum solar activity is determined by the occurrence of major solar proton events which are exceedingly difficult to forecast. This paper discusses the radiation environment during a manned mission to Mars in the years between minimum and maximum solar activity when the galactic cosmic ray intensity is considerably reduced, but the solar flare activity has not yet maximized.

  18. Gsα activity is reduced in erythrocyte membranes of patients with psedohypoparathyroidism due to epigenetic alterations at the GNAS locus.

    PubMed

    Zazo, Celia; Thiele, Susanne; Martín, Cesar; Fernandez-Rebollo, Eduardo; Martinez-Indart, Lorea; Werner, Ralf; Garin, Intza; Hiort, Olaf; Perez de Nanclares, Guiomar

    2011-08-01

    In pseudohypoparathyroidism (PHP), PTH resistance results from impairment of signal transduction of G protein-coupled receptors caused by a deficiency of the Gsα-cAMP signaling cascade due to diminished Gsα activity in maternally imprinted tissues. In PHP-Ia, inactivating mutations of the GNAS gene lead to haploinsufficiency in some tissues with biallelic expression, so in addition to PHP, Albright's hereditary osteodystrophy (AHO) is also present. In PHP-Ib, caused by methylation defects at the GNAS locus, diminished Gsα activity was thought to be limited to maternally imprinted tissues, such as the renal proximal tubule and the thyroid, leading to a lack of AHO. Recently, we demonstrated methylation defects in patients with AHO signs, indicating a connection between epigenetic changes and AHO. Our objective was to determine Gsα activity in erythrocyte membranes in patients with epigenetic defects at the GNAS locus compared to normal controls and patients with inactivating GNAS mutations. Gsα activity and expression, mutation of the GNAS locus, and methylation status were studied in patients with PHP and mild signs of AHO (PHP-Ia: 12; PHP-Ib: 17, of which 8 had some features of AHO). Then, we statistically compared the Gsα activity of the different PHP subtypes. Patients with methylation defects at the GNAS locus show a significant decrease in erythrocyte Gsα activity compared to normal controls (PHP-Ib versus controls, p < .001). This was significantly lower in patients with AHO signs (PHP-Ib + mild-AHO versus PHP-Ib, p < .05). Our research shows that PHP-Ia and PHP-Ib classification is not only overlapped genetically, as reported, but also in terms of Gsα activity. Reduced expression of GNAS due to methylation defects could downregulate Gsα activity in other tissues beyond those described and could also be causative of AHO.

  19. An investigation of the mimetic enzyme activity of two-dimensional Pd-based nanostructures.

    PubMed

    Wei, Jingping; Chen, Xiaolan; Shi, Saige; Mo, Shiguang; Zheng, Nanfeng

    2015-12-07

    In this work, we investigated the mimetic enzyme activity of two-dimensional (2D) Pd-based nanostructures (e.g. Pd nanosheets, Pd@Au and Pd@Pt nanoplates) and found that they possess intrinsic peroxidase-, oxidase- and catalase-like activities. These nanostructures were able to activate hydrogen peroxide or dissolved oxygen for catalyzing the oxidation of organic substrates, and decompose hydrogen peroxide to generate oxygen. More systematic investigations revealed that the peroxidase-like activities of these Pd-based nanomaterials were highly structure- and composition-dependent. Among them, Pd@Pt nanoplates displayed the highest peroxidase-like activity. Based on these findings, Pd-based nanostructures were applied for the colorimetric detection of H2O2 and glucose, and also the electro-catalytic reduction of H2O2. This work offers a promising prospect for the application of 2D noble metal nanostructures in biocatalysis.

  20. Heat Transfer Due to Unsteady Effects as Investigated in a High-Speed, Full-Scale, Fully-Cooled Turbine Vane and Rotor Stage

    DTIC Science & Technology

    2008-06-01

    the turbine stages of these engines have been established. The predominant method of cooling vane and rotor airfoils , having been used for over...INVESTIGATED IN A HIGH-SPEED, FULL-SCALE, FULLY-COOLED TURBINE VANE AND ROTOR STAGE THESIS Presented to the Faculty Department of Aeronautics and...reduce the effectiveness of film cooling in the vane and rotor stages of turbine engines . Even today, fairly little experimentation has been

  1. Neomorphic Mutations in PIK3R1 Confer Sensitivity to MAPK Inhibitors due to Activation of ERK and JNK Pathways | Office of Cancer Genomics

    Cancer.gov

    In a recent publication in Cancer Cell, CTD2 investigators discovered that a known cancer-associated gain-of-function alteration in phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) results in novel protein activity that confers sensitivity to mitogen-activated protein kinase (MAPK) inhibitors. The PIK3R1 gene encodes the p85α regulatory subunit of PIK3. Under normal conditions, p85α suppresses PIK3 mediated activation of downstream pathways that promote cell growth and survival.

  2. B7-H1 antibodies lose antitumor activity due to activation of p38 MAPK that leads to apoptosis of tumor-reactive CD8+ T cells

    PubMed Central

    Liu, Xin; Wu, Xiaosheng; Cao, Siyu; Harrington, Susan M.; Yin, Peng; Mansfield, Aaron S.; Dong, Haidong

    2016-01-01

    B7-H1 (aka PD-L1) blocking antibodies have been used in treatment of human cancers through blocking B7-H1 expressed by tumor cells; however, their impact on B7-H1 expressing tumor-reactive CD8+ T cells is still unknown. Here, we report that tumor-reactive CD8+ T cells expressing B7-H1 are functional effector cells. In contrast to normal B7-H1 blocking antibody, B7-H1 antibodies capable of activating p38 MAPK lose their antitumor activity by deleting B7-H1+ tumor-reactive CD8+ T cells via p38 MAPK pathway. B7-H1 deficiency or engagement with certain antibody results in more activation of p38 MAPK that leads to T cell apoptosis. DNA-PKcs is a new intracellular partner of B7-H1 in the cytoplasm of activated CD8+ T cells. B7-H1 suppresses p38 MAPK activation by sequestering DNA-PKcs in order to preserve T cell survival. Our findings provide a new mechanism of action of B7-H1 in T cells and have clinical implications in cancer immunotherapy when anti-B7-H1 (PD-L1) antibody is applied. PMID:27824138

  3. An fMRI Study Investigating Adolescent Brain Activation by Rewards and Feedback

    PubMed Central

    Choi, Won-Hee; Kim, Yeoung-Rang; Oh, Jong-Hyun; Lee, Sang-Ick; Shin, Chul-Jin; Kim, Sie-Kyeong; Ju, Gawon; Lee, Seungbok; Jo, Seongwoo; Ha, Tae Hyon

    2013-01-01

    Objective This study aimed to investigate the adolescent brain activation patterns in response to performance feedback (PF), social reward (SR) and monetary reward (MR) and their association with psychological factors. Methods Functional magnetic resonance imaging (fMRI) was performed while middle school boys (n=15) performed tests pertained to PF, SR and MR. The brain activation pattern in each condition was investigated, and the extent of brain activation in each of the three conditions was compared at once. Results The caudate and the dorsal prefrontal area were activated in all three conditions. Furthermore, the cuneus showed significantly greater activation in the PF condition than the SR or MR condition. And the self - related areas, such as the right precentral gyrus and paracenral lobule, were more activated in the SR condition than the PF or MR condition. The left middle frontal gyrus was more activated in the MR condition than the PF or SR condition. Conclusion Not only various reward stimuli but also feedback stimulus might commonly activate dorsal prefrontal and subcortical area in adolescents. Moreover, several different brain activation patterns were also observed in each condition. The results of this study could be applied to planning of learning and teaching strategy for adolescents in various ways. PMID:23482680

  4. Reflection seismic investigation of the geodynamically active West -Bohemia/Vogtland region

    NASA Astrophysics Data System (ADS)

    Mullick, N.; Buske, S.; Shapiro, S. A.; Wigger, P.

    2013-12-01

    The West Bohemia-Vogtland region in central Europe attracts much scientific interest due to recurrent earthquake swarms and continuous exhalation of CO2 dominated fluid from the subsurface. Seismological and geochemical studies reveal (1) significant upper mantle derived content of the emitted fluid, (2) an updoming of the MOHO below that area (3) possible existence of a magmatic fluid reservoir in the upper mantle and (4) fluid activity as a possible trigger for the swarm earthquakes. In this study the subsurface structure beneath the region is investigated by reprocessing the deep reflection seismic profile 9HR, which runs almost directly across the swarm area. The migrated image confirms the upwelling of the MOHO known from receiver function studies. Directly below one of the major gas escape centres, channel like fault structures are observed which seem to have their roots at the MOHO. They may represent deep reaching degassing channels that allow direct transport of mantle-derived fluid. The middle and lower crust appears highly fractured below the swarm area. This may result in mantle fluid ascending through the crust and then getting blocked in the crust. Such blockage could result in building up of an over-pressured fluid zone at the bottom of near surface rocks. After a critical state is reached, the over-pressured fluid may have sufficient energy to force its way above into near surface rocks and to trigger seismicity. Since the swarm seismicity is found to be restricted along a plane only, such intrusion might have taken place along a semi-permeable zone that extends from the fractured lower crust into the near surface rocks. A comparison of the spatio-temporal evolution of the recent swarms in the years 2000 and 2008 with the subsurface reflectivity shows that in both cases the swarm activity initiates at the upper edge of a highly diffuse reflectivity zone, moves upward, bends at a bright spot above and finally stops after travelling a few kilometers

  5. Reflection seismic investigation of the geodynamically active West-Bohemia/Vogtland region

    NASA Astrophysics Data System (ADS)

    Mullick, Nirjhar; Buske, Stefan

    2013-04-01

    The West Bohemia-Vogtland region in central Europe attracts much scientific interest due to recurrent earthquake swarms and continuous exhalation of CO2 dominated fluid from the subsurface. Seismological and geochemical studies reveal 1) significant upper mantle derived content of the emitted fluid, 2) an updoming of the MOHO below that area 3) possible existence of a magmatic fluid reservoir in the upper mantle and 4) fluid activity as a possible trigger for the swarm earthquakes. In this study the subsurface structure beneath the region is investigated by reprocessing the deep reflection seismic profile 9HR, which runs almost directly across the swarm area. The migrated image confirms the upwelling of the MOHO known from receiver function studies. Directly below one of the major gas escape centres, channel like fault structures are observed which seem to have their roots at the MOHO. They may represent deep reaching degassing channels that allow direct transport of mantle-derived fluid. The middle and lower crust appears highly fractured below the swarm area. This may result in mantle fluid ascending through the crust and then getting blocked in the crust. Such blockage could result in building up of an over-pressured fluid zone at the bottom of near surface rocks. After a critical state is reached, the over-pressured fluid may have sufficient energy to force its way above into near surface rocks and to trigger seismicity. Since the swarm seismicity is found to be restricted along a plane only, such intrusion might have taken place along a semi-permeable zone that extends from the fractured lower crust into the near surface rocks. A comparison of the spatio-temporal evolution of the recent swarms in the years 2000 and 2008 with the subsurface reflectivity shows that in both cases the swarm activity initiates at the upper edge of a highly diffuse reflectivity zone, moves upward, bends at a bright spot above and finally stops after travelling a few kilometers along

  6. Preliminary investigation of a sealed, remotely activated silver-zinc battery

    NASA Technical Reports Server (NTRS)

    Wheat, C. G.

    1977-01-01

    Methods necessary to provide a remotely activated, silver zinc battery capable of an extended activated stand while in a sealed condition were investigated. These requirements were to be accomplished in a battery package demonstrating an energy density of at least 35 watt hours per pound. Several methods of gas suppression were considered in view of the primary nature of this unit and utilized the electroplated dendritic zinc electrode. Amalgamation of the electrode provided the greatest suppression of gas at the zinc electrode. The approach to extending the activated stand capability of the remotely activated battery was through evaluation of three basic methods of remote, multi-cell activation; 1) the electrolyte manifold, 2) the gas manifold and 3) the individual cell. All three methods of activation can be incorporated into units which will meet the minimum energy density requirement.

  7. Unsteady loads due to propulsive lift configurations. Part D: The development of an experimental facility for the investigation of scaling effects on propulsive lift configurations

    NASA Technical Reports Server (NTRS)

    Haviland, J. K.; Herling, W. W.

    1978-01-01

    The design and construction of an experimental facility for the investigation of scaling effects in propulsive lift configurations are described. The facility was modeled after an existing full size NASA facility which consisted of a coaxial turbofan jet engine with a rectangular nozzle in a blown surface configuration. The flow field of the model facility was examined with and without a simulated wing surface in place at several locations downstream of the nozzle exit plane. Emphasis was placed on obtaining pressure measurements which were made with static probes and surface pressure ports connected via plastic tubing to condenser microphones for fluctuating measurements. Several pressure spectra were compared with those obtained from the NASA facility, and were used in a preliminary evaluation of scaling laws.

  8. Scanning electron microscopy in the investigation of the in vitro hemolytic activity of Trichomonas vaginalis.

    PubMed

    Rosset, Iveli; Tasca, Tiana; Tessele, Paola M; De Carli, Geraldo A

    2002-04-01

    The in vitro hemolytic activity of Trichomonas vaginalis has been previously demonstrated, but the mechanisms involved remain to be elucidated. In this work we used scanning electron microscopy to investigate the contact dependency of the hemolytic phenomenon caused by the parasites. The erythrocytes adhered to the parasites' surface and were phagocytosed. These observations suggest that the contact between T. vaginalis and erythrocytes may be an important mechanism in the injury caused to the erythrocytes. The hemolytic activity of T. vaginalis may be an efficient means of obtaining nutrients for the parasite and allow the investigation of the mechanism used by T. vaginalis to damage cellular membranes.

  9. An investigation of the energy balance of solar active regions using the ACRIM irradiance data

    NASA Technical Reports Server (NTRS)

    Petro, L. D.

    1986-01-01

    The detection of a significant correlation between the solar irradiance, corrected for flux deficit due to sunspots, and both the 205 nm flux and a photometric facular index were examined. A detailed analysis supports facular emission as the more likely source of correlation with the corrected radiance, rather then the error in sunspot correction. A computer program which simulates two dimensional convection in a compressible, stratified medium was investigated. Subroutines to calculate ionization and other thermodynamic variables were also completed.

  10. Investigation of frequency response of microwave active ring resonator based on ferrite film

    NASA Astrophysics Data System (ADS)

    Martynov, M. I.; Nikitin, A. A.; Ustinov, A. B.; Kalinikos, B. A.

    2016-11-01

    The complex transmission coefficient of active ring resonators based on ferrite-film delay lines was investigated both theoretically and experimentally. Influence of the parameters of the delay line on the transmission coefficients was investigated. It was shown that the resonant frequencies of the ring depend on the ferrite film thickness and the distance between spin-wave antennae. These dependences give possibility to control the shape of the transmission coefficient that in combination with magnetic tuning provide flexibility for microwave applications.

  11. Unsteady loads due to propulsive lift configurations. Part C: Development of experimental techniques for investigation of unsteady pressures behind a cold model jet

    NASA Technical Reports Server (NTRS)

    Haviland, J. K.; Schroeder, J. C.

    1978-01-01

    As part of an overall study of the scaling laws for the fluctuating pressures induced on the wings and flaps of STOL aircraft by jet engine impingement, an experimental investigation was made of the near field fluctuating pressures behind a cold circular jet, both when it was free and when it was impinging on a flat plate. Miniature static pressure probes were developed for measurements in the free jet and on the flat plate which were connected by plastic tubing to 1/8 inch microphones and acted as pressure transducers. Using a digital correlator together with an FFT program on the CDC 6400 computer, spectral densities, relative amplitudes, phase lags, and coherences were also obtained for the signals from pairs of these probes, and were used to calibrate these probes directly against microphones. This system of instrumentation was employed to obtain single point rms and third octave surveys of the static pressures in the free jet and on the surface of the plate.

  12. Investigation of avian influenza virus in poultry and wild birds due to novel avian-origin influenza A(H10N8) in Nanchang City, China.

    PubMed

    Ni, Xiansheng; He, Fenglan; Hu, Maohong; Zhou, Xianfeng; Wang, Bin; Feng, Changhua; Wu, Yumei; Li, Youxing; Tu, Junling; Li, Hui; Liu, Mingbin; Chen, Haiying; Chen, Shengen

    2015-01-01

    Multiple reassortment events within poultry and wild birds had resulted in the establishment of another novel avian influenza A(H10N8) virus, and finally resulted in human death in Nanchang, China. However, there was a paucity of information on the prevalence of avian influenza virus in poultry and wild birds in Nanchang area. We investigated avian influenza virus in poultry and wild birds from live poultry markets, poultry countyards, delivery vehicles, and wild-bird habitats in Nanchang. We analyzed 1036 samples from wild birds and domestic poultry collected from December 2013 to February 2014. Original biological samples were tested for the presence of avian influenza virus using specific primer and probe sets of H5, H7, H9, H10 and N8 subtypes by real-time RT-PCR. In our analysis, the majority (97.98%) of positive samples were from live poultry markets. Among the poultry samples from chickens and ducks, AIV prevalence was 26.05 and 30.81%, respectively. Mixed infection of different HA subtypes was very common. Additionally, H10 subtypes coexistence with N8 was the most prevalent agent during the emergence of H10N8. This event illustrated a long-term surveillance was so helpful for pandemic preparedness and response.

  13. An investigation into the vancomycin concentration in the cerebrospinal fluid due to vancomycin intraventricular administration in newborns: a study of 13 cases.

    PubMed

    Matsunaga, Nobuaki; Hisata, Ken; Shimizu, Toshiaki

    2015-06-01

    Treatment against shunt infection by transvenous antimicrobial treatment is difficult, with a high risk of relapse. Consequently, to maintain a sufficient cerebrospinal fluid (CSF) concentration, intraventricular administration is utilized in combination with the transvenous administration of vancomycin (VCM). Few studies have so far investigated the optimum administration dose for newborns and the concentration in the CSF. Therefore, we chronologically measured the VCM concentration in the CSF after VCM intraventricular administration in newborns and attempted to elucidate the optimum administration method.The participants consisted of newborns admitted to Juntendo University Neonatal intensive care unit from March 2007 to June 2011 who underwent interventricular shunting placement. VCM was intraventricularly administered to 10 patients for a total of 13 cases. The CSF concentration of VCM was chronologically measured at 12 to 120  hours following the intraventricular administration of VCM.The intraventricular administration groups with VCM of 20 (n = 6) and 10  mg (n = 2) had a high concentration in the CSF at 24  hours following administration (95-168  mg/L), with the concentration remaining high at 72  hours (13.2-72  mg/L). At the same time, in the 5  mg group (n = 5), the concentration in the CSF 24  hours following VCM administration was sufficiently maintained (33.2-62.9  mg/L), with a sufficient trough concentration still maintained at 72  hours (11.7-16.5  mg/L).The concentration in the CSF is prolonged in newborns, thus allowing a sufficient therapeutic range to be maintained even at an intraventricular administration of 5  mg. It is therefore believed that the monitoring of the CSF is very important regarding the administration interval because the VCM concentration in the CSF differs depending on the case.

  14. Anthropogenic wetlands due to over-irrigation of desert areas: a challenging hydrogeological investigation with extensive geophysical input from TEM and MRS measurements

    NASA Astrophysics Data System (ADS)

    Behroozmand, Ahmad Ali; Teatini, Pietro; Bjergsted Pedersen, Jesper; Auken, Esben; Tosatto, Omar; Vest Christiansen, Anders

    2017-03-01

    During the last century, many large irrigation projects were carried out in arid lands worldwide. Despite a tremendous increase in food production, a common problem when characterizing these zones is land degradation in the form of waterlogging. A clear example of this phenomenon is in the Nubariya depression in the Western Desert of Egypt. Following the reclamation of desert lands for agricultural production, an artificial brackish and contaminated pond started to develop in the late 1990s, which at present extends for about 2.5 km2. The available data provide evidence of a simultaneous general deterioration of the groundwater system. An extensive hydrogeophysical investigation was carried out in this challenging environment using magnetic resonance sounding (MRS) and ground-based time-domain electromagnetic (TEM) techniques with the following main objectives: (1) understanding the hydrological evolution of the area; (2) characterizing the hydrogeological setting; and (3) developing scenarios for artificial aquifer remediation and recharge. The integrated interpretation of the geophysical surveys provided a hydrogeological picture of the upper 100 m sedimentary setting in terms of both lithological distribution and groundwater quality. The information is then used to set up (1) a regional groundwater flow and (2) a local density-dependent flow and transport numerical model to reproduce the evolution of the aquifer system and develop a few scenarios for artificial aquifer recharge using the treated water provided by a nearby wastewater treatment plant. The research outcomes point to the hydrological challenges that emerge for the effective management of water resources in reclaimed desert areas, and they highlight the effectiveness of using advanced geophysical and modeling methodologies.

  15. A Model for Aryl Hydrocarbon Receptor-Activated Gene Expression Shows Potency and Efficacy Changes and Predicts Squelching Due to Competition for Transcription Co-Activators

    PubMed Central

    Simon, Ted W.; Budinsky, Robert A.; Rowlands, J. Craig

    2015-01-01

    A stochastic model of nuclear receptor-mediated transcription was developed based on activation of the aryl hydrocarbon receptor (AHR) by 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and subsequent binding the activated AHR to xenobiotic response elements (XREs) on DNA. The model was based on effects observed in cells lines commonly used as in vitro experimental systems. Following ligand binding, the AHR moves into the cell nucleus and forms a heterodimer with the aryl hydrocarbon nuclear translocator (ARNT). In the model, a requirement for binding to DNA is that a generic coregulatory protein is subsequently bound to the AHR-ARNT dimer. Varying the amount of coregulator available within the nucleus altered both the potency and efficacy of TCDD for inducing for transcription of CYP1A1 mRNA, a commonly used marker for activation of the AHR. Lowering the amount of available cofactor slightly increased the EC50 for the transcriptional response without changing the efficacy or maximal response. Further reduction in the amount of cofactor reduced the efficacy and produced non-monotonic dose-response curves (NMDRCs) at higher ligand concentrations. The shapes of these NMDRCs were reminiscent of the phenomenon of squelching. Resource limitations for transcriptional machinery are becoming apparent in eukaryotic cells. Within single cells, nuclear receptor-mediated gene expression appears to be a stochastic process; however, intercellular communication and other aspects of tissue coordination may represent a compensatory process to maintain an organism’s ability to respond on a phenotypic level to various stimuli within an inconstant environment. PMID:26039703

  16. The effects of skin tone on race-related amygdala activity: an fMRI investigation

    PubMed Central

    Denson, Thomas F.; Lickel, Brian; Lu, Zhong-Lin; Nandy, Anirvan; Maddox, Keith B.

    2007-01-01

    Previous work has shown differential amygdala response to African-American faces by Caucasian individuals. Furthermore, behavioral studies have demonstrated the existence of skin tone bias, the tendency to prefer light skin to dark skin. In the present study, we used functional magnetic resonance imaging (fMRI) to investigate whether skin tone bias moderates differential race-related amygdala activity. Eleven White participants viewed photographs of unfamiliar Black and White faces with varied skin tone (light, dark). Replicating past research, greater amygdala activity was observed for Black faces than White faces. Furthermore, dark-skinned targets elicited more amygdala activity than light-skinned targets. However, these results were qualified by a significant interaction between race and skin tone, such that amygdala activity was observed at equivalent levels for light- and dark-skinned Black targets, but dark-skinned White targets elicited greater amygdala activity than light-skinned White targets. PMID:18985117

  17. SU-E-T-667: Radiosensitization Due to Gold Nanoparticles: A Monte Carlo Cellular Dosimetry Investigation of An Expansive Parameter Space

    SciTech Connect

    Martinov, M; Thomson, R

    2015-06-15

    Purpose: To investigate dose enhancement to cellular compartments following gold nanoparticle (GNP) uptake in tissue, varying cell and tissue morphology, intra and extracellular GNP distribution, and source energy using Monte Carlo (MC) simulations. Methods: Models of single and multiple cells are developed for normal and cancerous tissues; cells (outer radii 5–10 µm) are modeled as concentric spheres comprising the nucleus (radii 2.5–7.5 µm) and cytoplasm. GNP distributions modeled include homogeneous distributions throughout the cytoplasm, variable numbers of GNP-containing endosomes within the cytoplasm, or distributed in a spherical shell about the nucleus. Gold concentrations range from 1 to 30 mg/g. Dose to nucleus and to cytoplasm for simulations including GNPs are compared to simulations without GNPs to compute Nuclear and Cytoplasm Dose Enhancement Factors (NDEF, CDEF). Photon source energies are between 20 keV and 1.25 MeV. Results: DEFs are highly sensitive to GNP intracellular distribution; for a 2.5 µm radius nucleus irradiated by a 30 keV source, NDEF varies from 1.2 for a single endosome containing all GNPs to 8.2 for GNPs distributed about the nucleus (7 mg/g). DEFs vary with cell dimensions and source energy: NDEFs vary from 2.5 (90 keV) to 8.2 (30 keV) for a 2.5 µm radius nucleus and from 1.1 (90 keV) to 1.3 (30 keV) for a 7.5 µm radius nucleus, both with GNPs in a spherical shell about the nucleus (7 mg/g). NDEF and CDEF are generally different within a single cell. For multicell models, the presence of gold within intervening tissues between source and target perturbs the fluence reaching cellular targets, resulting in DEF inhomogeneities within a population of irradiated cells. Conclusion: DEFs vary by an order of magnitude for different cell models, GNP distributions, and source energies, demonstrating the importance of detailed modelling for advancing GNP development for radiotherapy. Funding provided by the Natural Sciences and

  18. Young Children's Literacy in the Activity Space of the Library: A Geosemiotic Investigation

    ERIC Educational Resources Information Center

    Nichols, Sue

    2011-01-01

    An ecological approach, emphasizing the importance of understanding multiple contexts for learning, underpins this study of libraries as activity spaces for young children's literacy participation. Five libraries serving a diversity of communities were the subject of ethnographic investigation incorporating participant observation, visual…

  19. Problematic Internet Use among Turkish University Students: A Multidimensional Investigation Based on Demographics and Internet Activities

    ERIC Educational Resources Information Center

    Tekinarslan, Erkan; Gurer, Melih Derya

    2011-01-01

    This study investigated the Turkish undergraduate university students' problematic Internet use (PIU) levels on different dimensions based on demographics (e.g., gender, Internet use by time of day), and Internet activities (e.g., chat, entertainment, social networking, information searching, etc.). Moreover, the study explored some predictors of…

  20. Investigating Learner Attitudes toward E-Books as Learning Tools: Based on the Activity Theory Approach

    ERIC Educational Resources Information Center

    Liaw, Shu-Sheng; Huang, Hsiu-Mei

    2016-01-01

    This paper investigates the use of e-books as learning tools in terms of learner satisfaction, usefulness, behavioral intention, and learning effectiveness. Based on the activity theory approach, this research develops a research model to understand learner attitudes toward e-books in two physical sizes: 10? and 7?. Results suggest that screen…

  1. Authentic Experience within Investigative Activities: The Role of Reflection in the Learning Environment.

    ERIC Educational Resources Information Center

    Petrosino, Anthony J., Jr.

    This document examines how a unit on model rockets, designed to be a "hands-on" activity within the "Mission to Mars" curriculum that was implemented in the Nashville (Tennessee) area middle schools, has been used to investigate children's understanding of experimentation. A literature review explores some of the traditional…

  2. Investigating Acceptance toward Mobile Learning to Assist Individual Knowledge Management: Based on Activity Theory Approach

    ERIC Educational Resources Information Center

    Liaw, Shu-Sheng; Hatala, Marek; Huang, Hsiu-Mei

    2010-01-01

    Mobile devices could facilitate human interaction and access to knowledge resources anytime and anywhere. With respect to wide application possibilities of mobile learning, investigating learners' acceptance towards it is an essential issue. Based on activity theory approach, this research explores positive factors for the acceptance of m-learning…

  3. The Investigation of the Relation between Physical Activity and Academic Success

    ERIC Educational Resources Information Center

    Iri, Ruchan; Ibis, Serkan; Aktug, Zait Burak

    2017-01-01

    The purpose of the study is to investigate the interaction among Physical Activity Levels (PAL), academic successes, perceived academic competency and Motor Skills (MS) of male and female students at the age of 14-17 in terms of gender variable. The PALs, perceived academic competency and academic successes were determined through International…

  4. Investigation of the Relations between Religious Activities and Subjective Well-Being of High School Students

    ERIC Educational Resources Information Center

    Eryilmaz, Ali

    2015-01-01

    This study aims to investigate the relation between participation in religious activities and the subjective wellbeing of high school students. The study group involves 196 participants, 99 female and 97 male; all of the participants were adolescents attending high school in Eskisehir, Turkey, their ages varying from 14 to 16. The measurement…

  5. An Investigation into Social Learning Activities by Practitioners in Open Educational Practices

    ERIC Educational Resources Information Center

    Schreurs, Bieke; Van den Beemt, Antoine; Prinsen, Fleur; Witthaus, Gabi; Conole, Gráinne; De Laat, Maarten

    2014-01-01

    By investigating how educational practitioners participate in activities around open educational practices (OEP), this paper aims at contributing to an understanding of open practices and how these practitioners learn to use OEP. Our research is guided by the following hypothesis: Different social configurations support a variety of social…

  6. Locating Active Plate Boundaries by Earthquake Data. Crustal Evaluation Education Project. Teacher's Guide [and] Student Investigation.

    ERIC Educational Resources Information Center

    Stoever, Edward C., Jr.

    Crustal Evolution Education Project (CEEP) modules were designed to: (1) provide students with the methods and results of continuing investigations into the composition, history, and processes of the earth's crust and the application of this knowledge to man's activities and (2) to be used by teachers with little or no previous background in the…

  7. Going Underground: A Field Investigation and Lab Activity on Karst Topography and Water Systems

    ERIC Educational Resources Information Center

    O'Dell, Gary; Gonzalez-Espada, Wilson

    2011-01-01

    Students learn science best with activities that mirror the way scientists work. This article describes how geologists investigate groundwater flow systems in areas of karst topography--geologic formations shaped by dissolving bedrock--and provides a way for students to replicate this research. Students also use electric current to model water…

  8. Investigating Pre-Service Early Childhood Teachers' Attitudes towards the Computer Based Education in Science Activities

    ERIC Educational Resources Information Center

    Yilmaz, Nursel; Alici, Sule

    2011-01-01

    The purpose of this study was to investigate pre-service early childhood teachers' attitudes towards using Computer Based Education (CBE) while implementing science activities. More specifically, the present study examined the effect of different variables such as gender, year in program, experience in preschool, owing a computer, and the…

  9. Evaluation of some biological tests as parameters for microbial activities in soils. II. Field investigations.

    PubMed

    Abd-El-Malek, Y; Monib, M; Rizk, S G; Shehata, S M

    1976-01-01

    Investigations were designed to study the effect of certain factors on the microbial activities in soil. The parameters, used as an index of the microbial activities, were total bacterial counts, dehydrogenase activity, oxidation of organic carbon, and CO2 evolved/7 days. Bahteem Farm clay soil was examined for determining the effects of depth, type of fertilization, and crop rotation on the microbial activities. It appears that the microbial activities, as indicated by the tested parameters, were more pronounced in the surface 15 cm-layer than in the subsurface layer (15-30 cm). Results of all the parameters tested showed markedly higher increases with farmyard manure than with nitrogenous fertilizer and in the control, without significant differences between the latter two. Moreover, the time of sampling had no effect on the results obtained for all parameters. Different types of rotations did not exert significant variation in total bacterial counts, though more than one crop per year increased the organic carbon content of soil and mostly the dehydrogenase activity, whereas the evolution of CO2 tended to decrease. At Gabal el-Asfar Farm, the effect of irrigation with sewage effluent, for long periods, on the microbial activities of sandy soil was investigated. Sewage water stimulated the total bacteria, raised the dehydrogenase activity, the organic carbon, and the production of CO2. In North El Tahreer and Mariut Sectors, the effect of both the type and age of cultivation on the microbial activities in the calcareous soils were examined. Cultivation raised the figures of all the tested parameters progressively with time of cultivation. It was also noticed that crops exerted more beneficial effects on microbial activities than orchards, and the dehydrogenase test was the most reliable parameter to reveal this fact.

