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Sample records for large potential difference

  1. Large electron screening effect in different environments

    NASA Astrophysics Data System (ADS)

    Cvetinovi?, Aleksandra; Lipoglavek, Matej; Markelj, Sabina; Vesi?, Jelena

    2015-10-01

    Electron screening effect was studied in the 1H(7Li,?)4He, 1H(11B,?)4He and 1H(19F,??)16O reactions in inverse kinematics on different hydrogen implanted targets. Results show large electron screening potentials strongly dependent on the proton number Z of the projectile.

  2. Electric potential differences across auroral generator interfaces

    NASA Astrophysics Data System (ADS)

    De Keyser, Johan; Echim, Marius

    2013-04-01

    Strong high-altitude auroral electric fields are often associated with magnetospheric interfaces. The high-altitude electric field profile depends on the properties of the plasmas on either side of the interface, as well as on the total electric potential difference across the structure. We have explored the role of this cross-field electric potential difference for the case of a tangential discontinuity interface. A Vlasov description is used to model how the equilibrium configuration depends on the transverse potential difference. We find that there exist limits to the potential difference, beyond which no equilibrium configuration of the interface can be sustained. It is further demonstrated how the plasma densities and temperatures affect the type of electric field profile in the transition, with monopolar electric fields appearing when the temperature contrast is large, supporting the observed association of monopolar fields with the plasma sheet boundary. The role of shear flow tangent to the interface is also examined.

  3. Electric potential differences across auroral generator interfaces

    NASA Astrophysics Data System (ADS)

    De Keyser, J.; Echim, M.

    2013-02-01

    Strong localized high-altitude auroral electric fields, such as those observed by Cluster, are often associated with magnetospheric interfaces. The type of high-altitude electric field profile (monopolar, bipolar, or more complicated) depends on the properties of the plasmas on either side of the interface, as well as on the total electric potential difference across the structure. The present paper explores the role of this cross-field electric potential difference in the situation where the interface is a tangential discontinuity. A self-consistent Vlasov description is used to determine the equilibrium configuration for different values of the transverse potential difference. A major observation is that there exist limits to the potential difference, beyond which no equilibrium configuration of the interface can be sustained. It is further demonstrated how the plasma densities and temperatures affect the type of electric field profile in the transition, with monopolar electric fields appearing primarily when the temperature contrast is large. These findings strongly support the observed association of monopolar fields with the plasma sheet boundary. The role of shear flow tangent to the interface is also examined.

  4. Large data analysis of different sensory modalities

    NASA Astrophysics Data System (ADS)

    Hsu, Ming-Kai; Szu, Harold

    2014-05-01

    We exam the historical remote digital video and in situ analog acoustic data analyses from the modern Large Data Analysis standpoint. We discussed a potential automation from traditional search engine to modern one. We exam the mathematic theory to answer where the nonlinear dimensional analysis assume a local flat space where linear eigenvalue provided the independent components, then the component is extrapolated to original nonlinear space and assume the local flat reduction remains meaningful at global nonlinear domain.

  5. Lichtheimia species exhibit differences in virulence potential.

    PubMed

    Schwartze, Volker U; Hoffmann, Kerstin; Nyilasi, Ildik; Papp, Tams; Vgvlgyi, Csaba; de Hoog, Sybren; Voigt, Kerstin; Jacobsen, Ilse D

    2012-01-01

    Although the number of mucormycosis cases has increased during the last decades, little is known about the pathogenic potential of most mucoralean fungi. Lichtheimia species represent the second and third most common cause of mucormycosis in Europe and worldwide, respectively. To date only three of the five species of the genus have been found to be involved in mucormycosis, namely L. corymbifera, L. ramosa and L. ornata. However, it is not clear whether the clinical situation reflects differences in virulence between the species of Lichtheimia or whether other factors are responsible. In this study the virulence of 46 strains of all five species of Lichtheimia was investigated in chicken embryos. Additionally, strains of the closest-related genus Dichotomocladium were tested. Full virulence was restricted to the clinically relevant species while all strains of L. hyalospora, L. sphaerocystis and Dichotomocladium species were attenuated. Although virulence differences were present in the clinically relevant species, no connection between origin (environmental vs clinical) or phylogenetic position within the species was observed. Physiological studies revealed no clear connection of stress resistance and carbon source utilization with the virulence of the strains. Slower growth at 37C might explain low virulence of L. hyalospora, L. spaherocystis and Dichotomocladium; however, similarly slow growing strains of L. ornata were fully virulent. Thus, additional factors or a complex interplay of factors determines the virulence of strains. Our data suggest that the clinical situation in fact reflects different virulence potentials in the Lichtheimiaceae. PMID:22911715

  6. Lichtheimia Species Exhibit Differences in Virulence Potential

    PubMed Central

    Schwartze, Volker U.; Hoffmann, Kerstin; Nyilasi, Ildik; Papp, Tams; Vgvlgyi, Csaba; de Hoog, Sybren; Voigt, Kerstin; Jacobsen, Ilse D.

    2012-01-01

    Although the number of mucormycosis cases has increased during the last decades, little is known about the pathogenic potential of most mucoralean fungi. Lichtheimia species represent the second and third most common cause of mucormycosis in Europe and worldwide, respectively. To date only three of the five species of the genus have been found to be involved in mucormycosis, namely L. corymbifera, L. ramosa and L. ornata. However, it is not clear whether the clinical situation reflects differences in virulence between the species of Lichtheimia or whether other factors are responsible. In this study the virulence of 46 strains of all five species of Lichtheimia was investigated in chicken embryos. Additionally, strains of the closest-related genus Dichotomocladium were tested. Full virulence was restricted to the clinically relevant species while all strains of L. hyalospora, L. sphaerocystis and Dichotomocladium species were attenuated. Although virulence differences were present in the clinically relevant species, no connection between origin (environmental vs clinical) or phylogenetic position within the species was observed. Physiological studies revealed no clear connection of stress resistance and carbon source utilization with the virulence of the strains. Slower growth at 37C might explain low virulence of L. hyalospora, L. spaherocystis and Dichotomocladium; however, similarly slow growing strains of L. ornata were fully virulent. Thus, additional factors or a complex interplay of factors determines the virulence of strains. Our data suggest that the clinical situation in fact reflects different virulence potentials in the Lichtheimiaceae. PMID:22911715

  7. Auditory sexual difference in the large odorous frog Odorrana graminea.

    PubMed

    Liu, Wei-Rong; Shen, Jun-Xian; Zhang, Yu-Jiao; Xu, Zhi-Min; Qi, Zhi; Xue, Mao-Qiang

    2014-04-01

    Acoustic communication is an important behavior in frog courtship. Male and female frogs of most species, except the concave-eared torrent frog Odorrana tormota, have largely similar audiograms. The large odorous frogs (Odorrana graminea) are sympatric with O. tormota, but have no ear canals. The difference in hearing between two sexes of the frog is unknown. We recorded auditory evoked near-field potentials and single-unit responses from the auditory midbrain (the torus semicircularis) to determine auditory frequency sensitivity and threshold. The results show that males have the upper frequency limit at 24kHz and females have the upper limit at 16kHz. The more sensitive frequency range is 3-15kHz for males and 1-8kHz for females. Males have the minimum threshold at 11kHz (58dB SPL), higher about 5dB than that at 3kHz for females. The best excitatory frequencies of single units are mostly between 3 and 5kHz in females and at 7-8kHz in males. The underlying mechanism of auditory sexual differences is discussed. PMID:24510208

  8. Large wind turbine generators. [NASA program status and potential costs

    NASA Technical Reports Server (NTRS)

    Thomas, R. L.; Donovon, R. M.

    1978-01-01

    The large wind turbine portion of the Federal Wind Energy Program consists of two major project efforts: (1) the Mod-0 test bed project for supporting research technology, and (2) the large experimental wind turbines for electric utility applications. The Mod-0 has met its primary objective of providing the entire wind energy program with early operations and performance data. The large experimental wind turbines to be tested in utility applications include three of the Mod-0A (200 kW) type, one Mod-1 (2000 kW), and possibly several of the Mod-2 (2500 kW) designs. This paper presents a description of these wind turbine systems, their programmatic status, and a summary of their potential costs.

  9. Exploiting the Potential Differences in Pasture Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperate grasses grown for pasture in Wisconsin exhibit a range of chemical and physical characteristics that influence their utilization by grazing cattle. Potential intake of all grasses declines with maturity due to decreasing cell wall digestiblity, but the leaves and stems of orchardgrass and...

  10. Energy potential and early operational experience for large wind turbines

    NASA Technical Reports Server (NTRS)

    Robbins, W. H.; Thomas, R. L.

    1980-01-01

    Projections for the total potential output of large wind turbines in the U.S. are reviewed. NASA has developed nine large windpowered generators, of 100 kW, 200 kW, 2 MW, and 2.5 MW capacities, with rotors 100-300 ft in diameter, and all with horizontal axes. Approximately 214,000 sq miles of the U.S. have been determined as having substantial wind regimes and terrain suitable for large wind turbine siting. This translates into 340,000 Mod 2 (2.5 MW) wind turbines producing 4.9 quads of electricity annually, equivalent to saving 2.5 billion barrels of oil/yr. The cost of electricity is seen as the critical factor in utility acceptance of large wind turbines, and the Mod 2 machines are noted to achieve the 2-4 cents/kWh (1977 dollars) COE which is necessary. Problems such as pollution, including visual, auditory, EM, and land use difficulties are considered, and solutions are indicated.

  11. Zooplankton as Potential Indicators of Biotic Condition in Large Rivers

    NASA Astrophysics Data System (ADS)

    Medley, K. A.; Havel, J. E.; Jack, J. D.

    2005-05-01

    As part of the Environmental Monitoring and Assessment Program (EMAP), supported by the U.S. Environmental Protection Agency, we are examining zooplankton diversity and abundance in three large rivers (Missouri, Ohio, and upper Mississippi). These rivers are particularly interesting because of large differences in their hydrologic patterns, resulting primarily from their different management strategies. Preliminary data from summer 2004 surveys of the Missouri and Ohio rivers reveals high taxonomic diversity of rotifers (32 genera), cladocerans (22 species), and copepods. Rotifers are numerically dominant in all river samples except in the late summer Ohio River samples, where they are occasionally co-dominant with calanoid copepods. Using multivariate analyses, we will present a comparison of zooplankton diversity between rivers, among sites within rivers, and correspondence with 35 physico-chemical properties of the river. These data will be used to develop bioindicators of the current condition of each river in order to support conservation and restoration decisions by management agencies.

  12. Assessment of large-scale flood events by different indicators

    NASA Astrophysics Data System (ADS)

    Thieken, A. H.; Merz, B.; Apel, H.

    2009-04-01

    An analysis of real large-scale flood events reveals that there is considerable variation in the return periods of the discharges within a river basin. The assessment of the return period of the whole event has thus to be evaluated on the basis of the overall impact of the event. For example, a frequency analysis of a series of annual flood damages (loss accumulation) would enable us to assign an exceedance probability to each event. However, in practise, time series of losses or other impact variables are hardly available or their usage is limited due to changes in time of the land use of the areas prone to inundation and their assets (building values, assets of companies and infrastructure). Using a reach at the River Rhine between the gauges Maxau and Rees as an example, a probabilistic model for the calculation of flood risks has been set up. The model is based on a flood classification at the river Rhine, which is then combined with flood frequency, correlation and regression analyses. Inundation areas are calculated by means of a hydraulic transformation. In the framework of a Monte-Carlo-Simulation 100 flood scenarios were derived and different impact parameters were determined, i.e. the total inundated area, the inundated settlement and industrial area, the exposed population as well as the potential damage to residential buildings as estimated by the loss model FLEMOps. The impact analyses were further used to construct a frequency distribution of each impact variable. By these the return periods of a number of historical flood events and a few static flood scenarios that were used for hazard mapping were estimated. The results will be discussed in the context of risk transfer systems and risk communication issues.

  13. Different mechanisms for dynamical arrest in largely asymmetric binary mixtures

    NASA Astrophysics Data System (ADS)

    Hendricks, J.; Capellmann, R.; Schofield, A. B.; Egelhaaf, S. U.; Laurati, M.

    2015-03-01

    Using confocal microscopy we investigate binary colloidal mixtures with large size asymmetry, in particular the formation of dynamically arrested states of the large spheres. The volume fraction of the system is kept constant, and as the concentration of small spheres is increased we observe a series of transitions of the large spheres to different arrested states: an attractive glass, a gel, and an asymmetric glass. These states are distinguished by the degree of dynamical arrest and the amount of structural and dynamical heterogeneity. The transitions between two different arrested states occur through melting and the formation of a fluid state. While a space-spanning network of bonded particles is found in both arrested and fluid states, only arrested states are characterized by the presence of a space-spanning network of dynamically arrested particles.

  14. Delayed difference scheme for large scale scientific simulations.

    PubMed

    Mudigere, Dheevatsa; Sherlekar, Sunil D; Ansumali, Santosh

    2014-11-21

    We argue that the current heterogeneous computing environment mimics a complex nonlinear system which needs to borrow the concept of time-scale separation and the delayed difference approach from statistical mechanics and nonlinear dynamics. We show that by replacing the usual difference equations approach by a delayed difference equations approach, the sequential fraction of many scientific computing algorithms can be substantially reduced. We also provide a comprehensive theoretical analysis to establish that the error and stability of our scheme is of the same order as existing schemes for a large, well-characterized class of problems. PMID:25479526

  15. Mixing device for materials with large density differences

    DOEpatents

    Gregg, D.W.

    1994-08-16

    An auger-tube pump mixing device is disclosed for mixing materials with large density differences while maintaining low stirring RPM and low power consumption. The mixing device minimizes the formation of vortexes and minimizes the incorporation of small bubbles in the liquid during mixing. By avoiding the creation of a vortex the device provides efficient stirring of full containers without spillage over the edge. Also, the device solves the problem of effective mixing in vessels where the liquid height is large compared to the diameter. Because of the gentle stirring or mixing by the device, it has application for biomedical uses where cell damage is to be avoided. 2 figs.

  16. Mixing device for materials with large density differences

    DOEpatents

    Gregg, David W. (Moraga, CA)

    1994-01-01

    An auger-tube pump mixing device for mixing materials with large density differences while maintaining low stirring RPM and low power consumption. The mixing device minimizes the formation of vortexes and minimizes the incorporation of small bubbles in the liquid during mixing. By avoiding the creation of a vortex the device provides efficient stirring of full containers without spillage over the edge. Also, the device solves the problem of effective mixing in vessels where the liquid height is large compared to the diameter. Because of the gentle stirring or mixing by the device, it has application for biomedical uses where cell damage is to be avoided.

  17. Peru onshore-deepwater basins should have large potential

    SciTech Connect

    Zuniga-Rivero, F.; Keeling, J.A.; Hay-Roe, H.

    1998-10-19

    Perupetro`s recent announcement that 13 offshore exploration blocks of nearly 1 million acres each will be offered for bids in the fourth quarter of 1998 has reawakened interest in this extensive, largely unexplored area. The new government policy, combined with the results of modern, deep-probing seismic surveys, has already led to a stepped-up search for oil and gas that will probably escalate. Most of Peru`s ten coastal basins are entirely offshore, but at both ends of the 1,500-mile coastline the sedimentary basins stretch from onshore across the continental shelf and down the continental slope. Two of these basin areas, both in the north, have commercial production. The third, straddling the country`s southern border, has never been drilled either on land or offshore. The Peruvian sectors of these three basins total roughly 50,000 sq miles in area, 75% offshore. All have major oil and gas potential. They are described individually in this article, an update in the ongoing studies last reported at the 1998 Offshore Technology Conference and in the first article of this series.

  18. A Methodology for Estimating Large-Customer Demand Response MarketPotential

    SciTech Connect

    Goldman, Charles; Hopper, Nicole; Bharvirkar, Ranjit; Neenan,Bernie; Cappers,Peter

    2007-08-01

    Demand response (DR) is increasingly recognized as an essential ingredient to well-functioning electricity markets. DR market potential studies can answer questions about the amount of DR available in a given area and from which market segments. Several recent DR market potential studies have been conducted, most adapting techniques used to estimate energy-efficiency (EE) potential. In this scoping study, we: reviewed and categorized seven recent DR market potential studies; recommended a methodology for estimating DR market potential for large, non-residential utility customers that uses price elasticities to account for behavior and prices; compiled participation rates and elasticity values from six DR options offered to large customers in recent years, and demonstrated our recommended methodology with large customer market potential scenarios at an illustrative Northeastern utility. We observe that EE and DR have several important differences that argue for an elasticity approach for large-customer DR options that rely on customer-initiated response to prices, rather than the engineering approaches typical of EE potential studies. Base-case estimates suggest that offering DR options to large, non-residential customers results in 1-3% reductions in their class peak demand in response to prices or incentive payments of $500/MWh. Participation rates (i.e., enrollment in voluntary DR programs or acceptance of default hourly pricing) have the greatest influence on DR impacts of all factors studied, yet are the least well understood. Elasticity refinements to reflect the impact of enabling technologies and response at high prices provide more accurate market potential estimates, particularly when arc elasticities (rather than substitution elasticities) are estimated.

  19. Horizontal differences in ecosystem metabolism of a large shallow lake

    NASA Astrophysics Data System (ADS)

    Idrizaj, Agron; Laas, Alo; Anijalg, Urmas; Nõges, Peeter

    2016-04-01

    The causes of horizontal differences in metabolic activities between lake zones are still poorly understood. We carried out a two-year study of lake metabolism in two contrasting parts of a large shallow lake using the open-water technique based on high-frequency measurements of dissolved oxygen concentrations. We expected that the more sheltered and macrophyte-rich southern part of the lake receiving a high hydraulic load from the main inflow will exhibit equal or higher rate of metabolic processes compared to the open pelagic zone, and higher temporal variability, including anomalous metabolic estimates such as negative gross primary production (GPP) or community respiration (CR) due to rapid water exchange. Our results showed that anomalous metabolic estimates occurred at both stations with a similar frequency and were related rather to certain wind directions, which likely contributed to stronger water exchange between the littoral and pelagic zones. Periods of auto- and heterotrophy (daily mean NEP> or <0) had a 50:50 distribution at the Central Station while the proportions were 30:70 at the Southern Station. High areal GPP estimated in our study exceeding nearly twice the long-term average 14C primary production, showed the advantages of the free-water technique in integrating the metabolism of all communities, a large part of which has remained undetected by the traditional bottle or chamber incubation techniques.

  20. Fermentation in the human large intestine: its physiologic consequences and the potential contribution of prebiotics.

    PubMed

    Macfarlane, George T; Macfarlane, Sandra

    2011-11-01

    The human large intestine harbors a complex microbiota containing many hundreds of different bacterial species. Although structure/function relationships between different components of the microbiota are unclear, this complex multicellular entity plays an important role in maintaining homeostasis in the body. Many of the physiologic properties of the microbiota can be attributed to fermentation and the production of short-chain fatty acids (SCFAs), particularly acetate, propionate, and butyrate. In healthy people, fermentation processes are largely controlled by the amounts and different types of substrate, particularly complex carbohydrates that are accessible to bacteria in the colonic ecosystem. However, other factors impact on bacterial metabolism in the large gut, including large bowel transit time, the availability of inorganic terminal electron acceptors, such as nitrate and sulfate, and gut pH. They all affect the types and levels of SCFA that can be formed by the microbiota. This is important because to a large extent, acetate, propionate, and butyrate have varying physiologic effects in different body tissues. Prebiotics such as galactooligosaccharides together with inulins and their fructooligosaccharide derivatives have been shown to modify the species composition of the colonic microbiota, and in various degrees, to manifest several health-promoting properties related to enhanced mineral absorption, laxation, potential anticancer properties, lipid metabolism, and anti-inflammatory and other immune effects, including atopic disease. Many of these phenomena can be linked to their digestion and SCFA production by bacteria in the large gut. PMID:21992950

  1. Discussion of the potential and limitations of direct and large-eddy simulations

    NASA Technical Reports Server (NTRS)

    Hussaini, M. Y.; Speziale, Charles G.; Zang, Thomas A.

    1989-01-01

    The full text of the discussion paper presented at the Whither Turbulence Workshop on the potential and limitations of direct and large-eddy simulations is provided. Particular emphasis is placed on discussing the role of numerics and mathematical theory in direct simulations of both compressible and incompressible flows. A variety of unresolved issues with large-eddy simulations such as their implementation in high-order finite difference codes, problems with defiltering, and modifications to accommodate integrations to solid boundaries are elaborated on. These as well as other points are discussed in detail along with the authors' views concerning the prospects for future research.

  2. Effect of Several Drugs on Gastric Potential Difference in Man

    PubMed Central

    Murray, H. S.; Strottman, M. P.; Cooke, A. R.

    1974-01-01

    Measurement of gastric mucosal potential difference was used to study the effect on the gastric mucosal barrier in six volunteer subjects of several drugs known to provoke ulcers. Potential differences were also recorded in nine patients with rheumatoid arthritis being treated with long-term aspirin and five patients on long-term prednisone. Unbuffered aspirin and ethanol broke the barrier as shown by a rapid fall in potential difference. The effects of aspirin were dose related, with 600 mg causing a greater reduction than 300 mg. The effects of aspirin and ethanol given together were additive and caused the greatest fall in potential difference. Sodium acetylsalicylate did not alter the normal potential difference. Indomethacin, phenylbutazone, and prednisone all failed to cause any change in potential difference. The patients on long-term aspirin and prednisone had readings within the normal range and responded the same as normal subjects to an acute challenge. These studies show that aspirin and ethanol will damage the gastric mucosal barrier but that indomethacin, phenylbutazone, and prednisone do not. PMID:4808815

  3. Floating potential of large dust grains with electron emission

    SciTech Connect

    Bacharis, M.

    2014-07-15

    Electron emission from the surface of solid particles plays an important role in many dusty plasma phenomena and applications. Examples of such cases include fusion plasmas and dusty plasma systems in our solar system. Electron emission complicates the physics of the plasma-dust interaction. One of the most important aspects of the physics of the dust plasma interaction is the calculation of the particle's floating potential. This is the potential a dust particle acquires when it is in contact with a plasma and it plays a very important role for determining its dynamical behaviour. The orbital motion limited (OML) approach is used in most cases in the literature to model the dust charging physics. However, this approach has severe limitations when the size of the particles is larger than the electron Debye length λ{sub De}. Addressing this shortcoming for cases without electron emission, a modified version of OML (MOML) was developed for modelling the charging physics of dust grains larger than the electron Debye length. In this work, we will focus on extending MOML in cases where the particles emit electrons. Furthermore, a general method for calculating the floating potential of dust particles with electron emission will be presented for a range of grain sizes.

  4. Floating potential of large dust grains with electron emission

    NASA Astrophysics Data System (ADS)

    Bacharis, M.

    2014-07-01

    Electron emission from the surface of solid particles plays an important role in many dusty plasma phenomena and applications. Examples of such cases include fusion plasmas and dusty plasma systems in our solar system. Electron emission complicates the physics of the plasma-dust interaction. One of the most important aspects of the physics of the dust plasma interaction is the calculation of the particle's floating potential. This is the potential a dust particle acquires when it is in contact with a plasma and it plays a very important role for determining its dynamical behaviour. The orbital motion limited (OML) approach is used in most cases in the literature to model the dust charging physics. However, this approach has severe limitations when the size of the particles is larger than the electron Debye length ?De. Addressing this shortcoming for cases without electron emission, a modified version of OML (MOML) was developed for modelling the charging physics of dust grains larger than the electron Debye length. In this work, we will focus on extending MOML in cases where the particles emit electrons. Furthermore, a general method for calculating the floating potential of dust particles with electron emission will be presented for a range of grain sizes.

  5. Germination Responses to Water Potential in Neotropical Pioneers Suggest Large-seeded Species Take More Risks

    PubMed Central

    Daws, Matthew I.; Crabtree, Lora M.; Dalling, James W.; Mullins, Christopher E.; Burslem, David F. R. P.

    2008-01-01

    Background and Aims In neotropical forests, very small-seeded pioneer species (<01 mg seed mass) recruit preferentially in small tree fall gaps and at gap edges, but large-seeded pioneers do not. Since water availability is related to gap size, these differences in microsite preference may reflect in part species-specific differences in germination at reduced water potentials. Methods For 14 neotropical pioneer species, the hypothesis is tested that small-seeded species, with shallow initial rooting depths, reduce the risks associated with desiccation by germinating more slowly and at higher water potentials than large-seeded species. Key Results Germination occurred both more quickly and at lower water potentials with increasing seed mass. For example, Ochroma pyramidale (seed mass 55 mg) had a time to 50 % germination (T50) of 28 d and a median base potential for germination (?b50) of ?18 MPa while Clidemia quinquenervia (seed mass 0017 mg) had a T50 of 176 d and ?b50 of ?11 MPa. Conclusions These data suggest that small-seeded species germinate only in comparatively moist microsites, such as small canopy gaps, which may reduce the risk of drought-induced mortality. Conversely, large-seeded species are able to germinate in the drier environment of large gaps, where they benefit by enhanced seedling growth in a high irradiance environment. The positive association of seed size and canopy gap size for optimal seedling establishment is maintained by differential germination responses to soil water availability coupled with the scaling of radicle growth rate and seed size, which collectively confer greater drought tolerance on large-seeded species. PMID:18840874

  6. Large Scale Predictions of Potential Post-fire Erosion

    NASA Astrophysics Data System (ADS)

    Miller, M. E.; MacDonald, L. H.

    2005-12-01

    High-severity wildfires are of increasing concern because of their potential for initiating flash floods and surface erosion, degrading water quality, and reducing reservoir capacity. In many areas fire suppression has increased fuel accumulations and hence the potential for high-severity wildfires. Land management agencies are undertaking programs to reduce fuel loadings and the associated risk of high-severity wildfires, but the areas needing treatment greatly exceed the available funding. It is therefore necessary to determine which areas should have a higher priority for such treatments. Similarly, when wildfires do occur there is an immediate need to determine which areas should have the highest priority for post-fire rehabilitation treatments. One criterion for allocating treatments is the potential risk of post-fire erosion, but to be effective this assessment needs to be carried out at a broad scale. This paper presents a procedure and initial results for predicting spatially-explicit, post-fire erosion risks at the hillslope scale for forest and shrub lands across the western U.S. Our approach utilizes existing physical models and datasets in a GIS framework. The model for predicting erosion is GeoWEPP, the Geographical interface for the Water Erosion Prediction Project (WEPP). The primary inputs for GeoWEPP include climate, topography, soils, and land cover/land use. Daily climate inputs were generated with Cligen, which is a stochastic weather generator distributed with WEPP. A 30-m digital elevation model, STATSGO-derived soils data, and vegetation cover were obtained from the U.S. Forest Service's LANDFIRE project. Since recent research has shown that percent ground cover is a dominant control on post-fire erosion rates, we generated a spatially-explicit map of post-fire ground cover by first using historic weather data to determine the 1000-hr fuel moisture values when fuel conditions were at 98-100% ERC (Energy Released Component). These fuel moisture values were fed into FOFEM (First Order Fire Effects Model) to obtain spatially-explicit predictions of percent ground cover, and this provided the additional land cover/land use information needed by GeoWEPP. The predicted erosion rates are comparable to measured values in the Colorado Front Range, but are much too high for the higher rainfall areas along the Pacific Coast. This pattern indicates that precipitation is having a pre-dominant effect on predicted post-fire erosion rates, especially in areas that are projected to burn at low severity. Hence the predicted erosion rates will be most useful in relative terms at the local and possibly regional scale, while comparisons between regions may be of more limited validity.

  7. Potential for large outbreaks of Ebola virus disease

    PubMed Central

    Camacho, A.; Kucharski, A.J.; Funk, S.; Breman, J.; Piot, P.; Edmunds, W.J.

    2014-01-01

    Outbreaks of Ebola virus can cause substantial morbidity and mortality in affected regions. The largest outbreak of Ebola to date is currently underway in West Africa, with 3944 cases reported as of 5th September 2014. To develop a better understanding of Ebola transmission dynamics, we revisited data from the first known Ebola outbreak, which occurred in 1976 in Zaire (now Democratic Republic of Congo). By fitting a mathematical model to time series stratified by disease onset, outcome and source of infection, we were able to estimate several epidemiological quantities that have previously proved challenging to measure, including the contribution of hospital and community infection to transmission. We found evidence that transmission decreased considerably before the closure of the hospital, suggesting that the decline of the outbreak was most likely the result of changes in host behaviour. Our analysis suggests that the person-to-person reproduction number was 1.34 (95% CI: 0.922.11) in the early part of the outbreak. Using stochastic simulations we demonstrate that the same epidemiological conditions that were present in 1976 could have generated a large outbreak purely by chance. At the same time, the relatively high person-to-person basic reproduction number suggests that Ebola would have been difficult to control through hospital-based infection control measures alone. PMID:25480136

  8. A comparison of different empirical potentials in ZnS

    NASA Astrophysics Data System (ADS)

    Khalkhali, Mohammad; Liu, Qingxia; Zhang, Hao

    2014-12-01

    The accuracy of molecular dynamics simulation highly depends on the reliability of the empirical potential that it uses. Atomistic simulations of ZnS have attracted a lot of attention in the past few decades due to the technological importance of this material as a semiconductor and the main resource of world zinc production. Although multiple empirical potentials have been suggested for ZnS, there is no comprehensive study that compares the performance of these potentials. In this paper, we have reviewed five of the most used ZnS empirical potentials and have tested their performance in predicting different ZnS properties. Based on the obtained results, we provide recommendations for a proper empirical potential based on the application that the molecular mechanic simulation is aiming for.

  9. Evaluation of potential runaway generation in large-tokamak disruptions

    SciTech Connect

    Fleischmann, H.H.; Zweben, S.J. |

    1993-06-01

    A detailed evaluation of various potential mechanisms for the generation of strong runaway beams during disruptions of largetokamak devices, including TFTR, JET, DIIID and ITER, is performed based on typical operating parameters of these devices and the presently accepted disruption model. The main results include: (1) In the existing devices, the evaporative ``preicer`` process by itself can lead to sizable runaway beams in disruptions of high-current-medium-to-low-ne discharges. In ITER, such runaways are expected mainly for discharges with ne values sizably smaller than the projected typical ones. (2) Runaway generation also may occur during post-thermal-quench period through the untrapping of trapped hot-thermal electrons remaining from the pre-thermal-quench plasma; this process may be directly important in particular in disruptions of high-T{sub e} discharges with details depending on the time required for reclosure of the magnetic surfaces. Both processes (1) and (2) will occur and be completed mostly during the initial few 100 {mu}sec after the thermal quench. (3) Subsequently, close collisions of runaways with cold plasma electrons generally will lead to an exponential growth (``avalanching``) of runaway populations generated by processes (1) and/or (2) and/or others; this process will be effective in particular during the current quench phase and will continue until the resulting runaway beam will carry essentially all of the remaining discharge current. In presently existing devices, possible avalanche factors of up to 10{sup 2}--10{sup 5} may be expected; in ITER, avalanche factors of up to 10{sup 10}--10{sup 15} -- if not properly suppressed -- are expected to lead to strong runaway beams in most disruptions, except those at particularly high densities. At the same time, avalanching will shift the main part of their energy spectrum down to relatively low energies around 10--20 MeV, and may sizably change the spatial distribution of the runaways.

  10. Evaluation of potential runaway generation in large-tokamak disruptions

    SciTech Connect

    Fleischmann, H.H.; Zweben, S.J. . Plasma Physics Lab. Cornell Univ., Ithaca, NY . School of Applied and Engineering Physics)

    1993-06-01

    A detailed evaluation of various potential mechanisms for the generation of strong runaway beams during disruptions of largetokamak devices, including TFTR, JET, DIIID and ITER, is performed based on typical operating parameters of these devices and the presently accepted disruption model. The main results include: (1) In the existing devices, the evaporative preicer'' process by itself can lead to sizable runaway beams in disruptions of high-current-medium-to-low-ne discharges. In ITER, such runaways are expected mainly for discharges with ne values sizably smaller than the projected typical ones. (2) Runaway generation also may occur during post-thermal-quench period through the untrapping of trapped hot-thermal electrons remaining from the pre-thermal-quench plasma; this process may be directly important in particular in disruptions of high-T[sub e] discharges with details depending on the time required for reclosure of the magnetic surfaces. Both processes (1) and (2) will occur and be completed mostly during the initial few 100 [mu]sec after the thermal quench. (3) Subsequently, close collisions of runaways with cold plasma electrons generally will lead to an exponential growth ( avalanching'') of runaway populations generated by processes (1) and/or (2) and/or others; this process will be effective in particular during the current quench phase and will continue until the resulting runaway beam will carry essentially all of the remaining discharge current. In presently existing devices, possible avalanche factors of up to 10[sup 2]--10[sup 5] may be expected; in ITER, avalanche factors of up to 10[sup 10]--10[sup 15] -- if not properly suppressed -- are expected to lead to strong runaway beams in most disruptions, except those at particularly high densities. At the same time, avalanching will shift the main part of their energy spectrum down to relatively low energies around 10--20 MeV, and may sizably change the spatial distribution of the runaways.

  11. Liquefaction Potential of Unsaturated Nevada Sand at Different Initial Conditions

    NASA Astrophysics Data System (ADS)

    Xu, Jiting

    It has been tacitly assumed that liquefaction does not occur in unsaturated soils during seismic events, because pore air behaves as a cushion and excess pore water pressure is difficult to accumulate. During recent earthquakes, some slopes composed of unsaturated soils experienced large deformation similar to fluid flow. One explanation for this phenomenon is that the unsaturated slopes completely lost their effective stress and reached a state of liquefaction. The field observation shows controversial phenomenon against current understanding on soil liquefaction. This work was motivated to solve this controversy by experimentally studying the following two questions: 1) are unsaturated soils liquefiable? and 2) how do the initial conditions, including relative density, effective confining pressure, and degree of saturation affect the liquefaction potential of unsaturated soils? To answer the above questions, a series of strain-controlled undrained cyclic loading triaxial tests on saturated and unsaturated Nevada sand were conducted. The index properties studied included particle size distribution, maximum and minimum void ratios, and specific gravity. To provide data for future numerical modeling on unsaturated Nevada sand, hysteretic soil water characteristics curves under different relative densities were also measured. For triaxial tests on saturated Nevada sand, the effects of initial relative density (i.e. Dr=30%, 50%, and 70%) and effective confining pressure (i.e. s'c0 =50 kPa, 100 kPa, and 200 kPa) on soil liquefaction were studied. For unsaturated soil tests, besides initial relative density (Dr=50%) and effective confining pressure ( s'c0 =100 kPa), the effects of initial degree of saturation (S r0=90%, 95%) on liquefaction were also investigated. For saturated Nevada sand, the liquefaction potential decreased with an increase of relative density and effective confining pressure. When the other initial conditions were the same, the cycles needed to make the specimen liquefy increased with the relative density. For the same other initial conditions, the number of cycles required to make the saturated specimen liquefy increased with an increase in the effective confining pressure. For unsaturated Nevada sand, the liquefaction potential generally decreased with an increase in effective confining pressure and an increase in relative density. When the initial degree of saturation was 95%, about 180% and 70% more cycles were needed to reach liquefaction for the loose Nevada sand (Dr=30%) and the dense Nevada sand (Dr=70%), respectively, if the effective confining pressure increased from 50kPa to 200kPa. When the initial degree of saturation was 95% and the effective confining pressure was 50kPa, about 45% more cycles were needed to make the specimen liquefy if the relative density changed from 30% to 50%. When the confining pressure was 200kPa and the degree of saturation was 95%, the relative density did not play a significant role in effecting liquefaction of Nevada sand. For the loose Nevada sand, the liquefaction potential decreased with a decrease in degree of saturation. When the confining pressure was 50kPa and the degree of saturation was 90%, the number of cycles required to liquefy doubled compared to the saturated case. When the effective confining pressure was 200kPa, twice of the number of cycles were needed for the sand to liquefy when the degree of saturation was decreased by 5%. For the dense Nevada sand, the degree of saturation did not play an important role on the number of cycles required to reach liquefaction under lower effective confining pressure (50kPa). However, when the effective confining pressure was increased to 200kPa, the number of cycles for liquefaction was significantly increased with the decreasing degree of saturation. When the degree of saturation was 90%, the 70% relative density specimen experienced 2.0% axial strain without liquefying.

  12. On hemispheric differences in evoked potentials to speech stimuli

    NASA Technical Reports Server (NTRS)

    Galambos, R.; Benson, P.; Smith, T. S.; Schulman-Galambos, C.; Osier, H.

    1975-01-01

    Confirmation is provided for the belief that evoked potentials may reflect differences in hemispheric functioning that are marginal at best. Subjects were right-handed and audiologically normal men and women, and responses were recorded using standard EEG techniques. Subjects were instructed to listen for the targets while laying in a darkened sound booth. Different stimuli, speech and tone signals, were used. Speech sounds were shown to evoke a response pattern that resembles that to tone or clicks. Analysis of variances on peak amplitude and latency measures showed no significant differences between hemispheres, however, a Wilcoxon test showed significant differences in hemispheres for certain target tasks.

  13. Murine and human CFTR exhibit different sensitivities to CFTR potentiators.

    PubMed

    Cui, Guiying; McCarty, Nael A

    2015-10-01

    Development of therapeutic molecules with clinical efficacy as modulators of defective CFTR includes efforts to identify potentiators that can overcome or repair the gating defect in mutant CFTR channels. This has taken a great leap forward with the identification of the potentiator VX-770, now available to patients as "Kalydeco." Other small molecules with different chemical structure also are capable of potentiating the activity of either wild-type or mutant CFTR, suggesting that there are features of the protein that may be targeted to achieve stimulation of channel activity by structurally diverse compounds. However, neither the mechanisms by which these compounds potentiate mutant CFTR nor the site(s) where these compounds bind have been identified. This knowledge gap partly reflects the lack of appropriate experimental models to provide clues toward the identification of binding sites. Here, we have compared the channel behavior and response to novel and known potentiators of human CFTR (hCFTR) and murine (mCFTR) expressed in Xenopus oocytes. Both hCFTR and mCFTR were blocked by GlyH-101 from the extracellular side, but mCFTR activity was increased with GlyH-101 applied directly to the cytoplasmic side. Similarly, glibenclamide only exhibited a blocking effect on hCFTR but both blocked and potentiated mCFTR in excised membrane patches and in intact oocytes. The clinically used CFTR potentiator VX-770 transiently increased hCFTR by ?13% but potentiated mCFTR significantly more strongly. Our results suggest that mCFTR pharmacological sensitivities differ from hCFTR, which will provide a useful tool for identifying the binding sites and mechanism for these potentiators. PMID:26209275

  14. Human intestinal potential difference: recording method and biophysical implications.

    PubMed Central

    Gustke, R F; McCormick, P; Ruppin, H; Soergel, K H; Whalen, G E; Wood, C M

    1981-01-01

    1. The transmural electrical potential difference (PD) of the intact human small intestine was recorded with close attention to electrical symmetry, shielding from electro-magnetic waves and correction for junction potentials. 2. The PD is -12 mV (mucosa-negative) in the fasting jejunum and ileum and does not change during perfusion with isotonic NaCl. 3. Absorption of Na and Cl appears to be non-electrogenic and the 'resting' PD is probably generated by active anion secretion of fasting intestinal contents. 4. Diffusion potentials during isotonic D-mannitol perfusion indicated higher cation selectivity in the ileum than in the jejunum. 5. The calculated contribution of a free-solution path to total paracellular permeability is 55% in the jejunum but only 15% in the ileum. 6. No 'streaming' potential was detected during osmotic water flow, suggesting that the cation-selectivity of the channels is temporarily inactivated during dilatation of the lateral intercellular space. PMID:6802960

  15. Metabolomic Analyses of Leishmania Reveal Multiple Species Differences and Large Differences in Amino Acid Metabolism

    PubMed Central

    Wang, Lijie; Zhang, Tong; Watson, David G.; Silva, Ana Marta; Coombs, Graham H.

    2015-01-01

    Comparative genomic analyses of Leishmania species have revealed relatively minor heterogeneity amongst recognised housekeeping genes and yet the species cause distinct infections and pathogenesis in their mammalian hosts. To gain greater information on the biochemical variation between species, and insights into possible metabolic mechanisms underpinning visceral and cutaneous leishmaniasis, we have undertaken in this study a comparative analysis of the metabolomes of promastigotes of L. donovani, L. major and L. mexicana. The analysis revealed 64 metabolites with confirmed identity differing 3-fold or more between the cell extracts of species, with 161 putatively identified metabolites differing similarly. Analysis of the media from cultures revealed an at least 3-fold difference in use or excretion of 43 metabolites of confirmed identity and 87 putatively identified metabolites that differed to a similar extent. Strikingly large differences were detected in their extent of amino acid use and metabolism, especially for tryptophan, aspartate, arginine and proline. Major pathways of tryptophan and arginine catabolism were shown to be to indole-3-lactate and arginic acid, respectively, which were excreted. The data presented provide clear evidence on the value of global metabolomic analyses in detecting species-specific metabolic features, thus application of this technology should be a major contributor to gaining greater understanding of how pathogens are adapted to infecting their hosts. PMID:26368322

  16. Large and Small Dendritic Spines Serve Different Interacting Functions in Hippocampal Synaptic Plasticity and Homeostasis.

    PubMed

    Paulin, Joshua J W; Haslehurst, Peter; Fellows, Alexander D; Liu, Wenfei; Jackson, Joshua D; Joel, Zelah; Cummings, Damian M; Edwards, Frances A

    2016-01-01

    The laying down of memory requires strong stimulation resulting in specific changes in synaptic strength and corresponding changes in size of dendritic spines. Strong stimuli can also be pathological, causing a homeostatic response, depressing and shrinking the synapse to prevent damage from too much Ca(2+) influx. But do all types of dendritic spines serve both of these apparently opposite functions? Using confocal microscopy in organotypic slices from mice expressing green fluorescent protein in hippocampal neurones, the size of individual spines along sections of dendrite has been tracked in response to application of tetraethylammonium. This strong stimulus would be expected to cause both a protective homeostatic response and long-term potentiation. We report separation of these functions, with spines of different sizes reacting differently to the same strong stimulus. The immediate shrinkage of large spines suggests a homeostatic protective response during the period of potential danger. In CA1, long-lasting growth of small spines subsequently occurs consolidating long-term potentiation but only after the large spines return to their original size. In contrast, small spines do not change in dentate gyrus where potentiation does not occur. The separation in time of these changes allows clear functional differentiation of spines of different sizes. PMID:26881123

  17. Large and Small Dendritic Spines Serve Different Interacting Functions in Hippocampal Synaptic Plasticity and Homeostasis

    PubMed Central

    Paulin, Joshua J. W.; Haslehurst, Peter; Fellows, Alexander D.; Liu, Wenfei; Jackson, Joshua D.; Joel, Zelah; Cummings, Damian M.; Edwards, Frances A.

    2016-01-01

    The laying down of memory requires strong stimulation resulting in specific changes in synaptic strength and corresponding changes in size of dendritic spines. Strong stimuli can also be pathological, causing a homeostatic response, depressing and shrinking the synapse to prevent damage from too much Ca2+ influx. But do all types of dendritic spines serve both of these apparently opposite functions? Using confocal microscopy in organotypic slices from mice expressing green fluorescent protein in hippocampal neurones, the size of individual spines along sections of dendrite has been tracked in response to application of tetraethylammonium. This strong stimulus would be expected to cause both a protective homeostatic response and long-term potentiation. We report separation of these functions, with spines of different sizes reacting differently to the same strong stimulus. The immediate shrinkage of large spines suggests a homeostatic protective response during the period of potential danger. In CA1, long-lasting growth of small spines subsequently occurs consolidating long-term potentiation but only after the large spines return to their original size. In contrast, small spines do not change in dentate gyrus where potentiation does not occur. The separation in time of these changes allows clear functional differentiation of spines of different sizes. PMID:26881123

  18. Scaling differences between large interplate and intraplate earthquakes

    NASA Technical Reports Server (NTRS)

    Scholz, C. H.; Aviles, C. A.; Wesnousky, S. G.

    1985-01-01

    A study of large intraplate earthquakes with well determined source parameters shows that these earthquakes obey a scaling law similar to large interplate earthquakes, in which M sub o varies as L sup 2 or u = alpha L where L is rupture length and u is slip. In contrast to interplate earthquakes, for which alpha approximately equals 1 x .00001, for the intraplate events alpha approximately equals 6 x .0001, which implies that these earthquakes have stress-drops about 6 times higher than interplate events. This result is independent of focal mechanism type. This implies that intraplate faults have a higher frictional strength than plate boundaries, and hence, that faults are velocity or slip weakening in their behavior. This factor may be important in producing the concentrated deformation that creates and maintains plate boundaries.

  19. Sulforaphane Potentiates RNA Damage Induced by Different Xenobiotics

    PubMed Central

    Fimognari, Carmela; Lenzi, Monia; Sestili, Piero; Turrini, Eleonora; Ferruzzi, Lorenzo; Hrelia, Patrizia; Cantelli-Forti, Giorgio

    2012-01-01

    Background The isothiocyanate sulforaphane (SFN) possesses interesting anticancer activities. However, recent studies reported that SFN promotes the formation of reactive oxygen species (ROS) as well as DNA breakage. Methodology/Principal Findings We investigated whether SFN is able to damage RNA, whose loss of integrity was demonstrated in different chronic diseases. Considering the ability of SFN to protect from genotoxicity, we also examined whether SFN is able to protect from RNA damage induced by different chemicals (doxorubicin, spermine, S-nitroso-N-acetylpenicillamine, H2O2). We observed that SFN was devoid of either RNA damaging and RNA protective activity in human leukemic cells. It was able to potentiate the RNA damage by doxorubicin and spermine. In the first case, the effect was attributable to its ability of modulating the bioreductive activation of doxorubicin. For spermine, the effects were mainly due to its modulation of ROS levels produced by spermine metabolism. As to the cytotoxic relevance of the RNA damage, we found that the treatment of cells with a mixture of spermine or doxorubicin plus SFN increased their proapoptotic potential. Thus it is conceivable that the presence of RNA damage might concur to the overall toxic response induced by a chemical agent in targeted cells. Conclusions/Significance Since RNA is emerging as a potential target for anticancer drugs, its ability to enhance spermine- and doxorubicin-induced RNA damage and cytotoxicity could represent an additional mechanism for the potentiating effects of SFN associated with anticancer drugs. PMID:22539965

  20. Reconstruction of the local inflationary potential with different correlation levels

    NASA Astrophysics Data System (ADS)

    Di Marco, A.; Cabella, P.; Vittorio, N.

    2016-02-01

    We review the puzzles of the standard Big Bang model and cosmic inflation as their possible solutions. The relation between inflation and the spectra of the cosmological perturbations is emphasized. In particular we focus on the local reconstruction of the shape of the inflationary potential from observations and the consequences of a direct detection of cosmological gravitational waves, exploring different correlation levels between the spectral index ns and the tensor-to-scalar ratio r of the primordial perturbations.

  1. Betavoltaics using scandium tritide and contact potential difference

    NASA Astrophysics Data System (ADS)

    Liu, Baojun; Chen, Kevin P.; Kherani, Nazir P.; Zukotynski, Stefan; Antoniazzi, Armando B.

    2008-02-01

    Tritium-powered betavoltaic micropower sources using contact potential difference (CPD) are demonstrated. Thermally stable scandium tritide thin films with a surface activity of 15mCi/cm2 were used as the beta particle source. The electrical field created by the work function difference between the ScT film and a platinum or copper electrode was used to separate the beta-generated electrical charge carriers. Open circuit voltages of 0.5 and 0.16V and short circuit current densities of 2.7 and 5.3nA/cm2 were achieved for gaseous and solid dielectric media-based CPD cells, respectively.

  2. OBTAINING POTENTIAL FIELD SOLUTIONS WITH SPHERICAL HARMONICS AND FINITE DIFFERENCES

    SciTech Connect

    Toth, Gabor; Van der Holst, Bart; Huang Zhenguang

    2011-05-10

    Potential magnetic field solutions can be obtained based on the synoptic magnetograms of the Sun. Traditionally, a spherical harmonics decomposition of the magnetogram is used to construct the current- and divergence-free magnetic field solution. This method works reasonably well when the order of spherical harmonics is limited to be small relative to the resolution of the magnetogram, although some artifacts, such as ringing, can arise around sharp features. When the number of spherical harmonics is increased, however, using the raw magnetogram data given on a grid that is uniform in the sine of the latitude coordinate can result in inaccurate and unreliable results, especially in the polar regions close to the Sun. We discuss here two approaches that can mitigate or completely avoid these problems: (1) remeshing the magnetogram onto a grid with uniform resolution in latitude and limiting the highest order of the spherical harmonics to the anti-alias limit; (2) using an iterative finite difference algorithm to solve for the potential field. The naive and the improved numerical solutions are compared for actual magnetograms and the differences are found to be rather dramatic. We made our new Finite Difference Iterative Potential-field Solver (FDIPS) a publicly available code so that other researchers can also use it as an alternative to the spherical harmonics approach.

  3. Large anisotropy difference in the NN? system for ? and ? channels

    NASA Astrophysics Data System (ADS)

    Rappenecker, G.; Rigney, M. M.; van de Wiele, J.; Anton, G.; Arends, J.; Berrier-Ronsin, G.; Blanpied, G.; Breuer, M.; Buechler, K.; Didelez, J. P.; Elayi, A.; Frascaria, R.; Harpes, N.; Hoffmann-Rothe, P.; Hourani, E.; Noeldeke, G.; Preedom, B.; Rosier, L.; Saghai, B.; Zucht, B.

    1995-05-01

    Cross sections and beam asymmetries for the reaction p(p?0)pp have been measured for incident polarized proton energies from the threshold to 1 GeV, and compared with those for the charged pion channels in p(n,?)NN reactions. The observed anisotropy difference around 540 MeV has been ascribed to the 3D1 partial wave contribution to the np initial state. (AIP)

  4. Injury Differences Between Small and Large Overlap Frontal Crashes

    PubMed Central

    Hallman, Jason J.; Yoganandan, Narayan; Pintar, Frank A.; Maiman, Dennis J.

    2011-01-01

    Because small overlap impacts have recently emerged as a crash mode posing great injury risk to occupants, a detailed analysis of US crash data was conducted using the NASS/CDS and CIREN databases. Frontal crashes were subcategorized into small overlap impact (SOI) and large overlap impact (LOI) using crash and crush characteristics from the datasets. Injuries to head, spine, chest, hip and pelvis, and lower extremities were parsed and compared between crash types. MAIS 3+ occupants in NASS/CDS and CIREN demonstrated increased incidence of head, chest, spine, and hip/pelvis injuries in SOI compared to LOI. In NASS/CDS, subgaleal hematoma represented 48.6% of SOI head injury codes but 27.6% in LOI. Cervical spine posterior element fractures also represented greater proportions of SOI spine injuries (e.g., facet fractures: 27.8 vs. 14.0%), and proximal femur fractures represented a greater proportion of hip/pelvis injuries (e.g., intertrochanteric fracture: 32.5 vs. 11.8%). Tarsal/metatarsal fractures were a lesser proportion of lower extremity injuries in SOI compared to LOI. Occupant contact points inducing these injuries were observed in CIREN cases in some instances without compartment intrusion. These injuries suggest the substantial role of occupant kinematics in SOI which may induce suboptimal occupant restraint interaction. PMID:22105392

  5. Separation of large mammalian ventricular myosin differing in ATPase activity.

    PubMed

    Rupp, Heinz; Maisch, Bernhard

    2007-01-01

    To investigate a possible heterogeneity of human ventricular myosin, papillary muscles of patients with valvular dysfunction were examined using a modified native gel electrophoresis. Myosin was separated into 2 components termed VA and VB, whereby the VA to VB proportion appeared to depend on the ventricular load. The proportion of the faster migrating band VA was correlated (P<0.05) with end-diastolic pressure and the aortic pressure-cardiac index product. The regression based on these variables accounted for 67% of the variation in VA (R2=0.67). The VA proportion was, however, not significantly correlated with cardiac norepinephrine concentration. The ATPase activity of the 2 components of myosin was assessed from the Ca3(PO4)2 precipitation by incubating the gel in the presence of ATP and CaCl2. The ATPase activity of VA was 60% of that of VB. The VA and VB forms were observed also in the cat (31.4% VA), dog (32.1% VA), pig (28.5% VA), wild pig (33.7% VA), and roe deer (30.5% VA). VA and VB were not detected in the rat exhibiting the 3 isoforms V1, V2, and V3, rabbit (100% V3), and hare (86% V1). The data demonstrate a heterogeneity of large mammalian ventricular myosin, whereby an increased cardiac load appeared to be associated with a higher myosin VA proportion that exhibited a reduced ATPase activity. PMID:17612641

  6. Correlation of variations in intraluminal pressure and potential differences in the perfused colen.

    PubMed Central

    Postaire, J G; Gerard, J; Devroede, G; Van Houtte, N

    1977-01-01

    To investigate the nature of variations in the large intestine potential differences, a continuous perfusion of isotonic saline was carried out in the colon of 14 rats. Intraluminal pressure and potential differences between the lumen and the peritoneal cavity were continuously and simultaneously recorded, while impedance of the system and respiration were also constantly monitored. To obtain a quantitative evaluation of the data, Fast Fouier Transform was performed on the signals and their derivatives which were auto- and cross-correlated. While there was no obvious relation between pressure and potential in the unperfused colon, there was clear visual qualirative evidence that, during steady state conditions of perfusion, an increase in intraluminal pressure was accompanied by a decrease in potential differences, while impedance of the recording system remained unchanged. Computer analysis disclosed four narrow ranges of stable frequencies for both pressure and potential. They were centred around 0-3, 1-75, 10-7, and 75 cycles per minute, the latter being synchronous with respiration. It is concluded that the variations of potential differences recorded during perfusion, a well-know phenomenon, are not electrical artefacts: the fast rhythm is probably induced by respiration, which increases intracolonic pressure and that, in turn, reduces the absolute value of potential differences, which remain negative mucosa versus serosa. The slower rhythms are synchronous for pressure and potential. Mechanisms responsible for the decrease in potential related to the increase in pressure remain unknown. PMID:590835

  7. The radiative forcing potential of different climate geoengineering options

    NASA Astrophysics Data System (ADS)

    Lenton, T. M.; Vaughan, N. E.

    2009-08-01

    Climate geoengineering proposals seek to rectify the Earth's current and potential future radiative imbalance, either by reducing the absorption of incoming solar (shortwave) radiation, or by removing CO2 from the atmosphere and transferring it to long-lived reservoirs, thus increasing outgoing longwave radiation. A fundamental criterion for evaluating geoengineering options is their climate cooling effectiveness, which we quantify here in terms of radiative forcing potential. We use a simple analytical approach, based on energy balance considerations and pulse response functions for the decay of CO2 perturbations. This aids transparency compared to calculations with complex numerical models, but is not intended to be definitive. It allows us to compare the relative effectiveness of a range of proposals. We consider geoengineering options as additional to large reductions in CO2 emissions. By 2050, some land carbon cycle geoengineering options could be of comparable magnitude to mitigation "wedges", but only stratospheric aerosol injections, albedo enhancement of marine stratocumulus clouds, or sunshades in space have the potential to cool the climate back toward its pre-industrial state. Strong mitigation, combined with global-scale air capture and storage, afforestation, and bio-char production, i.e. enhanced CO2 sinks, might be able to bring CO2 back to its pre-industrial level by 2100, thus removing the need for other geoengineering. Alternatively, strong mitigation stabilising CO2 at 500 ppm, combined with geoengineered increases in the albedo of marine stratiform clouds, grasslands, croplands and human settlements might achieve a patchy cancellation of radiative forcing. Ocean fertilisation options are only worthwhile if sustained on a millennial timescale and phosphorus addition may have greater long-term potential than iron or nitrogen fertilisation. Enhancing ocean upwelling or downwelling have trivial effects on any meaningful timescale. Our approach provides a common framework for the evaluation of climate geoengineering proposals, and our results should help inform the prioritisation of further research into them.

  8. Linear polarization difference imaging and its potential applications.

    PubMed

    Nan, Zeng; Xiaoyu, Jiang; Qiang, Gao; Yonghong, He; Hui, Ma

    2009-12-10

    We demonstrate a novel linear polarization imaging technique and its potential application in dermatology. This technique records a series of images corresponding to different combinations of illumination and detection polarization and calculates intensity differences between orthogonal detection polarizations pixel by pixel. Fitting the polarization difference data to an analytical expression of the incident and detection polarization angles results in two new parameters, G and (phi3)/2. It is shown that G is strongly correlated to the order of alignment of the fibrous structure in the sample, and (phi3)/2 represents the angle of orientation of the fibers. Preliminary clinical testing implies that this method may be applied for medical diagnosis of skin diseases. PMID:20011013

  9. The potential for sexually antagonistic polymorphism in different genome regions.

    PubMed

    Jordan, Crispin Y; Charlesworth, Deborah

    2012-02-01

    Sex differences in the fitness effects of alleles at a single locus (intralocus sexual antagonism, or SA) have several evolutionary consequences. Among the consequences of SA, polymorphisms at genes partially linked to the sex-determining region of the sex chromosome pair potentially drive the evolution of suppressed recombination between the sex chromosomes. Understanding the conditions under which SA polymorphism can exist at such pseudo-autosomal (or PAR) loci should increase understanding of the evolution of recombination between sex chromosome pairs, and can help predict when we may expect potentially empirically detectable allele frequency differences between the sexes. Models so far published have concluded that PAR genes can maintain SA polymorphisms over a wider range of selection coefficients than autosomal ones, but have used restrictive assumptions. We expand the modeling of SA alleles at a single locus with the full range of degrees of linkage to the male-specific region, to include strong or weak selection and the possibility of different dominance coefficients in the two sexes. We confirm the previous major conclusion that SA polymorphisms are generally maintained in a larger region of parameter space if the locus is in the PAR than if it is autosomal. PMID:22276544

  10. Kinematic morphology of large-scale structure: evolution from potential to rotational flow

    SciTech Connect

    Wang, Xin; Szalay, Alex; Aragón-Calvo, Miguel A.; Neyrinck, Mark C.; Eyink, Gregory L.

    2014-09-20

    As an alternative way to describe the cosmological velocity field, we discuss the evolution of rotational invariants constructed from the velocity gradient tensor. Compared with the traditional divergence-vorticity decomposition, these invariants, defined as coefficients of the characteristic equation of the velocity gradient tensor, enable a complete classification of all possible flow patterns in the dark-matter comoving frame, including both potential and vortical flows. We show that this tool, first introduced in turbulence two decades ago, is very useful for understanding the evolution of the cosmic web structure, and in classifying its morphology. Before shell crossing, different categories of potential flow are highly associated with the cosmic web structure because of the coherent evolution of density and velocity. This correspondence is even preserved at some level when vorticity is generated after shell crossing. The evolution from the potential to vortical flow can be traced continuously by these invariants. With the help of this tool, we show that the vorticity is generated in a particular way that is highly correlated with the large-scale structure. This includes a distinct spatial distribution and different types of alignment between the cosmic web and vorticity direction for various vortical flows. Incorporating shell crossing into closed dynamical systems is highly non-trivial, but we propose a possible statistical explanation for some of the phenomena relating to the internal structure of the three-dimensional invariant space.

  11. Kinematic Morphology of Large-scale Structure: Evolution from Potential to Rotational Flow

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Szalay, Alex; Aragón-Calvo, Miguel A.; Neyrinck, Mark C.; Eyink, Gregory L.

    2014-09-01

    As an alternative way to describe the cosmological velocity field, we discuss the evolution of rotational invariants constructed from the velocity gradient tensor. Compared with the traditional divergence-vorticity decomposition, these invariants, defined as coefficients of the characteristic equation of the velocity gradient tensor, enable a complete classification of all possible flow patterns in the dark-matter comoving frame, including both potential and vortical flows. We show that this tool, first introduced in turbulence two decades ago, is very useful for understanding the evolution of the cosmic web structure, and in classifying its morphology. Before shell crossing, different categories of potential flow are highly associated with the cosmic web structure because of the coherent evolution of density and velocity. This correspondence is even preserved at some level when vorticity is generated after shell crossing. The evolution from the potential to vortical flow can be traced continuously by these invariants. With the help of this tool, we show that the vorticity is generated in a particular way that is highly correlated with the large-scale structure. This includes a distinct spatial distribution and different types of alignment between the cosmic web and vorticity direction for various vortical flows. Incorporating shell crossing into closed dynamical systems is highly non-trivial, but we propose a possible statistical explanation for some of the phenomena relating to the internal structure of the three-dimensional invariant space.

  12. Kinematic Morphology of Large-scale Structure: Evolution from Potential to Rotational Flow

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Szalay, A. S.; Aragon-Calvo, M. A.; Neyrinck, M. C.; Eyink, G. L.

    2014-01-01

    As an alternative way of describing the cosmological velocity field, we discuss the evolution of rotational invariants constructed from the velocity gradient tensor. Compared with the traditional divergence-vorticity decomposition, these invariants, defined as coefficients of characteristic equation of the velocity gradient tensor, enable a complete classification of all possible flow patterns in the dark-matter comoving frame, including both potential and vortical flows. Before shell-crossing, different categories of potential flow are highly associated with cosmic web structure, because of the coherent evolution of density and velocity. This correspondence is even preserved at some level when vorticity is generated after shell-crossing. The evolution from the potential to vortical flow can be traced continuously by these invariants. With the help of this tool, we show that the vorticity is generated in a particular way that is highly correlated with the large-scale structure. This includes a distinct spatial distribution and different types of alignment between cosmic web and vorticity direction for various vortical flows. Incorporating shell-crossing into closed dynamical systems is highly non-trivial, but we propose a possible statistical explanation for some of these phenomena relating to the internal structure of the three-dimensional invariants space.

  13. The radiative forcing potential of different climate geoengineering options

    NASA Astrophysics Data System (ADS)

    Lenton, T. M.; Vaughan, N. E.

    2009-01-01

    Climate geoengineering proposals seek to rectify the Earth's current radiative imbalance, either by reducing the absorption of incoming solar (shortwave) radiation, or by removing CO2 from the atmosphere and transferring it to long-lived reservoirs, thus increasing outgoing longwave radiation. A fundamental criterion for evaluating geoengineering options is their climate cooling effectiveness, which we quantify here in terms of radiative forcing potential. We use a simple analytical approach, based on the global energy balance and pulse response functions for the decay of CO2 perturbations. This aids transparency compared to calculations with complex numerical models, but is not intended to be definitive. Already it reveals some significant errors in existing calculations, and it allows us to compare the relative effectiveness of a range of proposals. By 2050, only stratospheric aerosol injections or sunshades in space have the potential to cool the climate back toward its pre-industrial state, but some land carbon cycle geoengineering options are of comparable magnitude to mitigation "wedges". Strong mitigation, i.e. large reductions in CO2 emissions, combined with global-scale air capture and storage, afforestation, and bio-char production, i.e. enhanced CO2 sinks, might be able to bring CO2 back to its pre-industrial level by 2100, thus removing the need for other geoengineering. Alternatively, strong mitigation stabilising CO2 at 500 ppm, combined with geoengineered increases in the albedo of marine stratiform clouds, grasslands, croplands and human settlements might achieve a patchy cancellation of radiative forcing. Ocean fertilisation options are only worthwhile if sustained on a millennial timescale and phosphorus addition probably has greater long-term potential than iron or nitrogen fertilisation. Enhancing ocean upwelling or downwelling have trivial effects on any meaningful timescale. Our approach provides a common framework for the evaluation of climate geoengineering proposals, and our results should help inform the prioritisation of further research into them.

  14. Estimating Large-Customer Demand Response Market Potential:Integrating Price and Customer Behavior

    SciTech Connect

    Goldman, Charles; Hopper, Nicole; Bharvirkar, Ranjit; Neenan,Bernie; Cappers, Peter

    2007-06-01

    ABSTRACT=Demand response (DR) is increasingly recognized asan essential ingredient to well-functioning electricity markets. DRmarket potential studies can answer questions about the amount of DRavailable in a given area, from which market segments. Several recent DRmarket potential studies have been conducted, most adapting techniquesused to estimate energy-efficiency (EE) potential. In this scoping study,we: reviewed and categorized seven recent DR market potential studies;recommended a methodology for estimating DR market potential for large,non-residential utility customers that uses price elasticities to accountfor behavior and prices; compiled participation rates and elasticityvalues from six DR options offered to large customers in recent years,and demonstrated our recommended methodology with large customer marketpotential scenarios at an illustrative Northeastern utility. We recommendan elasticity approach for large-customer DR options that rely oncusto!

  15. Nasal Potential Difference in Cystic Fibrosis considering Severe CFTR Mutations

    PubMed Central

    Ng, Ronny Tah Yen; Marson, Fernando Augusto de Lima; Ribeiro, Jose Dirceu; Ribeiro, Antonio Fernando; Bertuzzo, Carmen Silvia; Ribeiro, Maria Angela Gonalves de Oliveira; Severino, Silvana Dalge; Sakano, Eulalia

    2015-01-01

    The gold standard for diagnosing cystic fibrosis (CF) is a sweat chloride value above 60?mEq/L. However, this historical and important tool has limitations; other techniques should be studied, including the nasal potential difference (NPD) test. CFTR gene sequencing can identify CFTR mutations, but this method is time-consuming and too expensive to be used in all CF centers. The present study compared CF patients with two classes I-III CFTR mutations (10 patients) (G1), CF patients with classes IV-VI CFTR mutations (five patients) (G2), and 21 healthy subjects (G3). The CF patients and healthy subjects also underwent the NPD test. A statistical analysis was performed using the Mann-Whitney, Kruskal-Wallis, ?2, and Fisher's exact tests, ? = 0.05. No differences were observed between the CF patients and healthy controls for the PDMax, ?amiloride, and ?chloride + free + amiloride markers from the NPD test. For the finger value, a difference between G2 and G3 was described. The Wilschanski index values were different between G1 and G3. In conclusion, our data showed that NPD is useful for CF diagnosis when classes I-III CFTR mutations are screened. However, if classes IV-VI are considered, the NPD test showed an overlap in values with healthy subjects. PMID:25667564

  16. Potential climatic impacts and reliability of large-scale offshore wind farms

    NASA Astrophysics Data System (ADS)

    Wang, Chien; Prinn, Ronald G.

    2011-04-01

    The vast availability of wind power has fueled substantial interest in this renewable energy source as a potential near-zero greenhouse gas emission technology for meeting future world energy needs while addressing the climate change issue. However, in order to provide even a fraction of the estimated future energy needs, a large-scale deployment of wind turbines (several million) is required. The consequent environmental impacts, and the inherent reliability of such a large-scale usage of intermittent wind power would have to be carefully assessed, in addition to the need to lower the high current unit wind power costs. Our previous study (Wang and Prinn 2010 Atmos. Chem. Phys. 10 2053) using a three-dimensional climate model suggested that a large deployment of wind turbines over land to meet about 10% of predicted world energy needs in 2100 could lead to a significant temperature increase in the lower atmosphere over the installed regions. A global-scale perturbation to the general circulation patterns as well as to the cloud and precipitation distribution was also predicted. In the later study reported here, we conducted a set of six additional model simulations using an improved climate model to further address the potential environmental and intermittency issues of large-scale deployment of offshore wind turbines for differing installation areas and spatial densities. In contrast to the previous land installation results, the offshore wind turbine installations are found to cause a surface cooling over the installed offshore regions. This cooling is due principally to the enhanced latent heat flux from the sea surface to lower atmosphere, driven by an increase in turbulent mixing caused by the wind turbines which was not entirely offset by the concurrent reduction of mean wind kinetic energy. We found that the perturbation of the large-scale deployment of offshore wind turbines to the global climate is relatively small compared to the case of land-based installations. However, the intermittency caused by the significant seasonal wind variations over several major offshore sites is substantial, and demands further options to ensure the reliability of large-scale offshore wind power. The method that we used to simulate the offshore wind turbine effect on the lower atmosphere involved simply increasing the ocean surface drag coefficient. While this method is consistent with several detailed fine-scale simulations of wind turbines, it still needs further study to ensure its validity. New field observations of actual wind turbine arrays are definitely required to provide ultimate validation of the model predictions presented here.

  17. Gender differences in chemosensory perception and event-related potentials.

    PubMed

    Olofsson, Jonas K; Nordin, Steven

    2004-09-01

    The present study investigated chemosensory gender differences by means of ratings of total nasal chemosensory intensity, unpleasantness and sensory irritation and simultaneous recordings of chemosensory event-related potentials (CSERPs) for three concentrations of the olfactory/trigeminal stimulus pyridine in 19 women and 17 men, all young adults. Results show that, compared to men, women gave higher intensity and unpleasantness ratings, in particular for the highest stimulus concentration. The gender differences in perceived intensity are reflected in the signal-to-noise ratio of the individual CSERP averages, revealing more identifiable early components (P1, N1) in women than in men. The late positive component, labeled P2/P3, displayed larger amplitudes at all electrode sites and shorter latencies at Cz, in women compared to men. The effects of increased pyridine concentration on perception (larger in women) and CSERPs (similar across gender) imply that the two measures involve partially different neural processing. CSERP component identifiability is proposed here as a general means of assessing signal-to-noise ratio of the CSERPs. PMID:15337687

  18. Potential theory for shock reflection by a large-angle wedge

    PubMed Central

    Chen, Gui-Qiang; Feldman, Mikhail

    2005-01-01

    When a plane shock hits a wedge head on, it experiences a reflection, and then a self-similar reflected shock moves outward as the original shock moves forward in time. Experimental, computational, and asymptotic analysis has shown that various patterns of reflected shocks may occur, including regular and Mach reflection. However, most fundamental issues for shock reflection phenomena have not been understood, such as the transition among the different patterns of shock reflection; therefore, it is essential to establish a global existence and stability theory for shock reflection. On the other hand, there has been no rigorous mathematical result on the global existence and stability of solutions to shock reflection, especially for potential flow, which has widely been used in aerodynamics. The theoretical problems involve several challenging difficulties in the analysis of nonlinear partial differential equations including elliptic-hyperbolic mixed type, free-boundary problems, and corner singularity, especially when an elliptic degenerate curve meets a free boundary. Here we develop a potential theory to overcome these difficulties and to establish the global existence and stability of solutions to shock reflection by a large-angle wedge for potential flow. The techniques and ideas developed will be useful to other nonlinear problems involving similar difficulties. PMID:16230619

  19. The potential of large studies for building genetic risk prediction models

    Cancer.gov

    Posted on March 04, 2013 NCI scientists have developed a new paradigm to assess hereditary risk prediction in common diseases, such as prostate cancer. Researchers assessed the potential of using very large, genome-wide association studies (GWAS) to

  20. Aroma potential of Brancellao grapes from different cluster positions.

    PubMed

    Noguerol-Pato, R; Gonzlez-Barreiro, C; Cancho-Grande, B; Santiago, J L; Martnez, M C; Simal-Gndara, J

    2012-05-01

    In this study the presence of aroma compounds in grapes of Brancellao (Vitis vinifera L.) was investigated in order to obtain its aroma potential fingerprint. It is well known that differences exist in aromatic compounds amongst grapevine varieties at ripening stages. Within the framework of an increasingly competitive market, the chance of obtaining different wines from vines of the same variety grown at the same vineyard is becoming of increasing importance. This can be done through the managing of the vineyard, but also some wineries have assayed the separation of the tip and shoulder berries of the clusters of a specific variety with this objective. In this work it is evaluated that, in the final stages of maturation, differences exist in the probable alcoholic degree, total acidity of the must, as well as in the aromatic composition of skin and flesh of berries coming from the tips and shoulders of the clusters. Gas chromatography coupled to mass spectrometry (GC-MS) was used to determine the aromatic composition, in the skin and flesh of each sample, either tip or shoulder berries from the clusters. The obtained results showed that there was not variability for the probable alcoholic degree and total acidity between the shoulders and tips, whereas there was variability for their aromatic composition. For the berries from the tips of the clusters most of volatiles were found in the flesh (except aldehydes) and spicy and floral nuances (with the only exception of ?-ionone) were in higher proportions. For the berries from the shoulders of the clusters, most of volatiles were found in the skin (monoterpenes, norisoprenoids, aldehydes, and C6 alcohols), where the flesh was slightly richer in aromatic alcohols, volatile phenols and pantolactone; ?-ionone and herbaceous nuances were in higher proportions. These results are promising for those wineries that are considering the chance of separating berries from tips and shoulders of the clusters for the elaboration of different quality wines. PMID:26434270

  1. Pre-anthesis ovary development determines genotypic differences in potential kernel weight in sorghum

    PubMed Central

    Yang, Zongjian; van Oosterom, Erik J.; Jordan, David R.; Hammer, Graeme L.

    2009-01-01

    Kernel weight is an important factor determining grain yield and nutritional quality in sorghum, yet the developmental processes underlying the genotypic differences in potential kernel weight remain unclear. The aim of this study was to determine the stage in development at which genetic effects on potential kernel weight were realized, and to investigate the developmental mechanisms by which potential kernel weight is controlled in sorghum. Kernel development was studied in two field experiments with five genotypes known to differ in kernel weight at maturity. Pre-fertilization floret and ovary development was examined and post-fertilization kernel-filling characteristics were analysed. Large kernels had a higher rate of kernel filling and contained more endosperm cells and starch granules than normal-sized kernels. Genotypic differences in kernel development appeared before stamen primordia initiation in the developing florets, with sessile spikelets of large-seeded genotypes having larger floret apical meristems than normal-seeded genotypes. At anthesis, the ovaries for large-sized kernels were larger in volume, with more cells per layer and more vascular bundles in the ovary wall. Across experiments and genotypes, there was a significant positive correlation between kernel dry weight at maturity and ovary volume at anthesis. Genotypic effects on meristem size, ovary volume, and kernel weight were all consistent with additive genetic control, suggesting that they were causally related. The pre-fertilization genetic control of kernel weight probably operated through the developing pericarp, which is derived from the ovary wall and potentially constrains kernel expansion. PMID:19228817

  2. Effect of psychological stress on gastric potential difference in man.

    PubMed

    Bergmann, J F; Caulin, C; Genève, J; Simoneau, G; Segrestaa, J M

    1991-01-01

    This study investigated the effect of three different mental stress tests on gastric transmucosal electric potential difference (GPD). GPD measurement was carried out in six healthy volunteers using the agar-KCl bridges method during dichotomous listening, the ringing of a telephone and 90 dB noise. Cardiac, pulmonary and psychological responses to stress were evaluated at the same time. During the stress period, two of the subjects had no change in GPD as well as no extragastric modification due to the stressor. The four other volunteers had a significant stress-induced fall in GPD (12.5 + 5.6 mV) with a simultaneous acceleration of heart and respiration rates and an increase in systolic blood pressure and anxiety feelings which were evaluated on a visual scale. Such mental stress, possibly mediated by autonomous nervous system, may cause some gastric mucosa changes inducing the retrodiffusion of H+ ions and a fall in GPD. This model could be useful in therapeutic research into the prevention and treatment of stress-induced gastric lesions. PMID:1883035

  3. Chiral symmetry restoration at large chemical potential in strongly coupled SU(N) gauge theories

    SciTech Connect

    Tomboulis, E. T.

    2013-12-15

    We show that at sufficiently large chemical potential SU(N) lattice gauge theories in the strong coupling limit with staggered fermions are in a chirally symmetric phase. The proof employs a polymer cluster expansion which exploits the anisotropy between timelike and spacelike directions in the presence of a quark chemical potential ?. The expansion is shown to converge in the infinite volume limit at any temperature for sufficiently large ?. All expectations of chirally non-invariant local fermion operators vanish identically, or, equivalently, their correlations cluster exponentially, within the expansion. The expansion itself may serve as a computational tool at large ? and strong coupling.

  4. Biomass Potentials in Different Maintenance Scenarios of Satoyama Woodlands

    NASA Astrophysics Data System (ADS)

    Terada, T.

    2012-04-01

    Woodlands near human settlements often have long histories of providing people with fuelwood and other organic materials. In Japan, these woodlands are called satoyama. While satoyama woodlands were historically coppiced to provide an essential source of fuelwood, many have been developed into residential areas as a result of the introduction of fossil fuels beginning in the 1960's. Remaining satoyamas were simply abandoned due to the loss of economic value from fuelwood. This has resulted in a loss of other satoyama-related functions such as their ecological function. In response to the abandonment of satoyamas, thousands of volunteer groups have formed since the 1990's to restore satoyama woodlands. However, in spite of the importance of grassroots volunteers, their actual activities are limited in spatial extent due to shortages of manpower, time, and maintenance skill. This suggests that more substantial incentives are necessary, if maintenance of satoyama woodlands is to be extended. This study focused on an increased attention of biomass enegy utilization from satoyama trees as a promising incentive, and estimated biomass potentials in different maintenance scenarios of satoyama woodlands through a case study site in peri-urban Tokyo. This study set four maintenance scenarios; a) ground cover removal, b) light-thinning, c) intensive-thinning, and d) rotational coppicing. Based on the scenarios, the amount of biomass obtained, bioenergy generated, and carbon reduced were estimated respectively by the combination of conducting tree measurement and applying a long-term forest dynamics estimation model. Since there is tradeoff between CO2 reduction through woodenergy utilization and CO2 fixation by standing trees, these two variables were analyzed in tandem. The scenario that produces the most woody biomass was rotational coppicing, the maintenance scenario which also mimics historical management regimes. Despite the lowest potential of CO2 fixation by standing trees, the best scenario to reduce carbon was also rotational coppicing, due to the highest potential of CO2 reduction by woodenergy utilization. The result suggests that rotational coppicing, which mimics historical management, can also serve contemporary ends. Rotational coppicing can be promoted from the policies related to carbon reduction, but at the same time, further studies for clarifying the optimum degree of human disturbance (e.g. frequency of tree cutting, groundcover removal) are necessary to avoid negative impacts to forest ecosystems.

  5. Cryptococcus strains with different pathogenic potentials have diverse protein secretomes.

    PubMed

    Campbell, Leona T; Simonin, Anna R; Chen, Cuilan; Ferdous, Jannatul; Padula, Matthew P; Harry, Elizabeth; Hofer, Markus; Campbell, Iain L; Carter, Dee A

    2015-06-01

    Secreted proteins are the frontline between the host and pathogen. In mammalian hosts, secreted proteins enable invasive infection and can modulate the host immune response. Cryptococcosis, caused by pathogenic Cryptococcus species, begins when inhaled infectious propagules establish to produce pulmonary infection, which, if not resolved, can disseminate to the central nervous system to cause meningoencephalitis. Strains of Cryptococcus species differ in their capacity to cause disease, and the mechanisms underlying this are not well understood. To investigate the role of secreted proteins in disease, we determined the secretome for three genome strains of Cryptococcus species, including a hypovirulent and a hypervirulent strain of C. gattii and a virulent strain of C. neoformans. Sixty-seven unique proteins were identified, with different numbers and types of proteins secreted by each strain. The secretomes of the virulent strains were largely limited to proteolytic and hydrolytic enzymes, while the hypovirulent strain had a diverse secretome, including non-conventionally secreted canonical cytosolic and immunogenic proteins that have been implicated in virulence. The hypovirulent strain cannot establish pulmonary infection in a mouse model, but strains of this genotype have caused human meningitis. To directly test brain infection, we used intracranial inoculation and found that the hypovirulent strain was substantially more invasive than its hypervirulent counterpart. We suggest that immunogenic proteins secreted by this strain invoke a host response that limits pulmonary infection but that there can be invasive growth and damage if infection reaches the brain. Given their known role in virulence, it is possible that non-conventionally secreted proteins mediate this process. PMID:25841021

  6. Cryptococcus Strains with Different Pathogenic Potentials Have Diverse Protein Secretomes

    PubMed Central

    Campbell, Leona T.; Simonin, Anna R.; Chen, Cuilan; Ferdous, Jannatul; Padula, Matthew P.; Harry, Elizabeth; Hofer, Markus; Campbell, Iain L.

    2015-01-01

    Secreted proteins are the frontline between the host and pathogen. In mammalian hosts, secreted proteins enable invasive infection and can modulate the host immune response. Cryptococcosis, caused by pathogenic Cryptococcus species, begins when inhaled infectious propagules establish to produce pulmonary infection, which, if not resolved, can disseminate to the central nervous system to cause meningoencephalitis. Strains of Cryptococcus species differ in their capacity to cause disease, and the mechanisms underlying this are not well understood. To investigate the role of secreted proteins in disease, we determined the secretome for three genome strains of Cryptococcus species, including a hypovirulent and a hypervirulent strain of C. gattii and a virulent strain of C. neoformans. Sixty-seven unique proteins were identified, with different numbers and types of proteins secreted by each strain. The secretomes of the virulent strains were largely limited to proteolytic and hydrolytic enzymes, while the hypovirulent strain had a diverse secretome, including non-conventionally secreted canonical cytosolic and immunogenic proteins that have been implicated in virulence. The hypovirulent strain cannot establish pulmonary infection in a mouse model, but strains of this genotype have caused human meningitis. To directly test brain infection, we used intracranial inoculation and found that the hypovirulent strain was substantially more invasive than its hypervirulent counterpart. We suggest that immunogenic proteins secreted by this strain invoke a host response that limits pulmonary infection but that there can be invasive growth and damage if infection reaches the brain. Given their known role in virulence, it is possible that non-conventionally secreted proteins mediate this process. PMID:25841021

  7. Potential effects of large linear pipeline construction on soil and vegetation in ecologically fragile regions.

    PubMed

    Xiao, Jun; Wang, Ya-Feng; Shi, Peng; Yang, Lei; Chen, Li-Ding

    2014-11-01

    Long-distance pipeline construction results in marked human disturbance of the regional ecosystem and brings into question the safety of pipeline construction with respect to the environment. Thus, the direct environmental impact and proper handling of such large projects have received much attention. The potential environmental effects, however, have not been fully addressed, particularly for large linear pipeline projects, and the threshold of such effects is unclear. In this study, two typical eco-fragile areas in western China, where large linear construction projects have been conducted, were chosen as the case study areas. Soil quality indices (SQI) and vegetation indices (VI), representing the most important potential effects, were used to analyze the scope of the effect of large pipeline construction on the surrounding environment. These two indices in different buffer zones along the pipeline were compared against the background values. The analysis resulted in three main findings. First, pipeline construction continues to influence the nearby eco-environment even after a 4-year recovery period. During this period, the effect on vegetation due to pipeline construction reaches 300 m beyond the working area, and is much larger in distance than the effect on soil, which is mainly confined to within 30 m either side of the pipeline, indicating that vegetation is more sensitive than soil to this type of human disturbance. However, the effect may not reach beyond 500 m from the pipeline. Second, the scope of the effect in terms of distance on vegetation may also be determined by the frequency of disturbance and the intensity of the pipeline construction. The greater the number of pipelines in an area, the higher the construction intensity and the more frequent the disturbance. Frequent disturbance may expand the effect on vegetation on both sides of the pipeline, but not on soil quality. Third, the construction may eliminate the stable, resident plant community. During the recovery period, the plant community in the work area of the pipeline is replaced by some species that are rare or uncommon in the resident plant community because of human disturbance, thereby increasing the plant diversity in the work area. In terms of plant succession, the duration of the recovery period has a direct effect on the composition and structure of the plant community. The findings provide a theoretical basis and scientific foundation for improving the environmental impact assessment (EIA) of oil and gas pipeline construction as it pertains to the desert steppe ecosystem, and provide a reference point for recovery and management of the eco-environment during the pipeline construction period. PMID:25112841

  8. Influence of perfusate temperature on nasal potential difference.

    PubMed

    Bronsveld, Inez; Vermeulen, Franois; Sands, Dorotha; Leal, Teresinha; Leonard, Anissa; Melotti, Paola; Yaakov, Yasmin; de Nooijer, Roel; De Boeck, Kris; Sermet, Isabelle; Wilschanski, Michael; Middleton, Peter G

    2013-08-01

    Nasal potential difference (NPD) quantifies abnormal ion transport in cystic fibrosis. It has gained acceptance as an outcome measure for the investigation of new therapies. To quantify the effect of solution temperature on NPD, we first examined the effect of switching from room temperature (20-25C) to warmed (32-37C) solutions and vice versa during each perfusion step. Secondly, standard protocols were repeated at both temperatures in the same subjects. Changing solution temperature did not alter NPD during perfusion with Ringer's solution (<1 mV) (p>0.1). During perfusion with zero chloride solution, changing from room temperature to warmed solutions tended to decrease absolute NPD (i.e. it became less negative) by 0.9 mV (p>0.1); changing from warmed to room temperature increased NPD by 2.1 mV (p<0.05). During isoprenaline perfusion, changing from room temperature to warmed solutions increased NPD by 1.5 mV (p<0.01) and from warmed to room temperature decreased NPD by 1.4 mV (p<0.05). For full protocols at room temperature or warmed in the same subjects, mean values were similar (n = 24). During warmed perfusion, group results for total chloride response had a larger standard deviation. As this increased variability will probably decrease the power of trials, this study suggests that solutions at room temperature should be recommended for the measurement of NPD. PMID:23100510

  9. Potential climatic impacts and reliability of very large-scale wind farms

    NASA Astrophysics Data System (ADS)

    Wang, C.; Prinn, R. G.

    2009-09-01

    Meeting future world energy needs while addressing climate change requires large-scale deployment of low or zero greenhouse gas (GHG) emission technologies such as wind energy. The widespread availability of wind power has fueled legitimate interest in this renewable energy source as one of the needed technologies. For very large-scale utilization of this resource, there are however potential environmental impacts, and also problems arising from its inherent intermittency, in addition to the present need to lower unit costs. To explore some of these issues, we use a three-dimensional climate model to simulate the potential climate effects associated with installation of wind-powered generators over vast areas of land or coastal ocean. Using wind turbines to meet 10% or more of global energy demand in 2100, could cause surface warming exceeding 1C over land installations. In contrast, surface cooling exceeding 1C is computed over ocean installations, but the validity of simulating the impacts of wind turbines by simply increasing the ocean surface drag needs further study. Significant warming or cooling remote from both the land and ocean installations, and alterations of the global distributions of rainfall and clouds also occur. These results are influenced by the competing effects of increases in roughness and decreases in wind speed on near-surface turbulent heat fluxes, the differing nature of land and ocean surface friction, and the dimensions of the installations parallel and perpendicular to the prevailing winds. These results are also dependent on the accuracy of the model used, and the realism of the methods applied to simulate wind turbines. Additional theory and new field observations will be required for their ultimate validation. Intermittency of wind power on daily, monthly and longer time scales as computed in these simulations and inferred from meteorological observations, poses a demand for one or more options to ensure reliability, including backup generation capacity, very long distance power transmission lines, and onsite energy storage, each with specific economic and/or technological challenges.

  10. Potential climatic impacts and reliability of very large-scale wind farms

    NASA Astrophysics Data System (ADS)

    Wang, C.; Prinn, R. G.

    2010-02-01

    Meeting future world energy needs while addressing climate change requires large-scale deployment of low or zero greenhouse gas (GHG) emission technologies such as wind energy. The widespread availability of wind power has fueled substantial interest in this renewable energy source as one of the needed technologies. For very large-scale utilization of this resource, there are however potential environmental impacts, and also problems arising from its inherent intermittency, in addition to the present need to lower unit costs. To explore some of these issues, we use a three-dimensional climate model to simulate the potential climate effects associated with installation of wind-powered generators over vast areas of land or coastal ocean. Using wind turbines to meet 10% or more of global energy demand in 2100, could cause surface warming exceeding 1 C over land installations. In contrast, surface cooling exceeding 1 C is computed over ocean installations, but the validity of simulating the impacts of wind turbines by simply increasing the ocean surface drag needs further study. Significant warming or cooling remote from both the land and ocean installations, and alterations of the global distributions of rainfall and clouds also occur. These results are influenced by the competing effects of increases in roughness and decreases in wind speed on near-surface turbulent heat fluxes, the differing nature of land and ocean surface friction, and the dimensions of the installations parallel and perpendicular to the prevailing winds. These results are also dependent on the accuracy of the model used, and the realism of the methods applied to simulate wind turbines. Additional theory and new field observations will be required for their ultimate validation. Intermittency of wind power on daily, monthly and longer time scales as computed in these simulations and inferred from meteorological observations, poses a demand for one or more options to ensure reliability, including backup generation capacity, very long distance power transmission lines, and onsite energy storage, each with specific economic and/or technological challenges.

  11. Modelling potential changes in marine biogeochemistry due to large-scale offshore wind farms

    NASA Astrophysics Data System (ADS)

    van der Molen, Johan; Rees, Jon; Limpenny, Sian

    2013-04-01

    Large-scale renewable energy generation by offshore wind farms may lead to changes in marine ecosystem processes through the following mechanism: 1) wind-energy extraction leads to a reduction in local surface wind speeds; 2) these lead to a reduction in the local wind wave height; 3) as a consequence there's a reduction in SPM resuspension and concentrations; 4) this results in an improvement in under-water light regime, which 5) may lead to increased primary production, which subsequently 6) cascades through the ecosystem. A three-dimensional coupled hydrodynamics-biogeochemistry model (GETM_ERSEM) was used to investigate this process for a hypothetical wind farm in the central North Sea, by running a reference scenario and a scenario with a 10% reduction (as was found in a case study of a small farm in Danish waters) in surface wind velocities in the area of the wind farm. The ERSEM model included both pelagic and benthic processes. The results showed that, within the farm area, the physical mechanisms were as expected, but with variations in the magnitude of the response depending on the ecosystem variable or exchange rate between two ecosystem variables (3-28%, depending on variable/rate). Benthic variables tended to be more sensitive to the changes than pelagic variables. Reduced, but noticeable changes also occurred for some variables in a region of up to two farm diameters surrounding the wind farm. An additional model run in which the 10% reduction in surface wind speed was applied only for wind speeds below the generally used threshold of 25 m/s for operational shut-down showed only minor differences from the run in which all wind speeds were reduced. These first results indicate that there is potential for measurable effects of large-scale offshore wind farms on the marine ecosystem, mainly within the farm but for some variables up to two farm diameters away. However, the wave and SPM parameterisations currently used in the model are crude and need to be further tested and refined. Also, potential counter-acting processes such as possible increases in SPM concentrations due to turbulence generated by the wind-turbine foundations may need to be included for more accurate simulations. Moreover, it is unclear to what extent these results would be valid for areas where different hydrodynamic characteristics may predominate, e.g. with summer stratification or strong tidal currents. Finally, an assessment would need to be carried out of how beneficial or detrimental these potential changes might be from various social-economic and ecosystem-management points of view.

  12. Artificial Boundary Conditions Based on the Difference Potentials Method

    NASA Technical Reports Server (NTRS)

    Tsynkov, Semyon V.

    1996-01-01

    While numerically solving a problem initially formulated on an unbounded domain, one typically truncates this domain, which necessitates setting the artificial boundary conditions (ABC's) at the newly formed external boundary. The issue of setting the ABC's appears to be most significant in many areas of scientific computing, for example, in problems originating from acoustics, electrodynamics, solid mechanics, and fluid dynamics. In particular, in computational fluid dynamics (where external problems present a wide class of practically important formulations) the proper treatment of external boundaries may have a profound impact on the overall quality and performance of numerical algorithms. Most of the currently used techniques for setting the ABC's can basically be classified into two groups. The methods from the first group (global ABC's) usually provide high accuracy and robustness of the numerical procedure but often appear to be fairly cumbersome and (computationally) expensive. The methods from the second group (local ABC's) are, as a rule, algorithmically simple, numerically cheap, and geometrically universal; however, they usually lack accuracy of computations. In this paper we first present a survey and provide a comparative assessment of different existing methods for constructing the ABC's. Then, we describe a relatively new ABC's technique of ours and review the corresponding results. This new technique, in our opinion, is currently one of the most promising in the field. It enables one to construct such ABC's that combine the advantages relevant to the two aforementioned classes of existing methods. Our approach is based on application of the difference potentials method attributable to V. S. Ryaben'kii. This approach allows us to obtain highly accurate ABC's in the form of certain (nonlocal) boundary operator equations. The operators involved are analogous to the pseudodifferential boundary projections first introduced by A. P. Calderon and then also studied by R. T. Seeley. The apparatus of the boundary pseudodifferential equations, which has formerly been used mostly in the qualitative theory of integral equations and PDE'S, is now effectively employed for developing numerical methods in the different fields of scientific computing.

  13. Reduction of the field-aligned potential drop in the polar cap during large geomagnetic storms

    NASA Astrophysics Data System (ADS)

    Kitamura, N.; Seki, K.; Nishimura, Y.; Hori, T.; Terada, N.; Ono, T.; Strangeway, R. J.

    2013-12-01

    We have studied photoelectron flows and the inferred field-aligned potential drop in the polar cap during 5 large geomagnetic storms that occurred in the periods when the photoelectron observations in the polar cap were available near the apogee of the FAST satellite (~4000 km) at solar maximum, and the footprint of the satellite paths in the polar cap was under sunlit conditions most of the time. In contrast to the ~20 V potential drop during geomagnetically quiet periods at solar maximum identified by Kitamura et al. [JGR, 2012], the field-aligned potential drop frequently became smaller than ~5 V during the main and early recovery phases of the large geomagnetic storms. Because the potential acts to inhibit photoelectron escape, this result indicates that the corresponding acceleration of ions by the field-aligned potential drop in the polar cap and the lobe region is smaller during the main and early recovery phases of large geomagnetic storms compared to during geomagnetically quiet periods. Under small field-aligned current conditions, the number flux of outflowing ions should be nearly equal to the net escaping electron number flux. Since ions with large flux originating from the cusp/cleft ionosphere convect into the polar cap during geomagnetic storms [e.g., Kitamura et al., JGR, 2010], the net escaping electron number flux should increase to balance the enhanced ion outflows. The magnitude of the field-aligned potential drop would be reduced to let a larger fraction of photoelectrons escape.

  14. Small differences in amylopectin fine structure may explain large functional differences of starch.

    PubMed

    Bertoft, Eric; Annor, George A; Shen, Xinyu; Rumpagaporn, Pinthip; Seetharaman, Koushik; Hamaker, Bruce R

    2016-04-20

    Four amylose-free waxy rice starches were found to give rise to gels with clearly different morphology after storage for seven days at 4°C. The thermal and rheological properties of these gels were also different. This was remarkable in light of the subtle differences in the molecular structure of the amylopectin in the samples. Addition of iodine to the amylopectin samples suggested that not only external chains, but also the internal chains of amylopectin, could form helical inclusion complexes. It is suggested that these internal helical segments participate in the retrogradation of amylopectin, thereby stabilising the gels through double helical structures with external chains of adjacent molecules. Albeit few in number, such interactions appear to have important influences on starch functional properties. PMID:26876834

  15. Assessment of economically optimal water management and geospatial potential for large-scale water storage

    NASA Astrophysics Data System (ADS)

    Weerasinghe, Harshi; Schneider, Uwe A.

    2010-05-01

    Assessment of economically optimal water management and geospatial potential for large-scale water storage Weerasinghe, Harshi; Schneider, Uwe A Water is an essential but limited and vulnerable resource for all socio-economic development and for maintaining healthy ecosystems. Water scarcity accelerated due to population expansion, improved living standards, and rapid growth in economic activities, has profound environmental and social implications. These include severe environmental degradation, declining groundwater levels, and increasing problems of water conflicts. Water scarcity is predicted to be one of the key factors limiting development in the 21st century. Climate scientists have projected spatial and temporal changes in precipitation and changes in the probability of intense floods and droughts in the future. As scarcity of accessible and usable water increases, demand for efficient water management and adaptation strategies increases as well. Addressing water scarcity requires an intersectoral and multidisciplinary approach in managing water resources. This would in return safeguard the social welfare and the economical benefit to be at their optimal balance without compromising the sustainability of ecosystems. This paper presents a geographically explicit method to assess the potential for water storage with reservoirs and a dynamic model that identifies the dimensions and material requirements under an economically optimal water management plan. The methodology is applied to the Elbe and Nile river basins. Input data for geospatial analysis at watershed level are taken from global data repositories and include data on elevation, rainfall, soil texture, soil depth, drainage, land use and land cover; which are then downscaled to 1km spatial resolution. Runoff potential for different combinations of land use and hydraulic soil groups and for mean annual precipitation levels are derived by the SCS-CN method. Using the overlay and decision tree algorithms in GIS, potential water storage sites are identified for constructing regional reservoirs. Subsequently, sites are prioritized based on runoff generation potential (m3 per unit area), and geographical suitability for constructing storage structures. The results from the spatial analysis are used as input for the optimization model. Allocation of resources and appropriate dimension for dams and associated structures are identified using the optimization model. The model evaluates the capability of alternative reservoirs for cost-efficient water management. The Geographic Information System is used to store, analyze, and integrate spatially explicit and non-spatial attribute information whereas the algebraic modeling platform is used to develop the dynamic optimization model. The results of this methodology are validated over space against satellite remote sensing data and existing data on reservoir capacities and runoff. The method is suitable for application of on-farm water storage structures, water distribution networks, and moisture conservation structures in a global context.

  16. Electrodiffusiophoresis of a large-zeta-potential particle in weak fields

    NASA Astrophysics Data System (ADS)

    Tricoli, Vincenzo; Orsini, Gabriele

    2015-10-01

    The electrodiffusiophoresis of a large-zeta-potential (ζ) particle in weak fields is investigated. In this large-ζ regime, Debye-layer kinetics determines O(1) perturbations to the electric- and concentration fields in the surrounding electroneutral solution. Taking these effects into account, the expressions of the slip-flow coefficient and the effective surface boundary-conditions for the electric- and concentration fields are derived. For binary and symmetric electrolyte where only one ion species carries the current in the electroneutral domain, the far-field salt gradient as related to the electric field is determined. The electrodiffusiophoretic mobility is obtained for three particle geometries: sphere, cylinder and spheroid arbitrarily oriented with respect to the externally applied field. Strong departure from Smoluchowskian behavior is found. If co-ion is the current carrier, the mobility is independent of ζ, regardless of the body shape. Also, the hydrodynamic flow-field is irrotational. If counter-ion is the current carrier, the problem formulated in terms of a properly-defined scalar field (Ω), which embodies both the electric potential (Ψ) and the salt concentration, becomes formally identical to the one addressed in our previous work, concerning the small-ζ regime, with negligible salt gradients. Then, all the results obtained in that study are extended and applied even to the large-ζ regime considered here, provided the new expressions now derived for the surface boundary conditions and the slip-flow coefficient are employed and Ω is used in place of Ψ. The present results are discussed also in comparison with the classical studies of Dukhin et al and O’Brien et al concerning electrophoresis of highly charged particles with no salt gradient at infinity, and with recent studies of electrodiffusiophoresis, which, however, neglected the fields perturbations caused by Debye-layer kinetics. It is found that the effects addressed and incorporated in the present study determine remarkably different mobility-versus-ζ behaviour as compared to those previous theories.

  17. Electroviscous effect on fluid drag in a microchannel with large zeta potential

    PubMed Central

    Jing, Dalei

    2015-01-01

    Summary The electroviscous effect has been widely studied to investigate the effect of surface charge-induced electric double layers (EDL) on the pressure-driven flow in a micro/nano channel. EDL has been reported to reduce the velocity of fluid flow and increase the fluid drag. Nevertheless, the study on the combined effect of EDL with large zeta potential up to several hundred millivolts and surface charge depenedent-slip on the micro/nano flow is still needed. In this paper, the nonlinear Poisson–Boltzmann equation for electrical potential and ion distribution in non-overlapping EDL is first analytically solved. Then, the modified Navier–Stokes equation for the flow considering the effect of surface charge on the electrical conductivity of the electrolyte and slip length is analytically solved. This analysis is used to study the effect of non-overlapping EDL with large zeta potential on the pressure-driven flow in a microchannel with no-slip and charge-dependent slip conditions. The results show that the EDL leads to an increase in the fluid drag, but that slip can reduce the fluid drag. When the zeta potential is large enough, the electroviscous effect disappears for flow in the microchannel under a no-slip condition. However, the retardation of EDL on the flow and the enhancement of slip on the flow counteract each other under a slip condition. The underlying mechanisms of the effect of EDL with large zeta potential on fluid drag are the high net ionic concentration near the channel wall and the fast decay of electrical potential in the EDL when the zeta potential is large enough. PMID:26734512

  18. Large Autosomal Copy-Number Differences within Unselected Monozygotic Twin Pairs are Rare.

    PubMed

    McRae, Allan F; Visscher, Peter M; Montgomery, Grant W; Martin, Nicholas G

    2015-02-01

    Monozygotic (MZ) twins form an important system for the study of biological plasticity in humans. While MZ twins are generally considered to be genetically identical, a number of studies have emerged that have demonstrated copy-number differences within a twin pair, particularly in those discordant for disease. The rate of autosomal copy-number variation (CNV) discordance within MZ twin pairs was investigated using a population sample of 376 twin pairs genotyped on Illumina Human610-Quad arrays. After CNV calling using both QuantiSNP and PennCNV followed by manual annotation, only a single CNV difference was observed within the MZ twin pairs, being a 130 KB duplication of chromosome 5. Five other potential discordant CNV were called by the software, but excluded based on manual annotation of the regions. It is concluded that large CNV discordance is rare within MZ twin pairs, indicating that any CNV difference found within phenotypically discordant MZ twin pairs has a high probability of containing the causal gene(s) involved. PMID:25578400

  19. Assessment of Sugarcane Yield Potential across Large Numbers of Genotypes Using Canopy Reflectance Measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canopy reflectance indices have been used to monitor plant growth and estimate yields in many field crops. Little is known if canopy reflectance of sugarcane (a complex hybrid of Saccharum spp.) can be used to estimate growth and yield potential across large numbers of genotypes (clones) in the earl...

  20. PERSPECTIVES ON LARGE-SCALE NATURAL RESOURCES SURVEYS WHEN CAUSE-EFFECT IS A POTENTIAL ISSUE

    EPA Science Inventory

    Our objective is to present a perspective on large-scale natural resource monitoring when cause-effect is a potential issue. We believe that the approach of designing a survey to meet traditional commodity production and resource state descriptive objectives is too restrictive an...

  1. Bose–Einstein condensation in large time-averaged optical ring potentials

    NASA Astrophysics Data System (ADS)

    Bell, Thomas A.; Glidden, Jake A. P.; Humbert, Leif; Bromley, Michael W. J.; Haine, Simon A.; Davis, Matthew J.; Neely, Tyler W.; Baker, Mark A.; Rubinsztein-Dunlop, Halina

    2016-03-01

    Interferometric measurements with matter waves are established techniques for sensitive gravimetry, rotation sensing, and measurement of surface interactions, but compact interferometers will require techniques based on trapped geometries. In a step towards the realisation of matter wave interferometers in toroidal geometries, we produce a large, smooth ring trap for Bose–Einstein condensates using rapidly scanned time-averaged dipole potentials. The trap potential is smoothed by using the atom distribution as input to an optical intensity correction algorithm. Smooth rings with a diameter up to 300 μm are demonstrated. We experimentally observe and simulate the dispersion of condensed atoms in the resulting potential, with good agreement serving as an indication of trap smoothness. Under time of flight expansion we observe low energy excitations in the ring, which serves to constrain the lower frequency limit of the scanned potential technique. The resulting ring potential will have applications as a waveguide for atom interferometry and studies of superfluidity.

  2. Serber symmetry, large N{sub c}, and Yukawa-like one-boson exchange potentials

    SciTech Connect

    Calle Cordon, A.; Arriola, E. Ruiz

    2009-07-15

    The Serber force has relative orbital parity symmetry and requires vanishing NN interactions in partial waves with odd angular momentum. We illustrate how this property is well fulfilled for spin triplet states with odd angular momentum and violated for odd singlet states for realistic potentials but fails for chiral potentials. The analysis is carried out in terms of partial wave sum rules for NN phase shifts, r-space potentials at long distances, and V{sub lowk} potentials. We analyze how Serber symmetry can be accommodated within a large-N{sub c} perspective when interpreted as a long-distance symmetry. A prerequisite for this is the numerical similarity of the scalar and vector meson resonance masses. The conditions under which the resonance exchange potential can be approximated by a Yukawa form are also discussed. Although these masses arise as poles on the second Riemann in {pi}{pi} scattering, we find that within the large-N{sub c} expansion the corresponding Yukawa masses correspond instead to a well-defined large-N{sub c} approximation to the pole that cannot be distinguished from their location as Breit-Wigner resonances.

  3. Floating potential of large dust grains in a collisionless flowing plasma.

    PubMed

    Willis, C T N; Coppins, M; Bacharis, M; Allen, J E

    2012-03-01

    Dust immersed in plasma quickly charges to a potential where the ion and electron currents to its surface balance; this is the floating potential. In order to accurately determine dust behavior, the floating potential must be known. The charging of dust grains that are small with respect to electron Debye length (?(D)) may be adequately approximated using the orbital-motion-limited (OML) approach. A modified version of OML is presented for large dust grains in both stationary and flowing plasmas. This modified OML is compared with simulation and found to be in good agreement. The modified OML is applied to large grains charging under tokamak conditions and found to have an appreciable effect on the drag force. PMID:22587192

  4. Modelling potential changes in marine biogeochemistry due to large-scale offshore tidal energy extraction

    NASA Astrophysics Data System (ADS)

    van der Molen, Johan

    2015-04-01

    Tidal power generation through submerged turbine-type devices is in an advanced stage of testing, and large-scale applications are being planned in areas with high tidal current speeds. The potential impact of such large-scale applications on the hydrography can be investigated using hydrodynamical models. In addition, aspects of the potential impact on the marine ecosystem can be studied using biogeochemical models. In this study, the coupled hydrodynamics-biogeochemistry model GETM-ERSEM is used in a shelf-wide application to investigate the potential impact of large-scale tidal power generation in the Pentland Firth. A scenario representing the currently licensed power extraction suggested i) an average reduction in M2 tidal current velocities of several cm/s within the Pentland Firth, ii) changes in the residual circulation of several mm/s in the vicinity of the Pentland Firth, iii) an increase in M2 tidal amplitude of up to 1 cm to the west of the Pentland Firth, and iv) a reduction of several mm in M2 tidal amplitude along the east coast of the UK. A second scenario representing 10 times the currently licensed power extraction resulted in changes that were approximately 10 times as large. Simulations including the biogeochemistry model for these scenarios are currently in preparation, and first results will be presented at the the conference, aiming at impacts on primary production and benthic production.

  5. Evaluating Potential for Large Releases from CO2 StorageReservoirs: Analogs, Scenarios, and Modeling Needs

    SciTech Connect

    Birkholzer, Jens; Pruess, Karsten; Lewicki, Jennifer; Tsang,Chin-Fu; Karimjee, Anhar

    2005-09-19

    While the purpose of geologic storage of CO{sub 2} in deep saline formations is to trap greenhouse gases underground, the potential exists for CO{sub 2} to escape from the target reservoir, migrate upward along permeable pathways, and discharge at the land surface. Such discharge is not necessarily a serious concern, as CO{sub 2} is a naturally abundant and relatively benign gas in low concentrations. However, there is a potential risk to health, safety and environment (HSE) in the event that large localized fluxes of CO{sub 2} were to occur at the land surface, especially where CO{sub 2} could accumulate. In this paper, we develop possible scenarios for large CO{sub 2} fluxes based on the analysis of natural analogues, where large releases of gas have been observed. We are particularly interested in scenarios which could generate sudden, possibly self-enhancing, or even eruptive release events. The probability for such events may be low, but the circumstances under which they might occur and potential consequences need to be evaluated in order to design appropriate site selection and risk management strategies. Numerical modeling of hypothetical test cases is needed to determine critical conditions for such events, to evaluate whether such conditions may be possible at designated storage sites, and, if applicable, to evaluate the potential HSE impacts of such events and design appropriate mitigation strategies.

  6. Altered ion channel conductance and ionic selectivity induced by large imposed membrane potential pulse.

    PubMed Central

    Chen, W; Lee, R C

    1994-01-01

    The effects of large magnitude transmembrane potential pulses on voltage-gated Na and K channel behavior in frog skeletal muscle membrane were studied using a modified double vaseline-gap voltage clamp. The effects of electroconformational damage to ionic channels were separated from damage to lipid bilayer (electroporation). A 4 ms transmembrane potential pulse of -600 mV resulted in a reduction of both Na and K channel conductivities. The supraphysiologic pulses also reduced ionic selectivity of the K channels against Na+ ions, resulting in a depolarization of the membrane resting potential. However, TTX and TEA binding effects were unaltered. The kinetics of spontaneous reversal of the electroconformational damage of channel proteins was found to be dependent on the magnitude of imposed membrane potential pulse. These results suggest that muscle and nerve dysfunction after electrical shock may be in part caused by electroconformational damage to voltage-gated ion channels. PMID:7948676

  7. Assessment of groundwater potential for conjunctive water use in a large irrigation project in India

    NASA Astrophysics Data System (ADS)

    Sondhi, S. K.; Rao, N. H.; Sarma, P. B. S.

    1989-05-01

    In many large-surface irrigation projects, the potential for groundwater development has increased significantly. The additional potential can be used to develop conjunctive water management plans for augmenting canal water supplies and increasing agricultural productivity in the project area, if its spatial distribution is also known. A methodology for determining the available additional groundwater potential and its distribution in the Mahi Right Bank Canal Project in Gujarat is presented. The procedure is based on the use of specific empirical constants for estimating groundwater recharge from the water conveyance and distribution system and the annual water balance of the project. The spatial distribution of groundwater potential is determined by "recharge distribution coefficients" derived from a digital simulation model of the groundwater basin of the project area.

  8. Potential use of a large-screen display for interpreting radiographic images

    NASA Astrophysics Data System (ADS)

    Krupinski, Elizabeth; Roehrig, Hans; Berger, William; Dalal, Sandeep; Stanton, Douglas

    2006-03-01

    Radiology has readily made the transition to the digital reading room. One commodity left behind when moving to digital displays however is display real estate. Even with multiple monitors radiologists cannot display numerous images as they did on a film alternator. We evaluated a large-screen rear-projection display (Philips Electronics) for potential use in radiology. Resolution was 1920 x 1080 with a 44-inch diagonal size and it was a color display. For comparison we used the IBM 9 Mpixel color display (22-inch diagonal) set to a comparable resolution and maximum luminance. Diagnostic accuracy with a series of bone images with subtle fractures and six observers was comparable (F = 0.3170, p = 0.5743) to traditional computer monitor. Viewing time, however, was significantly shorter (t = 6.723, p < 0.0001) with the large display for both normal and fracture images. On average, readers sat significantly closer (t = 5.578, p = 0.0026) to the small display than the large display. Four of the 6 radiologists preferred the smaller display, judging it to yield a sharper image. Half of the readers thought the black level was better with the large display and half with the small display. Most of the radiologists thought the large-screen display has potential for use in conferencing situations or those in which multiple viewers need to see images simultaneously.

  9. Immobilization of potentially toxic metals using different soil amendments.

    PubMed

    Tica, D; Udovic, M; Lestan, D

    2011-10-01

    The in situ stabilization of potentially toxic metals (PTMs), using various easily available amendments, is a cost-effective remediation method for contaminated soils. In the present study, we investigated the effectiveness of apatite and a commercial mixture of dolomite, diatomite, smectite basaltic tuff, bentonite, alginite and zeolite (Slovakite) on Pb, Zn, Cu and Cd stabilization by means of decreasing their bioavailability in contaminated soil from an old lead and zinc smelter site in Arnoldstein, Austria. We also investigated the impact of 5% (w/w) apatite and Slovakite applications on soil functionality and quality, as assessed by glucose-induced soil respiration, dehydrogenase, acid and alkaline phosphatase and β-glucosidase activity. Both amendments resulted in increased soil pH and decreased PTM potential bioavailability assessed by diethylenetriamine pentaacetic acid extraction and by sequential extractions in the water-soluble and exchangeable fractions. The efficiency of stabilization was reflected in the soil respiration rate and in enzymatic activity. The β-glucosidase activity assay was the most responsive of them. PMID:21767865

  10. Torus Construction in Potentials Supporting Different Orbit Families

    NASA Astrophysics Data System (ADS)

    Kaasalainen, M.

    1994-06-01

    The methods of McGill & Binney and Kaasalainen & Binney are employed in creating invariant phase-space tori in non-integrable potentials supporting minor-orbit families. Following Binney & Kumar, these tori are used to define an integrable Hamiltonian H0closely approximating the original one, and Hamiltonian perturbation theory is then used to demonstrate that a minor-orbit family can be treated as one made up of orbits trapped by a resonance of H0. The main objectives of this paper are (i) to develop a model for perturbative calculations, resembling the pendulum analysis of standard secular perturbation theory, that takes into account the special properties of H0, and (ii) to show how H0 may be constructed in the presence of powerful resonances, which render ineffective the approach of Binney & Kumar. As an illustration of the method, the `banana' and `fish' minor-orbit families in the planar logarithmic potential are explicitly derived by perturbing constructed H0s.

  11. Characterization and potential functional significance of human-chimpanzee large INDEL variation

    PubMed Central

    2011-01-01

    Background Although humans and chimpanzees have accumulated significant differences in a number of phenotypic traits since diverging from a common ancestor about six million years ago, their genomes are more than 98.5% identical at protein-coding loci. This modest degree of nucleotide divergence is not sufficient to explain the extensive phenotypic differences between the two species. It has been hypothesized that the genetic basis of the phenotypic differences lies at the level of gene regulation and is associated with the extensive insertion and deletion (INDEL) variation between the two species. To test the hypothesis that large INDELs (80 to 12,000 bp) may have contributed significantly to differences in gene regulation between the two species, we categorized human-chimpanzee INDEL variation mapping in or around genes and determined whether this variation is significantly correlated with previously determined differences in gene expression. Results Extensive, large INDEL variation exists between the human and chimpanzee genomes. This variation is primarily attributable to retrotransposon insertions within the human lineage. There is a significant correlation between differences in gene expression and large human-chimpanzee INDEL variation mapping in genes or in proximity to them. Conclusions The results presented herein are consistent with the hypothesis that large INDELs, particularly those associated with retrotransposons, have played a significant role in human-chimpanzee regulatory evolution. PMID:22024410

  12. Atrial flutter with a large bystander segment without double potentials in the cavotricuspid isthmus.

    PubMed

    Adachi, Masamitsu; Igawa, Osamu; Yano, Akio; Inoue, Yoshiaki

    2007-10-01

    We present two cases of common-type atrial flutter with a large bystander segment without double potentials in the cavotricuspid isthmus. In both cases, right atrial angiography demonstrated a prominent pouch at the center of the isthmus. When radiofrequency energy was applied to the tricuspid side of the isthmus, delayed potentials abruptly appeared on the local electrograms. When radiofrequency energy was applied on the inferior vena cava side of the isthmus, the tachycardia was terminated. Although ablation was not applied to the bottom of the pouch, bidirectional isthmus block was achieved. These outcomes indicate that the pouch represented a bystander segment. PMID:17905342

  13. Large endolymphatic potentials from low-frequency and infrasonic tones in the guinea pig.

    PubMed

    Salt, Alec N; Lichtenhan, Jeffery T; Gill, Ruth M; Hartsock, Jared J

    2013-03-01

    Responses of the ear to low-frequency and infrasonic sounds have not been extensively studied. Understanding how the ear responds to low frequencies is increasingly important as environmental infrasounds are becoming more pervasive from sources such as wind turbines. This study shows endolymphatic potentials in the third cochlear turn from acoustic infrasound (5?Hz) are larger than from tones in the audible range (e.g., 50 and 500?Hz), in some cases with peak-to-peak amplitude greater than 20?mV. These large potentials were suppressed by higher-frequency tones and were rapidly abolished by perilymphatic injection of KCl at the cochlear apex, demonstrating their third-turn origins. Endolymphatic iso-potentials from 5 to 500?Hz were enhanced relative to perilymphatic potentials as frequency was lowered. Probe and infrasonic bias tones were used to study the origin of the enhanced potentials. Potentials were best explained as a saturating response summed with a sinusoidal voltage (Vo), that was phase delayed by an average of 60 relative to the biasing effects of the infrasound. Vo is thought to arise indirectly from hair cell activity, such as from strial potential changes caused by sustained current changes through the hair cells in each half cycle of the infrasound. PMID:23464026

  14. Large herbivores maintain termite-caused differences in herbaceous species diversity patterns.

    PubMed

    Okullo, Paul; Moe, Stein R

    2012-09-01

    Termites and large herbivores affect African savanna plant communities. Both functional groups are also important for nutrient redistribution across the landscape. We conducted an experiment to study how termites and large herbivores, alone and in combination, affect herbaceous species diversity patterns in an African savanna. Herbaceous vegetation on large vegetated Macrotermes mounds (with and without large herbivores) and on adjacent savanna areas (with and without large herbivores) was monitored over three years in Lake Mburo National Park, Uganda. We found substantial differences in species richness, alpha diversity, evenness, and stability between termite mound herbaceous vegetation and adjacent savanna vegetation. Within months of fencing, levels of species richness, evenness, and stability were no longer significantly different between savanna and mounds. However, fencing reduced the cumulative number of species, particularly for forbs, of which 48% of the species were lost. Fencing increased the beta diversity (dissimilarity among plots) on the resource-poor (in terms of both nutrients and soil moisture) savanna areas, while it did not significantly affect beta diversity on the resource-rich termite mounds. While termites cause substantial heterogeneity in savanna vegetation, large herbivores further amplify these differences by reducing beta diversity on the savanna areas. Large herbivores are, however, responsible for the maintenance of a large number of forbs at the landscape level. These findings suggest that the mechanisms underlying the effects of termites and large herbivores on savanna plant communities scale up to shape community structure and dynamics at a landscape level. PMID:23094381

  15. Sagdeev potential approach for large amplitude compressional Alfvenic double layers in viscous plasmas

    SciTech Connect

    Panwar, Anuraj; Rizvi, H.; Ryu, C. M.

    2013-11-15

    Sagdeevs technique is used to study the large amplitude compressional Alfvenic double layers in a magnetohydrodynamic plasma taking into account the small plasma ? and small values of kinematic viscosity. Dispersive effect raised by non-ideal electron inertia currents perpendicular to the ambient magnetic field. The range of allowed values of the soliton speed, M (Mach number), plasma ? (ratio of the plasma thermal pressure to the pressure in the confining magnetic field), and viscosity coefficient, wherein double layer may exist, are determined. In the absence of collisions, viscous dissipation modifies the Sagdeev potential and results in large amplitude compressional Alfvenic double layers. The depth of Sagdeev potential increases with the increasing Mach number and plasma ?, however, decreases with the increasing viscosity. The double layer structure increases with the increasing plasma ?, but decreases with increasing viscous dissipation ?(tilde sign)

  16. Large 0/12 GMT Differences of US Vaisala RS80 Observations

    NASA Technical Reports Server (NTRS)

    Atlas, Robert (Technical Monitor)

    2002-01-01

    Large differences been observations taken at 0 and 12 GMT have been revealed during routine monitoring of observations at the Data Assimilation Office (DAO) at NASA's Goddard Space Flight Center (GSFC). As a result, an investigation has been conducted to confirm the large differences and isolate its source. The data clearly shows that 0/12 GMT differences are largely artificial especially over the central US and that the differences largely originate in the post processing software at the observing stations. In particular, the release time of the rawinsonde balloon may be misspecified to be the synoptic time which would lead to the miscalculation of the bias correction that accounts for solar radiation effects on the thermistor.

  17. Assessment of the probability of extreme weather events and their potential effects in large conurbations

    NASA Astrophysics Data System (ADS)

    Wagner, Dieter

    The likelihood of occurrence of extreme high-temperature run events is estimated for different values of the event intensity and persistence from very long synthetic time series of daily maximum temperatures generated by Monte Carlo simulations using a first-order autoregressive or Markov model. A theoretical analysis reveals a higher relative sensitivity of the simulated extreme event probabilities to changes in the variability of climate than to changes in its mean state. Moreover, this sensitivity relatively increases at a nonlinear rate the more extreme the event. The developed probabilistic model is applied in order to derive local scenarios of extreme high-temperature run events for a large conurbation like the city of Berlin assuming both arbitrary hypothetical and physically based new climate states described by changes in the model parameters (e.g. the mean, the standard deviation and the first-order autocorrelation of the daily maximum temperature time series). As a consequence of a 1.7C increase in the mean as well as a 19% increase in the temperature variability in July as predicted by the climate model ECHAM_1/LSG assuming an unrestricted future increase in the global atmospheric concentration of climate relevant greenhouse gases according to the IPCC Scenario A ("Business as usual") the intensity as well as the persistence of extreme high-temperature run events will rise considerably up to the end of the next century. In particular, intense hot spells characterized by at least five consecutive daily maximum temperatures equaling or exceeding 33C are expected to occur every eight years under the new climate conditions compared to a current repetition time of about 47 years. The potential environmental effects might be a significant increase in the heat-stress-related morbidity and mortality rate, an aggravation of the summer smog situation and a destabilization of the urban ecosystems.

  18. On hemispheric differences in evoked potentials to speech stimuli

    NASA Technical Reports Server (NTRS)

    Galambos, R.; Smith, T. S.; Schulman-Galambos, C.; Osier, H.; Benson, P.

    1975-01-01

    Subjects were asked to count the number of times a 'target' sound occurred in lists of speech sounds (pa or ba) or pure tones (250 or 600 c/sec) in which one of the sounds (the 'frequent') appeared about four times as often as the target. The response to both targets and frequents were separately averaged from electrodes at vertex at symmetrical left and right parietal locations. The expected sequence of deflections, including P3 waves with about 350 msec latency, was found in the responses to target stimuli. Very little difference was found between the right and left hemispheric responses to speech or pure tones, either frequent or target.

  19. The potential for agricultural land use change to reduce flood risk in a large watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of agricultural land management practices on surface runoff are evident at local scales, but evidence for watershed-scale impacts is limited. In this study, we used the Soil and Water Assessment Tool model to assess changes in downstream flood risks under different land uses for the large, ...

  20. 77 FR 11111 - Assessment of Potential Large-Scale Mining on the Bristol Bay Watershed of Alaska: Nomination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... AGENCY Assessment of Potential Large-Scale Mining on the Bristol Bay Watershed of Alaska: Nomination of... impacts associated with potential large-scale mining development in the Nushagak and Kvichak watersheds of... how large-scale mining activities might affect water quality and habitat. EPA will focus primarily...

  1. 77 FR 14011 - Assessment of Potential Large-Scale Mining on the Bristol Bay Watershed of Alaska: Nomination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-08

    ... AGENCY Assessment of Potential Large-Scale Mining on the Bristol Bay Watershed of Alaska: Nomination of... associated with potential large-scale mining development in the Nushagak and Kvichak watersheds of Bristol... understand how large-scale mining activities might affect water quality and habitat. EPA will focus...

  2. Quantitative potential measurements of nanoparticles with different surface charges in liquid by open-loop electric potential microscopy

    NASA Astrophysics Data System (ADS)

    Kobayashi, Naritaka; Asakawa, Hitoshi; Fukuma, Takeshi

    2011-08-01

    Local potential distribution plays important roles in physical, chemical and biological processes at a solid/liquid interface. However, the measurement of a local potential distribution in liquid has been a long-standing challenge, which has hindered understanding of the mechanisms for the various interfacial phenomena. Recently, we have developed a method to overcome this problem [Kobayashi et al., Rev. Sci. Instrum. 81, 123705 (2010)], which is referred to as open-loop electric potential microscopy (OL-EPM). Here, we present its first application to quantitative measurements of local potential distribution in liquid. In OL-EPM, an ac bias voltage is applied between a tip and sample and the first and second harmonic cantilever oscillations induced by the electrostatic force are detected and used for the calculation of a potential value. In the equation for the potential calculation, here we introduce a correction factor to cancel out the error caused by the difference in the deflection sensitivity to the first and second harmonic electrostatic forces. With the improved method, we have performed potential measurements of two types of latex beads with different surface charges. The measured potential difference between the different types of latex beads approximately corresponds to their zeta potential difference, which demonstrates the quantitative capability of OL-EPM.

  3. Comparative Genomics of Gardnerella vaginalis Strains Reveals Substantial Differences in Metabolic and Virulence Potential

    PubMed Central

    Yeoman, Carl J.; Yildirim, Suleyman; Thomas, Susan M.; Durkin, A. Scott; Torralba, Manolito; Sutton, Granger; Buhay, Christian J.; Ding, Yan; Dugan-Rocha, Shannon P.; Muzny, Donna M.; Qin, Xiang; Gibbs, Richard A.; Leigh, Steven R.; Stumpf, Rebecca; White, Bryan A.; Highlander, Sarah K.; Nelson, Karen E.; Wilson, Brenda A.

    2010-01-01

    Background Gardnerella vaginalis is described as a common vaginal bacterial species whose presence correlates strongly with bacterial vaginosis (BV). Here we report the genome sequencing and comparative analyses of three strains of G. vaginalis. Strains 317 (ATCC 14019) and 594 (ATCC 14018) were isolated from the vaginal tracts of women with symptomatic BV, while Strain 409-05 was isolated from a healthy, asymptomatic individual with a Nugent score of 9. Principal Findings Substantial genomic rearrangement and heterogeneity were observed that appeared to have resulted from both mobile elements and substantial lateral gene transfer. These genomic differences translated to differences in metabolic potential. All strains are equipped with significant virulence potential, including genes encoding the previously described vaginolysin, pili for cytoadhesion, EPS biosynthetic genes for biofilm formation, and antimicrobial resistance systems, We also observed systems promoting multi-drug and lantibiotic extrusion. All G. vaginalis strains possess a large number of genes that may enhance their ability to compete with and exclude other vaginal colonists. These include up to six toxin-antitoxin systems and up to nine additional antitoxins lacking cognate toxins, several of which are clustered within each genome. All strains encode bacteriocidal toxins, including two lysozyme-like toxins produced uniquely by strain 409-05. Interestingly, the BV isolates encode numerous proteins not found in strain 409-05 that likely increase their pathogenic potential. These include enzymes enabling mucin degradation, a trait previously described to strongly correlate with BV, although commonly attributed to non-G. vaginalis species. Conclusions Collectively, our results indicate that all three strains are able to thrive in vaginal environments, and therein the BV isolates are capable of occupying a niche that is unique from 409-05. Each strain has significant virulence potential, although genomic and metabolic differences, such as the ability to degrade mucin, indicate that the detection of G. vaginalis in the vaginal tract provides only partial information on the physiological potential of the organism. PMID:20865041

  4. Gender Differences in Large-Scale Math Assessments: PISA Trend 2000 and 2003

    ERIC Educational Resources Information Center

    Liu, Ou Lydia; Wilson, Mark

    2009-01-01

    Many efforts have been made to determine and explain differential gender performance on large-scale mathematics assessments. A well-agreed-on conclusion is that gender differences are contextualized and vary across math domains. This study investigated the pattern of gender differences by item domain (e.g., Space and Shape, Quantity) and item type

  5. Development of a carbonate platform with potential for large discoveries - an example from Vietnam

    SciTech Connect

    Mayall, M.; Bent, A.; Dale, B. )

    1996-01-01

    In offshore central and southern Vietnam a number of carbonate accumulations can be recognized. Platform carbonates form basin-wide units of carbonate characterized by strong, continuous parallel seismic reflectors. Facies are dominated by bioclastic wackestones with poor-moderate reservoir quality. On the more isolated highs, large buildups developed. These are typically 5-10 km across and 300 m thick. They unconformably overlie the platform carbonate facies which are extensively karstified. In places these are pinnacles, typically 2-5 km across, 300 m+ thick with chaotic or mounded internal seismic facies. The large carbonate buildups are characterized by steep sided slopes with talus cones, reef-margin rims usually developed around only part of the buildup, and a prominent back-stepping geometry. Buildup interior facies form the main potential reservoirs They are dominated by fine to coarse grained coralgal packstones. Fine grained carbonates are associated with deeper water events and multiple karst surfaces can also be identified. Reservoir quality is excellent, largely controlled by extensive dissolution and dolomitization believed to be related to the exposure events. Gas has been found in a number of reservoirs. Heterogeneities can be recognized which could potentially effect production. These include the extensive finer grained facies, cementation or open fissures associated with the karst surfaces, a more cemented reef rim, shallowing upwards facies cycles and faults.

  6. Development of a carbonate platform with potential for large discoveries - an example from Vietnam

    SciTech Connect

    Mayall, M.; Bent, A.; Dale, B.

    1996-12-31

    In offshore central and southern Vietnam a number of carbonate accumulations can be recognized. Platform carbonates form basin-wide units of carbonate characterized by strong, continuous parallel seismic reflectors. Facies are dominated by bioclastic wackestones with poor-moderate reservoir quality. On the more isolated highs, large buildups developed. These are typically 5-10 km across and 300 m thick. They unconformably overlie the platform carbonate facies which are extensively karstified. In places these are pinnacles, typically 2-5 km across, 300 m+ thick with chaotic or mounded internal seismic facies. The large carbonate buildups are characterized by steep sided slopes with talus cones, reef-margin rims usually developed around only part of the buildup, and a prominent back-stepping geometry. Buildup interior facies form the main potential reservoirs They are dominated by fine to coarse grained coralgal packstones. Fine grained carbonates are associated with deeper water events and multiple karst surfaces can also be identified. Reservoir quality is excellent, largely controlled by extensive dissolution and dolomitization believed to be related to the exposure events. Gas has been found in a number of reservoirs. Heterogeneities can be recognized which could potentially effect production. These include the extensive finer grained facies, cementation or open fissures associated with the karst surfaces, a more cemented reef rim, shallowing upwards facies cycles and faults.

  7. Large anti-HER2/neu liposomes for potential targeted intraperitoneal therapy of micrometastatic cancer

    PubMed Central

    Sofou, Stavroula; Enmon, Richard; Palm, Stig; Kappel, Barry; Zanzonico, Pat; McDevitt, Michael R.; Scheinberg, David A.; Sgouros, George

    2011-01-01

    Effective targeting and killing of intraperitoneally disseminated micrometastases remains a challenge. Objective/Methods In this work, we evaluated the potential of antibody-labeled PEGylated large liposomes as vehicles for direct intraperitoneal (i.p.) drug delivery with the aim to enhance the tumor-to-normal organ ratio and to improve the bioexposure of cancer cells to the delivered therapeutics while shifting the toxicities toward the spleen. These targeted liposomes are designed to combine: (1) specific targeting to and internalization by cancer cells mediated by liposome-conjugated tumor-specific antibodies, (2) slow clearance from the peritoneal cavity, and (3) shift of normal organ toxicities from the liver to the spleen due to their relatively large size. Results Conjugation of anti-HER2/neu antibodies to the surface of large (approximately 600 nm in diameter) PEGylated liposomes results in fast, specific binding of targeted liposomes to cancer cells in vitro, followed by considerable cellular internalization. In vivo, after i.p. administration, these liposomes exhibit fast, specific binding to i.p. cancerous tumors. Large liposomes are slowly cleared from the peritoneal cavity, and they exhibit increased uptake by the spleen relative to the liver, while targeted large liposomes demonstrate specific tumor uptake at early times. Although tissue and tumor uptake are greater for cationic liposomes, the tumor-to-liver and spleen-to-liver ratios are similar for both membrane compositions, suggesting a primary role for the liposomes size, compared to the liposomes surface charge. Conclusions The findings of this study suggest that large targeted liposomes administered i.p. could be a potent drug-delivery strategy for locoregional therapy of i.p. micrometastatic tumors. PMID:20070139

  8. Large-rock avalanche deposits, eastern Basin and Range, Utah: Emplacement, diagenesis, and economic potential

    SciTech Connect

    Morris, T.H.; Hebertson, G.F.

    1996-07-01

    Large-rock avalanche deposits are a common component of the basin fill within the extensional tectonic terrain of the Basin and Range; these deposits recently have been interpreted to host oil and gas within the Railroad Valley area of eastern Nevada. Large blocks of brecciated bedrock are a primary component of these avalanche deposits and are potentially excellent oil and gas reservoirs. Our work provides further insight into the emplacement and economic potential of these deposits. Exposed large-rock avalanche deposits of the Miocene Oak City Formation on the western margin of the Canyon Range, Utah, contain coherent breccia blocks up to 3.5 km long, 1 km wide, and 200 m thick. These deposits were derived from the near-vertical dipping bed rock of the adjacent Canyon Range and now are exposed as much as 5.5 km from the range front within the Sevier Desert basin. Emplacement was relatively rapid, as indicated by three well-developed breccia facies within the carbonate breccia blocks. Stratigraphically, from the base the facies include (1) matrix-rich breccia, (2) jigsaw breccia, and (3) crackle breccia. The deposits were cut and segmented by a series of syn-depositional normal faults that developed during late Miocene and post-Miocene extension. Primary porosity was reduced by cement soon after burial. Cathodoluminescence cement patterns indicate that initially the basinward breccia blocks were more deeply buried relative to the water table than the breccia blocks proximal to the Canyon Range. After initial cementation, the basinward blocks were uplifted relative to the water table. Secondary porosity approaches 8% in the carbonate blocks and is greater than 14% within the jigsaw breccia. The size and porosity of these breccia blocks indicate their potential as reservoir targets.

  9. Latency correction of event-related potentials between different experimental protocols

    NASA Astrophysics Data System (ADS)

    Iturrate, I.; Chavarriaga, R.; Montesano, L.; Minguez, J.; Milln, JdR

    2014-06-01

    Objective. A fundamental issue in EEG event-related potentials (ERPs) studies is the amount of data required to have an accurate ERP model. This also impacts the time required to train a classifier for a brain-computer interface (BCI). This issue is mainly due to the poor signal-to-noise ratio and the large fluctuations of the EEG caused by several sources of variability. One of these sources is directly related to the experimental protocol or application designed, and may affect the amplitude or latency of ERPs. This usually prevents BCI classifiers from generalizing among different experimental protocols. In this paper, we analyze the effect of the amplitude and the latency variations among different experimental protocols based on the same type of ERP. Approach. We present a method to analyze and compensate for the latency variations in BCI applications. The algorithm has been tested on two widely used ERPs (P300 and observation error potentials), in three experimental protocols in each case. We report the ERP analysis and single-trial classification. Main results. The results obtained show that the designed experimental protocols significantly affect the latency of the recorded potentials but not the amplitudes. Significance. These results show how the use of latency-corrected data can be used to generalize the BCIs, reducing the calibration time when facing a new experimental protocol.