  10. Investigation of spherical loudspeaker arrays for local active control of sound.

    PubMed

    Peleg, Tomer; Rafaely, Boaz

    2011-10-01

    Active control of sound can be employed globally to reduce noise levels in an entire enclosure, or locally around a listener's head. Recently, spherical loudspeaker arrays have been studied as multiple-channel sources for local active control of sound, presenting the fundamental theory and several active control configurations. In this paper, important aspects of using a spherical loudspeaker array for local active control of sound are further investigated. First, the feasibility of creating sphere-shaped quiet zones away from the source is studied both theoretically and numerically, showing that these quiet zones are associated with sound amplification and poor system robustness. To mitigate the latter, the design of shell-shaped quiet zones around the source is investigated. A combination of two spherical sources is then studied with the aim of enlarging the quiet zone. The two sources are employed to generate quiet zones that surround a rigid sphere, investigating the application of active control around a listener's head. A significant improvement in performance is demonstrated in this case over a conventional headrest-type system that uses two monopole secondary sources. Finally, several simulations are presented to support the theoretical work and to demonstrate the performance and limitations of the system.

  11. Ellagic acid derivatives from Syzygium cumini stem bark: investigation of their antiplasmodial activity.

    PubMed

    Simões-Pires, Claudia A; Vargas, Sandra; Marston, Andrew; Ioset, Jean-Robert; Paulo, Marçal Q; Matheeussen, An; Maes, Louis

    2009-10-01

    Bioguided fractionation of Syzygium cumini (Myrtaceae) bark decoction for antiplasmodial activity was performed, leading to the isolation of three known ellagic acid derivatives (ellagic acid, ellagic acid 4-O-alpha-L-2"-acetylrhamnopyranoside, 3-O-methylellagic acid 3'-O-alpha-L-rhamnopyranoside), as well as the new derivative 3-O-methylellagic acid 3'-O-beta-D-glucopyranoside. Activity investigation was based on the reduction of P. falciparum (PfK1) parasitaemia in vitro and the inhibition of beta-hematin formation, a known mechanism of action of some antimalarial drugs. Among the investigated ellagic acid derivatives, only ellagic acid was able to reduce P. falciparum parasitaemia in vitro and inhibit beta-hematin formation, suggesting that free hydroxyl groups are necessary for activity within this class of compounds.

  12. Increased Variation in Adh Enzyme Activity in Drosophila Mutation-Accumulation Experiment Is Not Due to Transposable Elements at the Adh Structural Gene

    PubMed Central

    Aquadro, C. F.; Tachida, H.; Langley, C. H.; Harada, K.; Mukai, T.

    1990-01-01

    We present here a molecular analysis of the region surrounding the structural gene encoding alcohol dehydrogenase (Adh) in 47 lines of Drosophila melanogaster that have each accumulated mutations for 300 generations. While these lines show a significant increase in variation of alcohol dehydrogenase enzyme activity compared to control lines, we found no restriction map variation in a 13-kb region including the complete Adh structural gene and roughly 5 kb of both 5' and 3' sequences. Thus, the rapid accumulation of ADH activity variation after 28,200 allele generations does not appear to have been due to the mobilization of transposable elements into or out of the Adh structural gene region. PMID:1963870

  13. Investigation of photodynamic activity of water-soluble porphyrins in vitro and in vivo

    NASA Astrophysics Data System (ADS)

    Gyulkhandanyan, Grigor V.; Ghambaryan, Sona S.; Amelyan, Gayane V.; Ghazaryan, Robert K.; Arsenyan, Flora H.; Gyulkhandanyan, Aram G.

    2006-02-01

    Photodynamic therapy (PDT) is the method of photosensitized tumor treatment. It is based on the photosensitizer (PS) selective accumulation in tumors, its subsequent activation under the light influence and oxygen active form formation that results in tumor destruction. Photodynamic action of some new water-soluble porphyrins was investigated in our laboratory. Dose-dependent effect of these porphyrins was shown on PC-12 murine pheochromocytoma cell line. The results revealed that the efficiency of the investigated porphyrins decreased in the following way: TOEPyP (meso-tetra-(4-N-oxyethylpyridyl)porphyrin) > Zn-TOEPyP > Ag-TOEPyP. It was shown that TOEPyP possessed nearly the same photodynamic activity (LD50) as well-known photosensitizer chlorin e6. These porphyrins have also demonstrated quite high photodynamic activity in vivo. The results were obtained in the experiments on white mice with engrafted C-180 (Croker's sarcoma). Antitumor activity of these porphyrins in the dark was 30-40%, whereas photodynamic activity was 45-60%.

  14. Task Failure during Exercise to Exhaustion in Normoxia and Hypoxia Is Due to Reduced Muscle Activation Caused by Central Mechanisms While Muscle Metaboreflex Does Not Limit Performance

    PubMed Central

    Torres-Peralta, Rafael; Morales-Alamo, David; González-Izal, Miriam; Losa-Reyna, José; Pérez-Suárez, Ismael; Izquierdo, Mikel; Calbet, José A. L.

    2016-01-01

    To determine whether task failure during incremental exercise to exhaustion (IE) is principally due to reduced neural drive and increased metaboreflex activation eleven men (22 ± 2 years) performed a 10 s control isokinetic sprint (IS; 80 rpm) after a short warm-up. This was immediately followed by an IE in normoxia (Nx, PIO2:143 mmHg) and hypoxia (Hyp, PIO2:73 mmHg) in random order, separated by a 120 min resting period. At exhaustion, the circulation of both legs was occluded instantaneously (300 mmHg) during 10 or 60 s to impede recovery and increase metaboreflex activation. This was immediately followed by an IS with open circulation. Electromyographic recordings were obtained from the vastus medialis and lateralis. Muscle biopsies and blood gases were obtained in separate experiments. During the last 10 s of the IE, pulmonary ventilation, VO2, power output and muscle activation were lower in hypoxia than in normoxia, while pedaling rate was similar. Compared to the control sprint, performance (IS-Wpeak) was reduced to a greater extent after the IE-Nx (11% lower P < 0.05) than IE-Hyp. The root mean square (EMGRMS) was reduced by 38 and 27% during IS performed after IE-Nx and IE-Hyp, respectively (Nx vs. Hyp: P < 0.05). Post-ischemia IS-EMGRMS values were higher than during the last 10 s of IE. Sprint exercise mean (IS-MPF) and median (IS-MdPF) power frequencies, and burst duration, were more reduced after IE-Nx than IE-Hyp (P < 0.05). Despite increased muscle lactate accumulation, acidification, and metaboreflex activation from 10 to 60 s of ischemia, IS-Wmean (+23%) and burst duration (+10%) increased, while IS-EMGRMS decreased (−24%, P < 0.05), with IS-MPF and IS-MdPF remaining unchanged. In conclusion, close to task failure, muscle activation is lower in hypoxia than in normoxia. Task failure is predominantly caused by central mechanisms, which recover to great extent within 1 min even when the legs remain ischemic. There is dissociation between the

  15. An actinomycete isolate from solitary wasp mud nest having strong antibacterial activity and kills the Candida cells due to the shrinkage and the cytosolic loss

    PubMed Central

    Kumar, Vijay; Naik, Bindu; Gusain, Omprakash; Bisht, Gajraj S.

    2014-01-01

    An actinomycetes strain designated as MN 2(6) was isolated from the solitary wasp mud nest. The isolate was identified using polyphasic taxonomy. It produced the extensive branched brown substrate and white aerial hyphae that changed into grayish black. The aerial mycelia produced the spiral spore chains with rugose spore surface. The growth was observed between temperature range of 27–37°C, pH 8–10 and below salt concentration of 6% (w/v). The comparative analysis of 16S rRNA gene sequence and phylogenetic relationship showed that strain MN 2(6) lies in clade with Streptomyces hygroscopicus subsp. hygroscopicus NRRL 2387T, Streptomyces sporocinereus NBRC 100766T and Streptomyces demainii NRRL B-1478T with which it shares a 16S rRNA gene sequence similarity of 99.3%. The strain MN 2(6) can be differentiated from type strains based on phenotypic characteristics. The strain MN 2(6) showed most promising activity against Gram-positive, Gram-negative bacteria, acid-fast bacilli and Candida species suggesting broad-spectrum characteristics of the active metabolite. Evaluation of anti-candidal activity of the metabolite of strain MN 2(6) by scanning electron microscopy (SEM) revealed changed external morphology of yeast. It kills the Candida cells due to the shrinkage and the cytosolic loss. However, further studies are required to elucidate the structure of the active metabolite produced by the isolate MN 2(6). PMID:25191320

  16. The bacterial Entner-Doudoroff pathway does not replace glycolysis in Saccharomyces cerevisiae due to the lack of activity of iron-sulfur cluster enzyme 6-phosphogluconate dehydratase.

    PubMed

    Benisch, Feline; Boles, Eckhard

    2014-02-10

    Replacement of the glycolytic pathway of Saccharomyces cerevisiae by a bacterial Entner-Doudoroff pathway (EDP) would result in lower ATP production and therefore a lower biomass yield is expected that would further allow higher products yields in the fermentation of sugars. To establish catabolism of glucose via the EDP in S. cerevisiae requires expression of only two additional enzyme activities, 6-phosphogluconate dehydratase (PGDH) and KDPG aldolase. In this work, KDPG aldolase from Escherichia coli could be successfully expressed in the yeast cytosol with very high enzyme activity. Nevertheless, simultaneous expression of KDPG aldolase and a codon optimized PGDH gene of E. coli could not replace glycolysis or the pentose phosphate pathway in growth experiments. It could be shown that this was due to the very low enzyme activity of PGDH. This bacterial enzyme is a [4Fe-4S] iron-sulfur cluster protein. Several attempts to improve the availability of iron-sulfur clusters or iron in the yeast cells, to attract the iron-sulfur cluster assembly machinery to Leu1-PGDH fusion proteins or to localize the PGDH in the mitochondria did not result in improved enzyme activities. From our results we conclude that establishing functional expression of iron-sulfur cluster enzymes will be a major task for the integration of the EDP and other biochemical pathways in yeast.

  17. Investigation of antiaromatase activity using hepatic microsomes of Nile tilapia (Oreochromis niloticus).

    PubMed

    Sassa-Deepaeng, Tanongsak; Chaisri, Wasana; Pikulkaew, Surachai; Okonogi, Siriporn

    2017-03-19

    Microsomal aromatase enzymes of humans and rats have been used in antiaromatase assays, but enzyme activity is species-specific. The current study extracted hepatic microsomes of Nile tilapia (Oreochromis niloticus) to investigate and compare the antiaromatase activity of chrysin, quercetin, and quercitrin. This activity was evaluated using a dibenzylfluorescein (DBF) assay. Results revealed that the age and body weight of Nile tilapia affected the yield of extracted microsomes. Extraction of hepatic microsomes of Nile tilapia was most effective when using a reaction medium with a pH of 8.0. A DBF assay using Nile tilapia microsomes revealed significant differences in levels of antiaromatase activity for chrysin, quercetin, and quercitrin. Chrysin was the most potent aromatase inhibitor, with an IC50 of 0.25 mg/mL. In addition, chrysin is an aromatase inhibitor that also inhibits the proliferation of cancer cells. Hepatic microsomes of Nile tilapia can be used to investigate and compare the antiaromatase activity of different compounds.

  18. An Investigation into Cloud Condensation Nuclei (CCN) Activation in the Southwestern United States

    NASA Astrophysics Data System (ADS)

    Crosbie, E. C.; Youn, J.; Wonaschuetz, A.; Sorooshian, A.

    2013-12-01

    Cloud condensation nuclei (CCN) comprise a key component of the total aerosol with critical influences on weather and climate. The importance of CCN concentration is often linked to radiative feedbacks associated with cloud albedo, which has important consequences for climate sensitivity, however the importance of CCN may also extend to cloud dynamics in convective environments and atmospheric electricity. We present data from fifteen months of field measurements taken in an urban environment on a rooftop of a building at the University of Arizona campus in Tucson, Arizona. CCN were measured at high temporal resolution concurrently with measurements of particle size distributions, meteorological parameters, and the composition of the organic fraction of the aerosol. We investigate monthly, weekly, and diurnal patterns in the data along with activation ratio and apparent activation diameter, which provide important insight into the micro-scale dependencies of cloud activation. Furthermore, we examine the relationship between CCN and local and regional meteorology, with particular focus on the North American Monsoon season, to investigate feedback and response mechanisms relating to dynamics, microphysics, and chemistry. Monsoon aerosol are shown to have favorable composition to allow for higher CCN activity and thus lower apparent activation diameters. This finding coincides with enhanced aqueous-phase chemistry to produce more hygroscopic aerosol constituents such as sulfate and water-soluble organic compounds.

  19. Genome-wide investigation of schizophrenia associated plasma Ndel1 enzyme activity.

    PubMed

    Gadelha, Ary; Coleman, Jonathan; Breen, Gerome; Mazzoti, Diego Robles; Yonamine, Camila M; Pellegrino, Renata; Ota, Vanessa Kiyomi; Belangero, Sintia Iole; Glessner, Joseph; Sleiman, Patrick; Hakonarson, Hakon; Hayashi, Mirian A F; Bressan, Rodrigo A

    2016-04-01

    Ndel1 is a DISC1-interacting oligopeptidase that cleaves in vitro neuropeptides as neurotensin and bradykinin, and which has been associated with both neuronal migration and neurite outgrowth. We previously reported that plasma Ndel1 enzyme activity is lower in patients with schizophrenia (SCZ) compared to healthy controls (HCs). To our knowledge, no previous study has investigated the genetic factors associated with the plasma Ndel1 enzyme activity. In the current analyses, samples from 83 SCZ patients and 92 control subjects that were assayed for plasma Ndel1 enzyme activity were genotyped on Illumina Omni Express arrays. A genetic relationship matrix using genome-wide information was then used for ancestry correction, and association statistics were calculated genome-wide. Ndel1 enzyme activity was significantly lower in patients with SCZ (t=4.9; p<0.001) and was found to be associated with CAMK1D, MAGI2, CCDC25, and GABGR3, at a level of suggestive significance (p<10(-6)), independent of the clinical status. Then, we performed a model to investigate the observed differences for case/control measures. 2 SNPs at region 1p22.2 reached the p<10(-7) level. ZFPM2 and MAD1L1 were the only two genes with more than one hit at 10(-6) order of p value. Therefore, Ndel1 enzyme activity is a complex trait influenced by many different genetic variants that may contribute to SCZ physiopathology.

  20. Investigation of platelet aggregation inhibitory activity by phenyl amides and esters of piperidinecarboxylic acids.

    PubMed

    de Candia, Modesto; Summo, Luciana; Carrieri, Antonio; Altomare, Cosimo; Nardecchia, Adele; Cellamare, Saverio; Carotti, Angelo

    2003-04-03

    A series of anilides and phenyl esters of piperidine-3-carboxylic acid (nipecotic acid) were synthesized and tested for the ability to inhibit aggregation of human platelet rich-plasma triggered by adenosine 5'-diphosphate (ADP) and adrenaline. As a rule, amides were about two times more active than the corresponding esters, and derivatives bearing substituents at the para position of the phenyl ring were significantly more active than the meta-substituted ones. Among the tested compounds, 4-hexyloxyanilide of nipecotic acid (18a) was found to be the most active one, its IC(50) value being close to that of the most active bis-3-carbamoylpiperidines reported in literature (ca. 40 micro M) and aspirin (ca. 60 microM) in ADP- and adrenaline-induced aggregation, respectively. Compared with the isomeric 4-hexyloxyanilides of piperidine-2-carboxylic (pipecolinic) and piperidine-4-carboxylic (isonipecotic) acids, compound 18a showed higher activity, and a Hansch-type quantitative structure-activity relationship (QSAR) study highlighted lipophilicity and increase in electron density of the phenyl ring as the properties which mainly increase the antiplatelet activity (r(2)=0.74, q(2)=0.64). The interaction of nipecotoyl anilides with phosphatidylinositol, a major component of the inner layer of the platelet membranes, was investigated by means of flexible docking calculation methods to give an account of a key event underlying their biological action.

  1. Physical activity and lung cancer risk in the European Prospective Investigation into Cancer and Nutrition Cohort.

    PubMed

    Steindorf, Karen; Friedenreich, Christine; Linseisen, Jakob; Rohrmann, Sabine; Rundle, Andrew; Veglia, Fabrizio; Vineis, Paolo; Johnsen, Nina Fønns; Tjønneland, Anne; Overvad, Kim; Raaschou-Nielsen, Ole; Clavel-Chapelon, Françoise; Boutron-Ruault, Marie-Christine; Schulz, Mandy; Boeing, Heiner; Trichopoulou, Antonia; Kalapothaki, Victoria; Koliva, Maria; Krogh, Vittorio; Palli, Domenico; Tumino, Rosario; Panico, Salvatore; Monninkhof, Evelyn; Peeters, Petra H; Boshuizen, Hendriek C; Bueno-de-Mesquita, H Bas; Chirlaque, Maria-Dolores; Agudo, Antonio; Larrañaga, Nerea; Quirós, José R; Martínez, Carmen; Barricarte, Aurelio; Janzon, Lars; Berglund, Göran; Bingham, Sheila; Khaw, Kay-Tee; Key, Timothy J; Norat, Teresa; Jenab, Mazda; Cust, Anne; Riboli, Elio

    2006-11-15

    Research conducted predominantly in male populations on physical activity and lung cancer has yielded inconsistent results. We examined this relationship among 416,277 men and women from the European Prospective Investigation into Cancer and Nutrition (EPIC). Detailed information on recent recreational, household and occupational physical activity, smoking habits and diet was assessed at baseline between 1992 and 2000. Relative risks (RR) were estimated using Cox regression. During 6.3 years of follow-up we identified 607 men and 476 women with incident lung cancer. We did not observe an inverse association between recent occupational, recreational or household physical activity and lung cancer risk in either males or females. However, we found some reduction in lung cancer risk associated with sports in males (adjusted RR = 0.71; 95% confidence interval 0.50-0.98; highest tertile vs. inactive group), cycling (RR = 0.73; 0.54-0.99) in females and non-occupational vigorous physical activity. For occupational physical activity, lung cancer risk was increased for unemployed men (adjusted RR = 1.57; 1.20-2.05) and men with standing occupations (RR = 1.35; 1.02-1.79) compared with sitting professions. There was no evidence of heterogeneity of physical activity associations across countries, or across any of the considered cofactors. For some histologic subtypes suggestive sex-specific reductions, limited by subgroup sizes, were observed, especially with vigorous physical activity. In total, our study shows no consistent protective associations of physical activity with lung cancer risk. It can be assumed that the elevated risks found for occupational physical activity are not produced mechanistically by physical activity itself but rather reflect exposure to occupation-related lung cancer risk factors.

  2. Cardiosphere-derived cells from pediatric end-stage heart failure patients have enhanced functional activity due to the heat shock response regulating the secretome.

    PubMed

    Sharma, Sudhish; Mishra, Rachana; Simpson, David; Wehman, Brody; Colletti, Evan J; Deshmukh, Savitha; Datla, Srinivasa Raju; Balachandran, Keerti; Guo, Yin; Chen, Ling; Siddiqui, Osama T; Kaushal, Shalesh; Kaushal, Sunjay

    2015-04-01

    We have demonstrated that human neonatal cardiosphere-derived cells (CDCs) derived from the young are more regenerative due to their robust secretome. However, it is unclear how the decompensated pediatric heart impacts the functional activity of their CDCs. Our aim was to characterize the potency of pediatric CDCs derived from normal functioning myocardium of control heart disease (CHD) patients to those generated from age-matched end stage heart failure (ESHF) patients and to determine the mechanisms involved. ESHF-derived CDCs contained a higher number of c-kit(+) , Islet-1(+) , and Sca-1(+) cells. When transplanted into an infarcted rodent model, ESHF-derived CDCs significantly demonstrated higher restoration of ventricular function, prevented adverse remodeling, and enhanced angiogenesis when compared with CHD patients. The superior functional recovery of the ESHF-derived CDCs was mediated in part by increased SDF-1α and VEGF-A secretion resulting in augmented recruitment of endogenous stem cells and proliferation of cardiomyocytes. We determined the mechanism is due to the secretome directed by the heat shock response (HSR), which is supported by three lines of evidence. First, gain of function studies demonstrated that increased HSR induced the lower functioning CHD-derived CDCs to significantly restore myocardial function. Second, loss-of function studies targeting the HSR impaired the ability of the ESHF-derived CDCs to functionally recover the injured myocardium. Finally, the native ESHF myocardium had an increased number of c-kit(+) cardiac stem cells. These findings suggest that the HSR enhances the functional activity of ESHF-derived CDCs by increasing their secretome activity, notably SDF-1α and VEGF-A.

  3. Phytochemical investigation of sesquiterpenes from the fruits of Schisandra chinensis and their cytotoxic activity.

    PubMed

    Venkanna, A; Siva, B; Poornima, B; Vadaparthi, P R Rao; Prasad, K Rajendra; Reddy, K Ashok; Reddy, G Bhanu Prakash; Babu, K Suresh

    2014-06-01

    Phytochemical investigation of ethanolic extract from the fruits of Schisandra chinensis led to the isolation of four new sesquiterpenes (1-4); their structures were determined by a combination of NMR (1D and 2D) and MS spectroscopic techniques. In addition, all these isolates were screened for their cytotoxic activities against MCF-7, Caco-2, Hela, Lncap, Hep G2 and MDA-MB231 cancer cell lines. Results indicated that compounds 2 and 3 displayed potent cytotoxic activity against Caco2 cell lines with IC50 values of 17.10 μg/mM and 16.46 μg/mM, respectively.

  4. Numerical investigation of oscillatory multiphase flow in porous medium with chemically active skeleton

    NASA Astrophysics Data System (ADS)

    Konyukhov, A. V.; Zavialov, I. N.

    2016-11-01

    Self-oscillating mode of reaction front propagation in multiphase flow in the porous medium with chemically active skeleton is investigated numerically. The considered flow represents an immiscible displacement process, such that the displacing fluid and the skeleton of the porous medium have chemically active components which react with production of gaseous phase. The calculations have demonstrated strong influence of the reaction kinetics on stability of the reactive flow. The presence of a time delay between the change of concentration of the reactants and the change of the reaction rate is shown to stimulate transition of the reaction front propagation to the oscillatory mode.

  5. Barbiturate bearing aroylhydrazine derivatives: Synthesis, NMR investigations, single crystal X-ray studies and biological activity

    NASA Astrophysics Data System (ADS)

    Giziroglu, Emrah; Sarikurkcu, Cengiz; Aygün, Muhittin; Basbulbul, Gamze; Soyleyici, H. Can; Firinci, Erkan; Kirkan, Bulent; Alkis, Ayse; Saylica, Tayfur; Biyik, Halil

    2016-03-01

    A series of barbituric acid aroylhydrazine derivatives have been prepared from their corresponding 1,3-dimethyl-5-acetyl barbituric acid and aroylhydrazines. All compounds have been fully characterized by using FT-IR, multinuclear NMR (1H, 13C) and Mass (MS) spectrometry. We also describe the X-ray crystal structure of 3a, which crystallizes in the monoclinic P21/n space group. The crystal structure is stabilized with infinite linear chains of dimeric units. Furthermore, all compounds were investigated for their tyrosinase inhibition, antioxidative and antimicrobial activies. The results from biological activity assays have shown that all of compounds have excellent antioxidant, significant tyrosinase inhibition and moderate antimicrobial activity.

  6. An Investigation of the Largest Flares in Active Cool Star Binaries with ALEXIS

    NASA Technical Reports Server (NTRS)

    Stern, Robert A.

    1998-01-01

    After a long delay due to the initial problems with the ALEXIS attitude control, the heroic efforts on the part of the ALEXIS satellite team enabled us to carry out this survey. However, the combination of the higher than expected and variable background in the ALEXIS detectors, and the lower throughput of the ALEXIS telescopes resulted in no convincing detections of large flares from the active binary systems. In addition, vignetting-corrected effective exposure times from the ALEXIS aspect solution were not available prior to the end of this contract; therefore, we were unable to convert upper limits measured in ALEXIS counts to the equivalent.

  7. An investigation of the mimetic enzyme activity of two-dimensional Pd-based nanostructures

    NASA Astrophysics Data System (ADS)

    Wei, Jingping; Chen, Xiaolan; Shi, Saige; Mo, Shiguang; Zheng, Nanfeng

    2015-11-01

    In this work, we investigated the mimetic enzyme activity of two-dimensional (2D) Pd-based nanostructures (e.g. Pd nanosheets, Pd@Au and Pd@Pt nanoplates) and found that they possess intrinsic peroxidase-, oxidase- and catalase-like activities. These nanostructures were able to activate hydrogen peroxide or dissolved oxygen for catalyzing the oxidation of organic substrates, and decompose hydrogen peroxide to generate oxygen. More systematic investigations revealed that the peroxidase-like activities of these Pd-based nanomaterials were highly structure- and composition-dependent. Among them, Pd@Pt nanoplates displayed the highest peroxidase-like activity. Based on these findings, Pd-based nanostructures were applied for the colorimetric detection of H2O2 and glucose, and also the electro-catalytic reduction of H2O2. This work offers a promising prospect for the application of 2D noble metal nanostructures in biocatalysis.In this work, we investigated the mimetic enzyme activity of two-dimensional (2D) Pd-based nanostructures (e.g. Pd nanosheets, Pd@Au and Pd@Pt nanoplates) and found that they possess intrinsic peroxidase-, oxidase- and catalase-like activities. These nanostructures were able to activate hydrogen peroxide or dissolved oxygen for catalyzing the oxidation of organic substrates, and decompose hydrogen peroxide to generate oxygen. More systematic investigations revealed that the peroxidase-like activities of these Pd-based nanomaterials were highly structure- and composition-dependent. Among them, Pd@Pt nanoplates displayed the highest peroxidase-like activity. Based on these findings, Pd-based nanostructures were applied for the colorimetric detection of H2O2 and glucose, and also the electro-catalytic reduction of H2O2. This work offers a promising prospect for the application of 2D noble metal nanostructures in biocatalysis. Electronic supplementary information (ESI) available: TEM images, EDX and dispersion stability of Pd-based nanomaterials

  8. Investigation of osteogenic activity of primary rabbit periosteal cells stimulated by multi-axial tensile strain.

    PubMed

    Chiu, Chih-Hao; Liu, Jun-Liang; Chang, Chih-Hsuan; Lei, Kin Fong; Chen, Alvin Chao-Yu

    2017-03-01

    Periosteum-derived cells was indicated to respond to mechanical force and have stem cell potential capable of differentiating into multiple tissue. Investigation of osteogenic activity under mechanical stimulation is important to understand the therapeutic conditions of fracture healing. In this work, a cell culture platform was developed for respectively providing isotropic and anisotropic axial strain. Primary rabbit periosteal cells were isolated and cultured in the chamber. Multi-axial tensile strain was received and osteogenic activity was investigated by mRNA expressions of CBFA1 and OPN. The highest mRNA expression was found in moderate strain (5-8%) under anisotropic axial strain. These results provided important foundation for further in vivo studies and development of tailor-made stretching rehabilitation equipment.

  9. Experimental investigation of different active noise control concepts applied to a passenger car equipped with an active windshield

    NASA Astrophysics Data System (ADS)

    Misol, M.; Algermissen, S.; Monner, H. P.

    2012-05-01

    The main purpose of this work is the implementation and experimental investigation of different active structural acoustic control (ASAC) concepts for the reduction of interior noise in an automobile passenger compartment. For the control experiments, a medium-class test car was used, which had been equipped with an active windshield. The active windshield consists of the serial-production laminated glass pane augmented with piezoceramic patch-transducers applied to the blackened rim of the windshield. A multi-reference test provided measurement data for the identification of a local discrete-time state-space model (SSM). The subsequent acquisition of frequency response functions (FRF) by way of using the same actuators but measuring on a much finer grid provided the database for the formulation of a least-squares problem to derive a global system model. Based on the local and global discrete-time SSMs, different controllers were designed and experimentally realized. The comparison of the vibration levels in open- and closed-loop showed a global reduction of 5-7 dB in the acoustically relevant frequency band containing the second and third structural resonance of the windshield system. The occurrence of complex operational deflection shapes (ODS) was identified as the main limitation concerning the disturbance rejection of the active system. The acoustic performance of the ASAC system is reflected in a reduction up to 15 dB in sound pressure level (SPL).

  10. Mice with increased angiogenesis and osteogenesis due to conditional activation of HIF pathway in osteoblasts are protected from ovariectomy induced bone loss.

    PubMed

    Zhao, Qiang; Shen, Xing; Zhang, Wei; Zhu, Guochun; Qi, Jin; Deng, Lianfu

    2012-03-01

    Postmenopausal osteoporosis is characterized by a reduction in the numbers of sinusoidal and arterial capillaries in the bone marrow and reduced bone perfusion suggesting a role of vascular component in the pathogenesis of osteoporosis. Previous studies have shown that bone formation and angiogenesis are positively coupled through activation of the hypoxia inducible factor (HIF1α) signaling pathway. Therefore, we hypothesized that mice with increased angiogenesis and osteogenesis due to activation of the HIF signaling pathway in osteoblasts, via osteoblast specific disruption of HIF degrading protein von Hippel-Lindau (VHL) (ΔVhl), are protected from ovariectomy induced bone loss. ΔVhl mice and control littermates were ovariectomized or sham operated and four weeks later bone quality was evaluated along with blood vessel formation. Trabecular and cortical bone volume was strikingly increased in ΔVhl mice along with blood vessel formation as compared to control littermates. In control mice, ovariectomy significantly decreased bone mineral density, deteriorated bone microarchitecture, and decreased mechanical strength compared to the sham operated control mice. This was accompanied with a significant decrease in blood vessel volume and expressions of HIF1α, HIF2α, and VEGF proteins at the distal femur in ovariectomized control mice. In contrast, ovariectomy in ΔVhl mice had absolutely no effect on either the blood vessel formation or the bone structural and mechanical quality parameters. These data indicate that activation of HIF signaling pathway in osteoblasts may prevent estrogen deficiency-induced bone loss and decrease in blood vessels in bone marrow.

  11. Catalog of Completed Studies, US Army Health Care Studies and Clinical Investigation Activity.

    DTIC Science & Technology

    1984-12-10

    Environment Substudy: AD A139001 Effects of Chemical Protective Clothing on the Performance of Basic Medical Tasks (HCSD Report #83-001) 8 DATE TITLE...Contact urticaria to parabens , Arch. Dermatol, 1979, 115:1231-1232. *13 Smith, E. B., Padilla, R. S., McCabe, J. M., Becker, L. E., Benzoyl...Chemical Environment . --3-Report #83-001. Ft. Sam Houston, TX: Health Care Studies and Clinical Investigation Activity, December 1982. 19 Penetar, D. M

  12. Investigation of the atmospheric particulates deposited on leaves using instrumental neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Cercasov, V.

    A method for the separation of surface contamination on plant leaves by plastic film stripping was applied. The particulate matter embedded in the film was analysed by neutron activation. The investigation was directed especially towards the determination of the trace element content of the suitable plastic matrices and of the influence of solvents. The practicability of this method is demonstrated by analysing films stripped from plant leaves with different degrees of pollution.