  10. Generation, migration, and resource potential for hydrocarbons in accretionary subduction systems - a large, unconventional hydrocarbon resource

    SciTech Connect

    Stevenson, A.J. )

    1993-01-01

    Methane and other gaseous and liquid hydrocarbons are common components of accretionary complexes and have been observed in all environments within modern and fossil accretionary accumulations. Methane is generated in this setting by both microbial and thermal processes, but the limited number of samples analyzed prevents an accurate assessment of the relative importance of these two gas generation mechanisms. Large accretionary prisms are geologic settings which, owing to the large amounts of organic detritus cycling through them, represent a large potential source of methane. Organic detritus in accretionary systems is primarily terrestrial in origin and thus gas prone. Variations in the sediment input, thermal structure, fluid flow regime, and structural style of accretionary prisms have a substantial effect on the amount of sediment that enters the gas generation window and on the amount and type of hydrocarbons generated. Factors favorable for maximum evolution of gas include a large, thick accretionary prism, a thick incoming sedimentary section, substantial axial trench sedimentation fed with continental detritus, development of the decollement near the top of the incoming section, substantial underplating, a young subducting plate, and slow to moderate plate convergence rates. On a worldwide basis, long-term methane generation potential is estimated at 1.5x10[sup 10] m[sup 3] (0.5 trillion cubic feet or Tcf) per year in the accretionary subduction setting. No commercial accumulations of gas have yet been identified in this setting; this lack of accumulations implies that much of the gas generated may escape to the oceans and the atmosphere. However, accretionary complexes have not been extensively explored for hydrocarbons, and the trapping of even a small part of the gas generated could result in a substantial commercial resource. 37 refs., 5 figs.

  11. Neuropeptide Y in submucosal ganglia: regional differences in the innervation of guinea-pig large intestine.

    PubMed

    Cunningham, S M; Lees, G M

    1995-11-01

    Since information about possible regional differences in the innervation of the guinea-pig large intestine is incomplete, a comparative study was made of the occurrence of neurones and nerve fibres of the submucosa showing immunoreactivity (IR) to neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP). In addition, a quantitative analysis was made of submucosal neurones in regions of guinea-pig large intestine selected for probable differences in their function. There were two principal findings: First, the density of NPY-IR neurone somata was high in the ascending colon (mean +/- SEM 3148 +/- 464 neurones/cm2; n = 5 animals) and progressively declined in an anal direction, the descending colon having 348 +/- 125 neurones/cm2 (in the same 5 animals); immunoreactive cell bodies were rare in the rectum. The reduced density was also reflected in a fall in the number of NPY-IR neurones/ganglion from 3.0 +/- 0.3 in the ascending colon to 0.5 +/- 0.2 in the descending colon. Second, varicose NPY-IR intraganglionic fibres were a conspicuous feature of the duodenum, caecum, transverse colon, descending colon and rectum, but not of the ileum, ascending colon or distal spiral. Moreover, in the descending colon and rectum the fibres were arranged in a loose 'cobweb' structure around non-NPY-IR neurone somata; in the caecum, there was an apparent paucity of NPY-IR somata but the exceptionally dense intraganglionic varicose fibre network may have obscured NPY-IR somata. In all regions, fibre baskets were rare. In the ascending colon, only 25 +/- 5% of ganglia (compared to 92 +/- 2% of ganglia in the descending colon) showed any intraganglionic nerve fibres; furthermore, when they occurred, these were not of the 'cobweb' type but, rather, they gave the ganglia a speckled appearance. In very immature fetuses at a stage of development when no neuropeptide somata could be found in either the myenteric or submucosal plexuses, many NPY-IR nerve fibres were present in the submucosa with a distribution similar to that of adult guinea pigs. With respect to the density of VIP-IR neurones in the large intestine, there was only a 40% reduction in the number of neurones/cm2 from proximal to distal colon, in contrast to the corresponding 90% reduction in the density of NPY-IR neurones. The number of VIP-IR neurones/ganglion (6.4) and the proportion of ganglia with VIP-IR fibres (> 90%) were constant. It is concluded that the striking regional dissimilarities in (i) the occurrence of NPY-IR neurone somata and (ii) in the disposition of intraganglionic NPY-IR nerve fibres indicate potentially important regional differences in the functions of neuropeptide Y as an antisecretory peptide in the local regulation of chloride transport in the mucosa and as a modulator of ganglionic transmission, respectively. PMID:8801263

  12. Foraging and growth potential of juvenile Chinook Salmon after tidal restoration of a large river delta

    USGS Publications Warehouse

    David, Aaron T.; Ellings, Christopher; Woo, Isa; Simenstad, Charles A.; Takekawa, John Y.; Turner, Kelley L.; Smith, Ashley L.; Takekawa, Jean E.

    2014-01-01

    We evaluated whether restoring tidal flow to previously diked estuarine wetlands also restores foraging and growth opportunities for juvenile Chinook Salmon Oncorhynchus tshawytscha. Several studies have assessed the value of restored tidal wetlands for juvenile Pacific salmon Oncorhynchus spp., but few have used integrative measures of salmon performance, such as habitat-specific growth potential, to evaluate restoration. Our study took place in the Nisqually River delta, Washington, where recent dike removals restored tidal flow to 364 ha of marsh—the largest tidal marsh restoration project in the northwestern contiguous United States. We sampled fish assemblages, water temperatures, and juvenile Chinook Salmon diet composition and consumption rates in two restored and two reference tidal channels during a 3-year period after restoration; these data were used as inputs to a bioenergetics model to compare Chinook Salmon foraging performance and growth potential between the restored and reference channels. We found that foraging performance and growth potential of juvenile Chinook Salmon were similar between restored and reference tidal channels. However, Chinook Salmon densities were significantly lower in the restored channels than in the reference channels, and growth potential was more variable in the restored channels due to their more variable and warmer (2°C) water temperatures. These results indicate that some—but not all—ecosystem attributes that are important for juvenile Pacific salmon can recover rapidly after large-scale tidal marsh restoration.

  13. Chemical and structural indicators for large redox potentials in Fe-based positive electrode materials.

    PubMed

    Melot, Brent C; Scanlon, David O; Reynaud, Marine; Rousse, Gwenalle; Chotard, Jean-Nol; Henry, Marc; Tarascon, Jean-Marie

    2014-07-23

    Li-ion batteries have enabled a revolution in the way portable consumer-electronics are powered and will play an important role as large-scale electrochemical storage applications like electric vehicles and grid-storage are developed. The ability to identify and design promising new positive insertion electrodes will be vital in continuing to push Li-ion technology to its fullest potential. Utilizing a combination of computational tools and structural analysis, we report new indicators which will facilitate the recognition of phases with the desired redox potential. Most importantly of these, we find there is a strong correlation between the presence of Li ions sitting in close-proximity to the redox center of polyanionic phases and the open circuit voltage in Fe-based cathodes. This common structural feature suggests that the bonding associated with Li may have a secondary inductive effect which increases the ionic character of Fe bonds beyond what is typically expected based purely on arguments of electronegativity associated with the polyanionic group. This correlation is supported by ab initio calculations which show the Bader charge increases (reflecting an increased ionicity) in a nearly linear fashion with the experimental cell potentials. These features are demonstrated to be consistent across a wide variety of compositions and structures and should help to facilitate the design of new, high-potential, and environmentally sustainable insertion electrodes. PMID:24588538

  14. Numerical solution of differential-difference equations in large intervals using a Taylor collocation method

    NASA Astrophysics Data System (ADS)

    Tirani, M. Dadkhah; Sohrabi, F.; Almasieh, H.; Kajani, M. Tavassoli

    2015-10-01

    In this paper, a collocation method based on Taylor polynomials is developed for solving systems linear differential-difference equations with variable coefficients defined in large intervals. By using Taylor polynomials and their properties in obtaining operational matrices, the solution of the differential-difference equation system with given conditions is reduced to the solution of a system of linear algebraic equations. We first divide the large interval into M equal subintervals and then Taylor polynomials solutions are obtained in each interval, separately. Some numerical examples are given and results are compared with analytical solutions and other techniques in the literature to demonstrate the validity and applicability of the proposed method.

  15. Variations in Environmental Signals in Tree-Ring Indices in Trees with Different Growth Potential

    PubMed Central

    Hafner, Polona; Gričar, Jožica; Skudnik, Mitja; Levanič, Tom

    2015-01-01

    We analysed two groups of Quercus robur trees, growing at nearby plots with different micro-location condition (W-wet and D-dry) in the floodplain Krakovo forest, Slovenia. In the study we compared the growth response of two different tree groups to environmental variables, the potential signal stored in earlywood (EW) structure and the potential difference of the information stored in carbon isotope discrimination of EW and latewood (LW). For that purpose EW and LW widths and carbon isotope discrimination for the period 1970–2008 AD were measured. EW and LW widths were measured on stained microscopic slides and chronologies were standardised using the ARSTAN program. α-cellulose was extracted from pooled EW and LW samples and homogenized samples were further analysed using an elemental analyser and IRMS. We discovered that W oaks grew significantly better over the whole analysed period. The difference between D and W oaks was significant in all analysed variables with the exception of stable carbon isotope discrimination in latewood. In W oaks, latewood widths correlated with summer (June to August) climatic variables, while carbon isotope discrimination was more connected to River Krka flow during the summer. EW discrimination correlated with summer and autumn River Krka flow of the previous year, while latewood discrimination correlated with flow during the current year. In the case of D oaks, the environmental signal appears to be vague, probably due to less favourable growth conditions resulting in markedly reduced increments. Our study revealed important differences in responses to environmental factors between the two oak groups of different physiological conditions that are preconditioned by environmental stress. Environmental information stored in tree-ring features may vary, even within the same forest stand, and largely depends on the micro-environment. Our analysis confirmed our assumptions that separate EW and LW analysis of widths and carbon isotope discrimination provides complementary information in Q. robur dendroecology. PMID:26619344

  16. Variations in Environmental Signals in Tree-Ring Indices in Trees with Different Growth Potential.

    PubMed

    Hafner, Polona; Gri?ar, Joica; Skudnik, Mitja; Levani?, Tom

    2015-01-01

    We analysed two groups of Quercus robur trees, growing at nearby plots with different micro-location condition (W-wet and D-dry) in the floodplain Krakovo forest, Slovenia. In the study we compared the growth response of two different tree groups to environmental variables, the potential signal stored in earlywood (EW) structure and the potential difference of the information stored in carbon isotope discrimination of EW and latewood (LW). For that purpose EW and LW widths and carbon isotope discrimination for the period 1970-2008 AD were measured. EW and LW widths were measured on stained microscopic slides and chronologies were standardised using the ARSTAN program. ?-cellulose was extracted from pooled EW and LW samples and homogenized samples were further analysed using an elemental analyser and IRMS. We discovered that W oaks grew significantly better over the whole analysed period. The difference between D and W oaks was significant in all analysed variables with the exception of stable carbon isotope discrimination in latewood. In W oaks, latewood widths correlated with summer (June to August) climatic variables, while carbon isotope discrimination was more connected to River Krka flow during the summer. EW discrimination correlated with summer and autumn River Krka flow of the previous year, while latewood discrimination correlated with flow during the current year. In the case of D oaks, the environmental signal appears to be vague, probably due to less favourable growth conditions resulting in markedly reduced increments. Our study revealed important differences in responses to environmental factors between the two oak groups of different physiological conditions that are preconditioned by environmental stress. Environmental information stored in tree-ring features may vary, even within the same forest stand, and largely depends on the micro-environment. Our analysis confirmed our assumptions that separate EW and LW analysis of widths and carbon isotope discrimination provides complementary information in Q. robur dendroecology. PMID:26619344

  17. Differences in seed rain composition in small and large fragments in the northeast Brazilian Atlantic Forest.

    PubMed

    Knrr, U C; Gottsberger, G

    2012-09-01

    Tropical forests are seriously threatened by fragmentation and habitat loss. The impact of fragment size and forest configuration on the composition of seed rain is insufficiently studied. For the present study, seed rain composition of small and large forest fragments (8-388?ha) was assessed in order to identify variations in seed abundance, species richness, seed size and dispersal mode. Seed rain was documented during a 1-year period in three large and four small Atlantic Forest fragments that are isolated by a sugarcane matrix. Total seed rain included 20,518 seeds of 149 species of trees, shrubs, palms, lianas and herbs. Most species and seeds were animal-dispersed. A significant difference in the proportion of seeds and species within different categories of seed size was found between small and large fragments. Small fragments received significantly more very small-sized seeds (<0.3?cm) and less large-seeded species (>1.5?cm) that were generally very rare, with only one species in small and eight in large fragments. We found a negative correlation between the inflow of small-sized seeds and the percentage of forest cover. Species richness was lower in small than in large fragments, but the difference was not very pronounced. Given our results, we propose changing plant species pools through logging, tree mortality and a high inflow of pioneer species and lianas, especially in small forest fragments and areas with low forest cover. Connecting forest fragments through corridors and reforestation with local large-seeded tree species may facilitate the maintenance of species diversity. PMID:22372687

  18. Potential for on-orbit manufacture of large space structures using the pultrusion process

    NASA Technical Reports Server (NTRS)

    Wilson, Maywood L.; Macconochie, Ian O.; Johnson, Gary S.

    1987-01-01

    On-orbit manufacture of lightweight, high-strength, advanced-composite structures using the pultrusion process is proposed. This process is adaptable to a zero-gravity environment by using preimpregnated graphite-fiber reinforcement systems. The reinforcement material is preimpregnated with a high-performance thermoplastic resin at a ground station, is coiled on spools for compact storage, and is transported into Earth orbit. A pultrusion machine is installed in the Shuttle cargo bay from which very long lengths of the desired structure is fabricated on-orbit. Potential structural profiles include rods, angles, channels, hat sections, tubes, honeycomb-cored panels, and T, H, and I beams. A potential pultrudable thermoplastic/graphite composite material is presented as a model for determining the effect on Earth-to-orbit package density of an on-orbit manufacture, the package density is increased by 132 percent, and payload volume requirement is decreased by 56.3 percent. The fabrication method has the potential for on-orbit manufacture of structural members for space platforms, large space antennas, and long tethers.

  19. Automated system for identifying potential dosage problems at a large university hospital.

    PubMed

    McMullin, S T; Reichley, R M; Kahn, M G; Dunagan, W C; Bailey, T C

    1997-03-01

    A hospital's experience with an automated system for screening drug orders for potential dosage problems is described. DoseChecker was developed by the hospital pharmacy department in collaboration with a local university. Pharmacy, laboratory, and patient demographic data are transferred nightly from the hospital's mainframe system to a database server; DoseChecker uses these data and user-defined rules to (1) identify patients receiving any of 35 targeted medications, (2) evaluate the appropriateness of current dosages, and (3) generate alerts for patients potentially needing dosage adjustments. The alert reports are distributed to satellite pharmacists, who evaluate each patient's condition and make recommendations to physicians as needed. One of the system's primary purposes is to calculate creatinine clearance and verify that dosages are properly adjusted for renal function. Between May and October 1995, the system electronically screened 28,528 drug orders and detected potential dosage problems in 2859 (10%). The system recommended a lower daily dose in 1992 cases (70%) and a higher daily dose in 867 (30%). Pharmacists contacted physicians concerning 1163 (41%) of the 2859 alerts; in 868 cases (75%), the physicians agreed to adjust the dosage. The most common dosage problem identified was failure to adjust dosages on the basis of declining renal function. An automated system provided an efficient method of identifying inappropriate dosages at a large university hospital. PMID:9066863

  20. Infants Use Different Mechanisms to Make Small and Large Number Ordinal Judgments

    ERIC Educational Resources Information Center

    vanMarle, Kristy

    2013-01-01

    Previous research has shown indirectly that infants may use two different mechanisms-an object tracking system and an analog magnitude mechanism--to represent small (less than 4) and large (greater than or equal to 4) numbers of objects, respectively. The current study directly tested this hypothesis in an ordinal choice task by presenting 10- to

  1. Electrolyte and Haemogram changes post large volume liposuction comparing two different tumescent solutions

    PubMed Central

    Vivek, Kumar; Amiti, Shah; Shivshankar, Saha; Lalit, Choudhary

    2014-01-01

    Background: The most common definitions of large volume liposuction refer to total 5 l volume aspiration during a single procedure (fat plus wetting solution). Profound haemodynamic and metabolic alterations can accompany large volume liposuction. Due to paucity of literature on the effect of different tumescent solutions on the electrolyte balance and haematological changes during large volume liposuction, we carried out this study using two different wetting solutions to study the same. Materials and Methods: Total 30 patients presenting with varying degrees of localized lipodystrophy in different body regions were enrolled for the study. Prospective randomized controlled trial was conducted by Department of Plastic and Cosmetic Surgery, Sir Ganga Ram Hospital, New Delhi from January 2011 to June 2012. Patients were randomized into two groups of 15 patients each by using computer generated random numbers. Tumescent formula used for Group A (normal saline [NS]) was our modification of Klein's Formula and Tumescent formula used for Group B (ringer lactate [RL]) was our modification of Hunstadt's formula. Serum electrolytes and hematocrit levels were done at preinduction, immediate postoperative period and postoperative day 1. Result: Statistical analysis was performed using SPSS software version 15.0. Which showed statistically significant electrolytes and hematocrit changes occur during large volume liposuction. Conclusion: Statistically significant electrolytes and hematocrit changes occur during large volume liposuction and patients should be kept under observation of anaesthesist for at least 24 h. Patients require strict monitoring of vital parameters and usually Intensive Care Unit is not required. There was no statistical difference in the electrolyte changes using NS or RL as tumescent solution and both solutions were found safe for large volume liposuction. PMID:25593425

  2. Big data and large sample size: a cautionary note on the potential for bias.

    PubMed

    Kaplan, Robert M; Chambers, David A; Glasgow, Russell E

    2014-08-01

    A number of commentaries have suggested that large studies are more reliable than smaller studies and there is a growing interest in the analysis of "big data" that integrates information from many thousands of persons and/or different data sources. We consider a variety of biases that are likely in the era of big data, including sampling error, measurement error, multiple comparisons errors, aggregation error, and errors associated with the systematic exclusion of information. Using examples from epidemiology, health services research, studies on determinants of health, and clinical trials, we conclude that it is necessary to exercise greater caution to be sure that big sample size does not lead to big inferential errors. Despite the advantages of big studies, large sample size can magnify the bias associated with error resulting from sampling or study design. PMID:25043853

  3. Myosin heavy chain composition of different skeletal muscles in Large White and Meishan pigs.

    PubMed

    Lefaucheur, L; Milan, D; Ecolan, P; Le Callennec, C

    2004-07-01

    Four major sarcomeric myosin heavy chains (MyHC) (i.e., I, IIa, IIx, and IIb) are expressed in pig skeletal muscle during postnatal development. The objective of the current study was to compare MyHC composition at mRNA and protein levels in LM, a fast-twitch glycolytic muscle, and rhomboideus (RM), a mixed slow- and fast-twitch oxido-glycolytic muscle, between two pig breeds exhibiting dramatic differences in postnatal muscle growth and meat quality. Eight Large White (LW) and eight Meishan (MS) females were fed under the same standard conditions, and slaughtered at an average BW of 62 kg (131 and 142 d in LW and MS pigs, respectively). In addition to conventional fiber typing by histoenzymology, MyHC composition was analyzed by combining immunocytochemistry, in situ hybridization, and a newly developed real-time PCR assay. Enzyme activities of lactate dehydrogenase, citrate synthase, and beta-hydroxy-acyl-CoA-dehydrogenase were used as markers of glycolytic, oxidative and beta-oxidation capacities, respectively. Results showed that conventional fiber typing in three classes by histoenzymology was insufficient in LM. For the first time, four monoclonal antibodies specific of each MyHC isoform, working in immunocytochemistry, were used. Our results are consistent with the sequential I<-->IIa<-->IIx<-->IIb MyHC transition rule. Breed effect on MyHC composition differed between muscle types. In LM of MS pigs, a shift from IIb to IIx, and to a lesser extent, to IIa, occurred without affecting type I MyHC. In RM, where IIb is absent, a shift from IIx to type I occurred, with a slight decrease in the IIa isoform. Effects were very similar at the mRNA and protein levels, suggesting a transcriptional regulation. In both muscles, MS pigs exhibited a decrease in the relative fiber type specific expression of the fastest isoform (i.e., IIb in LM and IIx in RM). The shift toward a slower phenotype in MS pigs was consistent with a less glycolytic and more oxidative metabolism, potentially using more lipids as fuel. A dramatic increase in cross-sectional area of type I fibers in RM (+27%) and a decrease in that of the fastest IIb fibers in LM (-25%) were observed in MS pigs. Overall, interpretation of earlier data regarding muscle fiber type has been flawed by inaccurate fiber typing in most pig skeletal muscles. PMID:15309939

  4. Contribution potential of glaciers to water availability in different climate regimes

    PubMed Central

    Kaser, Georg; Grohauser, Martin; Marzeion, Ben

    2010-01-01

    Although reliable figures are often missing, considerable detrimental changes due to shrinking glaciers are universally expected for water availability in river systems under the influence of ongoing global climate change. We estimate the contribution potential of seasonally delayed glacier melt water to total water availability in large river systems. We find that the seasonally delayed glacier contribution is largest where rivers enter seasonally arid regions and negligible in the lowlands of river basins governed by monsoon climates. By comparing monthly glacier melt contributions with population densities in different altitude bands within each river basin, we demonstrate that strong human dependence on glacier melt is not collocated with highest population densities in most basins. PMID:21059938

  5. Carbon dioxide recycling: emerging large-scale technologies with industrial potential.

    PubMed

    Quadrelli, Elsje Alessandra; Centi, Gabriele; Duplan, Jean-Luc; Perathoner, Siglinda

    2011-09-19

    This Review introduces this special issue of ChemSusChem dedicated to CO(2) recycling. Its aim is to offer an up-to-date overview of CO(2) chemical utilization (inorganic mineralization, organic carboxylation, reduction reactions, and biochemical conversion), as a continuation and extension of earlier books and reviews on this topic, but with a specific focus on large-volume routes and projects/pilot plants that are currently emerging at (pre-)industrial level. The Review also highlights how some of these routes will offer a valuable opportunity to introduce renewable energy into the existing energy and chemical infrastructure (i.e., "drop-in" renewable energy) by synthesis of chemicals from CO(2) that are easy to transport and store. CO(2) conversion therefore has the potential to become a key pillar of the sustainable and resource-efficient production of chemicals and energy from renewables. PMID:21922677

  6. Study on mixis potential of rotifer resting eggs ( Brachionus plicatilis) with different collection times and different preservation periods

    NASA Astrophysics Data System (ADS)

    Zhou, Li; Zheng, Yan; Xiang, Jian-Hai

    2001-09-01

    The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985 1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.

  7. Large climate-moderating envelopes for enclosed structures: a preliminary evaluation of energy conservation potential

    SciTech Connect

    Wendt, R.L.; Giles, G.E.; Park, J.E.

    1981-12-01

    An investigation was made of the basic impacts of putting a large secondary enclosure around a number of functions and thereby creating a Large Climate Moderating Envelope (LCME). This study is a preliminary estimate of the energy conservation benefits of an LCME. A hypothetical LMCE design was chosen and a coupled fluid dynamic and energy transport analysis was performed to estimate the energy conservation potential of this design. The heat transfer models included insolation, outside air temperature and wind, thermal radiation exchange with the sky, and between the fabric and ground and thermal storage in the earth mass beneath the LCME. The energy transported within the fluid by the buoyancy driven circulation was modeled as an incompressible fluid utilizing the Boussinesq approximation. The climatic conditions were assumed to vary in smooth repeating daily cycles. The numerical simulation of climatic variation was continued until the results within the LCME achieved a repeating daily cycle. The results for selected seasonally characteristic days were utilized to estimate the annual energy consumption of structures within an LCME relative to similar structures exposed to the exterior environment. The relative annual energy savings for summer-dominated climates was estimated to be approx. 70%. The energy savings for a winter-dominated climate LCME were estimated to be somewhat smaller but the LCME concept could offer significant benefits for agricultural applications for this type of climate.

  8. Potential for a large earthquake rupture of the San Ramn fault in Santiago, Chile

    NASA Astrophysics Data System (ADS)

    Vargas Easton, G.; Klinger, Y.; Rockwell, T. K.; Forman, S. L.; Rebolledo, S.; Lacassin, R.; Armijo, R.

    2013-12-01

    The San Ramn fault is an active west-vergent thrust fault system located along the eastern border of Santiago, capital of Chile, at the foot of the main Andes Cordillera. This is part of the continental-scale West Andean Thrust, at the western slope of the Andean orogen. The fault system is constituted by fault segments in the order of 10-15 km length, evidenced by conspicuous 3-over 100 m height fault scarps systematically located along the fault trace. This evidence Quaternary faulting activity, which together with the geometry, structure and geochronological data support slip rate estimations in the order of ~0.4 mm/year. To probe seismic potential for the west flank of the Andes in front of Santiago, we excavated and analyzed a trench across a prominent-young fault scarp. Together with geochronological data from Optically Stimulated Luminiscence complemented by radiocarbon ages, our paleoseismic results demonstrate recurrent late Quaternary faulting along this structure, with nearly 5 m of displacement in each event. With the last large earthquake nearly 8,000-9,000 years ago and two ruptures within the past 17,000-19,000 years ago, the San Ramon fault appears ripe for another large earthquake up to M7.5 in the near future, making Santiago another major world city at significant risk.

  9. Differences between images of large adenoma and protruding type of gallbladder carcinoma.

    PubMed

    Jin, Wangxun; Zhang, Chengwu; He, Xiaodong; Xu, Yuyun; Wang, Li; Zhao, Zhongsheng

    2013-05-01

    The aim of this study was to investigate the differences between images of large adenoma of the gallbladder and the protruding type carcinoma of the gallbladder. A retrospective study was performed on 130 patients who underwent cholecystectomy or biopsy for gallbladder polypoid lesions larger than 10 mm; among them, 20 patients were malignant and 110 patients were benign. Patients' details including ultrasonography (US), computed tomography (CT) and magnetic resonance (MR) findings were analyzed. All patients whose lesions were >15 mm by US, had CT or MR scans to further determine the nature of the lesion; two patients who were suspected to have a malignant lesion due to their large tumor size were benign by histological examination. Distinct differences were found between large adenoma and protruding type of gallbladder carcinoma. There were distinct differences between adenomas and the protruding type gallbladder cancers, and there was a pathological basis for the differences. Benign tumors had a more homogeneous texture, had spaces between the tumor and the gallbladder wall and a relatively normal configuration of the gallbladder wall. Based on these findings, certain lesions could be definitively diagnosed as benign adenomas and could help in treatment strategy. PMID:23760294

  10. Toward large N thermal QCD from dual gravity: The heavy quarkonium potential

    SciTech Connect

    Mia, Mohammed; Dasgupta, Keshav; Gale, Charles; Jeon, Sangyong

    2010-07-15

    We continue our study on the gravity duals for strongly coupled large N QCD with fundamental flavors both at zero and nonzero temperatures. The gravity dual at zero temperature captures the logarithmic runnings of the coupling constants at far IR and the almost conformal, albeit strongly coupled, behavior at the UV. The full UV completion of gauge theory is accomplished in the gravity side by attaching an anti-de Sitter cap to the IR geometry described in our previous work. Attaching such an anti-de Sitter cap is highly nontrivial because it amounts to finding the right interpolating geometry and sources that take us from a gravity solution with nonzero three-form fluxes to another one that has almost vanishing three-form fluxes. In this paper we give a concrete realization of such a scenario, completing the program advocated in our earlier paper. One of the main advantages of having such a background, in addition to providing a dual description of the required gauge theory, is the absence of Landau poles and consequently the UV divergences of the Wilson loops. The potential for the heaviest fundamental quark-antiquark pairs, which are like the heavy quarkonium states in realistic QCD, can be computed and their linear behavior at large separations and zero temperature could be demonstrated. At small separations the expected Coulombic behavior appears to dominate. On the other hand, at nonzero temperatures interesting properties like heavy quarkonium-type suppressions and melting are shown to emerge from our gravity dual. We provide some discussions of the melting temperature and compare our results with the charmonium spectrum and lattice simulations. We argue that, in spite of the large N nature of our construction, certain model-independent predictions can be made.

  11. The potential relevance of the endocannabinoid, 2-arachidonoylglycerol, in diffuse large B-cell lymphoma

    PubMed Central

    Zhang, Jianqing; Medina-Cleghorn, Daniel; Bernal-Mizrachi, Leon; Bracci, Paige M.; Hubbard, Alan; Conde, Lucia; Riby, Jacques; Nomura, Daniel K.; Skibola, Christine F.

    2016-01-01

    Diffuse large B-cell lymphoma is an aggressive, genetically heterogenerous disease and the most common type of non-Hodgkin lymphoma among adults. To gain further insights into the etiology of DLBCL and to discover potential disease-related factors, we performed a serum lipid analysis on a subset of individuals from a population-based NHL case-control study. An untargeted mass-spectrometry-based metabolomics platform was used to analyze serum samples from 100 DLBCL patients and 100 healthy matched controls. Significantly elevated levels of the endocannabinoid, 2-arachidonoylglycerol (2-AG), were detected in the serum of DLBCL patients (121%, P < 0.05). In the male controls, elevated 2-AG levels were observed in those who were overweight (BMI ≥ 25 - < 30 kg/m2; 108%, P < 0.01) and obese (BMI ≥ 30 kg/m2; 118%, P < 0.001) compared to those with a BMI < 25 kg/m2. DLBCL cell lines treated with exogenous 2-AG across a range of concentrations, exhibited heterogenous responses: proliferation rates were markedly higher in 4 cell lines by 22%-68% (P < 0.001) and lower in 8 by 20%-75% (P < 0.001). The combined findings of elevated 2-AG levels in DLBCL patients and the proliferative effects of 2-AG on a subset of DLBCL cell lines suggests that 2-AG may play a potential role in the pathogenesis or progression of a subset of DLBCLs. PMID:26973858

  12. Fabrication of large size graphene and Ti- MWCNTs/ large size graphene composites: their photocatalytic properties and potential application

    NASA Astrophysics Data System (ADS)

    Ullah, Kefayat; Oh, Won-Chun

    2015-09-01

    Large size graphene (LSG) and multiwall carbon nanotubes (MWCNTs) on LSG were synthesized on a copper surface via chemical vapor deposition (CVD) at low temperature and normal pressure. The LSG were formed through an easy chemical cyclic reaction in which liquid benzene was heated to a temperature below its boiling point to create benzene vapors as graphene precursor material. The reaction mechanism was observed, and the time-dependent analysis of the reaction revealed that mounds of the carbon nanotubes had grown as a result of the island that was found on the LSG sheet. The implications of the mechanism that we have introduced were investigated by coating a titanium sheet on the MWCNTs/LSG and LSG on the semiconductor electronic device. The photonic response was observed to be markedly high, which can be attributed to the positive synergetic effect between the Ti and LSG sheet of our prepared composites.

  13. Fabrication of large size graphene and Ti- MWCNTs/ large size graphene composites: their photocatalytic properties and potential application

    PubMed Central

    Ullah, Kefayat; Oh, Won-Chun

    2015-01-01

    Large size graphene (LSG) and multiwall carbon nanotubes (MWCNTs) on LSG were synthesized on a copper surface via chemical vapor deposition (CVD) at low temperature and normal pressure. The LSG were formed through an easy chemical cyclic reaction in which liquid benzene was heated to a temperature below its boiling point to create benzene vapors as graphene precursor material. The reaction mechanism was observed, and the time-dependent analysis of the reaction revealed that mounds of the carbon nanotubes had grown as a result of the island that was found on the LSG sheet. The implications of the mechanism that we have introduced were investigated by coating a titanium sheet on the MWCNTs/LSG and LSG on the semiconductor electronic device. The photonic response was observed to be markedly high, which can be attributed to the positive synergetic effect between the Ti and LSG sheet of our prepared composites. PMID:26384216

  14. Fabrication of large size graphene and Ti- MWCNTs/ large size graphene composites: their photocatalytic properties and potential application.

    PubMed

    Ullah, Kefayat; Oh, Won-Chun

    2015-01-01

    Large size graphene (LSG) and multiwall carbon nanotubes (MWCNTs) on LSG were synthesized on a copper surface via chemical vapor deposition (CVD) at low temperature and normal pressure. The LSG were formed through an easy chemical cyclic reaction in which liquid benzene was heated to a temperature below its boiling point to create benzene vapors as graphene precursor material. The reaction mechanism was observed, and the time-dependent analysis of the reaction revealed that mounds of the carbon nanotubes had grown as a result of the island that was found on the LSG sheet. The implications of the mechanism that we have introduced were investigated by coating a titanium sheet on the MWCNTs/LSG and LSG on the semiconductor electronic device. The photonic response was observed to be markedly high, which can be attributed to the positive synergetic effect between the Ti and LSG sheet of our prepared composites. PMID:26384216

  15. Intra- and Interspecific Differences in Diet Quality and Composition in a Large Herbivore Community

    PubMed Central

    Redjadj, Claire; Darmon, Galle; Maillard, Daniel; Chevrier, Thierry; Bastianelli, Denis; Verheyden, Hlne; Loison, Anne; Sad, Sonia

    2014-01-01

    Species diversity in large herbivore communities is often explained by niche segregation allowed by differences in body mass and digestive morphophysiological features. Based on large number of gut samples in fall and winter, we analysed the temporal dynamics of diet composition, quality and interspecific overlap of 4 coexisting mountain herbivores. We tested whether the relative consumption of grass and browse differed among species of different rumen types (moose-type and intermediate-type), whether diet was of lower quality for the largest species, whether we could identify plant species which determined diet quality, and whether these plants, which could be key-food-resources were similar for all herbivores. Our analyses revealed that (1) body mass and rumen types were overall poor predictors of diet composition and quality, although the roe deer, a species with a moose-type rumen was confirmed as an obligatory non grazer, while red deer, the largest species, had the most lignified diet; (2) diet overlap among herbivores was well predicted by rumen type (high among species of intermediate types only), when measured over broad plant groups, (3) the relationship between diet composition and quality differed among herbivore species, and the actual plant species used during winter which determined the diet quality, was herbivore species-specific. Even if diets overlapped to a great extent, the species-specific relationships between diet composition and quality suggest that herbivores may select different plant species within similar plant group types, or different plant parts and that this, along with other behavioural mechanisms of ecological niche segregation, may contribute to the coexistence of large herbivores of relatively similar body mass, as observed in mountain ecosystems. PMID:24586233

  16. Feedback processing in adolescence: an event-related potential study of age and gender differences.

    PubMed

    Grose-Fifer, Jillian; Migliaccio, Renee; Zottoli, Tina M

    2014-01-01

    Adolescence has frequently been characterized as a period of increased risk taking, which may be largely driven by maturational changes in neural areas that process incentives. To investigate age- and gender-related differences in reward processing, we recorded event-related potentials (ERPs) from 80 participants in a gambling game, in which monetary wins and losses were either large or small. We measured two ERP components: the feedback-related negativity (FRN) and the feedback P3 (fP3). The FRN was sensitive to the size of a win in both adult (aged 23-35 years) and adolescent (aged 13-17 years) males, but not in females. Small wins appeared to be less rewarding for males than for females, which may in part explain more approach-driven behavior in males in general. Furthermore, adolescent boys showed both delayed FRNs to high losses and less differentiation in FRN amplitude between wins and losses in comparison to girls. The fP3, which is thought to index the salience of the feedback at a more conscious level than the FRN, was also larger in boys than in girls. Taken together, these results imply that higher levels of risk taking that are commonly reported in adolescent males may be driven both by hypersensitivity to high rewards and insensitivity to punishment or losses. PMID:24853058

  17. Detecting and developing youth athlete potential: different strokes for different folks are warranted.

    PubMed

    Suppiah, Haresh T; Low, Chee Yong; Chia, Michael

    2015-07-01

    Sport talent identification and development (TI and TD) in youth continues to attract strong interest among coaches, sport scientists and sport administrators. TI for sport in youth with the anticipation of future elite level sport achievement is both an art and a science, and is strongly influenced by within athlete and extraneous-to-athlete factors (ecosystem of support or the lack of). The returns from investment on current TI and TD models of sport in youth are subpar in that few continue in the sport to achieve podium positions at the elite sport level in adulthood. Why, where and how one succeeds in sport, and what that success means to the athlete and stakeholders are dependent on the culture and context of the country. We advocate harnessing the power of sport to help in youth development, to be holistic in its nurturance, to allow for individual idiosyncratic expressions of the athletes, to provide for talent transfer across sport, and to facilitate key stakeholders to 'join' hands to work for the common interest and understanding for as many youth and adults so as to provide them with opportunitiesthrough support and coaching to compete at the different levels of competition in sport. Governments, policy makers and administrators of sport must decide,within their specific circumstances, if TI and TD in sport in youth is serving a meaningful purpose and is a viable return on investment; in short, is it mission possible or is it a quest for the Holy Grail for a podium finish in elite level sport competition? PMID:25907182

  18. Large-scale purification and long-term stability of human butyrylcholinesterase: a potential bioscavenger drug.

    PubMed

    Grunwald, J; Marcus, D; Papier, Y; Raveh, L; Pittel, Z; Ashani, Y

    1997-03-27

    Butyrylcholinesterase from human plasma (HuBChE) is a potential drug candidate for detoxification of certain harmful chemicals that contain carboxylic or phosphoric acid ester bonds. Large quantities of purified HuBChE, displaying a high stability upon long-term storage, are required for the evaluation of its therapeutic capacity and its pharmaceutical properties. Several modifications of a previously reported procedure enabled us to purify the enzyme > 15,000-fold from pools of up to 100 1 of human plasma. The three-step procedure is based on precipitation of plasma proteins by ammonium sulfate (step I) and batch adsorption of HuBChE on procainamide-Sepharose 4B gel (step II). Ammonium sulfate was also employed in the third stage to fractionate the final product from procainamide-containing HuBChE solution. The overall yield (63%) of electrophoretically pure enzyme was significantly higher than that previously reported (34%) for the purification of HuBChE from 12.5 1 of plasma or from 5 kg of Cohn fraction IV-4. Purified HuBChE was stored at 5 degrees C in 10 mM phosphate buffer (pH 7.4) containing 1 mM EDTA and 0.02% NaN3. The specific activity, protein migration on gel electrophoresis, thermostability at 54 degrees C and the mean residence time in the circulation of mice remained essentially constant for at least 46 months. The modifications introduced can provide large quantities of purified enzyme that maintains its activity and bioavailability properties for several years. PMID:9178088

  19. VH gene structure predicts a large potential anti-insulin repertoire.

    PubMed

    Mitchell, H C; Thomas, J W

    1995-04-01

    The majority of insulin antibodies derived from immunization are IgG antibodies that cross-react extensively with the autologous hormone. To examine the relationship between VH genes expressed by such self-reactive antibodies and their germline (non-rearranged) counterparts, we used the polymerase chain reaction (PCR) to amplify and isolate the germline progenitors of anti-insulin VH genes derived from BALB/c mice immunized with beef or human insulin. Results indicate that two anti-insulin mAbs (123 and 124) express VH genes which arise from a small subset of the J558 gene family and are highly homologous to the VH gene used by the murine CD5 + B-cell tumor, BCL1. The anti-insulin IgG mAb 127 belongs to the VH-VIII (Vgam 3.2) family and the amplification and isolation of germline VH genes from this small family precisely identified only two somatic mutation events in the CDRH2 of mAb 127. Another anti-insulin mAb, 133, also shows two replacement substitutions in the CDRHs when compared to the germline encoded anti-dextran antibody 19.1.2. These findings indicate that the IgG response to this small self-protein uses multiple VH genes which are largely germline encoded with only a low level of somatic mutation in their CDRHs. Additionally, analysis of N-segment additions in CDRH3s indicates anti-insulin B cells may originate from both early (fetal) and adult repertoires. These data are consistent with the concept that the mechanisms of clonal anergy or deletion do not regulate anti-insulin B cells and indicate that there is a large potential VH gene repertoire for insulin. PMID:7537854

  20. The Potential of Unmanned Aerial Vehicle for Large Scale Mapping of Coastal Area

    NASA Astrophysics Data System (ADS)

    Darwin, N.; Ahmad, A.; Zainon, O.

    2014-02-01

    Many countries in the tropical region are covered with cloud for most of the time, hence, it is difficult to get clear images especially from high resolution satellite imagery. Aerial photogrammetry can be used but most of the time the cloud problem still exists. Today, this problem could be solved using a system known as unmanned aerial vehicle (UAV) where the aerial images can be acquired at low altitude and the system can fly under the cloud. The UAV system could be used in various applications including mapping coastal area. The UAV system is equipped with an autopilot system and automatic method known as autonomous flying that can be utilized for data acquisition. To achieve high resolution imagery, a compact digital camera of high resolution was used to acquire the aerial images at an altitude. In this study, the UAV system was employed to acquire aerial images of a coastal simulation model at low altitude. From the aerial images, photogrammetric image processing was executed to produce photogrammetric outputs such a digital elevation model (DEM), contour line and orthophoto. In this study, ground control point (GCP) and check point (CP) were established using conventional ground surveying method (i.e total station). The GCP is used for exterior orientation in photogrammetric processes and CP for accuracy assessment based on Root Mean Square Error (RMSE). From this study, it was found that the UAV system can be used for large scale mapping of coastal simulation model with accuracy at millimeter level. It is anticipated that the same system could be used for large scale mapping of real coastal area and produces good accuracy. Finally, the UAV system has great potential to be used for various applications that require accurate results or products at limited time and less man power.

  1. Potential biases in the detection of planetary systems with large transit timing variations

    NASA Astrophysics Data System (ADS)

    Garca-Melendo, E.; Lpez-Morales, M.

    2011-10-01

    The transit timing variations (TTVs) technique provides a powerful tool to detect additional planets in transiting exoplanetary systems. In this Letter, we show how transiting planets with significant TTVs can be systematically missed, or catalogued as false positives, by current transit search algorithms, unless they are in multitransit systems. If the period of the TTVs, PTTV, is longer than the time baseline of the observations and its amplitude, ATTV, is larger than the timing precision limit of the data, transiting planet candidates are still detected, but with incorrect ephemerides. Therefore, they will be discarded during follow-up. When PTTV is shorter than the time baseline of the observations and ATTV is sufficiently large, constant period search algorithms find an average period for the system, which results in altered transit durations and depths in the folded light curves. Those candidates can get subsequently discarded as eclipsing binaries, grazing eclipses or blends. Also, for large enough ATTV values, the transits can get fully occulted by the photometric dispersion of the light curves. These detection biases could explain the observed statistical differences between the frequency of multiple systems among planets detected via other techniques and those detected via transits. We suggest that new transit search algorithms allowing for non-constant period planets should be implemented.

  2. On the Definition of Surface Potentials for Finite-Difference Operators

    NASA Technical Reports Server (NTRS)

    Tsynkov, S. V.; Bushnell, Dennis M. (Technical Monitor)

    2001-01-01

    For a class of linear constant-coefficient finite-difference operators of the second order, we introduce the concepts similar to those of conventional single- and double-layer potentials for differential operators. The discrete potentials are defined completely independently of any notion related to the approximation of the continuous potentials on the grid. We rather use all approach based on differentiating, and then inverting the differentiation of a function with surface discontinuity of a particular kind, which is the most general way of introducing surface potentials in the theory of distributions. The resulting finite-difference "surface" potentials appear to be solutions of the corresponding continuous potentials. Primarily, this pertains to the possibility of representing a given solution to the homogeneous equation on the domain as a variety of surface potentials, with the density defined on the domain's boundary. At the same time the discrete surface potentials can be interpreted as one specific realization of the generalized potentials of Calderon's type, and consequently, their approximation properties can be studied independently in the framework of the difference potentials method by Ryaben'kii. The motivation for introducing and analyzing the discrete surface potentials was provided by the problems of active shielding and control of sound, in which the aforementioned source terms that drive the potentials are interpreted as the acoustic control sources that cancel out the unwanted noise on a predetermined region of interest.

  3. Thermal deformation of a large space panel caused by temperature difference between front and rear sides

    NASA Astrophysics Data System (ADS)

    Ichikawa, Naoki; Kurokawa, Haruhisa; Yajima, Nobuyuki; Kokaji, Shigeru; Suzuki, Akio

    This paper describes the development of a ground test system for determining the thermal deformation of large antenna panels to be used in space. The system is designed to measure the deformation occurring as a result of temperature differences between the front and rear surfaces of the panel. In the experimental set-up, a symmetric honeycomb panel was used. The front surface of the panel was heated by IR radiation, and the deformation was determined using a fringe scanning moire system which measured the shape of the rear surface. It was found that the temperature difference realized by the system was of the same order as was estimated on the orbit. The variations in the temperature difference were less than 15 percent of the average value. The effects of temperature distribution on the deformation were evaluated to be negligible by an FEM calculation.

  4. How large are uncertainties in future projection of reference evapotranspiration through different approaches?

    NASA Astrophysics Data System (ADS)

    Wang, Weiguang; Xing, Wanqiu; Shao, Quanxi

    2015-05-01

    As the indicator of atmospheric evaporative demand over a hypothetical reference surface, reference evapotranspiration (ET0) is an important input to hydrological models. Future projections of ET0 are of great importance in assessing the potential impacts of climate change on the hydrologic regime as well as water resources systems. Different estimating formulations and different input data reliabilities existing in practice determine there may be potential uncertainty in projection of future ET0 change. Here we investigated the difference of future ET0 response to climate change based on three approaches, i.e., more physically based Penman-Montieth equation with relatively uncertain downscaled data quality, more empirical temperature-based Hargreaves equation with more reliable downscaled input data, and statistical downscaling method with directly selecting ET0 as predictands. The Hanjiang River Basin, a headwater source of famous South to North Water Diversion Project (SNWDP) in China was chosen as example to illustrate this issue. Although similar increase processes of ET0 in the Hanjiang River Basin were suggested by three methods, the magnitude of ET0 increase differs substantially, indicating that uncertainty still exist despite of approximate performance of these methods in simulating general trends. Whilst increasing aridity index and decreasing water surplus over the period of 2011-2099 would inevitably cause negative impacts on the implementation of the SNWDP and effective adapting measures are thus expected.

  5. Large Eddy Simulation of Compressible Flow past an Oscillating Cylinder using the Spectral Difference Method

    NASA Astrophysics Data System (ADS)

    Cox, Christopher; Liang, Chunlei

    2011-11-01

    In this investigation, we implement a high-order three-dimensional spectral difference (SD) method to solve the compressible Navier-Stokes equations on an unstructured moving deformable grid. Presently, the SD method is used to perform simulations of compressible flow past an oscillating circular cylinder. Oscillations parallel and normal to the free stream are considered at a fixed Reynolds number of 4000, oscillation frequency of 1 Hz , and oscillation amplitude of 20% cylinder diameter. We extend this study to large eddy simulations with the integration of a Smagorinsky-type subgrid-scale (SGS) model. Computational results will be compared to experimental data. The effectiveness of the large eddy simulation in capturing the vortex dynamics in the wake is analyzed. This work is funded by the Mechanical & Aerospace Engineering Department at George Washington University

  6. Regulation of translational efficiency by different splice variants of the Disc large 1 oncosuppressor 5'-UTR.

    PubMed

    Cavatorta, Ana L; Facciuto, Florencia; Valdano, Marina Bugnon; Marziali, Federico; Giri, Adriana A; Banks, Lawrence; Gardiol, Daniela

    2011-07-01

    Human Disc large (DLG1) has been demonstrated to be involved in the control of cell polarity and maintenance of tissue architecture, and is frequently lost in human tumours. However, the mechanisms controlling DLG1 expression are poorly understood. To further examine the regulation of DLG1 expression, we analysed the 5' ends of DLG1 transcripts by rapid amplification of cDNA ends polymerase chain reaction. We identified an alternative splicing event in the 5' region of DLG1 mRNA that generates transcripts with two different 5' untranslated regions (5'-UTRs). We show by reporter assays that the DLG1 5'-UTR containing an alternatively spliced exon interferes with the translation of a downstream open reading frame (ORF). However, no significant differences in mRNA stability among the DLG1 5'-UTR variants were observed. Sequence analysis of the additional exon present in the larger DLG1 5'-UTR showed the presence of an upstream short ORF which is lost in the short version of the 5'-UTR DLG1. By mutagenesis and luciferase assays, we analysed the contribution of this upstream short ORF in reducing translation efficiency, and showed that its disruption can revert, to some extent, the negative regulation of large 5'-UTR. Using computational modelling we also show that the large DLG1 5'-UTR isoform forms a more stable structure than the short version, and this may contribute to its ability to repress translation. This represents the first analysis of the 5' region of the DLG1 transcripts and shows that differential expression of alternatively spliced 5'-UTRs with different translational properties could result in changes in DLG1 abundance. PMID:21595829

  7. Mirror energy differences at large isospin studied through direct two-nucleon knockout.

    PubMed

    Davies, P J; Bentley, M A; Henry, T W; Simpson, E C; Gade, A; Lenzi, S M; Baugher, T; Bazin, D; Berryman, J S; Bruce, A M; Diget, C Aa; Iwasaki, H; Lemasson, A; McDaniel, S; Napoli, D R; Ratkiewicz, A; Scruton, L; Shore, A; Stroberg, R; Tostevin, J A; Weisshaar, D; Wimmer, K; Winkler, R

    2013-08-16

    The first spectroscopy of excited states in 52Ni (T(z)=-2) and 51Co (T(z)=-3/2) has been obtained using the highly selective two-neutron knockout reaction. Mirror energy differences between isobaric analogue states in these nuclei and their mirror partners are interpreted in terms of isospin nonconserving effects. A comparison between large-scale shell-model calculations and data provides the most compelling evidence to date that both electromagnetic and an additional isospin nonconserving interactions for J=2 couplings, of unknown origin, are required to obtain good agreement. PMID:23992059

  8. Geo-structural modelling for potential large rock slide in Machu Picchu

    NASA Astrophysics Data System (ADS)

    Spizzichino, D.; Delmonaco, G.; Margottini, C.; Mazzoli, S.

    2009-04-01

    The monumental complex of the Historical Sanctuary of Machu Picchu, declared as World Heritage Site by UNESCO in 1983, is located in the Andean chain at approx. 80 km from Cuzco (Peru) and at an elevation of 2430 m a.s.l. along the Urubamba River Valley. From a geological point of view, the Machu Picchu granitoid pluton, forming part of the larger "Quillabamba granite", is one of a series of plutons intruded along the axial zone of the high Eastern Cordillera Permo-Liassic rift system including a variety of rock types, dominantly granites and granodiorites. The most evident structures at the outcrop scale consist of planar joint sets that may be variably reactivated and exhibiting 4 main orientations. At present, the site is affected by geological risk due to frequent landslides that threaten security and tourist exploitation. In the last years, the international landslide scientific community has promoted a multi-discipline joint programme mainly finalised to slope deformation monitoring and analysis after the warning, launched in 2001, of a potential collapse of the citadel, caused by a huge rock slide. The contribute of the Italian research team was devoted to implement a landslide risk analysis and an innovative remote sensing techniques. The main scope of this work is to present the implementation of a geo-structural modelling aimed at defining present and potential slope stability conditions of the Machu Picchu Citadel. Data have been collected by geological, structural and geomechanical field surveys and laboratory tests in order to reconstruct the geomorphological evolution of the area. Landslide types and evolution are strictly controlled by regional tectonic uplift and structural setting. Several slope instability phenomena have been identified and classified according to mechanism, material involved and state of activity. Rock falls, debris flows, rock slides and debris slides are the main surveyed landslide types. Rock slides and rock falls may produce blocks with dimensions variable from 10-1 to 102m3 that form the toe accumulation on steeper slopes. The area of the citadel has also been interpreted as affected by a deep mass movement (>100m) that, if confirmed by the present day monitoring systems, could be referred to a deep-seated gravitational slope deformation (DSGSD), probably of the type of the compound bi-planar sagging (CB) described by Hutchinson (1988). The analysis of active strain processes (e.g. tension cracks) along with the damage pattern surveyed on archaeological structures (e.g. sinking, swelling, tilting) suggest that the potential failure of a large rock slide may be located at a depth of ca. 30m. The various data sets have been integrated in order to obtain a general geo-structural and geotechnical model (strength and deformation parameters, seismic input) of the citadel at the slope scale. This represents a first step in implementing a slope stability analysis capable of reconstructing present and potential landslide evolution under static and dynamic conditions. This multi-discipline study, based on geological and structural analysis integrated with geotechnical and geomechanical interpretation, will aid defining actual landslide hazard and risk levels, indispensable for the design of low impact mitigation measures to be applied at Machu Picchu Citadel.

  9. Analysis of Potential for Titanium Liner Buckling after Proof in a Large Kevlar/Epoxy COPV

    NASA Technical Reports Server (NTRS)

    Phoenix, S. Leigh; Kezirian, Michael T.

    2009-01-01

    We analyze the potential for liner buckling in a 40-in Kevlar49/epoxy overwrapped spherical pressure vessel (COPV) due to long, local depressions or valleys in the titanium liner, which appeared after proof testing (autofrettage). We begin by presenting the geometric characteristics of approximately 20 mil (0.02 in.) deep depressions measured by laser profilometry in several vessels. While such depths were more typical, depths of more than 40 mils (0.02 in.) were seen near the equator in one particular vessel. Such depressions are largely the result of overlap of the edges of overwrap bands (with rectangular cross-section prepreg tows) from the first or second wrap patterns particularly where they start and end. We then discuss the physical mechanisms of formation of the depressions during the autofrettage process in terms of uneven void compaction in the overwrap around the tow overlap lines and the resulting 10-fold increase in through-thickness stiffness of the overwrap. We consider the effects of liner plastic yielding mechanisms in the liner on residual bending moments and interface pressures with the overwrap both at the peak proof pressure (approx.6500 psi) and when reducing the pressure to 0 psi. During depressurization the Bauschinger phenomenon becomes very important whereby extensive yielding in tension reduces the magnitude of the yield threshold in compression by 30 to 40%, compared to the virgin annealed state of the liner titanium. In the absence of a depression, the liner is elastically stable in compression even at liner overwrap interface pressures nominally 6 times the approx. 1000 psi interface pressure that exists at 0 psi. Using a model based on a plate-on-an-elastic-foundation, we develop an extensive analysis of the possible destabilizing effects of a frozen-in valley. The analysis treats the modifying effects of the residual bending moments and interface pressures remaining after the proof hold as well as the Bauschinger effect on the compressive yield threshold. The key result is that depression depths of up to 40 mils can be tolerated, but above 40 mils, the Bauschinger effect drives destabilization, and buckling becomes increasingly likely depending on the details of depression formation during autofrettage. It is almost certain that destabilization and buckling will occur for depression depths beyond 55 mils. The main equations and formulas for treating the various phases of depression development and potential buckling, are only briefly outlined in the paper, but are available from the authors.

  10. Prevalence of Potential Drug-Drug Interactions Involving Antiretroviral Drugs in a Large Kenyan Cohort

    PubMed Central

    Kigen, Gabriel; Kimaiyo, Sylvester; Nyandiko, Winstone; Faragher, Brian; Sang, Edwin; Jakait, Beatrice; Owen, Andrew; Back, David; Gibbons, Sara; Seden, Kay; Khoo, Saye H.

    2011-01-01

    Background Clinically significant drug-drug interactions (CSDIs) involving antiretrovirals are frequent and under-recognized in developed countries, but data are lacking for developing countries. Methodology and Principal Findings To investigate the prevalence of CSDIs between antiretrovirals and coadministered drugs, we surveyed prescriptions dispensed in a large HIV clinic in Kenya. Of 1040 consecutive patients screened, 996 were eligible for inclusion. CSDIs were defined as major (capable of causing severe or permanent damage, contraindicated, avoid or not recommended by the manufacturer, or requiring dose modification) or moderate (manufacturers advise caution, or close monitoring, or capable of causing clinical deterioration). A total of 334 patients (33.5%) were at risk for a CSDI, potentially lowering antiretroviral drug concentrations in 120 (12%) patients. Major interactions most frequently involved rifampicin (12.4%, mostly with efavirenz) and azoles (2.7%) whereas moderate interactions were frequently azoles (13%), steroids (11%), and antimalarials (3%). Multivariable analyses suggested that patients at risk for CSDIs had lower CD4 counts (P?=?0.006) and baseline weight (P?=?0.023) and WHO Stage 3 or 4 disease (P?0.007). Risk for CSDIs was not associated with particular regimens, although only 116 (11.6%) patients were receiving WHO second line regimens. Conclusions One in three patients receiving antiretrovirals in our programme were at risk of CSDIs. Strategies need to be urgently developed to avoid important drug interactions, to identify early markers of toxicity and to manage unavoidable interactions safely in order to reduce risk of harm, and to maximize the effectiveness of mass antiretroviral deployment in Africa. PMID:21373194

  11. Giant Aerosol Particles as a Potential Source of Supercooled Large Drops in Wintertime Stratiform Clouds

    NASA Astrophysics Data System (ADS)

    Lasher-Trapp, S.; Anderson-Bereznicki, S.; Twohy, C. H.

    2005-12-01

    Supercooled large drops (SLD) can pose a significant hazard for aviation because they tend to accumulate behind the leading edge of the wings where deicing mechanisms are lacking. Even when present in small amounts, SLD can cause significant ice buildup that degrades aircraft performance through decreased lift and increased drag. Multiple studies have demonstrated that warm rain processes are prevalent, or even dominant, in mixed-phase stratiform clouds containing SLD, but the formation mechanism for SLD has not been suitably demonstrated. We investigate the possibility that SLD form upon giant (diameter > 2m) aerosol particles, using observations collected with the National Center for Atmospheric Research's (NCAR) C130 aircraft during the second Alliance Icing Research Study (AIRSII). The observations are used to quantify and compare SLD in the clouds and giant aerosol particles in the clear air. Four of the six flights investigated have comparable numbers of SLD and giant aerosol particles; the other two flights have SLD concentrations several orders of magnitude less than the observed number of giant aerosol particles. No difference in the atmospheric or cloud conditions is found to explain the disparity in the results, but chemical analysis of collected giant aerosol particles reveals significant daily variability in their chemical composition. Surprisingly, the majority of giant aerosol particles collected on some flights were composed of salt. Backward air trajectories computed from the observation sites using numerical weather prediction model data suggest a local source of these giant salt particles rather than long-range transport from the oceans.

  12. Magnetic analytic bond-order potential for modeling the different phases of Mn at zero Kelvin

    NASA Astrophysics Data System (ADS)

    Drain, John F.; Drautz, Ralf; Pettifor, D. G.

    2014-04-01

    It is known that while group VII 4d Tc and 5d Re have hexagonally close-packed (hcp) ground states, 3d Mn adopts a complex ?-phase ground state, exhibiting complex noncollinear magnetic ordering. Density functional theory (DFT) calculations have shown that without magnetism, the ? phase is still the ground state of Mn implying that magnetism and the resultant atomic-size difference between large- and small-moment atoms are not the critical factors, as is commonly believed, in driving the anomalous stability of the ? phase over hcp. Using a canonical tight-binding (TB) model, it is found that for a more than half-filled d band, while harder potentials stabilize close-packed hcp, a softer potential stabilizes the more open ? phase. By analogy with the structural trend from open to close-packed phases down the group IV elements, the anomalous stability of the ? phase in Mn is shown to be due to 3d valent Mn lacking d states in the core which leads to an effectively softer atomic repulsion between the atoms than in 4d Tc and 5d Re. Subsequently, an analytic bond-order potential (BOP) is developed to investigate the structural and magnetic properties of elemental Mn at 0 K. It is derived within BOP theory directly from a new short-ranged orthogonal d-valent TB model of Mn, the parameters of which are fitted to reproduce the DFT binding energy curves of the four experimentally observed phases of Mn, namely, ?, ?, ?, ?, and ?-Mn. Not only does the BOP reproduce qualitatively the DFT binding energy curves of the five different structure types, it also predicts the complex collinear antiferromagnetic (AFM) ordering in ?-Mn, the ferrimagnetic ordering in ?-Mn, and the AFM ordering in ?-, ?-, and ?-Mn that are found by DFT. A BOP expansion including 14 moments is sufficiently converged to reproduce most of the properties of the TB model with the exception of the elastic shear constants, which require further moments. The current TB model, however, predicts values of the shear moduli and the vacancy formation energies that are approximately a factor of 2 too small, so that a future more realistic model for MD simulations will require these properties to be included from the outset in the fitting database.

  13. How does the foraging behavior of large herbivores cause different associational plant defenses?

    PubMed Central

    Huang, Yue; Wang, Ling; Wang, Deli; Zeng, De-Hui; Liu, Chen

    2016-01-01

    The attractant-decoy hypothesis predicts that focal plants can defend against herbivory by neighboring with preferred plant species when herbivores make decisions at the plant species scale. The repellent-plant hypothesis assumes that focal plants will gain protection by associating with nonpreferred neighbors when herbivores are selective at the patch scale. However, herbivores usually make foraging decisions at these scales simultaneously. The net outcomes of the focal plant vulnerability could depend on the spatial scale at which the magnitude of selectivity by the herbivores is stronger. We quantified and compared the within- and between-patch overall selectivity index (OSI) of sheep to examine the relationships between associational plant effects and herbivore foraging selectivity. We found that the sheep OSI was stronger at the within- than the between-patch scale, but focal plant vulnerability followed both hypotheses. Focal plants defended herbivory with preferred neighbors when the OSI difference between the two scales was large. Focal plants gained protection with nonpreferred neighbors when the OSI difference was narrowed. Therefore, the difference in selectivity by the herbivores between the relevant scales results in different associational plant defenses. Our study suggests important implications for understanding plant-herbivore interactions and grassland management. PMID:26847834

  14. Identification of flubendazole as potential anti-neuroblastoma compound in a large cell line screen

    PubMed Central

    Michaelis, Martin; Agha, Bishr; Rothweiler, Florian; Lschmann, Nadine; Voges, Yvonne; Mittelbronn, Michel; Starzetz, Tatjana; Harter, Patrick N.; Abhari, Behnaz A.; Fulda, Simone; Westermann, Frank; Riecken, Kristoffer; Spek, Silvia; Langer, Klaus; Wiese, Michael; Dirks, Wilhelm G.; Zehner, Richard; Cinatl, Jaroslav; Wass, Mark N.; Cinatl, Jindrich

    2015-01-01

    Flubendazole was shown to exert anti-leukaemia and anti-myeloma activity through inhibition of microtubule function. Here, flubendazole was tested for its effects on the viability of in total 461 cancer cell lines. Neuroblastoma was identified as highly flubendazole-sensitive cancer entity in a screen of 321 cell lines from 26 cancer entities. Flubendazole also reduced the viability of five primary neuroblastoma samples in nanomolar concentrations thought to be achievable in humans and inhibited vessel formation and neuroblastoma tumour growth in the chick chorioallantoic membrane assay. Resistance acquisition is a major problem in high-risk neuroblastoma. 119 cell lines from a panel of 140 neuroblastoma cell lines with acquired resistance to various anti-cancer drugs were sensitive to flubendazole in nanomolar concentrations. Tubulin-binding agent-resistant cell lines displayed the highest flubendazole IC50 and IC90 values but differences between drug classes did not reach statistical significance. Flubendazole induced p53-mediated apoptosis. The siRNA-mediated depletion of the p53 targets p21, BAX, or PUMA reduced the neuroblastoma cell sensitivity to flubendazole with PUMA depletion resulting in the most pronounced effects. The MDM2 inhibitor and p53 activator nutlin-3 increased flubendazole efficacy while RNAi-mediated p53-depletion reduced its activity. In conclusion, flubendazole represents a potential treatment option for neuroblastoma including therapy-refractory cells. PMID:25644037

  15. Different Anaphoric Expressions Are Investigated by Event-Related Brain Potentials

    ERIC Educational Resources Information Center

    Streb, Judith; Hennighausen, Erwin; Rosler, Frank

    2004-01-01

    Event-related potentials were recorded to substantiate the claim of a distinct psycholinguistic status of (a) pronouns vs. proper names and (b) ellipses vs. proper names. In two studies 41 students read sentences in which the number of intervening words between the anaphor and its antecedent was either small or large. Comparing the far with the

  16. Using a High-Resolution Global Climate Model to Simulate Extratropical Cyclones with Large Storm Surge Potential

    NASA Astrophysics Data System (ADS)

    Alpert, A. J.; Broccoli, A. J.; Kapnick, S. B.

    2014-12-01

    The storm surge caused by Hurricane Sandy triggered a need for new research on surge inundation and associated risk. However, observational records of coastal water levels are limited, which increases uncertainty in risk analysis. Global climate models provide a means of simulating a much larger sample of potential surge-producing events, allowing for better resolution of the tail of the frequency distribution. The resolution of current climate models may be sufficient to simulate the structure and intensity of extratropical cyclones. Since 17 of the 20 greatest storm surge events at The Battery in New York City occurred in association with extratropical cyclones, we examine the ability of a coupled atmosphere-ocean general circulation model with 50 km atmospheric resolution (the GFDL CM2.5 model) to realistically simulate extratropical cyclones in the western North Atlantic Ocean that are capable of producing large storm surges. We analyze the similarities between CM2.5 and reanalysis products, including NASA's MERRA (Modern-Era Retrospective analysis for Research and Applications). After considering differences in spatial and temporal resolution, preliminary analyses suggest that indicators of cyclone strength in CM2.5 and MERRA are comparable. We also investigate a simple screening method based on wind speed and direction to identify potential surge-producing events in CM2.5 for determining a subset of events for more detailed analysis.

  17. Large differences in land use emission quantifications implied by definition discrepancies

    NASA Astrophysics Data System (ADS)

    Stocker, B. D.; Joos, F.

    2015-03-01

    The quantification of CO2 emissions from anthropogenic land use and land use change (eLUC) is essential to understand the drivers of the atmospheric CO2 increase and to inform climate change mitigation policy. Reported values in synthesis reports are commonly derived from different approaches (observation-driven bookkeeping and process-modelling) but recent work has emphasized that inconsistencies between methods may imply substantial differences in eLUC estimates. However, a consistent quantification is lacking and no concise modelling protocol for the separation of primary and secondary components of eLUC has been established. Here, we review the conceptual differences of eLUC quantification methods and apply an Earth System Model to demonstrate that what is claimed to represent total eLUC differs by up to ~20% when quantified from ESM vs. offline vegetation models. Under a future business-as-usual scenario, differences tend to increase further due to slowing land conversion rates and an increasing impact of altered environmental conditions on land-atmosphere fluxes. We establish how coupled Earth System Models may be applied to separate component fluxes of eLUC arising from the replacement of potential C sinks/sources and the land use feedback and show that secondary fluxes derived from offline vegetation models are conceptually and quantitatively not identical to either, nor their sum. Therefore, we argue that synthesis studies and global carbon budget accountings should resort to the "least common denominator" of different methods, following the bookkeeping approach where only primary land use emissions are quantified under the assumption of constant environmental boundary conditions.

  18. Evaluation of different calibration strategies for large scale continuous hydrological modelling

    NASA Astrophysics Data System (ADS)

    Wallner, M.; Haberlandt, U.; Dietrich, J.

    2012-09-01

    For the analysis of climate impact on flood flows and flood frequency in macroscale river basins, hydrological models can be forced by several sets of hourly long-term climate time series. Considering the large number of model units, the small time step and the required recalibrations for different model forcing an efficient calibration strategy and optimisation algorithm are essential. This study investigates the impact of different calibration strategies and different optimisation algorithms on the performance and robustness of a semi-distributed model. The different calibration strategies were (a) Lumped, (b) 1-Factor, (c) Distributed and (d) Regionalisation. The latter uses catchment characteristics and estimates parameter values via transfer functions. These methods were applied in combination with three different optimisation algorithms: PEST, DDS, and SCE. In addition to the standard temporal evaluation of the calibration strategies, a spatial evaluation was applied. This was done by transferring the parameters from calibrated catchments to uncalibrated ones and validating the model performance of these uncalibrated catchments. The study was carried out for five sub-catchments of the Aller-Leine River Basin in Northern Germany. The best result for temporal evaluation was achieved by using the combination of the DDS optimisation with the Distributed strategy. The Regionalisation method obtained the weakest performance for temporal evaluation. However, for spatial evaluation the Regionalisation indicated more robust models, closely followed by the Lumped method. The 1-Factor and the Distributed strategy showed clear disadvantages regarding spatial parameter transferability. For the parameter estimation based on catchment descriptors as required for ungauged basins, the Regionalisation strategy seems to be a promising tool particularly in climate impact analysis and for hydrological modelling in general.

  19. Sex Differences on "g" and Non-"g" Intellectual Performance Reveal Potential Sources of STEM Discrepancies

    ERIC Educational Resources Information Center

    Lemos, Gina C.; Abad, Francisco J.; Almeida, Leandro S.; Colom, Roberto

    2013-01-01

    The analysis of sex differences in cognitive abilities is largely confusing because these differences are masked by the pervasive influence of the general factor of intelligence (g). In this study a battery of five reasoning tests (abstract [AR], numerical [NR], verbal [VR], mechanical [MR], and spatial [SR]) was completed by a sample of 3233…

  20. Sex Differences on "g" and Non-"g" Intellectual Performance Reveal Potential Sources of STEM Discrepancies

    ERIC Educational Resources Information Center

    Lemos, Gina C.; Abad, Francisco J.; Almeida, Leandro S.; Colom, Roberto

    2013-01-01

    The analysis of sex differences in cognitive abilities is largely confusing because these differences are masked by the pervasive influence of the general factor of intelligence (g). In this study a battery of five reasoning tests (abstract [AR], numerical [NR], verbal [VR], mechanical [MR], and spatial [SR]) was completed by a sample of 3233

  1. Comparison of different hand-drying methods: the potential for airborne microbe dispersal and contamination.

    PubMed

    Best, E L; Redway, K

    2015-03-01

    Efficient washing and drying of hands is important in prevention of the transfer of micro-organisms. However, knowledge surrounding the potential for microbial contamination according to hand-drying methods is limited. This study assessed the potential for airborne microbe dispersal during hand drying by four methods (paper towels, roller towel, warm air and jet air dryer) using three different models. The jet air dryer dispersed liquid from users' hands further and over a greater range (up to 1.5m) than the other drying methods (up to 0.75 m), demonstrating the differing potential risks for airborne microbe dissemination, particularly if handwashing is suboptimal. PMID:25586988

  2. Time difference of arrival to blast localization of potential chemical/biological event on the move

    NASA Astrophysics Data System (ADS)

    Morcos, Amir; Desai, Sachi; Peltzer, Brian; Hohil, Myron E.

    2007-10-01

    Integrating a sensor suite with ability to discriminate potential Chemical/Biological (CB) events from high-explosive (HE) events employing a standalone acoustic sensor with a Time Difference of Arrival (TDOA) algorithm we developed a cueing mechanism for more power intensive and range limited sensing techniques. Enabling the event detection algorithm to locate to a blast event using TDOA we then provide further information of the event as either Launch/Impact and if CB/HE. The added information is provided to a range limited chemical sensing system that exploits spectroscopy to determine the contents of the chemical event. The main innovation within this sensor suite is the system will provide this information on the move while the chemical sensor will have adequate time to determine the contents of the event from a safe stand-off distance. The CB/HE discrimination algorithm exploits acoustic sensors to provide early detection and identification of CB attacks. Distinct characteristics arise within the different airburst signatures because HE warheads emphasize concussive and shrapnel effects, while CB warheads are designed to disperse their contents over large areas, therefore employing a slower burning, less intense explosive to mix and spread their contents. Differences characterized by variations in the corresponding peak pressure and rise time of the blast, differences in the ratio of positive pressure amplitude to the negative amplitude, and variations in the overall duration of the resulting waveform. The discrete wavelet transform (DWT) is used to extract the predominant components of these characteristics from air burst signatures at ranges exceeding 3km. Highly reliable discrimination is achieved with a feed-forward neural network classifier trained on a feature space derived from the distribution of wavelet coefficients and higher frequency details found within different levels of the multiresolution decomposition. The development of an adaptive noise floor to provide early event detection assists in minimizing the false alarm rate and increasing the confidence whether the event is blast event or back ground noise. The integration of these algorithms with the TDOA algorithm provides a complex suite of algorithms that can give early warning detection and highly reliable look direction from a great stand-off distance for a moving vehicle to determine if a candidate blast event is CB and if CB what is the composition of the resulting cloud.

  3. Zeta potentials of polydimethylsiloxane surfaces modified by polybrene of different concentrations.

    PubMed

    Song, Yongxin; Li, Jun; Li, Dongqing

    2016-02-01

    Zeta potential is an important parameter for characterizing the electrokinetic properties of a solid-liquid interface. In this paper, zeta potentials of polydimethylsiloxane surfaces modified by polybrene (PB) solutions of different concentrations in Phosphate buffer solution and pure water were reported. The zeta potentials were measured by an induction current method. The measurements were validated both by a calibration curve based on the data reported in the published papers and by comparing the zeta potential determined by using the Smoluchowski equation and the measured velocity of the electrokinetic motion of particles in a microchannel. PMID:26634306

  4. An SPH model for multiphase flows with complex interfaces and large density differences

    NASA Astrophysics Data System (ADS)

    Chen, Z.; Zong, Z.; Liu, M. B.; Zou, L.; Li, H. T.; Shu, C.

    2015-02-01

    In this paper, an improved SPH model for multiphase flows with complex interfaces and large density differences is developed. The multiphase SPH model is based on the assumption of pressure continuity over the interfaces and avoids directly using the information of neighboring particles' densities or masses in solving governing equations. In order to improve computational accuracy and to obtain smooth pressure fields, a corrected density re-initialization is applied. A coupled dynamic solid boundary treatment (SBT) is implemented both to reduce numerical oscillations and to prevent unphysical particle penetration in the boundary area. The density correction and coupled dynamics SBT algorithms are modified to adapt to the density discontinuity on fluid interfaces in multiphase simulation. A cut-off value of the particle density is set to avoid negative pressure, which can lead to severe numerical difficulties and may even terminate the simulations. Three representative numerical examples, including a Rayleigh-Taylor instability test, a non-Boussinesq problem and a dam breaking simulation, are presented and compared with analytical results or experimental data. It is demonstrated that the present SPH model is capable of modeling complex multiphase flows with large interfacial deformations and density ratios.

  5. Prediction model of potential hepatocarcinogenicity of rat hepatocarcinogens using a large-scale toxicogenomics database

    SciTech Connect

    Uehara, Takeki; Minowa, Yohsuke; Morikawa, Yuji; Kondo, Chiaki; Maruyama, Toshiyuki; Kato, Ikuo; Nakatsu, Noriyuki; Igarashi, Yoshinobu; Ono, Atsushi; Hayashi, Hitomi; Mitsumori, Kunitoshi; Yamada, Hiroshi; Ohno, Yasuo; Urushidani, Tetsuro

    2011-09-15

    The present study was performed to develop a robust gene-based prediction model for early assessment of potential hepatocarcinogenicity of chemicals in rats by using our toxicogenomics database, TG-GATEs (Genomics-Assisted Toxicity Evaluation System developed by the Toxicogenomics Project in Japan). The positive training set consisted of high- or middle-dose groups that received 6 different non-genotoxic hepatocarcinogens during a 28-day period. The negative training set consisted of high- or middle-dose groups of 54 non-carcinogens. Support vector machine combined with wrapper-type gene selection algorithms was used for modeling. Consequently, our best classifier yielded prediction accuracies for hepatocarcinogenicity of 99% sensitivity and 97% specificity in the training data set, and false positive prediction was almost completely eliminated. Pathway analysis of feature genes revealed that the mitogen-activated protein kinase p38- and phosphatidylinositol-3-kinase-centered interactome and the v-myc myelocytomatosis viral oncogene homolog-centered interactome were the 2 most significant networks. The usefulness and robustness of our predictor were further confirmed in an independent validation data set obtained from the public database. Interestingly, similar positive predictions were obtained in several genotoxic hepatocarcinogens as well as non-genotoxic hepatocarcinogens. These results indicate that the expression profiles of our newly selected candidate biomarker genes might be common characteristics in the early stage of carcinogenesis for both genotoxic and non-genotoxic carcinogens in the rat liver. Our toxicogenomic model might be useful for the prospective screening of hepatocarcinogenicity of compounds and prioritization of compounds for carcinogenicity testing. - Highlights: >We developed a toxicogenomic model to predict hepatocarcinogenicity of chemicals. >The optimized model consisting of 9 probes had 99% sensitivity and 97% specificity. >This model enables us to detect genotoxic as well as non-genotoxic hepatocarcinogens.

  6. When species' ranges meet: assessing differences in habitat selection between sympatric large carnivores.

    PubMed

    Rauset, Geir Rune; Mattisson, Jenny; Andrn, Henrik; Chapron, Guillaume; Persson, Jens

    2013-07-01

    Differentiation in habitat selection among sympatric species may depend on niche partitioning, species interactions, selection mechanisms and scales considered. In a mountainous area in Sweden, we explored hierarchical habitat selection in Global Positioning System-collared individuals of two sympatric large carnivore species; an obligate predator, the Eurasian lynx (Lynx lynx), and a generalist predator and scavenger, the wolverine (Gulo gulo). Although the species' fundamental niches differ widely, their ranges overlap in this area where they share a prey base and main cause of mortality. Both lynx and wolverines selected for steep and rugged terrain in mountainous birch forest and in heaths independent of scale and available habitats. However, the selection of lynx for their preferred habitats was stronger when they were forming home ranges and they selected the same habitats within their home ranges independent of home range composition. Wolverines displayed a greater variability when selecting home ranges and habitat selection also varied with home range composition. Both species selected for habitats that promote survival through limited encounters with humans, but which also are rich in prey, and selection for these habitats was accordingly stronger in winter when human activity was high and prey density was low. We suggest that the observed differences between the species result primarily from different foraging strategies, but may also depend on differences in ranging and resting behaviour, home range size, and relative density of each species. Our results support the prediction that sympatric carnivores with otherwise diverging niches can select for the same resources when sharing main sources of food and mortality. PMID:23242426

  7. Location, location, location: small shifts in collection site result in large intraspecific differences in macroalgal palatability

    NASA Astrophysics Data System (ADS)

    Keeley, Kathryn N.; Stroh, Jolie D.; Tran, Diem Samantha C.; Fong, Caitlin R.; Fong, Peggy

    2015-06-01

    The role of herbivorous fishes in coral reef resilience has increased interest in the process of herbivory and has focused attention on herbivore feeding behavior, making it important to evaluate experimental methods used to assess herbivore decisions. We tested whether small-scale differences in collection site play a role in within-species palatability of macroalgae. Baseline grazing assays using algae collected on a fringing reef in Moorea, French Polynesia, revealed that herbivore preferences among three common species ranked Padina boryana > Sargassum mangarevense ? Amansia rhodantha. Comparing grazing preferences between individual thalli of the same species collected <15 m apart revealed that consumption of intertidal S. mangarevense was nearly six times greater than for conspecifics collected from the adjacent subtidal reef flat. The same trend occurred for P. boryana but was not significant. This demonstrated that algal palatability can vary on a very small spatial scale, presenting a potential trap for the unwary when setting up experiments; we encourage researchers to consider this potential complication in experimental studies of herbivory.

  8. Gender Differences in Memory Processing: Evidence from Event-Related Potentials to Faces

    ERIC Educational Resources Information Center

    Guillem, F.; Mograss, M.

    2005-01-01

    This study investigated gender differences on memory processing using event-related potentials (ERPs). Behavioral data and ERPs were recorded in 16 males and 10 females during a recognition memory task for faces. The behavioral data results showed that females performed better than males. Gender differences on ERPs were evidenced over anterior…

  9. An implicit high-order spectral difference approach for large eddy simulation

    NASA Astrophysics Data System (ADS)

    Parsani, M.; Ghorbaniasl, G.; Lacor, C.; Turkel, E.

    2010-08-01

    The filtered fluid dynamic equations are discretized in space by a high-order spectral difference (SD) method coupled with large eddy simulation (LES) approach. The subgrid-scale stress tensor is modelled by the wall-adapting local eddy-viscosity model (WALE). We solve the unsteady equations by advancing in time using a second-order backward difference formulae (BDF2) scheme. The nonlinear algebraic system arising from the time discretization is solved with the nonlinear lower-upper symmetric Gauss-Seidel (LU-SGS) algorithm. In order to study the sensitivity of the method, first, the implicit solver is used to compute the two-dimensional (2D) laminar flow around a NACA0012 airfoil at Re = 5 10 5 with zero angle of attack. Afterwards, the accuracy and the reliability of the solver are tested by solving the 2D "turbulent" flow around a square cylinder at Re = 10 4 and Re = 2.2 10 4. The results show a good agreement with the experimental data and the reference solutions.

  10. Modelling nitrogen retention in floodplains with different degrees of degradation for three large rivers in Germany.

    PubMed

    Natho, S; Venohr, M; Henle, K; Schulz-Zunkel, C

    2013-06-15

    Floodplains perform a variety of ecosystem functions and services - more than many other ecosystems. One of these ecosystem services is the reduction in nitrogen (N) loads and a subsequent improvement to the water quality. Since diffuse and also point nitrogen sources continue to cause a variety of problems in rivers and floodplains, inundated floodplains could act as net sinks for N and are therefore of great importance throughout Germany and Europe. This study analyses the effects of riparian floodplains on N-retention on the landscape scale for three large river systems with different degrees of degradation. Two approaches, differing in terms of the complexity of their respective input data and methods, were applied under wet and dry conditions. Whereas the proxy-based approach considers proxy values for N-retention, the model-based approach accounts for event-driven dynamic input data such as the extent of the inundated floodplain and incoming loads. Comparing the results of the two approaches it can be observed that floodplains of the near-natural river can retain up to 4% of the river load under wet conditions. During such conditions N-retention in floodplains is similar to that of rivers. For the two other floodplains, the results of the two approaches were quite different, showing lower N-retention capacities. However, for these floodplains as well, both approaches are suitable for calculating measurable N-retention rates, which is an important result because it also suggests that even degraded floodplains still preserve this particular ecosystem function and therefore still contribute to improving the quality of river water. PMID:23545402

  11. Differences in ichthyofauna feeding habits among lateral lagoons and the river channel in a large reservoir.

    PubMed

    Ferrareze, M; Nogueira, M G; Casatti, L

    2015-05-01

    In this study, we investigated differences in feeding habits of small-sized ichthyofauna among lateral lagoons and the river channel in a large reservoir. The study was performed in four lagoons and in one sampling site of the main channel in Rosana Reservoir, Paranapanema River, Brazil. The samples were taken in September and November of 2004 and in January, March, May, and August of 2005. Fish were sampled with a 7.5 m2 hand net. Five manual throws were made toward aquatic macrophytes stands. The sampling design favored the collection of small-sized fish fauna (juveniles/small-sized species). The stomach contents of 42 species were analyzed. A total of 183 different items were consumed by fish. These items were grouped in 11 food categories, which were used to classify fish into seven trophic guilds. Aquatic insects were consumed by 32 species and were the predominant feeding item. In the river, the most consumed items were aquatic insects, cladocerans, and phytoplankton, whereas in the lagoons aquatic insects, copepods, and cladocerans were the main items. By comparing each trophic guild, the number of insectivores, algivores, and zooplanktivores species was higher in the lagoons than in the river, and the opposite was found only for omnivore fish. Low niche width in all sites indicates high trophic specialization and low niche overlap between pairs of species. Fish assemblage in the lateral lagoons presents feeding habits distinct from those of the river species, indicating that the coexistence and high abundance of small-sized fish in the sampling sites are explained by their high feeding adaptability, which includes a tendency toward dietary specialization, low feeding overlap, and resource partitioning, along with different temporal resource uses. PMID:26132022

  12. Prioritization of pharmaceuticals for potential environmental hazard through leveraging a large scale mammalian pharmacological dataset

    EPA Science Inventory

    To proceed in the investigation of potential effects of thousands of active pharmaceutical ingredients (API) which may enter the aquatic environment, a cohesive research strategy, specifically a prioritization is paramount. API are biologically active, with specific physiologica...

  13. Leveraging a large scale mammalian pharmacological dataset to prioritize potential environmental hazard of pharmaceuticals

    EPA Science Inventory

    The potential for pharmaceuticals in the environment to cause adverse ecological effects is of increasing concern. Given the thousands of active pharmaceutical ingredients (APIs) which can enter the aquatic environment through various means, a current challenge in aquatic toxicol...

  14. Potential of mean force of association of large hydrophobic particles: toward the nanoscale limit.

    PubMed

    Makowski, Mariusz; Czaplewski, Cezary; Liwo, Adam; Scheraga, Harold A

    2010-01-21

    The potentials of mean force (PMFs) were determined, in both water with the TIP3P water model and in vacuo, for systems involving formation of nonpolar dimers composed of bicyclooctane, adamantane (both an all-atom model and a sphere with the radius of 3.4 A representing adamantane), and fullerene, respectively. A series of umbrella-sampling molecular dynamics simulations with the AMBER force field were carried out for each pair under both environmental conditions. The PMFs were calculated by using the weighted histogram analysis method. The results were compared with our previously determined PMF for neopentane. The shape of the PMFs for dimers of all four nonpolar molecules is characteristic of hydrophobic interactions with contact and solvent-separated minima and desolvation maxima. The positions of all these minima and maxima change with the size of the nonpolar molecule; for larger molecules they shift toward larger distances. Comparison of the PMFs of the bicyclooctane, adamantane, and fullerene dimers in water and in vacuo shows that hydrophobic interactions in each dimer are different from that for the dimer of neopentane. Interactions in the bicyclooctane, adamantane, and fullerene dimers are stronger in vacuo than in water. These dimers cannot be treated as classical, spherical, hydrophobic objects. The solvent contribution to the PMF was also computed by subtracting the PMF determined in vacuo from that in explicit solvent. The solvent contribution to the PMFs of bicyclooctane, adamantane, and fullerene is positive, as opposed to that of neopentane. The water molecules in the first solvation sphere of both adamantane and neopentane dimers are more ordered as compared to bulk water, with their dipole moments pointing away from the surface of the dimers. The average number of hydrogen bonds per water molecule in the first hydration shell of adamantane is smaller compared to that in bulk water, but this shell is thicker for all-atom adamantane than for neopentane or a spherical model of adamantane. In the second hydration shell, the average number of hydrogen bonds is greater compared to that in bulk water only for neopentane and a spherical model of adamantane but not for the all-atom model. The strength of the hydrophobic interactions shows a linear dependence on the number of carbon atoms both in water and in vacuo. Smaller nonpolar particles interact more strongly in water than in vacuo. For larger molecules, such as bicyclooctane, adamantane and fullerene, the reversed tendency is observed. PMID:20039620

  15. Tree Species Linked to Large Differences in Ecosystem Carbon Distribution in the Boreal Forest of Alaska

    NASA Astrophysics Data System (ADS)

    Melvin, A. M.; Mack, M. C.; Johnstone, J. F.; Schuur, E. A. G.; Genet, H.; McGuire, A. D.

    2014-12-01

    In the boreal forest of Alaska, increased fire severity associated with climate change is altering plant-soil-microbial feedbacks and ecosystem carbon (C) dynamics. The boreal landscape has historically been dominated by black spruce (Picea mariana), a tree species associated with slow C turnover and large soil organic matter (SOM) accumulation. Historically, low severity fires have led to black spruce regeneration post-fire, thereby maintaining slow C cycling rates and large SOM pools. In recent decades however, an increase in high severity fires has led to greater consumption of the soil organic layer (SOL) during fire and subsequent establishment of deciduous tree species in areas previously dominated by black spruce. This shift to a more deciduous dominated landscape has many implications for ecosystem structure and function, as well as feedbacks to global C cycling. To improve our understanding of how boreal tree species affect C cycling, we quantified above- and belowground C stocks and fluxes in adjacent, mid-successional stands of black spruce and Alaska paper birch (Betula neoalaskana) that established following a 1958 fire near Fairbanks, Alaska. Although total ecosystem C pools (aboveground live tree biomass + dead wood + SOL + top 10 cm of mineral soil) were similar for the two stand types, the distribution of C among pools was markedly different. In black spruce, 78% of measured C was found in soil pools, primarily in the SOL, where spruce contained twice the C stored in paper birch (4.8 0.3 vs. 2.4 0.1 kg C m-2). In contrast, aboveground biomass dominated ecosystem C pools in birch forest (6.0 0.3 vs. 2.5 0.2 kg C m-2 in birch and spruce, respectively). Our findings suggest that tree species exert a strong influence over plant-soil-microbial feedbacks and may have long-term effects on ecosystem C sequestration and storage that feedback to the climate system.

  16. Large Deformation Mechanisms, Plasticity, and Failure of an Individual Collagen Fibril With Different Mineral Content.

    PubMed

    Depalle, Baptiste; Qin, Zhao; Shefelbine, Sandra J; Buehler, Markus J

    2016-02-01

    Mineralized collagen fibrils are composed of tropocollagen molecules and mineral crystals derived from hydroxyapatite to form a composite material that combines optimal properties of both constituents and exhibits incredible strength and toughness. Their complex hierarchical structure allows collagen fibrils to sustain large deformation without breaking. In this study, we report a mesoscale model of a single mineralized collagen fibril using a bottom-up approach. By conserving the three-dimensional structure and the entanglement of the molecules, we were able to construct finite-size fibril models that allowed us to explore the deformation mechanisms which govern their mechanical behavior under large deformation. We investigated the tensile behavior of a single collagen fibril with various intrafibrillar mineral content and found that a mineralized collagen fibril can present up to five different deformation mechanisms to dissipate energy. These mechanisms include molecular uncoiling, molecular stretching, mineral/collagen sliding, molecular slippage, and crystal dissociation. By multiplying its sources of energy dissipation and deformation mechanisms, a collagen fibril can reach impressive strength and toughness. Adding mineral into the collagen fibril can increase its strength up to 10 times and its toughness up to 35 times. Combining crosslinks with mineral makes the fibril stiffer but more brittle. We also found that a mineralized fibril reaches its maximum toughness to density and strength to density ratios for a mineral density of around 30%. This result, in good agreement with experimental observations, attests that bone tissue is optimized mechanically to remain lightweight but maintain strength and toughness. 2015 American Society for Bone and Mineral Research. PMID:26866939

  17. Anaerobic treatability and biogas production potential studies of different agro-industrial wastewaters in Turkey.

    PubMed

    Demirer, G N; Duran, M; Ergder, T H; Gven, E; Ugurlu, O; Tezel, U

    2000-01-01

    The anaerobic treatability and methane generation potential of the wastewaters of the three important agro-industries in Turkey, namely, cheese-making, poultry breeding and the olive-oil mill industries were studied. Biochemical methane potential (BMP) experiments were conducted for different initial chemical oxygen demand (COD) concentrations. The results indicate that anaerobic treatment was possible for all the wastewaters studied and the biogas produced had a high methane content. PMID:11587444

  18. Differences between the deformed-potential and folding-model descriptions of inelastic nuclear scattering

    SciTech Connect

    Hnizdo, V. )

    1994-08-01

    The differences between the deformed-potential and folding-model descriptions of inelastic nuclear scattering, attention to which has been called recently by Beene, Horen, and Satchler [Phys. Rev. C 48, 3128 (1993)], were pointed out already some time ago by contrasting the rules of equal deformation lengths and equal normalized multipole moments for the optical potential and the underlying nucleon distribution of the excited nucleus.

  19. Large-Eddy Simulations of Wind Turbine Wakes Subject to Different Atmospheric Stabilities

    NASA Astrophysics Data System (ADS)

    Churchfield, M.; Lundquist, J. K.; Lee, S.; Clifton, A.

    2014-12-01

    As a byproduct of energy extraction, wind turbines create a low-speed, turbulent wake that propagate downwind. When wind turbines are situated in a group, as in a wind plant, the interactions of these wakes with other turbines are important because wake effects decrease the efficiency of the wind plant, and they increase mechanical loads on individual turbines. Wakes propagate downstream differently depending on the inflow conditions, and these conditions are heavily dominated by atmospheric stability. For example, we know that wakes are more persistent in stable conditions than in unstable conditions. Also, stable conditions often have significant wind veer which skews wakes laterally. Different levels of turbulence intensity are associated with different atmospheric stability levels, and turbulence intensity acts to diffuse wakes and to cause wake meandering. Wake physics are complex, and to understand them better, a high-resolution representation of the flow is necessary. Measurements are difficult with current sensing equipment because of the sheer size of wakes and the unsteady atmospheric environment in which they are found. Numerical simulations complement measurements and provide a high-resolution representation of the entire three-dimensional, unsteady flow field. In this work, we use large-eddy simulation (LES), the highest fidelity type of computational fluid dynamics (CFD) feasible for high-Reynolds-number wake flow. LES directly resolves the larger, energy-containing turbulent scales and models the effects of the subgrid scales that the computational mesh cannot resolve. Our solver is based on the OpenFOAM open-source CFD toolbox. Turbines are modeled using rotating actuator lines. Here, we present our LES of the wake behind a modern 1.5 MW turbine subject to different inflow atmospheric stability. We will present results of wakes subject to stable (strongly and weakly stable), neutral, and unstable conditions. We are particularly interested in how stability affects wake recovery, wake skewing, and wake meandering. Figure 1 shows horizontal slices of instantaneous contours of vorticity magnitude in the computed wake of a turbine subject to weakly stable atmospheric inflow. A multi-resolution mesh is used with the finest region of 1.25 m resolution surrounding the turbine and the wake.

  20. Parametric Evaluation of Large-Scale High-Temperature Electrolysis Hydrogen Production Using Different Advanced Nuclear Reactor Heat Sources

    SciTech Connect

    Edwin A. Harvego; Michael G. McKellar; James E. O'Brien; J. Stephen Herring

    2009-09-01

    High Temperature Electrolysis (HTE), when coupled to an advanced nuclear reactor capable of operating at reactor outlet temperatures of 800 C to 950 C, has the potential to efficiently produce the large quantities of hydrogen needed to meet future energy and transportation needs. To evaluate the potential benefits of nuclear-driven hydrogen production, the UniSim process analysis software was used to evaluate different reactor concepts coupled to a reference HTE process design concept. The reference HTE concept included an Intermediate Heat Exchanger and intermediate helium loop to separate the reactor primary system from the HTE process loops and additional heat exchangers to transfer reactor heat from the intermediate loop to the HTE process loops. The two process loops consisted of the water/steam loop feeding the cathode side of a HTE electrolysis stack, and the sweep gas loop used to remove oxygen from the anode side. The UniSim model of the process loops included pumps to circulate the working fluids and heat exchangers to recover heat from the oxygen and hydrogen product streams to improve the overall hydrogen production efficiencies. The reference HTE process loop model was coupled to separate UniSim models developed for three different advanced reactor concepts (a high-temperature helium cooled reactor concept and two different supercritical CO2 reactor concepts). Sensitivity studies were then performed to evaluate the affect of reactor outlet temperature on the power cycle efficiency and overall hydrogen production efficiency for each of the reactor power cycles. The results of these sensitivity studies showed that overall power cycle and hydrogen production efficiencies increased with reactor outlet temperature, but the power cycles producing the highest efficiencies varied depending on the temperature range considered.

  1. Identification of large-scale human-specific copy number differences by inter-species array comparative genomic hybridization.

    PubMed

    Goidts, Violaine; Armengol, Lluis; Schempp, Werner; Conroy, Jeffrey; Nowak, Norma; Müller, Stefan; Cooper, David N; Estivill, Xavier; Enard, Wolfgang; Szamalek, Justyna M; Hameister, Horst; Kehrer-Sawatzki, Hildegard

    2006-03-01

    Copy number differences (CNDs), and the concomitant differences in gene number, have contributed significantly to the genomic divergence between humans and other primates. To assess its relative importance, the genomes of human, common chimpanzee, bonobo, gorilla, orangutan and macaque were compared by comparative genomic hybridization using a high-resolution human BAC array (aCGH). In an attempt to avoid potential interference from frequent intra-species polymorphism, pooled DNA samples were used from each species. A total of 322 sites of large-scale inter-species CND were identified. Most CNDs were lineage-specific but frequencies differed considerably between the lineages; the highest CND frequency among hominoids was observed in gorilla. The conserved nature of the orangutan genome has already been noted by karyotypic studies and our findings suggest that this degree of conservation may extend to the sub-microscopic level. Of the 322 CND sites identified, 14 human lineage-specific gains were observed. Most of these human-specific copy number gains span regions previously identified as segmental duplications (SDs) and our study demonstrates that SDs are major sites of CND between the genomes of humans and other primates. Four of the human-specific CNDs detected by aCGH map close to the breakpoints of human-specific karyotypic changes [e.g., the human-specific inversion of chromosome 1 and the polymorphic inversion inv(2)(p11.2q13)], suggesting that human-specific duplications may have predisposed to chromosomal rearrangement. The association of human-specific copy number gains with chromosomal breakpoints emphasizes their potential importance in mediating karyotypic evolution as well as in promoting human genomic diversity. PMID:16395594

  2. Interactions between large and small subunits of different acetohydroxyacid synthase isozymes of Escherichia coli.

    PubMed

    Vyazmensky, Maria; Zherdev, Yuri; Slutzker, Alex; Belenky, Inna; Kryukov, Olga; Barak, Ze'ev; Chipman, David M

    2009-09-15

    The large, catalytic subunits (LSUs; ilvB, ilvG and ilvI, respectively) of enterobacterial acetohydroxyacid synthases isozymes (AHAS I, II and III) have molecular weights approximately 60 kDa and are paralogous with a family of other thiamin diphosphate dependent enzymes. The small, regulatory subunits (SSUs) of AHAS I and AHAS III (ilvN and ilvH) are required for valine inhibition, but ilvN and ilvH can only confer valine sensitivity on their own LSUs. AHAS II is valine resistant. The LSUs have only approximately 15, <1 and approximately 3%, respectively, of the activity of their respective holoenzymes, but the holoenzymes can be reconstituted with complete recovery of activity. We have examined the activation of each of the LSUs by SSUs from different isozymes and ask to what extent such activation is specific; that is, is effective nonspecific interaction possible between LSUs and SSUs of different isozymes? To our surprise, the AHAS II SSU ilvM is able to activate the LSUs of all three of the isozymes, and the truncated AHAS III SSUs ilvH-Delta80, ilvH-Delta86 and ilvH-Delta89 are able to activate the LSUs of both AHAS I and AHAS III. However, none of the heterologously activated enzymes have any feedback sensitivity. Our results imply the existence of a common region in all three LSUs to which regulatory subunits may bind, as well as a similarity between the surfaces of ilvM and the other SSUs. This surface must be included within the N-terminal betaalphabetabetaalphabeta-domain of the SSUs, probably on the helical face of this domain. We suggest hypotheses for the mechanism of valine inhibition, and reject one involving induced dissociation of subunits. PMID:19653643

  3. Practical hyperdynamics method for systems with large changes in potential energy

    NASA Astrophysics Data System (ADS)

    Hirai, Hirotoshi

    2014-12-01

    A practical hyperdynamics method is proposed to accelerate systems with highly endothermic and exothermic reactions such as hydrocarbon pyrolysis and oxidation reactions. In this method, referred to as the "adaptive hyperdynamics (AHD) method," the bias potential parameters are adaptively updated according to the change in potential energy. The approach is intensively examined for JP-10 (exo-tetrahydrodicyclopentadiene) pyrolysis simulations using the ReaxFF reactive force field. Valid boost parameter ranges are clarified as a result. It is shown that AHD can be used to model pyrolysis at temperatures as low as 1000 K while achieving a boost factor of around 105.

  4. Practical hyperdynamics method for systems with large changes in potential energy.

    PubMed

    Hirai, Hirotoshi

    2014-12-21

    A practical hyperdynamics method is proposed to accelerate systems with highly endothermic and exothermic reactions such as hydrocarbon pyrolysis and oxidation reactions. In this method, referred to as the "adaptive hyperdynamics (AHD) method," the bias potential parameters are adaptively updated according to the change in potential energy. The approach is intensively examined for JP-10 (exo-tetrahydrodicyclopentadiene) pyrolysis simulations using the ReaxFF reactive force field. Valid boost parameter ranges are clarified as a result. It is shown that AHD can be used to model pyrolysis at temperatures as low as 1000 K while achieving a boost factor of around 10(5). PMID:25527921

  5. Registration of N6202 soybean germplasm with high protein, good yield potential, large seed and diverse pedigree

    Technology Transfer Automated Retrieval System (TEKTRAN)

    N6202 soybean [Glycine max (L.,) Merr.] was cooperatively developed and released by the USDA-ARS and the North Carolina Agricultural Research Service in 2009 as a Maturity Group VI germplasm with high-protein seed, good yield potential, large-seed size, and diverse pedigree. The unusual combinati...

  6. Large-Eddy Simulations of Turbulent Premixed Bunsen Flames at Different Turbulence Levels

    NASA Astrophysics Data System (ADS)

    Duchampde Lageneste, Laurent; Pitsch, Heinz

    2002-11-01

    In a recent study we have formulated a level-set method based on the G-equation for Large-Eddy Simulation (LES) of premixed turbulent combustion and applied the model successfully in a simulation of the turbulent Bunsen flame,F3, experimentally investigated by Chen et al. (1996). This flame is nominally in the thin reaction zones regime. As a further validation of the model and to demonstrate the benefits of LES in turbulent combustion modeling, in the present work, we report on an LES of the F2-flame from the same series of experiments, which has a higher turbulence level and hence a higher Karlovitz number. This flame is still in the thin reaction zones regime, but locally reveals regions burning in the broken reaction zones regime. Results from the simulation will be compared with experimental data for temperature and axial velocity. The experimental data shows substantial differences between flames F2 and F3, which is well described by the simulation. Flame F2, for instance, shows an almost linear increase of the flame brush thickness with downstream distance from the nozzle, whereas flame F3 shows almost constant flame brush thickness.

  7. Large current difference in Au-coated vertical silicon nanowire electrode array with functionalization of peptides

    NASA Astrophysics Data System (ADS)

    Kim, Ilsoo; Kim, So-Eun; Han, Sanghun; Kim, Hyungsuk; Lee, Jaehyung; Jeong, Du-Won; Kim, Ju-Jin; Lim, Yong-beom; Choi, Heon-Jin

    2013-11-01

    Au-coated vertical silicon nanowire electrode array (VSNEA) was fabricated using a combination of bottom-up and top-down approaches by chemical vapor deposition and complementary metal-oxide-semiconductor process for biomolecule sensing. To verify the feasibility for the detection of biomolecules, Au-coated VSNEA was functionalized using peptides having a fluorescent probe. Cyclic voltammograms of the peptide-functionalized Au-coated VSNEA show a steady-state electrochemical current behavior. Because of the critically small dimension and vertically aligned nature of VSNEA, the current density of Au-coated VSNEA was dramatically higher than that of Au film electrodes. Au-coated VSNEA further showed a large current difference with and without peptides that was nine times more than that of Au film electrodes. These results indicate that Au-coated VSENA is highly effective device to detect peptides compared to conventional thin-film electrodes. Au-coated VSNEA can also be used as a divergent biosensor platform in many applications.

  8. Modeling reactive transport of reclaimed water through large soil columns with different low-permeability layers

    NASA Astrophysics Data System (ADS)

    Hu, Haizhu; Mao, Xiaomin; Barry, D. A.; Liu, Chengcheng; Li, Pengxiang

    2015-03-01

    The efficacy of different proportions of silt-loam/bentonite mixtures overlying a vadose zone in controlling solute leaching to groundwater was quantified. Laboratory experiments were carried out using three large soil columns, each packed with 200-cm-thick riverbed soil covered by a 2-cm-thick bentonite/silt-loam mixture as the low-permeability layer (with bentonite mass accounting for 12, 16 and 19 % of the total mass of the mixture). Reclaimed water containing ammonium (NH4 +), nitrate (NO3 -), organic matter (OM), various types of phosphorus and other inorganic salts was applied as inflow. A one-dimensional mobile-immobile multi-species reactive transport model was used to predict the preferential flow and transport of typical pollutants through the soil columns. The simulated results show that the model is able to predict the solute transport in such conditions. Increasing the amount of bentonite in the low-permeability layer improves the removal of NH4 + and total phosphorous (TP) because of the longer contact time and increased adsorption capacity. The removal of NH4 + and OM is mainly attributed to adsorption and biodegradation. The increase of TP and NO3 - concentration mainly results from discharge and nitrification in riverbed soils, respectively. This study underscores the role of low-permeability layers as barriers in groundwater protection. Neglect of fingers or preferential flow may cause underestimation of pollution risk.

  9. A computationally efficient scheme for the inversion of large scale potential field data: Application to synthetic and real data

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Meng, Xiaohong; Li, Fang

    2015-12-01

    Three dimensional (3D) inversion of potential field data from large scale surveys attempts to recover density or magnetic susceptibility distribution in the subspace for geological interpretation. It is computationally challenging and is not feasible on desktop computers. We propose an integrated scheme to address this problem. We adopt adaptive sampling to compress the dataset, and the cross curve of the data compression ratio and correlation coefficient between the initial and sampled data is used to choose the damping factor for adaptive sampling. Then, the conventional inversion algorithm in model space is transformed to data space, using the identity relationship between different matrices, which greatly reduces the memory requirement. Finally, parallel computation is employed to accelerate calculation of the kernel function. We use the conjugate gradient method to minimize the objective function and a damping factor is introduced to stabilize the iterative process. A wide variety of constraint options are also considered, such as depth weighing, sparseness, and boundary limits. We design a synthetic magnetic model with three prismatic susceptibility causative bodies to demonstrate the effectiveness of the proposed scheme. Tests on synthetic data show that the proposed scheme provides significant reduction in memory and time consumption, and the inversion result is reliable. These advantages hold true for practical field magnetic data from the Hawsons mining area in Australia, verifying the effectiveness of the proposed scheme.

  10. Large diffuse halos in time-dependent space-charge potentials with colored noise

    SciTech Connect

    Courtlandt Bohn and Ioannis V. Sideris

    2003-05-22

    We explore the potential impact of colored noise on space-charge-induced halo formation. By coupling particle orbits to parametric resonance, colored noise due to space-charge fluctuations and/or imperfections in the beamline can eject particles to much larger amplitudes than would be inferred from parametric resonance alone.

  11. Consistency of mixing height retrieved over a large spatial domain from different data sources

    NASA Astrophysics Data System (ADS)

    Biavati, Gionata; Feist, Dietrich G.

    2014-05-01

    The monitoring of GreenHouse Gases (GHG) fluxes over large domains is performed coupling measurements with transport models. A key parameter, for successfully quantifying the fluxes is the altitude of the capping inversion, or the mixing height (MH). This parameter is commonly estimated as a diagnostic variable within global models, or estimated using radiosonde data. Both these methods have problems in representing the MH. In particular the time evolution and the spatial representation are the weakest aspects. Within the context of the Integrated Carbon Observation System (ICOS), a network of measurement stations is going to be created. Together with a complete equipment of instruments for measuring GHG concentrations and meteorological quantities, it is planed to monitor the MH using ceilometers and lidars. Ceilometers are a less expensive version of lidars, they are capable to estimate aerosolic load and within almost the first two kilometers the molecular density. The estimations are obtained looking for relevant time and space fluctuations of aerosol concentration. This is equivalent to placing the MH over an strong variation of the measured signal. So the most of the algorithms for locating MH are edge detection algorithms. The evaluation of the MH, estimated with different algorithms applied to optical data, shows bad agreement with the estimate performed on radiosonde data. However, a deeper study on the automated methods used on radiosonde data reveals that the commonly used algorithms, based on different implementations of Richardson Bulk Number method, are not reliable or suitable for evaluating results of other methods. The use of optical instruments for estimating MH has several limitations: multiple edges are commonly detected and a selection criteria is required; depending on the stability of the boundary layer MH can be outside the detection limits of the instrument; clouds and other water condensations phenomena can prevent the estimation of MH. Applications of such instruments is tested over a wide domain covering the German Weather Service network of ceilometers and the estimations are compared to different methods of estimating MH, in particular: geostatistical interpolation of MH estimated with radiosonde; distance weighted interpolations of MH estimated with radiosonde; direct comparison of co-located ceilometer and radiosonde. The results reveal the need of developing a more appropriate approach for using both radiosonde and optical methods in an automated context.

  12. Large-scale controls on potential respiration and denitrification in riverine floodplains

    PubMed Central

    Welti, Nina; Bondar-Kunze, Elisabeth; Singer, Gabriel; Tritthart, Michael; Zechmeister-Boltenstern, Sophie; Hein, Thomas; Pinay, Gilles

    2012-01-01

    Restoration measures of deteriorated river ecosystems generally aim at increasing the spatial heterogeneity and connectivity of these systems in order to increase biodiversity and ecosystem stability. While this is believed to benefit overall ecological integrity, consequences of such restoration projects on biogeochemical processes per se (i.e. ecosystem functioning) in fluvial systems are rarely considered. We address these issues by evaluating the characteristics of surface water connection between side arms and the main river channel in a former braided river section and the role and degree of connectivity (i.e. duration of surface water connection) on the sediment biogeochemistry. We hypothesized that potential respiration and denitrification would be controlled by the degree of hydrological connectivity, which was increased after floodplain restoration. We measured potential microbial respiration (SIR) and denitrification (DEA) and compared a degraded floodplain section of the Danube River with a reconnected and restored floodplain in the same river section. Re-establishing surface water connection altered the controls on sediment microbial respiration and denitrification ultimately impacting potential microbial activities. Meta-variables were created to characterize the effects of hydrology, morphology, and the available carbon and nutrient pools on potential microbial processing. Mantel statistics and path analysis were performed and demonstrate a hierarchy where the effects of hydrology on the available substrates and microbial processing are mediated by the morphology of the floodplain. In addition, these processes are highest in the least connected sites. Surface water connection, mediated by morphology regulates the potential denitrification rate and the ratio of N2O to N2 emissions, demonstrating the effects of restoration in floodplain systems. PMID:23565037

  13. Noise Reduction Potential of Large, Over-the-Wing Mounted, Advanced Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.

    2000-01-01

    As we look to the future, increasingly stringent civilian aviation noise regulations will require the design and manufacture of extremely quiet commercial aircraft. Indeed, the noise goal for NASA's Aeronautics Enterprise calls for technologies that will help to provide a 20 EPNdB reduction relative to today's levels by the year 2022. Further, the large fan diameters of modem, increasingly higher bypass ratio engines pose a significant packaging and aircraft installation challenge. One design approach that addresses both of these challenges is to mount the engines above the wing. In addition to allowing the performance trend towards large, ultra high bypass ratio cycles to continue, this over-the-wing design is believed to offer noise shielding benefits to observers on the ground. This paper describes the analytical certification noise predictions of a notional, long haul, commercial quadjet transport with advanced, high bypass engines mounted above the wing.

  14. Potential impacts of the Deepwater Horizon oil spill on large pelagic fishes

    NASA Astrophysics Data System (ADS)

    Frias-Torres, Sarrah; Bostater, Charles R., Jr.

    2011-11-01

    Biogeographical analyses provide insights on how the Deepwater Horizon oil spill impacted large pelagic fishes. We georeferenced historical ichthyoplankton surveys and published literature to map the spawning and larval areas of bluefin tuna, swordfish, blue marlin and whale shark sightings in the Gulf of Mexico with daily satellite-derived images detecting surface oil. The oil spill covered critical areas used by large pelagic fishes. Surface oil was detected in 100% of the northernmost whale shark sightings, in 32.8 % of the bluefin tuna spawning area and 38 % of the blue marlin larval area. No surface oil was detected in the swordfish spawning and larval area. Our study likely underestimates the extend of the oil spill due to satellite sensors detecting only the upper euphotic zone and the use of dispersants altering crude oil density, but provides a previously unknown spatio-temporal analysis.

  15. Hyperdense large artery sign in meningitis: A marker of ominous thrombogenic potential of pneumococcus?

    PubMed

    Mojumder, Deb Kumar; Toledo, John De

    2014-04-01

    Hyperdensity in the middle cerebral artery (MCA) or posterior cerebral artery (PCA) on non-contrast head CT, suggests the presence of a thrombus inside these vessels, often referred to as the "MCA sign" or "PCA sign" respectively. These two signs are classically associated with strokes secondary to cardiovascular etiologies and are only infrequently reported with other types of stroke. Whereas stroke is a recognized complication of pneumococcal meningitis hyperdense large vessel sign (in this case a combination of MCA and PCA) has not been previously reported. We report a case of rapidly progressive pneumococcal meningitis that presented as acute stroke involving large vessels in the vicinity of the circle of Willis in a patient with a history of non-Hodgkin lymphoma (NHL) in remission for 6 years. This patient had received a week of high dose steroids before admission. Head CT scan on admission showed the presence of hyperdense MCA and PCA signs. The patient rapidly deteriorated and a follow-up head CT revealed diffuse brain edema and increased density in the basal cisterns without evidence of sub arachnoid hemorrhage. Tc99m exametazime brain flow scan showed no intracerebral blood flow both supra and infratentorially. Steptococcus pneumoniae, NHL cells and high-dose steroid use can upregulate tissue factor synthesis and may have led to a hypercoagulable state via activation of the extrinsic pathway in the large intracerbral arteries. PMID:24966558

  16. Dispersal of large branchiopod cysts: Potential movement by wind from potholes on the Colorado Plateau

    USGS Publications Warehouse

    Graham, T.B.; Wirth, D.

    2008-01-01

    Wind is suspected to be a primary dispersal mechanism for large branchiopod cysts on the Colorado Plateau. We used a wind tunnel to investigate wind velocities capable of moving pothole sediment and cysts from intact and disturbed surfaces. Material moved in the wind tunnel was trapped in filters; cysts were separated from sediment and counted. Undisturbed sediment moved at velocities as low as 5.9 m s-1 (12.3 miles h-1). A single all-terrain vehicle (ATV) track increased the sediment mass collected 10-fold, with particles moving at a wind velocity of only 4.2 m s-1 (8.7 miles h-1). Cysts were recovered from every wind tunnel trial. Measured wind velocities are representative of low-wind speeds measured near Moab, Utah. Wind can move large numbers of cysts to and from potholes on the Colorado Plateau. Our results indicate that large branchiopod cysts move across pothole basins at low-wind speeds; additional work is needed to establish velocities at which cysts move between potholes. ?? 2007 Springer Science+Business Media B.V.

  17. Insights into the Carbon Sequestration Potential of Rangelands Through Measurement and Modeling of Differently Managed Pastures

    NASA Astrophysics Data System (ADS)

    Owen, J. J.; Hartman, M.; Parton, W. J.; Silver, W. L.

    2014-12-01

    Poor management of rangelands has led to significant soil organic matter losses globally, and contributed to increasing atmospheric CO2 concentrations. Restoring and increasing soil carbon (C) content in rangelands offers an opportunity to mitigate climate change while improving soil conditions and increasing forage production. Organic matter amendments are used to improve soil properties, but predicting the resulting changes in soil C is challenging due to the interactions between amendment characteristics, climate, and soil characteristics. We used data from 10 pasture-based dairies in California and the DayCent model to test the impact of long-term (>30 year) manure additions on soil C pools and fluxes. Soils were sampled from 26 fields which had solid, liquid, solid and liquid, or no manure additions. These field data and management information provided by the ranchers were used to model the effects of manure amends on soil C storage and loss. Soil C was significantly greater in manured fields than non-manured fields when corrected for clay content and slope. Fields with higher clay had more soil C, as did those with lower slopes, and these effects were large enough to confound the manuring effect. DayCent was able to accurately estimate total soil C when parameterized with field-specific management practices, averaging only a 10±1% difference between measurement and modeled values. Using generalized management histories for manured and non-manured fields, as would be used for regional-scale estimates, produced less accurate results with a 24±3% average difference between measurement and modeled values. Modeling alternate scenarios for each field suggested that manure amendment increased soil C and forage production by 0.6 Mg ha-1 y-1 and 0.3 Mg ha-1 y-1, respectively. Forecasting to 2100 showed that in manure-amended fields, soil C increased until 2080 before stabilization, mostly through gains in the pool with slow turnover. The "passive soil C" pool generally declined due to a legacy effect of the historical shift in vegetation from perennial to annual grasses, and did not recover over the timespan considered here. These results demonstrate the potential of manure amendment to increase soil C in some rangelands and the ability of DayCent to reasonably approximate changes in soil C in response to management.

  18. Comparative transforming potential of different human papillomaviruses associated with non-melanoma skin cancer

    SciTech Connect

    Massimi, Paola; Thomas, Miranda; Bouvard, Veronique; Ruberto, Irene; Campo, M. Saveria; Tommasino, Massimo; Banks, Lawrence

    2008-02-20

    It is well established that high-risk human papillomaviruses (HPVs) that infect mucosal epithelia are the causative agents of cervical cancer. In contrast, the association of cutaneo-tropic HPV types with the development of non-melanoma skin cancer (NMSC) is less well defined. In this study, we have analysed the in vitro transforming potential of various cutaneous HPV types. Using oncogene cooperation assays with activated ras, we have shown that diverse cutaneous types, including 12, 14, 15, 24, 36 and 49, have significant transforming potential. Interestingly, most of this activity appears to be encoded by the E6 gene product. In contrast, the common HPV-10 exhibits no significant transforming potential in these assays. This difference may be a reflection of different patterns of cellular localization, with transforming E6s being nuclear and non-transforming being cytoplasmic. These results provide molecular support for a role of these viruses in the development of certain human malignancies.

  19. Study Role of Different Dimensions of Emotional Self-Regulation on Addiction Potential

    PubMed Central

    Kazemi, Yahya; Khosravy, Masoum

    2014-01-01

    Objective To investigate relationship between addiction potentiality and different dimensions of emotional self-regulation. Materials and methods This descriptive and correlational study included students of Sistan and Baluchistan University, Sistan and Baluchestan, Iran. Participants were selected by random sampling method. We applied Addiction Potential Scale (APS) and Difficult in Emotion Regulation Scale (DERS) for this study. For statistical analysis, Pearson correlation and regression analysis methods were used. Results The results show that there is a positive and significant relationship between the addiction potential and all dimensions of emotional self-regulation (excepting lack of awareness). The enter regression analysis for prediction of the APS by the DERS shows that the DERS predicts 16% of the APS variances. Conclusion Regard to the results, it is necessary to introduce an especial program in emotional self-regulation for the youth with addiction potential. PMID:24971137

  20. How to Help Children with Learning Differences Reach Their Full Potential

    ERIC Educational Resources Information Center

    Lavoie, Theresa

    2008-01-01

    This article is the third part of a 10-part series that explores Attention Deficit Hyperactivity Disorder (ADHD). It offers and discusses tips on how to help children with learning differences reach their full potential. These include: (1) start with good nutrition; (2) be sure your child is exercising; (3) make sure your child is getting enough

  1. The Turn to Experience in Contemporary Art: A Potentiality for Thinking Art Education Differently

    ERIC Educational Resources Information Center

    O'Donoghue, Dnal

    2015-01-01

    This article considers the turn to experience in contemporary art and examines its potentiality for thinking art education differently. This project should not be mistaken for what Hannah Arendt (1968) identified as "the extraordinary enthusiasm for what is new" (p. 176). Rather, its purpose is to pursue another possibility for art

  2. Differences in Mathematical Performance, Creativity Potential, and Need for Cognitive Closure between Chinese and Australian Students

    ERIC Educational Resources Information Center

    Ma, Choi-Chi Evelene; Rapee, Ronald M.

    2015-01-01

    Research has shown that Chinese students outperform students from several Western countries on mathematics performance while some evidence has suggested that Western students perform more strongly on tests of creativity. One potential mechanism for these differences may be a higher need for cognitive closure among Chinese students. The current…

  3. Greenhouse gas emission and groundwater pollution potentials of soils amended with different swine biochars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to study the greenhouse gas emission and groundwater pollution potentials of the soils amended with various biochars using different biomass feedstocks and thermal processing conditions. Triplicate sets of small pots were designed; control soil consisting of Histi...

  4. Benthic Community Responses during Different Construction Stage of Large Coastal Development (Saemangeum, Republic of Korea)

    NASA Astrophysics Data System (ADS)

    Park, S.; An, S.

    2014-12-01

    The Saemangeum reclamation project in South Korea represents one of the largest construction efforts in coastal environments and provides a valuable opportunity to evaluate the benthic community responses in the large scale human disturbances. The changes of benthic ecosystems were monitored in the course of construction stage. Depending on the construction stage (Partial Closure (PC) stage: May 2004 ~Jan. 2006, Complete Closure (CC) stage: May 2006~Nov. 2006), Stable (S) stage: May 2007 ~ Aug. 2008), subtidal benthic ecosystems around Saemangeum were affected differently. In particular, the dramatic change of benthic community was observed in DI (Direct influence) area located inside the barrage. The benthic community change was temporal and minimum in the IDI (In-direct Influence) area located outside the barrage. During PC stage, the species number and density tended to increase in DI, but they rapidly decreased during CC stage. They increased again during S stage in DI but the most of the species were composed of opportunistic species indicating a deteriorated environment. In IDI, the species number and density also increased during PC stage and decreased during CC stage, but unlike DI, the increase of species number and density in S stage was not observed. In DI area, the benthic community structure had changed due to hypoxia, desalination and landization after CC stage, and the opportunistic species like Theora fragilis, Tharyx sp., Heteromastus filiformis had dominated after S-stage. In IDI area, however, abrupt environmental changes had not appeared and species number and density had been constant and species composition did not change even after the CC stage.

  5. Differential response to DNA damage may explain different cancer susceptibility between small and large intestine.

    PubMed

    Hong, Mee Young; Turner, Nancy D; Carroll, Raymond J; Chapkin, Robert S; Lupton, Joanne R

    2005-07-01

    Although large intestine (LI) cancer is the second-leading cause of cancer-related deaths in the United States, small intestine (SI) cancer is relatively rare. Because oxidative DNA damage is one possible initiator of tumorigenesis, we investigated if the SI is protected against cancer because of a more appropriate response to oxidative DNA damage compared with the LI. Sixty rats were allocated to three treatment groups: 3% dextran sodium sulfate (DSS, a DNA-oxidizing agent) for 48 hrs, withdrawal (DSS for 48 hrs + DSS withdrawal for 48 hrs), or control (no DSS). The SI, compared with the LI, showed greater oxidative DNA damage (P < 0.001) as determined using a quantitative immunohistochemical analysis of 8-oxodeoxyguanosine (8-oxodG). The response to the DNA adducts in the SI was greater than in the LI. The increase of TdT-mediated dUTP-biotin nick end labeling (TUNEL)-positive apoptosis after DSS treatment was greater in the SI compared with the LI (P < 0.001), and there was a positive correlation (P = 0.031) between DNA damage and apoptosis in the SI. Morphologically, DSS caused an extensive loss of crypt structure shown in lower crypt height (P = 0.006) and the number of intact crypts (P = 0.0001) in the LI, but not in the SI. These data suggest that the SI may be more protected against cancer by having a more dynamic response to oxidative damage that maintains crypt morphology, whereas the response of the LI makes it more susceptible to loss of crypt architecture. These differential responses to oxidative DNA damage may contribute to the difference in cancer susceptibility between these two anatomic sites of the intestine. PMID:15985621

  6. Active and total microbial communities in forest soil are largely different and highly stratified during decomposition

    PubMed Central

    Baldrian, Petr; Kolařík, Miroslav; Štursová, Martina; Kopecký, Jan; Valášková, Vendula; Větrovský, Tomáš; Žifčáková, Lucia; Šnajdr, Jaroslav; Rídl, Jakub; Vlček, Čestmír; Voříšková, Jana

    2012-01-01

    Soils of coniferous forest ecosystems are important for the global carbon cycle, and the identification of active microbial decomposers is essential for understanding organic matter transformation in these ecosystems. By the independent analysis of DNA and RNA, whole communities of bacteria and fungi and its active members were compared in topsoil of a Picea abies forest during a period of organic matter decomposition. Fungi quantitatively dominate the microbial community in the litter horizon, while the organic horizon shows comparable amount of fungal and bacterial biomasses. Active microbial populations obtained by RNA analysis exhibit similar diversity as DNA-derived populations, but significantly differ in the composition of microbial taxa. Several highly active taxa, especially fungal ones, show low abundance or even absence in the DNA pool. Bacteria and especially fungi are often distinctly associated with a particular soil horizon. Fungal communities are less even than bacterial ones and show higher relative abundances of dominant species. While dominant bacterial species are distributed across the studied ecosystem, distribution of dominant fungi is often spatially restricted as they are only recovered at some locations. The sequences of cbhI gene encoding for cellobiohydrolase (exocellulase), an essential enzyme for cellulose decomposition, were compared in soil metagenome and metatranscriptome and assigned to their producers. Litter horizon exhibits higher diversity and higher proportion of expressed sequences than organic horizon. Cellulose decomposition is mediated by highly diverse fungal populations largely distinct between soil horizons. The results indicate that low-abundance species make an important contribution to decomposition processes in soils. PMID:21776033

  7. Potential benefits of a ceramic thermal barrier coating on large power generation gas turbine

    NASA Technical Reports Server (NTRS)

    Clark, J. S.; Nainiger, J. J.

    1977-01-01

    Thermal barrier coating design option offers benefit in terms of reduced electricity costs when used in utility gas turbines. Options considered include: increased firing temperature, increased component life, reduced cooling air requirements, and increased corrosion resistance (resulting in increased tolerance for dirty fuels). Performance and cost data were obtained. Simple, recuperated and combined cycle applications were considered, and distillate and residual fuels were assumed. The results indicate that thermal barrier coatings could produce large electricity cost savings if these coatings permit turbine operation with residual fuels at distillate-rated firing temperatures. The results also show that increased turbine inlet temperature can result in substantial savings in fuel and capital costs.

  8. Analysis of Problem of High Power Fiber Laser Combining for Arbitrary Large Optical Phase Differences

    NASA Astrophysics Data System (ADS)

    Napartovich, A. P.; Elkin, N. N.; Vysotsky, D. V.

    2010-10-01

    Coherent laser beam combining is potentially attractive way to increase the combined beam brightness beyond the limits imposed on single-mode lasers by technological bounds. The active control of every individual laser beam characteristics is more flexible but essentially more complicated in both, necessary equipment and service. Passive phase locking is an attractive alternative, since it does not need external management and leads to strong simplification of the system. A specific feature of fiber amplifiers and lasers is that they possess optical path differences (OPD) of many wavelengths magnitude. Cold-cavity theory predicts in this case fast decline in efficiency of coherent fiber laser beam combining with number of lasers. Experiments, in contrast, demonstrated in such systems that high degree of phasing takes place for laser arrays of up to 16 lasers. As lasers are strong non-linear systems, explanation of this discrepancy should rely on a role of non-linear effects: gain saturation and intensity-dependent index. Besides, since the gain band width is significantly broader than the distance between spectral lines responding to different longitudinal modes, it is a freedom in adjusting laser wavelength to a value, which corresponds to a best balance between gain and loss of laser radiation. As a first step, we consider a fiber laser array with external global coupling, which means that the same fraction of the combined laser beam is returned into the each element of the array. In this case, every laser in the array is operated as an injection controlled (slave) laser. The specific features of Yb-doped fiber lasers were taken into account in our model: 1) existence of multiple longitudinal modes; 2) typically low-Q cavity used in these lasers. This approach allows us to quantify the mechanism of laser wavelength self-adjustment taking into account the effect of gain saturation. Taking the injection signal intensity within limits of locking range, the output signal was studied as a function of wavelength detuning and small signal gain magnitude. Then the maximal phase locking efficiency is found numerically as a function of coupling strength and of optical pumping intensity at random values of the OPD for laser arrays of variable size. Just the gain saturation effect taken into account in our model leads to comparatively slow reduction of the maximal phase locking efficiency with the laser array size.

  9. Influence of beverage composition on the results of erosive potential measurement by different measurement techniques.

    PubMed

    Jager, D H J; Vieira, A M; Ruben, J L; Huysmans, M C D N J M

    2008-01-01

    The influence of beverage composition on the measurement of erosive potential is unclear. The aim of this study was to evaluate whether beverage composition influences the measurement of erosive potential and to evaluate the influence of exposure in small and large volumes. Eleven beverages were included: water (control), 3 alcopops, 2 beers and 5 soft drinks. For each beverage 15 bovine enamel samples were used: 5 for chemical and 10 for profilometric analysis. After exposure to the beverages (63 min) the resulting solutions were analyzed for Ca and inorganic phosphorus (P(i)) content. The samples for optical profilometry were submersed sequentially in 500 ml or in 1 ml of the drinks for 3, 6, 9, 15 and 30 min (total 63 min). For some of the beverages high baseline concentrations of Ca (energy drink) or P(i) (cola drink, cola lemon drink, beer, beer lemon) were found. Some of the beverages showed a good correlation between the chemical methods. Profilometry (both for 1 and 500 ml) showed generally lower enamel losses than the chemical methods. Lower enamel losses were found for the profilometry 1 ml compared to the profilometry 500 ml only for the cola drinks. It can be concluded that the composition of the beverages had a significant effect on the determination of the erosive potential with chemical analyses. Drink composition also influenced the effect of small versus large exposure volumes, indicating the need for standardization of exposure parameters. PMID:18277070

  10. Spider Transcriptomes Identify Ancient Large-Scale Gene Duplication Event Potentially Important in Silk Gland Evolution.

    PubMed

    Clarke, Thomas H; Garb, Jessica E; Hayashi, Cheryl Y; Arensburger, Peter; Ayoub, Nadia A

    2015-07-01

    The evolution of specialized tissues with novel functions, such as the silk synthesizing glands in spiders, is likely an influential driver of adaptive success. Large-scale gene duplication events and subsequent paralog divergence are thought to be required for generating evolutionary novelty. Such an event has been proposed for spiders, but not tested. We de novo assembled transcriptomes from three cobweb weaving spider species. Based on phylogenetic analyses of gene families with representatives from each of the three species, we found numerous duplication events indicative of a whole genome or segmental duplication. We estimated the age of the gene duplications relative to several speciation events within spiders and arachnids and found that the duplications likely occurred after the divergence of scorpions (order Scorpionida) and spiders (order Araneae), but before the divergence of the spider suborders Mygalomorphae and Araneomorphae, near the evolutionary origin of spider silk glands. Transcripts that are expressed exclusively or primarily within black widow silk glands are more likely to have a paralog descended from the ancient duplication event and have elevated amino acid replacement rates compared with other transcripts. Thus, an ancient large-scale gene duplication event within the spider lineage was likely an important source of molecular novelty during the evolution of silk gland-specific expression. This duplication event may have provided genetic material for subsequent silk gland diversification in the true spiders (Araneomorphae). PMID:26058392

  11. Spider Transcriptomes Identify Ancient Large-Scale Gene Duplication Event Potentially Important in Silk Gland Evolution

    PubMed Central

    Clarke, Thomas H.; Garb, Jessica E.; Hayashi, Cheryl Y.; Arensburger, Peter; Ayoub, Nadia A.

    2015-01-01

    The evolution of specialized tissues with novel functions, such as the silk synthesizing glands in spiders, is likely an influential driver of adaptive success. Large-scale gene duplication events and subsequent paralog divergence are thought to be required for generating evolutionary novelty. Such an event has been proposed for spiders, but not tested. We de novo assembled transcriptomes from three cobweb weaving spider species. Based on phylogenetic analyses of gene families with representatives from each of the three species, we found numerous duplication events indicative of a whole genome or segmental duplication. We estimated the age of the gene duplications relative to several speciation events within spiders and arachnids and found that the duplications likely occurred after the divergence of scorpions (order Scorpionida) and spiders (order Araneae), but before the divergence of the spider suborders Mygalomorphae and Araneomorphae, near the evolutionary origin of spider silk glands. Transcripts that are expressed exclusively or primarily within black widow silk glands are more likely to have a paralog descended from the ancient duplication event and have elevated amino acid replacement rates compared with other transcripts. Thus, an ancient large-scale gene duplication event within the spider lineage was likely an important source of molecular novelty during the evolution of silk gland-specific expression. This duplication event may have provided genetic material for subsequent silk gland diversification in the true spiders (Araneomorphae). PMID:26058392

  12. A large-cavity zeolite with wide pore windows and potential as an oil refining catalyst.

    PubMed

    Corma, Avelino; Daz-Cabaas, Mara J; Martnez-Triguero, Joaqun; Rey, Fernando; Rius, Jordi

    2002-08-01

    Crude oil is an important feedstock for the petrochemical industry and the dominant energy source driving the world economy, but known oil reserves will cover demand for no more than 50 years at the current rate of consumption. This situation calls for more efficient strategies for converting crude oil into fuel and petrochemical products. At present, more than 40% of oil conversion is achieved using catalysts based on faujasite; this zeolite requires extensive post-synthesis treatment to produce an ultrastable form, and has a large cavity accessible through four 0.74-nm-wide windows and thus limits the access of oil molecules to the catalytically active sites. The use of zeolites with better accessibility to their active sites should result in improved catalyst efficiency. To date, two zeolites with effective pore diameters exceeding that of faujasite have been reported, but their one-dimensional pore topology excludes use in oil refining. Similarly, zeolites with large pores and a three-dimensional pore topology have been reported, but in all these materials the pore openings are smaller than in faujasite. Here we report the synthesis of ITQ-21, a zeolite with a three-dimensional pore network containing 1.18-nm-wide cavities, each of which is accessible through six circular and 0.74-nm-wide windows. As expected for a zeolite with this structure, ITQ-21 exhibits high catalytic activity and selectivity for valuable products in preliminary oil refining tests. PMID:12152074

  13. Prioritization of pharmaceuticals for potential environmental hazard through leveraging a large-scale mammalian pharmacological dataset.