  13. Investigating active faulting in the south-central Chilean forearc by local seismicity and moment tensor inversions

    NASA Astrophysics Data System (ADS)

    Rietbrock, A.; Bohm, M.; Echtler, H.; Melnick, D.; Bruhn, C.; Bataille, K.

    2004-12-01

    The seismological ISSA experiment is giving a detailed insight into the seismicity distribution of southern Chile, where major earthquakes (M>8) have repeatedly ruptured the surface, involving vertical offsets of several meters. During a nearly 5-month observation period in 1999 and 2000 a temporary seismic network recorded approximately 350 local earthquakes. Two localized areas, North and South of the Arauco peninsula, showed a very high seismic activity in and above the interplate seismic zone of the Nazca-South America convergent margin. We used a double-difference relocation technique to obtain detailed images of the seismicity distribution in these areas. We also determined fault plane solutions to interpret the observed alignment of earthquakes hypocenters. Due to the low signal to noise ratio reliable first motion reading were difficult to achieve, which only very few clear readings. To overcome this problem we used moment tensor inversions to estimate reliable source mechanisms. However, for small magnitude earthquakes (<5) the biggest obstacle is the alignment of synthetic and observed waveforms. Inverting only for the amplitude spectrum, and therefore dropping the information in the phase spectrum can mostly circumvent the alignment problem. The two clusters investigated show high waveform correlation coefficients for most of the earthquakes indicating that possibly changes in fluid pressure can be responsible for triggering the events. After relocation most of the hypocenters in each of the two clusters align on a eastward dipping fault. Source mechanisms obtained indicate thrust faulting, where one of the possible fault planes aligns with the steep eastward dipping fault based on the seismicity distribution. These faults are reaching down to the top of the seismogenic zone and may serve as pathways for ascending fluids released in the subduction process. Active crustal-scale faulting below and active uplift of the coast account for active tectonic

  14. Investigations of the synergistic enhancement of antimicrobial activity in mixtures of magainin 2 and PGLa.

    PubMed

    Glattard, Elise; Salnikov, Evgeniy S; Aisenbrey, Christopher; Bechinger, Burkhard

    2016-03-01

    Magainins are antimicrobial peptides isolated from the African clawed frog Xenopus laevis. They interact with bacterial membranes where they cause channel formation and membrane disruption. When added as a cocktail magainin 2 and PGLa are considerably more efficient when compared to the corresponding amounts of individual components. In order to investigate this synergistic interaction of PGLa and magainin a number of magainin variants have been prepared and investigated in biological and biophysical assays. In particular we report on the antimicrobial activities and solid-state NMR investigations of magainins that have been extended by a carboxyterminal GGC tripeptide to form covalently linked dimers. Notably, when the formation of the covalent linkage is prevented by exchanging the cystein by serine or alanine no loss in efficiency was observed indicating that the covalent interaction is not necessary for synergistic interaction. In a next step peptides labelled with (15)N and (2)H were reconstituted into oriented membranes and their topology studied by solid-state NMR spectroscopy. The tendency of some of these peptides to adopt membrane-spanning alignments does not correlate with their synergistic activities in antimicrobial assays. In contrast, the stable alignment of PGLa parallel to the surface of membranes made of Escherichia coli lipid extracts is strongly suggestive that the peptides develop synergistic activities when in an in-planar configuration. Notably, the phospholipid head groups of these samples show a high degree of disturbance suggesting that the synergistic interactions between the magainin peptides could be mediated through the lipid phase.

  15. An investigation of antioxidant and anti-inflammatory activities from blood components of Crocodile (Crocodylus siamensis).

    PubMed

    Phosri, Santi; Mahakunakorn, Pramote; Lueangsakulthai, Jiraporn; Jangpromma, Nisachon; Swatsitang, Prasan; Daduang, Sakda; Dhiravisit, Apisak; Thammasirirak, Sompong

    2014-10-01

    Antioxidant and anti-inflammatory activities were found from Crocodylus siamensis (C. siamensis) blood. The 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, nitric oxide scavenging, hydroxyl radical scavenging and linoleic peroxidation assays were used to investigate the antioxidant activities of the crocodile blood. Results show that crocodile blood components had antioxidant activity, especially hemoglobin (40.58 % nitric oxide radical inhibition), crude leukocyte extract (78 % linoleic peroxidation inhibition) and plasma (57.27 % hydroxyl radical inhibition). Additionally, the anti-inflammatory activity of the crocodile blood was studied using murine macrophage (RAW 264.7) as a model. The results show that hemoglobin, crude leukocyte extract and plasma were not toxic to RAW 264.7 cells. Also they showed anti-inflammatory activity by reduced nitric oxide (NO) and interleukin 6 (IL-6) productions from lipopolysaccharide (LPS)-stimulated cells. The NO inhibition percentages of hemoglobin, crude leukocyte extract and plasma were 31.9, 48.24 and 44.27 %, respectively. However, only crude leukocyte extract could inhibit IL-6 production. So, the results of this research directly indicate that hemoglobin, crude leukocyte extract and plasma of C. siamensis blood provide both antioxidant and anti-inflammatory activities, which could be used as a supplementary agent in pharmaceutical products.

  16. Experimental and molecular mechanics and ab initio investigation of activated adsorption and desorption of trichloroethylene in mineral micropores.

    PubMed

    Farrell, James; Luo, Jing; Blowers, Paul; Curry, Joan

    2002-04-01

    This research investigated activated adsorption of a hydrophobic organic contaminant(HOC) in mineral micropores using experimental and molecular modeling techniques. Adsorption of trichloroethylene (TCE) on a silica gel adsorbent was measured using a frontal analysis chromatography technique at atmospheric and elevated fluid pressures. Increasing the fluid pressure yielded increased TCE uptake that was not released upon lowering the pressure back to atmospheric conditions. This showed that the increase in pressure was able to rapidly induce the formation of a desorption-resistant fraction that previous investigations have shown requires months to develop at atmospheric pressure. Grand Canonical Monte Carlo (GCMC) modeling was then used to elucidate the nature of water and TCE behavior within silica micropores. The GCMC modeling showed that molecular scale packing restrictions resulted in pore fluid densities that ranged from 0.28 to 0.78 of those in the bulk solution. The modeling also showed that TCE was able to displace water from hydrophilic mineral pores due to molecular scale packing restrictions. Exothermic isosteric heats for TCE adsorption up to -27 kJ/mol were observed and were greatest in pores of 7 and 8 A. This indicated that TCE adsorption was energetically most favorable in pores that were minimally large enough to accommodate a TCE molecule. The pressure-induced uptake appeared to result primarily from an increase in the packing density in the smallest pores. Ab initio calculations showed that small distortions of a TCE molecule from its low energy conformation require high activation energies. Results from this study indicate that activated adsorption requiring bond angle distortions in the adsorbate may be responsible forthe slow attainment of adsorptive equilibrium of HOCs on microporous solids. Likewise, activated desorption from molecular-sized adsorption sites may contribute to the slow release of HOCs from aquifer sediments.

  17. Synthesis and investigation of the specific activity of the DNA-doxorubicin conjugates

    NASA Astrophysics Data System (ADS)

    Kokorev, A. V.; Zaborovskiy, A. V.; Kotlyarov, A. A.; Balykova, L. A.; Malkina, M. A.; Kargina, I. V.; Gromova, E. V.; Medvezhonkov, V. Yu; Gurevich, K. G.; Shchukin, S. A.; Pyataev, N. A.

    2017-01-01

    In the present work, the method of obtaining the conjugate of the anticancer chemotherapeutic agent doxorubicin to the exogenous double-stranded DNA of the sturgeons is proposed (the source: commercial drug “Derinat”). The optimal conditions for synthesis of conjugate (pH, temperature and the mass ratio of the components), ensuring the highest degree of binding the chemotherapeutic agent to a carrier, were picked out. Clearing the conjugate from the non-encapsulated chemotherapeutic agent was being made by ultrafiltration method. The investigation of the toxicity and specific antineoplastic activity of the synthesized complex was conducted. The performance of the drug toxicity were established on the intact mice in compliance with the accepted standards. The antineoplastic activity was evaluated upon the Tumor Growth Inhibition Index and Metastasis Inhibition Index on mice with the transplanted Lewis lung carcinoma (LLC). It was demonstrated that the conjugate toxicity is approximately lower that the one of the unconjugated doxorubicin (LD 50 was equal 14.6 mg/kg and 9.9 mg/kg for the conjugate and doxorubicin, respectively). The specific antineoplastic activity was investigated in equitoxic doses of the drug. It was established that the conjugate being administered in equitoxic doses possesses a stronger antineoplastic activity, than the water-soluble drug (maximum 35% more as to the tumor volume and 51% more as to the Tumor Growth Inhibition index).

  18. Investigation of the immunosuppressive activity of Physalin H on T lymphocytes.

    PubMed

    Yu, Youjun; Sun, Lijuan; Ma, Lei; Li, Jiyu; Hu, Lihong; Liu, Jianwen

    2010-03-01

    Physalis angulata is an annual herb widely used in folk medicine. It is mainly used for treating rheumatoid arthritis (RA). Following bioactivity-guided isolation, a representative immunosuppressive compound, Physalin H was been identified from this herb medicine. The purpose of this work was to assess the immunosuppressive activity of Physalin H on T cells and to explore its potential mode of action. The results showed that Physalin H in a dose-dependent manner significantly inhibited the proliferation of T cells induced by concanavalin A (ConA) and by the mixed lymphocyte culture reaction (MLR). This inhibitive activity was mainly due to interfering DNA replication in G1 stages. In vivo experiments showed that, administration of Physalin H dose-dependently suppressed CD4(+) T cell mediated delayed-type hypersensitivity (DTH) reactions, and suppressed antigen-specific T-cell response in ovalbumin (OVA) immunized mice. Further study indicated that Physalin H could modulate Th1/Th2 cytokine balance and induce the production of immune regulation target Heme oxygenase (HO)-1 in T-cells in vitro. In this study, we demonstrated the immunosuppressive effect of Physalin H on T cells both in vitro and in vivo, and the immunosuppressive activity might be attributed to the suppression of T cell activation and proliferation, the modulation of Th1/Th2 cytokine balance and the induction of HO-1 in T cells.

  19. Groundwater Contamination Due to Activities of an Intensive Hog Farming Operation Located on a Geologic Fault in East Mediterranean: A Study on COD, BOD₅ and Microbial Load.

    PubMed

    Michalopoulos, Charalampos; Tzamtzis, Nikolaos; Liodakis, Stylianos

    2016-02-01

    The application of treated animal wastewater produced in intensive fog farming operations (IHFOs) on surface soil, leads to groundwater contamination. In this study, the contamination of a Mediterranean aquifer caused by long-term application of treated wastewater, produced by an IHFO, on a plot with a geologic fault within the IHFO boundaries, was investigated. Groundwater samples were taken from monitoring wells close to the IHFO. A significant increase of chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total viable count (TVC) and total coliform (TC) concentrations was found in wells, compared to control monitoring well, which were mainly affected by the subsurface flow of contaminated water, due to the presence of the geologic fault. During the winter, significant increases in concentrations of COD, BOD5, TVC and TC were noted and attributed to increased precipitation, which assisted in the accelerated transport of organic compounds and microbial load, through geologic fault, to groundwater.

  20. Osteopetrorickets due to Snx10 Deficiency in Mice Results from Both Failed Osteoclast Activity and Loss of Gastric Acid-Dependent Calcium Absorption

    PubMed Central

    Ye, Liang; Morse, Leslie R.; Zhang, Li; Sasaki, Hajime; Mills, Jason C.; Odgren, Paul R.; Sibbel, Greg; Stanley, James R. L.; Wong, Gee; Zamarioli, Ariane; Battaglino, Ricardo A.

    2015-01-01

    Mutations in sorting nexin 10 (Snx10) have recently been found to account for roughly 4% of all human malignant osteopetrosis, some of them fatal. To study the disease pathogenesis, we investigated the expression of Snx10 and created mouse models in which Snx10 was knocked down globally or knocked out in osteoclasts. Endocytosis is severely defective in Snx10-deficent osteoclasts, as is extracellular acidification, ruffled border formation, and bone resorption. We also discovered that Snx10 is highly expressed in stomach epithelium, with mutations leading to high stomach pH and low calcium solubilization. Global Snx10-deficiency in mice results in a combined phenotype: osteopetrosis (due to osteoclast defect) and rickets (due to high stomach pH and low calcium availability, resulting in impaired bone mineralization). Osteopetrorickets, the paradoxical association of insufficient mineralization in the context of a positive total body calcium balance, is thought to occur due to the inability of the osteoclasts to maintain normal calcium–phosphorus homeostasis. However, osteoclast-specific Snx10 knockout had no effect on calcium balance, and therefore led to severe osteopetrosis without rickets. Moreover, supplementation with calcium gluconate rescued mice from the rachitic phenotype and dramatically extended life span in global Snx10-deficient mice, suggesting that this may be a life-saving component of the clinical approach to Snx10-dependent human osteopetrosis that has previously gone unrecognized. We conclude that tissue-specific effects of Snx10 mutation need to be considered in clinical approaches to this disease entity. Reliance solely on hematopoietic stem cell transplantation can leave hypocalcemia uncorrected with sometimes fatal consequences. These studies established an essential role for Snx10 in bone homeostasis and underscore the importance of gastric acidification in calcium uptake. PMID:25811986

  1. Effects Due to the Structure and Materials of a Charge Stripping Foil on Activation of the RCS Injection Segment of J-PARC

    NASA Astrophysics Data System (ADS)

    Kato, Shuichi; Yamazaki, Yoshio; Yoshimoto, Masahiro; Kinsho, Michikazu; Sasao, Mamiko; Kenmotsu, Takahiro; Wada, Motoi

    Because of their robustness, Hybrid type thick Boron-doped Carbon (HBC) stripping foils are used in the 3 GeV Rapid Cycling Synchrotron (RCS) of Japan-Proton Accelerator Research Complex (J-PARC). The foil and the supporting structure are irradiated by H- beams. The activation of the surrounding structures and that of the foil itself is the problem to be solved. The ACAT (Atomic Collision in Amorphous Target) code has been modified to calculate the angle straggling of the transmission beam by multiple collisions in the foil. The results did not show any substantial deterioration of the beam optics due to the foil. The gamma spectra measured during a shutdown period of the RCS has been analyzed to see the correlation with the beam transport in the system.

  2. Kinetic and thermodynamic investigation on ascorbate oxidase activity and stability of a Cucurbita maxima extract.

    PubMed

    Porto, Tatiana S; Porto, Camila S; Cavalcanti, Maria T H; Filho, José L Lima; Perego, Patrizia; Porto, Ana L F; Converti, Attilio; Pessoa, Adalberto

    2006-01-01

    The kinetic and thermodynamic properties of ascorbate oxidase (AO) activity and stability of a Cucurbita maxima extract were investigated. Activity tests performed at 25 degrees C using initial ascorbic acid concentration in the range 50-750 M allowed estimating the Michaelis constant for this substrate (Km = 126 microM) and the maximum initial rate of ascorbic acid oxidation (A0,max = 1.57 mM min-1). The main thermodynamic parameters of the enzyme reaction (DeltaH* = 10.3 kJ mol-1; DeltaG* = 87.2 kJ mol-1; DeltaS* = -258 J mol-1 K-1) were estimated through activity tests performed at 25-48 C. Within such a temperature range, no decrease in the initial reaction rate was detected. The long-term thermostability of the raw extract was then investigated by means of residual activity tests carried out at 10-70 degrees C, which allowed estimating the thermodynamic parameters of the irreversible enzyme inactivation as well (DeltaH*D = 51.7 kJ mol-1; DeltaG*D = 103 kJ mol-1; S*D = -160 J mol-1 K-1). Taking into account the specific rate of AO inactivation determined at different temperatures, we also estimated the enzyme half-life (1047 min at 10 degrees C and 21.2 min at 70 degrees C) and predicted the integral activity of a continuous system using this enzyme preparation. This work should be considered as a preliminary attempt to characterize the AO activity of a C. maxima extract before its concentration by liquid-liquid extraction techniques.

  3. Investigation of effects of terpene skin penetration enhancers on stability and biological activity of lysozyme.

    PubMed

    Varman, Rahul M; Singh, Somnath

    2012-12-01

    The transport of proteins through skin can be facilitated potentially by using terpenes as chemical enhancers. However, we do not know about the effects of these enhancers on the stability and biological activity of proteins which is crucial for the development of safe and efficient formulations. Therefore, this project investigated the effects of terpene-based skin penetration enhancers which are reported as nontoxic to the skin (e.g., limonene, p-cymene, geraniol, farnesol, eugenol, menthol, terpineol, carveol, carvone, fenchone, and verbenone), on the conformational stability and biological activity of a model protein lysozyme. Terpene (5% v/v) was added to lysozyme solution and kept for 24 h (the time normally a transdermal patch remains) for investigating conformational stability profiles and biological activity. Fourier transform infrared spectrophotometer was used to analyze different secondary structures, e.g., α-helix, β-sheet, β-turn, and random coil. Conformational changes were also monitored by differential scanning calorimeter by determining midpoint transition temperature (Tm) and calorimetric enthalpy (ΔH). Biological activity of lysozyme was determined by measuring decrease in A (450) when it was added to a suspension of Micrococcus lysodeikticus. The results of this study indicate that terpenes 9, 10, and 11 (carvone, L-fenchone, and L-verbenone) decreased conformational stability and biological activity of lysozyme significantly (p < 0.05) less than other terpenes used in this study. It is concluded that smaller terpenes containing ketones with low lipophilicity (log K (ow) ∼2.00) would be optimal for preserving conformational stability and biological activity of lysozyme in a transdermal formulation containing terpene as permeation enhancer.

  4. Anti-Osteoclastic Activity of Artemisia capillaris Thunb. Extract Depends upon Attenuation of Osteoclast Differentiation and Bone Resorption-Associated Acidification Due to Chlorogenic Acid, Hyperoside, and Scoparone

    PubMed Central

    Lee, Sang-Hyun; Lee, Jung-Yun; Kwon, Young-In; Jang, Hae-Dong

    2017-01-01

    The present study attempts to elucidate the anti-osteoporotic activity of Artemisia capillaris Thunb. in the form of anti-osteoclastic effect and responsible bioactive compounds. The contents of chlorogenic acid, caffeic acid, hyperoside, isoquercitrin, isochlorogenic acid A, and scoparone in Artemisia capillaris hydroethanolic extract (ACHE) were 38.53, 0.52, 4.07, 3.03, 13.90, and 6.59 mg/g, respectively. ACHE diminished osteoclast differentiation and bone resorption due to chlorogenic acid, hyperoside, and scoparone. In addition, ACHE attenuated acidification as well as reducing tumor necrosis factor receptor-associated factor 6 (TRAF6) expression and its association with vacuolar H+-adenosine triphosphatase (V-ATPase). Furthermore, chlorogenic acid, hyperoside, and scoparone from A. capillaris abrogated the association of V-ATPase with TRAF6, suggesting that the blockage of bone resorption by A. capillaris was partially mediated by reducing acidification through down-regulating interaction of V-ATPase with TRAF6 due to scoparone as well as chlorogenic acid and hyperoside. These results imply that the anti-osteoclastic effect of A. capillaris through down-regulating osteoclast differentiation and bone resorption may contribute to its anti-osteoporotic effect. PMID:28165389

  5. The antifungal activity of sulfonylated/carboxylated derivatives of dibenzo-1,4-dioxine-2-acetyloxime may be due to inhibition of lanosterol-14alpha-demethylase.

    PubMed

    Mastrolorenzo, A; Scozzafava, A; Supuran, C T

    2000-01-01

    Aryl/alkyl-sulfonyl-, aryl/alkylcarboxyl- and aryl(sulfonyl)carbamyl/thiocarbamyl-derivatives of dibenzo-1,4-dioxine-2-acetyloxime were prepared by reaction of the title compound with sulfonyl halides, sulfonic acid anhydrides, acyl chlorides/carboxylic acids, arylsulfonyl isocyanates, aryl/acyl isocyanates or isothiocyanates. Several of the newly synthesized compounds showed effective in vitro antifungal activity against Aspergillus and Candida spp., some of them showing activities comparable to ketoconazole (with minimum inhibitory concentrations in the range of 1.2-4 microg/mL) against the two Aspergillus strains, but possessing a lower activity as compared to ketoconazole against C. albicans. Of the three investigated strains, best activity was detected against A. flavus. The mechanism of action of these compounds probably involves inhibition of ergosterol biosynthesis by interaction with lanosterol-14-alpha-demethylase (CYP51A1), since reduced amounts of ergosterol were found by means of HPLC, in cultures of the sensitive strain A. flavus treated with some of these inhibitors. Thus, the compounds reported here might possess a similar mechanism of action at molecular level with that of the widely used azole antifungals.

  6. Investigation of gender- and age-related preferences of men and women regarding lighting conditions for activation and relaxation

    NASA Astrophysics Data System (ADS)

    Schweitzer, S.; Schinagl, C.; Djuras, G.; Frühwirth, M.; Hoschopf, H.; Wagner, F.; Schulz, B.; Nemitz, W.; Grote, V.; Reidl, S.; Pritz, P.; Moser, M.; Wenzl, F. P.

    2016-09-01

    In recent years, LED lighting became an indispensable alternative to conventional lighting systems. Sophisticated solutions offer not only comfortable white light with a good color rendering. They also provide the possibility of changing illuminance and color temperature. Some systems even simulate daylight over the entire day, some including natural variations as due to clouds. Such systems are supposed to support the chronobiological needs of human and to have a positive effect on well-being, performance, sleep-quality and health. Lighting can also be used to support specific aims in a situation, like to improve productivity in activation or to support recreation in relaxation. Research regarding suitable light-settings for such situations and superordinate questions like their influence on well-being and health is still incomplete. We investigated the subjective preferences of men and women regarding light-settings for activation and relaxation. We supplied two rooms and four cubes with light sources that provide the possibility of tuning illuminance, color temperature and deviation from Plackian locus. More than 80 individuals - belonging to four groups differing in gender and age - were asked to imagine activating and recovering situations for which they should adjust suitable and pleasant lighting by tuning the above mentioned light properties. It was shown that there are clear differences in the lighting conditions preferred for these two situations. Also some combined gender- and age-specific differences became apparent.

  7. Biphasic investigation of contact mechanics in natural human hips during activities.

    PubMed

    Li, Junyan; Hua, Xijin; Jin, Zhongmin; Fisher, John; Wilcox, Ruth K

    2014-06-01

    The aim of this study was to determine the cartilage contact mechanics and the associated fluid pressurisation of the hip joint under eight daily activities, using a three-dimensional finite element hip model with biphasic cartilage layers and generic geometries. Loads with spatial and temporal variations were applied over time and the time-dependent performance of the hip cartilage during walking was also evaluated. It was found that the fluid support ratio was over 90% during the majority of the cycles for all the eight activities. A reduced fluid support ratio was observed for the time at which the contact region slid towards the interior edge of the acetabular cartilage, but these occurred when the absolute level of the peak contact stress was minimal. Over 10 cycles of gait, the peak contact stress and peak fluid pressure remained constant, but a faster process of fluid exudation was observed for the interior edge region of the acetabular cartilage. The results demonstrate the excellent function of the hip cartilage within which the solid matrix is prevented from high levels of stress during activities owing to the load shared by fluid pressurisation. The findings are important in gaining a better understanding of the hip function during daily activities, as well as the pathology of hip degeneration and potential for future interventions. They provide a basis for future subject-specific biphasic investigations of hip performance during activities.

  8. Synthesis of Mono-PEGylated Growth Hormone Releasing Peptide-2 and Investigation of its Biological Activity.

    PubMed

    Hu, Xiaoyu; Xu, Beihua; Zhou, Ziniu

    2015-10-01

    The purpose of this study was to investigate an efficient synthetic route to the mono-PEGylated growth hormone releasing peptide-2 (GHRP-2) and its biological activity in vivo. The commercially available key PEGylating reagent, mPEG-NHS ester, was successfully utilized to the synthesis of mono-PEGylated GHRP-2, during which the PEGylation profiles of GHRP-2 were monitored by high-performance liquid chromatography (HPLC). The product was purified by cation exchange chromatography, and its biological activity was conducted in rats. The desired mono-PEGylated GHRP-2 as the major product was readily obtained in anhydrous aprotic solvent, such as dimethyl formamide (DMF) and dimethylsulfoxide (DMSO), when the molar ratio of mPEG-NHS ester to GHRP-2 was fixed to be 0.8:1. The products were characterized by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. The evaluation of the biological activity for the products showed that the mono-PEGylated GHRP-2 gave a more stable activity than GHRP-2, suggesting that PEGylation led to the increase in the half-life of GHRP-2 in plasma without greatly impairing the biological activity. PEGylation of the GHRP-2 is a good choice for the development of the GHRP-2 applications.

  9. Investigating Primary Marine Aerosol Properties: CCN Activity of Sea Salt and Mixed Inorganic–Organic Particles

    PubMed Central

    2012-01-01

    Sea spray particles ejected as a result of bubbles bursting from artificial seawater containing salt and organic matter in a stainless steel tank were sampled for size distribution, morphology, and cloud condensation nucleus (CCN) activity. Bubbles were generated either by aeration through a diffuser or by water jet impingement on the seawater surface. Three objectives were addressed in this study. First, CCN activities of NaCl and two types of artificial sea salt containing only inorganic components were measured to establish a baseline for further measurements of mixed organic–inorganic particles. Second, the effect of varying bubble residence time in the bulk seawater solution on particle size and CCN activity was investigated and was found to be insignificant for the organic compounds studied. Finally, CCN activities of particles produced from jet impingement were compared with those produced from diffuser aeration. Analyses indicate a considerable amount of organic enrichment in the jet-produced particles relative to the bulk seawater composition when sodium laurate, an organic surfactant, is present in the seawater. In this case, the production of a thick foam layer during impingement may explain the difference in activation and supports hypotheses that particle production from the two methods of generating bubbles is not equal. PMID:22809370

  10. Physiological investigation of automobile driver's activation index using simulated monotonous driving.

    PubMed

    Yamakoshi, T; Yamakoshi, K; Tanaka, S; Nogawa, M; Kusakabe, M; Kusumi, M; Tanida, K

    2004-01-01

    Monotonous automobile operation in our daily life may cause the lowering of what might be termed an activation state of the human body, resulting in an increased risk of an accident. We therefore propose to create a more suitable environment in-car so as to allow active operation of the vehicle, hopefully thus avoiding potentially dangerous situations during driving. In order to develop such an activation method as a final goal, we have firstly focused on the acquisition of physiological variables, including cardiovascular parameters, during presentation to the driver of a monotonous screen image, simulating autonomous travel of constant-speed on a motorway. Subsequently, we investigated the derivation of a driver's activation index. During the screen image presentation, a momentary electrical stimulation of about 1 second duration was involuntarily applied to a subject's shoulder to obtain a physiological response. We have successfully monitored various physiological variables during the image presentation, and results suggest that a peculiar pattern in the beat-by-beat change of blood pressure in response to the involuntary stimulus may be an appropriate, and feasible, index relevant to activation state.

  11. Activation of Natural Killer Cells in Patients with Chronic Bone and Joint Infection due to Staphylococci Expressing or Not the Small Colony Variant Phenotype

    PubMed Central

    Viel, Sébastien; Rouzaire, Paul; Laurent, Frédéric; Walzer, Thierry; Bienvenu, Jacques; Valour, Florent; Chidiac, Christian; Ferry, Tristan; Group, The Lyon BJI Study

    2014-01-01

    Chronic bone and joint infections (BJI) are devastating diseases. Relapses are frequently observed, as some pathogens, especially staphylococci, can persist intracellularly by expressing a particular phenotype called small colony variant (SCV). As natural killer (NK) cells are lymphocytes specialized in the killing of host cells infected by intracellular pathogens, we studied NK cells of patients with chronic BJI due to staphylococci expressing or not SCVs (10 patients in both groups). Controls were patients infected with other bacteria without detectable expression of SCVs, and healthy volunteers. NK cell phenotype was evaluated from PBMCs by flow cytometry. Degranulation capacity was evaluated after stimulation with K562 cells in vitro. We found that NK cells were activated in terms of CD69 expression, loss of CD16 and perforin, in all infected patients in comparison with healthy volunteers, independently of the SCV phenotype. Peripheral NK cells in patients with chronic BJI display signs of recent activation and degranulation in vivo in response to CD16-mediated signals, regardless of the type of bacteria involved. This could involve a universal capacity of isolates responsible for chronic BJI to produce undetectable SCVs in vivo, which might be a target of future intervention. PMID:26464851

  12. Comparative investigation of antioxidant activity of human serum blood by amperometric, voltammetric and chemiluminescent methods

    PubMed Central

    Korotkova, Elena; Voronova, Olesya; Sazhina, Natalia; Petrova, Ekatherina; Artamonov, Anton; Chernyavskaya, Ludmila; Dorozhko, Elena

    2015-01-01

    Introduction A blood test can provide important information about the functional state of the antioxidant system. Malfunction of this system increases the concentration of free radicals and can cause oxidative stress. A difficulty in assessing oxidative stress is the lack of a universal method for determining the antioxidant activity (AOA) of blood components, because of their different nature. Material and methods The objects of investigation were sera of 30 male patients with a diagnosis of alcohol dependence syndrome and healthy donors. Comparative investigation of total antioxidant activity (TAA) of human serum blood was carried out by voltammetric (VA), amperometric (AM) and chemiluminescent (HL) methods. Results All applied methods revealed that serum TAA of the patients with alcoholism is lower than TAA of healthy donors (control group); according to amperometric method the average value of serum TAA was 850 ±210 nA × s, and 660 ±150 nA × s for healthy donors and alcoholics respectively (p < 0.05). Similar trend was revealed by chemiluminescence and voltammetry methods. The results confirm that thiol compounds make a significant contribution to the antioxidant activity of serum. The average thiol concentrations were 0.94 ±0.34 mmol/l and 1.21 ±0.36 mmol/l (p < 0.05) for alcoholics and healthy donors respectively. Decreasing thiol concentration in blood of alcoholics leads to depletion of antioxidant systems of blood. However, the differences between the results of AM, VA and HL methods were significant, because they reflected different aspects of antioxidant activity. Conclusions For objective assessment of antioxidant activity of biological objects, we suggest using methods based on different model systems. PMID:27695499

  13. Theoretical investigation of the activity of cobalt oxides for the electrochemical oxidation of water.

    PubMed

    Bajdich, Michal; García-Mota, Mónica; Vojvodic, Aleksandra; Nørskov, Jens K; Bell, Alexis T

    2013-09-11

    The presence of layered cobalt oxides has been identified experimentally in Co-based anodes under oxygen-evolving conditions. In this work, we report the results of theoretical investigations of the relative stability of layered and spinel bulk phases of Co oxides, as well as the stability of selected surfaces as a function of applied potential and pH. We then study the oxygen evolution reaction (OER) on these surfaces and obtain activity trends at experimentally relevant electro-chemical conditions. Our calculated volume Pourbaix diagram shows that β-CoOOH is the active phase where the OER occurs in alkaline media. We calculate relative surface stabilities and adsorbate coverages of the most stable low-index surfaces of β-CoOOH: (0001), (0112), and (1014). We find that at low applied potentials, the (1014) surface is the most stable, while the (0112) surface is the more stable at higher potentials. Next, we compare the theoretical overpotentials for all three surfaces and find that the (1014) surface is the most active one as characterized by an overpotential of η = 0.48 V. The high activity of the (1014) surface can be attributed to the observation that the resting state of Co in the active site is Co(3+) during the OER, whereas Co is in the Co(4+) state in the less active surfaces. Lastly, we demonstrate that the overpotential of the (1014) surface can be lowered further by surface substitution of Co by Ni. This finding could explain the experimentally observed enhancement in the OER activity of Ni(y)Co(1-y)O(x) thin films with increasing Ni content. All energetics in this work were obtained from density functional theory using the Hubbard-U correction.