    PubMed

    Berninger, Jason P; LaLone, Carlie A; Villeneuve, Daniel L; Ankley, Gerald T

    2016-04-01

    The potential for pharmaceuticals in the environment to cause adverse ecological effects is of increasing concern. Given the thousands of active pharmaceutical ingredients (APIs) that can enter the aquatic environment through human and/or animal (e.g., livestock) waste, a current challenge in aquatic toxicology is identifying those that pose the greatest risk. Because empirical toxicity information for aquatic species is generally lacking for pharmaceuticals, an important data source for prioritization is that generated during the mammalian drug development process. Applying concepts of species read-across, mammalian pharmacokinetic data were used to systematically prioritize APIs by estimating their potential to cause adverse biological consequences to aquatic organisms, using fish as an example. Mammalian absorption, distribution, metabolism, and excretion (ADME) data (e.g., peak plasma concentration, apparent volume of distribution, clearance rate, and half-life) were collected and curated, creating the Mammalian Pharmacokinetic Prioritization For Aquatic Species Targeting (MaPPFAST) database representing 1070 APIs. From these data, a probabilistic model and scoring system were developed and evaluated. Individual APIs and therapeutic classes were ranked based on clearly defined read-across assumptions for translating mammalian-derived ADME parameters to estimate potential hazard in fish (i.e., greatest predicted hazard associated with lowest mammalian peak plasma concentrations, total clearance and highest volume of distribution, half-life). It is anticipated that the MaPPFAST database and the associated API prioritization approach will help guide research and/or inform ecological risk assessment. Environ Toxicol Chem 2016;35:1007-1020. Published 2015 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America. PMID:25772004

  14. Broadband Photometry of the Large Potentially Hazardous Asteroid 138095 (2000 DK79)

    NASA Astrophysics Data System (ADS)

    Hicks, M.; Ebelhar, S.

    2013-11-01

    The Near-Earth Asteroid (NEA)138095 (2000 DK79) was discovered by the LINEAR Sky Survey on February 26, 2010 (MPEC 2000-E42). With a Minimum Orbit Intersection Distance (MOID) of 0.049 AU and an expected diameter between 1.8 km and 3 km, this object has been designated as a Potentially Hazardous Asteroid (PHA) by the Minor Planet Center. We obtained two partial nights of broadband Bessel BVRI photometry at the JPL Table Mountain 0.6-m telescope (TMO) on November 16 and 17, 2013, as summarized in Table 1.

  15. NREL Confirms Large Potential for Grid Integration of Wind, Solar Power (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

    To fully harvest the nation's bountiful wind and solar resources, it is critical to know how much electrical power from these renewable resources could be integrated reliably into the grid. To inform the discussion about the potential of such variable sources, the National Renewable Energy Laboratory (NREL) launched two key regional studies, examining the east and west sections of the U.S. power grid. The studies show that it is technically possible for U.S. power systems to integrate 20%-35% renewable electricity if infrastructure and operational improvements can be made.

  16. COMMUNALITIES AND DIFFERENCES IN FEAR POTENTIATION BETWEEN CARDIAC DEFENSE AND EYE-BLINK STARTLE

    PubMed Central

    Snchez, Mara B.; Guerra, Pedro; Muoz, Miguel A.; Mata, Jos Lus; Bradley, Margaret M.; Lang, Peter J.; Vila, Jaime

    2009-01-01

    This study examines similarities and differences in fear potentiation between two protective reflexes: cardiac defense and eye-blink startle. Women reporting intense fear of animals but low fear of blood or intense fear of blood but low fear of animals viewed pictures depicting blood or the feared animal for 6 s in 2 separate trials in counterbalanced order. An intense burst of white noise, able to elicit both a cardiac defense response and a reflexive startle blink, was presented 3.5 s after picture onset. Both cardiac and blink responses were potentiated when highly fearful individuals viewed fearful pictures. However, differences appeared concerning picture order. This pattern of results indicates communalities and differences among protective reflexes that are relevant for understanding the dynamics of emotional reflex modulation. PMID:19572906

  17. Estimating Demand Response Market Potential Among Large Commercialand Industrial Customers:A Scoping Study

    SciTech Connect

    Goldman, Charles; Hopper, Nicole; Bharvirkar, Ranjit; Neenan,Bernie; Cappers, Peter

    2007-01-01

    Demand response is increasingly recognized as an essentialingredient to well functioning electricity markets. This growingconsensus was formalized in the Energy Policy Act of 2005 (EPACT), whichestablished demand response as an official policy of the U.S. government,and directed states (and their electric utilities) to considerimplementing demand response, with a particular focus on "price-based"mechanisms. The resulting deliberations, along with a variety of stateand regional demand response initiatives, are raising important policyquestions: for example, How much demand response is enough? How much isavailable? From what sources? At what cost? The purpose of this scopingstudy is to examine analytical techniques and data sources to supportdemand response market assessments that can, in turn, answer the secondand third of these questions. We focus on demand response for large(>350 kW), commercial and industrial (C&I) customers, althoughmany of the concepts could equally be applied to similar programs andtariffs for small commercial and residential customers.

  18. Termites: a potentially large source of atmospheric methane, carbon dioxide, and molecular hydrogen

    SciTech Connect

    Zimmerman, P.R.; Greenberg, J.P.; Wandiga, S.O.; Crutzen, P.J.

    1982-11-01

    Termites are emitting large quantities of CH/sub 4/, CO/sub 2/, and H/sub 2/ into the atmosphere, especially in cleared tropical forest areas. Researchers estimate that these annual global emissions could amount to 0.3 trillion lb of CH/sub 4/, 11 trillion lb of CO/sub 2/ (more than twice the net global input from fossil-fuel combustion), and 0.4 trillion lb of H/sub 2/. However, they stress that because of many uncertainties, the acutal production of these gases could vary by a factor of two; i.e., methane production could range from 0.2 to 0.7 trillion lb. Occurring on about two-thirds of the earth's

  19. Large scale integration of graphene transistors for potential applications in the back end of the line

    NASA Astrophysics Data System (ADS)

    Smith, A. D.; Vaziri, S.; Rodriguez, S.; stling, M.; Lemme, M. C.

    2015-06-01

    A chip to wafer scale, CMOS compatible method of graphene device fabrication has been established, which can be integrated into the back end of the line (BEOL) of conventional semiconductor process flows. In this paper, we present experimental results of graphene field effect transistors (GFETs) which were fabricated using this wafer scalable method. The carrier mobilities in these transistors reach up to several hundred cm2 V-1 s-1. Further, these devices exhibit current saturation regions similar to graphene devices fabricated using mechanical exfoliation. The overall performance of the GFETs can not yet compete with record values reported for devices based on mechanically exfoliated material. Nevertheless, this large scale approach is an important step towards reliability and variability studies as well as optimization of device aspects such as electrical contacts and dielectric interfaces with statistically relevant numbers of devices. It is also an important milestone towards introducing graphene into wafer scale process lines.

  20. Pathogenesis and classification of intrahepatic cholangiocarcinoma: different characters of perihilar large duct type versus peripheral small duct type.

    PubMed

    Aishima, Shinichi; Oda, Yoshinao

    2015-02-01

    Intrahepatic cholangiocarcinomas (ICCs) are made up of heterogenous carcinomas arising from different anatomical sites of the liver. Two types of candidate stem/progenitor cells of the biliary tree are postulated to exist at the peribiliary glands for large bile ducts and at the canals of Hering for small ducts and hepatocytes. According to the recent observations, ICCs can be subclassified into two types: tumors involving the large bile ducts comparable in size to the intrahepatic second branches and composed of a tubular or papillary component with tall columnar epithelium, and tumors involving the smaller duct than segmental branches and composed of small tubules with cuboidal epithelium. Perihilar large duct type ICCs can be interpreted as arising from large bile duct type ICCs, and peripheral small duct type ICCs may arise from small bile duct type or ductular type ICCs. Chronic biliary inflammation induces neoplastic change of the large bile ducts and thereby progression to the perihilar large duct type ICC, which can be grossly classified into periductal filtrating type ICC and intraductal growth type ICC, while chronic hepatitis or cirrhosis induces mass-forming peripheral small duct type ICC. The different morphological and molecular features, including stromal components and tumor vasculature, support the hypothesis that perihilar large duct type ICCs and peripheral small duct type ICCs arise from different backgrounds, have different carcinogenetic pathways, and exhibit different biologic behaviors. PMID:25181580

  1. Broadband Photometry of 2012 LZ1: A Large, Dark Potentially Hazardous Asteroid

    NASA Astrophysics Data System (ADS)

    Hicks, M.; Smythe, W.; Davtyan, T.; Dombroski, D.; Strojia, C.; Teague, S.

    2012-07-01

    2012 LZ1 was discovered on June 10, 2012 by R. McNaught (MPEC 2012-L30). The NEO passed within 0.0364 AU of the Earth on June 14.96 2012 and has been designated as a Potentially Hazardous Asteroid (PHA) by the IAU Minor Planet Center. We obtained 5 nights of time-resolved photometry at the JPL Table Mountain Observatory (TMO) 0.6-m telescope, as summarized in Table 1. Due to a high rate of motion and background star density it was necessary to minimize contamination by creating a running sky background template using adjacent frames and subtracting this template from each R-band frame, as shown in Figure 1.

  2. [Measurement of nasal transepithelial potential difference: a diagnostic test for cystic fibrosis].

    PubMed

    Charfi, M R; Matran, R; Regnard, J; Lockhart, A

    1996-01-01

    Measurement of nasal transepithelial potential difference allows the exploration of transepithelial ionic transports in vivo. Cystic fibrosis is an interesting indication of this test. Indeed, this disease is characterized by a chloride and water secretion deficit across respiratory epithelium. We have measured nasal potential in 8 healthy volunteers. Measurements were repeated 3 times a day, during 3 days for each subject. The reproducibility of the data was analysed with factorial variance model. The mean nasal potential in the healthy volunteers group and in 10 patients with cystic fibrosis was compared. In the cystic fibrosis group, the nasal potential was measured 3 times with a 2 mn-interval between the measurements. No significant variation of the nasal potential values was found from day to day or in the same day from one measurement to another. Mean value was -19 +/- 3.5 mv in normal subjects and -42.6 +/- 5.1 mv in cystic fibrosis patients. We conclude that nasal potential measurement is an easy and reproducible test that might be a complementary tool routinely used along with the classical tests in the diagnosis of cystic fibrosis. PMID:8731749

  3. Do differences in carbon allocation strategy account for large difference in productivity among four tropical Eucalyptus plantations?

    NASA Astrophysics Data System (ADS)

    Epron, D.; Nouvellon, Y.; Laclau, J.; Kinana, A.; Mazoumbou, J.; Almeida, J. D.; Deleporte, P.; Gonalves, J.; Bouillet, J.

    2010-12-01

    The increasing demand for wood products is not satisfied by natural forests, and forest plantations are expected to provide a larger part of the global wood supply in the future. Eucalyptus is the dominant species planted in the tropics. Intensification of wood production will rely mainly on gain of productivity and on extension of afforested area on marginal zones. Wood production does not only depend on gross primary production (GPP) but also on carbon partitioning between growth (NPP) and respiration, and on NPP partitioning among the different plant organs (allocation). Less than one third of GPP is allocated to wood production in planted forest ecosystems and we hypothesized that this fraction varies among genotypes, or because of soil fertility, in relation to productivity. The partitioning of aboveground NPP between leaf, branch and stem growth was compared in four Eucalyptus plantations located in Congo and Brazil over an entire rotation (6 years). In addition, total below ground carbon allocation was estimated from soil respiration and litter fall measurements. Two clones differing in productivity were studies in Congo where productivity is known to be much less important than in Brazil. Two plots (fertilized or not with K) were studied in Brazil. In Congo, the wood production was twice higher in the most productive clone (UG) compared to the less productive one (PF1). This was due to a higher aboveground NPP, the surplus being allocated to wood production. In addition, an increase in leaf lifespan reduced the amount of carbon allocated to leaf production. Similar conclusions can be drawn when comparing K+ fertilised and control stand in Brazil where most of the surplus of aboveground NPP in fertilised plots was allocated to wood production and where leaf lifespan was also increased. Soil respiration increased in both sites with increasing NPP reflecting that more carbon is allocated below ground in these stands. A better understanding of genetic and environmental control on carbon allocation is required for accurately predicted tree yield, especially in marginal area where plantations are thought to extent.

  4. Isotropic Negative Area Compressibility over Large Pressure Range in Potassium Beryllium Fluoroborate and its Potential Applications in Deep Ultraviolet Region.

    PubMed

    Jiang, Xingxing; Luo, Siyang; Kang, Lei; Gong, Pifu; Yao, Wenjiao; Huang, Hongwei; Li, Wei; Huang, Rongjin; Wang, Wei; Li, Yanchun; Li, Xiaodong; Wu, Xiang; Lu, Peixiang; Li, Laifeng; Chen, Chuangtian; Lin, Zheshuai

    2015-09-01

    Isotropic negative area compressibility, which is very rare, is observed in KBBF and the related mechanism is investigated by combined high-pressure X-ray diffraction (XRD) experiments and first-principles calculations. The strong mechanical anisotropy leads to a large Poisson's ratio and high figure of merit for the acoustic-optics effect, giving KBBF potential applications as smart strain converters and deep-ultraviolet (DUV) acoustic-optic devices. PMID:26184364

  5. Potential nucleation scavenging of smoke particles over large fires: A parametric study

    SciTech Connect

    Edwards, L.L.; Penner, J.E.

    1987-08-01

    During hypothesized nuclear exchanges massive fires may be ignited and inject large amounts of smoke into the atmosphere. Considerable evidence has been accumulated to suggest that nucleation scavenging where smoke particles serve as cloud condensation nuclei (CCN) may be an important mechanism for incorporating these particles into cloud water. The fraction of smoke particles that act as CCN depends on the cloud environment as well as the affinity of the smoke particles to water. A numerical model of the detailed microphysics of condensation growth on aerosol and cloud drop distributions is employed to produce a parametric study of the dependence of nucleation to a range of conditions. We consider aerosol number concentrations of 10/sup 9//m/sup 3/ to 10/sup 13//m/sup 3/, updraft speeds from 1 to 100 m/s and aerosol particles from fully water soluble to insoluble but wettable. The study provides insight into how well we must characterize smoke particles in order to predict the fraction that act as CCN given the dynamical environment.

  6. Inhibition of large T antigen ATPase activity as a potential strategy to develop anti-polyomavirus JC drugs

    PubMed Central

    Randhawa, Parmjeet; Zeng, G.; Bueno, M.; Salgarkar, A.; Lesniak, Andrew; Isse, K.; Seyb, K.; Perry, A.; Charles, I.; Hustus, C.; Huang, M.; Smith, M.; Glicksman, Marcie A.

    2014-01-01

    Introduction This study evaluates polyomavirus JC (JCV) large T antigen (LTA) as a potential target for drug development. LTA is a hexameric protein with a helicase activity that is powered by ATP binding and hydrolysis. The helicase and ATPase function is critical for viral replication. Methods Recombinant JCV LTA was produced in an Escherichia coli based expression plasmid. ATPase activity was measured using the malachite green assay. A high throughput screen was completed using a brain-biased library of 75,000 drug-like compounds selected for physicochemical properties consistent with blood brain barrier permeability. Results Five compounds showed non-competitive inhibition of ATPase activity with an EC50 ≤ 15 μM. Modest antiviral activity was demonstrated in an immunofluorescence assay for JCV VP-1 expression in COS7 cells (EC50 15, 18, 20, 27, and 52 μM respectively). The compounds also inhibited viral replication in a real time PCR assay at comparable concentrations. LD50 in the MTS96 and Cell TiterGlo assays was >100 μM for all compounds in COS7 as well as HEK293 cells. However, two compounds inhibited cell proliferation in culture with IC50 values of 43 and 34 μM respectively. Despite substantial amino acid similarity between polyomavirus JC, BK and SV40 proteins, these compounds differ from those previously reported to inhibit SV40 LTA ATPase in chemical structure as well as a non-competitive mechanism of inhibition. Conclusion LTA ATPase is a valid target for discovery. Additional screening and chemical optimization is needed to develop clinically useful compounds with less toxicity, which should be measured by metabolic as well as cell proliferation assays. PMID:25453344

  7. Antioxidant, total phenolic contents and antinociceptive potential of Teucrium stocksianum methanolic extract in different animal models

    PubMed Central

    2014-01-01

    Background Oxidative stress and analgesia are connected with different pathological conditions. The drug candidates from synthetic sources are associated with various side effects; therefore, researchers are giving priority to find novel, effective and safe phytomedicines. Teucrium species possesses antioxidant, analgesic, anti-inflammatory and hepatoprotective activities. The essential oils of Teucrium stocksianum have shown strong antinociceptive potential. Our current study is designed to embark total phenolic content (TPC), antioxidant and antinociceptive potential of the methanolic extract of Teucrium stocksianum (METS). Method Phytochemical composition was determined by using standard methods. Free radical scavenging potential and TPC of METS were assessed by using 2, 2-diphenyl-1-picryl-hydrazyl (DPPH) and Folin-Ciocalteu Reagent (FCR) respectively. Antinociceptive potential was determined by acetic acid induced abdominal writhing, formalin induced paw licking and tail immersion tests. Different test dose 50, 100 and 150 mg/kg body weight of METS were administered intra peritonealy (i.p) to various groups of mice for the evaluation of analgesic potential. Results Phytochemical screening confirmed the presence of flavonoids, tannins, saponins, anthraquinone, steroid, phlobatannin, terpenoid, glycoside and reducing sugars. METS was found safe at a dose of 1000 mg/kg body weight. A concentration dependent free radical scavenging effect was observed with methanolic aerial parts extract of Teucrium stocksianum (MAPETS) and methanolic roots extracts of Teucrium stocksianum (MRETS). MAPETS and MRETS have shown highest antioxidant activity 91.72% and 86.19% respectively at 100 ?g/ml. MAPETS was found more rich (115.32 mg of GAE/g of dry material) in TPC as compared to MAPETS (105.41 mg of GAE/g). METS demonstrated a dose dependent antinociceptive potential in different pain models, like in acetic acid, formalin and tail immersion showing 83.103%, 80.872% and 67.58% at a dose of 150 mg/kg, similar to acetylsalicylic acid (74.79%, 82.87%, 100 mg/kg) and TramadolR (74%, 30 mg/kg) respectively. Conclusion Strong antioxidant potential and high TPCs are residing in the methanolic extract of T. stocksianum. METS showed analgesic potential in all models of nociception implying that both peripheral and central pathways of analgesia are involved. This might be due to the presence of various classes of phytochemicals in the plant extract. PMID:24893601

  8. Evidence for a difference in rupture initiation between small and large earthquakes.

    PubMed

    Colombelli, S; Zollo, A; Festa, G; Picozzi, M

    2014-01-01

    The process of earthquake rupture nucleation and propagation has been investigated through laboratory experiments and theoretical modelling, but a limited number of observations exist at the scale of earthquake fault zones. Distinct models have been proposed, and whether the magnitude can be predicted while the rupture is ongoing represents an unsolved question. Here we show that the evolution of P-wave peak displacement with time is informative regarding the early stage of the rupture process and can be used as a proxy for the final size of the rupture. For the analysed earthquake set, we found a rapid initial increase of the peak displacement for small events and a slower growth for large earthquakes. Our results indicate that earthquakes occurring in a region with a large critical slip distance have a greater likelihood of growing into a large rupture than those originating in a region with a smaller slip-weakening distance. PMID:24887597

  9. Semiconducting large bandgap oxides as potential thermoelectric materials for high-temperature power generation?

    NASA Astrophysics Data System (ADS)

    Backhaus-Ricoult, M.; Rustad, J.; Moore, L.; Smith, C.; Brown, J.

    2014-08-01

    Semiconducting large bandgap oxides are considered as interesting candidates for high-temperature thermoelectric power generation (700-1,200 °C) due to their stability, lack of toxicity and low cost, but so far they have not reached sufficient performance for extended application. In this review, we summarize recent progress on thermoelectric oxides, analyze concepts for tuning semiconductor thermoelectric properties with view of their applicability to oxides and determine key drivers and limitations for electrical and thermal transport properties in oxides based on our own experimental work and literature results. For our experimental assessment, we have selected representative multicomponent oxides that range from materials with highly symmetric crystal structure (SrTiO3 perovskite) over oxides with large densities of planar crystallographic defects (Ti n O2 n-1 Magnéli phases with a single type of shear plane, NbO x block structures with intersecting shear planes and WO3- x with more defective block and channel structures) to layered superstructures (Ca3Co4O9 and double perovskites) and also include a wide range of their composites with a variety of second phases. Crystallographic or microstructural features of these oxides are in 0.3-2 nm size range, so that oxide phonons can efficiently interact with them. We explore in our experiments the effects of doping, grain size, crystallographic defects, superstructures, second phases, texturing and (to a limited extend) processing on electric conductivity, Seebeck coefficient, thermal conductivity and figure of merit. Jonker and lattice-versus-electrical conductivity plots are used to compare specific materials and material families and extract levers for future improvement of oxide thermoelectrics. We show in our work that oxygen vacancy doping (reduction) is a more powerful driver for improving the power factor for SrTiO3, TiO2 and NbO x than heterovalent doping. Based on our Seebeck-conductivity plots, we derived a set of highest achievable power factors. We met these best values in our own experiments for our titanium oxide- and niobium oxide-based materials. For strontium titanate-based materials, the estimated highest power factor was not reached; further material improvement is possible and can be reached for materials with higher carrier densities. Our results show that periodic crystallographic defects and superstructures are most efficient in reducing the lattice thermal conductivity in oxides, followed by hetero- and homovalent doping. Due to the small phonon mean free path in oxides, grain boundary scattering in nanoceramics or materials with nanodispersions is much less efficient. We investigated the impact of texturing in Ca3Co4O9 ceramics on thermoelectric performance; we did not find any improvement in the overall in-plane performance of a textured ceramic compared to the corresponding random ceramic.

  10. The Southern African Large Telescope (SALT) and the potential for galactic dynamical studies

    NASA Astrophysics Data System (ADS)

    Buckley, David A. H.

    1999-12-01

    Over the next 5 years or so, an international consortium lead by South Africa plans to build an 8-10 m class telescope - the Southern African Large Telescope (SALT) - modelled closely on the novel design of the Hobby-Eberly Telescope (HET) in west Texas. These telescopes represent new paradigms in design, at ~ 20% of the cost of conventional telescopes. SALT will be operated as a queue-scheduled telescope and is primarily designed for spectroscopic observations. I review the characteristics of SALT and discuss the major science drivers, which will decide the probable choice of a first-light instrument package, yet to be defined. This will likely include multi-object spectroscopic capability over a wavelength range of at least 400 nm to 1700 nm and with resolving powers of at least R ~ 300-20000, using both fibre-fed and imaging spectrographs. The former will include provision for long-slit and integral field unit fibre arrangements. A Fabry-Perot etalon may also be employed to enable 2-D imaging spectroscopy of particular spectral lines. It is possible that the instrument suite eventually chosen for SALT may have extended capabilities, both in wavelength (perhaps 350 nm <~ ? <~ 2500 nm) and resolution limit (R up to ~ 100 000). I review some of the possible science applications of SALT. Studies in the area of galactic dynamics could include dark matter in elliptical galaxies, galaxy formation and evolution, galaxy rotation curves and applications to general surveys (e.g. the HST Medium Deep Survey; XMM).

  11. Calculation of large ion densities under HVdc transmission lines by the finite difference method

    SciTech Connect

    Suda, Tomotaka; Sunaga, Yoshitaka

    1995-10-01

    A calculation method for large ion densities (charged aerosols) under HVdc transmission lines was developed considering both the charging mechanism of aerosols by small ions and the drifting process by wind. Large ion densities calculated by this method agreed well with the ones measured under the Shiobara HVdc test line on the lateral profiles at ground level up to about 70m downwind from the line. Measured values decreased more quickly than calculated ones farther downwind from the line. Considering the effect of point discharge from ground cover (earth corona) improved the agreement in the farther downwind region.

  12. Damage mechanism at different transpassive potentials of solution-annealed 316 and 316l stainless steels

    NASA Astrophysics Data System (ADS)

    Morshed Behbahani, K.; Pakshir, M.; Abbasi, Z.; Najafisayar, P.

    2015-01-01

    Electrochemical impedance spectroscopy (EIS), anodic polarization and scanning electron microscopy techniques were used to investigate the damage mechanism in the transpassive potential region of AISI 316 and AISI 316L solution-annealed stainless steels (SS) with different degrees of sensitization. Depending on the DC potential applied during EIS tests, the AC responses in the transpassive region included three different regions: the first one associated with anodic dissolution of the passive layer, the second one contributed to the dissolution at the area near grain boundaries, and the last one attributed to pitting corrosion. In addition, the fitting results to experimental data showed that as the DC bias during the EIS test increases the charge transfer resistance ( R ct) decreases. Moreover, the R ct values decreased as the sensitization temperature increases but the AISI 316L SS samples exhibited a higher resistance to intergranular corrosion than 316 SS samples.

  13. Antioxidative and antiinflammatory potential of different functional drink concepts in vitro.

    PubMed

    Dartsch, Peter C; Kler, Adolf; Kriesl, Erwin

    2009-02-01

    The present study was undertaken to investigate the antioxidative effects of three different functional drink concepts especially designed to improve the body's performance and function and to possess high antioxidant activities. The concepts based on the mixture of various plant ingredients were: (1) eQ - equalize your nutrient balance, brain line [acerola-dragon fruit], (2) eQ - equalize your nutrient balance, beauty line [honey-pepper] and (3) Let's get red [intense]. By using a cell-based test assay, the study investigated the potential of the functional drinks to inactivate reactive superoxide anion radicals generated by inflammation-mediating cells as well as the effect on basal metabolism of these cells (antioxidant and antiinflammatory potential). In addition, by using a cell-free test assay the potential of the drinks to inactivate free exogenous superoxide anion radicals (scavenger effect) was investigated. The data presented here demonstrate the different radical scavenging, antioxidant and anti-inflammatory potential of the functional drink concepts. In particular Let's get red [intense] turned out to be the most potent drink in this respect and demonstrated marked efficacy in scavenging, antioxidant and antiinflammatory action. PMID:18979495

  14. Self-Constrained Euler Deconvolution Using Potential Field Data of Different Altitudes

    NASA Astrophysics Data System (ADS)

    Zhou, Wenna; Nan, Zeyu; Li, Jiyan

    2016-02-01

    Euler deconvolution has been developed as almost the most common tool in potential field data semi-automatic interpretation. The structural index (SI) is a main determining factor of the quality of depth estimation. In this paper, we first present an improved Euler deconvolution method to eliminate the influence of SI using potential field data of different altitudes. The different altitudes data can be obtained by the upward continuation or can be directly obtained by the airborne measurement realization. Euler deconvolution at different altitudes of a certain range has very similar calculation equation. Therefore, the ratio of Euler equations of two different altitudes can be calculated to discard the SI. Thus, the depth and location of geologic source can be directly calculated using the improved Euler deconvolution without any prior information. Particularly, the noise influence can be decreased using the upward continuation of different altitudes. The new method is called self-constrained Euler deconvolution (SED). Subsequently, based on the SED algorithm, we deduce the full tensor gradient (FTG) calculation form of the new improved method. As we all know, using multi-components data of FTG have added advantages in data interpretation. The FTG form is composed by x-, y- and z-directional components. Due to the using more components, the FTG form can get more accurate results and more information in detail. The proposed modification method is tested using different synthetic models, and the satisfactory results are obtained. Finally, we applied the new approach to Bishop model magnetic data and real gravity data. All the results demonstrate that the new approach is utility tool to interpret the potential field and full tensor gradient data.

  15. A test of stress, cues, and re-exposure to large wins as potential reinstaters of suboptimal decision making in rats.

    PubMed

    Connolly, Nina P; Kim, Jung S; Tunstall, Brendan J; Kearns, David N

    2015-01-01

    The present experiment investigated potential reinstaters of suboptimal economic decision making in rats. Rats were first trained on a version of the rat Gambling Task under conditions designed to promote choice of a suboptimal option that occasionally resulted in large "wins" (four sucrose pellets). In a second phase, preference for this economically suboptimal option was reduced by substantially increasing the probability of punishment when this option was chosen. Then, three events were tested for their ability to reinstate choice of the suboptimal option. A brief period of re-exposure to a high frequency of large wins significantly increased choice of the suboptimal option. The pharmacological stressor yohimbine did not reinstate suboptimal choice, but did increase impulsive action as indexed by premature responding. Presentation of cues previously associated with large wins did not alter behavior. Results suggest reinstaters of suboptimal choice may differ from reinstaters of extinguished drug- and food-seeking behavior. PMID:25904885

  16. A test of stress, cues, and re-exposure to large wins as potential reinstaters of suboptimal decision making in rats

    PubMed Central

    Connolly, Nina P.; Kim, Jung S.; Tunstall, Brendan J.; Kearns, David N.

    2015-01-01

    The present experiment investigated potential reinstaters of suboptimal economic decision making in rats. Rats were first trained on a version of the rat Gambling Task under conditions designed to promote choice of a suboptimal option that occasionally resulted in large wins (four sucrose pellets). In a second phase, preference for this economically suboptimal option was reduced by substantially increasing the probability of punishment when this option was chosen. Then, three events were tested for their ability to reinstate choice of the suboptimal option. A brief period of re-exposure to a high frequency of large wins significantly increased choice of the suboptimal option. The pharmacological stressor yohimbine did not reinstate suboptimal choice, but did increase impulsive action as indexed by premature responding. Presentation of cues previously associated with large wins did not alter behavior. Results suggest reinstaters of suboptimal choice may differ from reinstaters of extinguished drug- and food-seeking behavior. PMID:25904885

  17. Generalized energy and potential enstrophy conserving finite difference schemes for the shallow water equations

    NASA Technical Reports Server (NTRS)

    Abramopoulos, Frank

    1988-01-01

    The conditions under which finite difference schemes for the shallow water equations can conserve both total energy and potential enstrophy are considered. A method of deriving such schemes using operator formalism is developed. Several such schemes are derived for the A-, B- and C-grids. The derived schemes include second-order schemes and pseudo-fourth-order schemes. The simplest B-grid pseudo-fourth-order schemes are presented.

  18. Comparative study of the osteogenic ability of four different ceramic constructs in an ectopic large animal model.

    PubMed

    Viateau, Véronique; Manassero, Mathieu; Sensébé, Luc; Langonné, Alain; Marchat, David; Logeart-Avramoglou, Delphine; Petite, Hervé; Bensidhoum, Morad

    2016-03-01

    Tissue-engineered constructs combining bone marrow mesenchymal stem cells with biodegradable osteoconductive scaffolds are very promising for repairing large segmental bone defects. Synchronizing and controlling the balance between scaffold-material resorption and new bone tissue formation are crucial aspects for the success of bone tissue engineering. The purpose of the present study was to determine, and compare, the osteogenic potential of ceramic scaffolds with different resorbability. Four clinically relevant granular biomaterial scaffolds (specifically, Porites coral, Acropora coral, beta-tricalcium phosphate and banked bone) with or without autologous bone marrow stromal cells were implanted in the ectopic, subcutaneous-pouch sheep model. Scaffold material resorption and new bone formation were assessed eight weeks after implantation. New bone formation was only detected when the biomaterial constructs tested contained MSCs. New bone formation was higher in the Porites coral and Acropora coral than in either the beta-tricalcium phosphate or the banked bone constructs; furthermore, there was a direct correlation between scaffold resorption and bone formation. The results of the present study provide evidence that, among the biomaterials tested, coral scaffolds containing MSCs promoted the best new bone formation in the present study. Copyright © 2013 John Wiley & Sons, Ltd. PMID:23784976

  19. Performance assessment of different constraining potentials in computational structure prediction for disulfide-bridged proteins.

    PubMed

    Kondov, Ivan; Verma, Abhinav; Wenzel, Wolfgang

    2011-08-10

    The presence of disulfide bonds in proteins has very important implications on the three-dimensional structure and folding of proteins. An adequate treatment of disulfide bonds in de-novo protein simulations is therefore very important. Here we present a computational study of a set of small disulfide-bridged proteins using an all-atom stochastic search approach and including various constraining potentials to describe the disulfide bonds. The proposed potentials can easily be implemented in any code based on all-atom force fields and employed in simulations to achieve an improved prediction of protein structure. Exploring different potential parameters and comparing the structures to those from unconstrained simulations and to experimental structures by means of a scoring function we demonstrate that the inclusion of constraining potentials improves the quality of final structures significantly. For some proteins (1KVG and 1PG1) the native conformation is visited only in simulations in presence of constraints. Overall, we found that the Morse potential has optimal performance, in particular for the ?-sheet proteins. PMID:21864792

  20. Effect of Different Tube Potential Settings on Caries Detection using PSP Plate and Conventional Film

    PubMed Central

    Cruz, Adriana Dibo; Melo, Saulo Leonardo Sousa; De Farias, Julyanna Filgueiras GonçAlves; Haiter-Neto, Francisco; De Almeida, Solange Maria

    2015-01-01

    Purpose To compare intraoral Phosphor Stimulable Plate digital system and intraoral film using different tube settings on incipient proximal caries detection. Materials and Methods Five blocks, with five teeth each, were radiographically examined using phosphor plates and F-speed films. The images were acquired in 07 different tube potentials from 50-80 kV. The films were digitized. Three oral radiologists scored the images for the presence of caries using a 5-point rating scale. The areas under ROC curve were calculated. The influence of tube kilovoltage was verified by ANOVA and pair wise comparisons performed using Tukey test. Results Mean ROC curve areas varied from 0.446-0.628 for digital images and 0.494–0.559 for conventional images. The tube setting of 70 kV presented the best result both for digital and conventional images. Considering the image type separately, 70 kV scored highest followed by 75 and 65 kV for digital images (p=0.084). For conventional image modality, even though 70 kV presented the best result, it did not differ significantly from 80 kV, not differing from 60 and 55 kV, which did not differ from 75, 65 and 50 kV (p=0.53). Conclusion Phosphor plate digital images seem to be more susceptible to tube setting potential variations then digitized film images. PMID:26023645

  1. Evaluation of the potential impact of age- and gender-specific pharmacokinetic differences on tissue dosimetry.

    PubMed

    Clewell, Harvey J; Gentry, P Robinan; Covington, Tammie R; Sarangapani, Ramesh; Teeguarden, Justin G

    2004-06-01

    The physiological and biochemical processes that determine the tissue concentration time courses (pharmacokinetics) of xenobiotics vary, in some cases significantly, with age and gender. While it is known that age- and gender-specific differences have the potential to affect tissue concentrations and, hence, individual risk, the relative importance of the contributing processes and the quantitative impact of these differences for various life stages are not well characterized. The objective of this study was to identify age- and gender-specific differences in physiological and biochemical processes that affect tissue dosimetry and integrate them into a predictive physiologically based pharmacokinetic (PBPK) life-stage model. The life-stage model was exercised for several environmental chemicals with a variety of physicochemical, biochemical, and mode-of-action properties. In general, predictions of average pharmacokinetic dose metrics for a chemical across life stages were within a factor of two, although larger transient variations were predicted, particularly during the neonatal period. The most important age-dependent pharmacokinetic factor appears to be the potential for decreased clearance of a toxic chemical in the perinatal period due to the immaturity of many metabolic enzyme systems, although this same factor may also reduce the production of a reactive metabolite. Given the potential for age-dependent pharmacodynamic factors during early life, there may be chemicals and health outcomes for which decreased clearance over a relatively brief period could have a substantial impact on risk. PMID:15056818

  2. Expression of Twist gene in human hepatocellular carcinoma cell strains of different metastatic potential.

    PubMed

    Zhu, Qian; Xu, Hubo; Xu, Qian; Yan, Wei; Tian, De'an

    2008-04-01

    In order to investigate the role of Twist gene in the metastasis of hepatocellular carcinoma (HCC), total RNA was respectively extracted from three HCC cell strains with different metastatic potentials, HepG2, MHCC-97L and MHCC-97H. The first strand cDNA was synthesized by reverse transcription, which was then used as template to perform fluorescent quantitative polymerase chain reaction (FQ-PCR). The quantity of Twist gene expression was normalized by that of the housekeeping gene, GAPDH for each sample. ANOVA was used to estimate the relationship between Twist gene and metastasis potential of HCC. The results showed that the normalized initial cDNA concentrations of Twist gene in HepG2, MHCC-97L and MHCC-97H were (9.45+/-0.25)x10(-4), (1.82+/-0.41)x10(-3), (3.06+/-0.62)x10(-3), respectively. FQ-PCR revealed significant differences in the expression level of Twist among HCC cell strains with different metastatic potentials. It was concluded that high expression level of Twist was closely associated with more aggressive behaviors of HCC. Twist provides a novel indicator for HCC metastasis. PMID:18480983

  3. Side-difference of vestibular evoked myogenic potentials in healthy subjects.

    PubMed

    Young, Yi-Ho; Kuo, Shih-Wei

    2004-12-01

    The aim of this study was to investigate the side-difference of vestibular evoked myogenic potentials (VEMPs) in relation to the provocation rates, latencies and amplitudes using binaural acoustic stimulation with bilateral recording. Fourteen healthy volunteers underwent a serial VEMP testings elicited binaurally by a sequence of alternating stimulus intensities, that is, 95-95 (right-left), 85-95, 95-85, and 85-85 dBHL tone burst, respectively. The provocation rates as well as the mean latencies of p13 and n23 for the VEMPs demonstrated no significant side-difference despite using 95-95, 85-95, 95-85 and 85-85 dBHL binaural acoustic stimulation. In contrast, nine (64%) of the 14 subjects showed side-difference of absolute p13-n23 amplitude, including right side dominant in five subjects, and left side dominant in four subjects. However, there was no significant side-difference in terms of relative amplitude despite using 95-95, 85-95, 95-85 and 85-85 dBHL binaural acoustic stimulation. Furthermore, the relative amplitude or interaural amplitude difference (IAD) ratios between those with and without side-difference of p13-n23 amplitude did not differ significantly. Hence, this study provides a potentially important method for adjusting the side difference of p13-n23 amplitudes by using a relative amplitude or IAD ratio adjustment. It also adds confidence to the successful use of binaural stimulation and recording of VEMPs under conditions of bilateral SCM muscular contractions. PMID:15567606

  4. Insects in confined swine operations carry a large antibiotic resistant and potentially virulent enterococcal community

    PubMed Central

    2011-01-01

    Background Extensive use of antibiotics as growth promoters in the livestock industry constitutes strong selection pressure for evolution and selection of antibiotic resistant bacterial strains. Unfortunately, the microbial ecology and spread of these bacteria in the agricultural, urban, and suburban environments are poorly understood. Insects such as house flies (Musca domestica) and German cockroaches (Blattella germanica) can move freely between animal waste and food and may play a significant role in the dissemination of antibiotic resistant bacteria within and between animal production farms and from farms to residential settings. Results Enterococci from the digestive tract of house flies (n = 162), and feces of German cockroaches (n = 83) and pigs (n = 119), collected from two commercial swine farms were isolated, quantified, identified, and screened for antibiotic resistance and virulence. The majority of samples (93.7%) were positive for enterococci with concentrations 4.2 0.7 104 CFU/house fly, 5.5 1.1 106 CFU/g of cockroach feces, and 3.2 0.8 105 CFU/g of pig feces. Among all the identified isolates (n = 639) Enterococcus faecalis was the most common (55.5%), followed by E. hirae (24.9%), E. faecium (12.8%), and E. casseliflavus (6.7%). E. faecalis was most prevalent in house flies and cockroaches, and E. hirae was most common in pig feces. Our data showed that multi-drug (mainly tetracycline and erythromycin) resistant enterococci were common from all three sources and frequently carried antibiotic resistance genes including tet(M) and erm(B) and Tn916/1545 transposon family. E. faecalis frequently harbored virulence factors gelE, esp, and asa1. PFGE analysis of selected E. faecalis and E. faecium isolates demonstrated that cockroaches and house flies shared some of the same enterococcal clones that were detected in the swine manure indicating that insects acquired enterococci from swine manure. Conclusions This study shows that house flies and German cockroaches in the confined swine production environment likely serve as vectors and/or reservoirs of antibiotic resistant and potentially virulent enterococci and consequently may play an important role in animal and public health. PMID:21269466

  5. 25 CFR 900.220 - Does it make a difference whether the claim is large or small?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Does it make a difference whether the claim is large or small? 900.220 Section 900.220 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR, AND INDIAN... EDUCATION ASSISTANCE ACT Post-Award Contract Disputes § 900.220 Does it make a difference whether the...

  6. Examination of Sex Differences in a Large Sample of Young Children with Autism Spectrum Disorder and Typical Development

    ERIC Educational Resources Information Center

    Reinhardt, Vanessa P.; Wetherby, Amy M.; Schatschneider, Christopher; Lord, Catherine

    2015-01-01

    Despite consistent and substantive research documenting a large male to female ratio in Autism Spectrum Disorder (ASD), only a modest body of research exists examining sex differences in characteristics. This study examined sex differences in developmental functioning and early social communication in children with ASD as compared to children with…

  7. Examination of Sex Differences in a Large Sample of Young Children with Autism Spectrum Disorder and Typical Development

    ERIC Educational Resources Information Center

    Reinhardt, Vanessa P.; Wetherby, Amy M.; Schatschneider, Christopher; Lord, Catherine

    2015-01-01

    Despite consistent and substantive research documenting a large male to female ratio in Autism Spectrum Disorder (ASD), only a modest body of research exists examining sex differences in characteristics. This study examined sex differences in developmental functioning and early social communication in children with ASD as compared to children with

  8. Hydrodynamic modeling of juvenile mussel dispersal in a large river: The potential effects of bed shear stress and other parameters

    USGS Publications Warehouse

    Daraio, J.A.; Weber, L.J.; Newton, T.J.

    2010-01-01

    Because unionid mussels have a parasitic larval stage, they are able to disperse upstream and downstream as larvae while attached to their host fish and with flow as juveniles after excystment from the host. Understanding unionid population ecology requires knowledge of the processes that affect juvenile dispersal prior to establishment. We examined presettlement (transport and dispersion with flow) and early postsettlement (bed shear stress) hydraulic processes as negative censoring mechanisms. Our approach was to model dispersal using particle tracking through a 3-dimensional flow field output from hydrodynamic models of a reach of the Upper Mississippi River. We tested the potential effects of bed shear stress (??b) at 5 flow rates on juvenile mussel dispersal and quantified the magnitude of these effects as a function of flow rate. We explored the reach-scale relationships of Froude number (Fr), water depth (H), local bed slope (S), and unit stream power (QS) with the likelihood of juvenile settling (??). We ran multiple dispersal simulations at each flow rate to estimate ??, the parameter of a Poisson distribution, from the number of juveniles settling in each grid cell, and calculated dispersal distances. Virtual juveniles that settled in areas of the river where b > critical shear stress (c) were resuspended in the flow and transported further downstream, so we ran simulations at 3 different conditions for ??c (??c = ??? no resuspension, 0.1, and 0.05 N/m2). Differences in virtual juvenile dispersal distance were significantly dependent upon c and flow rate, and effects of b on settling distribution were dependent upon c. Most simulations resulted in positive correlations between ?? and ??b, results suggesting that during early postsettlement, ??b might be the primary determinant of juvenile settling distribution. Negative correlations between ?? and ??b occurred in some simulations, a result suggesting that physical or biological presettlement processes might determine juvenile settling distributions. Field data are needed to test these hypotheses. Results support the idea that flow patterns and b can act as negative censoring mechanisms controlling settling distributions. Furthermore, a river reach probably has a quantifiable threshold range of flow rates. Above the upper threshold, ??b probably is the primary determinant of juvenile settling distribution. Relationships of ?? with H, Fr, S, and QS were relatively weak. Important physical processes that affect dispersal probably are not captured by approximations based on large-scale hydraulic parameters, such as Fr and H. ?? 2010 The North American Benthological Society.

  9. Potential vertical movement of large heat-generating waste packages in salt.

    SciTech Connect

    Clayton, Daniel James; Martinez, Mario J.; Hardin, Ernest L.

    2013-05-01

    With renewed interest in disposal of heat-generating waste in bedded or domal salt formations, scoping analyses were conducted to estimate rates of waste package vertical movement. Vertical movement is found to result from thermal expansion, from upward creep or heave of the near-field salt, and from downward buoyant forces on the waste package. A two-pronged analysis approach was used, with thermal-mechanical creep modeling, and coupled thermal-viscous flow modeling. The thermal-mechanical approach used well-studied salt constitutive models, while the thermal-viscous approach represented the salt as a highly viscous fluid. The Sierra suite of coupled simulation codes was used for both approaches. The waste package in all simulations was a right-circular cylinder with the density of steel, in horizontal orientation. A time-decaying heat generation function was used to represent commercial spent fuel with typical burnup and 50-year age. Results from the thermal-mechanical base case showed approximately 27 cm initial uplift of the package, followed by gradual relaxation closely following the calculated temperature history. A similar displacement history was obtained with the package density set equal to that of salt. The slight difference in these runs is attributable to buoyant displacement (sinking) and is on the order of 1 mm in 2,000 years. Without heat generation the displacement stabilizes at a fraction of millimeter after a few hundred years. Results from thermal-viscous model were similar, except that the rate of sinking was constant after cooldown, at approximately 0.15 mm per 1,000 yr. In summary, all calculations showed vertical movement on the order of 1 mm or less in 2,000 yr, including calculations using well-established constitutive models for temperature-dependent salt deformation. Based on this finding, displacement of waste packages in a salt repository is not a significant repository performance issue.

  10. Potential Mechanisms for Racial and Ethnic Differences in Antimüllerian Hormone and Ovarian Reserve

    PubMed Central

    Seifer, David B.

    2013-01-01

    Accumulating evidence suggests that reproductive potential and function may be different across racial and ethnic groups. Racial differences have been demonstrated in pubertal timing, infertility, outcomes after assisted reproductive technology (ART) treatment, and reproductive aging. Recently, racial differences have also been described in serum antimüllerian hormone (AMH), a sensitive biomarker of ovarian reserve, supporting the notion that ovarian reserve differs between racial/ethnic groups. The existence of such racial/ethnic differences in ovarian reserve, as reflected by AMH, may have important clinical implications for reproductive endocrinologists. However, the mechanisms which may underlie such racial differences in ovarian reserve are unclear. Various genetic factors and environmental factors such as obesity, smoking, and vitamin D deficiency which have been shown to correlate with serum AMH levels and also display significant racial/ethnic variations are discussed in this review. Improving our understanding of racial differences in ovarian reserve and their underlying causes may be essential for infertility treatment in minority women and lead to better reproductive planning, improved treatment outcomes, and timely interventions which may prolong reproductive lifespan in these women. PMID:24348557

  11. Sex Differences in Autism Spectrum Disorder: Evidence from a Large Sample of Children and Adolescents

    ERIC Educational Resources Information Center

    Mandy, William; Chilvers, Rebecca; Chowdhury, Uttom; Salter, Gemma; Seigal, Anna; Skuse, David

    2012-01-01

    Sex differences have been found amongst toddlers and young children with autism spectrum disorder (ASD). We investigated the presence and stability of these ASD sex differences throughout childhood and adolescence. Participants (N = 325, 52 females; aged 3-18 years) consecutively received an ASD diagnosis at a clinic for assessing high-functioning

  12. Sex Differences in Autism Spectrum Disorder: Evidence from a Large Sample of Children and Adolescents

    ERIC Educational Resources Information Center

    Mandy, William; Chilvers, Rebecca; Chowdhury, Uttom; Salter, Gemma; Seigal, Anna; Skuse, David

    2012-01-01

    Sex differences have been found amongst toddlers and young children with autism spectrum disorder (ASD). We investigated the presence and stability of these ASD sex differences throughout childhood and adolescence. Participants (N = 325, 52 females; aged 3-18 years) consecutively received an ASD diagnosis at a clinic for assessing high-functioning…

  13. Allocation of attention during pursuit of large objects is no different than during fixation

    PubMed Central

    Watamaniuk, Scott N. J.; Heinen, Stephen J.

    2015-01-01

    Attention allocation during pursuit of a spot is usually characterized as asymmetric with more attention placed ahead of the target than behind it. However, attention is symmetrically allocated across larger pursuit stimuli. An unresolved issue is how tightly attention is constrained on large stimuli during pursuit. Although some work shows it is tightly locked to the fovea, other work shows it is allocated flexibly. To investigate this, we had observers perform a character identification task on large pursuit stimuli composed of arrays of five, nine, or 15 characters spaced between 0.6° and 4.0° apart. Initially, the characters were identical, but at a random time, they all changed briefly, rendering one of them unique. Observers identified the unique character. Consistent with previous literature, attention appeared narrow and symmetric around the pursuit target for tightly spaced (0.6°) characters. Increasing spacing dramatically expanded the attention scope, presumably by mitigating crowding. However, when we controlled for crowding, performance was limited by set size, suffering more for eccentric targets. Interestingly, the same limitations on attention allocation were observed with stationary and pursued stimuli—evidence that attention operates similarly during fixation and pursuit of a stimulus that extends into the periphery. The results suggest that attention is flexibly allocated during pursuit, but performance is limited by crowding and set size. In addition, performing the identification task did not hurt pursuit performance, further evidence that pursuit of large stimuli is relatively inattentive. PMID:26200890

  14. Large-scale synthesis, characterization and microwave absorption properties of carbon nanotubes of different helicities

    SciTech Connect

    Qi Xiaosi; Yang Yi; Zhong Wei; Deng Yu; Au Chaktong; Du Youwei

    2009-10-15

    Carbon nanotubes of high helicity (H-HCNTs, Sample A) have been synthesized in large-scale by pyrolysis of acetylene at 450 deg. C over Fe nanoparticles derived from coprecipitation/hydrogen reduction method. With controlled introduction of hydrogen during acetylene pyrolysis, CNTs of low helicity (L-HCNTs, Sample B) and worm-like CNTs (Sample C) were obtained in large quantities. The yields of the CNTs products are high, especially that of H-HCNTs (ca. 7474%). The complex permittivity and permeability of Composites A, B, and C that contain Samples A, B and C (30 wt%) were measured in the 2-18 GHz frequency range. Good absorption of electromagnetic wave (reflection loss<-20 dB) was observed in the 7.18-10.68 and 7.5-10.7 GHz range over Composites B and C (2.0-3.0 mm thickness), respectively. Thus, through the suggested route, CNTs can be produced easily and selectively in large quantities. The lightweight materials can be utilized for microwave absorption. - Graphical abstract: FESEM image of Sample B and reflection loss versus frequency of Composite B (containing 30 wt% of Sample B) in the range of 2-18 GHz.

  15. Assessment of different colour parameters for discriminating potential suspended sediment sources and provenance: A multi-scale study in Luxembourg

    NASA Astrophysics Data System (ADS)

    Martnez-Carreras, Nria; Krein, Andreas; Gallart, Francesc; Iffly, Jean F.; Pfister, Laurent; Hoffmann, Lucien; Owens, Philip N.

    2010-05-01

    Sediment colour has recently been used successfully to estimate suspended sediment sources in small catchments using the fingerprinting approach. The methodology offers opportunity for further research since it provides a rapid and cheap means for investigating sediment sources. However, the colour-based fingerprinting approach has not yet been tested in medium and large catchments. This paper aims to test whether colour parameters are capable of discriminating sediment sources in a nested system of seven sub-catchments ranging from 0.7 to 247 km 2 of the Attert River catchment, NW Luxembourg. Time-integrated suspended sediment samples and samples of potential sediment sources (land-use types and channel banks) were collected in all catchments. Sediment colour was then computed from diffuse reflectance spectrometry measurements (ASD FieldSpec-II spectrometer, 0.4-2.5 m) taken over the visible wavelength range. Twenty-four colour parameters were derived from several colour space models (CIE xyY, CIE XYZ, RGB, Munsell HVC, Helmholtz chromaticity, CIELUV and CIELAB) and their ability to discriminate potential suspended sediment sources and provenance was evaluated and compared. Results demonstrated that time-integrated suspended sediment samples collected in the study catchments had statistically different colour values. Moreover, these values always represented a mixture of the colour values measured on potential suspended sediment sources in the catchment. Inter-source colour contrasts (land-use types and channel banks) were observed in all catchments (Kruskal-Wallis H-test). However, although colour is able to distinguish potential sediment sources in small catchments, the level of source discrimination decreases as the catchment size increases, probably due to heterogeneous geology and pedology, intra-source variability and to source overlap. Nevertheless, in the studied medium-sized catchments (ranging from 19.4 to 247 km 2), colour could differentiate between topsoil and sub-surface (i.e. channel bank) material and/or up to three sources types. No single colour model had discrimination power across catchments, instead in each catchment a different combination of colour parameters gathered from different colour space models produced optimal discrimination of potential sediment sources. Furthermore, a colour-based fingerprinting approach did not possess potential for integrating spatial provenance and source type information because colour parameters could not discriminate between contrasting geological sub-areas. In summary, although colour parameters were not capable of discriminating the range of land-use type and channel banks as potential suspended sediment sources in medium-sized catchments, they afford substantial information and could be integrated into the classical fingerprinting approach together with other constituents (e.g. geochemistry, radionuclides and/or organic compounds).

  16. Utilizing Focus Groups with Potential Participants and Their Parents: An Approach to Inform Study Design in a Large Clinical Trial

    PubMed Central

    Kadimpati, Sandeep; McCormick, Jennifer B; Chiu, Yichen; Parker, Ashley B.; Iftikhar, Aliya Z.; Flick, Randall P.; Warner, David O.

    2014-01-01

    Background In the recent literature, there has been some evidence that exposure of children to anesthetic procedures during the first two years of life may impair cognitive function and learning in later life. We planned a clinical study to quantify this risk, a study involving testing 1,000 children for neurodevelopmental deficits. As a part of this planning, we conducted focus groups involving potential participants and their parents to elicit information regarding three issues: communications with the community and potential participants, recruitment and consent processes, and the return of neurodevelopmental testing results. Methods Three focus groups were conducted with the parents of potential participants and one focus group was conducted with an 18-19 year old group; each group consisted of 6-10 participants. The moderated discussions had questions about recruitment, consenting issues, and expectations from the study about return of both overall trial findings and individual research test results. Results The focus group data gave us an insight on potential participants views on recruitment, consenting, communications about the study, and expectations about return of both overall trial findings and individual research test results. The concerns expressed were largely addressable. In addition, the concern we had about some parents enrolling their children in the study solely for the sake of getting their child's cognitive function results was dispelled. Conclusions We found that the individuals participating in our focus groups were generally enthusiastic about the large clinical study and could see the value in answering the study question. The data from the focus groups were used to inform changes to the recruitment and consent process. Focus group input was also instrumental in affirming the study design regarding return of results. Our experience suggests that the approach we used may serve as a model for other investigators to help inform the various elements of clinical study design, in particular the recruitment and consenting processes and expectations of potential participants regarding the return of individual research findings. PMID:24955380

  17. Analysis of 6Li Scattering at 240 MeV Using Different Nuclear Potentials

    NASA Astrophysics Data System (ADS)

    Al-Ghamdi, A. H.; Ibraheem, Awad A.

    2016-03-01

    Angular distributions of the elastic and inelastic scattering cross sections of 6Li projectile on different heavy ion target nuclei including the 24Mg, 28Si, 48Ca, 58Ni, 90Zr, and 116Sn at energy of 240 MeV have been analyzed by using two different folded potentials based on the CDM3Y6 and São Paulo potentials for the real part of the optical potential, while the imaginary parts have a phenomenological Woods-Saxon shape. Coupled channel calculations for the low-lying 2+ state at 1.369, 1.779, 3.832, 1.454, 2.186, and 1.29 MeV for 24Mg, 28Si, 48Ca, 58Ni, 90Zr, and 116Sn, respectively, have been carried out, and the best fit values for B(EL) with the above models have been extracted by fitting the inelastic scattering cross section and compared with the values of previous works. The total reaction cross section and real and imaginary volume integrals have also been investigated.

  18. Environmental assessment of two different crop systems in terms of biomethane potential production.

    PubMed

    Bacenetti, Jacopo; Fusi, Alessandra; Negri, Marco; Guidetti, Riccardo; Fiala, Marco

    2014-01-01

    The interest in renewable energy sources has gained great importance in Europe due to the need to reduce fossil energy consumption and greenhouse gas emissions, as required by the Renewable Energy Directive (RED) of the European Parliament. The production of energy from energy crops appears to be consistent with RED. The environmental impact related to this kind of energy primarily originates from crop cultivation. This research aimed to evaluate the environmental impact of different crop systems for biomass production: single and double crop. The environmental performances of maize and maize plus wheat were assessed from a life cycle perspective. Two alternative scenarios considering different yields, crop management, and climatic conditions, were also addressed. One normal cubic metre of potential methane was chosen as a functional unit. Methane potential production data were obtained through lab experimental tests. For both of the crop systems, the factors that have the greatest influence on the overall environmental burden are: fertilizer emissions, diesel fuel emissions, diesel fuel production, and pesticide production. Notwithstanding the greater level of methane potential production, the double crop system appears to have the worse environmental performance with respect to its single crop counterpart. This result is due to the bigger quantity of inputs needed for the double crop system. Therefore, the greater amount of biomass (silage) obtained through the double crop system is less than proportional to the environmental burden that results from the bigger quantity of inputs requested for double crop. PMID:23994820

  19. Paranormal psychic believers and skeptics: a large-scale test of the cognitive differences hypothesis.

    PubMed

    Gray, Stephen J; Gallo, David A

    2016-02-01

    Belief in paranormal psychic phenomena is widespread in the United States, with over a third of the population believing in extrasensory perception (ESP). Why do some people believe, while others are skeptical? According to the cognitive differences hypothesis, individual differences in the way people process information about the world can contribute to the creation of psychic beliefs, such as differences in memory accuracy (e.g., selectively remembering a fortune teller's correct predictions) or analytical thinking (e.g., relying on intuition rather than scrutinizing evidence). While this hypothesis is prevalent in the literature, few have attempted to empirically test it. Here, we provided the most comprehensive test of the cognitive differences hypothesis to date. In 3 studies, we used online screening to recruit groups of strong believers and strong skeptics, matched on key demographics (age, sex, and years of education). These groups were then tested in laboratory and online settings using multiple cognitive tasks and other measures. Our cognitive testing showed that there were no consistent group differences on tasks of episodic memory distortion, autobiographical memory distortion, or working memory capacity, but skeptics consistently outperformed believers on several tasks tapping analytical or logical thinking as well as vocabulary. These findings demonstrate cognitive similarities and differences between these groups and suggest that differences in analytical thinking and conceptual knowledge might contribute to the development of psychic beliefs. We also found that psychic belief was associated with greater life satisfaction, demonstrating benefits associated with psychic beliefs and highlighting the role of both cognitive and noncognitive factors in understanding these individual differences. PMID:26503412

  20. Myoelectric activity along human gastrocnemius medialis: Different spatial distributions of postural and electrically elicited surface potentials

    PubMed Central

    Hodson-Tole, Emma F.; Loram, Ian D.; Vieira, Taian M.M.

    2013-01-01

    It has recently been shown that motor units in human medial gastrocnemius (MG), activated during standing, occupy relatively small territories along the muscles longitudinal axis. Such organisation provides potential for different motor tasks to produce differing regional patterns of activity. Here, we investigate whether postural control and nerve electrical stimulation produce equal longitudinal activation patterns in MG. Myoelectric activity, at different proximaldistal locations of MG, was recorded using a linear electrode array. To ensure differences in signal amplitude between channels did not result from local, morphological factors two experimental protocols were completed: (i) quiet standing; (ii) electrical stimulation of the tibial nerve. Averaged, rectified values (ARVs) were calculated for each channel in each condition. The distribution of signals along electrode channels was described using linear regression and differences between protocols at each channel determined as the ratio between mean ARV from standing: stimulation protocols. Ratio values changed systematically across electrode channels in seven (of eight) participants, with larger values in distal channels. The distribution of ARV along MG therefore differed between experimental conditions. Compared to fibres of units activated during MG nerve stimulation, units activated during standing may have a tendency to be more highly represented in the distal muscle portion. PMID:22967836

  1. Different involvement of extracellular matrix components in small and large arteries during chronic NO synthase inhibition.

    PubMed

    Bouvet, Cline; Gilbert, Liz-Ann; Girardot, Daphn; deBlois, Denis; Moreau, Pierre

    2005-03-01

    In essential hypertension, conduit arteries present hypertrophic remodeling (increased cross-sectional area), whereas small arteries undergo eutrophic remodeling. The involvement of matrix metalloproteinases (MMPs) and de-adhesion proteins, such as tenascin-C and thrombospondin, has been relatively well characterized in large artery remodeling, but their contribution is not known in small artery remodeling. Rats received N(omega)-nitro-L-arginine methyl ester (L-NAME; 50 mg/kg per day) in their drinking water on days 1, 3, 7, 14, and 28. Arterial MMP-2 activity was measured by ELISA, whereas levels of tenascin-C and thrombospondin were assessed by Western blotting. To determine the involvement of MMPs, additional L-NAME rats received the nonselective MMP inhibitor doxycycline (30 mg/kg per day) on days 7, 14, and 28. Already, at day 1, pressure was elevated. Media/lumen ratio of mesenteric arteries and the aorta increased gradually to reach significance at 28 days. However, the cross-sectional area increased only in the aorta, confirming the heterogeneous remodeling process. In small arteries, MMP-2 activity increased after 7 and 14 days of treatment and returned to baseline at 28 days, whereas the elevation was more progressive but sustained in the aorta. The level of thrombospondin paralleled that of MMP-2 in small arteries, whereas tenascin-C levels declined rapidly and stayed below control values. Doxycycline blunted large artery remodeling but had no influence on the development of eutrophic remodeling despite elevation of MMP-2 activity in the process. Thus, in contrast to large artery hypertrophic remodeling, in which the contributions of cellular de-adhesion and matrix breakdown is manifest, the contribution of MMPs in eutrophic remodeling appears less crucial. PMID:15655118

  2. Evaluation of the mutagenic potential of different forms of energy production.

    PubMed

    Lonard, A; Lonard, E D

    1983-08-01

    The consequence of exposure to the effluents of power plants that elicits the most concern is probably the induction of cancers. Due mainly to the high uncertainty of epidemiological surveys on exposure to low doses of mutagens, observations performed up to now on man have provided contradictory and inconclusive results. Since a high correlation exists between the mutagenicity of environmental agents and their carcinogenic properties, an attempt has been made to evaluate the carcinogenic potential of the different forms of energy production on the basis of the results of short term tests performed on the effluents of several power plants. Any energy source is associated with such risks and, in spite of the fact that real comparative studies were not available, coal as a source of energy presents obviously higher mutagenic potential than nuclear power. Renewable forms of energy are cleaner but are, however, not entirely devoid of health impacts. PMID:6356352

  3. Plant community response to loss of large herbivores differs between North American and South African savanna grasslands.

    PubMed

    Koerner, Sally E; Burkepile, Deron E; Fynn, Richard W S; Burns, Catherine E; Eby, Stephanie; Govender, Navashni; Hagenah, Nicole; Matchett, Katherine J; Thompson, Dave I; Wilcox, Kevin R; Collins, Scott L; Kirkman, Kevin P; Knapp, Alan K; Smith, Melinda D

    2014-04-01

    Herbivory and fire shape plant community structure in grass-dominated ecosystems, but these disturbance regimes are being altered around the world. To assess the consequences of such alterations, we excluded large herbivores for seven years from mesic savanna grasslands sites burned at different frequencies in North America (Konza Prairie Biological Station, Kansas, USA) and South Africa (Kruger National Park). We hypothesized that the removal of a single grass-feeding herbivore from Konza would decrease plant community richness and shift community composition due to increased dominance by grasses. Similarly, we expected grass dominance to increase at Kruger when removing large herbivores, but because large herbivores are more diverse, targeting both grasses and forbs, at this study site, the changes due to herbivore removal would be muted. After seven years of large-herbivore exclusion, richness strongly decreased and community composition changed at Konza, whereas little change was evident at Kruger. We found that this divergence in response was largely due to differences in the traits and numbers of dominant grasses between the study sites rather than the predicted differences in herbivore assemblages. Thus, the diversity of large herbivores lost may be less important in determining plant community dynamics than the functional traits of the grasses that dominate mesic, disturbance-maintained savanna grasslands. PMID:24933802

  4. Phenotypic identification of subclones in multiple myeloma with different chemoresistant, cytogenetic and clonogenic potential.

    PubMed

    Pano, T; Paiva, B; Sayagus, J M; Mota, I; Carvalheiro, T; Corchete, L A; Aires-Meja, I; Prez, J J; Sanchez, M L; Barcena, P; Ocio, E M; San-Segundo, L; Sarasquete, M E; Garca-Sanz, R; Vidriales, M-B; Oriol, A; Hernndez, M-T; Echeveste, M-A; Paiva, A; Blade, J; Lahuerta, J-J; Orfao, A; Mateos, M-V; Gutirrez, N C; San-Miguel, J F

    2015-05-01

    Knowledge about clonal diversity and selection is critical to understand multiple myeloma (MM) pathogenesis, chemoresistance and progression. If targeted therapy becomes reality, identification and monitoring of intraclonal plasma cell (PC) heterogeneity would become increasingly demanded. Here we investigated the kinetics of intraclonal heterogeneity among 116 MM patients using 23-marker multidimensional flow cytometry (MFC) and principal component analysis, at diagnosis and during minimal residual disease (MRD) monitoring. Distinct phenotypic subclones were observed in 35/116 (30%) newly diagnosed MM patients. In 10/35 patients, persistent MRD was detected after 9 induction cycles, and longitudinal comparison of patient-paired diagnostic vs MRD samples unraveled phenotypic clonal tiding after therapy in half (5/10) of the patients. After demonstrating selection of distinct phenotypic subsets by therapeutic pressure, we investigated whether distinct fluorescence-activated cell-sorted PC subclones had different clonogenic and cytogenetic profiles. In half (5/10) of the patients analyzed, distinct phenotypic subclones showed different clonogenic potential when co-cultured with stromal cells, and in 6/11 cases distinct phenotypic subclones displayed unique cytogenetic profiles by interphase fluorescence in situ hybridization, including selective del(17p13). Collectively, we unravel potential therapeutic selection of preexisting diagnostic phenotypic subclones during MRD monitoring; because phenotypically distinct PCs may show different clonogenic and cytogenetic profiles, identification and follow-up of unique phenotypic-genetic myeloma PC subclones may become relevant for tailored therapy. PMID:25388955

  5. Comparing large scale CCS deployment potential in the USA and China: a detailed analysis based on country-specific CO2 transport & storage cost curves

    SciTech Connect

    Dahowski, Robert T.; Davidson, Casie L.; Dooley, James J.

    2011-04-18

    The United States and China are the two largest emitters of greenhouse gases in the world and their projected continued growth and reliance on fossil fuels, especially coal, make them strong candidates for CCS. Previous work has revealed that both nations have over 1600 large electric utility and other industrial point CO2 sources as well as very large CO2 storage resources on the order of 2,000 billion metric tons (Gt) of onshore storage capacity. In each case, the vast majority of this capacity is found in deep saline formations. In both the USA and China, candidate storage reservoirs are likely to be accessible by most sources with over 80% of these large industrial CO2 sources having a CO2 storage option within just 80 km. This suggests a strong potential for CCS deployment as a meaningful option to efforts to reduce CO2 emissions from these large, vibrant economies. However, while the USA and China possess many similarities with regards to the potential value that CCS might provide, including the range of costs at which CCS may be available to most large CO2 sources in each nation, there are a number of more subtle differences that may help us to understand the ways in which CCS deployment may differ between these two countries in order for the USA and China to work together - and in step with the rest of the world - to most efficiently reduce greenhouse gas emissions. This paper details the first ever analysis of CCS deployment costs in these two countries based on methodologically comparable CO2 source and sink inventories, economic analysis, geospatial source-sink matching and cost curve modeling. This type of analysis provides a valuable insight into the degree to which early and sustained opportunities for climate change mitigation via commercial-scale CCS are available to the two countries, and could facilitate greater collaboration in areas where those opportunities overlap.

  6. Cross-polar cap potential difference, auroral electrojet indices, and solar wind parameters

    SciTech Connect

    Ahn, B.H. Univ. of Colorado, Boulder ); Kamide, Y. ); Kroehl, H.W.; Gorney, D.J. )

    1992-02-01

    The cross-polar cap potential difference {Phi} (KRM) is estimated from ground magnetic perturbation data through the magnetometer inversion method of Kamide, Richmond, and Matsushita (FRM), combined with an empirical ionospheric conductance distribution estimated from the DMSP X ray image data. A significant correlation is found between {Phi} (KRM) and the AE(12) index. {Phi} (KRM) is then compared with the potential difference estimated from a more direct method of the satellite electric field measurements and also with {Phi}(IMF) is found to be linearly correlated with {Phi} (IMF) based on solar wind parameters. {Phi} IMF is found to be linearly correlated with {Phi}(KRM), as {Phi}(IMF) = 29.8 + 0.999 {Phi} (KRM), with the highest correlation obtained for a 40-min lag in the interplanetary magnetic field (IMF). Note that {Phi}(IMF) is systematically larger than {Phi} (KRM) by 30 kV, suggesting the possibility that the theoretical method overestimates the cross-polar cap potential difference. During steady southward IMF periods were steady {Phi} (IMF) variations are expected, significant fluctuations in calculated {Phi} (KRM) values are obtained. Since the decrease in {Phi} (KRM) is closely associated with enhancements in auroral particle precipitation during these periods, a highly correlative relation between {Phi} (IMF) and {Phi} (KRM) cannot be deduced unless the phases of substorms are taken into account. The overall high correlation between them, however, supports the view expressed by Wolf et al. (1986) that directly driven processes are more important than unloading processes during disturbed periods.

  7. What causes the difference in synergistic potentials of propiconazole and prochloraz toward pyrethroids in Daphnia magna?

    PubMed

    Dalhoff, Kristoffer; Gottardi, Michele; Kretschmann, Andreas; Cedergreen, Nina

    2016-03-01

    Azole fungicides (imidazoles and triazoles) are known to function synergistically with several compounds, especially with pyrethroid insecticides, most likely by inhibiting cytochrome P450. Different azole fungicides have been shown to differ in their synergistic potentials usually with the imidazoles being stronger synergists than the triazoles. This study investigated whether the toxicokinetic and toxicodynamic (TKTD) properties of the imidazole prochloraz and triazole propiconazole can explain their different synergistic potential toward the freshwater macroinvertebrate Daphnia magna. Pulse exposure to external concentrations of propiconazole (1.4μM) and prochloraz (1.7μM) for 18h resulted in internal concentrations of 22.7 and 53.5μmolkg(-1)w.w. for propiconazole and prochloraz, respectively. This 2-fold difference in bioaccumulation corresponded very well with the observed 2.7-fold lower external EC50-estimate (7 days) for prochloraz compared to propiconazole. The estimated IC50 for the in vivo inhibition of cytochrome P450 (ECOD) activity, however, measured as transformation of 7-ethoxycoumarin into 7-hydroxycoumarin, was almost 500-fold higher for prochloraz (IC50: 0.011±0.002μM) compared to propiconazole (IC50: 4.9±0.06μM). When indirectly measuring the binding strength of the two azoles, daphnids exposed to propiconazole recovered roughly 80% of their ECOD activity compared to the control shortly after being moved to azole-free medium, indicating that propiconazole causes reversible inhibition of cytochrome P450. In contrast, the ECOD-activity remained inhibited in the prochloraz-exposed daphnids for 12h following transfer to azole-free medium, which correlated with elimination of the measured internal prochloraz concentration (DT95≈13h). These results indicate that lethal toxicity of the azole fungicides is mainly driven by toxicokinetics through their hydrophobicities resulting in different internal concentrations. Their synergistic potential toward pyrethroid toxicity, on the other hand, is mainly governed by their toxicodynamic effects measured as the differences in IC50-values toward in vivo cytochrome P450 (ECOD) activity together with the proposed binding strength measured indirectly through the recovery of ECOD activity as a function of internal azole concentrations. PMID:26784738

  8. Shock-induced plasticity in tantalum single crystals: Interatomic potentials and large-scale molecular-dynamics simulations

    NASA Astrophysics Data System (ADS)

    Ravelo, R.; Germann, T. C.; Guerrero, O.; An, Q.; Holian, B. L.

    2013-10-01

    We report on large-scale nonequilibrium molecular dynamics simulations of shock wave compression in tantalum single crystals. Two new embedded atom method interatomic potentials of Ta have been developed and optimized by fitting to experimental and density functional theory data. The potentials reproduce the isothermal equation of state of Ta up to 300 GPa. We examined the nature of the plastic deformation and elastic limits as functions of crystal orientation. Shock waves along (100), (110), and (111) exhibit elastic-plastic two-wave structures. Plastic deformation in shock compression along (110) is due primarily to the formation of twins that nucleate at the shock front. The strain-rate dependence of the flow stress is found to be orientation dependent, with (110) shocks exhibiting the weaker dependence. Premelting at a temperature much below that of thermodynamic melting at the shock front is observed in all three directions for shock pressures above about 180 GPa.

  9. Phytoremediation potential of cadmium-contaminated soil by Eucalyptus globulus under different coppice systems.

    PubMed

    Luo, Jie; Qi, Shihua; Peng, Li; Xie, Xianming

    2015-03-01

    The objective of this research was to determine the phytoremediation potential of Eucalyptus globulus in Cd contaminated soil through two different harvest methods. Although replanting is more expensive than coppicing and produces less aboveground biomass, more Cd can be removed from the soil with roots removal at each harvest as the E. globulus absorbs vast majority of heavy metals in non-metabolically active parts like roots. Despite the higher cost of replanting in a single harvest, when phytoremediation efficiency and total duration are considered as important factors, the replanting treatment should be recommended as an appropriate method which can decrease the phytoremediation time obviously. PMID:25543544

  10. Differences in Electrostatic Potential Around DNA Fragments Containing Guanine and 8-oxo-Guanine

    SciTech Connect

    Haranczyk, Maciej; Gutowski, Maciej S.

    2007-02-01

    hanges of electrostatic potential (EP) around the DNA molecule resulting from chemical modifications of nucleotides may play a role in enzymatic recognition of damaged sites. Effects of chemical modifications of nucleotides on the structure of DNA have been characterized through large scale density functional theory computations. Quantum mechanical structural optimizations of DNA fragments with three pairs of nucleotoides and accompanying counteractions were performed with a B3LYP exchange-correlation functional and 6-31G** basis sets. The intact DNA fragment contained guanine in the middle layer, while the damaged fragment had the guanine replaced with 8-oxo-guanine. The electrostatic potential around these DNA fragments was projected on a surface around the double helix. The 2D maps of EP of intact and damaged DNA fragments were analyzed to identify these modifications of EP that result from the occurrence of 8-oxo-guanine. It was found that distortions of the phosphate groups and displacements of the accompanying countercations are clearly reflected in the EP maps.

  11. Assessing climate change induced modification of Penman potential evaporation and runoff sensitivity in a large water-limited basin

    NASA Astrophysics Data System (ADS)

    Liu, Qiang; McVicar, Tim R.

    2012-09-01

    SummaryPotential evaporation (Ep) reflects the combined effects of four key meteorological variables: (i) net radiation (Rn); (ii) wind speed (u); (iii) relative humidity (rh); and (iv) air temperature (Ta). Here, attribution analysis was conducted to investigate the contribution of the four key meteorological variables to changes of a physically-based Ep in a large water-limited basin, the Yellow River Basin (YRB), China. Then the influences of these changes, and precipitation (P) changes, on streamflow (Q) were explored analytically. Results show that: (i) Ep presented different temporal trends for the water yielding region (WYR) and water consuming region (WCR) with a overall changes of +0.16 mm a-2 and -0.66 mm a-2 during 1961-2010, respectively; (ii) trend analysis of Ep and the four key meteorological variables at the basin scale showed that increasing trend in Ta increased Ep during 1961-2010, while changes in Rn and u increased the 1961-1979 Ep rate and reduced it during 1980-1994 and 1995-2010; (iii) revealed by attribution analysis, Ep increased by changes in Ta and rh and reduced by changes of Rn and u in both WYR and WCR, in all, Ep rate presented positive and negative trends in the WYR and WCR, respectively; (iv) the changes of Q and actual evaporation (E) are much more sensitive to changes in P than the changes in Ep; and (v) of critical importance for water resource management of the YRB changes in Q are mainly attributed to changes in catchment-specific parameter (n) and P, while Ep reduced Q in WYR and increased Q in WCR. These results indicated that the causes of trend of Ep rates, influenced by combined effects of radiative and aerodynamic variables should be explicitly explained using fully physically based Ep formulations. Additionally, in the water-limited YRB, changes of Q are primarily controlled by the changes in catchment conditions, and secondarily by hydroclimatic factors where the available water (P) rather than energy condition (Ep) is more important. Better understanding all of these relationships and how they have varied will help water resource management in a changing climate.

  12. Who Gets Market Supplements? Gender Differences within a Large Canadian University

    ERIC Educational Resources Information Center

    Doucet, Christine; Durand, Claire; Smith, Michael

    2008-01-01

    This study examines the gender pay gap among university faculty by analyzing gender differences in one component of faculty members' salaries--"market premiums." The data were collected during the Fall of 2002 using a survey of faculty at a single Canadian research university. Correspondence analysis and logistic regression analysis were performed…

  13. Gender Differences in Achievement in a Large, Nationally Representative Sample of Children and Adolescents

    ERIC Educational Resources Information Center

    Scheiber, Caroline; Reynolds, Matthew R.; Hajovsky, Daniel B.; Kaufman, Alan S.

    2015-01-01

    The purpose of this study was to investigate developmental gender differences in academic achievement areas, with the primary focus on writing, using the child and adolescent portion (ages 6-21 years) of the "Kaufman Test of Educational Achievement-Second Edition, Brief Form," norming sample (N = 1,574). Path analytic models with gender,

  14. [Temperature compensation strategy and implementation for photoelectric modulation interferometer with large optical path difference].

    PubMed

    Wang, Yan-Chao; Wang, Zhi-Bin; Zhang, Ji-Long; Chen, You-Hua

    2013-05-01

    For temperature drift in hypervelocity photoelectric modulation interferometer, a control model of temperature compensation is presented including voltage and phase compensation. First, according to the similar and modeling theory, an equivalent circuit model of mechanical properties of hypervelocity photoelectric modulation interferometer was established, the impact of temperature drift on its resonance frequency was analyzed, a mathematical model was set up, which contains drive voltage, frequency and resonance frequency, and the control method was determined for high optical path difference to get steady. Then, a digital method including voltage and phase compensation is given for optical path difference deviation control, which merges the DPLL and program of voltage and phase compensation. Finally, the control method was tested through experiment system. A test between drive control system including voltage and phase compensation and traditional drive control system was executed, using a laser doppler vibrometer to record the amount of change in optical path difference within 3 hours. Results show that the optical path difference deviation caused by temperature drift in long term is reduced by about 50%. PMID:23905367

  15. Gender Differences in Achievement in a Large, Nationally Representative Sample of Children and Adolescents

    ERIC Educational Resources Information Center

    Scheiber, Caroline; Reynolds, Matthew R.; Hajovsky, Daniel B.; Kaufman, Alan S.

    2015-01-01

    The purpose of this study was to investigate developmental gender differences in academic achievement areas, with the primary focus on writing, using the child and adolescent portion (ages 6-21 years) of the "Kaufman Test of Educational Achievement-Second Edition, Brief Form," norming sample (N = 1,574). Path analytic models with gender,…

  16. Drug solubility in luminal fluids from different regions of the small and large intestine of humans.

    PubMed

    Fadda, H M; Sousa, T; Carlsson, A S; Abrahamsson, B; Williams, J G; Kumar, D; Basit, A W

    2010-10-01

    The purpose of this work was to study the solubility of two drugs with different physicochemical properties in luminal fluids obtained from various regions of the human gastrointestinal (GI) tract and to determine the most important luminal parameters influencing their solubility. Jejunal fluids were aspirated from healthy volunteers via an oral intubation tube. Ileal and colonic fluids were obtained from patients undergoing GI surgery. Stoma fluids were also retrieved from patients. pH and buffer capacity of all fluids were determined. Saturation solubility of prednisolone (unionisable) and mesalamine (5-aminosalicylic acid) (zwitterionic) was measured. Mean solubility of prednisolone in the different luminal fluids was 0.50 mg/mL (±0.05) and did not vary significantly between the different regions of the GI tract (ANOVA, p > 0.05). No correlation between prednisolone solubility and jejunal bile salt content was found. Mesalamine solubility increased down the GI tract: 1.97 (±0.25), 3.26 (±0.08), 6.24 (±1.13) and 7.95 (±0.21) mg/mL in jejunal, ileal, ascending and transverse/descending colonic fluids respectively. Buffer capacity also increased and in one patient was observed to range from 6.4 to 28.6 reaching 44.4 mM/L/pH unit in ileal, ascending and transverse/descending colon fluids respectively. Mesalamine solubility was found to be dependent on both buffer capacity and pH, with buffer capacity being the most important (standardized coefficient β = 0.849, p < 0.0001) compared to pH (β = 0.219, p < 0.05). For drugs delivered as modified release formulations it is important to consider solubility in different regions of the GI tract as significant differences can arise which will ultimately influence drug bioavailability. PMID:20726533

  17. Oxidative potential of secondary organic aerosols produced from photooxidation of different hydrocarbons using outdoor chamber under ambient sunlight

    NASA Astrophysics Data System (ADS)

    Jiang, Huanhuan; Jang, Myoseon; Sabo-Attwood, Tara; Robinson, Sarah E.

    2016-04-01

    The oxidative potential of various secondary organic aerosols (SOA) was measured using dithiothreitol (DTT) assay to understand how organic aerosols react with cellular materials. SOA was produced via the photooxidation of four different hydrocarbons (toluene, 1,3,5-trimethylbenzene, isoprene and α-pinene) in the presence of NOx using a large outdoor photochemical smog chamber. The DTT consumption rate was normalized by the aerosol mass, which is expressed as DTTmass. Toluene SOA and isoprene SOA yielded higher DTTmass than 1,3,5-trimethylbenzene SOA or α-pinene SOA. In order to discover the correlation between the molecular structure and oxidative potential, the DTT responses of selected model compounds were also measured. Among them, conjugated aldehydes, quinones, and H2O2 showed considerable DTT response. To investigate the correlation between DTT response and cell responses in vitro, the expression of biological markers, i.e. IL-6, IL-8, and HMOX-1 were studied using small airway epithelial cells. Higher cellular expression of IL-8 was observed with toluene SOA exposure compared to 1,3,5-trimethylbenzene SOA exposure, which aligned with the results from DTT assay. Our study also suggests that within the urban atmosphere, the contribution of toluene SOA and isoprene SOA to the oxidative potential of ambient SOA will be more significant than that of α-pinene SOA.

  18. College grade point average as a personnel selection device: ethnic group differences and potential adverse impact.

    PubMed

    Roth, P L; Bobko, P

    2000-06-01

    College grade point average (GPA) is often used in a variety of ways in personnel selection. Unfortunately, there is little empirical research literature in human resource management that informs researchers or practitioners about the magnitude of ethnic group differences and any potential adverse impact implications when using cumulative GPA for selection. Data from a medium-sized university in the Southeast (N = 7,498) indicate that the standardized average Black-White difference for cumulative GPA in the senior year is d = 0.78. The authors also conducted analyses at 3 GPA screens (3.00, 3.25, and 3.50) to demonstrate that employers (or educators) might face adverse impact at all 3 levels if GPA continues to be implemented as part of a selection system. Implications and future research are discussed. PMID:10900814

  19. Apollo 14 regolith breccias - Different glass populations and their potential for charting space time variations

    NASA Technical Reports Server (NTRS)

    Delano, John W.

    1988-01-01

    Apollo 14 regolith breccias (14313, 14307, 14301, 14049, 14047) have been found to have different populations of nonagglutinitic, mare-derived glasses. These variations appear to not only reflect different source regoliths but also different closure ages for these breccias. Based upon these different glass populations, 14301 is inferred to have a closure age sometime during the epoch of mare volcanism. All of the other four breccias were formed after the termination of mare volcanism with a possible age sequence from old to young of the following: 14307, 14313, 14049, 14047. Due to the relative simplicity of acquiring high-quality chemical data on large numbers of glasses by electron microprobe, mare glass populations allow: (1) classification of regolith breccias with respect to provenance and (2) estimation of their relative and absolute closure ages. The determination of (Ar-40)-(Ar-39) ages on individual glass spherules within breccias using the laser probe should in the future prove to be a promising extension of the present study.

  20. Investigation of potential waste material insulating properties at different temperature for thermal storage application

    NASA Astrophysics Data System (ADS)

    Ali, T. Z. S.; Rosli, A. B.; Gan, L. M.; Billy, A. S.; Farid, Z.

    2013-12-01

    Thermal energy storage system (TES) is developed to extend the operation of power generation. TES system is a key component in a solar energy power generation plant, but the main issue in designing the TES system is its thermal capacity of storage materials, e.g. insulator. This study is focusing on the potential waste material acts as an insulator for thermal energy storage applications. As the insulator is used to absorb heat, it is needed to find suitable material for energy conversion and at the same time reduce the waste generation. Thus, a small-scale experimental testing of natural cooling process of an insulated tank within a confined room is conducted. The experiment is repeated by changing the insulator from the potential waste material and also by changing the heat transfer fluid (HTF). The analysis presented the relationship between heat loss and the reserved period by the insulator. The results show the percentage of period of the insulated tank withstands compared to tank insulated by foam, e.g. newspaper reserved the period of 84.6% as much as foam insulated tank to withstand the heat transfer of cooking oil to the surrounding. The paper finally justifies the most potential waste material as an insulator for different temperature range of heat transfer fluid.

  1. Estimating Sugarcane Yield Potential Using an In-Season Determination of Normalized Difference Vegetative Index

    PubMed Central

    Lofton, Josh; Tubana, Brenda S.; Kanke, Yumiko; Teboh, Jasper; Viator, Howard; Dalen, Marilyn

    2012-01-01

    Estimating crop yield using remote sensing techniques has proven to be successful. However, sugarcane possesses unique characteristics; such as, a multi-year cropping cycle and plant height-limiting for midseason fertilizer application timing. Our study objective was to determine if sugarcane yield potential could be estimated using an in-season estimation of normalized difference vegetative index (NDVI). Sensor readings were taken using the GreenSeeker handheld sensor from 2008 to 2011 in St. Gabriel and Jeanerette, LA, USA. In-season estimates of yield (INSEY) values were calculated by dividing NDVI by thermal variables. Optimum timing for estimating sugarcane yield was between 601750 GDD. In-season estimated yield values improved the yield potential (YP) model compared to using NDVI. Generally, INSEY value showed a positive exponential relationship with yield (r2 values 0.48 and 0.42 for cane tonnage and sugar yield, respectively). When models were separated based on canopy structure there was an increase the strength of the relationship for the erectophile varieties (r2 0.53 and 0.47 for cane tonnage and sugar yield, respectively); however, the model for planophile varieties weakened slightly. Results of this study indicate using an INSEY value for predicting sugarcane yield shows potential of being a valuable management tool for sugarcane producers in Louisiana. PMID:22969359

  2. Large Thermal Conductivity Differences between the Crystalline and Vitrified States of DMSO with Applications to Cryopreservation.

    PubMed

    Ehrlich, Lili E; Feig, Justin S G; Schiffres, Scott N; Malen, Jonathan A; Rabin, Yoed

    2015-01-01

    Thermal conductivity of dimethyl-sulfoxide (DMSO) solution is measured in this study using a transient hot wire technique, where DMSO is a key ingredient in many cryoprotective agent (CPA) cocktails. Characterization of thermal properties of cryoprotective agents is essential to the analysis of cryopreservation processes, either when evaluating experimental data or for the design of new protocols. Also presented are reference measurements of thermal conductivity for pure water ice and glycerol. The thermal conductivity measurement setup is integrated into the experimentation stage of a scanning cryomacroscope apparatus, which facilitates the correlation of measured data with visualization of physical events. Thermal conductivity measurements were conducted for a DMSO concentration range of 2M and 10M, in a temperature range of -180C and 25C. Vitrified samples showed decreased thermal conductivity with decreasing temperature, while crystalline samples showed increased thermal conductivity with decreasing temperature. These different behaviors result in up to a tenfold difference in thermal conductivity at -180C. Such dramatic differences can drastically impact heat transfer during cryopreservation and their quantification is therefore critical to cryobiology. PMID:25985058

  3. Drag reduction in large wind turbines through riblets: evaluation of different geometries

    NASA Astrophysics Data System (ADS)

    Arndt, Roger; Chamorro, Leonardo; Sotiropoulos, Fotis

    2011-11-01

    Achieving skin friction drag reduction by use of riblets has been a topic of intensive research throughout the last several decades. The majority of the effort on this topic has been based on both numerical (mainly DNS) and experimental (wind tunnel and fluid channel) approaches. Yet, despite these valuable endeavors, the fundamental mechanisms that induce the drag reduction are still not well established. In this study, wind tunnel experiments were performed to quantify the drag reduction for a wind turbine airfoil caused by different V-grooved riblet configurations. A full-scale 2.5MW Clipper wind turbine airfoil section (of 1 meter chord length, typical of the 88% blade span) was placed in the freestream flow of the wind tunnel at the Saint Anthony Falls Laboratory, University of Minnesota. The drag forces the airfoil experienced were measured for different riblet configurations and at different angles of attack, all with a constant Reynolds number of Re=2.2 millions (based on the airfoil chord length). Layouts of both complete and partial airfoil coverage, of riblets, were considered in the study. Force sensors were used to measure Lift and Drag but more accurate Drag forces were obtained through wake surveys using a pitot static probe. The measurements will be used to help develop and test the performance of near-wall boundary conditions in the context of RANS and hybrid RANS/LES models.

  4. Large Thermal Conductivity Differences between the Crystalline and Vitrified States of DMSO with Applications to Cryopreservation

    PubMed Central

    Ehrlich, Lili E.; Feig, Justin S. G.; Schiffres, Scott N.; Malen, Jonathan A.; Rabin, Yoed

    2015-01-01

    Thermal conductivity of dimethyl-sulfoxide (DMSO) solution is measured in this study using a transient hot wire technique, where DMSO is a key ingredient in many cryoprotective agent (CPA) cocktails. Characterization of thermal properties of cryoprotective agents is essential to the analysis of cryopreservation processes, either when evaluating experimental data or for the design of new protocols. Also presented are reference measurements of thermal conductivity for pure water ice and glycerol. The thermal conductivity measurement setup is integrated into the experimentation stage of a scanning cryomacroscope apparatus, which facilitates the correlation of measured data with visualization of physical events. Thermal conductivity measurements were conducted for a DMSO concentration range of 2M and 10M, in a temperature range of -180C and 25C. Vitrified samples showed decreased thermal conductivity with decreasing temperature, while crystalline samples showed increased thermal conductivity with decreasing temperature. These different behaviors result in up to a tenfold difference in thermal conductivity at -180C. Such dramatic differences can drastically impact heat transfer during cryopreservation and their quantification is therefore critical to cryobiology. PMID:25985058

  5. Theoretical study of the origin of the large difference in the visible absorption spectra of organic dyes containing a thienylmethine unit and differing by the methine unit position

    NASA Astrophysics Data System (ADS)

    Manzhos, Sergei; Komatsu, Makoto; Nakazaki, Jotaro; Segawa, Hiroshi; Yamashita, Koichi

    2011-10-01

    We analyze the origin of the large (about 128 nm) difference in the maximum of the visible absorption spectrum of dyes 2-Cyano-3-[5'-(4''-(N,N-dimethylamino) phenyl) thiophen-2'-yl] acrylic acid and Cyano-[5-(4-(N,Ndimethyl-amino) benzylidene)-5H-thiophen -2-ylidene]-acetic acid which differ by the position of the methine unit that was observed in an acetonitrile solution. We perform an ab initio analysis of possible factors such as (non-)planarity of the molecule, isomerization, and solvent effects as well as of the influence of computational parameters. Ground state calculations failed to account for the difference in transition energies, but excited state optimization of deprotonated dyes in solution resulted in values comparable to the experiment. We conclude that the most likely explanation for the difference is different stabilization of the LUMO by the polar solvent.

  6. Symbiotic potential and survival of native rhizobia kept on different carriers

    PubMed Central

    Ruíz-Valdiviezo, Víctor Manuel; Canseco, Lucía María Cristina Ventura; Suárez, Luis Antonio Castillo; Gutiérrez-Miceli, Federico Antonio; Dendooven, Luc; Rincón-Rosales, Reiner

    2015-01-01

    Native rhizobia are ideal for use as commercial legume inoculants. The characteristics of the carrier used to store the inoculants are important for the survival and symbiotic potential of the rhizobia. The objective of this study was to investigate the effects of peat (PEAT), perlite sugarcane bagasse (PSB), carboxymethyl cellulose plus starch (CMCS), and yeast extract mannitol supplemented with mannitol (YEMM) on the survival, nodulation potential and N2 fixation capacity of the native strains Sinorhizobium mexicanum ITTG R7T and Rhizobium calliandrae LBP2-1T and of the reference strain Rhizobium etli CFN42T. A factorial design (4 × 3) with four repetitions was used to determine the symbiotic potential of the rhizobial strains. The survival of the strains was higher for PEAT (46% for strain LBP2-1T, 167% for strain CFN42T and 219% for strain ITTG R7T) than for the other carriers after 240 days, except for CFN42T kept on CMCS (225%). All the strains kept on the different carriers effectively nodulated common bean, with the lowest number of nodules found (5 nodules) when CFN42T was kept on CMCS and with the highest number of nodules found (28 nodules) when ITTG R7T was kept on PSB. The nitrogenase activity was the highest for ITTG R7T kept on PEAT (4911 μmol C2H4 per fresh weight nodule h−1); however, no activity was found when the strains were kept on YEMM. Thus, the survival and symbiotic potential of the rhizobia depended on the carrier used to store them. PMID:26413054

  7. Symbiotic potential and survival of native rhizobia kept on different carriers.

    PubMed

    Ruíz-Valdiviezo, Víctor Manuel; Canseco, Lucía María Cristina Ventura; Suárez, Luis Antonio Castillo; Gutiérrez-Miceli, Federico Antonio; Dendooven, Luc; Rincón-Rosales, Reiner

    2015-01-01

    Native rhizobia are ideal for use as commercial legume inoculants. The characteristics of the carrier used to store the inoculants are important for the survival and symbiotic potential of the rhizobia. The objective of this study was to investigate the effects of peat (PEAT), perlite sugarcane bagasse (PSB), carboxymethyl cellulose plus starch (CMCS), and yeast extract mannitol supplemented with mannitol (YEMM) on the survival, nodulation potential and N2 fixation capacity of the native strains Sinorhizobium mexicanum ITTG R7(T) and Rhizobium calliandrae LBP2-1(T) and of the reference strain Rhizobium etli CFN42(T). A factorial design (4 × 3) with four repetitions was used to determine the symbiotic potential of the rhizobial strains. The survival of the strains was higher for PEAT (46% for strain LBP2-1(T), 167% for strain CFN42(T) and 219% for strain ITTG R7(T)) than for the other carriers after 240 days, except for CFN42(T) kept on CMCS (225%). All the strains kept on the different carriers effectively nodulated common bean, with the lowest number of nodules found (5 nodules) when CFN42(T) was kept on CMCS and with the highest number of nodules found (28 nodules) when ITTG R7(T) was kept on PSB. The nitrogenase activity was the highest for ITTG R7(T) kept on PEAT (4911 μmol C2H4 per fresh weight nodule h(-1)); however, no activity was found when the strains were kept on YEMM. Thus, the survival and symbiotic potential of the rhizobia depended on the carrier used to store them. PMID:26413054

  8. CARD-FISH analysis of a TCE-dechlorinating biocathode operated at different set potentials.

    PubMed

    Di Battista, Antonella; Verdini, Roberta; Rossetti, Simona; Pietrangeli, Biancamaria; Majone, Mauro; Aulenta, Federico

    2012-11-15

    Bioelectrochemical systems (BES) are increasingly being considered for bioremediation applications, such as the reductive transformation of chlorinated hydrocarbons in subsurface environments. These systems typically rely on a polarized solid-state electrode (i.e. a cathode) serving as electron donor for the microbially catalyzed reductive dechlorination of chlorinated contaminants. The microorganisms involved in dechlorinating biocathodes are not still identified. Particularly, it is not clear whether the same microorganisms responsible for the reductive dechlorination in 'conventional' bioremediation systems (i.e. those based on the supply of soluble substrates as electron donors) also play a role in BES. Here, we analyzed by CARD-FISH, the microbial composition of a dechlorinating biocathode operated at different set potential, in the range from -250 mV to -750 mV (vs. the standard hydrogen electrode, SHE). The rate and extent of TCE dechlorination, as well as of competing metabolisms (i.e. methanogenesis), were found to increase as the cathode potential decreased. The higher metabolic activities observed at the more reducing cathode potentials were mirrored by a higher total biomass concentration (as DAPI-stained cells) in the cathode effluent. CARD-FISH analysis revealed that Dehalococcoides was the dominant dechlorinating bacterial genus (from 65% to 100% of Bacteria) in the range from -550 mV to -750 mV, whereas it was abruptly outcompeted by other (yet unidentified) members of the Chloroflexi phylum, when the cathode was controlled in the range from -250 mV to -450 mV. Most probably, the observed changes in the microbial composition of the biocathode were driven by changes in the dominant mechanisms of electron transfer to TCE: mediated by the electrolytic production of H(2) gas (in the range from -550 mV to -750 mV), or direct (in the range of cathode potentials from -250 mV to -450 mV). PMID:22728722

  9. The mechanism of reduction of the ubiquinone pool in photosynthetic bacteria at different redox potentials.

    PubMed

    de Grooth, B G; van Grondelle, R; Romijn, J C; Pulles, M P

    1978-09-01

    (1) A flash number dependency of flash-induced absorbance changes was observed with whole cells of Rhodospirillum rubrum and chromatophores of R. rubrum and Rhodopseudomonas sphaeroides wild type and the G1C mutant. The oscillatory behavior was dependent on the redox potential; it was observed under oxidizing conditions only. Absorbance difference spectra measured after each flash in the 275--500 nm wavelength region showed that a molecule of ubiquinone, R, is reduced to the semiquinone (R-) after odd-numbered flashes and reoxidized after even-numbered flashes. The amount of R reduced was approximately one molecule per reaction center. (2) The flash number dependency of the electrochromic shift of the carotenoid spectrum was studied with chromatophores of Rps. sphaeroides wild type and the G1C mutant. At higher values of the ambient redox potential a relatively slow phase with a rise time of 30 ms was observed after even-numbered flashes, in addition to the fast phase (completed within 0.2 ms) occurring after each flash. Evidence was obtained that the slow phase represents the formation of an additional membrane potential during a dark reaction that occurs after flashes with an even number. This reaction is inhibited by antimycin A, whereas the oscillations of the R/R- absorbance changes remain unaffected. At low potentials (E = 100 mV) no oscillations of the carotenoid shift were observed: a fast phase was followed by a slow phase (antimycin-sensitive) with a half-time of 3 ms after each flash. (3) The results are discussed in terms of a model for the cyclic electron flow as described by Prince and Dutton (Prince, R.C. and Dutton, P.L. (1976) Bacterial Photosynthesis Conference, Brussels, Belgium, September 6--9, Abstr. TB4) employing the so-called Q-cycle. PMID:99172

  10. Establishment of rat hepatocellular carcinoma cell lines with differing metastatic potential in nude mice.

    PubMed

    Ogawa, K; Nakanishi, H; Takeshita, F; Futakuchi, M; Asamoto, M; Imaida, K; Tatematsu, M; Shirai, T

    2001-03-15

    For better understanding of cancer metastasis, we have established an in vivo model for induction of highly metastatic hepatocellular carcinomas (HCC) in male F344 rats. From 1 tumor, 4 cell lines with differing metastatic potential (C1, C2, C6, C5F) were established by subcloning using the limited-dilution cloning technique. Two other lines, N1 and L2, arose from another primary HCC and a lung metastatic lesion, respectively. Although cell adhesion of each cell line in culture medium was different, tumors developing in the subcutis of nude mice after transplantation were all moderately differentiated HCC with a trabecular pattern. On subcutaneous injection into nude mice, all 6 cell lines proved to be tumorigenic in the injection site and C5F was highly metastatic to the lung. With injection into the tail vein, N1 and L2 formed frequent metastases in the lung as well as in lymph nodes. Using intraperitoneal injection, C1, C6, N1 and L2 showed marked disseminated growth in the abdominal cavity with bloody ascitis. Northern blot analysis revealed expression of known metastasis-related genes, KAI1 and heparanase, to be decreased in C5F, but no differences in expression of nm23-H1 were evident. A point mutation in the GSK-3beta phosphorylation site of the beta-catenin gene was found in L2. These transplantable HCC cell lines that have different metastatic ability should be useful for elucidation of mechanisms of metastasis. PMID:11275982

  11. Uncertainty of SWAT model at different DEM resolutions in a large mountainous watershed.

    PubMed

    Zhang, Peipei; Liu, Ruimin; Bao, Yimeng; Wang, Jiawei; Yu, Wenwen; Shen, Zhenyao

    2014-04-15

    The objective of this study was to enhance understanding of the sensitivity of the SWAT model to the resolutions of Digital Elevation Models (DEMs) based on the analysis of multiple evaluation indicators. The Xiangxi River, a large tributary of Three Gorges Reservoir in China, was selected as the study area. A range of 17 DEM spatial resolutions, from 30 to 1000 m, was examined, and the annual and monthly model outputs based on each resolution were compared. The following results were obtained: (i) sediment yield was greatly affected by DEM resolution; (ii) the prediction of dissolved oxygen load was significantly affected by DEM resolutions coarser than 500 m; (iii) Total Nitrogen (TN) load was not greatly affected by the DEM resolution; (iv) Nitrate Nitrogen (NO₃-N) and Total Phosphorus (TP) loads were slightly affected by the DEM resolution; and (v) flow and Ammonia Nitrogen (NH₄-N) load were essentially unaffected by the DEM resolution. The flow and dissolved oxygen load decreased more significantly in the dry season than in the wet and normal seasons. Excluding flow and dissolved oxygen, the uncertainties of the other Hydrology/Non-point Source (H/NPS) pollution indicators were greater in the wet season than in the dry and normal seasons. Considering the temporal distribution uncertainties, the optimal DEM resolutions for flow was 30-200 m, for sediment and TP was 30-100 m, for dissolved oxygen and NO₃-N was 30-300 m, for NH₄-N was 30 to 70 m and for TN was 30-150 m. PMID:24509347

  12. Differences in Human Cortical Gene Expression Match the Temporal Properties of Large-Scale Functional Networks

    PubMed Central

    Cioli, Claudia; Abdi, Hervé; Beaton, Derek; Burnod, Yves; Mesmoudi, Salma

    2014-01-01

    We explore the relationships between the cortex functional organization and genetic expression (as provided by the Allen Human Brain Atlas). Previous work suggests that functional cortical networks (resting state and task based) are organized as two large networks (differentiated by their preferred information processing mode) shaped like two rings. The first ring–Visual-Sensorimotor-Auditory (VSA)–comprises visual, auditory, somatosensory, and motor cortices that process real time world interactions. The second ring–Parieto-Temporo-Frontal (PTF)–comprises parietal, temporal, and frontal regions with networks dedicated to cognitive functions, emotions, biological needs, and internally driven rhythms. We found–with correspondence analysis–that the patterns of expression of the 938 genes most differentially expressed across the cortex organized the cortex into two sets of regions that match the two rings. We confirmed this result using discriminant correspondence analysis by showing that the genetic profiles of cortical regions can reliably predict to what ring these regions belong. We found that several of the proteins–coded by genes that most differentiate the rings–were involved in neuronal information processing such as ionic channels and neurotransmitter release. The systematic study of families of genes revealed specific proteins within families preferentially expressed in each ring. The results showed strong congruence between the preferential expression of subsets of genes, temporal properties of the proteins they code, and the preferred processing modes of the rings. Ionic channels and release-related proteins more expressed in the VSA ring favor temporal precision of fast evoked neural transmission (Sodium channels SCNA1, SCNB1 potassium channel KCNA1, calcium channel CACNA2D2, Synaptotagmin SYT2, Complexin CPLX1, Synaptobrevin VAMP1). Conversely, genes expressed in the PTF ring favor slower, sustained, or rhythmic activation (Sodium channels SCNA3, SCNB3, SCN9A potassium channels KCNF1, KCNG1) and facilitate spontaneous transmitter release (calcium channel CACNA1H, Synaptotagmins SYT5, Complexin CPLX3, and synaptobrevin VAMP2). PMID:25546015

  13. Differences in human cortical gene expression match the temporal properties of large-scale functional networks.

    PubMed

    Cioli, Claudia; Abdi, Hervé; Beaton, Derek; Burnod, Yves; Mesmoudi, Salma

    2014-01-01

    We explore the relationships between the cortex functional organization and genetic expression (as provided by the Allen Human Brain Atlas). Previous work suggests that functional cortical networks (resting state and task based) are organized as two large networks (differentiated by their preferred information processing mode) shaped like two rings. The first ring--Visual-Sensorimotor-Auditory (VSA)--comprises visual, auditory, somatosensory, and motor cortices that process real time world interactions. The second ring--Parieto-Temporo-Frontal (PTF)--comprises parietal, temporal, and frontal regions with networks dedicated to cognitive functions, emotions, biological needs, and internally driven rhythms. We found--with correspondence analysis--that the patterns of expression of the 938 genes most differentially expressed across the cortex organized the cortex into two sets of regions that match the two rings. We confirmed this result using discriminant correspondence analysis by showing that the genetic profiles of cortical regions can reliably predict to what ring these regions belong. We found that several of the proteins--coded by genes that most differentiate the rings--were involved in neuronal information processing such as ionic channels and neurotransmitter release. The systematic study of families of genes revealed specific proteins within families preferentially expressed in each ring. The results showed strong congruence between the preferential expression of subsets of genes, temporal properties of the proteins they code, and the preferred processing modes of the rings. Ionic channels and release-related proteins more expressed in the VSA ring favor temporal precision of fast evoked neural transmission (Sodium channels SCNA1, SCNB1 potassium channel KCNA1, calcium channel CACNA2D2, Synaptotagmin SYT2, Complexin CPLX1, Synaptobrevin VAMP1). Conversely, genes expressed in the PTF ring favor slower, sustained, or rhythmic activation (Sodium channels SCNA3, SCNB3, SCN9A potassium channels KCNF1, KCNG1) and facilitate spontaneous transmitter release (calcium channel CACNA1H, Synaptotagmins SYT5, Complexin CPLX3, and synaptobrevin VAMP2). PMID:25546015

  14. Regional differences in rat large intestinal crypt function in relation to dehydrating capacity in vivo

    PubMed Central

    Naftalin, R J; Zammit, P S; Pedley, K C

    1999-01-01

    Rat descending colon absorbed fluid against a large hydraulic resistance, imposed by 10% agarose (w/v) gel plugs inserted in the lumen, by raising the tonicity of the absorbate from the gel to 880 54 mosmol kg?1; the tonicity of the absorbate from 2.5% gels was 352 38 mosmol kg?1. The hypertonic absorbate generated an osmotic pressure which created a fluid tension in the crypt lumen. This was monitored as a suction tension in colonic luminal gels of 45.3 3 cmH2O with 2.5% gels and 725 145 cmH2O with 10% gels. The caecum was unable to absorb fluid against a significant hydraulic resistance.Fluorescein isothiocyanate-labelled dextran (FITC dextran; molecular mass 10000 Da) accumulated within descending colonic crypt lumens by concentration polarization. Maximal accumulation at a depth of 2040 ?m below the mucosal surface was 5.68 0.2-fold above control levels. Caecal crypts accumulated dextran to a maximum of 1.8 0.17-fold above control levels.The relationship between crypt luminal tension and suction tension of the distal colon was also demonstrated using paraffin, which occluded the crypt lumens with microscopic droplets and completely inhibited fluid absorption from high resistance luminal gels.Reduction in dietary Na+ intake raised plasma aldosterone and the capacity of the distal colon to dehydrate against a high luminal hydraulic resistance. The caecum did not respond in this way to varied Na+ intake. PMID:9831727

  15. Large difference in carbon emission burial balances between boreal and arctic lakes.

    PubMed

    Lundin, E J; Klaminder, J; Bastviken, D; Olid, C; Hansson, S V; Karlsson, J

    2015-01-01

    Lakes play an important role in the global carbon (C) cycle by burying C in sediments and emitting CO2 and CH4 to the atmosphere. The strengths and control of these fundamentally different pathways are therefore of interest when assessing the continental C balance and its response to environmental change. In this study, based on new high-resolution estimates in combination with literature data, we show that annual emission:burial ratios are generally ten times higher in boreal compared to subarctic - arctic lakes. These results suggest major differences in lake C cycling between biomes, as lakes in warmer boreal regions emit more and store relatively less C than lakes in colder arctic regions. Such effects are of major importance for understanding climatic feedbacks on the continental C sink - source function at high latitudes. If predictions of global warming and northward expansion of the boreal biome are correct, it is likely that increasing C emissions from high latitude lakes will partly counteract the presumed increasing terrestrial C sink capacity at high latitudes. PMID:26370519

  16. Large difference in carbon emission - burial balances between boreal and arctic lakes

    NASA Astrophysics Data System (ADS)

    Lundin, E. J.; Klaminder, J.; Bastviken, D.; Olid, C.; Hansson, S. V.; Karlsson, J.

    2015-09-01

    Lakes play an important role in the global carbon (C) cycle by burying C in sediments and emitting CO2 and CH4 to the atmosphere. The strengths and control of these fundamentally different pathways are therefore of interest when assessing the continental C balance and its response to environmental change. In this study, based on new high-resolution estimates in combination with literature data, we show that annual emission:burial ratios are generally ten times higher in boreal compared to subarctic - arctic lakes. These results suggest major differences in lake C cycling between biomes, as lakes in warmer boreal regions emit more and store relatively less C than lakes in colder arctic regions. Such effects are of major importance for understanding climatic feedbacks on the continental C sink - source function at high latitudes. If predictions of global warming and northward expansion of the boreal biome are correct, it is likely that increasing C emissions from high latitude lakes will partly counteract the presumed increasing terrestrial C sink capacity at high latitudes.

  17. Large difference in carbon emission – burial balances between boreal and arctic lakes

    PubMed Central

    Lundin, E. J.; Klaminder, J.; Bastviken, D.; Olid, C.; Hansson, S. V.; Karlsson, J.

    2015-01-01

    Lakes play an important role in the global carbon (C) cycle by burying C in sediments and emitting CO2 and CH4 to the atmosphere. The strengths and control of these fundamentally different pathways are therefore of interest when assessing the continental C balance and its response to environmental change. In this study, based on new high-resolution estimates in combination with literature data, we show that annual emission:burial ratios are generally ten times higher in boreal compared to subarctic – arctic lakes. These results suggest major differences in lake C cycling between biomes, as lakes in warmer boreal regions emit more and store relatively less C than lakes in colder arctic regions. Such effects are of major importance for understanding climatic feedbacks on the continental C sink – source function at high latitudes. If predictions of global warming and northward expansion of the boreal biome are correct, it is likely that increasing C emissions from high latitude lakes will partly counteract the presumed increasing terrestrial C sink capacity at high latitudes. PMID:26370519

  18. The just noticeable difference of center time and clarity index in large reverberant spaces.

    PubMed

    Martellotta, F

    2010-08-01

    Just noticeable difference (JND) values are available for most acoustical parameters currently used in practice. However, they have been determined with reference to conditions typically encountered in concert halls and in rooms for speech, covering a range of reverberation times (T) spanning from 0.5 s to 2 s. When reverberation gets longer, the relationship between measured parameters describing acoustic clarity may change significantly and subjective perception might also be different. The proposed research investigates the influence of reverberation time on JND for clarity measures taking into account three reference cases having T values varying from 2 s to 6 s. Measured B-format impulse responses were properly modified to introduce the desired changes and then auralized with two music motifs for presentation on a 4-channel playback system. Listening tests based on paired comparisons were carried out to determine subjective limens. The results proved to be independent of music motifs and showed that JND in the clarity index is almost independent of T, while JND in the center time is significantly related to T and can be assumed as the 8.5% of the reference T(S) value. PMID:20707435

  19. Isotopic Differences between Forage Consumed by a Large Herbivore in Open, Closed, and Coastal Habitats: New Evidence from a Boreal Study System.

    PubMed

    Giroux, Marie-Andre; Valiquette, liane; Tremblay, Jean-Pierre; Ct, Steeve D

    2015-01-01

    Documenting habitat-related patterns in foraging behaviour at the individual level and over large temporal scales remains challenging for large herbivores. Stable isotope analysis could represent a valuable tool to quantify habitat-related foraging behaviour at the scale of individuals and over large temporal scales in forest dwelling large herbivores living in coastal environments, because the carbon (?13C) or nitrogen (?15N) isotopic signatures of forage can differ between open and closed habitats or between terrestrial and littoral forage, respectively. Here, we examined if we could detect isotopic differences between the different assemblages of forage taxa consumed by white-tailed deer that can be found in open, closed, supralittoral, and littoral habitats. We showed that ?13C of assemblages of forage taxa were 3.0 lower in closed than in open habitats, while ?15N were 2.0 and 7.4 higher in supralittoral and littoral habitats, respectively, than in terrestrial habitats. Stable isotope analysis may represent an additional technique for ecologists interested in quantifiying the consumption of terrestrial vs. marine autotrophs. Yet, given the relative isotopic proximity and the overlap between forage from open, closed, and supralittoral habitats, the next step would be to determine the potential to estimate their contribution to herbivore diet. PMID:26559186

  20. Isotopic Differences between Forage Consumed by a Large Herbivore in Open, Closed, and Coastal Habitats: New Evidence from a Boreal Study System

    PubMed Central

    Giroux, Marie-Andrée; Valiquette, Éliane; Tremblay, Jean-Pierre; Côté, Steeve D.

    2015-01-01

    Documenting habitat-related patterns in foraging behaviour at the individual level and over large temporal scales remains challenging for large herbivores. Stable isotope analysis could represent a valuable tool to quantify habitat-related foraging behaviour at the scale of individuals and over large temporal scales in forest dwelling large herbivores living in coastal environments, because the carbon (δ13C) or nitrogen (δ15N) isotopic signatures of forage can differ between open and closed habitats or between terrestrial and littoral forage, respectively. Here, we examined if we could detect isotopic differences between the different assemblages of forage taxa consumed by white-tailed deer that can be found in open, closed, supralittoral, and littoral habitats. We showed that δ13C of assemblages of forage taxa were 3.0‰ lower in closed than in open habitats, while δ15N were 2.0‰ and 7.4‰ higher in supralittoral and littoral habitats, respectively, than in terrestrial habitats. Stable isotope analysis may represent an additional technique for ecologists interested in quantifiying the consumption of terrestrial vs. marine autotrophs. Yet, given the relative isotopic proximity and the overlap between forage from open, closed, and supralittoral habitats, the next step would be to determine the potential to estimate their contribution to herbivore diet. PMID:26559186

  1. Potential of GPS Common Clock Single-differences for Deformation Monitoring

    NASA Astrophysics Data System (ADS)

    Schön, Steffen; Pham, Hue Kiem; Kersten, Tobias; Leute, Julia; Bauch, Andreas

    2016-03-01

    Global satellite navigation systems (GNSS) are a standard measurement device for deformation monitoring. In many applications, double-differences are used to reduce distance dependent systematic effects, as well as to eliminate the receiver and satellites clock errors. However, due to the navigation principle of one way ranging used in GPS, the geometry of the subsequent adjustment is weakened. As a result, the height component is generally determined three times less precisely than the horizontal coordinates. In addition, large correlations between the height and elevation dependent effects exist such as tropospheric refraction, mismodelled phase center variations, or multipath which restricts the attainable accuracy. However, for a kinematic analysis, i. e. for estimating high rate coordinate time series, the situation can be significantly improved if a common clock is connected to different GNSS receivers in a network or on a baseline. Consequently, between-station single-differences are sufficient to solve for the baseline coordinates. The positioning geometry is significantly improved which is reflected by a reduction of the standard deviation of kinematic heights by about a factor 3 underlining the benefits of this new approach. Real data from baselines at the Physikalisch-Technische Bundesanstalt campus at Braunschweig where receivers are connected over 290 m via an optical fiber link to a common clock was analysed.

  2. Finite element-finite difference thermal/structural analysis of large space truss structures

    NASA Technical Reports Server (NTRS)

    Warren, Andrew H.; Arelt, Joseph E.; Eskew, William F.; Rogers, Karen M.

    1992-01-01

    A technique of automated and efficient thermal-structural processing of truss structures that interfaces the finite element and finite difference method was developed. The thermal-structural analysis tasks include development of the thermal and structural math models, thermal analysis, development of an interface and data transfer between the models, and finally an evaluation of the thermal stresses and displacements in the structure. Consequently, the objective of the developed technique was to minimize the model development time, in order to assure an automatic transfer of data between the thermal and structural models as well as to minimize the computer resources needed for the analysis itself. The method and techniques described are illustrated on the thermal/structural analysis of the Space Station Freedom main truss.

  3. Chromatin organization and cytological features of carnivorous Genlisea species with large genome size differences.

    PubMed

    Tran, Trung D; Cao, Hieu X; Jovtchev, Gabriele; Novák, Petr; Vu, Giang T H; Macas, Jiří; Schubert, Ingo; Fuchs, Joerg

    2015-01-01

    The monophyletic carnivorous genus Genlisea (Lentibulariaceae) is characterized by a bi-directional genome size evolution resulting in a 25-fold difference in nuclear DNA content. This is one of the largest ranges found within a genus so far and makes Genlisea an interesting subject to study mechanisms of genome and karyotype evolution. Genlisea nigrocaulis, with 86 Mbp one of the smallest plant genomes, and the 18-fold larger genome of G. hispidula (1,550 Mbp) possess identical chromosome numbers (2n = 40) but differ considerably in chromatin organization, nuclear and cell size. Interphase nuclei of G. nigrocaulis and of related species with small genomes, G. aurea (133 Mbp, 2n ≈ 104) and G. pygmaea (179 Mbp, 2n = 80), are hallmarked by intensely DAPI-stained chromocenters, carrying typical heterochromatin-associated methylation marks (5-methylcytosine, H3K9me2), while in G. hispidula and surprisingly also in the small genome of G. margaretae (184 Mbp, 2n = 38) the heterochromatin marks are more evenly distributed. Probes of tandem repetitive sequences together with rDNA allow the unequivocal discrimination of 13 out of 20 chromosome pairs of G. hispidula. One of the repetitive sequences labeled half of the chromosome set almost homogenously supporting an allopolyploid status of G. hispidula and its close relative G. subglabra (1,622 Mbp, 2n = 40). In G. nigrocaulis 11 chromosome pairs could be individualized using a combination of rDNA and unique genomic probes. The presented data provide a basis for future studies of karyotype evolution within the genus Genlisea. PMID:26347752

  4. Chromatin organization and cytological features of carnivorous Genlisea species with large genome size differences

    PubMed Central

    Tran, Trung D.; Cao, Hieu X.; Jovtchev, Gabriele; Novák, Petr; Vu, Giang T. H.; Macas, Jiří; Schubert, Ingo; Fuchs, Joerg

    2015-01-01

    The monophyletic carnivorous genus Genlisea (Lentibulariaceae) is characterized by a bi-directional genome size evolution resulting in a 25-fold difference in nuclear DNA content. This is one of the largest ranges found within a genus so far and makes Genlisea an interesting subject to study mechanisms of genome and karyotype evolution. Genlisea nigrocaulis, with 86 Mbp one of the smallest plant genomes, and the 18-fold larger genome of G. hispidula (1,550 Mbp) possess identical chromosome numbers (2n = 40) but differ considerably in chromatin organization, nuclear and cell size. Interphase nuclei of G. nigrocaulis and of related species with small genomes, G. aurea (133 Mbp, 2n ≈ 104) and G. pygmaea (179 Mbp, 2n = 80), are hallmarked by intensely DAPI-stained chromocenters, carrying typical heterochromatin-associated methylation marks (5-methylcytosine, H3K9me2), while in G. hispidula and surprisingly also in the small genome of G. margaretae (184 Mbp, 2n = 38) the heterochromatin marks are more evenly distributed. Probes of tandem repetitive sequences together with rDNA allow the unequivocal discrimination of 13 out of 20 chromosome pairs of G. hispidula. One of the repetitive sequences labeled half of the chromosome set almost homogenously supporting an allopolyploid status of G. hispidula and its close relative G. subglabra (1,622 Mbp, 2n = 40). In G. nigrocaulis 11 chromosome pairs could be individualized using a combination of rDNA and unique genomic probes. The presented data provide a basis for future studies of karyotype evolution within the genus Genlisea. PMID:26347752

  5. Flat tree-level inflationary potentials in the light of cosmic microwave background and large scale structure data

    SciTech Connect

    Ballesteros, G; Casas, J A; Espinosa, J R; Ruiz de Austri, R

    2008-03-15

    We use cosmic microwave background (CMB) and large scale structure (LSS) data to test a broad and physically well-motivated class of inflationary models: those with flat tree-level potentials (typical in supersymmetry). The non-trivial features of the potential arise from radiative corrections which give a simple logarithmic dependence on the inflaton field, making the models very predictive. We also consider a modified scenario with new physics beyond a certain high energy cut-off showing up as non-renormalizable operators (NRO) in the inflaton field. We find that both kinds of models fit CMB and LSS data remarkably well, with very few free parameters. Besides, many of these models naturally predict a reasonable number of e-folds. A robust feature of these scenarios is the smallness of tensor perturbations (r{approx}<10{sup -3}). The NRO case can give a sizable running of the spectral index while achieving a sufficient number of e-folds. We use Bayesian model comparison tools to assess the relative performance of the models. We believe that these scenarios can be considered as a standard physical class of inflationary models, on a similar footing to monomial potentials.

  6. Motor unit potential morphology differences in individuals with non-specific arm pain and lateral epicondylitis

    PubMed Central

    Calder, Kristina M; Stashuk, Daniel W; McLean, Linda

    2008-01-01

    Background The pathophysiology of non-specific arm pain (NSAP) is unclear and the diagnosis is made by excluding other specific upper limb pathologies, such as lateral epicondylitis or cervical radiculopathy. The purpose of this study was to determine: (i) if the quantitative parameters related to motor unit potential morphology and/or motor unit firing patterns derived from electromyographic (EMG) signals detected from an affected muscle of patients with NSAP are different from those detected in the same muscle of individuals with lateral epicondylitis (LE) and/or control subjects and (ii) if the quantitative EMG parameters suggest that the underlying pathophysiology in NSAP is either myopathic or neuropathic in nature. Methods Sixteen subjects with NSAP, 11 subjects with LE, eight subjects deemed to be at-risk for developing a repetitive strain injury, and 37 control subjects participated. A quantitative electromyography evaluation was completed using decomposition-based quantitative electromyography (DQEMG). Needle- and surface-detected EMG signals were collected during low-level isometric contractions of the extensor carpi radialis brevis (ECRB) muscle. DQEMG was used to extract needle-detected motor unit potential trains (MUPTs), and needle-detected motor unit potential (MUP) and surface detected motor unit potential (SMUP) morphology and motor unit (MU) firing rates were compared among the four groups using one-way analysis of variance (ANOVA). Post hoc analyses were performed using Tukey's pairwise comparisons. Results Significant group differences were found for all MUP variables and for MU firing rate (p < 0.006). The post-hoc analyses revealed that patients with NSAP had smaller MUP amplitude and SMUP amplitude and area compared to the control and LE groups (p < 0.006). MUP duration and AAR values were significantly larger in the NSAP, LE and at-risk groups compared to the control group (p < 0.006); while MUP amplitude, duration and AAR values were smaller in the NSAP compared to the LE group. SMUP duration was significantly shorter in the NSAP group compared to the control group (p < 0.006). NSAP, LE and at-risk subjects had lower mean MU firing rates than the control subjects (p < 0.006). Conclusion The size-related parameters suggest that the NSAP group had significantly smaller MUPs and SMUPs than the control and LE subjects. Smaller MUPs and SMUPs may be indicative of muscle fiber atrophy and/or loss. A prospective study is needed to confirm any causal relationship between smaller MUPs and SMUPs and NSAP as found in this work. PMID:19087309

  7. Dynamics of large landslide movement over coal mine Angren, in period of different strong distant earthquakes

    NASA Astrophysics Data System (ADS)

    Nyazov, R.; Nurtaev, B.

    2011-12-01

    In 1985, on the working coal mine Angren board began to develop landslide "Central", and another landslide "Old substation" formed in 1993. In 2001 the process of connecting these two adjacent sites has been started, and in 2011 two landslides were merged. As a result, the upper band formed graben like longitudinal down warping with width 150 m, length 1400 m and an amplitude of 0.5-2 m, volume of the landslide was 120-130 m3. Motion of the landslide mass with average thickness of 100 m occurs in a shallow surface 40 in the contact zone of limestone with fine-grained sands and greenish clays of Paleogene. Merging of landslides occurred in result of earthquake impact from Hindu Kush in March 21, 2011, M = 5.8, at depth 196 km. Intensity of motions in Angren 2-3 units and effective duration of 105 seconds. Geodetic GPS measurements carried out there since 2005, regular cycle was held March, 21 in the morning before the earthquake, after 10-12 hours the earthquake was carried out repeated measurement. There was a sharp increase in groundwater discharge, in the upper ledges of mine was formed lake 20-25 m long, 15 m wide and 1 m deep. At the bottom of the mine employees watched the water flow, which probably is connected with the vibration and deformation of the underground hydrogeological system. The rate of displacement of landslide in the day of the earthquake is not sharply increased. It began to be accelerated in the course of 57 days (21.03-17.05) in the Central zone from 168 to 749 mm / day and 79 days (21.03-8.06) in the upper zone from 68 to 385.4 mm/day. Then, the displacement velocity began to decline during the past two months to 310.8 mm/day (middle) and 255 mm / day in the upper zone. In 19.07.2011, there was a local earthquake in Kyrgyzstan, M = 6.2, H = 10-12 km, distance 135 km from Angren with intensity of 5 units, duration of horizontal vibrations 60-70 seconds. By carried out repeated GPS measurements after 12 hours, the acceleration of the displacement was noted only in one benchmark (6), located in the upper zone, where the vertical displacement increased to 431 mm/day and subsided to 2-2.5 m. The horizontal dis-placement for 5 days before the earthquake was equal to 255 mm/day, after the earthquake, 223 mm/day, i.e. this earthquake did not cause the rate change. Thus, two different earth-quakes, occurred at different times caused different effects, but activation of the landslide determines by the state of critical stability of mine board.

  8. Exploring the potential of UV-spectral luminescence on different types of stalagmites

    NASA Astrophysics Data System (ADS)

    Reichelmann, Dana F. C.; Tjallingii, Rik; Brummer, Geert-Jan A.; Fohlmeister, Jens; Schröder-Ritzrau, Andrea; Constantin, Silviu; Richter, Detlev K.; Scholz, Denis

    2015-04-01

    The application of UV- spectral luminescence scanning (UV-SLS) has become an established method to reconstruct river discharge and associated precipitation form coral records. The studies on coral cores have shown that relative variations of the green and blue intensities emitted after exposure by UV light are related with relative concentrations humic acids. We explore the potential of UV-SLS on 7 stalagmite samples originating from three caves with very different settings. Three of the selected stalagmites originate from the Cloşani Cave (Romania), two stalagmites from the Zoolithencave (Germany) and two stalagmites from the B7-Cave (Germany). All stalagmites were polished before scanning with the Avaatech core scanner at the NIOZ (Netherlands) using both UV and visual light. This scanner is equipped with a UV-LED light source and can continuously record the emitted UV-SLS with a CCD line-scan camera (~70m/pixel). Under visual light the stalagmites from Zoolithencave show fine laminations of lighter and darker brownish layers. Both samples from B7-Cave show several brownish detritus layers as well as milky parts, but also some dark/clear parts with a visible lamination. Finally, the stalagmites from Cloşani Cave are very different with one stalagmite showing alternating white and dark/clear lamination, while a second one is more or less completely clear and a third one showing brownish detritus layers as well as dark/clear and milky parts. Preliminary UV-SLS results reveal that the very clear stalagmite C09-2 from Cloşani Cave does not show any luminescence. Similarly, all brownish detritus layers in the different speleothems turn opaque, which proofs to be useful to detect hiatuses in speleothems. Furthermore, the whiter parts in the stalagmites B7-1, B7-7 (B7-Cave) and C09-1 (Cloşani Cave) show stronger luminescence than the darker/clearer parts. The stalagmite Stam-4 (Cloşani Cave) shows a clear lamination of alternating white and dark/clear layers, which also appears in the luminescence scans with more luminescence in the white than in the dark layers. The brownish layers in the speleothems from Zoolithncave show higher luminescence than the clear layers, which could be interpret as more humic acids contained in the brownish layers. These preliminary results show the potential of UV-luminescence scanning for analysing speleothems and also indicate which stalagmites may be appropriate for this type of analysis. More detailed comparison with elemental chemistry and stable isotopes is planned to further explore the potential of UV-SLS analysis of speleothems.

  9. Interannual variation in climate-potential net primary productivity relationships in differing ecosystems of California

    SciTech Connect

    Koch, G.W.; Randerson, J.T. )

    1994-06-01

    The seasonality and interannual variation in potential net primary production (NPP) were examined in differing vegetation types in California over three years of contrasting precipitation using co-registered maps of climate, vegetation, and 1km biweekly NDVI derived from high resolution satellite AVHRR data. Differences in seasonality of the vegetation types (annual grassland, chamise chaparral, deciduous oak woodland, and evergreen oak) were clearly evident and corresponded well to patterns observed in field studies. In years and locations having high precipitation the annual peak in NDVI occurred later in all vegetation classes. The annual sum of biweekly NDVI was correlated with annual precipitation in all vegetation types, although the slopes and intercepts of the regressions differed among types. Annual grassland showed the largest increase in sumNDVI per unit increase in total precipitation and most of the variation in grassland sumNDVI was explained by variation in autumn precipitation. In general the ratio of sumNDVI to annual precipitation was dependent on the temporal distribution of precipitation with respect to the long-term average pattern. Published relationships between precipitation and NPP were used to develop equations relating annual NDVI sum to NPP.

  10. Annual surveys of larval Ambystoma cingulatum reveal large differences in dates of pond residency

    SciTech Connect

    Bevelhimer, Mark S; Giffen, Neil R; Stevenson, Dirk

    2008-05-01

    Effective sampling of pond-dwelling larval stages of the federally listed Ambystoma cingulatum (Flatwoods Salamander) requires sufficient knowledge of when larvae are present and how best to sample them. Through systematic sampling with active and passive sampling techniques, we found dipnetting to be significantly more effective than three types of passive traps. During surveys for Flatwoods Salamander larvae at Fort Stewart Military Installation, GA in 2005 and 2006, we found that pond residency varied by at least 1.5 months between the 2 years due to the timing of pond filling. In addition, our latest capture on 23 May 2005 was about 2 weeks later than previously recorded at any site range-wide. A simple growth model was used to evaluate likely hatching dates based on significant rain events, observed sizes at capture, and likely growth rates. This analysis suggested that the primary dates of hatching occurred in late February 2005 and early January 2006, a difference that corresponds to that seen in the residency of the latest larval stages. A review of the survey records for Fort Stewart for the past 13 years shows a steep decline in the number of occupied ponds from near 20 to a single pond for the past two years (the only documented breeding success in a natural pond since 1999).