  14. Investigating Biofilm Production, Coagulase and Hemolytic Activity in Candida Species Isolated From Denture Stomatitis Patients

    PubMed Central

    Yigit, Nimet; Aktas, Esin; Dagistan, Saadettin; Ayyildiz, Ahmet

    2011-01-01

    Objective: Oral candidiasis, in the form of Candida-associated denture stomatitis, represents a common disease in a large percentage of denture wearers, and Candida albicans remains the most commonly isolated species. In this study, we aimed to evaluate biofilm production, coagulase and hemolytic activity of Candida species isolated from denture stomatitis patients. Materials and Methods: This study included 70 patients (31 female, 39 male). Forty-eight of the patients were found to have a positive culture. A total of 48 Candida isolates representing five species, C. albicans (n=17), C. glabrata (n=10), C. krusei (n=9), C. kefyr (n=7) and C. parapsilosis (n=5), were tested. Their coagulase activities were evaluated by a classical tube coagulase test with rabbit plasma. A blood plate assay on 3% enriched sheep blood Sabouraud-dextrose agar (SDA) was used to determine their in vitro hemolytic activities. Biofilm production was determined by a visual tube method. Results: Twenty-one Candida isolates exhibited coagulase activity, and the coagulase activities of the C. albicans (64.7%) isolates were higher than other species. C. albicans, C. glabrata, C. kefyr and C. krusei species demonstrated beta hemolysis. C. parapsilosis strains failed to demonstrate any hemolytic activities. Fifteen (88.0%) of the C. albicans strains were biofilm positive. Six (35.2%) of these strains were strongly positive, 8 (47.0%) C. albicans strains were moderately positive and 1 (5.8%) C. albicans strain was weakly positive. Sixteen (51.6%) of the non-albicans Candida strains were biofilm positive while 15 (48.3%) did not produce biofilms. Conclusion: The results of this present study indicate coagulase, hemolytic activity and biofilm production by Candida spp. isolated from patients with denture stomatitis. Investigations of these virulence factors might be helpful in gaining information about the possible virulence of oral Candida species related to denture stomatitis. PMID:25610156

  15. An investigation into the relationship between age and physiological function in highly active older adults

    PubMed Central

    Pollock, Ross D; Carter, Scott; Velloso, Cristiana P; Duggal, Niharika A; Lord, Janet M; Lazarus, Norman R; Harridge, Stephen D R

    2015-01-01

    Despite extensive research, the relationship between age and physiological function remains poorly characterised and there are currently no reliable markers of human ageing. This is probably due to a number of confounding factors, particularly in studies of a cross-sectional nature. These include inter-subject genetic variation, as well as inter-generational differences in nutrition, healthcare and insufficient levels of physical activity as well as other environmental factors. We have studied a cohort of highly and homogeneously active older male (n = 84) and female (n = 41) cyclists aged 55–79 years who it is proposed represent a model for the study of human ageing free from the majority of confounding factors, especially inactivity. The aim of the study was to identify physiological markers of ageing by assessing the relationship between function and age across a wide range of indices. Each participant underwent a detailed physiological profiling which included measures of cardiovascular, respiratory, neuromuscular, metabolic, endocrine and cognitive functions, bone strength, and health and well-being. Significant associations between age and function were observed for many functions. The maximal rate of oxygen consumption ( showed the closest association with age (r = −0.443 to −0.664; P < 0.001), but even here the variance in age for any given level was high, precluding the clear identification of the age of any individual. The results of this cross-sectional study suggest that even when many confounding variables are removed the relationship between function and healthy ageing is complex and likely to be highly individualistic and that physical activity levels must be taken into account in ageing studies. Key Points The relationship between age and physiological function remains poorly defined and there are no physiological markers that can be used to reliably predict the age of an individual. This could be due to a variety of confounding

  16. Investigating Microbial Activity in Diazotrophic Methane Seep Sediment via Transcript Analysis and Single-Cell FISH-NanoSIMS

    NASA Astrophysics Data System (ADS)

    Dekas, A. E.; Connon, S. A.; Chadwick, G.; Orphan, V. J.

    2012-12-01

    pattern of transcripts recovered in the mesocosm experiments. This analysis revealed 15N enrichment in free-living (i.e. non-ANME associated) members of the Desulfobulbaceae in 15N2 incubations with methane, while free-living Desulfosarcina/Desulfococcus cells, as well as nearly 40 unidentified DAPI-stained cells, were not 15N enriched. However, further NanoSIMS analyses of DSB in a variety of incubation conditions suggests that this enrichment may be due to N sharing between the ANME and DSB while in tight physical association, and then subsequent dissociation, rather than nitrogen fixation by the DSB. If true, this is an excellent example of the potential pitfalls of single cell stable isotope labeling experiments, and potential false positives due to the recycling of labeled material between (even transiently) closely associated symbionts. This work highlights both the utility of transcript analysis as a hypothesis-generator for direct analyses of microbial activity via stable isotope labeling, as well as the need to contextualize labeling experiments with investigations of microbial community structure.

  17. Active investigation of material damage under load using micro-CT

    SciTech Connect

    Navalgund, Megha Mishra, Debasish; Manoharan, V.; Zunjarrao, Suraj

    2015-03-31

    Due the growth of composite materials across multiple industries such as Aviation, Wind there is an increasing need to not just standardize and improve manufacturing processes but also to design these materials for the specific applications. One of the things that this translates to is understanding how failure initiates and grows in these materials and at what loads, especially around internal flaws such as voids or features such as ply drops. Traditional methods of investigating internal damage such as CT lack the resolution to resolve ply level damage in composites. Interrupted testing with layer removal can be used to investigate internal damage using microscopy; however this is a destructive method. Advanced techniques such as such as DIC are useful for in-situ damage detection, however are limited to surface information and would not enable interrogating the volume. Computed tomography has become a state of the art technique for metrology and complete volumetric investigation especially for metallic components. However, its application to the composite world is still nascent. This paper demonstrates micro-CT’s capability as a gauge to quantitatively estimate the extent of damage and understand the propagation of damage in PMC composites while the component is under stress.

  18. Active investigation of material damage under load using micro-CT

    NASA Astrophysics Data System (ADS)

    Navalgund, Megha; Zunjarrao, Suraj; Mishra, Debasish; Manoharan, V.

    2015-03-01

    Due the growth of composite materials across multiple industries such as Aviation, Wind there is an increasing need to not just standardize and improve manufacturing processes but also to design these materials for the specific applications. One of the things that this translates to is understanding how failure initiates and grows in these materials and at what loads, especially around internal flaws such as voids or features such as ply drops. Traditional methods of investigating internal damage such as CT lack the resolution to resolve ply level damage in composites. Interrupted testing with layer removal can be used to investigate internal damage using microscopy; however this is a destructive method. Advanced techniques such as such as DIC are useful for in-situ damage detection, however are limited to surface information and would not enable interrogating the volume. Computed tomography has become a state of the art technique for metrology and complete volumetric investigation especially for metallic components. However, its application to the composite world is still nascent. This paper demonstrates micro-CT's capability as a gauge to quantitatively estimate the extent of damage & understand the propagation of damage in PMC composites while the component is under stress.

  19. EEG and FMRI coregistration to investigate the cortical oscillatory activities during finger movement.

    PubMed

    Formaggio, Emanuela; Storti, Silvia Francesca; Avesani, Mirko; Cerini, Roberto; Milanese, Franco; Gasparini, Anna; Acler, Michele; Pozzi Mucelli, Roberto; Fiaschi, Antonio; Manganotti, Paolo

    2008-12-01

    Electroencephalography combined with functional magnetic resonance imaging (EEG-fMRI) may be used to identify blood oxygenation level dependent (BOLD) signal changes associated with physiological and pathological EEG event. In this study we used EEG-fMRI to determine the possible correlation between topographical movement-related EEG changes in brain oscillatory activity recorded from EEG electrodes over the scalp and fMRI-BOLD cortical responses in motor areas during finger movement. Thirty-two channels of EEG were recorded in 9 subjects during eyes-open condition inside a 1.5 T magnetic resonance (MR) scanner using a MR-compatible EEG recording system. Off-line MRI artifact subtraction software was applied to obtain continuous EEG data during fMRI acquisition. For EEG data analysis we used the event-related-synchronization/desynchronization (ERS/ERD) approach to investigate where movement-related decreases in alpha and beta power are located. For image statistical analysis we used a general linear model (GLM) approach. There was a significant correlation between the positive-negative ratio of BOLD signal peaks and ERD values in the electrodes over the region of activation. We conclude that combined EEG-fMRI may be used to investigate movement-related oscillations of the human brain inside an MRI scanner and the movement-related changes in the EMG or EEG signals are useful to identify the brain activation sources responsible for BOLD-signal changes.

  20. Investigation of cream and ointment on antimicrobial activity of Mangifera indica extract.

    PubMed

    Awad El-Gied, Amgad A; Abdelkareem, Abdelkareem M; Hamedelniel, Elnazeer I

    2015-01-01

    Medicinal plants have curative properties due to the presence of various complex chemical substance of different composition, which are found as secondary plant metabolites in one or more parts of these plants. Mangifera indica Linn (MI L.) is a species of mango in the Anacardiaceae family. Phytoconstituents in the seed extracts may be responsible for the antimicrobial activity of the plant. The purpose of the study was to formulate and evaluate the antimicrobial herbal ointment and cream from extracts of the seeds of mango (MI L.) The formulated ointments containing oleaginous-based showed the best formulation compared to the emulsion water in oil type, the ointment and cream bases in different concentration 1%, 5% and 10%. The formulated ointment and cream of MI L. were subjected to evaluation of Uniformity of Weight, measurement of pH, viscosity, Spreadability, Acute skin irritation study, stability study and antimicrobial activity. Our study shows that MI has high potential as an antimicrobial agent when formulated as ointment and creams for topical use. Thus, the present study concludes that the formulated formulations of the MI are safe and efficient carriers, with potent antimicrobial activity.

  1. Investigation of cream and ointment on antimicrobial activity of Mangifera indica extract

    PubMed Central

    Awad El-Gied, Amgad A.; Abdelkareem, Abdelkareem M.; Hamedelniel, Elnazeer I.

    2015-01-01

    Medicinal plants have curative properties due to the presence of various complex chemical substance of different composition, which are found as secondary plant metabolites in one or more parts of these plants. Mangifera indica Linn (MI L.) is a species of mango in the Anacardiaceae family. Phytoconstituents in the seed extracts may be responsible for the antimicrobial activity of the plant. The purpose of the study was to formulate and evaluate the antimicrobial herbal ointment and cream from extracts of the seeds of mango (MI L.) The formulated ointments containing oleaginous-based showed the best formulation compared to the emulsion water in oil type, the ointment and cream bases in different concentration 1%, 5% and 10%. The formulated ointment and cream of MI L. were subjected to evaluation of Uniformity of Weight, measurement of pH, viscosity, Spreadability, Acute skin irritation study, stability study and antimicrobial activity. Our study shows that MI has high potential as an antimicrobial agent when formulated as ointment and creams for topical use. Thus, the present study concludes that the formulated formulations of the MI are safe and efficient carriers, with potent antimicrobial activity. PMID:25878974

  2. Wii, Kinect, and Move. Heart Rate, Oxygen Consumption, Energy Expenditure, and Ventilation due to Different Physically Active Video Game Systems in College Students.

    PubMed

    Scheer, Krista S; Siebrant, Sarah M; Brown, Gregory A; Shaw, Brandon S; Shaw, Ina

    Nintendo Wii, Sony Playstation Move, and Microsoft XBOX Kinect are home video gaming systems that involve player movement to control on-screen game play. Numerous investigations have demonstrated that playing Wii is moderate physical activity at best, but Move and Kinect have not been as thoroughly investigated. The purpose of this study was to compare heart rate, oxygen consumption, and ventilation while playing the games Wii Boxing, Kinect Boxing, and Move Gladiatorial Combat. Heart rate, oxygen consumption, and ventilation were measured at rest and during a graded exercise test in 10 males and 9 females (19.8 ± 0.33 y, 175.4 ± 2.0 cm, 80.2 ± 7.7 kg,). On another day, in a randomized order, the participants played Wii Boxing, Kinect Boxing, and Move Gladiatorial Combat while heart rate, ventilation, and oxygen consumption were measured. There were no differences in heart rate (116.0 ± 18.3 vs. 119.3 ± 17.6 vs. 120.1 ± 17.6 beats/min), oxygen consumption (9.2 ± 3.0 vs. 10.6 ± 2.4 vs. 9.6 ± 2.4 ml/kg/min), or minute ventilation (18.9 ± 5.7 vs. 20.8 ± 8.0 vs. 19.7 ± 6.4 L/min) when playing Wii boxing, Kinect boxing, or Move Gladiatorial Combat (respectively). Playing Nintendo Wii Boxing, XBOX Kinect Boxing, and Sony PlayStation Move Gladiatorial Combat all increase heart rate, oxygen consumption, and ventilation above resting levels but there were no significant differences between gaming systems. Overall, playing a "physically active" home video game system does not meet the minimal threshold for moderate intensity physical activity, regardless of gaming system.

  3. Ionosperic anomaly due to seismic activities - Part 1: Calibration of the VLF signal of VTX 18.2 KHz station from Kolkata and deviation during seismic events

    NASA Astrophysics Data System (ADS)

    Sasmal, S.; Chakrabarti, S. K.

    2009-08-01

    VLF signals are long thought to give away important information about the lithosphere-ionosphere coupling. In order to establish co-relations, if any, between the ionospheric activities and the earthquakes, we need to understand what the reference signals are, throughout the year. The best opportunity to do this is during the period of solar minimum where the number of flares and sunspots are negligible and the data would be primarily affected by the sun and variation would be due to normal sunset and sunrise effects. In this paper, we present the result of the sunrise and sunset terminators as a function of the day of the year for a period of four years, viz, 2005-2008 when the solar activity was very low. The terminators are for the 18.2 KHz VTX signal of the Indian Navy as observed from Indian Centre for Space Physics receiving station located in Kolkata. A total of 624 days of data have been used to obtain the mean plot. Any deviation of observations from this so-called the standardized calibration curve would point to influences by terrestrial (such as earthquakes) and extra-terrestrial events (such as solar activities). We present examples of deviations which occur in a period of 16 months and show that the correlation with seismic events is significant and typically the highest deviation takes place up to a couple of days prior to the seismic event. Simultaneous observations of such deviations from more than one station could improve the predictability of earthquakes.

  4. Low resting metabolic rate in exercise-associated amenorrhea is not due to a reduced proportion of highly active metabolic tissue compartments.

    PubMed

    Koehler, Karsten; Williams, Nancy I; Mallinson, Rebecca J; Southmayd, Emily A; Allaway, Heather C M; De Souza, Mary Jane

    2016-08-01

    Exercising women with menstrual disturbances frequently display a low resting metabolic rate (RMR) when RMR is expressed relative to body size or lean mass. However, normalizing RMR for body size or lean mass does not account for potential differences in the size of tissue compartments with varying metabolic activities. To explore whether the apparent RMR suppression in women with exercise-associated amenorrhea is a consequence of a lower proportion of highly active metabolic tissue compartments or the result of metabolic adaptations related to energy conservation at the tissue level, RMR and metabolic tissue compartments were compared among exercising women with amenorrhea (AMEN; n = 42) and exercising women with eumenorrheic, ovulatory menstrual cycles (OV; n = 37). RMR was measured using indirect calorimetry and predicted from the size of metabolic tissue compartments as measured by dual-energy X-ray absorptiometry (DEXA). Measured RMR was lower than DEXA-predicted RMR in AMEN (1,215 ± 31 vs. 1,327 ± 18 kcal/day, P < 0.001) but not in OV (1,284 ± 24 vs. 1,252 ± 17, P = 0.16), resulting in a lower ratio of measured to DEXA-predicted RMR in AMEN (91 ± 2%) vs. OV (103 ± 2%, P < 0.001). AMEN displayed proportionally more residual mass (P < 0.001) and less adipose tissue (P = 0.003) compared with OV. A lower ratio of measured to DXA-predicted RMR was associated with lower serum total triiodothyronine (ρ = 0.38, P < 0.001) and leptin (ρ = 0.32, P = 0.004). Our findings suggest that RMR suppression in this population is not the result of a reduced size of highly active metabolic tissue compartments but is due to metabolic and endocrine adaptations at the tissue level that are indicative of energy conservation.

  5. Activation of MAPK pathways due to DUSP4 loss promotes cancer stem cell-like phenotypes in basal-like breast cancer.

    PubMed

    Balko, Justin M; Schwarz, Luis J; Bhola, Neil E; Kurupi, Richard; Owens, Phillip; Miller, Todd W; Gómez, Henry; Cook, Rebecca S; Arteaga, Carlos L

    2013-10-15

    Basal-like breast cancer (BLBC) is an aggressive disease that lacks a clinically approved targeted therapy. Traditional chemotherapy is effective in BLBC, but it spares the cancer stem cell (CSC)-like population, which is likely to contribute to cancer recurrence after the initial treatment. Dual specificity phosphatase-4 (DUSP4) is a negative regulator of the mitogen-activated protein kinase (MAPK) pathway that is deficient in highly aggressive BLBCs treated with chemotherapy, leading to aberrant MAPK activation and resistance to taxane-induced apoptosis. Herein, we investigated how DUSP4 regulates the MAP-ERK kinase (MEK) and c-jun-NH2-kinase (JNK) pathways in modifying CSC-like behavior. DUSP4 loss increased mammosphere formation and the expression of the CSC-promoting cytokines interleukin (IL)-6 and IL-8. These effects were caused in part by loss of control of the MEK and JNK pathways and involved downstream activation of the ETS-1 and c-JUN transcription factors. Enforced expression of DUSP4 reduced the CD44(+)/CD24(-) population in multiple BLBC cell lines in a MEK-dependent manner, limiting tumor formation of claudin-low SUM159PT cells in mice. Our findings support the evaluation of MEK and JNK pathway inhibitors as therapeutic agents in BLBC to eliminate the CSC population.

  6. Caveat medicus: consequences of federal investigations of marketing activities of pharmaceutical suppliers of prostate cancer drugs.

    PubMed

    McKoy, June M; Lyons, E Allison; Obadina, Eniola; Carson, Kenneth; Pickard, A Simon; Schellhammer, Paul; McLeod, David; Boyd, Cynthia E; McWilliams, Norene; Sartor, Oliver; Schumock, Glen T; McCaffery, Kathryn; Bennett, Charles L

    2005-12-01

    In the course of recent health care fraud investigations against TAP Pharmaceuticals (Lake Forest, IL) and AstraZeneca International (London, United Kingdom), each pled guilty to one violation of the Prescription Drug Marketing Act, settled claims related to alleged violations of the False Claims Act without admitting guilt, and paid fines, settlements for liabilities, and reimbursements of dollar 850 million and dollar 355 million, respectively. In a unique aspect of these cases, federal investigators brought criminal charges against 14 TAP employees and investigated the billing practices of several urologists. These investigations resulted in guilty pleas from both urologists and industry employees relative to the Prescription Drug Marketing Act or the False Claims Act and probationary sentences with payments of fines and restitution to the government for urologists who cooperated with federal investigations. One uncooperative urologist was found guilty of violating the Federal False Claims Act and sentenced to 6 months of home arrest, excluded from Medicare for 5 years, required to provide 600 hours of free medical care to indigent patients and patients covered by Medicare or Medicaid, and paid fines and restitution to the government. The cases against TAP and AstraZeneca have been followed by federal and state investigations of allegedly illegal marketing practices of other pharmaceutical firms and have resulted in negotiated settlements of dollar 3.8 billion and dollar 71.5 million, respectively. Believing that an Average Wholesale Price-based reimbursement system was an important driving factor for these marketing activities, Medicare has shifted to an Average Sales Price-based reimbursement system. This is expected to greatly impact the practice of outpatient oncology nationwide.

  7. Investigations on luminescence behaviour of Ce-activated BaMgAl10 O17 phosphor.

    PubMed

    Tigga, Shalinta; Brahme, Nameeta; Bisen, D P

    2016-11-01

    The present paper describes the synthesis of cerium-doped barium magnesium aluminate phosphor by combustion method. The crystal structure of synthesized phosphor belongs to the P63 /mmc space group and is related to the β-alumina structure. The photoluminescence emission spectra exhibited a broad peak centered at 440 nm showing the Ce(3)(+) emission. The thermoluminescence properties of phosphors under ultraviolet irradiation were investigated. The activation energy was calculated by Chen's empirical method. Fracto-mechanoluminescence properties were also investigated. The phosphor showed mechanoluminescence (ML) properties without irradiation and the ML intensity increased linearly with the impact height of the moving piston. Therefore this compound may have a use as a damage sensor. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Investigations on the activity of poly(2-oxazoline) enzyme conjugates dissolved in organic solvents.

    PubMed

    Konieczny, Stefan; Krumm, Christian; Doert, Dominik; Neufeld, Katharina; Tiller, Joerg C

    2014-07-10

    The use of enzymes in organic solvents offers a great opportunity for the highly selective synthesis of complex organic compounds. In this study we investigate the POXylation of several enzymes with different polyoxazolines ranging from the hydrophilic poly(2-methyl-oxazoline) (PMOx) to the hydrophobic poly(2-heptyl-oxazoline) (PHeptOx). As reported previously on the examples of model enzymes POXylation mediated by pyromellitic acid dianhydride results in highly modified, organosoluble protein conjugates. This procedure is here extended to a larger number of proteins and optimized for the different polyoxazolines. The resulting polymer-enzyme conjugates (PEC) became soluble in different organic solvents ranging from hydrophilic DMF to even toluene. These conjugates were characterized regarding their solubility and especially their activity in organic solvents and in some cases the PECs showed significantly (up to 153,000 fold) higher activities than the respective native enzymes.

  9. Present-day biogeochemical activities of anaerobic bacteria and their relevance to future exobiological investigations

    USGS Publications Warehouse

    Oremland, R.S.

    1989-01-01

    If the primordial atmosphere was reducing, then the first microbial ecosystem was probably composed of anaerobic bacteria. However, despite the presence of an oxygen-rich atmosphere, anaerobic habitats are important, commonplace components of the Earth's present biosphere. The geochemical activities displayed by these anaerobes impact the global cycling of certain elements (e.g., C, N, S, Fe, Mn, etc.). Methane provides an obvious example of how human-enhanced activities on a global scale can influence the content of a "radiative" (i.e., infrared absorbing) trace gas in the atmosphere. Methane can be oxidized by anaerobic bacteria, but this does not appear to support their growth. Acetylene, however, does support such growth. This may form the basis for future exobiological investigations of the atmospheres of anoxic, hydrocarbon-rich planets like Jupiter and Saturn, as well as the latter's satellite Titan. ?? 1989.

  10. Investigation of the effects of extravehicular activity (EVA) gloves on performance

    NASA Technical Reports Server (NTRS)

    Bishu, Ram R.; Klute, Glenn

    1993-01-01

    The objective was to assess the effects of extravehicular activity (EVA) gloves at different pressures on human hand capabilities. A factorial experiment was performed in which three types of EVA gloves were tested at five pressure differentials. The independent variables tested in this experiment were gender, glove type, pressure differential, and glove make. Six subjects participated in an experiment where a number of dexterity measures, namely time to tie a rope, and the time to assemble a nut and bolt were recorded. Tactility was measured through a two point discrimination test. The results indicate that with EVA gloves strength is reduced by nearly 50 percent, there is a considerable reduction in dexterity, performance decrements increase with increasing pressure differential, and some interesting gender glove interactions were observed, some of which may have been due to the extent (or lack of) fit of the glove to the hand. The implications for the designer are discussed.

  11. [Medical accidents and defense activities against criminal investigation--the attorney's point of view].

    PubMed

    Goto, Sadato

    2012-09-01

    Even after the criminal investigation has begun on a medical accident, immediate defense activities can prevent false indictment. On appointing a lawyer, one has to be careful of "conflicts of interests". Defense lawyers try to reconstruct what happened on the scene with the records and the comments of the persons involved. Meanwhile, they try to nail down the medical standards in the particular case by scrutinizing medical bibliography. If they succeed in pointing out to the authorities the possibilities of not guilty verdict, arrest or indictment can be avoided.

  12. Extracellular enzyme activity assays (EEA) as a tool to investigate priming in freshwater biofilms

    NASA Astrophysics Data System (ADS)

    Wagner, K.; Sieczko, A.; Bengtsson, M. M.; Burns, N.; Herberg, E.; Battin, T.

    2012-04-01

    The priming effect describes a phenomenon, where an input of labile organic matter (LOM) increases the mineralization rate of recalcitrant organic matter (ROM). Until now priming has been mostly studied in soils, but not in aquatic ecosystems. In streams, microbial biofilms play a key role in carbon cycling. In this study, we investigate if priming contributes the metabolism of ROM in stream biofilms. We used bioreactors mimicking heterotrophic biofilms in the streambed, which were exposed to either glucose + NO3 and PO4 or to algal extracts as potential primers. Extracellular enzymatic activities were measured both in the biofilms, before and after the experiment, and in the in- and outflow of the bioreactors during the experiment. We measured the activity of β-d-glucosidase, α-d-glucosidase, β-d-xylosidase, cellobiohydrolase as enzymes involved in carbon metabolism, of leucine-aminopeptidase and endopeptidase as enzymes involved in peptides decomposition, and of esterase and phosphatase. Furthermore, phenol oxidase activity was assessed as an indicator for ROM. We evaluate these enzymatic activities to illuminate possible mechanisms underlying priming in the biofilms.

  13. Synthesis of novel Schiff's bases of highly potential biological activities and their structure investigation

    NASA Astrophysics Data System (ADS)

    Zayed, Ehab M.; Zayed, M. A.

    2015-05-01

    Novel bisaldehyde-hydrazide Schiff's bases AS1 (2,2‧-(ethane-1,2-diylbis(oxy))dibenzaldehyde terephthalohydrazide) and AS2 (N‧,N‧″-(((ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methanylylidene))di(benzohydrazide)) were prepared as new macrocyclic compounds via condensation reactions. AS1 had been prepared by condensation between (2,2‧-(ethane-1,2-diylbis(oxy))dibenzaldehyde) bisaldehyde and terephthalohydrazide in a ratio1:1. AS2 had been obtained by condensation between (2,2‧-(ethane-1,2-diylbis(oxy))dibenzaldehyde) bisaldehyde and benzohydrazide in ratio 1:2. The structures of AS1 and AS2 were characterized by elemental analysis (EA), mass (MS), FT-IR and 1H-NMR spectra, and thermal analyses (TG, DTG). The activation thermodynamic parameters such as ΔE∗, ΔH∗, ΔS∗ and ΔG∗ were calculated from the TG curves using Coats-Redfern method. It is important to investigate their molecular structures to know the active groups and weak bonds responsible for their biological activities. Consequently in the present work, the obtained thermal (TA) and mass (MS) practical results are confirmed by semi-empirical MO-calculations (MOCS) using PM3 procedure. Their biological activities had been tested in vitro against Escherichia coli, Proteus vulgaris, Bacillus subtilis and Staphylococcus aurous bacteria in order to assess their anti-microbial potential.

  14. Orally Administered Salacia reticulata Extract Reduces H1N1 Influenza Clinical Symptoms in Murine Lung Tissues Putatively Due to Enhanced Natural Killer Cell Activity

    PubMed Central

    Romero-Pérez, Gustavo A.; Egashira, Masayo; Harada, Yuri; Tsuruta, Takeshi; Oda, Yuriko; Ueda, Fumitaka; Tsukahara, Takamitsu; Tsukamoto, Yasuhiro; Inoue, Ryo

    2016-01-01

    Influenza is a major cause of respiratory tract infection. Although most cases do not require further hospitalization, influenza periodically causes epidemics in humans that can potentially infect and kill millions of people. To countermeasure this threat, new vaccines need to be developed annually to match emerging influenza viral strains with increased resistance to existing vaccines. Thus, there is a need for finding and developing new anti-influenza viral agents as alternatives to current treatments. Here, we tested the antiviral effects of an extract from the stems and roots of Salacia reticulata (SSRE), a plant rich in phytochemicals, such as salacinol, kotalanol, and catechins, on H1N1 influenza virus-infected mice. Following oral administration of 0.6 mg/day of SSRE, the incidence of coughing decreased in 80% of mice, and only one case of severe pulmonary inflammation was detected. Moreover, when compared with mice given Lactobacillus casei JCM1134, a strain previously shown to help increase in vitro natural killer (NK) cell activity, SSRE-administered mice showed greater and equal NK cell activity in splenocytes and pulmonary cells, respectively, at high effector cell:target cell ratios. Next, to test whether or not SSRE would exert protective effects against influenza in the absence of gut microbiota, mice were given antibiotics before being inoculated influenza virus and subsequently administered SSRE. SSRE administration induced an increase in NK cell activity in splenocytes and pulmonary cells at levels similar to those detected in mice not treated with antibiotics. Based on our results, it can be concluded that phytochemicals in the SSRE exerted protective effects against influenza infection putatively via modulation of the immune response, including enhancement of NK cell activity, although some protective effects were not necessarily through modulation of gut microbiota. Further investigation is necessary to elucidate the molecular mechanisms

  15. Investigation of biological activity of polar extracts isolated from Phlomis crinita Cav ssp. mauritanica Munby.

    PubMed

    Limem-Ben Amor, Ilef; Skandrani, Ines; Boubaker, Jihed; Ben Sghaïer, Mohamed; Neffati, Aicha; Bhouri, Wissem; Bouhlel, Ines; Chouchane, Nabil; Kilani, Soumaya; Guedon, Emmanuel; Ghoul, Mohamed; Ghedira, Kamel; Chekir-Ghedira, Leila

    2009-01-01

    The lyophilized infusion, the methanol, the ethyl acetate, and the total oligomer flavonoid (TOF)-enriched extracts prepared from the dried leaves of Phlomis crinita Cav. ssp. mauritanica Munby were investigated for the contents of flavonoids, tannins, coumarines and steroids. Antibacterial activity was investigated toward five bacterial strains. An inhibitory effect was observed against Staphyllococcus aureus and Enterococcus feacalis, and the minimal inhibitory concentrations ranged from 2.5 to 5 mg/mL of extract. The tested extracts exhibit an important free radical scavenging activity toward the 1,1-diphenyl 2-picrylhydrazyl (DPPH) free radical; with IC(50) values of 30.5, 6, 32, and 31.5 microg/mL, respectively, in the presence of lyophilized infusion, the TOF, the methanol, and the ethyl acetate extracts. Genotoxic and antigenotoxic properties of the different extracts were studied by using the SOS chromotest with Escherichia coli PQ37. The lyophilized infusion and TOF extracts obtained from P. crinita ssp. mauritanica showed no genotoxicity, whereas methanol and ethyl acetate extracts are considered as marginally genotoxic. On the other hand, we showed that each extract inhibited the mutagenicity induced by aflatoxin B1 (AFB1) (10 microg/assay) and nifuroxazide (NF) (10 microg/assay). The ethyl acetate extract showed the strongest level of protection toward the genotoxicity induced by both directly and indirectly genotoxic NF and AFB1. These tests proved that the lyophilized infusion possesses an antiradical activity likewise, it showed no genotoxic effect; that is why we choose this extract to assess its antiulcerogenic activity by using an ethanol-induced ulcerogenesis model in the rat. This test demonstrates that 300 mg/kg of a P. crinita ssp. mauritanica lyophilized infusion was more effective than the reference compound, cimetidine.

  16. Investigating diet and physical activity in Malaysia: education and family history of diabetes relate to lower levels of physical activity.