  11. A Large Gene Cluster Encoding Several Magnetosome Proteins Is Conserved in Different Species of Magnetotactic Bacteria

    PubMed Central

    Grnberg, Karen; Wawer, Cathrin; Tebo, Bradley M.; Schler, Dirk

    2001-01-01

    In magnetotactic bacteria, a number of specific proteins are associated with the magnetosome membrane (MM) and may have a crucial role in magnetite biomineralization. We have cloned and sequenced the genes of several of these polypeptides in the magnetotactic bacterium Magnetospirillum gryphiswaldense that could be assigned to two different genomic regions. Except for mamA, none of these genes have been previously reported to be related to magnetosome formation. Homologous genes were found in the genome sequences of M. magnetotacticum and magnetic coccus strain MC-1. The MM proteins identified display homology to tetratricopeptide repeat proteins (MamA), cation diffusion facilitators (MamB), and HtrA-like serine proteases (MamE) or bear no similarity to known proteins (MamC and MamD). A major gene cluster containing several magnetosome genes (including mamA and mamB) was found to be conserved in all three of the strains investigated. The mamAB cluster also contains additional genes that have no known homologs in any nonmagnetic organism, suggesting a specific role in magnetosome formation. PMID:11571158

  12. Influences of Different Large Mammalian Fauna on Dung Beetle Diversity in Beech Forests

    PubMed Central

    Enari, Hiroto; Koike, Shinsuke; Sakamaki, Haruka

    2013-01-01

    This paper focuses on biological relationships between mammalian species richness and the community structure of dung beetles in cool-temperate forests in the northernmost part of mainland Japan. The composition of beetle assemblages was evaluated at 3 sites in undisturbed beech forests with different mammalian fauna. In spring and summer 2009, beetles were collected at each site using pitfall traps baited with feces from Japanese macaques, Macaca fuscata Blyth (Primates: Cercopithecidae); Asiatic black bears, Ursus thibetanus Cuvier (Carnivora: Ursidae); Japanese serows, Capricornis crispus Temminck (Artiodactyla: Bovidae); and cattle. In the present study, 1,862 dung beetles representing 14 species were collected, and most dung beetles possessed the ecological characteristic of selecting specific mammalian feces. The present findings indicated that although species diversity in dung beetle assemblages was not necessarily positively correlated with mammalian species richness in cool-temperate forests, the absence of the macaque population directly resulted in the marked reduction of the beetle abundance, with the loss of the most frequent species, Aphodius eccoptus Bates (Coleoptera: Scarabaeidae) during spring. PMID:23909510

  13. Influences of different large mammalian fauna on dung beetle diversity in beech forests.

    PubMed

    Enari, Hiroto; Koike, Shinsuke; Sakamaki, Haruka

    2013-01-01

    This paper focuses on biological relationships between mammalian species richness and the community structure of dung beetles in cool-temperate forests in the northernmost part of mainland Japan. The composition of beetle assemblages was evaluated at 3 sites in undisturbed beech forests with different mammalian fauna. In spring and summer 2009, beetles were collected at each site using pitfall traps baited with feces from Japanese macaques, Macaca fuscata Blyth (Primates: Cercopithecidae); Asiatic black bears, Ursus thibetanus Cuvier (Carnivora: Ursidae); Japanese serows, Capricornis crispus Temminck (Artiodactyla: Bovidae); and cattle. In the present study, 1,862 dung beetles representing 14 species were collected, and most dung beetles possessed the ecological characteristic of selecting specific mammalian feces. The present findings indicated that although species diversity in dung beetle assemblages was not necessarily positively correlated with mammalian species richness in cool-temperate forests, the absence of the macaque population directly resulted in the marked reduction of the beetle abundance, with the loss of the most frequent species, Aphodius eccoptus Bates (Coleoptera: Scarabaeidae) during spring. PMID:23909510

  14. bZIPs and WRKYs: two large transcription factor families executing two different functional strategies

    PubMed Central

    Llorca, Carles M.; Potschin, Maren; Zentgraf, Ulrike

    2014-01-01

    bZIPs and WRKYs are two important plant transcription factor (TF) families regulating diverse developmental and stress-related processes. Since a partial overlap in these biological processes is obvious, it can be speculated that they fulfill non-redundant functions in a complex regulatory network. Here, we focus on the regulatory mechanisms that are so far described for bZIPs and WRKYs. bZIP factors need to heterodimerize for DNA-binding and regulation of transcription, and based on a bioinformatics approach, bZIPs can build up more than the double of protein interactions than WRKYs. In contrast, an enrichment of the WRKY DNA-binding motifs can be found in WRKY promoters, a phenomenon which is not observed for the bZIP family. Thus, the two TF families follow two different functional strategies in which WRKYs regulate each others transcription in a transcriptional network whereas bZIP action relies on intensive heterodimerization. PMID:24817872

  15. Low-level temperature inversions and their effect on aerosol condensation nuclei concentrations under different large-scale synoptic circulations

    NASA Astrophysics Data System (ADS)

    Li, Jun; Chen, Hongbin; Li, Zhanqing; Wang, Pucai; Cribb, Maureen; Fan, Xuehua

    2015-07-01

    Knowledge of the statistical characteristics of inversions and their effects on aerosols under different large-scale synoptic circulations is important for studying and modeling the diffusion of pollutants in the boundary layer. Based on results generated using the self-organizing map (SOM) weather classification method, this study compares the statistical characteristics of surface-based inversions (SBIs) and elevated inversions (EIs), and quantitatively evaluates the effect of SBIs on aerosol condensation nuclei (CN) concentrations and the relationship between temperature gradients and aerosols for six prevailing synoptic patterns over the the Southern Great Plains (SGP) site during 2001-10. Large-scale synoptic patterns strongly influence the statistical characteristics of inversions and the accumulation of aerosols in the low-level atmosphere. The activity, frequency, intensity, and vertical distribution of inversions are significantly different among these synoptic patterns. The vertical distribution of inversions varies diurnally and is significantly different among the different synoptic patterns. Anticyclonic patterns affect the accumulation of aerosols near the ground more strongly than cyclonic patterns. Mean aerosol CN concentrations increase during SBIs compared to no inversion cases by 16.1%, 22.6%, 24.5%, 58.7%, 29.8% and 23.7% for the six synoptic patterns. This study confirms that there is a positive correlation between temperature gradients and aerosol CN concentrations near the ground at night under similar large-scale synoptic patterns. The relationship is different for different synoptic patterns and can be described by linear functions. These findings suggest that large-scale synoptic patterns change the static stability of the atmosphere and inversions in the lower atmosphere, thereby influencing the diffusion of aerosols near the ground.

  16. Chemistry and potential mutagenicity of humic substances in waters from different watersheds in Britain and Ireland

    USGS Publications Warehouse

    Watt, B.E.; Malcolm, R.L.; Hayes, M.H.B.; Clark, N.W.E.; Chipman, J.K.

    1996-01-01

    Humic substances are amorphous organic macromolecules responsible for the hue of natural waters. They are also known to be precursors of mutagens formed on chlorination prior to distribution of drinking water. In this study humic substances from the waters of primary streams, from major rivers, and from reservoirs were isolated and fractionated into humic acids (HA), fulvic acids (FA) and XAD-4 acids using columns of XAD-8 and of XAD-4 resins in tandem, and the fractions from the different sources were chlorinated and assayed for mutagenicity. CPMAS 13C NMR spectroscopy showed marked differences in compositions not only between HA, FA, and XAD-4 acids from the same water samples, but also between the same fractions from water samples from different watersheds. There were found to be strong similarities between the fractions from watersheds which had closely related soil types. Aromaticity was greatest in HAs, and lowest in XAD-4 acids, and carboxyl contents and aliphatic character were greatest in the XAD-4 acids. Carbon content decreased in the order HA > FA > XAD-4 acids, and amino acids and neutral sugars contents decreased in the order HA > XAD-4 > FA. Titration data complemented aspects of the NMR data, demonstrating that carboxyl content decreased in the order XAD-4 acids > FA > HA, and indicated that phenolic character was highest in HAs and lowest in the XAD-4 acids. All samples tested gave rise to bacterial mutagens on chlorination. Although the mutagenicities were of the same order of magnitude for the chlorinated humic samples from the different sources, the samples which showed the greatest number of revertant bacterial colonies were from the Thames and Trent, large rivers with humic materials from diverse environments, and relatively high in amino acid contents.

  17. Hydration Differences Explain the Large Variations in the Complexation Thermodynamics of Modified ?-Cyclodextrins with Bile Salts.

    PubMed

    Khler, Jonatan; Schnbeck, Christian; Westh, Peter; Holm, Ren

    2016-01-28

    The structure and thermodynamics of inclusion complexes of seven different ?-cyclodextrins (?CDs) and three biologically relevant bile salts (BS) were investigated in the present study. Natural ?CD and six modified ?CDs [two methyl-?CDs, one sulfobutyl ether-?CD (SBE?CD), and three 2-hydroxypropyl-?CDs (HP?CD)] and their complexes with BS were investigated by isothermal titration calorimetry, NMR, and molecular dynamics simulations. With the exception of the fully methylated ?CD, which did not bind the BSs investigated, all of the ?CDs formed 1:1 complexes with the BS, and the structures were similar to those with natural ?CD; i.e., the modifications of the ?CD had limited structural impact on the formation of complexes. Isothermal titration calorimetry was carried out over in the temperature interval 5-55 C to enable the calculation of the stability constant (K) and the thermodynamic parameters enthalpy (?H), entropy (?S), and heat capacity (?Cp). The stability constants decreased with an increased degree of substitution (DS), with methyl substituents having a lower effect on the stability constant than the sulfobutyl ether and hydroxypropyl substituents on the stability constants. Enthalpy-entropy compensation was observed, since both enthalpy and entropy increased with the degree of substitution, which may reflect dehydration of the hydrophobic surface on both CD and BS. Calculations based on ?Cp data suggested that each of the substituents dehydrated 10-20 (hydroxypropyl), 22-33 (sulfobutyl ether), and 10-15 (2) (methyl) of the BS surface area, in reasonable agreement with estimates from the molecular dynamics simulations. Combined with earlier investigations on modified ?CDs, these results indicate general trends of the substituents on the thermodynamics of complex formation. PMID:26731242

  18. Benthic ammonia oxidizers differ in community structure and biogeochemical potential across a riverine delta

    PubMed Central

    Damashek, Julian; Smith, Jason M.; Mosier, Annika C.; Francis, Christopher A.

    2015-01-01

    Nitrogen pollution in coastal zones is a widespread issue, particularly in ecosystems with urban or agricultural watersheds. California's Sacramento-San Joaquin Delta, at the landward reaches of San Francisco Bay, is highly impacted by both agricultural runoff and sewage effluent, leading to chronically high nutrient loadings. In particular, the extensive discharge of ammonium into the Sacramento River has altered this ecosystem by vastly increasing ammonium concentrations and thus changing the stoichiometry of inorganic nitrogen stocks, with potential effects throughout the food web. This debate surrounding ammonium inputs highlights the importance of understanding the rates of, and controls on, nitrogen (N) cycling processes across the delta. To date, however, there has been little research examining N biogeochemistry or N-cycling microbial communities in this system. We report the first data on benthic ammonia-oxidizing microbial communities and potential nitrification rates for the Sacramento-San Joaquin Delta, focusing on the functional gene amoA (which codes for the α-subunit of ammonia monooxygenase). There were stark regional differences in ammonia-oxidizing communities, with ammonia-oxidizing bacteria (AOB) outnumbering ammonia-oxidizing archaea (AOA) only in the ammonium-rich Sacramento River. High potential nitrification rates in the Sacramento River suggested these communities may be capable of oxidizing significant amounts of ammonium, compared to the San Joaquin River and the upper reaches of San Francisco Bay. Gene diversity also showed regional patterns, as well as phylogenetically unique ammonia oxidizers in the Sacramento River. The benthic ammonia oxidizers in this nutrient-rich aquatic ecosystem may be important players in its overall nutrient cycling, and their community structure and biogeochemical function appear related to nutrient loadings. Unraveling the microbial ecology and biogeochemistry of N cycling pathways, including benthic nitrification, is a critical step toward understanding how such ecosystems respond to the changing environmental conditions wrought by human development and climate change. PMID:25620958

  19. An Application of the Difference Potentials Method to Solving External Problems in CFD

    NASA Technical Reports Server (NTRS)

    Ryaben 'Kii, Victor S.; Tsynkov, Semyon V.

    1997-01-01

    Numerical solution of infinite-domain boundary-value problems requires some special techniques that would make the problem available for treatment on the computer. Indeed, the problem must be discretized in a way that the computer operates with only finite amount of information. Therefore, the original infinite-domain formulation must be altered and/or augmented so that on one hand the solution is not changed (or changed slightly) and on the other hand the finite discrete formulation becomes available. One widely used approach to constructing such discretizations consists of truncating the unbounded original domain and then setting the artificial boundary conditions (ABC's) at the newly formed external boundary. The role of the ABC's is to close the truncated problem and at the same time to ensure that the solution found inside the finite computational domain would be maximally close to (in the ideal case, exactly the same as) the corresponding fragment of the original infinite-domain solution. Let us emphasize that the proper treatment of artificial boundaries may have a profound impact on the overall quality and performance of numerical algorithms. The latter statement is corroborated by the numerous computational experiments and especially concerns the area of CFD, in which external problems present a wide class of practically important formulations. In this paper, we review some work that has been done over the recent years on constructing highly accurate nonlocal ABC's for calculation of compressible external flows. The approach is based on implementation of the generalized potentials and pseudodifferential boundary projection operators analogous to those proposed first by Calderon. The difference potentials method (DPM) by Ryaben'kii is used for the effective computation of the generalized potentials and projections. The resulting ABC's clearly outperform the existing methods from the standpoints of accuracy and robustness, in many cases noticeably speed up the multigrid convergence, and at the same time are quite comparable to other methods from the standpoints of geometric universality and simplicity of implementation.

  20. The potential of the flora from different regions of Pakistan in phytoremediation: a review.

    PubMed

    Kamran, Muhammad Aqeel; Amna; Mufti, Rabia; Mubariz, Nadia; Syed, Jabir Hussain; Bano, Asghari; Javed, Muhammad Tariq; Munis, Muhammad Farooq Hussain; Tan, Zhiyuan; Chaudhary, Hassan Javed

    2014-01-01

    Soil and water quality is greatly affected by environmental pollution due to the increasing trend of urbanization and industrialization. In many developing countries, including Pakistan, the situation is more alarming as no preventive measures are still taken to tackle the problem. Although in developed countries, many techniques are used to remediate the environment including phytoremediation. It is the most eco-friendly technique in which plants are used to remove pollutants from the environment. Pakistan has also a great diversity of plants which could be used for the remediation of environmental pollutants. To our knowledge, few studies from Pakistan were reported about the use of flora for phytoremediation. According to recent literature, 50 plant species from Pakistan are studied for remediation purposes. In this review, the potential of different plant species for phytoremediation from Pakistan has been discussed along with their comparison to other countries to relate future perspectives. PMID:24091528

  1. Primary task event-related potentials related to different aspects of information processing

    NASA Technical Reports Server (NTRS)

    Munson, Robert C.; Horst, Richard L.; Mahaffey, David L.

    1988-01-01

    The results of two studies which investigated the relationships between cognitive processing and components of transient event-related potentials (ERPs) are presented in a task in which mental workload was manipulated. The task involved the monitoring of an array of discrete readouts for values that went out of bounds, and was somewhat analogous to tasks performed in cockpits. The ERPs elicited by the changing readouts varied with the number of readouts being monitored, the number of monitored readouts that were close to going out of bounds, and whether or not the change took a monitored readout out of bounds. Moreover, different regions of the waveform differentially reflected these effects. The results confirm the sensitivity of scalp-recorded ERPs to the cognitive processes affected by mental workload and suggest the possibility of extracting useful ERP indices of primary task performance in a wide range of man-machine settings.

  2. Differences Between Synaptic Plasticity Thresholds Result in New Timing Rules for Maximizing Long-Term Potentiation

    PubMed Central

    Lynch, Gary; Kramr, Enik A.; Babayan, Alex H.; Rumbaugh, Gavin; Gall, Christine M.

    2012-01-01

    The fundamental observation that the temporal spacing of learning episodes plays a critical role in the efficiency of memory encoding has had little effect on either research on long-term potentiation (LTP) or efforts to develop cognitive enhancers. Here we review recent findings describing a spaced trials phenomenon for LTP that appears to be related to recent evidence that plasticity thresholds differ between synapses in the adult hippocampus. Results of tests with one memory enhancing drug suggest that the compound potently facilitates LTP via effects on high threshold synapses and thus alters the temporally extended timing rules. Possible implications of these results for our understanding of LTP substrates, neurobiological contributors to the distributed practice effect, and the consequences of memory enhancement are discussed. PMID:22820276

  3. Patterns in benthic biodiversity link lake trophic status to structure and potential function of three large, deep lakes.

    PubMed

    Hayford, Barbara L; Caires, Andrea M; Chandra, Sudeep; Girdner, Scott F

    2015-01-01

    Relative to their scarcity, large, deep lakes support a large proportion of the world's freshwater species. This biodiversity is threatened by human development and is in need of conservation. Direct comparison of biodiversity is the basis of biological monitoring for conservation but is difficult to conduct between large, insular ecosystems. The objective of our study was to conduct such a comparison of benthic biodiversity between three of the world's largest lakes: Lake Tahoe, USA; Lake Hvsgl, Mongolia; and Crater Lake, USA. We examined biodiversity of common benthic organism, the non-biting midges (Chironomidae) and determined lake trophic status using chironomid-based lake typology, tested whether community structure was similar between the three lakes despite geographic distance; and tested whether chironomid diversity would show significant variation within and between lakes. Typology analysis indicated that Lake Hvsgl was ultra-oligotrophic, Crater Lake was oligotrophic, and Lake Tahoe was borderline oligotrophic/mesotrophic. These results were similar to traditional pelagic measures of lake trophic status for Lake Hvsgl and Crater Lake but differed for Lake Tahoe, which has been designated as ultra-oligotrophic by traditional pelagic measures such as transparency found in the literature. Analysis of similarity showed that Lake Tahoe and Lake Hvsgl chironomid communities were more similar to each other than either was to Crater Lake communities. Diversity varied between the three lakes and spatially within each lake. This research shows that chironomid communities from these large lakes were sensitive to trophic conditions. Chironomid communities were similar between the deep environments of Lake Hvsgl and Lake Tahoe, indicating that chironomid communities from these lakes may be useful in comparing trophic state changes in large lakes. Spatial variation in Lake Tahoe's diversity is indicative of differential response of chironomid communities to nutrient enrichment which may be an indication of changes in trophic state within and across habitats. PMID:25594516

  4. Patterns in Benthic Biodiversity Link Lake Trophic Status to Structure and Potential Function of Three Large, Deep Lakes

    PubMed Central

    Hayford, Barbara L.; Caires, Andrea M.; Chandra, Sudeep; Girdner, Scott F.

    2015-01-01

    Relative to their scarcity, large, deep lakes support a large proportion of the worlds freshwater species. This biodiversity is threatened by human development and is in need of conservation. Direct comparison of biodiversity is the basis of biological monitoring for conservation but is difficult to conduct between large, insular ecosystems. The objective of our study was to conduct such a comparison of benthic biodiversity between three of the worlds largest lakes: Lake Tahoe, USA; Lake Hvsgl, Mongolia; and Crater Lake, USA. We examined biodiversity of common benthic organism, the non-biting midges (Chironomidae) and determined lake trophic status using chironomid-based lake typology, tested whether community structure was similar between the three lakes despite geographic distance; and tested whether chironomid diversity would show significant variation within and between lakes. Typology analysis indicated that Lake Hvsgl was ultra-oligotrophic, Crater Lake was oligotrophic, and Lake Tahoe was borderline oligotrophic/mesotrophic. These results were similar to traditional pelagic measures of lake trophic status for Lake Hvsgl and Crater Lake but differed for Lake Tahoe, which has been designated as ultra-oligotrophic by traditional pelagic measures such as transparency found in the literature. Analysis of similarity showed that Lake Tahoe and Lake Hvsgl chironomid communities were more similar to each other than either was to Crater Lake communities. Diversity varied between the three lakes and spatially within each lake. This research shows that chironomid communities from these large lakes were sensitive to trophic conditions. Chironomid communities were similar between the deep environments of Lake Hvsgl and Lake Tahoe, indicating that chironomid communities from these lakes may be useful in comparing trophic state changes in large lakes. Spatial variation in Lake Tahoes diversity is indicative of differential response of chironomid communities to nutrient enrichment which may be an indication of changes in trophic state within and across habitats. PMID:25594516

  5. Organic nanoparticles from different fuel blends: in vitro toxicity and inflammatory potential.

    PubMed

    Gualtieri, Maurizio; Capasso, Laura; D'Anna, Andrea; Camatini, Marina

    2014-11-01

    Despite the well-established link between particulate vehicle emissions and adverse health effects, the biological effects produced by ultrafine particles generated from fuel combustion need to be investigated. The biological impact of nano-sized organic carbon particles in the size range 3-7 nm, obtained from an engine fuelled with a standard diesel and four diesel fuels doped with additives of commercial interest is reported. Our data showed that the number of particles < 10 nm is to a very small extent reduced by diesel particle filters, despite its ability to trap micrometric and submicrometric particulates, and that there is a correlation between the additives used and the chemical characteristics of the nanoparticles sampled. The results show that the different nano-sized organic carbon particles induce cytotoxic and proinflammatory effects on the in vitro systems A549 (epithelial cells) and BEAS-2B (bronchial cells). All the fuels tested are able to induce the release of proinflammatory interleukins 8 and 6; moreover, the IC50 values show that the additives can increase the toxic potential of particles 10 times. Further analyses are therefore needed to better define the potential impact of organic ultrafine particles on human health. PMID:25244046

  6. Comparing the Biogeochemical Potential of Hyporheic Zones Driven by Different River Morphologies

    NASA Astrophysics Data System (ADS)

    Gomez, J. D.; Harvey, J. W.

    2013-12-01

    Channel morphology controls the hydrodynamics of hyporheic exchange and its residence times. As a result, it also constrains the hyporheic zone's biogeochemical processes that transform carbon, nutrients, metals, and contaminants and the hyporheic zone's net effect at the local, reach and watershed scales. Previous studies of different morphologies (e.g., meanders, bars, and smaller bedforms such as dunes) have mainly focused on the amount of exchange or, if biogeochemistry was involved, have been specific to a particular morphology. In this work, we present a quantitative intercomparison of the amount of exchange, residence time distributions (RTDs), and biogeochemical potential for four channel morphologies: ripples, dunes, bars, and meander bends. To this end, simple two-dimensional conceptualizations and semi-analytical solutions for the hyporheic zone's flow and transport are used. In general, all morphologies are characterized by heavy-tail RTDs, implying long-term memory to solute inputs. We hypothesize that even though meander bends induce larger hyporheic exchange per unit length of channel and longer residence times, substrate limitations result in less biogeochemical processing when compared with the cumulative effect of multiple bedforms. The models presented are a function of geometric and physical properties easily measured or constrained with field or remote sensing data. The simplicity of this approach allows for practical calculations of the hyporheic zone's exchange and biogeochemical potential over a broad range of scenarios and morphologies, making it a useful tool for experimental design, sampling, and watershed scale assessment.

  7. Kinetic equivalence of transmembrane pH and electrical potential differences in ATP synthesis.

    PubMed

    Soga, Naoki; Kinosita, Kazuhiko; Yoshida, Masasuke; Suzuki, Toshiharu

    2012-03-16

    ATP synthase is the key player of Mitchell's chemiosmotic theory, converting the energy of transmembrane proton flow into the high energy bond between ADP and phosphate. The proton motive force that drives this reaction consists of two components, the pH difference (?pH) across the membrane and transmembrane electrical potential (??). The two are considered thermodynamically equivalent, but kinetic equivalence in the actual ATP synthesis is not warranted, and previous experimental results vary. Here, we show that with the thermophilic Bacillus PS3 ATP synthase that lacks an inhibitory domain of the ? subunit, ?pH imposed by acid-base transition and ?? produced by valinomycin-mediated K(+) diffusion potential contribute equally to the rate of ATP synthesis within the experimental range examined (?pH -0.3 to 2.2, ?? -30 to 140 mV, pH around the catalytic domain 8.0). Either ?pH or ?? alone can drive synthesis, even when the other slightly opposes. ?? was estimated from the Nernst equation, which appeared valid down to 1 mm K(+) inside the proteoliposomes, due to careful removal of K(+) from the lipid. PMID:22253434

  8. Betavoltaic effect in titanium dioxide nanotube arrays under build-in potential difference

    NASA Astrophysics Data System (ADS)

    Zhang, Qiang; Chen, Ranbin; San, Haisheng; Liu, Guohua; Wang, Kaiying

    2015-05-01

    We report the fabrication of sandwich-type metal/TiO2 nanotube (TNT) array/metal structures as well as their betavoltaic effects under build-in voltage through contact potential difference. The sandwiched structure is integrated by immobilized TNT arrays on Ti foil with radioisotope 63Ni planar source on Ni substrate (Ni-63Ni/TNT array/Ti). Under irradiation of the 63Ni source with activity of 8 mCi, the structure (TNT diameter ? 130 nm, length ? 11 ?m) presents optimum energy conversion efficiency of 7.30% with open-circuit voltage of 1.54 V and short-circuit current of 12.43 nA. The TNT arrays exhibit a highly potential for developing betavoltaic batteries due to its wide band gap and nanotube array configuration. The TNT-betavoltaic concept offers a facile solution for micro/nano electronics with high efficiency and long life-time instead of conventional planar junction-type batteries.

  9. Kinetic Equivalence of Transmembrane pH and Electrical Potential Differences in ATP Synthesis*

    PubMed Central

    Soga, Naoki; Kinosita, Kazuhiko; Yoshida, Masasuke; Suzuki, Toshiharu

    2012-01-01

    ATP synthase is the key player of Mitchell's chemiosmotic theory, converting the energy of transmembrane proton flow into the high energy bond between ADP and phosphate. The proton motive force that drives this reaction consists of two components, the pH difference (ΔpH) across the membrane and transmembrane electrical potential (Δψ). The two are considered thermodynamically equivalent, but kinetic equivalence in the actual ATP synthesis is not warranted, and previous experimental results vary. Here, we show that with the thermophilic Bacillus PS3 ATP synthase that lacks an inhibitory domain of the ϵ subunit, ΔpH imposed by acid-base transition and Δψ produced by valinomycin-mediated K+ diffusion potential contribute equally to the rate of ATP synthesis within the experimental range examined (ΔpH −0.3 to 2.2, Δψ −30 to 140 mV, pH around the catalytic domain 8.0). Either ΔpH or Δψ alone can drive synthesis, even when the other slightly opposes. Δψ was estimated from the Nernst equation, which appeared valid down to 1 mm K+ inside the proteoliposomes, due to careful removal of K+ from the lipid. PMID:22253434

  10. Sex Differences in Kappa Opioid Receptor Function and Their Potential Impact on Addiction.

    PubMed

    Chartoff, Elena H; Mavrikaki, Maria

    2015-01-01

    Behavioral, biological, and social sequelae that lead to drug addiction differ between men and women. Our efforts to understand addiction on a mechanistic level must include studies in both males and females. Stress, anxiety, and depression are tightly linked to addiction, and whether they precede or result from compulsive drug use depends on many factors, including biological sex. The neuropeptide dynorphin (DYN), an endogenous ligand at kappa opioid receptors (KORs), is necessary for stress-induced aversive states and is upregulated in the brain after chronic exposure to drugs of abuse. KOR agonists produce signs of anxiety, fear, and depression in laboratory animals and humans, findings that have led to the hypothesis that drug withdrawal-induced DYN release is instrumental in negative reinforcement processes that drive addiction. However, these studies were almost exclusively conducted in males. Only recently is evidence available that there are sex differences in the effects of KOR activation on affective state. This review focuses on sex differences in DYN and KOR systems and how these might contribute to sex differences in addictive behavior. Much of what is known about how biological sex influences KOR systems is from research on pain systems. The basic molecular and genetic mechanisms that have been discovered to underlie sex differences in KOR function in pain systems may apply to sex differences in KOR function in reward systems. Our goals are to discuss the current state of knowledge on how biological sex contributes to KOR function in the context of pain, mood, and addiction and to explore potential mechanisms for sex differences in KOR function. We will highlight evidence that the function of DYN-KOR systems is influenced in a sex-dependent manner by: polymorphisms in the prodynorphin (pDYN) gene, genetic linkage with the melanocortin-1 receptor (MC1R), heterodimerization of KORs and mu opioid receptors (MORs), and gonadal hormones. Finally, we identify several gaps in our understanding of "if" and "how" DYN and KORs modulate addictive behavior in a sex-dependent manner. Future work may address these gaps by building on the mechanistic studies outlined in this review. Ultimately this will enable the development of novel and effective addiction treatments tailored to either males or females. PMID:26733781

  11. Sex Differences in Kappa Opioid Receptor Function and Their Potential Impact on Addiction

    PubMed Central

    Chartoff, Elena H.; Mavrikaki, Maria

    2015-01-01

    Behavioral, biological, and social sequelae that lead to drug addiction differ between men and women. Our efforts to understand addiction on a mechanistic level must include studies in both males and females. Stress, anxiety, and depression are tightly linked to addiction, and whether they precede or result from compulsive drug use depends on many factors, including biological sex. The neuropeptide dynorphin (DYN), an endogenous ligand at kappa opioid receptors (KORs), is necessary for stress-induced aversive states and is upregulated in the brain after chronic exposure to drugs of abuse. KOR agonists produce signs of anxiety, fear, and depression in laboratory animals and humans, findings that have led to the hypothesis that drug withdrawal-induced DYN release is instrumental in negative reinforcement processes that drive addiction. However, these studies were almost exclusively conducted in males. Only recently is evidence available that there are sex differences in the effects of KOR activation on affective state. This review focuses on sex differences in DYN and KOR systems and how these might contribute to sex differences in addictive behavior. Much of what is known about how biological sex influences KOR systems is from research on pain systems. The basic molecular and genetic mechanisms that have been discovered to underlie sex differences in KOR function in pain systems may apply to sex differences in KOR function in reward systems. Our goals are to discuss the current state of knowledge on how biological sex contributes to KOR function in the context of pain, mood, and addiction and to explore potential mechanisms for sex differences in KOR function. We will highlight evidence that the function of DYN-KOR systems is influenced in a sex-dependent manner by: polymorphisms in the prodynorphin (pDYN) gene, genetic linkage with the melanocortin-1 receptor (MC1R), heterodimerization of KORs and mu opioid receptors (MORs), and gonadal hormones. Finally, we identify several gaps in our understanding of “if” and “how” DYN and KORs modulate addictive behavior in a sex-dependent manner. Future work may address these gaps by building on the mechanistic studies outlined in this review. Ultimately this will enable the development of novel and effective addiction treatments tailored to either males or females. PMID:26733781

  12. Potential Distribution Predicted for Rhynchophorus ferrugineus in China under Different Climate Warming Scenarios

    PubMed Central

    Ge, Xuezhen; He, Shanyong; Wang, Tao; Yan, Wei; Zong, Shixiang

    2015-01-01

    As the primary pest of palm trees, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) has caused serious harm to palms since it first invaded China. The present study used CLIMEX 1.1 to predict the potential distribution of R. ferrugineus in China according to both current climate data (1981–2010) and future climate warming estimates based on simulated climate data for the 2020s (2011–2040) provided by the Tyndall Center for Climate Change Research (TYN SC 2.0). Additionally, the Ecoclimatic Index (EI) values calculated for different climatic conditions (current and future, as simulated by the B2 scenario) were compared. Areas with a suitable climate for R. ferrugineus distribution were located primarily in central China according to the current climate data, with the northern boundary of the distribution reaching to 40.1°N and including Tibet, north Sichuan, central Shaanxi, south Shanxi, and east Hebei. There was little difference in the potential distribution predicted by the four emission scenarios according to future climate warming estimates. The primary prediction under future climate warming models was that, compared with the current climate model, the number of highly favorable habitats would increase significantly and expand into northern China, whereas the number of both favorable and marginally favorable habitats would decrease. Contrast analysis of EI values suggested that climate change and the density of site distribution were the main effectors of the changes in EI values. These results will help to improve control measures, prevent the spread of this pest, and revise the targeted quarantine areas. PMID:26496438

  13. Potential Distribution Predicted for Rhynchophorus ferrugineus in China under Different Climate Warming Scenarios.

    PubMed

    Ge, Xuezhen; He, Shanyong; Wang, Tao; Yan, Wei; Zong, Shixiang

    2015-01-01

    As the primary pest of palm trees, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) has caused serious harm to palms since it first invaded China. The present study used CLIMEX 1.1 to predict the potential distribution of R. ferrugineus in China according to both current climate data (1981-2010) and future climate warming estimates based on simulated climate data for the 2020s (2011-2040) provided by the Tyndall Center for Climate Change Research (TYN SC 2.0). Additionally, the Ecoclimatic Index (EI) values calculated for different climatic conditions (current and future, as simulated by the B2 scenario) were compared. Areas with a suitable climate for R. ferrugineus distribution were located primarily in central China according to the current climate data, with the northern boundary of the distribution reaching to 40.1N and including Tibet, north Sichuan, central Shaanxi, south Shanxi, and east Hebei. There was little difference in the potential distribution predicted by the four emission scenarios according to future climate warming estimates. The primary prediction under future climate warming models was that, compared with the current climate model, the number of highly favorable habitats would increase significantly and expand into northern China, whereas the number of both favorable and marginally favorable habitats would decrease. Contrast analysis of EI values suggested that climate change and the density of site distribution were the main effectors of the changes in EI values. These results will help to improve control measures, prevent the spread of this pest, and revise the targeted quarantine areas. PMID:26496438

  14. On the large deformation behaviour of reinforced rubber at different temperatures

    NASA Astrophysics Data System (ADS)

    Lion, Alexander

    1997-11-01

    This essay investigates the temperature dependence of the mechanical properties of a filler-loaded tread compound experimentally and proposes a physically based method to represent this behaviour in the framework of non-linear continuum thermomechanics. To this end, we realise a series of monotonic and cyclic strain controlled tests on cylindrical specimens in tension at different temperature levels. The experimental data show the isothermal mechanical behaviour to be mainly influenced by non-linear elasticity in combination with non-linear rate dependence and weak equilibrium hysteresis. We observe that the rate sensitivity of the material depends strongly on the temperature : at low temperature levels, the rate sensitivity is essentially higher than at high temperatures. The elastic properties of the material depend comparatively less on the temperature. Nevertheless, higher temperature levels lead to higher equilibrium stresses. In order to represent the material behaviour, we start with a multiplicative split of the deformation gradient into a mechanical and a thermal part as proposed by Lu and Pister (1975). Physically, this idea corresponds to a stress-free thermal expansion followed by an isothermal stress-producing deformation. We suppose the thermal part of the deformation gradient to be isotropic. As a consequence of this, the velocity gradient decomposes additively into a pure thermal and a pure mechanical part. By using these elements, we exploit the Clausius Duhem inequality and assume the so-called 'mechanical second Piola Kirchhoff stress tensor' to be a functional of the 'mechanical Green's strain tensor'. In a further step, we define this functional by a system of constitutive equations which are based on a rheological model. The evolution equations for the internal variables are formulated by using the concept of dual variables proposed by Haupt and Tsakmakis (1989, 1996). The rate sensitivity is modelled by a stress and temperature dependent viscosity function. The elastic part of the equilibrium stress is described by entropy elasticity in combination with a modified Mooney Rivlin strain energy function. The equilibrium hysteresis effects are represented by rate independent plasticity in arclength representation as proposed by Valanis (1971). The constitutive model is compatible with the dissipation principle of thermodynamics and describes the general trend of the experimental data fairly well.

  15. Genetic potential of common bean progenies selected for crude fiber content obtained through different breeding methods.

    PubMed

    Jnior, V A P; Melo, P G S; Pereira, H S; Bassinello, P Z; Melo, L C

    2015-01-01

    Gastrointestinal health is of great importance due to the increasing consumption of functional foods, especially those concern-ing diets rich in fiber content. The common bean has been valorized as a nutritious food due to its appreciable fiber content and the fact that it is consumed in many countries. The current study aimed to evaluate and compare the genetic potential of common bean progenies of the carioca group, developed through different breeding methods, for crude fiber content. The progenies originated through hybridization of two advanced strains, CNFC 7812 and CNFC 7829, up to the F7 generation using three breeding methods: bulk-population, bulk within F2 families, and single seed descent. Fifteen F8 progenies were evaluated in each method, as well as two check cultivars and both parents, us-ing a 7 x 7 simple lattice design, with experimental plots comprised of two 4-m long rows. Field trials were conducted in eleven environments encompassing four Brazilian states and three different sowing times during 2009 and 2010. Estimates of genetic parameters indicate differences among the breeding methods, which seem to be related to the different processes for sampling the advanced progenies inherent to each method, given that the trait in question is not subject to natural selection. Variability amongst progenies occurred within the three breeding methods and there was also a significant effect of environment on the progeny for all methods. Progenies developed by bulk-population attained the highest estimates of genetic parameters, had less interaction with the environment, and greater variability. PMID:26125775

  16. Difference of Diagnostic Rates and Analytical Methods in the Test Positions of Vestibular Evoked Myogenic Potentials

    PubMed Central

    Park, Jeong Mee; Yong, Sang Yeol; Kim, Jong Heon; Kim, Hee; Park, Sang-Yoo

    2014-01-01

    Objective To compare the differences of diagnostic rates, of the two widely used test positions, in measuring vestibular evoked myogenic potentials (VEMP) and selecting the most appropriate analytical method for diagnostic criteria for the patients with vertigo. Methods Thirty-two patients with vertigo were tested in two comparative testing positions: turning the head to the opposite side of the evaluating side and bowing while in seated position, and bowing while in supine positions. Abnormalities were determined by prolonged latency of p13 or n23, shortening of the interpeak latency, and absence of VEMP formation. Results Using the three criteria above for determining abnormalities, both the seated and supine positions showed no significant differences in diagnostic rates, however, the concordance correlation of the two positions was low. When using only the prolonged latency of p13 or n23 in the two positions, diagnostic rates were not significantly different and their concordance correlation was high. On the other hand, using only the shortened interpeak latency in both positions showed no significant difference of diagnostic rates, and the degree of agreement between two positions was low. Conclusion Bowing while in seated position with the head turned in the opposite direction to the area being evaluated is found to be the best VEMP test position due to the consistent level of sternocleidomastoid muscle tension and the high level of compliance. Also, among other diagnostic analysis methods, using prolonged latency of p13 or n23 as the criterion is found to be the most appropriate method of analysis for the VEMP test. PMID:24855617

  17. Mechanism of milk secretion: milk composition in relation to potential difference across the mammary epithelium

    PubMed Central

    Peaker, M.

    1977-01-01

    1. In conscious lactating goats a significant correlation was found between bloodmilk potential difference (p.d.) and milk [lactose] such that in goats with a lower milk [lactose], milk was more negative with respect to blood. 2. When mannose was substituted for glucose in the substrate mixture of isolated perfused goat mammary glands, milk yield and milk [lactose] fell while milk [Na] and [K] increased; in parallel experiments the bloodmilk p.d. changed such that milk became more negative with respect to blood. These changes were reversed following the addition of glucose. 3. When milk was made hypertonic by the addition of hyperosmotic sucrose or lactose solutions, water entered milk osmotically and milk became electrically less negative or even positive with respect to blood in goats, cows and guinea-pigs. 4. No effect on p.d. was apparent following the addition of isosmotic sucrose to milk in goats. 5. When milk was held in the teat of goats by a pneumatic cuff around the base of the teat, no effect on p.d. was apparent when hyperosmotic sucrose was introduced into this teat pouch. 6. It is suggested that waterflow-induced potentials (the streaming potential and the transport number effect) can be induced across the mammary epithelium. 7. In goats exogenous oxytocin lowered milk [lactose] and bloodmilk p.d. became less negative with respect to blood. 8. In non-lactating and mastitic glands of goats the bloodmilk p.d. was within 05-25 mV of zero. 9. The effects of oxytocin, and the low p.d. in non-lactating and mastitic glands, are compatible with the view that in such circumstances there is a paracellular pathway across the mammary epithelium which partially short-circuits the two sides. 10. It is suggested that, with water being drawn osmotically into milk to dilute newly formed lactose, waterflow-induced potentials may be responsible for establishing the normal p.d. across the apical membrane of the secretary cell, thereby keeping milk [K] and [Na] lower than in intracellular fluid. PMID:903903

  18. Click-evoked potentials in a large marine mammal, the adult male northern elephant seal (Mirounga angustirostris).

    PubMed

    Houser, Dorian S; Crocker, Daniel E; Finneran, James J

    2008-07-01

    Auditory evoked potential (AEP) hearing studies in marine mammals should consider an expected size-dependent reduction in AEP amplitude. This study is the first to measure the click-evoked response in a large marine mammal, the adult male elephant seal (Mirounga angustirostris). Click stimuli were presented at peak-peak equivalent sound pressure levels of 117-118 dB re: 20 microPa. Three positive peaks (P1-P3) and two negative peaks (N4 and N5) were observed in the AEP. Response latencies were longer than previously observed in a 1.8 yr old seal and the maximum peak-peak amplitude was comparatively reduced by more than 60%. The inverse relationship between size and AEP amplitude will likely require increased averaging with larger subjects and possibly modifications to electrode placement and design in order to increase the quality of recorded evoked responses. PMID:18646953

  19. The "Large" in Large Igneous Provinces: Using Digital Geological Maps to Determine the Area, Magma Flux, and Potential Environmental Impact of the Wrangellia Flood Basalts

    NASA Astrophysics Data System (ADS)

    Scoates, J. S.; Greene, A. R.; Weis, D. A.

    2010-12-01

    Large igneous provinces (LIPs), such as continental flood basalts and oceanic plateaus, are formed by relatively short duration, massive outpourings of basalt in intraplate settings. Their emplacement has been associated with global climatic and biotic change (e.g., end-Permian Siberian LIP). The magmatic products of a LIP typically cover an area >1 Mkm2, however erosion and exhumation may substantially reduce the original area and volume of a LIP, especially oceanic plateaus that have been tectonically dispersed during accretion (e.g., Caribbean, Wrangellia). The availability of digital geologic maps from government geologic surveys now allows for measuring the precise areal distribution of remnant LIP-products, which is essential information for estimating total volumes and ultimately potential environmental effects. The Wrangellia flood basalts represent one of the best-exposed accreted oceanic plateaus on Earth. This Triassic LIP is exposed in numerous fault-bound blocks in a belt extending discontinuously for 2300 km in the Pacific Northwest of North America. It contains exposures of submarine and subaerial volcanic rocks representing composite stratigraphic thicknesses of 3.5-6 km. From recently compiled digital geologic maps (British Columbia, Yukon, Alaska), the mapped exposures of the Wrangellia flood basalts are relatively small (25,256 km2 with 75% from Vancouver Island), which leads to minimum calculated erupted volumes of up to 1.4 x 105 km3 and an estimated magma flux of 0.03 km3/yr. The original areal distribution was substantially greater, perhaps by an order of magnitude or more, as the outcrop extent does not include regions covered by younger strata and surficial deposits nor does it account for the volcanic component of the terrane that may have been subducted. However, even this minimum volumetric output rate is comparable to recent estimates of long-term volumetric eruption rates for ocean islands such as Iceland (0.02-0.04 km3/yr) and Hawaii (0.02-0.08 km3/yr) [1]. The Wrangellia flood basalts were emplaced during a single phase of tholeiitic volcanism at ca. 230 Ma, possibly within as few as 2 Myr, onto preexisting submerged arc crust in equatorial latitudes in the eastern Panthalassic Ocean. This age corresponds to the Carnian-Norian boundary of the Upper Triassic [2], a time of global-scale climatic and biotic crisis, which was followed by strong radiation of the dinosaurs. A combination of precise U-Pb geochronology of the Wrangellia basalts, area/magma flux estimates (including integration of geophysical seismic reflection profiles to account for plutonic components) and quantification of the associated volatile production will be required to fully evaluate this potential link between volcanic activity and global environmental impacts. [1] White, S.M. et al. (2006) Geochemistry Geophysics Geosystems, 7, Q03010, doi: 10.1029/2005GC001002. [2] Furin, S. et al. (2006) Geology 34, 1009-1012, doi: 10.1130/G22967A.1.

  20. On the formulation of gravitational potential difference between the GRACE satellites based on energy integral in Earth fixed frame

    NASA Astrophysics Data System (ADS)

    Zeng, Y. Y.; Guo, J. Y.; Shang, K.; Shum, C. K.; Yu, J. H.

    2015-09-01

    Two methods for computing gravitational potential difference (GPD) between the GRACE satellites using orbit data have been formulated based on energy integral; one in geocentric inertial frame (GIF) and another in Earth fixed frame (EFF). Here we present a rigorous theoretical formulation in EFF with particular emphasis on necessary approximations, provide a computational approach to mitigate the approximations to negligible level, and verify our approach using simulations. We conclude that a term neglected or ignored in all former work without verification should be retained. In our simulations, 2 cycle per revolution (CPR) errors are present in the GPD computed using our formulation, and empirical removal of the 2 CPR and lower frequency errors can improve the precisions of Stokes coefficients (SCs) of degree 3 and above by 1-2 orders of magnitudes. This is despite of the fact that the result without removing these errors is already accurate enough. Furthermore, the relation between data errors and their influences on GPD is analysed, and a formal examination is made on the possible precision that real GRACE data may attain. The result of removing 2 CPR errors may imply that, if not taken care of properly, the values of SCs computed by means of the energy integral method using real GRACE data may be seriously corrupted by aliasing errors from possibly very large 2 CPR errors based on two facts: (1) errors of bar C_{2,0} manifest as 2 CPR errors in GPD and (2) errors of bar C_{2,0} in GRACE data-the differences between the CSR monthly values of bar C_{2,0} independently determined using GRACE and SLR are a reasonable measure of their magnitude-are very large. Our simulations show that, if 2 CPR errors in GPD vary from day to day as much as those corresponding to errors of bar C_{2,0} from month to month, the aliasing errors of degree 15 and above SCs computed using a month's GPD data may attain a level comparable to the magnitude of gravitational potential variation signal that GRACE was designed to recover. Consequently, we conclude that aliasing errors from 2 CPR errors in real GRACE data may be very large if not properly handled; and therefore, we propose an approach to reduce aliasing errors from 2 CPR and lower frequency errors for computing SCs above degree 2.

  1. Assessing the impact of different satellite retrieval methods on forecast available potential energy

    NASA Technical Reports Server (NTRS)

    Whittaker, Linda M.; Horn, Lyle H.

    1990-01-01

    The effects of the inclusion of satellite temperature retrieval data, and of different satellite retrieval methods, on forecasts made with the NASA Goddard Laboratory for Atmospheres (GLA) fourth-order model were investigated using, as the parameter, the available potential energy (APE) in its isentropic form. Calculation of the APE were used to study the differences in the forecast sets both globally and in the Northern Hemisphere during 72-h forecast period. The analysis data sets used for the forecasts included one containing the NESDIS TIROS-N retrievals, the GLA retrievals using the physical inversion method, and a third, which did not contain satellite data, used as a control; two data sets, with and without satellite data, were used for verification. For all three data sets, the Northern Hemisphere values for the total APE showed an increase throughout the forecast period, mostly due to an increase in the zonal component, in contrast to the verification sets, which showed a steady level of total APE.

  2. Potential Large Animal Models for Gene Therapy of Human Genetic Diseases of Immune and Blood Cell Systems

    PubMed Central

    Bauer, Thomas R.; Adler, Rima L.; Hickstein, Dennis D.

    2009-01-01

    Genetic mutations involving the cellular components of the hematopoietic system—red blood cells, white blood cells, and platelets—manifest clinically as anemia, infection, and bleeding. Although gene targeting has recapitulated many of these diseases in mice, these murine homologues are limited as translational models by their small size and brief life span as well as the fact that mutations induced by gene targeting do not always faithfully reflect the clinical manifestations of such mutations in humans. Many of these limitations can be overcome by identifying large animals with genetic diseases of the hematopoietic system corresponding to their human disease counterparts. In this article, we describe human diseases of the cellular components of the hematopoietic system that have counterparts in large animal species, in most cases carrying mutations in the same gene (CD18 in leukocyte adhesion deficiency) or genes in interacting proteins (DNA cross-link repair 1C protein and protein kinase, DNA-activated, catalytic polypeptide in radiation-sensitive severe combined immunodeficiency). Furthermore, we describe the potential of these animal models to serve as disease-specific, preclinical models for testing the efficacy and safety of clinical interventions such as hematopoietic stem cell transplantation or gene therapy approaches before their use in humans with the corresponding disease. PMID:19293460

  3. Role of the outer pore domain in transient receptor potential vanilloid 1 dynamic permeability to large cations.

    PubMed

    Munns, Clare H; Chung, Man-Kyo; Sanchez, Yuly E; Amzel, L Mario; Caterina, Michael J

    2015-02-27

    Transient receptor potential vanilloid 1 (TRPV1) has been shown to alter its ionic selectivity profile in a time- and agonist-dependent manner. One hallmark of this dynamic process is an increased permeability to large cations such as N-methyl-D-glucamine (NMDG). In this study, we mutated residues throughout the TRPV1 pore domain to identify loci that contribute to dynamic large cation permeability. Using resiniferatoxin (RTX) as the agonist, we identified multiple gain-of-function substitutions within the TRPV1 pore turret (N628P and S629A), pore helix (F638A), and selectivity filter (M644A) domains. In all of these mutants, maximum NMDG permeability was substantially greater than that recorded in wild type TRPV1, despite similar or even reduced sodium current density. Two additional mutants, located in the pore turret (G618W) and selectivity filter (M644I), resulted in significantly reduced maximum NMDG permeability. M644A and M644I also showed increased and decreased minimum NMDG permeability, respectively. The phenotypes of this panel of mutants were confirmed by imaging the RTX-evoked uptake of the large cationic fluorescent dye YO-PRO1. Whereas none of the mutations selectively altered capsaicin-induced changes in NMDG permeability, the loss-of-function phenotypes seen with RTX stimulation of G618W and M644I were recapitulated in the capsaicin-evoked YO-PRO1 uptake assay. Curiously, the M644A substitution resulted in a loss, rather than a gain, in capsaicin-evoked YO-PRO1 uptake. Modeling of our mutations onto the recently determined TRPV1 structure revealed several plausible mechanisms for the phenotypes observed. We conclude that side chain interactions at a few specific loci within the TRPV1 pore contribute to the dynamic process of ionic selectivity. PMID:25568328

  4. Role of the Outer Pore Domain in Transient Receptor Potential Vanilloid 1 Dynamic Permeability to Large Cations*

    PubMed Central

    Munns, Clare H.; Chung, Man-Kyo; Sanchez, Yuly E.; Amzel, L. Mario; Caterina, Michael J.

    2015-01-01

    Transient receptor potential vanilloid 1 (TRPV1) has been shown to alter its ionic selectivity profile in a time- and agonist-dependent manner. One hallmark of this dynamic process is an increased permeability to large cations such as N-methyl-d-glucamine (NMDG). In this study, we mutated residues throughout the TRPV1 pore domain to identify loci that contribute to dynamic large cation permeability. Using resiniferatoxin (RTX) as the agonist, we identified multiple gain-of-function substitutions within the TRPV1 pore turret (N628P and S629A), pore helix (F638A), and selectivity filter (M644A) domains. In all of these mutants, maximum NMDG permeability was substantially greater than that recorded in wild type TRPV1, despite similar or even reduced sodium current density. Two additional mutants, located in the pore turret (G618W) and selectivity filter (M644I), resulted in significantly reduced maximum NMDG permeability. M644A and M644I also showed increased and decreased minimum NMDG permeability, respectively. The phenotypes of this panel of mutants were confirmed by imaging the RTX-evoked uptake of the large cationic fluorescent dye YO-PRO1. Whereas none of the mutations selectively altered capsaicin-induced changes in NMDG permeability, the loss-of-function phenotypes seen with RTX stimulation of G618W and M644I were recapitulated in the capsaicin-evoked YO-PRO1 uptake assay. Curiously, the M644A substitution resulted in a loss, rather than a gain, in capsaicin-evoked YO-PRO1 uptake. Modeling of our mutations onto the recently determined TRPV1 structure revealed several plausible mechanisms for the phenotypes observed. We conclude that side chain interactions at a few specific loci within the TRPV1 pore contribute to the dynamic process of ionic selectivity. PMID:25568328

  5. Advances towards using finger/toenail dosimetry to triage a large population after potential exposure to ionizing radiation

    PubMed Central

    He, Xiaoming; Gui, Jiang; Matthews, Thomas P.; Williams, Benjamin B.; Swarts, Steven G.; Grinberg, Oleg; Sidabras, Jason; Wilcox, Dean E.; Swartz, Harold M.

    2011-01-01

    Rapid and accurate retrospective dosimetry is of critical importance and strategic value for the emergency medical response to a large-scale radiological/nuclear event. One technique that has the potential for rapid and accurate dosimetry measurements is electron paramagnetic resonance (EPR) spectroscopy of relatively stable radiation-induced signals (RIS) in fingernails and toenails. Two approaches are being developed for EPR nail dosimetry. In the approach using ex vivo measurements on nail clippings, accurate estimation of the dose-dependent amplitude of the RIS is complicated by the presence of mechanically-induced signals (MIS) that are generated during the nail clipping. Recent developments in ex vivo nail dosimetry, including a thorough characterization of the MIS and an appreciation of the role of hydration and the development of effective analytic techniques, have led to improvements in the accuracy and precision of this approach. An in vivo nail dosimetry approach is also very promising, as it eliminates the problems of MIS from the clipping and it has the potential to be an effective and efficient approach for field deployment. Two types of EPR resonators are being developed for in vivo measurements of fingernails and toenails. PMID:22125410

  6. Advances towards using finger/toenail dosimetry to triage a large population after potential exposure to ionizing radiation.

    PubMed

    He, Xiaoming; Gui, Jiang; Matthews, Thomas P; Williams, Benjamin B; Swarts, Steven G; Grinberg, Oleg; Sidabras, Jason; Wilcox, Dean E; Swartz, Harold M

    2011-09-01

    Rapid and accurate retrospective dosimetry is of critical importance and strategic value for the emergency medical response to a large-scale radiological/nuclear event. One technique that has the potential for rapid and accurate dosimetry measurements is electron paramagnetic resonance (EPR) spectroscopy of relatively stable radiation-induced signals (RIS) in fingernails and toenails. Two approaches are being developed for EPR nail dosimetry. In the approach using ex vivo measurements on nail clippings, accurate estimation of the dose-dependent amplitude of the RIS is complicated by the presence of mechanically-induced signals (MIS) that are generated during the nail clipping. Recent developments in ex vivo nail dosimetry, including a thorough characterization of the MIS and an appreciation of the role of hydration and the development of effective analytic techniques, have led to improvements in the accuracy and precision of this approach. An in vivo nail dosimetry approach is also very promising, as it eliminates the problems of MIS from the clipping and it has the potential to be an effective and efficient approach for field deployment. Two types of EPR resonators are being developed for in vivo measurements of fingernails and toenails. PMID:22125410

  7. Differences in female individual reproductive potential among three stocks of winter flounder, Pseudopleuronectes americanus

    NASA Astrophysics Data System (ADS)

    McElroy, W. David; Wuenschel, Mark J.; Press, Yvonna K.; Towle, Emilee K.; McBride, Richard S.

    2013-01-01

    Potential annual fecundity (PAF) and skipped spawning of winter flounder, Pseudopleuronectes americanus, were compared among the three stocks in United States waters and between two spawning seasons. Winter flounder have group-synchronous oocyte development and determinate fecundity. These characteristics enable estimation of PAF just prior to spawning by enumeration of the late-vitellogenic cohort of oocytes, in this case employing the autodiametric method. There was a low level of down-regulation, which was limited to fish in the earlier stages of vitellogenesis. Estimates of PAF increased substantially with female size and age, ranging from < 0.5 million to > 5 million eggs per female. Fecundity at size decreased with increasing latitude. On average, fish from the Southern New England (SNE) stock had the highest individual fecundities at length and Gulf of Maine (GOM) the lowest, but differences varied among the years. Fecundity at length of fish from Georges Bank (GB) was intermediate to these two stocks and displayed less variability at size; however, GB fish grow faster so they had the highest relative fecundity at age. Skipped spawning also exhibited geographic differences; it was infrequent (< 2%) overall, but observed in the two coastal stocks (GOM more than SNE) in both years and was not observed in the GB stock. Fecundity at size between the two years was more similar for SNE fish, but all three stocks were synchronized with higher PAF in 2011 than 2010. Comparisons to previously published estimates suggest fecundity is highly variable in this species. Overall, different rates of reproductive productivity exist among individuals of the three stocks.

  8. Transcriptome Profile at Different Physiological Stages Reveals Potential Mode for Curly Fleece in Chinese Tan Sheep

    PubMed Central

    Liu, Yufang; Xu, Qinqin; Zhang, Ming; Fang, Meiying

    2013-01-01

    Tan sheep (Ovis aries), a Chinese indigenous breed, has special curly fleece after birth, especially at one month old. However, this unique phenotype disappears gradually with age and the underlying reasons of trait evolvement are still unknown. In this study, skin transcriptome data was used to study this issue. In total 51,215 transcripts including described transcripts and transfrags were identified. Pathway analysis of the top 100 most highly expressed transcripts, which included TCHH and keratin gene family members, such as KRT25, KRT5, KRT71, KRT14 and others, showed pathways known to be relevant to hair/fleece development and function. Six hundred differentially expressed (DE) transcripts were detected at two different physiological ages (one-month-old with curly fleece and 48-month-old without curly fleece) and were categorized into three major functional groups: cellular component, molecular function, and biological process. The top six functional categories included cell, cell part, cellular process, binding, intracellular, metabolic process. The detected differentially expressed genes were particularly involved in signal, signal peptide, disulfide bond, glycoprotein and secreted terms, respectively. Further splicing isoform analysis showed that the metallothionein 3 isoform was up-regulated in Tan lamb skin, indicating that it may be related to the conformation of curly fleece in Chinese Tan lamb. The hair-related important differentially expressed genes (SPINK4, FGF21, ESR?, EphA3, NTNG1 and GPR110) were confirmed by qPCR analysis. We deduced that the differences existed in expressed transcripts, splice isoforms and GO categories between the two different physiological stages, which might constitute the major reasons for explaining the trait evolvement of curly fleece in Chinese Tan sheep. This study provides some clues for elucidating the molecular mechanism of fleece change with age in Chinese Tan sheep, as well as supplying some potential values for understanding human hair disorder and texture changes. PMID:23990983

  9. Regenerative potential of immature permanent non-vital teeth following different dentin surface treatments.

    PubMed

    El Ashry, Salma H; Abu-Seida, Ashraf M; Bayoumi, Amr A; Hashem, Ahmed A

    2016-01-01

    This study evaluates the regenerative potential of immature permanent non-vital teeth following different dentin surface treatments in dogs. Periapical lesions and necrotic pulps were induced in 288 roots of 144 teeth in twelve dogs. Teeth were randomly divided into 3 equal groups according to the evaluation period. Each group was subdivided into 8 subgroups according to the treatment modalities including; blood clot, blood clot and collagen, blood clot and Ethylenediaminetetraacetic acid (EDTA), blood clot, collagen and EDTA, blood clot and Mixture Tetracycline Citric Acid and Detergent (MTAD), blood clot, collagen and MTAD, positive control and negative control. Apart from control subgroups, all infected root canals were cleaned with sodium hypochlorite solution and triple antibiotics paste before different treatment protocols. After different treatments, the root length, thickness and apical diameter were evaluated by radiographic examination. Histopathological examination was carried out to evaluate the inflammation, bone/root resorption, tissue in-growth in pulp space, new hard tissue formation and apical closure. Using EDTA solution as a surface modifier showed significantly higher levels of tissue in-growth in the pulp space after 6 weeks and 3 months. Addition of collagen as a scaffold caused significantly more bone/root resorption than the other subgroups while EDTA caused significantly lower inflammatory cell counts only after 2 weeks. Final rinse with 17% EDTA solution before blood clot induction has positive impact on tissue interaction along dentinal walls without modification of the cell type. Moreover, the use of collagen as a scaffold material and MTAD as a surface modifier did not improve the quality of the regenerative process. PMID:26683411

  10. Sediment pollution in the Elbe estuary and its potential toxicity at different trophic levels.

    PubMed

    Wetzel, Markus A; Wahrendorf, Dierk-Steffen; von der Ohe, Peter C

    2013-04-01

    Sediment contamination is one of the most pressing environmental problems in estuaries of industrialized countries and is of special interest to water managers involved in waterway maintenance dredging. In the present study, eight heavy metals (As, Pb, Cd, Cr, Cu, Ni, Hg, and Zn) and 41 organic compounds (pentachlorbenzol (PeCB), hexachlorbenzol (HCB), 7 polychlorinated biphenyls (PCBs), the hexachlorocyclohexanes ?-HCH, ?-HCH, ?-HCH, 6 dichlorodiphenyltrichloroethane isomers, organochlorine styrene (OCS), octachloronaphthalene (OCN), 15 polycyclic aromatic hydrocarbons (PAHs), and 6 organotin (OT) compounds) were analyzed in surface sediments at 36 sites in the Elbe estuary in 2006. Correlation analysis showed a general decrease in sediment contaminant concentrations from the stations near the port of Hamburg towards the open sea. This decrease was significant (Spearman's rank correlation, p<0.05) with most pollutants. In addition, cluster analysis identified five groups of sites with different sediment contaminant patterns within the Elbe estuary. Worst case toxic risks stemming from sediment-bound organic pollutants were predicted using the Toxic Unit approach, based on estimated pore-water concentrations under equilibrium conditions and acute LC50 values for three standard test organisms of the trophic levels of fish, invertebrates, and algae. The estimated sediment toxicity was significantly higher in the inner part (river-km 630 to 660) compared with the estuarine mouth. Moreover, potential toxicity of organic pollutants estimated for invertebrates and for fish exceeded acute-based effect thresholds at 30 and 24 stations, respectively. Chronic effects for invertebrates are expected at all sites investigated. We conclude that sediment pollution and related potential toxicity in the Elbe estuary may have more influence on the benthos fauna than expected to date. PMID:23428749

  11. Fast and simple determination of perfluorinated compounds and their potential precursors in different packaging materials.

    PubMed

    Zabaleta, I; Bizkarguenaga, E; Bilbao, D; Etxebarria, N; Prieto, A; Zuloaga, O

    2016-05-15

    A simple and fast analytical method for the determination of fourteen perfluorinated compounds (PFCs), including three perfluoroalkylsulfonates (PFSAs), seven perfluorocarboxylic acids (PFCAs), three perfluorophosphonic acids (PFPAs) and perfluorooctanesulfonamide (PFOSA) and ten potential precursors, including four polyfluoroalkyl phosphates (PAPs), four fluorotelomer saturated acids (FTCAs) and two fluorotelomer unsaturated acids (FTUCAs) in different packaging materials was developed in the present work. In order to achieve this objective the optimization of an ultrasonic probe-assisted extraction (UPAE) method was carried out before the analysis of the target compounds by liquid-chromatography-triple quadrupole-tandem mass spectrometry (LC-QqQ-MS/MS). 7mL of 1 % acetic acid in methanol and a 2.5-min single extraction cycle were sufficient for the extraction of all the target analytes. The optimized analytical method was validated in terms of recovery, precision and method detection limits (MDLs). Apparent recovery values after correction with the corresponding labeled standard were in the 69-103 % and 62-98 % range for samples fortified at 25ng/g and 50ng/g concentration levels, respectively and MDL values in the 0.6-2.2ng/g range were obtained. The developed method was applied to the analysis of plastic (milk bottle, muffin cup, pre-cooked food wrapper and cup of coffee) and cardboard materials (microwave popcorn bag, greaseproof paper for French fries, cardboard box for pizza and cinema cardboard box for popcorn). To the best of our knowledge, this is the first method that describes the determination of fourteen PFCs and ten potential precursors in packaging materials. Moreover, 6:2 FTCA, 6:2 FTUCA and 5:3 FTCA analytes were detected for the first time in microwave popcorn bags. PMID:26992531

  12. Nuclear DNA Content and Chromatin Pattern of Rat Rhabdomyosarcoma Cell Sublines with Different Metastatic Potentials

    PubMed Central

    Dufer, Jean; Poupon, Marie-France; Yatouji, Sonia

    2000-01-01

    There is a constant need of features able to characterize potentially metastatic cells among the heterogeneous cell subpopulations which constitute a tumor. Image cytometry of metastatic tumor cells give rise to variable results, partly because of a heterogeneous origin of cells, or potential drug effects. The aim of this work was to characterize nuclear changes observed in metastatic cell clones issued in vitro from the same parental cell population The nuclear phenotypes of 6 cell sublines isolated from a rat rhabdomyosarcoma cell line and differing in their metastatic ability were evaluated by image cytometry on Feulgen?stained preparations. Densitometric [5], geometric [3] and textural [9] features were computed from each nuclear image. For each cell subline, a metastatic score, ranging from 0 to 10, was calculated on the basis of in vitro invasivity data, by measuring the number of pulmonary metastases observed after s.c. graft of tumor cells in rats. Data obtained were compared to karyotype, growth characteristics, and oncogene expressions of cell lines. The nuclear DNA content, the chromosome numbers, the cell sublines doubling times, and the distribution of cells within the cell cycle appear unrelated with this score. On the contrary, increase in metastatic ability is accompanied by changes in chromatin pattern as assessed by textural features. Progressive increase in chromatin condensation can be observed in cell sublines with increasing metastatic score. These results were confirmed by an unsupervised multivariate partitioning of rhabdomyosarcoma cells which identified two separate subsets whose distributions within the analyzed cell lines correlate with their metastatic ability. These data suggest that, in rat rhabdomyosarcoma cell sublines, metastatic ability could be associated with nuclear morphological changes at the level of chromatin texture. PMID:11007437

  13. The role of water nitrogen retention in integrated nutrient management: assessment in a large basin using different modelling approaches

    NASA Astrophysics Data System (ADS)

    Grizzetti, Bruna; Passy, Paul; Billen, Gilles; Bouraoui, Fayçal; Garnier, Josette; Lassaletta, Luis

    2015-06-01

    Assessing the removal of nitrogen (temporary and permanent) in large river basins is complex due to the dependency on climate, hydrological and physical characteristics, and ecosystems functioning. Measurements are generally limited in number and do not account for the full integration of all processes contributing to nitrogen retention in the river basin. However, the estimation of nitrogen retention by the ecosystems is crucial to understanding the nitrate water pollution and the N2O emissions to the atmosphere, as well as the lag time between the implementation of agri-environmental measures to reduce nitrogen pollution and the improvement of water quality. Models have often been used to understand the dynamics of the river basin system. The objective of this study was to assess nitrogen retention in a large river basin, the Seine basin (∼65 000 km2, in France), through the application of three models with different levels of complexity developed for different specific purposes: the GREEN, SWAT and RiverStrahler models. The study analyses the different modelling approaches and compares their estimates of water nitrogen retention over an 11-year period. Then reflexions on the role played by nitrogen retention by aquatic ecosystems in integrated nutrient management are presented. The results of this study are relevant for the understanding of nitrogen retention processes at the large river basin scale and for the analysis of mitigation measure scenarios designed to reduce nitrogen impacts on aquatic ecosystems and climate.

  14. Potentials and constraints of different types of soil moisture observations for flood simulations in headwater catchments

    NASA Astrophysics Data System (ADS)

    Bronstert, A.; Creutzfeldt, B.; Graeff, T.; Hajnsek, I.; Heistermann, M.; Itzerott, S.; Jagdhuber, T.; Kneis, D.; Lck, E.; Reusser, D.; Zehe, E.

    2012-04-01

    Flood generation in mountainous headwater catchments is governed by rainfall intensities, by the spatial distribution of rainfall and by the state of the catchment prior to the rainfall, e.g. by the spatial pattern of the soil moisture, groundwater conditions, and possibly snow. The work presented here explores the limits and potentials of measuring soil moisture with different methods and in different scales and their potential use for flood simulation. These measurements were obtained in 2007 and 2008 within a comprehensive multi-scale experiment in the Weisseritz headwater catchment in the Ore-Mountains, Germany. The following technologies have been applied jointly thermogravimetric method, Frequency Domain Reflectometry (FDR) sensors, Spatial-Time Domain Reflectometry (STDR) cluster, Ground Penetrating Radar (GPR), airborne polarimetric synthetic aperture radar (polarimetric-SAR) and Advanced Synthetic Aperture Radar (ASAR) based on the satellite Envisat. We present exemplary soil measurement results, with spatial scales ranging from point scale, via hillslope and field scale to the catchment scale. Only the Spatial-TDR cluster was able to record continuous data. The other methods are limited to the date of over flights (airplane and satellite) or measurement campaigns on the ground. At a first glance, using soil moisture data to initiate better flood modelling (including flood forecasts) seems to be a rather straight forward approach. However, this approach bears several problems regarding the operational use of such data and the model parameterisation: 1) A main constraint is that the observation of spatially distributed soil moisture and the subsequent data processing are still far from an operational stage because continuous or quasi-continuous air-borne observation and processing of soil moisture is not available; 2) remote soil moisture sensors observe only a quite shallow soil depths, which are of restricted relevance for flood generation and water budgets, 3) satellite data are not yet readily available continuously and in a way that they can be used directly for flood forecasting, and 4) hydrological models which can directly process such information are not readily available.