    PubMed

    Tam, Cai Lian; Bonn, Gregory; Yeoh, Si Han; Wong, Chee Piau

    2014-01-01

    The National Health and Morbidity Survey (NHMS, 2011), estimates that the number of Malaysian adults suffering from type 2 diabetes has increased from 8.3 to 31.2% since 1996. This study is a preliminary investigation of possible factors contributing to this epidemic. Knowledge of diabetes, health locus of control, diet and exercise habits, as well as family history, education level and other demographic factors to better understand the correlates of risky and healthy behaviors. This was done as part of a larger initiative to improve prevention efforts. Questionnaires were completed by 770 individuals from three Malaysian states: Selangor, Penang, and Terengganu. Findings showed that people with better health knowledge and those who have a family history of type 2 diabetes were more likely to have healthy diets. Also, health knowledge related to lower alcohol consumption. Participants with diabetic family members, however, also reported higher levels of stress. Counterintuitively, higher educational levels, higher internal locus of control, better health knowledge, as well as a family history of diabetes all correlated with lower levels of physical activity. Thus, it is suggested that, while increasing health knowledge will be important in addressing the type 2 diabetes epidemic in Malaysia, especially in relation to diet, other cultural factors, specifically norms related to exercise and physical activity, also need to be addressed if the spread of type 2 diabetes is to be addressed over the long term.

  17. Age-associated impairement in endpoint accuracy of goal-directed contractions performed with two fingers is due to altered activation of the synergistic muscles.

    PubMed

    Chen, Yen-Ting; Pinto Neto, Osmar; de Miranda Marzullo, Ana Carolina; Kennedy, Deanna M; Fox, Emily J; Christou, Evangelos A

    2012-07-01

    The purpose of this study was to determine whether older adults compared with young adults exhibit impaired end-point accuracy during a two-finger task due to altered activation of the contributing synergistic muscles. Nine young (21.3 years ± 1.6 years, 4 men) and 9 older (73.1 years ± 6.4 years, 5 men) were instructed to accurately match the center of a target with concurrent abduction of the index and little fingers (synergistic two-finger task). The target comprised of 20% MVC and 200 ms. Visual feedback of the force trajectory and target was provided 1s after each trial. Subjects completed 40 trials and the last 10 were used for analysis. Endpoint accuracy was quantified as the normalized deviation from the target in terms of peak force (peak force error), time-to-peak force (time-to-peak force error), and a combination of the two (overall error). Motor output variability was quantified as the standard deviation and coefficient of variation (CV) of peak force and time to peak force. The neural activation of the involved synergist muscles (first dorsal interosseus (FDI) and abductor digiti minimi (ADM)) was quantified with the electromyography (EMG) amplitude (root mean square) and its frequency structure (wavelet analysis). Older adults exhibited significantly greater peak force (46.7 ± 10% vs. 24.9 ± 3.2%) and overall endpoint error (68.5 ± 9.7% vs. 41.7 ± 4.3%), whereas the time to peak force error was similar for the two age groups. Older adults also exerted greater peak force variability than young adults, as quantified by the CV of peak force (34.3 ± 3.5% vs. 24.1 ± 2.3%). The greater peak force error in older adults was associated with changes in the activation of the ADM muscle but not the FDI. Specifically, greater peak force error was associated with greater power from 13-30 Hz and lesser power from 30-60 Hz. These results, therefore, suggest that older adults compared with young adults exhibit impaired endpoint force accuracy during a two

  18. In vitro model systems to investigate bile salt export pump (BSEP) activity and drug interactions: A review.

    PubMed

    Cheng, Yaofeng; Woolf, Thomas F; Gan, Jinping; He, Kan

    2016-08-05

    The bile salt export pump protein (BSEP), expressed on the canalicular membranes of hepatocytes, is primarily responsible for the biliary excretion of bile salts. The inhibition of BSEP transport activity can lead to an increase in intracellular bile salt levels and liver injury. This review discusses the various in vitro assays currently available for assessing the effect of drugs or other chemical entities to modulate BSEP transport activity. BSEP transporter assays use one of the following platforms: Xenopus laevis oocytes; canalicular membrane vesicles (CMV); BSEP-expressed membrane vesicles; cell lines expressing BSEP; sandwich cultured hepatocytes (SCH); and hepatocytes in suspension. Two of these, BSEP-expressed insect membrane vesicles and sandwich cultured hepatocytes, are the most commonly used assays. BSEP membrane vesicles prepared from transfected insect cells are useful for assessing BSEP inhibition or substrate specificity and exploring mechanisms of BSEP-associated genetic diseases. This model can be applied in a high-throughput format for discovery-drug screening. However, experimental results from use of membrane vesicles may lack physiological relevance and the model does not allow for investigation of in situ metabolism in modulation of BSEP activity. Hepatocyte-based assays that use the SCH format provide results that are generally more physiologically relevant than membrane assays. The SCH model is useful in detailed studies of the biliary excretion of drugs and BSEP inhibition, but due to the complexity of SCH preparation, this model is used primarily for determining biliary clearance and BSEP inhibition in a limited number of compounds. The newly developed hepatocyte in suspension assay avoids many of the complexities of the SCH method. The use of pooled cryopreserved hepatocytes in suspension minimizes genetic variance and individual differences in BSEP activity and also provides the opportunity for higher throughput screening and cross

  19. Investigation of Performance of Concrete and Concreting Materials Exposed to Natural Weathering. Volume 1. Active Investigations. Revision

    DTIC Science & Technology

    1980-08-01

    Wilson, and G. S. Harris. Mr. Thornton prepared this distribution. During the preparation of this report COL Edmund H. Lang, CE, was Director of the...Materisa 10- by 20-In, cores 75 21 Oct 1958 8 Investigation, tese D leach 1 Cement-.Spscrnent Materisls 2-ft cubes 20 11 Oct 1958 8 Back 8 Pssamauoddy...pieces 1 0 Aug 1958 30 leack 2 *uIt AgrgTeestgatio 2-t cures 160 0 Nov 1962 35 lec 2a Deci etPrps -u qurs8 p 1963 35 leach A- Qmzimm Allowtbe Ivter

  20. Modification of the solar activity indices in the International Reference Ionosphere IRI and IRI-Plas models due to recent revision of sunspot number time series

    NASA Astrophysics Data System (ADS)

    Gulyaeva, Tamara

    2016-08-01

    The International Reference Ionosphere (IRI) imports global effective ionospheric IG12 index based on ionosonde measurements of the critical frequency foF2 as a proxy of solar activity. Similarly, the global electron content (GEC), smoothed by the sliding 12-months window (GEC12), is used as a solar proxy in the ionospheric and plasmaspheric model IRI-Plas. GEC has been calculated from global ionospheric maps of total electron content (TEC) since 1998 whereas its productions for the preceding years and predictions for the future are made with the empirical model of the linear dependence of GEC on solar activity. At present there is a need to re-evaluate solar and ionospheric indices in the ionospheric models due to the recent revision of sunspot number (SSN2) time series, which has been conducted since 1st July, 2015 [Clette et al., 2014]. Implementation of SSN2 instead of the former SSN1 series with the ionospheric model could increase model prediction errors. A formula is proposed to transform the smoothed SSN212 series to the proxy of the former basic SSN112=R12 index, which is used by IRI and IRI-Plas models for long-term ionospheric predictions. Regression relationships are established between GEC12, the sunspot number R12, and the proxy solar index of 10.7 cm microwave radio flux, F10.712. Comparison of calculations by the IRI-Plas and IRI models with observations and predictions for Moscow during solar cycles 23 and 24 has shown the advantage of implementation of GEC12 index with the IRI-Plas model.

  1. HMG-CoA reductase inhibitory activity and phytocomponent investigation of Basella alba leaf extract as a treatment for hypercholesterolemia

    PubMed Central

    Baskaran, Gunasekaran; Salvamani, Shamala; Ahmad, Siti Aqlima; Shaharuddin, Noor Azmi; Pattiram, Parveen Devi; Shukor, Mohd Yunus

    2015-01-01

    The enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of the mevalonate pathway that produces cholesterol. Inhibition of HMG-CoA reductase reduces cholesterol biosynthesis in the liver. Synthetic drugs, statins, are commonly used for the treatment of hypercholesterolemia. Due to the side effects of statins, natural HMG-CoA reductase inhibitors of plant origin are needed. In this study, 25 medicinal plant methanol extracts were screened for anti-HMG-CoA reductase activity. Basella alba leaf extract showed the highest inhibitory effect at about 74%. Thus, B. alba was examined in order to investigate its phytochemical components. Gas chromatography with tandem mass spectrometry and reversed phase high-performance liquid chromatography analysis revealed the presence of phenol 2,6-bis(1,1-dimethylethyl), 1-heptatriacotanol, oleic acid, eicosyl ester, naringin, apigenin, luteolin, ascorbic acid, and α-tocopherol, which have been reported to possess antihypercholesterolemic effects. Further investigation of in vivo models should be performed in order to confirm its potential as an alternative treatment for hypercholesterolemia and related cardiovascular diseases. PMID:25609924

  2. An investigation of reduced western disturbance activity over Northwest India in November - December 2015 compared to 2014 - A case study

    NASA Astrophysics Data System (ADS)

    Basu, Soumik; Bieniek, Peter A.; Deoras, Akshay

    2017-02-01

    In November-December of 2015, Northwestern India received very low precipitation due to anomalously low Western Disturbances (WDs) activity. The resulting lack of sufficient precipitation and soil moisture hampered the growth of winter crops leading to significant agricultural losses. Relatively stable weather in the absence of precipitation and WDs contributed to extremely high air pollution in New Delhi and also significantly degraded the air quality in many cities of Northwestern India leading to severe health issues. Despite the fact that WDs play a very important role in India's winter weather, limited research has been done to investigate the causes of their inter-annual variability. A case study using NCEP/NCAR Reanalysis, CMAP precipitation and NOAA Extended Reconstructed Sea Surface Temperature data is evaluated in this paper to better understand the atmospheric drivers of WDs in order to help fill the gap in knowledge. Results show that elevated Sea Surface Temperatures over the North Indian Ocean likely lead to atmospheric circulation anomalies that led to branching and weakening of the subtropical jet stream and weakening of vertical wind shear over Northwestern India. These conditions created an unfavorable environment for the propagation of WDs. However, there was an intensification of vertical wind shear over mid-latitude Eurasia along with increased storm activity. This weakened the Eurasian anticyclone resulting in warmer surface air temperatures over the midlatitudes that led to a redistribution of the meridional temperature gradient.

  3. Investigating the relationship of lightning activity and rainfall: A case study for Crete Island

    NASA Astrophysics Data System (ADS)

    Iordanidou, V.; Koutroulis, A. G.; Tsanis, I. K.

    2016-05-01

    The relationship of lightning activity and rainfall is investigated for rain events of variable intensity. Rain data from 22 gauging stations over the island of Crete and lightning activity from the Global Lightning Network including both cloud-to-ground and some cloud flashes are analyzed for the period September 2012 to June 2014. Local thunderstorms' characteristics are investigated both individually as well as in groups according to the results of k-means clustering algorithm in 3 dimensions (space (x, y) and time (t)) in which the number of clusters is decided by G-means algorithm. Correlation of non-zero pairs of rain intensity and number of flashes is examined at various time intervals, time lags and effective radii. Also, correlation of flash count within 50 km radius around the stations is examined for the rain events of maximum hourly intensity for each gauging station. The highest coincidence of lightning clusters with intense rain events reaches 60% when gauges are 25-30 km from the cluster center. Maximum correlation within non-zero pairs of rain intensity and flashes number is obtained for more intense rain (99th percentile) and for increased flash count within the searching area (more than 10 flashes). Also, correlation is stronger for shorter time windows. The findings of this study improve the understanding of thunderstorm events and could provide staple information for the improvement of forecasting extreme events.

  4. Investigation on mechanism of antifungal activity of eugenol against Trichophyton rubrum.

    PubMed

    de Oliveira Pereira, Fillipe; Mendes, Juliana Moura; de Oliveira Lima, Edeltrudes

    2013-07-01

    Trichophyton rubrum is a worldwide agent responsible for chronic cases of dermatophytosis which have high rates of resistance to antifungal drugs. Attention has been drawn to the antimicrobial activity of aromatic compounds because of their promising biological properties. Therefore, we investigated the antifungal activity of eugenol against 14 strains of T. rubrum which involved determining its minimum inhibitory concentration (MIC) and effects on mycelial growth (dry weight), conidial germination and morphogenesis. The effects of eugenol on the cell wall (sorbitol protect effect) and the cell membrane (release of intracellular material, complex with ergosterol, ergosterol synthesis) were investigated. Eugenol inhibited the growth of 50% of T. rubrum strains employed in this study at an MIC = 256 μg/ml, as well as mycelial growth and conidia germination. It also caused abnormalities in the morphology of the dermatophyte in that we found wide, short, twisted hyphae and decreased conidiogenesis. The results of these studies on the mechanisms of action suggested that eugenol exerts antifungal effects on the cell wall and cell membrane of T. rubrum. Eugenol act on cell membrane by a mechanism that seems to involve the inhibition of ergosterol biosynthesis. The lower ergosterol content interferes with the integrity and functionality of the cell membrane. Finally, our studies support the potential use of the eugenol as an antifungal agent against T. rubrum.

  5. Investigation of frontal lobe activation with fNIRS and systemic changes during video gaming.

    PubMed

    Tachtsidis, Ilias; Papaioannou, Antonis

    2013-01-01

    Frontal lobe activation caused by tasks such as videogames can be investigated using multichannel near-infrared spectroscopy (fNIRS), sometimes called optical topography. The aims of this study are to investigate the effects of video gaming (fighting and puzzle games) in the brain and the systemic physiology and to determine whether systemic responses during the gaming task are associated with the measurement of localised cerebral haemodynamic changes as measured by fNIRS. We used a continuous-wave 8-channel fNIRS system to measure the changes in concentration of oxy-haemoglobin (HbO2) and deoxy-haemoglobin (HHb) and changes in total haemoglobin (ΔtHb = ΔHbO2 + ΔHHb) over the frontal lobe in 30 healthy volunteers. The Portapres system was used to measure mean blood pressure (MBP) and heart rate (HR), and a laser Doppler was employed to measure the changes in scalp blood flow (or flux). Even though we observed significant changes in systemic variables during gaming, in particular in scalp flow, we also managed to see localised activation patterns over the frontal polar (FP1) region. However, in some channels over the frontal lobe, we also observed significant correlations between the HbO2 and systemic variables.

  6. Investigating Climate Change Issues With Web-Based Geospatial Inquiry Activities

    NASA Astrophysics Data System (ADS)

    Dempsey, C.; Bodzin, A. M.; Sahagian, D. L.; Anastasio, D. J.; Peffer, T.; Cirucci, L.

    2011-12-01

    In the Environmental Literacy and Inquiry middle school Climate Change curriculum we focus on essential climate literacy principles with an emphasis on weather and climate, Earth system energy balance, greenhouse gases, paleoclimatology, and how human activities influence climate change (http://www.ei.lehigh.edu/eli/cc/). It incorporates a related set of a framework and design principles to provide guidance for the development of the geospatial technology-integrated Earth and environmental science curriculum materials. Students use virtual globes, Web-based tools including an interactive carbon calculator and geologic timeline, and inquiry-based lab activities to investigate climate change topics. The curriculum includes educative curriculum materials that are designed to promote and support teachers' learning of important climate change content and issues, geospatial pedagogical content knowledge, and geographic spatial thinking. The curriculum includes baseline instructional guidance for teachers and provides implementation and adaptation guidance for teaching with diverse learners including low-level readers, English language learners and students with disabilities. In the curriculum, students use geospatial technology tools including Google Earth with embedded spatial data to investigate global temperature changes, areas affected by climate change, evidence of climate change, and the effects of sea level rise on the existing landscape. We conducted a designed-based research implementation study with urban middle school students. Findings showed that the use of the Climate Change curriculum showed significant improvement in urban middle school students' understanding of climate change concepts.

  7. Investigation of shallow gas hydrate occurrence and gas seep activity on the Sakhalin continental slope, Russia

    NASA Astrophysics Data System (ADS)

    Jin, Young Keun; Baranov, Boris; Obzhirov, Anatoly; Salomatin, Alexander; Derkachev, Alexander; Hachikubo, Akihiro; Minami, Hrotsugu; Kuk Hong, Jong

    2016-04-01

    The Sakhalin continental slope has been a well-known gas hydrate area since the first finding of gas hydrate in 1980's. This area belongs to the southernmost glacial sea in the northern hemisphere where most of the area sea is covered by sea ice the winter season. Very high organic carbon content in the sediment, cold sea environment, and active tectonic regime in the Sakhalin slope provide a very favorable condition for occurring shallow gas hydrate accumulation and gas emission phenomena. Research expeditions under the framework of a Korean-Russian-Japanese long-term international collaboration projects (CHAOS, SSGH-I, SSGH-II projects) have been conducted to investigate gas hydrate occurrence and gas seepage activities on the Sakhalin continental slope, Russia from 2003 to 2015. During the expeditions, near-surface gas hydrate samples at more than 30 sites have been retrieved and hundreds of active gas seepage structures on the seafloor were newly registered by multidisciplinary surveys. The gas hydrates occurrence at the various water depths from about 300 m to 1000 m in the study area were accompanied by active gas seepage-related phenomena in the sub-bottom, on the seafloor, and in the water column: well-defined upward gas migration structures (gas chimney) imaged by high-resolution seismic, hydroacoustic anomalies of gas emissions (gas flares) detected by echosounders, seafloor high backscatter intensities (seepage structures) imaged by side-scan sonar and bathymetric structures (pockmarks and mounds) mapped by single/multi-beam surveys, and very shallow SMTZ (sulphate-methane transition zone) depths, strong microbial activities and high methane concentrations measured in sediment/seawater samples. The highlights of the expeditions are shallow gas hydrate occurrences around 300 m in the water depth which is nearly closed to the upper boundary of gas hydrate stability zone in the area and a 2,000 m-high gas flare emitted from the deep seafloor.

  8. The investigation of antibacterial activity of selected native plants from North of Iran

    PubMed Central

    Koohsari, H; Ghaemi, EA; Sadegh Sheshpoli, M; Jahedi, M; Zahiri, M

    2015-01-01

    Plant derived products have been used for medicinal purposes during centuries. Bacterial resistance to currently used antibiotics has become a concern to public health. The development of bacterial super resistant strains has resulted in the currently used antibiotic agents failing to end many bacterial infections. For this reason, the search is ongoing for new antimicrobial agents, both by the design and by the synthesis of new agents, or through the search of natural sources for yet undiscovered antimicrobial agents. Herbal medications in particular have seen a revival of interest due to a perception that there is a lower incidence of adverse reactions to plant preparations compared to synthetic pharmaceuticals. Coupled with the reduced costs of plant preparations, this makes the search for natural therapeutics an attractive option. This research was carried out to assess the antibacterial activity aqueous and ethanolic extracts of six Azadshahr township Native plants in north of Iran against six species of pathogen bacteria by using three methods of Disk diffusion, Well method and MBC. The results of this research indicated that the effect of ethanol extracts were more than aqueous extract and among six plants, Lippia citriodora and Plantago major ethanol extract had the most antibacterial activity in any of the three methods. Gram-positive bacteria were more sensitive than gram-negative bacteria. Staphylococcus epidermidis and Staphylococcus aureus were the most susceptible Gram-positive bacteria.

  9. Experimental investigation and CFD simulation of active damping mechanism for propellant slosh in spacecraft launch systems

    NASA Astrophysics Data System (ADS)

    Leuva, Dhawal

    2011-07-01

    Motion of propellant in the liquid propellant tanks due to inertial forces transferred from actions like stage separation and trajectory correction of the launch vehicle is known as propellant slosh. If unchecked, propellant slosh can reach resonance and lead to complete loss of the spacecraft stability, it can change the trajectory of the vehicle or increase consumption of propellant from the calculated requirements, thereby causing starvation of the latter stages of the vehicle. Predicting the magnitude of such slosh events is not trivial. Several passive mechanisms with limited operating range are currently used to mitigate the effects of slosh. An active damping mechanism concept developed here can operate over a large range of slosh frequencies and is much more effective than passive damping devices. Spherical and cylindrical tanks modeled using the ANSYS CFX software package considers the free surface of liquid propellant exposed to atmospheric pressure. Hydrazine is a common liquid propellant and since it is toxic, it cannot be used in experiment. But properties of hydrazine are similar to the properties of water; therefore water is substituted as propellant for experimental study. For close comparison of the data, water is substituted as propellant in CFD simulation. The research is done in three phases. The first phase includes modeling free surface slosh using CFD and validation of the model by comparison to previous experimental results. The second phase includes developing an active damping mechanism and simulating the behavior using a CFD model. The third phase includes experimental development of damping mechanism and comparing the CFD simulation to the experimental results. This research provides an excellent tool for low cost analysis of damping mechanisms for propellant slosh as well as proves that the concept of an active damping mechanism developed here, functions as expected.

  10. Current activities and results of the Long Duration Exposure Facility Meteoroid and Debris Special Investigation Group

    NASA Technical Reports Server (NTRS)

    See, Thomas H.; Leago, Kimberly S.; Warren, Jack L.; Bernhard, Ronald P.; Zolensky, Michael E.

    1994-01-01

    Fiscal Year 1994 will bring to a close the initial investigative activities associated with the Long Duration Exposure Facility (LDEF). LDEF was a 14-faced spacecraft (i.e., 12-sided cylinder and two ends) which housed 54 different experimental packages in low-Earth orbit (LEO) from Apr. 1984 to Jan. 1990 (i.e., for approx. 5.75 years). Since LDEF's return, the Meteoroid & Debris Special Investigation Group (M&D SIG) has been examining various LDEF components in order to better understand and define the LEO particulate environment. Members of the M&D SIG at JSC in Houston, TX have been contributing to these studies by carefully examining and documenting all impact events found on LDEF's 6061-T6 aluminum Intercostals (i.e., one of the spacecraft's structural frame components). Unlike all other hardware on LDEF, the frame exposed significantly large surface areas of a single homogeneous material in all (i.e., 26) possible LDEF pointing directions. To date, 28 of the 68 Intercostals in the possession of the M&D SIG have been documented. This data, as well as similar information from various LDEF investigators, can be accessed through the M&D SIG Database which is maintained at JSC.

  11. Investigation of the Activity of the Microorganisms in a Reblochon-Style Cheese by Metatranscriptomic Analysis.

    PubMed

    Monnet, Christophe; Dugat-Bony, Eric; Swennen, Dominique; Beckerich, Jean-Marie; Irlinger, Françoise; Fraud, Sébastien; Bonnarme, Pascal

    2016-01-01

    The microbial communities in cheeses are composed of varying bacteria, yeasts, and molds, which contribute to the development of their typical sensory properties. In situ studies are needed to better understand their growth and activity during cheese ripening. Our objective was to investigate the activity of the microorganisms used for manufacturing a surface-ripened cheese by means of metatranscriptomic analysis. The cheeses were produced using two lactic acid bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus), one ripening bacterium (Brevibacterium aurantiacum), and two yeasts (Debaryomyces hansenii and Geotrichum candidum). RNA was extracted from the cheese rinds and, after depletion of most ribosomal RNA, sequencing was performed using a short-read sequencing technology that generated ~75 million reads per sample. Except for B. aurantiacum, which failed to grow in the cheeses, a large number of CDS reads were generated for the inoculated species, making it possible to investigate their individual transcriptome over time. From day 5 to 35, G. candidum accounted for the largest proportion of CDS reads, suggesting that this species was the most active. Only minor changes occurred in the transcriptomes of the lactic acid bacteria. For the two yeasts, we compared the expression of genes involved in the catabolism of lactose, galactose, lactate, amino acids, and free fatty acids. During ripening, genes involved in ammonia assimilation and galactose catabolism were down-regulated in the two species. Genes involved in amino acid catabolism were up-regulated in G. candidum from day 14 to day 35, whereas in D. hansenii, they were up-regulated mainly at day 35, suggesting that this species catabolized the cheese amino acids later. In addition, after 35 days of ripening, there was a down-regulation of genes involved in the electron transport chain, suggesting a lower cellular activity. The present study has exemplified how

  12. Investigation of the Activity of the Microorganisms in a Reblochon-Style Cheese by Metatranscriptomic Analysis

    PubMed Central

    Monnet, Christophe; Dugat-Bony, Eric; Swennen, Dominique; Beckerich, Jean-Marie; Irlinger, Françoise; Fraud, Sébastien; Bonnarme, Pascal

    2016-01-01

    The microbial communities in cheeses are composed of varying bacteria, yeasts, and molds, which contribute to the development of their typical sensory properties. In situ studies are needed to better understand their growth and activity during cheese ripening. Our objective was to investigate the activity of the microorganisms used for manufacturing a surface-ripened cheese by means of metatranscriptomic analysis. The cheeses were produced using two lactic acid bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus), one ripening bacterium (Brevibacterium aurantiacum), and two yeasts (Debaryomyces hansenii and Geotrichum candidum). RNA was extracted from the cheese rinds and, after depletion of most ribosomal RNA, sequencing was performed using a short-read sequencing technology that generated ~75 million reads per sample. Except for B. aurantiacum, which failed to grow in the cheeses, a large number of CDS reads were generated for the inoculated species, making it possible to investigate their individual transcriptome over time. From day 5 to 35, G. candidum accounted for the largest proportion of CDS reads, suggesting that this species was the most active. Only minor changes occurred in the transcriptomes of the lactic acid bacteria. For the two yeasts, we compared the expression of genes involved in the catabolism of lactose, galactose, lactate, amino acids, and free fatty acids. During ripening, genes involved in ammonia assimilation and galactose catabolism were down-regulated in the two species. Genes involved in amino acid catabolism were up-regulated in G. candidum from day 14 to day 35, whereas in D. hansenii, they were up-regulated mainly at day 35, suggesting that this species catabolized the cheese amino acids later. In addition, after 35 days of ripening, there was a down-regulation of genes involved in the electron transport chain, suggesting a lower cellular activity. The present study has exemplified how

  13. Investigating the antifungal activity of TiO2 nanoparticles deposited on branched carbon nanotube arrays

    NASA Astrophysics Data System (ADS)

    Darbari, S.; Abdi, Y.; Haghighi, F.; Mohajerzadeh, S.; Haghighi, N.

    2011-06-01

    Branched carbon nanotube (CNT) arrays were synthesized by plasma-enhanced chemical vapour deposition on a silicon substrate. Ni was used as the catalyst and played an important role in the realization of branches in vertically aligned nanotubes. TiO2 nanoparticles on the branched CNTs were produced by atmospheric pressure chemical vapour deposition followed by a 500 °C annealing step. Transmission and scanning electron microscopic techniques were used to study the morphology of the TiO2/branched CNT structures while x-ray diffraction and Raman spectroscopy were used to verify the characteristics of the prepared nanostructures. Their antifungal effect on Candida albicans biofilms under visible light was investigated and compared with the activity of TiO2/CNT arrays and thin films of TiO2. The TiO2/branched CNTs showed a highly improved photocatalytic antifungal activity in comparison with the TiO2/CNTs and TiO2 film. The excellent visible light-induced photocatalytic antifungal activity of the TiO2/branched CNTs was attributed to the generation of electron-hole pairs by visible light excitation with a low recombination rate, in addition to the high surface area provided for the interaction between the cells and the nanostructures. Scanning electron microscopy was used to observe the resulting morphological changes in the cell body of the biofilms existing on the antifungal samples.

  14. Investigation of the Antimicrobial Activity of Bacillus licheniformis Strains Isolated from Retail Powdered Infant Milk Formulae.

    PubMed

    Alvarez-Ordóñez, Avelino; Begley, Máire; Clifford, Tanya; Deasy, Thérèse; Considine, Kiera; O'Connor, Paula; Ross, R Paul; Hill, Colin

    2014-03-01

    This study investigated the potential antimicrobial activity of ten Bacillus licheniformis strains isolated from retail infant milk formulae against a range of indicator (Lactococcus lactis, Lactobacillus bulgaricus and Listeria innocua) and clinically relevant (Listeria monocytogenes, Staphylococcus aureus, Streptococcus agalactiae, Salmonella Typhimurium and Escherichia coli) microorganisms. Deferred antagonism assays confirmed that all B. licheniformis isolates show antimicrobial activity against the Gram-positive target organisms. PCR and matrix-assisted laser desorption ionization time-of-flight mass spectrometry analyses indicated that four of the B. licheniformis isolates produce the bacteriocin lichenicidin. The remaining six isolates demonstrated a higher antimicrobial potency than lichenicidin-producing strains. Further analyses identified a peptide of ~1,422 Da as the most likely bioactive responsible for the antibacterial activity of these six isolates. N-terminal sequencing of the ~1,422 Da peptide from one strain identified it as ILPEITXIFHD. This peptide shows a high homology to the non-ribosomal peptides bacitracin and subpeptin, known to be produced by Bacillus spp. Subsequent PCR analyses demonstrated that the six B. licheniformis isolates may harbor the genetic machinery needed for the synthesis of a non-ribosomal peptide synthetase similar to those involved in production of subpeptin and bacitracin, which suggests that the ~1,422 Da peptide might be a variant of subpeptin and bacitracin.

  15. Stiffening hydrogels for investigating the dynamics of hepatic stellate cell mechanotransduction during myofibroblast activation

    NASA Astrophysics Data System (ADS)

    Caliari, Steven R.; Perepelyuk, Maryna; Cosgrove, Brian D.; Tsai, Shannon J.; Lee, Gi Yun; Mauck, Robert L.; Wells, Rebecca G.; Burdick, Jason A.

    2016-02-01

    Tissue fibrosis contributes to nearly half of all deaths in the developed world and is characterized by progressive matrix stiffening. Despite this, nearly all in vitro disease models are mechanically static. Here, we used visible light-mediated stiffening hydrogels to investigate cell mechanotransduction in a disease-relevant system. Primary hepatic stellate cell-seeded hydrogels stiffened in situ at later time points (following a recovery phase post-isolation) displayed accelerated signaling kinetics of both early (Yes-associated protein/Transcriptional coactivator with PDZ-binding motif, YAP/TAZ) and late (alpha-smooth muscle actin, α-SMA) markers of myofibroblast differentiation, resulting in a time course similar to observed in vivo activation dynamics. We further validated this system by showing that α-SMA inhibition following substrate stiffening resulted in attenuated stellate cell activation, with reduced YAP/TAZ nuclear shuttling and traction force generation. Together, these data suggest that stiffening hydrogels may be more faithful models for studying myofibroblast activation than static substrates and could inform the development of disease therapeutics.

  16. An investigation into active vibration isolation based on predictive control: Part I: Energy source control

    NASA Astrophysics Data System (ADS)

    Fei, H. Z.; Zheng, G. T.; Liu, Z. G.

    2006-09-01

    We report the results of a recent study for the active vibration isolation with whole-spacecraft vibration isolation as an application background into which three parts are divided: (i) energy source control, (ii) nonlinearity and time delay, (iii) implementation and experiment. This paper is the first in this three-part series report, which presents theoretical and experimental investigations into pressure tracking system for energy source control of the isolator. Considering the special environment of the rocket and expected characteristics of actuators, where the isolator will be arranged between the rocket and the spacecraft, pneumatic actuator is proposed to realize the active isolation control. In order to improve the dynamic characteristics of the pneumatic isolator, a cascade control algorithm with double loop structure and predictive control algorithm for pressure tracking control of the inner loop are proposed. In the current paper, a pressure tracking control system using model predictive control (MPC) is studied first. A pneumatic model around pressure work point is built firstly by simplifying the flow equation of valve's orifices and pressure differential equation of the chambers. With this model, an MPC algorithm in the state space is developed, and problems including control parameter choice and command horizon generator are discussed in detail. In addition, by adding model error correction loop and velocity compensation feedback, effects of model uncertainty and volume variation of chambers are reduced greatly. Thus with this design, the real-time pressure tracking can be guaranteed, and so that the active control system can work at higher frequency range.

  17. Investigation of activation cross-section data of proton induced nuclear reactions on rhenium.

    PubMed

    Ditrói, F; Tárkányi, F; Takács, S; Hermanne, A; Yamazaki, H; Baba, M; Mohammadi, A; Ignatyuk, A V

    2013-07-01

    In the frame of systematic investigations of activation cross-section data for different applications the excitation functions of (nat)Re(p,x)(185)Os, (183m)Os, (183g)Os, (182)Os, (181m)Os, (186g)Re, (184m)Re, (184g)Re, (183)Re, (182m)Re, (182g)Re and (181g)Re reactions were measured up to 70MeV. The data for the (nat)Re(p,x) (183m)Os, (183g)Os, (182)Os, (181g)Os,(186g)Re, (184m)Re,(182m)Re, (182g)Re, and (181)Re reactions are reported for the first time. The activation method, the stacked foil irradiation technique and γ-spectroscopy for activity detection were used. The experimental data were compared with predictions of three theoretical codes. From the measured cross-section thick target integral yields were also calculated and presented.

  18. Investigating the lytic activity and structural properties of Staphylococcus aureus phenol soluble modulin (PSM) peptide toxins.

    PubMed

    Laabei, Maisem; Jamieson, W David; Yang, Yi; van den Elsen, Jean; Jenkins, A Toby A

    2014-12-01

    The ubiquitous bacterial pathogen, Staphylococcus aureus, expresses a large arsenal of virulence factors essential for pathogenesis. The phenol-soluble modulins (PSMs) are a family of cytolytic peptide toxins which have multiple roles in staphylococcal virulence. To gain an insight into which specific factors are important in PSM-mediated cell membrane disruption, the lytic activity of individual PSM peptides against phospholipid vesicles and T cells was investigated. Vesicles were most susceptible to lysis by the PSMα subclass of peptides (α1-3 in particular), when containing between 10 and 30mol% cholesterol, which for these vesicles is the mixed solid ordered (so)-liquid ordered (lo) phase. Our results show that the PSMβ class of peptides has little effect on vesicles at concentrations comparable to that of the PSMα class and exhibited no cytotoxicity. Furthermore, within the PSMα class, differences emerged with PSMα4 showing decreased vesicle and cytotoxic activity in comparison to its counterparts, in contrast to previous studies. In order to understand this, peptides were studied using helical wheel projections and circular dichroism measurements. The degree of amphipathicity, alpha-helicity and properties such as charge and hydrophobicity were calculated, allowing a structure-function relationship to be inferred. The degree of alpha-helicity of the peptides was the single most important property of the seven peptides studied in predicting their lytic activity. These results help to redefine this class of peptide toxins and also highlight certain membrane parameters required for efficient lysis.

  19. Investigation of relationships between parameters of solar nano-flares and solar activity

    NASA Astrophysics Data System (ADS)

    Safari, Hossein; Javaherian, Mohsen; Kaki, Bardia

    2016-07-01

    Solar flares are one of the important coronal events which are originated in solar magnetic activity. They release lots of energy during the interstellar medium, right after the trigger. Flare prediction can play main role in avoiding eventual damages on the Earth. Here, to interpret solar large-scale events (e.g., flares), we investigate relationships between small-scale events (nano-flares) and large-scale events (e.g., flares). In our method, by using simulations of nano-flares based on Monte Carlo method, the intensity time series of nano-flares are simulated. Then, the solar full disk images taken at 171 angstrom recorded by SDO/AIA are employed. Some parts of the solar disk (quiet Sun (QS), coronal holes (CHs), and active regions (ARs)) are cropped and the time series of these regions are extracted. To compare the simulated intensity time series of nano-flares with the intensity time series of real data extracted from different parts of the Sun, the artificial neural networks is employed. Therefore, we are able to extract physical parameters of nano-flares like both kick and decay rate lifetime, and the power of their power-law distributions. The procedure of variations in the power value of power-law distributions within QS, CH is similar to AR. Thus, by observing the small part of the Sun, we can follow the procedure of solar activity.

  20. Investigation of two o-hydroxy Schiff bases in terms of prototropy and radical scavenging activity

    NASA Astrophysics Data System (ADS)

    Albayrak Kaştaş, Çiğdem; Kaştaş, Gökhan; Güder, Aytaç; Gür, Mahmut; Muğlu, Halit; Büyükgüngör, Orhan

    2017-02-01

    Two Schiff bases, namely (E)-4,6-dibromo-3-methoxy-2-[(phenylimino)methyl]phenol (1) and (Z)-2,4-dibromo-6-[(4-buthylphenylamino)methylene]-5-methoxycyclohexa-2,4-dienone (2), have been investigated by considering solvent, substituent and temperature dependence of prototropy, and scavenging activities. Experimental (X-ray diffraction, UV-vis and NMR) and computational (DFT) techniques have been used to obtain key data on prototropy and other properties of interest. X-ray and UV-vis results underline the variability in the structural preferences of the compounds with respect to the phase and solvent media conditions. This kind of tautomeric behavior has been elaborated by 1H NMR and 13C NMR experiments performed at room and low temperatures. Radical scavenging properties of two compounds have been probed for their usage potentials as therapeutic agent and ingredient in medicinal and food industries, respectively. For this purpose, three different test methods (DPPH, ABTS•+ and DMPD•+) have been used. It has been found from in vivo and in vitro studies that the compound 2 could be interesting as an active component in pharmaceutical industry or as an additive in food industry when its antiradical activity is considered.

  1. Investigation of Prolactin Receptor Activation and Blockade Using Time-Resolved Fluorescence Resonance Energy Transfer

    PubMed Central

    Tallet, Estelle; Fernandez, Isabelle; Zhang, Chi; Salsac, Marion; Gregor, Nathalie; Ayoub, Mohammed Akli; Pin, Jean Philippe; Trinquet, Eric; Goffin, Vincent

    2011-01-01

    The prolactin receptor (PRLR) is emerging as a therapeutic target in oncology. Knowledge-based drug design led to the development of a pure PRLR antagonist (Del1-9-G129R-hPRL) that was recently shown to prevent PRL-induced mouse prostate tumorogenesis. In humans, the first gain-of-function mutation of the PRLR (PRLRI146L) was recently identified in breast tumor patients. At the molecular level, the actual mechanism of action of these two novel players in the PRL system remains elusive. In this study, we addressed whether constitutive PRLR activation (PRLRI146L) or PRLR blockade (antagonist) involved alteration of receptor oligomerization and/or of inter-chain distances compared to unstimulated and PRL-stimulated PRLR. Using a combination of various biochemical and spectroscopic approaches (co-IP, blue native electrophoresis, BRET1), we demonstrated that preformed PRLR homodimers are altered neither by PRL- or I146L-induced receptor triggering, nor by antagonist-mediated blockade. These findings were confirmed using a novel time-resolved fluorescence resonance energy transfer (TR-FRET) technology that allows monitoring distance changes between cell surface tagged receptors. This technology revealed that PRLR blockade or activation did not involve detectable distance changes between extracellular domains of receptor chains within the dimer. This study merges with our previous structural investigations suggesting that the mechanism of PRLR activation solely involves intermolecular contact adaptations leading to subtle intramolecular rearrangements. PMID:22649370

  2. Investigation of the activity level and radiological impacts of naturally occurring radionuclides in blast furnace slag.

    PubMed

    Uğur, F A; Turhan, S; Sahan, H; Sahan, M; Gören, E; Gezer, F; Yeğingil, Z

    2013-01-01

    The activity level and possible radiological impacts of naturally occurring radionuclides on the health of workers and members of the public, as a result of utilisation of blast furnace slag (BFS) samples as a substitute for aggregate in road construction were investigated by using a gamma-ray spectrometer and potential exposure scenarios given in Radiation Protection 122. The mean activity concentrations of the (226)Ra, (232)Th and (40)K in BFS samples were found to be 152.4, 54.9 and 183.1 Bq kg(-1), respectively. These values are compared with typical values measured in BFS samples from the European Union countries, which are 270, 70 and 240 Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. The values of radium equivalent activity index calculated for BFS samples were within the recommended safety limits. The highest total annual effective doses evaluated as 0.9 and 0.4 mSv y(-1) for members of the public and workers, respectively, were lower than the annual limit of 1 mSv y(-1).

  3. Candida rugosa lipase immobilization on hydrophilic charged gold nanoparticles as promising biocatalysts: Activity and stability investigations.

    PubMed

    Venditti, Iole; Palocci, Cleofe; Chronopoulou, Laura; Fratoddi, Ilaria; Fontana, Laura; Diociaiuti, Marco; Russo, Maria Vittoria

    2015-07-01

    In this work, a simple and versatile methodology to obtain two different bioconjugated systems has been developed by the immobilization of Candida rugosa lipase (CRL) on hydrophilic gold nanoparticles functionalized with 2-diethylaminoethanethiol hydrochloride (DEA) or with sodium 3-mercapto-1-propanesulfonate (3MPS), namely Au-DEA@CRL and Au-3MPS@CRL. Both spectroscopic and morphological properties of metal nanoparticles have been deeply investigated. The enzyme loading and lipolytic activity of AuNPs@CRL bioconjugates have been studied with respect to different surface functionalization and compared with the free enzyme. Some physical and chemical parameters had a strong effect on enzyme activity and stability, that were improved in the case of the Au-DEA@CRL bioconjugate, which showed a remarkable biocatalytic performance (95% of residual lipolytic activity compared with free CRL) and stability in experimental conditions concerning pH (range 5-8) and temperature (range 20-60°C), as often required for the industrial scale up of catalytic systems.

  4. Investigating activity of masticatory muscles in patients with hypermobile temporomandibular joints by using EMG

    PubMed Central

    Davoudi, Amin; Rybalov, Oleg; Shadmehr, Elham; Hatami, Amin

    2015-01-01

    Background Temporomandibular joint hypermobility (TMJH) can manifest higher range of motions in mandible. The aim of this study was to investigate and compare the activity of masticatory muscle of TMJs in healthy individuals and patients with mild, moderate and severe TMJH. Material and Methods In this clinical study, 69 patients (between the ages of 22 to 42) with manifestation of TMJH were included. The patients were divided into three groups based on their maximum mouth opening (MMO): (light) with MMO of 50-55 mm; (moderate) with MMO between 55 to 65 mm; and (severe) with MMO >65 mm. Also, 20 healthy people with profiled tomography in the last 6 months were invited as control group (healthy) with normal MMO (<50 mm). All the groups subjected to electromyogram (EMG) in 2 steps: maximal voluntary clenching (MVC) of the jaws; and during chewing of bread by using one side of the jaws voluntary. The collected data were analyzed by Student T-test and Chi-Square tests using SPSS software version 15 at significant level of 0.05. Results Both TMJs of light, moderate and severe groups showed significant differences in frequency, time of activity and rest in comparison with healthy group during chewing and MVC (all p values < 0.01). Conclusions Masticatory muscles activity reduced in relation with the severity of TMJH and higher excessive mouth opening. Key words:Electromyography, joint hypermobility, mouth opening, tempormandibular joint. PMID:26155352

  5. Trait anxiety impact on posterior activation asymmetries at rest and during evoked negative emotions: EEG investigation.

    PubMed

    Aftanas, Ljubomir I; Pavlov, Sergey V

    2005-01-01

    The main objective of the present investigation was to examine how high trait anxiety would influence cortical EEG asymmetries under non-emotional conditions and while experiencing negative emotions. The 62-channel EEG was recorded in control (n=21) and high anxiety (HA, n=18) non-patient individuals. Results showed that in HA subjects, the lowest level of arousal (eyes closed) was associated with stronger right-sided parieto-temporal theta-1 (4-6 Hz) and beta-1 (12-18 Hz) activity, whereas increased non-emotional arousal (eyes open, viewing neutral movie clip) was marked by persisting favored right hemisphere beta-1 activity. In turn, viewing aversive movie clip by the HA group led to significant lateralized decrease of the right parieto-temporal beta-1 power, which was initially higher in the emotionally neutral conditions. The EEG data suggests that asymmetrical parieto-temporal theta-1 and beta-1 EEG activity might be better interpreted in terms of Gray's BAS and BIS theory.

  6. Activity.

    ERIC Educational Resources Information Center

    Clearing: Nature and Learning in the Pacific Northwest, 1984

    1984-01-01

    Presents three activities: (1) investigating succession in a schoolground; (2) investigating oak galls; and (3) making sun prints (photographs made without camera or darkroom). Each activity includes a list of materials needed and procedures used. (JN)

  7. Investigation of the possible protective role of gallic acid on paraoxanase and arylesterase activities in livers of rats with acute alcohol intoxication.

    PubMed

    Kartkaya, Kazim; Oğlakçi, Ayşegül; Şentürk, Hakan; Bayramoğlu, Gökhan; Canbek, Mediha; Kanbak, Güngör

    2013-04-01

    Gallic acid, a polyphenyl class natural product from gallnut and green tea, is known to be antioxidant, anti-inflammatory and radical scavenger. In this study, we aimed to investigate the possible protective effects of gallic acid on paraoxonase and arylesterase activities in liver exposed to acute alcohol intoxication. Paraoxonase and arylesterase activities in liver tissue and serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were measured. Histological investigations were also made. In our study, we observed a significant increase of serum alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase activities, which are indicators of liver damage after acute ethanol consumption. Gallic acid therapy has significantly reduced the increase in these biomarkers, indicating a possible hepatoprotective effect of gallic acid. Ethanol consumption caused a significant decrease in liver paraoxonase activity (P < 0.001). Gallic acid treatment partly restored this decreased paraoxonase activity, which resulted from ethanol administration. A gallic acid dose of 100 mg/kg was observed as highest restoring effect for paraoxonase activity (P < 0.05). The activity of arylesterase was decreased in the ethanol group as compared with the control group, but this was not significant. However, 50 mg/kg of gallic acid treatment restored the loss of this activity due to ethanol exposure (P < 0.001). We observed that gallic acid ameliorates the liver damage caused by excessive alcohol consumption in a dose-dependent way. Our results in this study showed that gallic acid might have a protective effect against alcoholic liver disease.

  8. Enhanced susceptibility of photosynthesis to low-temperature photoinhibition due to interruption of chill-induced increase of S-adenosylmethionine decarboxylase activity in leaves of spinach (Spinacia oleracea L.).

    PubMed

    He, Lixiong; Nada, Kazuyoshi; Kasukabe, Yoshihisa; Tachibana, Shoji

    2002-02-01

    The possible involvement of polyamines in the chilling tolerance of spinach (Spinacia oleracea L.) was investigated focusing on photosynthesis. During chilling at 8/5C (day/night) for 6 d, S-adenosylmethionine decarboxylase (SAMDC) activity increased significantly in leaves in parallel with the increase in putrescine and spermidine (Spd) content in leaves and chloroplasts. Treatment of leaves with methylglyoxal-bis(guanylhydrazone) (MGBG), an SAMDC inhibitor, resulted in the deterioration of plant growth and photosynthesis under chilling conditions, which was reversed by the concomitant treatment with Spd through the roots. Plants treated with MGBG showed lower photochemical efficiency of PSII than either the control or plants treated with MGBG plus Spd during chilling and even after transfer to warm conditions, suggesting an increase of photoinhibition due to low Spd in chloroplasts. Indeed, MGBG-treated plants had much lower activities of thylakoid electron transport and enzymes in carbon metabolism as well as higher degrees of lipid peroxidation of thylakoid membranes compared to the control. These results indicate that the enhanced activity of SAMDC with a consequential rise of Spd in chloroplasts is crucial for the cold acclimation of the photosynthetic apparatus in spinach leaves.

  9. Investigating correlation of lighting activity and precipitation in an Eastern Mediterranean island

    NASA Astrophysics Data System (ADS)

    Iordanidou, Vasiliki; Koutroulis, Aristeidis; Tsanis, Ioannis

    2015-04-01

    This study examines conditions under which lightning activity and precipitation events can be correlated in an Eastern Mediterranean island climate. As a first step, the activity within a predefined area of 50km radius around the gauge station is examined, given the temporal evolution of rain accumulation at an hourly time step. Then the lightning activity is grouped in time-space clusters and for each lightning-cluster precipitation recordings of 10 minutes time step from nearby gauges are searched in an area of variable radius ranging from 10 to 100km. The number of clusters is decided according to the g-means algorithm in which the number of clusters is increasing until the data of all clusters follow the Gaussian distribution. For different durations, number of lightning events and radius the proportion of the corresponding precipitation events for the given radius around the lightning-clusters is investigated. The methods are tested in the case study of the island of Crete. Precipitation data from 22 gauging stations over Crete and lightning data from the Global Lightning Network (GLN) are examined for the investigation of possible associations in a period of almost two years (09/2012-07/2014). For the first approach, for half of the stations rain accumulations over 10mm/h (90th percentile of rain) are recorded up to a day after lightning activity occurrence. According to the second approach, lightning-clusters of smaller duration (up to 5 hours) and more lightning flashes (more than 100) are highly associated with rain events. The optimal radius from the center of the lightning-cluster, according to the proportion of rain events, is found to be 30km. The results establish a better understanding of the relations between lightning and precipitation and could provide valuable information to the now-casting of flash flood events triggered by severe thunderstorms. The research reported in this study effort was fully supported by the "ARISTEIA II" Action

  10. SU-E-T-231: Measurements of Gold Nanoparticle-Mediated Proton Dose Enhancement Due to Particle-Induced X-Ray Emission and Activation Products Using Radiochromic Films and CdTe Detector

    SciTech Connect

    Cho, J; Cho, S; Manohar, N; Krishnan, S

    2014-06-01

    Purpose: There have been several reports of enhanced cell-killing and tumor regression when tumor cells and mouse tumors were loaded with gold nanoparticles (GNPs) prior to proton irradiation. While particle-induced xray emission (PIXE), Auger electrons, secondary electrons, free radicals, and biological effects have been suggested as potential mechanisms responsible for the observed GNP-mediated dose enhancement/radiosensitization, there is a lack of quantitative analysis regarding the contribution from each mechanism. Here, we report our experimental effort to quantify some of these effects. Methods: 5-cm-long cylindrical plastic vials were filled with 1.8 mL of either water or water mixed with cylindrical GNPs at the same gold concentration (0.3 mg Au/g) as used in previous animal studies. A piece of EBT2 radiochromic film (30-µm active-layer sandwiched between 80/175-µm outer-layers) was inserted along the long axis of each vial and used to measure dose enhancement due to PIXE from GNPs. Vials were placed at center-of-modulation (COM) and 3-cm up-/down-stream from COM and irradiated with 5 different doses (2–10 Gy) using 10-cm-SOBP 160-MeV protons. After irradiation, films were cleaned and read to determine the delivered dose. A vial containing spherical GNPs (20 mg Au/g) was also irradiated, and gamma-rays from activation products were measured using a cadmium-telluride (CdTe) detector. Results: Film measurements showed no significant dose enhancement beyond the experimental uncertainty (∼2%). There was a detectable activation product from GNPs, but it appeared to contribute to dose enhancement minimally (<0.01%). Conclusion: Considering the composition of EBT2 film, it can be inferred that gold characteristic x-rays from PIXE and their secondary electrons make insignificant contribution to dose enhancement. The current investigation also suggests negligible dose enhancement due to activation products. Thus, previously-reported GNP-mediated proton dose

  11. Experimental Investigation of Active Feedback Control of Turbulent Transport in a Magnetized Plasma

    SciTech Connect

    Gilmore, Mark Allen

    2013-07-07

    A new and unique basic plasma science laboratory device - the HelCat device (HELicon-CAThode) - has been constructed and is operating at the University of New Mexico. HelCat is a 4 m long, 0.5 m diameter device, with magnetic field up to 2.2 kG, that has two independent plasmas sources - an RF helicon source, and a thermionic cathode. These two sources, which can operate independently or simultaneously, are capable of producing plasmas with a wide range of parameters and turbulence characteristics, well suited to a variety of basic plasma physics experiments. An extensive set of plasma diagnostics is also operating. Experiments investigating the active feedback control of turbulent transport of particles and heat via electrode biasing to affect plasma ExB flows are underway, and ongoing.

  12. Investigating the capacity of self and peer assessment activities to engage students and promote learning

    NASA Astrophysics Data System (ADS)

    Willey, Keith; Gardner, Anne

    2010-08-01

    The authors have previously reported the effectiveness of using self and peer assessment to improve learning outcomes by providing opportunities to practise, assess and provide feedback on students' attribute development. Despite this work and the research of others, a significant number of students and, indeed, many academics focus on the free-rider deterrent capability of self and peer assessment, rather than its capacity to provide opportunities for developing judgement and facilitating reflection and feedback to complete the learning cycle. The advent of web-based tools such as SPARKPLUS allows the frequent and efficient implementation of self and peer assessment activities even in large classes. This article reports the results of an investigation into whether the regular use of self and peer assessment in different contexts promoted effective peer learning, increased engagement and encouraged students to learn.

  13. Thiaminase activity and life history investigations in American Shad in the Columbia river

    USGS Publications Warehouse

    Wetzel, Lisa A.; Parsley, Michael J; van der Leeuw, Bjorn K.; Larsen, Kimberly A.

    2011-01-01

    American shad Alosa sapidissima fry were successfully transplanted from the Atlantic to the Pacific coast in 1871 and have subsequently proliferated. The Columbia River population is in the millions, yet few investigations have been conducted to better understand their life history, population dynamics, or potential impacts on other species. In 2007 and 2008 we captured American shad from the Columbia River to assess levels of thiaminase activity and to characterize some aspects of American shad life history. Thiaminase levels in age-0 and adult fish were high and ranged from 4,113-20,874 pmol/g/min. Ages of spawning American shad ranged from 3-7 years and iteroparity was approximately 33-36% in the spawning population. Males were typically younger and smaller and had a higher degree of iteroparity than females

  14. A bullet fired in dry water: an investigative activity to learn hydrodynamics concepts

    NASA Astrophysics Data System (ADS)

    Azevedo Leitão, Ulisses; dos Anjos Pinheiro da Silva, Antonio; Trindade do Nascimento, Natália Cristina; Mara Benedita da Cruz Gervásio, Lilian

    2017-01-01

    In this paper we report an investigative activity on hydrodynamics, in the context of an inquiry-based learning project. The aim is to analyse the experiment of a bullet shot underwater. Using Tracker, a video analysing and modelling software, the displacement of the bullet was measured as function of time, processing a slow motion video from YouTube. It was found that the displacement of the bullet is well described in the first 20 ms by the inviscid flow regime, where the Newtonian drag force overcomes the viscous drag. This behaviour is discussed in the context of what Richard Feynman’s famous Lectures on Physics describes as ‘The Flow of Dry Water’.

  15. Investigation of activity and stability of papain by adsorption on multi-wall carbon nanotubes.

    PubMed

    Homaei, Ahmad; Samari, Fayezeh

    2017-02-14

    Papain was non-covalently immobilized on multi-walled carbon nanotubes (MWCNTs). Its stabilities and catalytic activity for casein degradation were comprehensively investigated. Compared to free papain, the nano-enzyme exhibited significantly improved thermal, pH and recycling stability. Comparisons of the kinetic parameters between free papain and the heterogeneous enzyme revealed that the Km value of the immobilized papain experienced a slight increase, which suggested that the MWCNTs did not significantly hinder papain's access to substrate or release of product. This feature is beneficial to the industrial applications because of its potential to be easily separated from the end product at the end of the reaction, reuse for multiple times and allow the development of multiple enzyme reaction system.

  16. Investigation of therapeutic potentials of some selected medicinal plants using neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Abubakar, Sani; Usman, Ahmed Rufa'i.; Isa, Nasiru Fage; Khandaker, Mayeen Uddin; Abubakar, Nuraddeen

    2015-04-01

    Series of attempts were made to investigate concentrations of trace elements and their therapeutic properties in various medicinal plants. In this study, samples of some commonly used plants were collected from Bauchi State, Nigeria. They includes leaves of azadirachta indica (neem), Moringa Oleifera (moringa), jatropha curcas (purgin Nut), guiera senegalensis (custard apple) and anogeissus leiocarpus (African birch). These samples were analyzed for their trace elements contents with both short and long irradiation protocols of Instrumental Neutron Activation Analysis (INAA) at Nigerian Research Reactor-1 (NIRR-1) of Ahmadu Bello University, Zaria, Nigeria. The level of trace elements found varies from one sample to another, with some reported at hundreds of mg/Kg dry weight. The results have been compared with the available literature data. The presence of these trace elements indicates promising potentials of these plants for relief of certain ailments.

  17. Investigation of therapeutic potentials of some selected medicinal plants using neutron activation analysis

    SciTech Connect

    Abubakar, Sani; Isa, Nasiru Fage; Usman, Ahmed Rufa’i; Khandaker, Mayeen Uddin; Abubakar, Nuraddeen

    2015-04-24

    Series of attempts were made to investigate concentrations of trace elements and their therapeutic properties in various medicinal plants. In this study, samples of some commonly used plants were collected from Bauchi State, Nigeria. They includes leaves of azadirachta indica (neem), Moringa Oleifera (moringa), jatropha curcas (purgin Nut), guiera senegalensis (custard apple) and anogeissus leiocarpus (African birch). These samples were analyzed for their trace elements contents with both short and long irradiation protocols of Instrumental Neutron Activation Analysis (INAA) at Nigerian Research Reactor-1 (NIRR-1) of Ahmadu Bello University, Zaria, Nigeria. The level of trace elements found varies from one sample to another, with some reported at hundreds of mg/Kg dry weight. The results have been compared with the available literature data. The presence of these trace elements indicates promising potentials of these plants for relief of certain ailments.

  18. Investigation of Water-Soluble X-ray Luminescence Nanoparticles for Photodynamic Activation

    SciTech Connect

    Liu, Yuanfang; Chen, Wei; Wang, Shaopeng; Joly, Alan G.

    2008-01-28

    In this letter, we report the synthesis of LaF3:Tb3+-MTCP (meso-Tetra(4-carboxyphenyl) porphine) nanoparticle conjugates and investigate the energy transfer as well as singlet oxygen generation following X-ray irradiation. Our observations indicate that LaF3:Tb3+-MTCP nanoparticle conjugates are efficient photodynamic agents that can be initiated by X-rays at a reasonably low dose. The addition of folic acid to facilitate targeting to folate receptors on tumor cells has no effect on the quantum yield of singlet oxygen in the nanoparticle-MTCP conjugates. Our pilot studies indicate that water-soluble scintillation nanoparticles can be potentially used to activate photodynamic therapy as a promising deep cancer treatment.

  19. Quantitative-spatial assessment of soil contamination in S. Francisco de Assis due to mining activity of the Panasqueira mine (Portugal).

    PubMed

    Ferreira da Silva, Eduardo; Freire Ávila, Paula; Salgueiro, Ana Rita; Candeias, Carla; Garcia Pereira, Henrique

    2013-11-01

    Through the years, mining and beneficiation processes produces large amounts of As-rich mine wastes laid up in huge tailings and open-air impoundments (Barroca Grande and Rio tailings) that are the main source of pollution in the surrounding area once they are exposed to the weathering conditions leading to the formation of AMD and consequently to the contamination of the surrounding environments, in particularly soils. In order to investigate the environmental contamination impact on S. Francisco de Assis (village located between the two major impoundments and tailings) agricultural soils, a geochemical survey was undertaken to assess toxic metals associations, related levels and their spatial distribution, and to identify the possible contamination sources. According to the calculated contamination factor, As and Zn have a very high contamination factor giving rise to 65.4% of samples with a moderate to high pollution degree; 34.6% have been classified as nil to very low pollution degree. The contamination factor spatial distribution put in evidence the fact that As, Cd, Cu, Pb, and Zn soils contents, downstream Barroca Grande tailing, are increased when compared with the local Bk soils. The mechanical dispersion, due to erosion, is the main contamination source. The chemical extraction demonstrates that the trace metals distribution and accumulation in S. Francisco de Assis soils is related to sulfides, but also to amorphous or poorly crystalline iron oxide phases. The partitioning study allowed understanding the local chemical elements mobility and precipitation processes, giving rise to the contamination dispersion model of the study area. The wind and hydrological factors are responsible for the chemical elements transport mechanisms, the water being the main transporter medium and soils as one of the possible retention media.

  20. Importance of penicillinase production for activity of penicillin alone or in combination with sulbactam in experimental endocarditis due to methicillin-resistant Staphylococcus aureus.

    PubMed Central

    Fantin, B; Pierre, J; Castéla-Papin, N; Saint-Julien, L; Drugeon, H; Farinotti, R; Carbon, C

    1996-01-01

    The activity of penicillin, alone and in combination with sulbactam, against a heterogeneously methicillin-resistant, penicillinase-producing clinical isolate of Staphylococcus aureus and its penicillinase-negative derivative was investigated in vitro and in a rabbit experimental endocarditis model. Penicillin was significantly more effective than vancomycin against the penicillinase-negative derivative in vivo (P < 0.001), and it sterilized 25% of the vegetations. The combination of penicillin and sulbactam exhibited an in vivo synergistic effect on the penicillinase-producing strain (P < 0.01) but did not produce any advantage over treatment with vancomycin, even when a high dose of sulbactam was used (100 mg/kg of body weight every 6 h). This combination was significantly less effective against the penicillinase-producing strain than was penicillin alone against the penicillinase-negative derivative (P < 0.03). In addition, the most resistant subpopulation of the surviving bacteria, which grew on agar containing 16 micrograms of methicillin per ml, was detected in 5 of 6 animals treated with penicillin and a high dose of sulbactam against the penicillinase-producing strain compared with only 1 of 12 animals treated with penicillin alone against the penicillinase-negative derivative (P < 0.01). We conclude that penicillin is highly effective against penicillinase-negative methicillin-resistant S. aureus and that penicillinase production, rather than methicillin resistance, appears to be the limiting factor for the activity of the penicillin-sulbactam combination against penicillinase-producing, methicillin-resistant S. aureus. PMID:8723470

  1. INVESTIGATION OF HELICITY AND ENERGY FLUX TRANSPORT IN THREE EMERGING SOLAR ACTIVE REGIONS

    SciTech Connect

    Vemareddy, P.

    2015-06-20

    We report the results of an investigation of helicity and energy flux transport from three emerging solar active regions (ARs). Using time sequence vector magnetic field observations obtained from the Helioseismic Magnetic Imager, the velocity field of plasma flows is derived by the differential affine velocity estimator for vector magnetograms. In three cases, the magnetic fluxes evolve to pump net positive, negative, and mixed-sign helicity flux into the corona. The coronal helicity flux is dominantly coming from the shear term that is related to horizontal flux motions, whereas energy flux is dominantly contributed by the emergence term. The shear helicity flux has a phase delay of 5–14 hr with respect to absolute magnetic flux. The nonlinear curve of coronal energy versus relative helicity identifies the configuration of coronal magnetic fields, which is approximated by a fit of linear force-free fields. The nature of coronal helicity related to the particular pattern of evolving magnetic fluxes at the photosphere has implications for the generation mechanism of two kinds of observed activity in the ARs.

  2. Hardening kinetics investigation of alkali-activated binder by small amplitude oscillatory rheometry

    NASA Astrophysics Data System (ADS)

    Rieger, D.; Kullová, L.; Čekalová, M.; Kovářík, T.

    2017-01-01

    In this study, the rheological behavior of geopolymeric inorganic binder was determined. This binder was synthesized by alkaline activation of mixture, comprising calcined claystone powder and milled blast furnace slag. As an alkaline activator of hardening process, the potassium silicate solution was used. For the investigation of hardening kinetics, the strain controlled small amplitude oscillatory rheometry was used with strain of 0.01%. The reproducibility and versatility of this method is demonstrated for determination of hardening process evolution. The changes of loss tangent shape were studied in this experiment and applied for determination of gelation time. All experiments were conducted at isothermal conditions in temperature range 27-70°C and parallel plate geometry. The results indicate that reaction kinetics is directly depending on temperature. The hardening kinetics was mathematically described and these calculations were compared with self-contained experiment conducted at 2°C. This experiment is described in details and the results of gelation time measurements confirmed calculated data.

  3. Investigation of the Deformation Activation Volume of an Ultrafinegrained Ti50Ni50 Alloy

    NASA Astrophysics Data System (ADS)

    Gunderov, D. V.; Churakova, A. A.; Lukianov, A. V.; Prokofiev, E. A.; Prokoshkin, S. D.; Kreizberg, A. Yu.; Raab, G. I.; Sabirov, I. N.

    2015-10-01

    The mechanical properties, strain rate sensitivity (m) and deformation activation volume (ΔV) are investigated at the experimental temperatures from 20 to 400°C in a Ti50Ni50 alloy in a coarse-grained (CG) state with the austenite grain size D = 200 μm and in an ultrafine-grained (UFG) state with D = 700 μm following an ECAP treatment. It is observed that this treatment improves the yield strength of the alloy compared to its CG-state. The strain rate sensitivity, m, is found to be by a factor of 1.5-2 higher than that of CG-specimens; it increases with the temperature in both states of the material. As the temperature of the material in tension increases up to Т = 150-250°C, parameter ΔV increases to its maximum and with a further growth of the experimental temperature to 400°C, parameter ΔV decreases. The deformation activation volume of the alloy in the UFG-state is by a factor of 2-4 larger than that in the CG-state for the same experimental temperatures.

  4. Investigation into the antioxidant and antidiabetic potential of Moringa stenopetala: identification of the active principles.

    PubMed

    Habtemariam, Solomon

    2015-03-01

    The fresh leaves of Moringa stenopetala (family, Moringaceae) are commonly eaten as cabbage while dried leaves are used as nutritional supplement and for treating a variety of disease conditions including diabetes. The present investigation into the therapeutic potential of the leaves and seeds of the plant revealed no inhibitory effect against α-glucosidase enzyme up to the concentration of 200 μg/mL but the leaves extract displayed potent DPPH (1,1-diphenyl-2- picrylhydrazyl) radical scavenging effect (IC50, 59.5 ± 4.1 μg/mL). An activity directed fractionation and isolation procedure resulted in the identification of the major antioxidant compound as rutin and minor active component, neochlorogenic acid. Both the crude extract (0.8-200 μg/mL) and rutin (0.8-200 μM) but not neochlorogenic acid displayed a concentration-dependent protection of human pancreatic β-cells (1.4E7 cells) from oxidant-induced cell death. The identification of these compounds along with their potential role in the nutritional and medicinal significance of the plant is discussed.

  5. Antioxidant Activity of Magnolol and Honokiol: Kinetic and Mechanistic Investigations of Their Reaction with Peroxyl Radicals.

    PubMed

    Amorati, Riccardo; Zotova, Julija; Baschieri, Andrea; Valgimigli, Luca

    2015-11-06

    Magnolol and honokiol, the bioactive phytochemicals contained in Magnolia officinalis, are uncommon antioxidants bearing isomeric bisphenol cores substituted with allyl functions. We have elucidated the chemistry behind their antioxidant activity by experimental and computational methods. In the inhibited autoxidation of cumene and styrene at 303 K, magnolol trapped four peroxyl radicals, with a kinh of 6.1 × 10(4) M(-1) s(-1) in chlorobenzene and 6.0 × 10(3) M(-1) s(-1) in acetonitrile, and honokiol trapped two peroxyl radicals in chlorobenzene (kinh = 3.8 × 10(4) M(-1) s(-1)) and four peroxyl radicals in acetonitrile (kinh = 9.5 × 10(3) M(-1) s(-1)). Their different behavior arises from a combination of intramolecular hydrogen bonding among the reactive OH groups (in magnolol) and of the OH groups with the aromatic and allyl π-systems, as confirmed by FT-IR spectroscopy and DFT calculations. Comparison with structurally related 3,3',5,5'-tetramethylbiphenyl-4,4'-diol, 2-allylphenol, and 2-allylanisole allowed us to exclude that the antioxidant behavior of magnolol and honokiol is due to the allyl groups. The reaction of the allyl group with a peroxyl radical (C-H hydrogen abstraction) proceeds with rate constant of 1.1 M(-1) s(-1) at 303 K. Magnolol and honokiol radicals do not react with molecular oxygen and produce no superoxide radical under the typical settings of inhibited autoxidations.

  6. Investigation and prediction of protein precipitation by polyethylene glycol using quantitative structure-activity relationship models.

    PubMed

    Hämmerling, Frank; Ladd Effio, Christopher; Andris, Sebastian; Kittelmann, Jörg; Hubbuch, Jürgen

    2017-01-10

    Precipitation of proteins is considered to be an effective purification method for proteins and has proven its potential to replace costly chromatography processes. Besides salts and polyelectrolytes, polymers, such as polyethylene glycol (PEG), are commonly used for precipitation applications under mild conditions. Process development, however, for protein precipitation steps still is based mainly on heuristic approaches and high-throughput experimentation due to a lack of understanding of the underlying mechanisms. In this work we apply quantitative structure-activity relationships (QSARs) to model two parameters, the discontinuity point m* and the β-value, that describe the complete precipitation curve of a protein under defined conditions. The generated QSAR models are sensitive to the protein type, pH, and ionic strength. It was found that the discontinuity point m* is mainly dependent on protein molecular structure properties and electrostatic surface properties, whereas the β-value is influenced by the variance in electrostatics and hydrophobicity on the protein surface. The models for m* and the β-value exhibit a good correlation between observed and predicted data with a coefficient of determination of R(2)≥0.90 and, hence, are able to accurately predict precipitation curves for proteins. The predictive capabilities were demonstrated for a set of combinations of protein type, pH, and ionic strength not included in the generation of the models and good agreement between predicted and experimental data was achieved.

  7. In Vitro Antioxidant versus Metal Ion Chelating Properties of Flavonoids: A Structure-Activity Investigation

    PubMed Central

    Cherrak, Sabri Ahmed; Mokhtari-Soulimane, Nassima; Berroukeche, Farid; Bensenane, Bachir; Cherbonnel, Angéline; Merzouk, Hafida; Elhabiri, Mourad

    2016-01-01

    Natural flavonoids such as quercetin, (+)catechin and rutin as well as four methoxylated derivatives of quercetin used as models were investigated to elucidate their impact on the oxidant and antioxidant status of human red blood cells (RBCs). The impact of these compounds against metal toxicity was studied as well as their antiradical activities with DPPH assay. Antihemolytic experiments were conducted on quercetin, (+)catechin and rutin with excess of Fe, Cu and Zn (400 μM), and the oxidant (malondialdehyde, carbonyl proteins) and antioxidant (reduced glutathione, catalase activity) markers were evaluated. The results showed that Fe and Zn have the highest prooxidant effect (37 and 33% of hemolysis, respectively). Quercetin, rutin and (+)catechin exhibited strong antioxidant properties toward Fe, but this effect was decreased with respect to Zn ions. However, the Cu showed a weak antioxidant effect at the highest flavonoid concentration (200 μM), while a prooxidant effect was observed at the lowest flavonoid concentration (100 μM). These results are in agreement with the physico-chemical and antiradical data which demonstrated that binding of the metal ions (for FeNTA: (+)Catechin, KLFeNTA = 1.6(1) × 106 M-1 > Rutin, KLFeNTA = 2.0(9) × 105 M-1 > Quercetin, KLFeNTA = 1.0(7) × 105 M-1 > Q35OH, KLFeNTA = 6.3(8.7) × 104 M-1 > Quercetin3’4’OH and Quercetin 3OH, KLFeNTA ~ 2 × 104 M-1) reflects the (anti)oxidant status of the RBCs. This study reveals that flavonoids have both prooxidant and antioxidant activity depending on the nature and concentration of the flavonoids and metal ions. PMID:27788249

  8. Investigating the Nuclear Activity of Barred Spiral Galaxies: The Case of NGC 1672

    NASA Technical Reports Server (NTRS)

    Jenkins, L. P.; Brandt, W. N.; Colbert, E. J.; Koribalski, B.; Kuntz, K. D.; Levan, A. J.; Ojha, R.; Roberts, T. P.; Ward, M. J.; Zezas, A.

    2011-01-01

    We have performed an X-ray study of the nearby barred spiral galaxy NGC 1672, primarily to ascertain the effect of the bar on its nuclear activity. We use both Chandra and XMM-Newton observations to investigate its X-ray properties, together with supporting high-resolution optical imaging data from the Hubble Space Telescope (HST) infrared imaging from the Spitzer Space Telescope, and Australia Telescope Compact Array ground-based radio data. We detect 28 X-ray sources within the D25 area of the galaxy; many are spatially correlated with star formation in the bar and spiral arms, and two are identified as background galaxies in the HST images. Nine of the X-ray sources are ultraluminous X-ray sources, with the three brightest (LX 5 * 10(exp 39) erg s(exp -1)) located at the ends of the bar. With the spatial resolution of Chandra, we are able to show for the first time that NGC 1672 possesses a hard (1.5) nuclear X-ray source with a 2-10 keV luminosity of 4 * 10(exp 38) erg s(exp -1). This is surrounded by an X-ray-bright circumnuclear star-forming ring, comprised of point sources and hot gas, which dominates the 2-10 keV emission in the central region of the galaxy. The spatially resolved multiwavelength photometry indicates that the nuclear source is a low-luminosity active galactic nucleus (LLAGN), but with star formation activity close to the central black hole. A high-resolution multiwavelength survey is required to fully assess the impact of both large-scale bars and smaller-scale phenomena such as nuclear bars, rings, and nuclear spirals on the fueling of LLAGN.

  9. The in vitro pharmacological activities and a chemical investigation of three South African Salvia species.

    PubMed

    Kamatou, G P P; Viljoen, A M; Gono-Bwalya, A B; van Zyl, R L; van Vuuren, S F; Lourens, A C U; Başer, K H C; Demirci, B; Lindsey, K L; van Staden, J; Steenkamp, P

    2005-12-01

    Salvia species (sage) are well known in folk medicine throughout the world. In South Africa sage is used against fever and digestive disorders. Three closely related South African species (Salvia stenophylla, Salvia repens and Salvia runcinata) were investigated for their anti-oxidant (DPPH assay); anti-inflammatory (5-lipoxygenase and cyclo-oxygenase assays); antimalarial (tritiated hypoxanthine incorporation assay); antimicrobial (disc diffusion and micro-dilution assays) properties and toxicity profile (tetrazolium-based assay). The solvent extracts exhibited anti-oxidant, antimalarial and antibacterial and poor anti-inflammatory properties. The essential oils exhibited anti-inflammatory and antimalarial properties, but displayed poor anti-oxidant and antimicrobial activity. The extract of Salviastenophylla and the essential oil of Salvia runcinata displayed the highest toxicity profile. Overall, Salvia runcinata displayed the most favorable activity of all three taxa tested with an IC(50) value of 6.09 (anti-oxidant); 29.05 (antimalarial) and 22.82 microg/ml (anti-inflammatory). Analytical procedures (GC-MS and HPLC-UV) were employed to generate chromatographic profiles for the essential oils and solvent extracts respectively. The HPLC analysis revealed the presence of rosmarinic acid in all three taxa while carnosic acid was only present in Salvia repens and Salvia stenophylla. The GC-MS analysis showed that oils were qualitatively and quantitatively variable. beta-Caryophyllene was present in large amounts in all three taxa. Other components present include camphor, alpha-pinene and alpha-bisabolol. The results of the in vitro pharmacological activities provide a scientific basis to validate the use of these Salvia species in traditional medicine in South Africa.

  10. In Vitro Antioxidant versus Metal Ion Chelating Properties of Flavonoids: A Structure-Activity Investigation.

    PubMed

    Cherrak, Sabri Ahmed; Mokhtari-Soulimane, Nassima; Berroukeche, Farid; Bensenane, Bachir; Cherbonnel, Angéline; Merzouk, Hafida; Elhabiri, Mourad

    2016-01-01

    Natural flavonoids such as quercetin, (+)catechin and rutin as well as four methoxylated derivatives of quercetin used as models were investigated to elucidate their impact on the oxidant and antioxidant status of human red blood cells (RBCs). The impact of these compounds against metal toxicity was studied as well as their antiradical activities with DPPH assay. Antihemolytic experiments were conducted on quercetin, (+)catechin and rutin with excess of Fe, Cu and Zn (400 μM), and the oxidant (malondialdehyde, carbonyl proteins) and antioxidant (reduced glutathione, catalase activity) markers were evaluated. The results showed that Fe and Zn have the highest prooxidant effect (37 and 33% of hemolysis, respectively). Quercetin, rutin and (+)catechin exhibited strong antioxidant properties toward Fe, but this effect was decreased with respect to Zn ions. However, the Cu showed a weak antioxidant effect at the highest flavonoid concentration (200 μM), while a prooxidant effect was observed at the lowest flavonoid concentration (100 μM). These results are in agreement with the physico-chemical and antiradical data which demonstrated that binding of the metal ions (for FeNTA: (+)Catechin, KLFeNTA = 1.6(1) × 106 M-1 > Rutin, KLFeNTA = 2.0(9) × 105 M-1 > Quercetin, KLFeNTA = 1.0(7) × 105 M-1 > Q35OH, KLFeNTA = 6.3(8.7) × 104 M-1 > Quercetin3'4'OH and Quercetin 3OH, KLFeNTA ~ 2 × 104 M-1) reflects the (anti)oxidant status of the RBCs. This study reveals that flavonoids have both prooxidant and antioxidant activity depending on the nature and concentration of the flavonoids and metal ions.

  11. Stem girdling evidences a trade-off between cambial activity and sprouting and dramatically reduces plant transpiration due to feedback inhibition of photosynthesis and hormone signaling

    PubMed Central

    López, Rosana; Brossa, Ricard; Gil, Luis; Pita, Pilar

    2015-01-01

    The photosynthesis source–sink relationship in young Pinus canariensis seedlings was modified by stem girdling to investigate sprouting and cambial activity, feedback inhibition of photosynthesis, and stem and root hydraulic capacity. Removal of bark tissue showed a trade-off between sprouting and diameter growth. Above the girdle, growth was accelerated but the number of sprouts was almost negligible, whereas below the girdle the response was reversed. Girdling resulted in a sharp decrease in whole plant transpiration and root hydraulic conductance. The reduction of leaf area after girdling was strengthened by the high levels of abscisic acid found in buds which pointed to stronger bud dormancy, preventing a new needle flush. Accumulation of sugars in leaves led to a coordinated reduction in net photosynthesis (AN) and stomatal conductance (gS) in the short term, but later (gS below 0.07 mol m-2 s-1) AN decreased faster. The decrease in maximal efficiency of photosystem II (FV/FM) and the operating quantum efficiency of photosystem II (ΦPSII) in girdled plants could suggest photoprotection of leaves, as shown by the vigorous recovery of AN and ΦPSII after reconnection of the phloem. Stem girdling did not affect xylem embolism but increased stem hydraulic conductance above the girdle. This study shows that stem girdling affects not only the carbon balance, but also the water status of the plant. PMID:25972884

  12. Mixing tests: diagnostic aides in the investigation of prolonged prothrombin times and activated partial thromboplastin times.

    PubMed

    Kershaw, Geoffrey; Orellana, Daniel

    2013-04-01

    Mixing tests are a relatively simple procedure used in the hemostasis laboratory as a first-line investigation into the cause of an abnormal screening test, typically a prolonged activated partial thromboplastin time and/or a prolonged prothrombin time. The mixing test involves combining the test plasma with normal plasma, then repeating the screening test on the mixture to assess whether the clotting time becomes normal or remains prolonged. The primary purpose of a mixing test is to guide further investigations. When mixing test results "normalize," this suggests the test plasma is deficient in clotting factor(s) and thus specific factor assays can be performed to determine which are reduced. When the mixing test result does not "normalize," this suggests the presence of an inhibitor or other type of interference (e.g., the presence of an anticoagulant such as high-dose heparinoids), and so the laboratory needs to determine if this is a lupus anticoagulant or a specific coagulation factor inhibitor, or another type of inhibitor. Because these follow-up investigations are more costly and time-consuming than the basic screening tests, the appropriate performance and interpretation of mixing tests is advantageous for the laboratory. Moreover, the correct laboratory approach is also clinically relevant, as patient management is ultimately affected, and an incorrect interpretation may lead to inappropriate therapies being established. Components of a mixing test that can influence result interpretation include the sensitivity of the used screening reagents to various factor deficiencies and inhibitors, the source or composition of the normal plasma, and the setting of cutoffs for the formula used in expressing mixing test results. Numerous and differing criteria for mixing test interpretation have been suggested historically, which can lead to confusion as to which approach is the most appropriate. The use of differing criteria will also lead to differing

  13. Experimental investigation of an actively controlled three-dimensional turret wake

    NASA Astrophysics Data System (ADS)

    Shea, Patrick R.

    Hemispherical turrets are bluff bodies commonly used to house optical systems on airborne platforms. These bluff bodies develop complex, three-dimensional flow fields that introduce high mean and fluctuating loads to the turret as well as the airframe support structure which reduce the performance of both the optical systems and the aircraft. An experimental investigation of the wake of a three-dimensional, non-conformal turret was performed in a low-speed wind tunnel at Syracuse University to develop a better understanding of the fundamental flow physics associated with the turret wake. The flow field was studied at a diameter based Reynolds number of 550,000 using stereoscopic particle image velocimetry and dynamic pressure measurements both with and without active flow control. Pressure measurements were simultaneously sampled with the PIV measurements and taken on the surrounding boundary layer plate and at several locations on the turret geometry. Active flow control of the turret wake was performed around the leading edge of the turret aperture using dynamic suction in steady open-loop, unsteady open-loop, and simple closed-loop configurations. Analysis of the uncontrolled wake provided insight into the complex three-dimensional wake when evaluated spatially using PIV measurements and temporally using spectral analysis of the pressure measurements. Steady open-loop suction was found to significantly alter the spatial and temporal nature of the turret wake despite the control being applied locally to the aperture region of the turret. Unsteady open-loop and simple closed-loop control were found to provide similar levels of control to the steady open-loop forcing with a 45% reduction in the control input as calculated using the jet momentum coefficient. The data set collected provides unique information regarding the development of the baseline three-dimensional wake and the wake with three different active flow control configurations. These data can be used to

  14. Computational investigation of the flow field contribution to improve electricity generation in granular activated carbon-assisted microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Zhao, Lei; Li, Jian; Battaglia, Francine; He, Zhen

    2016-11-01

    Microbial fuel cells (MFCs) offer an alternative approach to treat wastewater with less energy input and direct electricity generation. To optimize MFC anodic performance, adding granular activated carbon (GAC) has been proved to be an effective way, most likely due to the enlarged electrode surface for biomass attachment and improved mixing of the flow field. The impact of a flow field on the current enhancement within a porous anode medium (e.g., GAC) has not been well understood before, and thus is investigated in this study by using mathematical modeling of the multi-order Butler-Volmer equation with computational fluid dynamics (CFD) techniques. By comparing three different CFD cases (without GAC, with GAC as a nonreactive porous medium, and with GAC as a reactive porous medium), it is demonstrated that adding GAC contributes to a uniform flow field and a total current enhancement of 17%, a factor that cannot be neglected in MFC design. However, in an actual MFC operation, this percentage could be even higher because of the microbial competition and energy loss issues within a porous medium. The results of the present study are expected to help with formulating strategies to optimize MFC with a better flow pattern design.

  15. The investigation of the impacts of major disasters, on the basis of the Van earthquake (October 23, 2011, Turkey), on the profile of the injuries due to occupational accidents.

    PubMed

    Hekimoglu, Yavuz; Dursun, Recep; Karadas, Sevdegul; Asirdizer, Mahmut

    2015-10-01

    The purpose of this study is to identify the impacts of major disasters, on the basis of the Van earthquake (October 23, 2011, Turkey), on the profile of the injuries due to occupational accidents. In this study, we evaluated 245 patients of occupational accidents who were admitted to emergency services of Van city hospitals in the 1-year periods including pre-earthquake and post-earthquake. We determined that there was a 63.4% (P < 0.05) increase in work-related accidents in the post-earthquake period compared to the pre-earthquake period. Also, injuries due to occupational accidents increased 211% (P < 0.05) in the construction industry, the rate of injuries due to falls from height increased 168% (P < 0.05), and the rate of traumas to the head and upper limbs increased 200% (P < 0.05) and 130% (P < 0.05), respectively, in the post-earthquake period compared to the pre-earthquake period. We determined that the ignoring of measures for occupational health and safety by employers and employees during conducted rapid construction activities and post-earthquake restoration works in order to remove the effects of the earthquake increased the number of work accidents. In this study, the impact of disasters such as earthquakes on the accidents at work was evaluated as we have not seen in literature. This study emphasizes that governments should make regulations and process relating to the post-disaster business before the emergence of disaster by taking into account factors that may increase their work-related accidents.

  16. Active seismic monitoring of changes of the reflection response of a crystalline shear zone due to fluid injection in the crust at the Continental Deep Drilling Site, Germany

    NASA Astrophysics Data System (ADS)

    Beilecke, T.; Kurt, B.; Stefan, B.

    2005-12-01

    In theory and in the laboratory variations of the hydraulic pressure can be detected with seismic methods: A lowering of the hydraulic pressure leads to the closure of micro-cracks within the rock (increase of the differential or effective pressure). Subsequently, the seismic velocities increase. An increase of the hydraulic pressure leads to reverse seismic effects. Consequently, seismic impedance contrasts and associated reflection amplitudes vary in the case of a propagating fluid pressure front in a rock matrix with inhomogeneous permeability - as is the case at shear zones. The largest amplitude changes can be expected with vertical ray inclination on the impedance contrast. Generally, the expected effects are small however (Kaselow, 2004). The practical utilization of active seismics for the detection of pressure changes at large scale in hard rock is currently being studied at the Continental Deep Drilling Site (KTB). The injection of water (200 l/min) in a depth of about 4000 m into the so-called SE2 shear zone in the KTB pilot hole was monitored with active seismics between May 2004 and April 2005. The core of the experiment layout is a fixed 5-arm geophone array consisting of 24 3-component geophones, buried at about 70 cm depth. The source signal is a vertical vibrator sweep of 30 s length with the spectrum 30-120 Hz. The signal is sent into the ground 32 times during each cycle, detected with the array and recorded separately for each geophone channel, without prior correlation with the source signal. This allows maximum post-processing with seismic processing and analysis tools and especially permits the use of array properties to increase the signal-to-noise ratio. Critical parameters of the experiment are the repeatability of the source signal as well as the stability of the receiver properties. Another pivot is the hydraulic pressure and its distribution built up within the rock matrix. Estimations based on model calculations show that a change of

  17. Decrease in water activity due to fluid absent partial melting monitored with water content in biotite in the Western Adamello contact aureole (Italy)

    NASA Astrophysics Data System (ADS)

    Siron, Guillaume; Baumgartner, Lukas; Bouvier, Anne-Sophie; Vennemann, Torsten

    2016-04-01

    interpret the concentration of OH- to be influenced by water activity within the rocks, and temperature. Our results confirm that oxy-biotite is a non-negligible component, but in the case of prograde metamorphism we do not interpret this as the consequence of a Ti-oxygen exchange only, but also as the consequence of a decrease in water activity due to partial melting. Bauer, K. K., & Vennemann, T. W. (2014). Analytical methods for the measurement of hydrogen isotope composition and water content in clay minerals by TC/EA. Chemical Geology, 363(C), 229-240. Cesare, B., Satish-Kumar, M., Cruciani, G., Pocker, S., & Nodari, L. (2008). Mineral chemistry of Ti-rich biotite from pegmatite and metapelitic granulites of the Kerala Khondalite Belt (southeast India): Petrology and further insight into titanium substitutions. American Mineralogist, 93(2-3), 327-338. Floess, D., & Baumgartner, L. (2013). Formation of garnet clusters during polyphase metamorphism. Terra Nova, 25(2), 144-150. Munoz, J. L. (1984). F-OH and Cl-OH Exchange in Micas with Applications to Hydrothermal Ore Deposits. Reviews in Mineralogy and Geochemistry, 13, 469-493.

  18. Smog Chamber Investigation on the Iron-Catalyzed Activation of Chloride from Modeled Saltpans

    NASA Astrophysics Data System (ADS)

    Wittmer, Julian; Bleicher, Sergej; Oeste <, Franz Dietrich; Zetzsch, Cornelius

    2014-05-01

    Halogen activation on sea spray aerosols and other halide surfaces and thus the formation of reactive halogen species (RHS), influencing trace and greenhouse gases, has become an important topic of research in recent years. In this context the chloride and bromide activation, in particular the formation of RHS by photochemically induced halogen release from (sea) salt surface and reactions with ozone (O3) and nitrogen oxides (NOx), came into focus [1,2]. Our studies concentrate on the quantification of atomic chlorine (Cl), bromine (Br) and hydroxyl (OH) radicals in the gas phase above lab-models of salt pans, enriched in iron(III) chloride (FeCl3), that are exposed to simulated sunlight in a smog chamber. The applied radical clock method [3] results in time profiles and source strengths for Cl, Br and OH, which are combined with the various compositions of humidified salts. In particular, the influence of bromine, sulfate, oxalate, and catechol on the FeCl3 enriched salt is investigated. Comparable investigations only exist for the aqueous phase chemistry of FeCl3 (e.g. [4]). Driven by the photolytic reduction from Fe(III) to Fe(II), an enormous amount of chlorine atoms (>107 cm-3) could be detected for sodium chloride (NaCl) salt pans with low addition of FeCl3 (0.5 - 2 wt%), even in an O3 and NOx free environment. The Cl2 source strength reaches a maximum of 8×1011 Cl2 molecules per cm3 within the first hour of the experiment, corresponding to a Cl2 mixing ratio of 30 ppbv at standard pressure. These concentrations exceeded the release above pure NaCl samples by a factor of 1000. A crucial factor for the Cl2 release is the pH and thus the formation of iron(III) complexes on the salt crystals that differ in their sensitivity for photolysis. Whereas the presence of sodium bromide normally strengthens the chlorine release, a suppression accompanied by strong bromine activation (>1010 cm-3) could be observed for iron enriched samples. Furthermore, the addition of

  19. Protective effects of statins on L-DOPA neurotoxicity due to the activation of phosphatidylinositol 3-kinase and free radical scavenging in PC12 cell culture.

    PubMed

    Koh, Seong-Ho; Park, Hyun-Hee; Choi, Na-Young; Lee, Kyu-Yong; Kim, Sangjae; Lee, Young Joo; Kim, Hee-Tae

    2011-01-25

    Neurotoxic effects have been suggested for l-3,4-dihydroxyphenylalanine (L-DOPA), while neuroprotective effects have been proposed for statins. We investigated whether certain statins (simvastatin or pitavastatin) could inhibit L-DOPA neurotoxicity. Neuronally-differentiated PC12 (nPC12) cells were treated with L-DOPA and/or statins for 24h, and their viabilities were measured using a cell counting kit, trypan blue staining, and 4',6-diamidino-2-phenylindole (DAPI) staining. Free radical and specific intracellular signaling protein levels were measured with 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) and Western blotting, respectively. High concentrations of l-DOPA reduced nPC12 cell viability, but combined treatment with statins restored viability. Treatment with 200 μM L-DOPA increased free radical and hydroxyl radical levels, but combined treatment with 5 μM statins decreased these levels. Survival-related signaling proteins were decreased in nPC12 cells treated with 200 μM L-DOPA, but combined treatment with 5μM statins significantly increased the levels of these proteins. Treatment with 200 μM L-DOPA significantly increased death-related signaling proteins, while combined treatment with 5 μM statins reduced the levels of these proteins. Pretreatment with LY294002, a phosphatidylinositol 3 kinase (PI3K) inhibitor, before combined treatment with statins and L-DOPA almost completely blocked the protective effects of statins. These results indicate that statins reduce L-DOPA neurotoxicity by lowering oxidative stress and by enhancing survival signals and inhibiting death signals via activation of the PI3K pathway.

  20. Alternative disposal for Investigation Derived Wastes (IDW) containing low activity source material

    SciTech Connect

    Downey, H.T.; Majer, T.

    2007-07-01

    As part of a Remedial Investigation (RI) at a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Site, approximately 77,111 kg (85 tons) I would use the actual tons of investigation derived wastes (IDW) were generated from exploratory soil borings and as part of removal activities at a former drum burial area. Characterization of these materials indicated elevated concentrations of metals including uranium and thorium (source material). Concentrations of uranium and thorium were at levels less than 0.05% by mass, which is the threshold for exempt source material under Nuclear Regulatory Commission (NRC) regulations. Disposal of this material was evaluated as low-level radioactive waste and as exempt radioactive waste. The NRC has established a process for evaluation and review of exempt source material transfer and direct disposal in a Resource Conservation and Recovery Act (RCRA) landfill. These requests are normally approved if the dose to a member of the general public is unlikely to exceed 0.25 mSv per year (25 milli-rem per year). The soil was evaluated for disposal as exempt radioactive waste at a RCRA landfill, which included dose modeling to workers during transportation and disposal as well as potential dose to members of the public after closure of the disposal facility. These evaluations determined that the potential dose was very small, and review by the agreement state regulatory agency indicated that this disposal process should not result in any undue hazard to public health and safety or property. The advantage of this approach is that disposal of 77,111 kg (85 tons) of IDW at a RCRA landfill is estimated to result in a savings of $80,000 as compared to disposal as low-level radioactive waste. Alternative waste disposal of exempt source material provides more disposal options and can lead to significant cost savings. (authors)

  1. Mercury's Magnetic Field: Active, Thermoelectric, or Decaying Dynamo or Crustal Remanence? - The MESSENGER Magnetic Field Investigation

    NASA Astrophysics Data System (ADS)

    Lohr, D. A.; Acuna, M. H.; Anderson, B. J.; Korth, H.; Slavin, J. A.; Solomon, S. C.; McNutt, R. L.

    2005-12-01

    The discovery of Mercury's intrinsic magnetic field in 1974 by Mariner 10 was a surprise because the planet's size, thermal state, and angular momentum seemed to rule out the possibility of an active dynamo. Additional encounters of Mercury by the Mariner 10 spacecraft in 1975 confirmed the initial results and allowed the estimation of the planetary magnetic dipole moment to within perhaps a factor of two. This discovery prompted a variety of suggestions for the source of the intrinsic field. The presence of sufficient sulfur in the outer core would allow a thin fluid outer core to persist to the present and perhaps serve as host to a thin-shell dynamo. Recent dynamo simulations under conditions appropriate to Mercury support this possibility and point to aspects of the external field that may be observable from an orbiting spacecraft. Remanent magnetization of the crust and mantle by a now-dead core dynamo field was proposed as an alternative explanation of the Mariner 10 observations in 1976, but this suggestion has been questioned on the grounds that the characteristic time between polarity reversals of a core dynamo field is likely much less than the timescale for acquisition of thermoremanence by the cooling crust and upper mantle. The discovery by Mars Global Surveyor (MGS) in 1997 of an intensely magnetized Martian crust added fuel to this debate, because the Mariner 10 measurements can be reproduced if Mercury's crust is approximated by a magnetized shell having an intrinsic magnetization of the same order of magnitude as that suggested for Mars by the MGS measurements. The MESSENGER magnetic field investigation is designed to address this and other fundamental questions regarding the nature and origin of Mercury's internal field as well as the planet's thermal history. We present here a summary of the MESSENGER magnetic field investigation goals and an assessment of observations acquired during the spacecraft's Earth flyby on 2 August 2005.

  2. Investigation and analysis of single nucleotide polymorphisms in Janus kinase/signal transducer and activator of transcription genes with leukemia.

    PubMed

    Zhong, Yuejiao; Wu, Jianzhong; Chen, Baoan; Ma, Rong; Cao, Haixia; Wang, Zhuo; Cheng, Lu; Ding, Jiahua; Feng, Jifeng

    2012-06-01

    Aberrant activation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway may predispose to leukemia due to deregulation of proliferation, differentiation or apoptosis. This study was conducted to investigate whether any association exists between genetic polymorphisms in the JAK2, STAT3 and STAT5 genes and individual susceptibility to leukemia. A case-control study was carried out using a Chinese sample set with 344 cases of leukemia and 346 controls matched by age and ethnicity. Genomic DNA was assayed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) on 13 single nucleotide polymorphisms (SNPs). Genotype analyses showed that two SNPs, namely rs17886724 and rs2293157 located in STAT3 and STAT5, respectively, were significantly associated with leukemia (p < 0.05 for all). Interaction analyses of SNPs (rs17886724|rs2293157; rs11079041| rs2293157) showed that there were inferior associations in chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML) compared to the control group (0.1 > p > 0.05). Linkage disequilibrium existed between rs11079041 and rs2293157 in both leukemia and control groups (r(2) = 0.7). The haplotypes displayed significant association between rs11079041 and rs2293157 in both leukemia and control groups (p < 0.05). The accuracy rate of the support vector machine (SVM) classification model in making a prediction of leukemia was 97%. The results indicated that STAT3 and STAT5 gene SNPs may be prognostic of leukemia.

  3. Hi-C Observations of an Active Region Corona, and Investigation of the Underlying Magnetic Structure

    NASA Technical Reports Server (NTRS)

    Tiwari, S. K.; Alexander, C. E.; Winebarger, A.; Moore, R. L.

    2014-01-01

    The solar corona is much hotter (>=10(exp 6) K) than its surface (approx 6000 K), puzzling astrophysicists for several decades. Active region (AR) corona is again hotter than the quiet Sun (QS) corona by a factor of 4-10. The most widely accepted mechanism that could heat the active region corona is the energy release by current dissipation via reconnection of braided magnetic field structure, first proposed by E. N. Parker three decades ago. The first observational evidence for this mechanism has only recently been presented by Cirtain et al. by using High-resolution Coronal Imager (Hi-C) observations of an AR corona at a spatial resolution of 0.2 arcsec, which is required to resolve the coronal loops, and was not available before the rocket flight of Hi-C in July 2012. The Hi-C project is led by NASA/MSFC. In the case of the QS, work done by convection/granulation on the inter-granular feet of the coronal field lines translates into the heat observed in the corona. In the case of the AR, as here, there could be flux emergence, cancellation/submergence, or shear flows generating large stress and tension in coronal field loops which is released as heat in the corona. We are currently investigating the changes taking place in photospheric feet of the magnetic field involved with brightenings in the Hi-C AR corona. For this purpose, we are also using SDO/AIA data of +/- 2 hours around the 5 minutes Hi-C flight. In the present talk, I will first summarize some of the results of the Hi-C observations and then present some results from our recent analysis on what photospheric processes feed the magnetic energy that dissipates into heat in coronal loops.

  4. Investigating the applicability of activity-based quantum mechanics in a few high school physics classrooms

    NASA Astrophysics Data System (ADS)

    Escalada, Lawrence Todd

    Quantum physics is not traditionally introduced in high school physics courses because of the level of abstraction and mathematical formalism associated with the subject. As part of the Visual Quantum Mechanics project, activity-based instructional units have been developed that introduce quantum principles to students who have limited backgrounds in physics and mathematics. This study investigates the applicability of one unit, Solids & Light, that introduces quantum principles within the context of learning about light emitting diodes. An observation protocol, attitude surveys, and questionnaires were used to examine the implementation of materials and student-teacher interactions in various secondary physics classrooms. Aspects of Solids & Light including the use of hands-on activities, interactive computer programs, inexpensive materials, and the focus on conceptual understanding were very applicable in the various physics classrooms observed. Both teachers and students gave these instructional strategies favorable ratings in motivating students to make observations and to learn. These ratings were not significantly affected by gender or students, attitudes towards physics or computers. Solid's & Light was applicable in terms of content and teaching style for some teachers. However, a mismatch of teaching styles between some instructors and the unit posed some problems in determining applicability. Observations indicated that some instructors were not able to utilize the exploratory instructional strategy of Solid's & Light. Thus, Solids & Light must include additional support necessary to make the instructor comfortable with the subject matter and pedagogical style. With these revisions, Solids & Light, will have all the key components to make its implementation in a high school physics classroom a successful one.

  5. Investigation of nano lipid vesicles of methotrexate for anti-rheumatoid activity

    PubMed Central

    Prabhu, Prabhakara; Shetty, Rakshith; Koland, Marina; Vijayanarayana, K; Vijayalakshmi, KK; Nairy, M Harish; Nisha, GS

    2012-01-01

    Background The purpose of this study was to formulate and evaluate nano lipid vesicles of methotrexate (MTX) for its anti-rheumatoid activity. Methods In this study the principle of both active as well as passive targeting using MTX-loaded stealth liposomes as per the magic gun approach was followed. Stealth liposomes of MTX were prepared by thin-film hydration method using a PEGylated phospholipid-like DSPE-MPEG 2000. Similarly, conventional liposomes were prepared using phospholipids like DPPC and DSPC. Conventional liposomes were coated with a hydrophilic biocompatible polymer like chitosan. They were investigated for their physical properties and in vitro release profile. Further, in vivo screening of the formulations for their anti-rheumatoid efficacy was carried out in rats. Rheumatoid arthritis was induced in male Wistar-Lewis rats using complete Freund’s adjuvant (1 mg/mL Mycobacterium tuberculosis, heat killed in mineral oil). Results It was found that chitosan coating of the conventional liposomes increased the physical stability of the liposomal suspension as well as its entrapment efficiency. The size of the unsonicated lipid vesicles was found to be in the range of 8–10 μm, and the sonicated lipid vesicles in the range of 210–260 nm, with good polydispersity index. Further, chitosan-coated conventional liposomes and the PEGylated liposomes released the drug for a prolonged period of time, compared to the uncoated conventional liposomes. It was found that there was a significant reduction in edema volume in the rat group administered with the test stealth liposomal formulations and chitosan-coated conventional liposomes (PEGylated and chitosan-coated conventional) compared to that of the control and standard (administered with free MTX) group of rats. PEGylated liposomes showed almost equal efficacy as that of the chitosan-coated conventional liposomes. Conclusion Lipid nano vesicles of MTX can be administered by intravenous route, whereby the

  6. Investigation of the estrogenic activities of pesticides from Pal-dang reservoir by in vitro assay.

    PubMed

    Oh, Young Jin; Jung, Yeon Jung; Kang, Joon-Wun; Yoo, Young Sook

    2007-12-15

    Endocrine disruptors, when absorbed into the body, interfere with the normal function by mimicking or blocking the hormone system. To investigate compounds mimicking estrogen in the drinking water source of the residence of Seoul, the Pal-dang reservoir was monitored over a period of 5 years, between 2000 and 2004. Nine kinds of pesticide (carbaryl, DBCP, diazinon, fenitrothion, fenobucarb, flutolanil, iprobenphos, isoprothiolane and parathion) were found to exist in the river water sample. These compounds were detected at low concentrations in the water samples. The total concentration and those of each of these pesticides were below the permissible limits of the National Institute of Environmental Research (NIER), Korea. The estrogenic potencies of the nine pesticides were examined using an E-screen assay with MCF-7 BUS estrogen receptor (ER)-positive human breast cancer cells, with ER-negative MDA MB 231 cell lines also used to compare the results. From this, flutolanil and isoprothiolane were confirmed to have estrogenic activities as shown by the increasing MCF-7 BUS cell growth on their addition. In addition, the estrogen receptor alpha (ERalpha) protein, estrogen receptor-regulated progesterone receptor (PR) and pS2 mRNA levels on the addition of flutolanil and isoprothiolane were measured with MCF-7 BUS cells. It was observed that the levels of ERalpha protein decreased and those of the PR and pS2 genes increased on the addition of either flutolanil or isoprothiolane at concentrations of 10(-4) M, in the same manner as with the addition of 17beta-estradiol, which was used as the positive control. From these results, it was confirmed that flutolanil and isoprothiolane exhibit estrogenic activities, suggesting they might act through estrogen receptors.

  7. Experimental and theoretical investigations on the antioxidant activity of isoorientin from Crotalaria globosa

    NASA Astrophysics Data System (ADS)

    Deepha, V.; Praveena, R.; Sivakumar, Raman; Sadasivam, K.

    2014-03-01

    The increasing interests in naturally occurring flavonoids are well known for their bioactivity as antioxidants. The present investigations with combined experimental and theoretical methods are employed to determine the radical scavenging activity and phytochemicals present in Crotalaria globosa, a novel plant source. Preliminary quantification of ethanolic extract of leaves shows high phenolic and flavonoid content than root extract; also it is validated through DPPHrad assay. Further analysis is carried out with successive extracts of leaves of varying polarity of solvents. In DPPHrad and FRAP assays, ethyl acetate fraction (EtOAc) exhibit higher scavenging activity followed by ethanol fraction (EtOH) whereas in NOS assay ethanol fraction is slightly predominant over the EtOAc fraction. The LC-MS analysis provides tentative information about the presence of flavonoid C-glycoside in EtOAc fraction (yellow solid). Presence of flavonoid isorientin has been confirmed through isolation (PTLC) and detected by spectroscopy methods (UV-visible and 1H NMR). Utilizing B3LYP/6-311G (d,p) level of theory the structure and reactivity of flavonoid isoorientin theoretically have been explored. The analysis of the theoretical Bond dissociation energy values, for all Osbnd H sites of isoorientin reveals that minimum energy is required to dissociate H-atom from B-ring than A and C-rings. In order to validate the antioxidant characteristics of isoorientin the relevant molecular descriptors IP, HOMO-LUMO, Mulliken spin density analysis and molecular electrostatic potential surfaces have been computed and interpreted. From experimental and theoretical results, it is proved that isoorientin can act as potent antiradical scavenger in oxidative system.

  8. Investigating the AGN activity and black hole masses in low surface brightness galaxies

    NASA Astrophysics Data System (ADS)

    Subramanian, Smitha; Sethuram, Ramya; Das, Mousumi; George, Koshy; Thirupathi, Sivarani; Prabhu, Tushar P.

    2016-02-01

    We present an analysis of the optical nuclear spectra from the active galactic nuclei (AGN) in a sample of giant low surface brightness (GLSB) galaxies. GLSB galaxies are extreme late type spirals that are large, isolated and poorly evolved compared to regular spiral galaxies. Earlier studies have indicated that their nuclei have relatively low mass black holes. Using data from the Sloan Digital Sky Survey (SDSS), we selected a sample of 30 GLSB galaxies that showed broad Hα emission lines in their AGN spectra. In some galaxies such as UGC 6284, the broad component of Hα is more related to outflows rather than the black hole. One galaxy (UGC 6614) showed two broad components in Hα, one associated with the black hole and the other associated with an outflow event. We derived the nuclear black hole (BH) masses of 29 galaxies from their broad Hα parameters. We find that the nuclear BH masses lie in the range 105 - 107 M⊙. The bulge stellar velocity dispersion σ e was determined from the underlying stellar spectra. We compared our results with the existing BH mass - velocity dispersion (M BH-σ e ) correlations and found that the majority of our sample lie in the low BH mass regime and below the M BH-σ e correlation. The effects of galaxy orientation in the measurement of σ e and the increase of σ e due to the effects of bar are probable reasons for the observed offset for some galaxies, but in many galaxies the offset is real. A possible explanation for the M BH-σ e offset could be lack of mergers and accretion events in the history of these galaxies which leads to a lack of BH-bulge co-evolution.

  9. Detailed investigation of the microbial community in foaming activated sludge reveals novel foam formers

    NASA Astrophysics Data System (ADS)

    Guo, Feng; Wang, Zhi-Ping; Yu, Ke; Zhang, T.

    2015-01-01

    Foaming of activated sludge (AS) causes adverse impacts on wastewater treatment operation and hygiene. In this study, we investigated the microbial communities of foam, foaming AS and non-foaming AS in a sewage treatment plant via deep-sequencing of the taxonomic marker genes 16S rRNA and mycobacterial rpoB and a metagenomic approach. In addition to Actinobacteria, many genera (e.g., Clostridium XI, Arcobacter, Flavobacterium) were more abundant in the foam than in the AS. On the other hand, deep-sequencing of rpoB did not detect any obligate pathogenic mycobacteria in the foam. We found that unknown factors other than the abundance of Gordonia sp. could determine the foaming process, because abundance of the same species was stable before and after a foaming event over six months. More interestingly, although the dominant Gordonia foam former was the closest with G. amarae, it was identified as an undescribed Gordonia species by referring to the 16S rRNA gene, gyrB and, most convincingly, the reconstructed draft genome from metagenomic reads. Our results, based on metagenomics and deep sequencing, reveal that foams are derived from diverse taxa, which expands previous understanding and provides new insight into the underlying complications of the foaming phenomenon in AS.

  10. An active interface between medical science and aeronautical technology: the physiological investigations for the XC-35.

    PubMed

    Chapin, S L

    1991-01-01

    Although the advantages of flight at high altitude were early recognized, so also were the physiological problems standing in the way of its realization. The idea of surmounting such problems by means of a pressurized cabin was advocated as early as 1909, while the first attempt to translate the concept into actuality occurred in 1921. Neither it nor several successive attempts enjoyed any real success until a project launched by the U. S. Air Corps in 1935 produced a breakthrough aircraft designated the XC-35. The major reason for the favorable termination of that venture was the thoroughness of the engineering involved. But it is equally notable that this was the first instance in the age of powered flight where there was an active collaboration between the scientists and engineers, a rather curious circumstance in view of the fact that the achievement of altitude record-setting balloon flights in the nineteenth century had owed a great deal to an interconnection of aeronauts and scientists' laboratories. This paper focuses on the physiological investigations which informed the XC-35 engineers while at the same time bringing into being a new aeromedical laboratory taking the first small step toward turning aeromedicine into space medicine.

  11. Investigating microbial activities of electrode-associated microorganisms in real-time

    PubMed Central

    Aracic, Sanja; Semenec, Lucie; Franks, Ashley E.

    2014-01-01

    Electrode-associated microbial biofilms are essential to the function of bioelectrochemical systems (BESs). These systems exist in a number of different configurations but all rely on electroactive microorganisms utilizing an electrode as either an electron acceptor or an electron donor to catalyze biological processes. Investigations of the structure and function of electrode-associated biofilms are critical to further the understanding of how microbial communities are able to reduce and oxidize electrodes. The community structure of electrode-reducing biofilms is diverse and often dominated by Geobacter spp. whereas electrode-oxidizing biofilms are often dominated by other microorganisms. The application of a wide range of tools, such as high-throughput sequencing and metagenomic data analyses, provide insight into the structure and possible function of microbial communities on electrode surfaces. However, the development and application of techniques that monitor gene expression profiles in real-time are required for a more definite spatial and temporal understanding of the diversity and biological activities of these dynamic communities. This mini review summarizes the key gene expression techniques used in BESs research, which have led to a better understanding of population dynamics, cell–cell communication and molecule-surface interactions in mixed and pure BES communities. PMID:25506343

  12. Investigation of the density wave activity in the thermosphere above 220 KM

    NASA Astrophysics Data System (ADS)

    Illés-Almár, E.; Almár, I.; Bencze, P.

    Based on CACTUS (Capteur Accélérométrique Capacitif Triaxial Ultra Sensible) microaccelerometer measurements it has been demonstrated that - after taking into account all effects included in the MSIS'86=CIRA'86 (COSPAR, 1988) model - there are residual fluctuations in the density of the upper atmosphere much larger than that the accuracy of the measurements can account for. These fluctuations are attributed to some kind of wave activity (Illés-Almár, 1993, Illés-Almár et al. 1996a). The average deviations from a model are considered as a measure of the amplitude of the waves in the atmosphere and are analysed as a function of geomagnetic coordinates, altitude and local solar time, in order to identify possible wave sources either in the lower lying atmosphere or in the thermosphere/ionosphere system. As a first step, the present investigation intends to make a map of the wave pattern by this method.

  13. New investigational drugs with single-agent activity in multiple myeloma

    PubMed Central

    Rajan, A M; Kumar, S

    2016-01-01

    The treatment of multiple myeloma (MM) is rapidly evolving. In the United States, four drugs (panobinostat, ixazomib, daratumumab and elotuzumab) were approved for the treatment of MM in 2015. As a result of improved diagnosis and therapy, there has been a dramatic improvement in the outcome of MM in the last decade, probably more than any other malignancy. Numerous agents continue to be studied in preclinical models and in clinical trials, with many demonstrating clinical efficacy that appears promising enough to have a trajectory for regulatory approval. The purpose of this article is to summarize the current data and provide perspective on new investigational agents with promising single-agent activity in MM. The agents reviewed include Isatuximab, an anti-CD38 monoclonal antibody; marizomib, a new proteasome inhibitor; oprozomib, an oral proteasome inhibitor; filanesib (ARRY-520), a kinesin spindle protein inhibitor; dinaciclib, a cyclin-dependent kinase inhibitor; venetoclax (ABT-199), a selective BCL-2 inhibitor; and LGH-447, pan PIM kinase inhibitor. PMID:27471867

  14. Radiosensitization of human pancreatic cancer cells by MLN4924, an investigational NEDD8-activating enzyme inhibitor.

    PubMed

    Wei, Dongping; Li, Hua; Yu, Jie; Sebolt, Jonathan T; Zhao, Lili; Lawrence, Theodore S; Smith, Peter G; Morgan, Meredith A; Sun, Yi

    2012-01-01

    Radiotherapy is used in locally advanced pancreatic cancers in which it can improve survival in combination with gemcitabine. However, prognosis is still poor in this setting in which more effective therapies remain needed. MLN4924 is an investigational small molecule currently in phase I clinical trials. MLN4924 inhibits NAE (NEDD8 Activating Enzyme), a pivotal regulator of the E3 ubiquitin ligase SCF (SKP1, Cullins, and F-box protein), that has been implicated recently in DNA damage and repair. In this study, we provide evidence that MLN4924 can be used as an effective radiosensitizer in pancreatic cancer. Specifically, MLN4924 (20-100 nmol/L) effectively inhibited cullin neddylation and sensitized pancreatic cancer cells to ionizing radiation in vitro with a sensitivity enhancement ratio of approximately 1.5. Mechanistically, MLN4924 treatment stimulated an accumulation of several SCF substrates, including CDT1, WEE1, and NOXA, in parallel with an enhancement of radiation-induced DNA damage, aneuploidy, G(2)/M phase cell-cycle arrest, and apoptosis. RNAi-mediated knockdown of CDT1 and WEE1 partially abrogated MLN4924-induced aneuploidy, G(2)/M arrest, and radiosensitization, indicating a causal effect. Furthermore, MLN4924 was an effective radiosensitizer in a mouse xenograft model of human pancreatic cancer. Our findings offer proof-of-concept for use of MLN4924 as a novel class of radiosensitizer for the treatment of pancreatic cancer.

  15. Synthesis, characterization, investigation of biological activity and theoretical studies of hydrazone compounds containing choloroacetyl group

    NASA Astrophysics Data System (ADS)

    Cukurovali, Alaaddin; Yilmaz, Engin

    2014-10-01

    In this study, three new hydrazide-hydrazone derivative compounds which contain choloroacetyl group have been synthesized and characterized. In the characterization, spectral techniques such as IR, 1H NMR, 13C NMR and UV-Vis spectroscopy techniques were used. Antibacterial effects of the synthesized compounds were investigated against Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. In the theoretical calculations Gaussian 09 software was used with the DFT/6-311+(d,p) basis set. Experimental X-ray analysis of compounds has not been studied. Theoretical bond lengths of synthesized compounds were compared with experimental bond lengths of a similar compound. Theoretical and experimental bond lengths are in good agreement with R2: 0.896, 0.899 and 0.900 for compounds 1, 2, and 3, respectively. For antibacterial activity, the most effective one was found to be N‧-(4-bromobenzylidene)-2-chloro-N-(4-(3-methyl-3-phenylcyclobutyl)-thiazol-2-yl) acetohydrazide against P.aeroginaosa ATTC 27853, among the studied compounds.

  16. Theoretical and experimental investigations on the structures of purified clay and acid-activated clay

    NASA Astrophysics Data System (ADS)

    Yang, Tao; Wen, Xiao-Dong; Li, Junfen; Yang, Liming

    2006-07-01

    The purified and acidified montmorillonite clay were characterized by XRD, BET and TPD. These results show that acidified clay is provided with more surface area and acid sites. For NH 3-TPD, molecular NH 3 desorption on purified clay and acidified clay occurs at temperatures with 873 and 1000 K, respectively. It is shown for the existence for strong acid sites. By two reactions of the tetrahydropyranylation of n-propanol and the esterification of cyclo-2-pentene with acetic acid, it is shown that the acidified clay displays better catalytic activity for above two organic reactions. By density-functional theory (DFT) method, we have analyzed the structures of different substituted montmorillonite and the effect sorption behavior of Na + in different montmorillonite models. The result shows that the process of substitution will occur apart from octahedral aluminums. The adsorption of NH 3 on clay surfaces have been investigated using TPD and DFT. This is shown that acid sites locate at round the octahedral aluminums, and substitution of Al 3+ for tetrahedral Si will be favorable to NH 3 adsorption.

  17. Investigation of Hepatoprotective Activity of Induced Pluripotent Stem Cells in the Mouse Model of Liver Injury

    PubMed Central

    Chiang, Chih-Hung; Chang, Ching-Chih; Huang, Hui-Chun; Chen, Yi-Jen; Tsai, Ping-Hsing; Jeng, Shaw-Yeu; Hung, Shuen-Iu; Hsieh, Jung-Hung; Huang, Hsu-Shan; Chiou, Shih-Hwa; Lee, Fa-Yauh; Lee, Shou-Dong

    2011-01-01

    To date liver transplantation is the only effective treatment for end-stage liver diseases. Considering the potential of pluripotency and differentiation into tridermal lineages, induced pluripotent stem cells (iPSCs) may serve as an alternative of cell-based therapy. Herein, we investigated the effect of iPSC transplantation on thioacetamide- (TAA-) induced acute/fulminant hepatic failure (AHF) in mice. Firstly, we demonstrated that iPSCs had the capacity to differentiate into hepatocyte-like cells (iPSC-Heps) that expressed various hepatic markers, including albumin, α-fetoprotein, and hepatocyte nuclear factor-3β, and exhibited biological functions. Intravenous transplantation of iPSCs effectively reduced the hepatic necrotic area, improved liver functions and motor activity, and rescued TAA-treated mice from lethal AHF. 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate cell labeling revealed that iPSCs potentially mobilized to the damaged liver area. Taken together, iPSCs can effectively rescue experimental AHF and represent a potentially favorable cell source of cell-based therapy. PMID:21808596

  18. Experimental investigation on the thermal performance of heat storage walls coupled with active solar systems

    NASA Astrophysics Data System (ADS)

    Zhao, Chunyu; You, Shijun; Zhu, Chunying; Yu, Wei

    2016-12-01

    This paper presents an experimental investigation of the performance of a system combining a low-temperature water wall radiant heating system and phase change energy storage technology with an active solar system. This system uses a thermal storage wall that is designed with multilayer thermal storage plates. The heat storage material is expanded graphite that absorbs a mixture of capric acid and lauric acid. An experiment is performed to study the actual effect. The following are studied under winter conditions: (1) the temperature of the radiation wall surface, (2) the melting status of the thermal storage material in the internal plate, (3) the density of the heat flux, and (4) the temperature distribution of the indoor space. The results reveal that the room temperature is controlled between 16 and 20 °C, and the thermal storage wall meets the heating and temperature requirements. The following are also studied under summer conditions: (1) the internal relationship between the indoor temperature distribution and the heat transfer within the regenerative plates during the day and (2) the relationship between the outlet air temperature and inlet air temperature in the thermal storage wall in cooling mode at night. The results indicate that the indoor temperature is approximately 27 °C, which satisfies the summer air-conditioning requirements.

  19. Pharmacological Investigation of the Wound Healing Activity of Cestrum nocturnum (L.) Ointment in Wistar Albino Rats

    PubMed Central

    Nagar, Hemant Kumar; Srivastava, Amit Kumar; Srivastava, Rajnish; Kurmi, Madan Lal; Chandel, Harinarayan Singh; Ranawat, Mahendra Singh

    2016-01-01

    Objectives. The present study was aimed at investigating the wound healing effect of ethanolic extract of Cestrum nocturnum (L.) leaves (EECN) using excision and incision wound model. Methods. Wistar albino rats were divided into five groups each consisting of six animals; group I (left untreated) considered as control, group II (ointment base treated) considered as negative control, group III treated with 5% (w/w) povidone iodine ointment (Intadine USP), which served as standard, group IV treated with EECN 2% (w/w) ointment, and group V treated with EECN 5% (w/w) ointment were considered as test groups. All the treatments were given once daily. The wound healing effect was assessed by percentage wound contraction, epithelialization period, and histoarchitecture studies in excision wound model while breaking strength and hydroxyproline content in the incision wound model. Result. Different concentration of EECN (2% and 5% w/w) ointment promoted the wound healing activity significantly in both the models studied. The high rate of wound contraction (P < 0.001), decrease in the period for epithelialization (P < 0.01), high skin breaking strength (P < 0.001), and elevated hydroxyproline content were observed in animal treated with EECN ointments when compared to the control and negative control group of animals. Histopathological studies of the EECN ointments treated groups also revealed the effectiveness in improved wound healing. Conclusions. Ethanolic extract of Cestrum nocturnum (EECN) leaves possesses a concentration dependent wound healing effect. PMID:27018126

  20. Investigation of the use of various plant extracts activity in ruminant

    NASA Astrophysics Data System (ADS)

    Yüca, Songül; Gül, Mehmet; Ćaǧlayan, Alper

    2016-04-01

    The prohibition of the use of antibiotics and as a result of the adverse effect on health of synthetic products, research has focused on natural feed additives. In recent years, the diet of farm animals many feed additives have been used for various purposes or continues. These include as used in ruminant rations as plant extract thyme, anise, pepper, mint, garlic, rosemary, cinnamon, parsley, bay leaf, coconut, like used herbal extracts and their effects on the performance of ruminants was investigated. Antioxidant, antifungal, antiviral, anti-inflamaotry is known to have effects of plant extract. By stimulating the digestive system of ruminants, they increase the activity of digestive enzymes, to prevent environmental pollution caused by manure, regulations rumen fermentation, inhibition of methane formation and protein degradability in the rumen as well as the animal is known to have many benefits. The structure of essential oils and plant extracts in this collection, examining the use of ruminant livestock events and the importance of the use in animal nutrition into practice will be discussed.

  1. Detailed investigation of the microbial community in foaming activated sludge reveals novel foam formers

    PubMed Central

    Guo, Feng; Wang, Zhi-Ping; Yu, Ke; Zhang, T.

    2015-01-01

    Foaming of activated sludge (AS) causes adverse impacts on wastewater treatment operation and hygiene. In this study, we investigated the microbial communities of foam, foaming AS and non-foaming AS in a sewage treatment plant via deep-sequencing of the taxonomic marker genes 16S rRNA and mycobacterial rpoB and a metagenomic approach. In addition to Actinobacteria, many genera (e.g., Clostridium XI, Arcobacter, Flavobacterium) were more abundant in the foam than in the AS. On the other hand, deep-sequencing of rpoB did not detect any obligate pathogenic mycobacteria in the foam. We found that unknown factors other than the abundance of Gordonia sp. could determine the foaming process, because abundance of the same species was stable before and after a foaming event over six months. More interestingly, although the dominant Gordonia foam former was the closest with G. amarae, it was identified as an undescribed Gordonia species by referring to the 16S rRNA gene, gyrB and, most convincingly, the reconstructed draft genome from metagenomic reads. Our results, based on metagenomics and deep sequencing, reveal that foams are derived from diverse taxa, which expands previous understanding and provides new insight into the underlying complications of the foaming phenomenon in AS. PMID:25560234

  2. Pharmacological Investigation of the Wound Healing Activity of Cestrum nocturnum (L.) Ointment in Wistar Albino Rats.

    PubMed

    Nagar, Hemant Kumar; Srivastava, Amit Kumar; Srivastava, Rajnish; Kurmi, Madan Lal; Chandel, Harinarayan Singh; Ranawat, Mahendra Singh

    2016-01-01

    Objectives. The present study was aimed at investigating the wound healing effect of ethanolic extract of Cestrum nocturnum (L.) leaves (EECN) using excision and incision wound model. Methods. Wistar albino rats were divided into five groups each consisting of six animals; group I (left untreated) considered as control, group II (ointment base treated) considered as negative control, group III treated with 5% (w/w) povidone iodine ointment (Intadine USP), which served as standard, group IV treated with EECN 2% (w/w) ointment, and group V treated with EECN 5% (w/w) ointment were considered as test groups. All the treatments were given once daily. The wound healing effect was assessed by percentage wound contraction, epithelialization period, and histoarchitecture studies in excision wound model while breaking strength and hydroxyproline content in the incision wound model. Result. Different concentration of EECN (2% and 5% w/w) ointment promoted the wound healing activity significantly in both the models studied. The high rate of wound contraction (P < 0.001), decrease in the period for epithelialization (P < 0.01), high skin breaking strength (P < 0.001), and elevated hydroxyproline content were observed in animal treated with EECN ointments when compared to the control and negative control group of animals. Histopathological studies of the EECN ointments treated groups also revealed the effectiveness in improved wound healing. Conclusions. Ethanolic extract of Cestrum nocturnum (EECN) leaves possesses a concentration dependent wound healing effect.

  3. 2D-NMR investigation and in vitro evaluation of antioxidant, antigenotoxic and estrogenic/antiestrogenic activities of strawberry grape.

    PubMed

    D'Abrosca, Brigida; Lavorgna, Margherita; Scognamiglio, Monica; Russo, Chiara; Graziani, Vittoria; Piscitelli, Concetta; Fiorentino, Antonio; Isidori, Marina

    2017-03-27

    Strawberry grape is considered beneficial due to its extensive phytochemical properties. To expand the knowledge about the chemical constituents and the biological activities of the whole plant, 2D-NMR investigation has been carried out on pulp, peel, seeds, stalks and leaves. Catechin and epicatechin were identified as the main constituents of the seed extract, quercetin and ferulic acid were detected in the leaves and malvidin and cyanidin glucopyranoside in the peels. The leaf, stalk and seed extracts were found to be very rich in phytochemicals and were tested for their ability to reduce the mutagenicity and genotoxicity of standard agents via Salmonella mutagenicity assay and SOS chromotest, respectively. Moreover, the estrogen/antiestrogen-like activity was evaluated on the MCF-7 estrogen-responsive cells. Seed and stalk extracts had an elevated antimutagenic/antigenotoxic activity. Stalk extracts highly reduced the proliferative effect of natural estrogen, 17β-estradiol.

  4. Comparing Self-Reported Versus Objectively Measured Physical Activity Behavior: A Preliminary Investigation of Older Filipino American Women

    ERIC Educational Resources Information Center

    Atienza, Audie A.; King, Abby C.

    2005-01-01

    The importance of examining health behaviors, such as physical activity, among Filipino Americans is highlighted by their higher rates of chronic disease. As physical inactivity has been linked to chronic diseases (U.S. Department of Health and Human Services, 1996), this study investigated the physical activity levels of older Filipinas. This…

  5. Investigations on t