  15. Repeatability and Diagnostic Value of Nasal Potential Difference in a Genetically Admixed Population

    PubMed Central

    Sad, Izabela Rocha; Higa, Laurinda Yoko Shinzato; Leal, Teresinha; Martins, Raisa da Silva; de Almeida, Ana Claudia; Ramos, Eloane Goncalves; de Cabello, Giselda Maria Kalil; Peixoto, Maria Virginia Marques

    2016-01-01

    Background The genetic diversity of the Brazilian population results from three ethnic groups admixture: Europeans, Africans and Amerindians, thus increasing the difficulty of performing cystic fibrosis (CF) diagnosis. The nasal potential difference (NPD) evaluates the cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) activity. Despite being a useful CF diagnostic test and a biomarker of CFTR-modulator drugs, it is also highly operator dependent. Therefore, it may be difficult to get accurate results and to interpret them. Wilschanski and Sermet scores were proposed to address these issues. This study aimed to evaluate repeatability and diagnostic value of NPD parameters and Wilschanski and Sermet scores in a CF center in Rio de Janeiro. Methods NPD was performed in 78 subjects. Maximal PD, amiloride response, total chloride response, and Wilschanski and Sermet scores were explored as means (confidence interval, CI). One-way ANOVA was used to compare mean differences and Scheffe test was used to pair-wise comparisons. Repeatability was evaluated by scatter and Bland-Altman plots. The Ethics Committee of the CF Center has approved the study protocol. Parents and adult participants signed an informed consent form. Results Forty-eight healthy-volunteers, 19 non-CF and 11 CF patients were enrolled in this study. Significant differences were found when comparing CF patients NPD parameters to the other two groups (P = 0.000). Moreover, no significant differences were found when parameters from non-CF patients were compared with those from healthy volunteers (P > 0.05). The means of NPD parameters and diagnostic scores of each group were in concordance with disease/non-disease conditions. The repeatability data - Wilschanski and Sermet and NPD - allow NPD to be performed in this Brazilian CF Center. Conclusions The present study gathered consistent data for Bland-Altman plots. The results of Wilschanski and Sermet diagnostic scores suggest that they were concordant with CF/non-CF conditions. More NPD tests should be performed in the Rio de Janeiro CF dynamic cohort to contribute to international NPD validation studies and to provide NPD as a biomarker in Brazil. PMID:26668678

  16. A method for visualization of omic datasets for sphingolipid metabolism to predict potentially interesting differences[S

    PubMed Central

    Momin, Amin A.; Park, Hyejung; Portz, Brent J.; Haynes, Christopher A.; Shaner, Rebecca L.; Kelly, Samuel L.; Jordan, I. King; Merrill, Alfred H.

    2011-01-01

    Sphingolipids are structurally diverse and their metabolic pathways highly complex, which makes it difficult to follow all of the subspecies in a biological system, even using lipidomic approaches. This report describes a method to use transcriptomic data to visualize and predict potential differences in sphingolipid composition, and it illustrates its use with published data for cancer cell lines and tumors. In addition, several novel sphingolipids that were predicted to differ between MDA-MB-231 and MCF7 cells based on published microarray data for these breast cancer cell lines were confirmed by mass spectrometry. For the data that we were able to find for these comparisons, there was a significant match between the gene expression data and sphingolipid composition (P < 0.001 by Fisher's exact test). Upon considering the large number of gene expression datasets produced in recent years, this simple integration of two types of omic technologies (transcriptomics to direct sphingolipidomics) might facilitate the discovery of useful relationships between sphingolipid metabolism and disease, such as the identification of new biomarkers. PMID:21415121

  17. Variation potential propagation decreases heat-related damage of pea photosystem I by 2 different pathways.

    PubMed

    Surova, Lyubov; Sherstneva, Oksana; Vodeneev, Vladimir; Sukhov, Vladimir

    2016-03-01

    Local burning is known to generate and propagate variation potential (VP) in plants. VP affects different physiological processes, including reducing heat-related damage to photosystem I (PSI). We investigated mechanisms of the process. Photosynthesis parameters were measured with Dual-PAM-100 and GFS-3000. VP was induced by burning the first mature leaf and then waiting 5, 10, 15, or 20 min to initiate heating of the second mature leaf. Photosystems activities in the second leaf were investigated at 15 and 135 min after heating. In the absence of VP induction, when incubation in hot water (5 min) was used for heating the intact second leaf, PSI and PSII activities decreased after incubation at both exposure temperatures (45°C and 50°C). When local burning of the first leaf induced VP propagation into the second leaf, reduced photosynthesis (PSI) was observed. Arrival of VP in the second leaf prior to hot water incubation at 50°C decreased heating-induced suppression of PSI activity when measured 15 and 135 min later. Dependence of PSI activity on the time interval (5, 10, 15, or 20 min) between VP induction and heating of the second leaf was dissimilar at 15 and 135 min. Heat-induced suppression of PSII activity in the second leaf was stimulated after VP induction. In contrast, the effect of VP on PSI and PSII damage was weak when leaf 2 was heated at 45°C. VP-induced decrease of PSI activity suppression at 15 min after heating was correlated with stimulation of PSII activity suppression, but increase of PSI activity at 135 min after heating was not related to PSII activity. Thus, our results suggest the possibility of 2 different pathways of VP-induced decrease of heat-related PSI damage. PMID:26853242

  18. Protein and mRNA characterization in human colorectal carcinoma cell lines with different metastatic potentials.

    PubMed

    Liang, Li; Qu, Lijuan; Ding, Yanqing

    2007-09-01

    Metastasis, the important characteristic of malignant tumors, is closely associated with a series of changes in the expressions of genes and proteins. In this study, we compared mRNA and protein expressions in a pair of human colorectal carcinoma cell lines named SW620 and SW480 with different metastatic potentials by suppression subtractive hybridization and 2-dimensional gel electrophoresis combined with the matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. After suppression subtractive hybridization and differential screening, 24 differentially expressed gene fragments were obtained, including 9 known genes and 15 novel genes. Nine known genes, such as Cytochrome C, Oxidase II and III, Serum amyloid A, Mitotic Control Protein dis3, Eukaryotic Translation Initiation Factor 4A, function in the process of growth and differentiation, transcription, apoptosis, signal transduction. Six novel genes were found to locate in chromosome 5. Northern blot further confirmed the results. For protein analysis, 16 significantly different protein spots were detected using 2-dimensional gel electrophoresis and peptide mass fingerprinting analysis. The results were confirmed by Western blot. The peptide mass fingerprintings of spots were then compared with the NCBI and SWISS PROT database. The differentially expressed proteins included Galectin-1, Annexin A1, Casein kinase 2, Cytochrome c oxidase subunit VIb, S-100D calcium-binding protein, which may be involved in cell differentiation and proliferation, signal transduction, cell adhesion and migration, and tumor evasion of immune responses. An analysis of these genes and proteins reiterated much of our understanding of the metastatic process and also offered some identified targets without previously characterized functions, especially the novel metastasis associated genes, to be further investigated. Moreover, the results of the phenotypic function-related expression mapping analysis at the mRNA and protein level revealed obvious complementarities, providing important clues for further study of the molecular mechanism of metastasis, metastasis control and possible targets for cancer gene therapy. PMID:17882654

  19. Contrasting Nutrient Mitigation and Denitrification Potential of Agricultural Drainage Environments with Different Emergent Aquatic Macrophytes.

    PubMed

    Taylor, Jason M; Moore, Matthew T; Scott, J Thad

    2015-07-01

    Remediation of excess nitrogen (N) in agricultural runoff can be enhanced by establishing wetland vegetation, but the role of denitrification in N removal is not well understood in drainage ditches. We quantified differences in N retention during experimental runoff events followed by stagnant periods in mesocosms planted in three different vegetation treatments: unvegetated, cutgrass [ (L.) Sw.], and common cattail ( L.). We also quantified denitrification rates using membrane inlet mass spectrometry from intact cores extracted from each mesocosm treatment. All treatments retained 60% or more of NO-N loads during the 6-h experimental runoff event, but mesocosms planted with cutgrass had significantly higher (68%) retention than the cattail (60%) or unvegetated (61%) treatments. After the runoff event, mesocosms planted in cattail reduced NO-N concentrations by >95% within 24 h and cutgrass achieved similar reductions within 48 h, whereas reductions in the unvegetated mesocosms were significantly less (65%). Cores from cutgrass mesocosms had significantly higher average denitrification rates (5.93 mg m h), accounting for as much as 56% of the immobilized NO-N within 48 h, whereas denitrification rates were minimal in cores from the unvegetated (-0.19 mg m h) and cattail (0.2 mg m h) mesocosms. Our findings have implications for mitigating excess NO-N in agricultural runoff. While vegetated treatments removed excess NO-N from the water column at similar and significantly higher rates than unvegetated treatments, the high denitrification rates observed for cutgrass highlight the potential for permanent removal of excess N from agricultural runoff in vegetated ditches and wetlands. PMID:26437112

  20. How culture gets embrained: Cultural differences in event-related potentials of social norm violations.

    PubMed

    Mu, Yan; Kitayama, Shinobu; Han, Shihui; Gelfand, Michele J

    2015-12-15

    Humans are unique among all species in their ability to develop and enforce social norms, but there is wide variation in the strength of social norms across human societies. Despite this fundamental aspect of human nature, there has been surprisingly little research on how social norm violations are detected at the neurobiological level. Building on the emerging field of cultural neuroscience, we combine noninvasive electroencephalography (EEG) with a new social norm violation paradigm to examine the neural mechanisms underlying the detection of norm violations and how they vary across cultures. EEG recordings from Chinese and US participants (n = 50) showed consistent negative deflection of event-related potential around 400 ms (N400) over the central and parietal regions that served as a culture-general neural marker of detecting norm violations. The N400 at the frontal and temporal regions, however, was only observed among Chinese but not US participants, illustrating culture-specific neural substrates of the detection of norm violations. Further, the frontal N400 predicted a variety of behavioral and attitudinal measurements related to the strength of social norms that have been found at the national and state levels, including higher culture superiority and self-control but lower creativity. There were no cultural differences in the N400 induced by semantic violation, suggesting a unique cultural influence on social norm violation detection. In all, these findings provided the first evidence, to our knowledge, for the neurobiological foundations of social norm violation detection and its variation across cultures. PMID:26621713

  1. Monitoring the Effects of Acupoint Antioxidant Intervention by Measuring Electrical Potential Difference along the Meridian

    PubMed Central

    Xu, Ming-Ming; Guo, Jing-Ke; Xu, Jin-Sen; Zhang, Chao-Xin; Liu, Shu-Tao; Liao, Ri-Tao; Lin, Chun-Tong; Guo, Jian-Hui; Rao, Ping-Fan

    2015-01-01

    Previous studies suggest that superoxide anions are possibly traveling along acupuncture meridians. The electrical potential difference (EPD) between acupoints may be related to the movement. To test the above hypothesis, we conducted a study investigating the effects of acupoint antioxidant interventions on the meridian EPD. Firstly, ST39 (L) and ST44 (L) were screened out for the EPD detection along the stomach meridian, and ST36 (L) was selected for interventions including acumassage with the control cream, as well as the TAT-SOD cream for 30 minutes, or injection with reduced glutathione sodium. The EPD between ST39 and ST44 was recorded for 80 minutes and measured again 48 h later. While the EPD increased during the acumassage, the acumassage with TAT-SOD cream and the glutathione injection generated waves of EPD increased, indicating the migration or removal from the visceral organ of a greater quantity of superoxide. Remarkably lower EPD readings 48 h later with both antioxidant acupoint interventions than the mere acumassage imply a more complete superoxide flushing out due to the restored superoxide pathway at the acupoint after interventions. The results confirm superoxide transportation along the meridians and demonstrate a possibility of acupoint EPD measurement as a tool to monitor changes in the meridians and acupoints. PMID:25861356

  2. Prebiotic potential of Agave angustifolia Haw fructans with different degrees of polymerization.

    PubMed

    Velzquez-Martnez, Jos Rodolfo; Gonzlez-Cervantes, Rina M; Hernndez-Gallegos, Minerva Aurora; Mendiola, Roberto Campos; Aparicio, Antonio R Jimnez; Ocampo, Martha L Arenas

    2014-01-01

    Inulin-type fructans are the most studied prebiotic compounds because of their broad range of health benefits. In particular, plants of the Agave genus are rich in fructans. Agave-derived fructans have a branched structure with both ?-(2?1) and ?-(2?6) linked fructosyl chains attached to the sucrose start unit with a degree of polymerization (DP) of up to 80 fructose units. The objective of this work was to assess the prebiotic potential of three Agave angustifolia Haw fructan fractions (AFF) with different degrees of polymerization. The three fructan fractions were extracted from the agave stem by lixiviation and then purified by ultrafiltration and ion exchange chromatography: AFF1, AFF2 and AFF3 with high (3-60 fructose units), medium (2-40) and low (2-22) DP, respectively. The fructan profile was determined with high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), which confirmed a branched fructan structure. Structural elucidation was performed by Fourier Transform Infra-Red Spectroscopy. The AFF spectrum shows characteristic fructan bands. The prebiotic effect of these fractions was assessed in vitro through fermentation by Bifidobacterium and Lactobacillus strains. Four growth patterns were observed. Some bacteria did not grow with any of the AFF, while other strains grew with only AFF3. Some bacteria grew according to the molecular weight of the AFF and some grew indistinctly with the three fructan fractions. PMID:25153877

  3. An exploratory study of a finite difference method for calculating unsteady transonic potential flow

    NASA Technical Reports Server (NTRS)

    Bennett, R. M.; Bland, S. R.

    1979-01-01

    A method for calculating transonic flow over steady and oscillating airfoils was developed by Isogai. The full potential equation is solved with a semi-implicit, time-marching, finite difference technique. Steady flow solutions are obtained from time asymptotic solutions for a steady airfoil. Corresponding oscillatory solutions are obtained by initiating an oscillation and marching in time for several cycles until a converged periodic solution is achieved. The method is described in general terms and results for the case of an airfoil with an oscillating flap are presented for Mach numbers 0.500 and 0.875. Although satisfactory results are obtained for some reduced frequencies, it is found that the numerical technique generates spurious oscillations in the indicial response functions and in the variation of the aerodynamic coefficients with reduced frequency. These oscillations are examined with a dynamic data reduction method to evaluate their effects and trends with reduced frequency and Mach number. Further development of the numerical method is needed to eliminate these oscillations.

  4. Microscopy and Cathodoluminescence Spectroscopy Characterization of Quartz Exhibiting Different Alkali-Silica Reaction Potential.

    PubMed

    Kuchařová, Aneta; Götze, Jens; Šachlová, Šárka; Pertold, Zdeněk; Přikryl, Richard

    2016-02-01

    Different quartz types from several localities in the Czech Republic and Sweden were examined by polarizing microscopy combined with cathodoluminescence (CL) microscopy, spectroscopy, and petrographic image analysis, and tested by use of an accelerated mortar bar test (following ASTM C1260). The highest alkali-silica reaction potential was indicated by very fine-grained chert, containing significant amounts of fine-grained to cryptocrystalline matrix. The chert exhibited a dark red CL emission band at ~640 nm with a low intensity. Fine-grained orthoquartzites, as well as fine-grained metamorphic vein quartz, separated from phyllite exhibited medium expansion values. The orthoquartzites showed various CL of quartz grains, from blue through violet, red, and brown. Two CL spectral bands at ~450 and ~630 nm, with various intensities, were detected. The quartz from phyllite displayed an inhomogeneous dark red CL with two CL spectral bands of low intensities at ~460 and ~640 nm. The massive coarse-grained pegmatite quartz from pegmatite was assessed to be nonreactive and displayed a typical short-lived blue CL (~480 nm). The higher reactivity of the fine-grained hydrothermal quartz may be connected with high concentrations of defect centers, and probably with amorphized micro-regions in the quartz, respectively; indicated by a yellow CL emission (~570 nm). PMID:26790877

  5. Platelet-activating factor relaxes ferret tracheal smooth muscle and reduces transepithelial potential difference in vitro.

    PubMed Central

    Webber, S. E.; Morikawa, T.; Widdicombe, J. G.

    1992-01-01

    1. The effects of platelet activating factor (PAF) were examined on the smooth muscle tone, mucus volume, lysozyme and albumin outputs and potential difference (PD) across the ferret tracheal wall. 2. PAF (0.1-10 microM) had no direct effect on mucus volume, lysozyme or albumin output from the ferret trachea. PAF produced concentration-dependent relaxations of the tracheal smooth muscle and reductions in PD across the tracheal wall. There was no change in the histological appearance of the trachea after exposure to PAF. 3. The PAF-induced smooth muscle relaxation was not affected by FPL55712, a combination of mepyramine and cimetidine, or by a combination of the oxygen free-radical scavengers catalase and superoxide dismutase (SOD); but was abolished by indomethacin or the PAF-receptor antagonist WEB2086. 4. The PAF-induced reduction in PD was not affected by indomethacin, FPL55712 or mepyramine and cimetidine, but was prevented by catalase and SOD, and by WEB2086. 5. We conclude that PAF relaxes ferret tracheal smooth muscle in vitro by receptor-mediated release of a bronchodilator prostaglandin, possibly PGE2. PAF also reduces PD across the trachea suggesting changes in epithelial function; however, there is no histological epithelial damage after PAF. The reduction in PD with PAF is probably produced by receptor-mediated release of oxygen free-radicals. The cellular source of these free-radicals and of the dilator prostaglandin is unclear. PMID:1596685

  6. Ribotypes and virulence gene polymorphisms suggest three distinct Listeria monocytogenes lineages with differences in pathogenic potential.

    PubMed Central

    Wiedmann, M; Bruce, J L; Keating, C; Johnson, A E; McDonough, P L; Batt, C A

    1997-01-01

    A total of 133 Listeria monocytogenes isolates were characterized by ribotyping and allelic analysis of the virulence genes hly, actA, and inlA to uncover linkages between independent phylogenetic and specific virulence markers. PCR-restriction fragment length polymorphisms revealed 8 hly, 11 inl4, and 2 actA alleles. The combination of these virulence gene alleles and ribotype patterns separated L. monocytogenes into three distinct lineages. While distinct hly and inlA alleles were generally found to cluster into these three lineages, actA alleles segregated independently. These three phylogenetic lineages were confirmed when 22 partial actA DNA sequences were analyzed. The clinical history of the L. monocytogenes strains showed evidence for differences in pathogenic potential among the three lineages. Lineage I contains all strains isolated during epidemic outbreaks of listeriosis, while no human isolates were found in lineage III. Animal isolates were found in all three lineages. We found evidence that isolates from lineages I and III have a higher plaquing efficiency than lineage II strains in a cell culture assay. Strains from lineage III also seem to form larger plaques than strains from lineage II. A distinctive ribotype fragment and unique 16S rRNA gene sequences furthermore suggest that lineage III might represent a L. monocytogenes subspecies. None of the 20 human isolates available but 11% of our animal isolates were grouped in this lineage, indicating that strains in this lineage might have reduced virulence for humans. PMID:9199440

  7. How culture gets embrained: Cultural differences in event-related potentials of social norm violations

    PubMed Central

    Mu, Yan; Kitayama, Shinobu; Han, Shihui; Gelfand, Michele J.

    2015-01-01

    Humans are unique among all species in their ability to develop and enforce social norms, but there is wide variation in the strength of social norms across human societies. Despite this fundamental aspect of human nature, there has been surprisingly little research on how social norm violations are detected at the neurobiological level. Building on the emerging field of cultural neuroscience, we combine noninvasive electroencephalography (EEG) with a new social norm violation paradigm to examine the neural mechanisms underlying the detection of norm violations and how they vary across cultures. EEG recordings from Chinese and US participants (n = 50) showed consistent negative deflection of event-related potential around 400 ms (N400) over the central and parietal regions that served as a culture-general neural marker of detecting norm violations. The N400 at the frontal and temporal regions, however, was only observed among Chinese but not US participants, illustrating culture-specific neural substrates of the detection of norm violations. Further, the frontal N400 predicted a variety of behavioral and attitudinal measurements related to the strength of social norms that have been found at the national and state levels, including higher culture superiority and self-control but lower creativity. There were no cultural differences in the N400 induced by semantic violation, suggesting a unique cultural influence on social norm violation detection. In all, these findings provided the first evidence, to our knowledge, for the neurobiological foundations of social norm violation detection and its variation across cultures. PMID:26621713

  8. Shifted excitation Raman difference spectroscopy: a potential tool for outdoor measurements in precision agriculture

    NASA Astrophysics Data System (ADS)

    Maiwald, Martin; Müller, André; Selbeck, Jörn; Käthner, Jana; Zude, Manuela; Fleury, Dominique; Sumpf, Bernd; Erbert, Götz; Tränkle, Günther

    2015-06-01

    In this work we present Shifted Excitation Raman Difference Spectroscopy (SERDS) as a potential spectroscopic tool for outdoor measurements in precision agriculture. A dual-wavelength diode laser at 785 nm is used as an excitation light source which provides an optical power up to 100 mW in cw-operation. Both emission lines for SERDS show single mode operation with a spectral width of <= 11 pm and a spectral distance of about 10 cm-1 over the whole power range. Raman experiments on apples are carried out and show Raman signals from wax layer and β-carotene. Raman investigations under daylight conditions are performed to simulate outdoor measurements. Here, polystyrene (PS) is used as test sample. A broadband signal together with narrow absorption lines of water vapor and Fraunhofer lines of singly ionized calcium (Ca II) mask the Raman lines of PS. Only the strong Raman signal at 999 cm-1 is visible. SERDS efficiently separates the Raman signals of PS from the background signals and a 14-fold improvement of the signal-tobackground noise ratio is achieved.

  9. One-dimensional modeling of a recent Ganga avulsion: Assessing the potential effect of tectonic subsidence on a large river

    NASA Astrophysics Data System (ADS)

    Gupta, Niladri; Kleinhans, Maarten G.; Addink, Elisabeth A.; Atkinson, Peter M.; Carling, Paul A.

    2014-05-01

    River avulsion as studied in small-sized and medium-sized rivers is partly explained by the water surface gradient advantage of a new channel course over the old course, caused by spatial differences in aggradation and compaction. Recently, the effect of meandering upstream of the avulsion node, or bifurcation, was shown to have an equally large effect on avulsion duration as gradient advantage. These effects remain poorly understood for the largest rivers on Earth, where gradients are very small, subtle gradient advantages are affected by tectonics, and often several anabranches remain active simultaneously. Our objective was to assess the relative importance of these factors in the River Ganga in determining the pacing of an avulsion. We used a combination of historical data, remote sensing, and one-dimensional modeling. The course of the Ganga in historical times was through the present Ganga-Bhagirathi system but then there was either a gradual or sudden shift to the present Ganga-Padma system. Historical evidence and remnant paleochannels, as observed in satellite sensor data, corroborate the changing pattern of the Ganga River system, but the exact causes of the shifting and of the short avulsion duration remain unclear. Based on generalized data, using a one-dimensional model we ran idealized scenarios bracketing different tectonic subsidence estimates for long-term morphodynamic evolution of the upstream channel and the two downstream bifurcates. The model predicts flow and sediment partitioning at the bifurcation node, and includes the effect of migrating meanders at the bifurcation and width adjustment of the bifurcates. Our modeling demonstrates that the old and the new branches can remain open' and morphologically active for a long time because of the large backwater effect and the high mobility of the sediment. The bifurcation stabilizes at an asymmetrical flow and sediment division, which in smaller rivers (such as the River Rhine) would be followed by residual channel filling but in the much larger Ganges results in morphologically active anabranches. The model results reveal that neither a gradient advantage nor a bend upstream of the bifurcation leads to an avulsion within centuries as has been observed in some large rivers in tectonically inactive regions. On the other hand, a realistic tectonic uplift of the old branch or subsidence of the new branch may force an avulsion to take place quickly, and historical data show that the study area is seismically active. The combination of these factors leads to a realistic modeled avulsion duration of less than three centuries. Historical data indicate that these general conclusions might also apply to other large rivers in this region, e.g. the Brahmaputra and the Teesta. We conclude that large rivers may avulse quickly in response to tectonics but attain an anabranching pattern because of the large dimension of the residual channel and backwater effects.

  10. Potential effects of climate change on the water level, flora and macro-fauna of a large neotropical wetland.

    PubMed

    beda, Brbara; Di Giacomo, Adrian S; Neiff, Juan Jos; Loiselle, Steven A; Poi, Alicia S Guadalupe; Glvez, Jos ngel; Casco, Silvina; Czar, Andrs

    2013-01-01

    Possible consequences of climate change in one of the world's largest wetlands (Ibera, Argentina) were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a long-term negative trend in water-level. To explore the possible response of biota to such water-level changes, species-area relationships of flora and aerial censuses of macro-fauna were analysed during an extraordinary dry period. Plant species richness at the basin scale was found to be highly resistant to hydrological changes, as the large dimension of the wetland acts to buffer against the water-level variations. However, local diversity decreased significantly with low water levels, leading to the loss of ecosystem resilience to additional stressors. The analysis of macro-fauna populations suggested that wetland provides refuge, in low water periods, for the animals with high dispersal ability (aquatic and migratory birds). On the contrary, the abundance of animals with low dispersal ability (mainly herbivorous species) was negatively impacted in low water periods, probably because they are required to search for alternative resources beyond the wetland borders. This period of resource scarcity was also related to increased mortality of large mammals (e.g. marsh deer) around water bodies with high anthropogenic enrichment and cyanobacteria dominance. The synergy between recurrent climatic fluctuations and additional stressors (i.e. biological invasions, eutrophication) presents an important challenge to the conservation of neotropical wetlands in the coming decades. PMID:23874446

  11. Potential Effects of Climate Change on the Water Level, Flora and Macro-fauna of a Large Neotropical Wetland

    PubMed Central

    Úbeda, Bárbara; Di Giacomo, Adrian S.; Neiff, Juan José; Loiselle, Steven A.; Guadalupe Poi, Alicia S.; Gálvez, José Ángel; Casco, Silvina; Cózar, Andrés

    2013-01-01

    Possible consequences of climate change in one of the world’s largest wetlands (Ibera, Argentina) were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a long-term negative trend in water-level. To explore the possible response of biota to such water-level changes, species-area relationships of flora and aerial censuses of macro-fauna were analysed during an extraordinary dry period. Plant species richness at the basin scale was found to be highly resistant to hydrological changes, as the large dimension of the wetland acts to buffer against the water-level variations. However, local diversity decreased significantly with low water levels, leading to the loss of ecosystem resilience to additional stressors. The analysis of macro-fauna populations suggested that wetland provides refuge, in low water periods, for the animals with high dispersal ability (aquatic and migratory birds). On the contrary, the abundance of animals with low dispersal ability (mainly herbivorous species) was negatively impacted in low water periods, probably because they are required to search for alternative resources beyond the wetland borders. This period of resource scarcity was also related to increased mortality of large mammals (e.g. marsh deer) around water bodies with high anthropogenic enrichment and cyanobacteria dominance. The synergy between recurrent climatic fluctuations and additional stressors (i.e. biological invasions, eutrophication) presents an important challenge to the conservation of neotropical wetlands in the coming decades. PMID:23874446

  12. Spatial and temporal variations in rainfall over Darwin and its vicinity during different large-scale environments

    NASA Astrophysics Data System (ADS)

    Rauniyar, Surendra P.; Walsh, Kevin J. E.

    2016-02-01

    This study analyses the regional variations in rainfall over Darwin and its vicinity due to different large-scale circulations during the Australian summer by utilizing the combination of in situ and C-band polarimetric radar rainfall data at hourly resolution. The eight phases of the Madden-Julian oscillation as defined by Wheeler and Hendon (Mon Weather Rev 132(8):1917-1932, 2004) were used as indicators of different large-scale environments. The analysis found that the large-scale forcing starts to build up from phase 4 by the reversal of low- to mid-level easterly winds to moist westerly winds, reaching a maximum in phase 5 and weakening through phases 6-7. During phases 4-6, most of the study domain experiences widespread rainfall, but with distinct spatial and temporal structures. In addition, during these phases, coastal areas near Darwin receive more rainfall in the early morning (0200-0400 LT) due to the spreading or expansion of rainfall from the Beagle Gulf, explaining the occurrence of a secondary diurnal rainfall peak over Darwin. In contrast, local-scale mechanisms (sea breezes) reinvigorate from phase 8, further strengthening through phases 1-3, when low-level easterly winds become established over Darwin producing rainfall predominately over land and island locations during the afternoon. During these phases, below average rainfall is observed over most of the radar domain, except over the Tiwi Islands in phase 2.

  13. Spatial and temporal variations in rainfall over Darwin and its vicinity during different large-scale environments

    NASA Astrophysics Data System (ADS)

    Rauniyar, Surendra P.; Walsh, Kevin J. E.

    2015-04-01

    This study analyses the regional variations in rainfall over Darwin and its vicinity due to different large-scale circulations during the Australian summer by utilizing the combination of in situ and C-band polarimetric radar rainfall data at hourly resolution. The eight phases of the Madden-Julian oscillation as defined by Wheeler and Hendon (Mon Weather Rev 132(8):1917-1932, 2004) were used as indicators of different large-scale environments. The analysis found that the large-scale forcing starts to build up from phase 4 by the reversal of low- to mid-level easterly winds to moist westerly winds, reaching a maximum in phase 5 and weakening through phases 6-7. During phases 4-6, most of the study domain experiences widespread rainfall, but with distinct spatial and temporal structures. In addition, during these phases, coastal areas near Darwin receive more rainfall in the early morning (0200-0400 LT) due to the spreading or expansion of rainfall from the Beagle Gulf, explaining the occurrence of a secondary diurnal rainfall peak over Darwin. In contrast, local-scale mechanisms (sea breezes) reinvigorate from phase 8, further strengthening through phases 1-3, when low-level easterly winds become established over Darwin producing rainfall predominately over land and island locations during the afternoon. During these phases, below average rainfall is observed over most of the radar domain, except over the Tiwi Islands in phase 2.

  14. A multi-resolution strategy for a multi-objective deformable image registration framework that accommodates large anatomical differences

    NASA Astrophysics Data System (ADS)

    Alderliesten, Tanja; Bosman, Peter A. N.; Sonke, Jan-Jakob; Bel, Arjan

    2014-03-01

    Currently, two major challenges dominate the field of deformable image registration. The first challenge is related to the tuning of the developed methods to specific problems (i.e. how to best combine different objectives such as similarity measure and transformation effort). This is one of the reasons why, despite significant progress, clinical implementation of such techniques has proven to be difficult. The second challenge is to account for large anatomical differences (e.g. large deformations, (dis)appearing structures) that occurred between image acquisitions. In this paper, we study a framework based on multi-objective optimization to improve registration robustness and to simplify tuning for specific applications. Within this framework we specifically consider the use of an advanced model-based evolutionary algorithm for optimization and a dual-dynamic transformation model (i.e. two "non-fixed" grids: one for the source- and one for the target image) to accommodate for large anatomical differences. The framework computes and presents multiple outcomes that represent efficient trade-offs between the different objectives (a so-called Pareto front). In image processing it is common practice, for reasons of robustness and accuracy, to use a multi-resolution strategy. This is, however, only well-established for single-objective registration methods. Here we describe how such a strategy can be realized for our multi-objective approach and compare its results with a single-resolution strategy. For this study we selected the case of prone-supine breast MRI registration. Results show that the well-known advantages of a multi-resolution strategy are successfully transferred to our multi-objective approach, resulting in superior (i.e. Pareto-dominating) outcomes.

  15. Shallow Megathrust Rupture Propagation of Some Large and Giant Earthquakes: Its Tsunami Potential and Identification from Spectral Energy Content

    NASA Astrophysics Data System (ADS)

    Newman, A. V.; Convers, J. A.

    2010-12-01

    Rare, slow-rupturing tsunami earthquakes are known to occur in the shallowest megathrust environment that both slows rupture propagation and enhances tsunami potential, while other megathrust earthquakes remain deeper, rupturing more rapidly and having reduced tsunami potential due to diminished vertical seafloor displacement. However, we postulate that the massive transoceanic tsunamis of some giant earthquakes are caused by total megathrust rupture, where coseismic slip extends beyond the normal seismogenic range, and into the near-trench tsunami earthquake environment. Such ruptures drastically enhance seafloor excitation and causing massive tsunami generation. Examples include the 2004 MW 9.1 Sumatran, the 1964 MW 9.2 Alaskan, and the 1960 MW 9.5 Chile earthquakes. For recent events, the spatial extent of rupture into the near-trench is observable through seismologic modeling of fault rupture, and the distribution of early aftershocks. An ideal case-example supporting this hypothesis is the clear change in shallow rupture behavior between the 2004 MW 9.1 and 2005 MW 8.7 Sumatran earthquakes, with the latter reaming deeper and having only modest tsunami excitation. We find that through examination of the rupture energy of recent very large earthquakes we can identify rupture that pervades the shallow trench by the event’s relative deficiency in high-frequency radiated seismic energy, similar to tsunami earthquakes. Testing both bulk spectral energy ratios, and deviations in the high-frequency energy growth during rupture, we identify the Sumatran 2004 event as deficient, while the 2005 Sumatran and 2010 Chile earthquakes appear in the normal range similar to smaller events, identifying them as having normal megathrust ruptures. Unlike finite-fault modeling using seismic waveforms and imaging of early aftershocks, which can also identify near-trench rupture, earthquake energy determinations can be made in near real-time (often within 10 minutes of rupture initiation), making it a useful tool for rapid tsunami hazard assessment.

  16. Quantity, composition and water contamination potential of ash produced under different wildfire severities.

    PubMed

    Santn, Cristina; Doerr, Stefan H; Otero, Xos L; Chafer, Chris J

    2015-10-01

    Wildfires frequently threaten water quality through the transfer of eroded ash and soil into rivers and reservoirs. The ability to anticipate risks for water resources from wildfires is fundamental for implementing effective fire preparedness plans and post-fire mitigation measures. Here we present a new approach that allows quantifying the amount and characteristics of ash generated under different wildfire severities and its respective water contamination potential. This approach is applied to a wildfire in an Australian dry sclerophyll eucalypt forest, but can be adapted for use in other environments. The Balmoral fire of October 2013 affected 12,694 ha of Sydney's forested water supply catchment. It produced substantial ash loads that increased with fire severity, with 6, 16 and 34 Mg ha(-1) found in areas affected by low, high and extreme fire severity, respectively. Ash bulk density was also positively related to fire severity. The increase with fire severity in the total load and bulk density of the ash generated is mainly attributed to a combination of associated increases in (i) total amount of fuel affected by fire and (ii) contribution of charred mineral soil to the ash layer. Total concentrations of pollutants and nutrients in ash were mostly unrelated to fire severity and relatively low compared to values reported for wildfire ash in other environments (e.g. 4.0-7.3mg As kg(-1); 2.3-4.1 B mg kg(-1); 136-154 P mg kg(-1)). Solubility of the elements analysed was also low, less than 10% of the total concentration for all elements except for B (6-14%) and Na (30-50%). This could be related to a partial loss of soluble components by leaching and/or wind erosion before the ash sampling (10 weeks after the fire and before major ash mobilisation by water erosion). Even with their relatively low concentrations of potential pollutants, the substantial total ash loads found here represent a water contamination risk if transported into the hydrological network during severe erosion events. For example, up to 4 Mg of ash-derived P could be delivered into a single water supply reservoir. PMID:26186138

  17. Interphase potential difference in processes of extraction-reextraction of actinoids and nitric acid using neutral organophosphorus compounds

    NASA Astrophysics Data System (ADS)

    Kondakov, V. M.; Matyukha, V. A.; Semyonov, E. N.

    2003-01-01

    Analysis of the electrochemical phenomena arising in the processes of extraction-reextraction demonstrated that they are followed by interphase potential difference which can reach a few hudreds millivolt. During mass transfer across the phase boundary of the extragent ((C4H9O)3PO, R3PO, [CH3(CH2)7]3N and others in dissolvent) and aqueous solution, potential difference of the same kind as diffusion potentials at the boundary of the solutions with different concentrations and distinguishing movability of the ions opposite charged occur in both phases.

  18. Quaternary megafans, large rivers and other avulsive systems: a potential "who is who" in the geological record

    NASA Astrophysics Data System (ADS)

    Latrubesse, E. M.

    2012-12-01

    A fascinating discussion has been recently calling the attention of sedimentologists and geomorphologists regarding to the dominant fluvial styles preserved in the geological record. While some authors postulate that distributary (or distributive) patterns are the most important systems likely to dominate the alluvial rock record (Weissmann et al.2010, among others) others suggest that a variety of fluvial styles are remarkably preserved in the geological record, rejecting the importance of the distributary systems (such as megafans and other like fans coastal systems) (Fielding et al, 2012 among others). However, the Quaternary record of the largest depositional tracks on Earth has been not assessed in a comparative and detailed way. Here I present results from some of the most important Quaternary areas of sedimentation of the world such as the alluvial belts of the largest rivers, the largest megafans and other impressive fluvial dominated wetlands in active tectonic basins. My study is based on field work I carried out in many of the analyzed areas, a literature review and remote sensing products. Specific examples are discussed from several rivers of the Amazon basin, the Parana River, the Mississippi River, among others. Large depositional tracks in forelands, platforms and intracratonic basins such as the Chaco, the Orinoco Llanos, the Bananal and Pantanal basin, the Ucamara depression, and the Indo-Gangetic plain, which contain a variety of complex avulsive systems and megafans, are discussed. A main conclusion is that megafans and similar distributary systems, avulsive systems with a variety of channel patterns and linear fluvial belts of major rivers, have the potential for preservation in the geological record. The scarcity of purely braided systems in large rivers is noticeable and they are mainly constrained to small-medium size channels, short length piedmont courses or related to relatively small alluvial fans. Meandering and anabranching systems are dominant in large rivers while anabranching systems are characteristic of megarivers. Despite the findings above, a remarkable challenge remains to identify characteristic facies assemblages for reconstructing large rivers, as they are not clearly identified in the geological record. The scale-size limitation of the architectural characteristics of fluvial landforms and the floodplain complexity of large systems are some of the challenges that need additional research when looking for analogs in the sedimentary record. References: Fielding, Christopher R., Ashworth, Philip J., Best, James L., Prokocki, EricW., Smith, Gregory H. Sambrook, (2012). Tributary, distributary and other fluvial patterns: What really represents the norm in the continental rock record?, Sedimentary Geology doi: 10.1016/j.sedgeo.2012.03.004 Weissmann, G.S., Hartley, A.J., Nichols, G.J., Scuderi, L.A., Olson, M., Buehler, H., Banteah, R., 2010. Fluvial form in modern continental sedimentary basins: distributive fluvial systems. Geology 38, 39-42

  19. A large prospective study of meat consumption and colorectal cancer risk: an investigation of potential mechanisms underlying this association.

    PubMed

    Cross, Amanda J; Ferrucci, Leah M; Risch, Adam; Graubard, Barry I; Ward, Mary H; Park, Yikyung; Hollenbeck, Albert R; Schatzkin, Arthur; Sinha, Rashmi

    2010-03-15

    Although the relation between red and processed meat intake and colorectal cancer has been reported in several epidemiologic studies, very few investigated the potential mechanisms. This study examined multiple potential mechanisms in a large U.S. prospective cohort with a detailed questionnaire on meat type and meat cooking methods linked to databases for estimating intake of mutagens formed in meats cooked at high temperatures (heterocyclic amines, polycyclic aromatic hydrocarbons), heme iron, nitrate, and nitrite. During 7 years of follow-up, 2,719 colorectal cancer cases were ascertained from a cohort of 300,948 men and women. The hazard ratios (HR) and 95% confidence intervals (95% CI) comparing the fifth to the first quintile for both red (HR, 1.24; 95% CI, 1.09-1.42; P(trend) < 0.001) and processed meat (HR, 1.16; 95% CI, 1.01-1.32; P(trend) = 0.017) intakes indicated an elevated risk for colorectal cancer. The potential mechanisms for this relation include heme iron (HR, 1.13; 95% CI, 0.99-1.29; P(trend) = 0.022), nitrate from processed meats (HR, 1.16; 95% CI, 1.02-1.32; P(trend) = 0.001), and heterocyclic amine intake [HR, 1.19; 95% CI, 1.05-1.34; P(trend) < 0.001 for 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and HR, 1.17; 95% CI, 1.05-1.29; P(trend) <0.001 for 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx)]. In general, the elevated risks were higher for rectal cancer than for colon cancer, with the exception of MeIQx and DiMeIQx, which were only associated with colon cancer. In conclusion, we found a positive association for red and processed meat intake and colorectal cancer; heme iron, nitrate/nitrite, and heterocyclic amines from meat may explain these associations. PMID:20215514

  20. Contribution of large submarine landslide to tsunami potential in the NE Atlantic region: The Gorringe Bank case study

    NASA Astrophysics Data System (ADS)

    Ramalho, Inês; Omira, Rachid; Baptista, Maria Ana; Miranda, Miguel; Terrinha, Pedro; Batista, Luis; Roque, Cristina

    2015-04-01

    Tsunami is recognized as a natural hazard, and it is now widely accepted that submarine mass-failures are one of possible tsunami sources. Various studies on tsunami-induced by submarine landslides were carried out based on a spontaneous trigger of the mass-failure. In this study we focus on the deep-water submarine landslide in the Gorringe Bank (GB) area, NE Atlantic. In particular, we investigate the contribution of such mass-failure, as an additional source, to tsunami potential. We assume that an initial tsunami is generated by a large earthquake in the south west Iberia margin area that also initiates the failure of the GB landslide. This mass-failure can play the role of a secondary source of tsunami and contribute to tsunami potential. We simulate the tsunami generation as combination between the sea free surface perturbation caused instantaneously by the earthquake and the initial wave generated progressively due to the slide motion. Okada's equations are employed to compute the initial tsunami induced by the earthquake. While, a multi-layers viscous shallow water (VSW) model is used to simulate the flow of the submarine mass failure and the resulting tsunami wave. To model the propagation and coastal impact of the tsunami resulted from a combination of earthquake and landslide, we use a non-linear shallow water model and a nested grid system that allow estimating properly near-shore wave heights and inundation. We consider a 1755-like earthquake of magnitude Mw8.5, and a landslide of an approximate volume of about 60 km3. The characteristics of the landslide come from the analysis of detailed marine geological data including the erosional area (dimensions and scarps) and the seismic profiles. The results are presents in terms of: i) evidences of submarine mass failures in the area of GB; ii) simulations of the slide motion and the resulting tsunami wave; iii) simulations of the tsunami generated by a combination of two triggers: earthquake and landslide; iv) simulations of tsunami propagation and coastal impact; and v) analysis of the contribution of the submarine landslides to tsunami potential in the NE Atlantic. Results show that, using the VSW model for landslide motion, we obtain a good agreement between the sediment deposits simulated and observed. We also find that the submarine mass-failures can significantly contribute to the tsunami hazard in the NE Atlantic region, in particular when they are combined with an initial earthquake-induced tsunami. This work is supported by the FCT project CONDRIBER, Ref. PTDC/GEO-GEO/4430/2012 and ASTARTE - Assessment, Strategy And Risk Reduction for Tsunamis in Europe. Grant 603839, 7th FP (ENV.2013,6,4-3).

  1. A Large-Scale Investigation of Lateralization in Cortical Anatomy and Word Reading: Are There Sex Differences?

    PubMed Central

    Chiarello, Christine; Welcome, Suzanne E.; Halderman, Laura K.; Towler, Stephen; Julagay, Janelle; Otto, Ronald; Leonard, Christiana M.

    2011-01-01

    Although left hemisphere language specialization is one of the most widely reported findings in human neuropsychology, some studies have found evidence for more bilateral language organization in women. We report findings of a large scale, multi-task investigation of sex differences in both structural asymmetries and lateralization of word reading. Two hundred participants were tested in eight divided visual field lexical tasks, and each received a structural MRI scan. We examined whether there was evidence for sex differences in overall measures of neuroanatomical and behavioral lateralization, in specific language tasks and brain regions, and in variation in asymmetry within and across tasks and brain regions. There was very little evidence for sex differences on any behavioral measure. The few indications of sex differences in the current report accounted for 2% or less of the individual variation in asymmetry and could not be replicated in independent subsamples. No sex differences were observed in the asymmetry of structures in Brocas and Wernickes area such as pars triangularis, pars opercularis, the planum temporale, planum parietale, or Heschls gyrus. There were also no sex differences in the variability of neuroanatomical asymmetries within or between brain regions. However, a significant relationship between planum temporale and behavioral asymmetry was restricted to men. PMID:19254094

  2. Anisotropic compositional expansion in elastoplastic materials and corresponding chemical potential: Large-strain formulation and application to amorphous lithiated silicon

    NASA Astrophysics Data System (ADS)

    Levitas, Valery I.; Attariani, Hamed

    2014-09-01

    A general large-strain thermodynamic approach with anisotropic (tensorial) compositional expansion/contraction in elastoplastic material under stress tensor is developed. The dissipation rate due to compositional expansion/contraction is introduced. Adapting and utilizing a previously formulated postulate of realizability, we derived a simple equation for the deviatoric part of the compositional deformation rate. This leads to a nontrivial generalization of the concept and expression for the chemical potential. It receives a contribution from deviatoric stresses, which leads to an increase in the driving force for both the compositional expansion and contraction and to some new phenomena. Our model provides a remarkable description of the known experimental and atomistic simulation data on the biaxial stress evolution during lithiation-delithiation of LixSi on a rigid substrate with just one constant kinetic coefficient. In contrast to known approaches, it does not involve plasticity, because the yield strength is higher than the stresses generated during lithiation-delithiation. This allowed us to suggest a method for reduction in internal stresses by cyclic change in Li concentration with a small amplitude, and our simulations were in qualitative agreement with known experiments. The coupled diffusion and mechanical model was applied to lithiation and delithiation of thin-film, solid, and hollow spherical nanoparticles. The importance of the contribution of the deviatoric stress on the diffusion is demonstrated.

  3. Potential environmental impact of tidal energy extraction in the Pentland Firth at large spatial scales: results of a biogeochemical model

    NASA Astrophysics Data System (ADS)

    van der Molen, J.; Ruardij, P.; Greenwood, N.

    2015-12-01

    A model study was carried out of the potential large-scale (> 100 km) effects of marine renewable tidal energy generation in the Pentland Firth, using the 3-D hydrodynamics-biogeochemistry model GETM-ERSEM-BFM. A realistic 800 MW scenario and an exaggerated academic 8 GW scenario were considered. The realistic 800 MW scenario suggested minor effects on the tides, and undetectable effects on the biogeochemistry. The academic 8 GW scenario suggested effects would be observed over hundreds of kilometres away with changes of up to 10 % in tidal and ecosystem variables, in particular in a broad area in the vicinity of The Wash. There, waters became less turbid, and primary production increased with associated increases in faunal ecosystem variables. Moreover, a one-off increase in carbon storage in the sea bed was detected. Although these first results suggest positive environmental effects, further investigation is recommended of: (i) the residual circulation in the vicinity of the Pentland Firth and effects on larval dispersal using a higher resolution model, (ii) ecosystem effects with (future) state-of-the-art models if energy extraction substantially beyond 1 GW is planned.

  4. Transcriptional and translational mechanisms contribute to regulate the expression of Discs Large 1 protein during different biological processes.

    PubMed

    Marziali, Federico; Cavatorta, Ana Laura; Valdano, Marina Bugnon; Facciuto, Florencia; Gardiol, Daniela

    2015-08-01

    Human discs large (DLG1) has been demonstrated to be involved in cell polarity and maintenance of tissue architecture. However, the mechanisms controlling DLG1 expression are not fully understood. This is relevant as DLG1 is lost during the later stages of malignant progression. We initiated a series of studies to analyse the mechanisms regulating DLG1 expression. We have previously reported the identification of an alternative splicing event in the 5' untranslated region (5'-UTR) of DLG1 mRNA that generates transcripts with two different 5'-UTR (short and large 5'-UTR variants). In this study, we further examined the impact of the DLG1 transcription and the role of the differential expression of the alternative 5'-UTRs on DLG1 protein levels. We analysed these mechanisms during cell processes like differentiation, cell cycle progression and cell-cell contact formation, where the importance of DLG1 activities was previously established. The data presented in this report suggest that the transcriptional regulation of DLG1 strongly contributes to DLG1 abundance and that differential expression of alternative 5'-UTRs with different translational properties, also cooperates, depending on the cell type and cell situation. This study provides new evidence for understanding the transcriptional regulation of DLG1 and the changes in DLG1 expression during different biological processes. PMID:25720117

  5. Observations of Coastal IO Emissions on the Southern Hemisphere and Emission Potential of Different Seaweed Species

    NASA Astrophysics Data System (ADS)

    Horbanski, Martin; Schmitt, Stefan; Frieß, Udo; Pöhler, Denis; Johnston, Paul; Kreher, Karin; Robinson, Andrew D.; Thomas, Alan; Harris, Neil R. P.; Platt, Ulrich

    2014-05-01

    At coastal sites reactive iodine species emitted by seaweed in the intertidal zone during low tide are known to have an important influence on the atmospheric chemistry. However, many underlying mechanisms are presently not understood. Also coastal studies were focused on a few locations on the northern hemisphere and their predominant seaweed species laminaria digitata and ascophyllum nodosum. Therefore the spatial emission and extent of the areas where halogen chemistry is of importance needs to be much better quantified. Especially in the mid latitudes of the southern hemisphere RHS measurements are very sparse. Here we report the first observations of coastal iodine monoxide (IO) in the southern hemisphere during the HALMA/MAORI campaign which was carried out in February to March 2013 on the east coast of New Zealand's South Island at Shag Point located north of Dunedin. To detect IO we used a mobile Open Light Path Cavity Enhanced Differential Optical Absorption Spectroscopy (CE-DOAS) instrument and a stationary Long Path (LP)-DOAS Instrument, which was furthermore used to measure BrO, O3 and I2. The measurement path was positioned over the water and mainly measured air masses that only passes over submerged seaweed forests. With the CE-DOAS placed close to exposed seaweed patches (mainly Macrocystis Pyrifera) we were able to observe high IO mixing ratios of up to 50 ppt (2ppt detection limit). However, the LP-DOAS did not detect IO above the detection limit of 0.7 ppt. This is consistent with previous observations which found that seaweed only emits halogens when exposed to air. To further investigate the emission potential of the seaweed species we setup a Teflon chamber around the CE-DOAS and measured the emissions of five different species for several hours. Additionally the air in the chamber was probed by a compact gas chromatograph (μDIRAC) for measurements of halocarbons and a TEI Ozone monitor. We found very high IO mixing ratios of up to 500 ppt for four seaweed species which correlated with high levels of halocarbons (CH3I, CH2Br2, CH2BrI and CH2BrCl up to 100ppt, CHBr3 up to 600ppt). These results, the similarities and differences in the emission behavior and implications for atmospheric chemistry are discussed.

  6. Comparing the rehydration potential of different milk-based drinks to a carbohydrate-electrolyte beverage.

    PubMed

    Desbrow, Ben; Jansen, Sarah; Barrett, Abby; Leveritt, Michael D; Irwin, Christopher

    2014-12-01

    The aim of this study was to compare the rehydration potential of a carbohydrate-electrolyte beverage with several varieties of milk following exercise-induced fluid losses. Fifteen male participants (age 24.9 ± 5.5 years, height 179.3 ± 4.9 cm, body mass 75.8 ± 6.6 kg (mean ± SD)) lost 2.0% ± 0.2% body mass through intermittent cycling before consuming a different beverage on 4 separate occasions. Drinks included cow's milk (286 kJ·100 mL(-1)), soy milk (273 kJ·100 mL(-1)), a milk-based liquid meal supplement (Sustagen Sport (Nestle); 417 kJ·100 mL(-1)), and a sports drink (Powerade (Coca Cola Ltd); 129 kJ·100 mL(-1)). Beverages were consumed over 1 h in volumes equivalent to 150% of body mass loss. Body mass, blood and urine samples, and measures of gastrointestinal tolerance were obtained before and hourly for 4 h after beverage consumption. Net body mass at the conclusion of each trial was significantly less with Powerade (-1.37 ± 0.3 kg) than with cow's milk (-0.92 ± 0.48 kg), soy milk (-0.78 ± 0.37 kg), and Sustagen Sport (-0.48 ± 0.39 kg). Net body mass was also significantly greater for Sustagen Sport compared with cow's milk trials, but not soy milk. Upon completion of trials, the percentage of beverage retained was Sustagen Sport 65.1% ± 14.7%, soy milk 46.9% ± 19.9%, cow's milk 40.0% ± 24.9%, and Powerade 16.6% ± 16.5%. Changes in plasma volume and electrolytes were unaffected by drink treatment. Subjective ratings of bloating and fullness were higher during all milk trials compared with Powerade whereas ratings of overall thirst were not different between beverages. Milk-based drinks are more effective rehydration options compared with traditional sports drinks. The additional energy, protein, and sodium in a milk-based liquid meal supplement facilitate superior fluid recovery following exercise. PMID:25315686

  7. Large submarine earthquakes that occurred worldwide in a 1-year period (June 2013 to June 2014) - a contribution to the understanding of tsunamigenic potential

    NASA Astrophysics Data System (ADS)

    Omira, R.; Vales, D.; Marreiros, C.; Carrilho, F.

    2015-10-01

    This paper is a contribution to a better understanding of the tsunamigenic potential of large submarine earthquakes. Here, we analyze the tsunamigenic potential of large earthquakes which have occurred worldwide with magnitudes around Mw = 7.0 and greater during a period of 1 year, from June 2013 to June 2014. The analysis involves earthquake model evaluation, tsunami numerical modeling, and sensors' records analysis in order to confirm the generation of a tsunami (or lack thereof) following the occurrence of an earthquake. We also investigate and discuss the sensitivity of tsunami generation to the earthquake parameters recognized to control tsunami occurrence, including the earthquake location, magnitude, focal mechanism and fault rupture depth. Through this analysis, we attempt to understand why some earthquakes trigger tsunamis and others do not, and how the earthquake source parameters are related to the potential of tsunami generation. We further discuss the performance of tsunami warning systems in detecting tsunamis and disseminating the alerts. A total of 23 events, with magnitudes ranging from Mw = 6.7 to Mw = 8.1, have been analyzed. This study shows that about 39 % of the analyzed earthquakes caused tsunamis that were recorded by different sensors with wave amplitudes varying from a few centimeters to about 2 m. Tsunami numerical modeling shows good agreement between simulated waveforms and recorded waveforms, for some events. On the other hand, simulations of tsunami generation predict that some of the events, considered as non-tsunamigenic, caused small tsunamis. We find that most generated tsunamis were caused by shallow earthquakes (depth < 30 km) and thrust faults that took place on/near the subduction zones. The results of this study can help the development of modified and improved versions of tsunami decision matrixes for various oceanic domains.

  8. On the origin of the electrostatic potential difference at a liquid-vacuum interface

    PubMed Central

    Harder, Edward; Roux, Benot

    2008-01-01

    The microscopic origin of the interface potential calculated from computer simulations is elucidated by considering a simple model of molecules near an interface. The model posits that molecules are isotropically oriented and their charge density is Gaussian distributed. Molecules that have a charge density that is more negative toward their interior tend to give rise to a negative interface potential relative to the gaseous phase, while charge densities more positive toward their interior give rise to a positive interface potential. The interface potential for the model is compared to the interface potential computed from molecular dynamics simulations of the nonpolar vacuum-methane system and the polar vacuum-water interface system. The computed vacuum-methane interface potential from a molecular dynamics simulation (?220?mV) is captured with quantitative precision by the model. For the vacuum-water interface system, the model predicts a potential of ?400?mV compared to ?510?mV, calculated from a molecular dynamics simulation. The physical implications of this isotropic contribution to the interface potential is examined using the example of ion solvation in liquid methane. PMID:19102551

  9. Chemical composition and bioethanol potential of different plant species found in pacific northwest conservation buffers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increase in energy demand has led towards considering lignocellulosic feedstocks as potential for ethanol production. Aim of this study was to estimate the potential of grass straws from conservation reserve program (CRP) lands as feedstocks for ethanol production. The CRP was initiated to ensure re...

  10. Comparison of Water Potentials Measured by In Situ Psychrometry and Pressure Chamber in Morphologically Different Species 1

    PubMed Central

    Turner, Neil C.; Spurway, R. A.; Schulze, E.-D.

    1984-01-01

    Leaf water potentials measured by in situ psychrometry were compared with leaf water potentials measured by the pressure chamber technique at various values of water potential in Helianthus annuus, Helianthus nuttallii, Vigna unguiculata, Nerium oleander, Pistacia vera, and Corylus avellana. In V. unguiculata, the leaf water potentials measured by the in situ psychrometer oscillated at the same periodicity as, and proportional to, the leaf conductance. In all species, potentials measured by in situ psychrometers operating in the psychrometric mode were linearly correlated with potentials measured with the pressure chamber. However, the in situ psychrometers underestimated the leaf water potential in the two Helianthus species at low water potentials and overestimated the water potential in P. vera, N. oleander, and C. avellana. The underestimation in the two Helianthus species at low water potentials resulted from differences in water potential across the leaf. The overestimation in P. vera, N. oleander, and C. avellana was considered to arise from low epidermal conductances in these species even after abrasion of the cuticle. Pressure-volume studies with Lycopersicon esculentum showed that less water was expressed from distal than proximal leaflets when the whole leaf was slowly pressurized. The implication of this for water relations characteristics obtained by pressure-volume techniques is discussed. We conclude that in situ psychrometers are suitable for following dynamic changes in leaf water potential, but should be used with caution on leaves with low epidermal conductances. PMID:16663415

  11. Floating potential of a small particle in a plasma: Difference between Maxwellian and Druyvesteyn electron velocity distributions

    SciTech Connect

    Khrapak, Sergey

    2010-10-15

    The floating potential of a small spherical particle immersed in a plasma is calculated for two different electron velocity distributions functions, Maxwellian and Druyvesteyn ones. It is shown that for plasma conditions typical for laboratory gas discharges, the difference between the floating potentials for these two distributions is small, provided the mean energy of the electrons is the same. The obtained results can be useful in the context of complex (dusty) plasmas.

  12. Event-Related Potential Responses to Beloved and Familiar Faces in Different Marriage Styles: Evidence from Mosuo Subjects

    PubMed Central

    Wu, Haiyan; Luo, Li; Dai, Junqiang; Yang, Suyong; Wang, Naiyi; Luo, Yue-jia

    2016-01-01

    Research on familiar face recognition has largely focused on the neural correlates of recognizing a beloved partner or family member. However, no research has explored the effect of marriage style on the recognition of a beloved partner’s face, especially in matriarchal societies. Here, we examined the time course of event-related potentials (ERP) in response to the face of a beloved partner, sibling, or unknown person in a sample of individuals from the matriarchal Mosuo tribe. Two groups were assessed: intermarriage and walking marriage groups (i.e., couples in a committed relationship who do not cohabitate during the daytime). In agreement with previous reports, ERP results revealed more positive VPP, N250, and P300 waveforms for beloved faces than sibling faces in both groups. Moreover, P300 was more positive for beloved partner versus sibling faces; however, this difference emerged at fronto-central sites for the walking marriage group and at posterior sites for the intermarriage group. Overall, we observed that marriage style affects the later stage processing of a beloved partner’s face, and this may be associated with greater affective arousal and familiarity. PMID:26925002

  13. Event-Related Potential Responses to Beloved and Familiar Faces in Different Marriage Styles: Evidence from Mosuo Subjects.

    PubMed

    Wu, Haiyan; Luo, Li; Dai, Junqiang; Yang, Suyong; Wang, Naiyi; Luo, Yue-Jia

    2016-01-01

    Research on familiar face recognition has largely focused on the neural correlates of recognizing a beloved partner or family member. However, no research has explored the effect of marriage style on the recognition of a beloved partner's face, especially in matriarchal societies. Here, we examined the time course of event-related potentials (ERP) in response to the face of a beloved partner, sibling, or unknown person in a sample of individuals from the matriarchal Mosuo tribe. Two groups were assessed: intermarriage and walking marriage groups (i.e., couples in a committed relationship who do not cohabitate during the daytime). In agreement with previous reports, ERP results revealed more positive VPP, N250, and P300 waveforms for beloved faces than sibling faces in both groups. Moreover, P300 was more positive for beloved partner versus sibling faces; however, this difference emerged at fronto-central sites for the walking marriage group and at posterior sites for the intermarriage group. Overall, we observed that marriage style affects the later stage processing of a beloved partner's face, and this may be associated with greater affective arousal and familiarity. PMID:26925002

  14. Calculation of ionization potential and chemical hardness: A comparative study of different methods

    NASA Astrophysics Data System (ADS)

    Shankar, R.; Senthilkumar, K.; Kolandaivel, P.

    The suitability of ab initio and density functional theory (DFT) methods for an accurate determination of ionization potential and chemical hardness is the subject of systematic analysis for a panel of molecules. Comparison of experimental ionization potential values with theoretical results indicates that using orbital energies obtained from the so-called statistical average of orbital potential (SAOP) model exchange correlation potential in Koopman's theorem is an efficient method to evaluate the correct ionization potentials. Experimental ionization potential and electron affinity values have been used to calculate the absolute chemical hardness. Comparative results show that the chemical hardness values calculated by using Hartree-Fock orbital energies in Koopman's theorem are sufficiently good rather than Mller-Plesset second order perturbation method and DFT-generalized gradient approximation (GGA) exchange correlation functional orbital energies. A new method given by Tozer et al. (J Phys Chem A 2005, 109, 8923) to calculate the chemical hardness works well with the orbital energies of DFT-GGA functionals together with the ionization potential values calculated from SAOP orbital energies.

  15. Distinct potential aerosol masses under different scenarios of transport at a suburban site of Beijing.

    PubMed

    Chu, Biwu; Liu, Yongchun; Ma, Qingxin; Ma, Jinzhu; He, Hong; Wang, Gang; Cheng, Shuiyuan; Wang, Xinming

    2016-01-01

    In order to evaluate the secondary aerosol formation potential at a suburban site of Beijing, in situ perturbation experiments in a potential aerosol mass (PAM) reactor were carried out in the winter of 2014. The variations of secondary aerosol formation as a function of time, OH exposure, and the concentrations of gas phase pollutants and particles were reported in this study. Two periods with distinct secondary aerosol formation potentials, marked as Period I and Period II, were identified during the observation. In Period I, the secondary aerosol formation potential was high, and correlated well to the air pollutants, i.e., SO2, NO2, and CO. The maximal secondary aerosol formation was observed with an aging time equivalent to about 3days of atmospheric oxidation. In period II, the secondary aerosol formation potential was low, with no obvious correlation with the air pollutants. Meanwhile, the aerosol mass decreased, instead of showing a peak, with increasing aging time. Backward trajectory analysis during the two periods confirmed that the air mass in Period I was mainly from local sources, while it was attributed mostly to long distance transport in Period II. The air lost its reactivity during the long transport and the particles became highly aged, resulting in a low secondary aerosol formation potential. Our experimental results indicated that the in situ measurement of the secondary aerosol formation potential could provide important information for evaluating the contributions of local emission and long distance transport to the aerosol pollution. PMID:26899644

  16. Systems Perturbation Analysis of a Large-Scale Signal Transduction Model Reveals Potentially Influential Candidates for Cancer Therapeutics

    PubMed Central

    Puniya, Bhanwar Lal; Allen, Laura; Hochfelder, Colleen; Majumder, Mahbubul; Helikar, Tomáš

    2016-01-01

    Dysregulation in signal transduction pathways can lead to a variety of complex disorders, including cancer. Computational approaches such as network analysis are important tools to understand system dynamics as well as to identify critical components that could be further explored as therapeutic targets. Here, we performed perturbation analysis of a large-scale signal transduction model in extracellular environments that stimulate cell death, growth, motility, and quiescence. Each of the model’s components was perturbed under both loss-of-function and gain-of-function mutations. Using 1,300 simulations under both types of perturbations across various extracellular conditions, we identified the most and least influential components based on the magnitude of their influence on the rest of the system. Based on the premise that the most influential components might serve as better drug targets, we characterized them for biological functions, housekeeping genes, essential genes, and druggable proteins. The most influential components under all environmental conditions were enriched with several biological processes. The inositol pathway was found as most influential under inactivating perturbations, whereas the kinase and small lung cancer pathways were identified as the most influential under activating perturbations. The most influential components were enriched with essential genes and druggable proteins. Moreover, known cancer drug targets were also classified in influential components based on the affected components in the network. Additionally, the systemic perturbation analysis of the model revealed a network motif of most influential components which affect each other. Furthermore, our analysis predicted novel combinations of cancer drug targets with various effects on other most influential components. We found that the combinatorial perturbation consisting of PI3K inactivation and overactivation of IP3R1 can lead to increased activity levels of apoptosis-related components and tumor-suppressor genes, suggesting that this combinatorial perturbation may lead to a better target for decreasing cell proliferation and inducing apoptosis. Finally, our approach shows a potential to identify and prioritize therapeutic targets through systemic perturbation analysis of large-scale computational models of signal transduction. Although some components of the presented computational results have been validated against independent gene expression data sets, more laboratory experiments are warranted to more comprehensively validate the presented results. PMID:26904540

  17. Considerations for Probabilistic Analyses to Assess Potential Changes to Large-Break LOCA Definition for ECCS Requirements

    SciTech Connect

    Wilkowski, G.; Rudland, D.; Wolterman, R.; Krishnaswamy, P.; Scott, P.; Rahman, S.; Fairbanks, C.

    2002-07-01

    The U.S.NRC has undertaken a study to explore changes to the body of Part 50 of the U.S. Federal Code of Regulations, to incorporate risk-informed attributes. One of the regulations selected for this study is 10 CFR 50.46, {sup A}cceptance Criteria for Emergency Core Cooling Systems for Light-Water Nuclear Power Reactors{sup .} These changes will potentially enhance safety and reduce unnecessary burden on utilities. Specific attention is being paid to redefining the maximum pipe break size for LB-LOCA by determining the spectrum of pipe diameter (or equivalent opening area) versus failure probabilities. In this regard, it is necessary to ensure that all contributors to probabilistic failures are accounted for when redefining ECCS requirements. This paper describes initial efforts being conducted for the U.S.NRC on redefining the LB-LOCA requirements. Consideration of the major contributors to probabilistic failure, and deterministic aspects for modeling them, are being addressed. At this time three major contributors to probabilistic failures are being considered. These include: (1) Analyses of the failure probability from cracking mechanisms that could involve rupture or large opening areas from either through-wall or surface flaws, whether the pipe system was approved for leak-before-break (LBB) or not. (2) Future degradation mechanisms, such as recent occurrence of PWSCC in PWR piping need to be included. This degradation mechanism was not recognized as being an issue when LBB was approved for many plants or when the initial risk-informed inspection plans were developed. (3) Other indirect causes of loss of pressure-boundary integrity than from cracks in the pipe system also should be included. The failure probability from probabilistic fracture mechanics will not account for these other indirect causes that could result in a large opening in the pressure boundary: i.e., failure of bolts on a steam generator manway, flanges, and valves; outside force damage from the containment building main crane dropping a heavy load on the pipe system when the reactor is in operation; gasket or seal failure; etc. All three major contributors to probabilistic failure need to be considered for redefinition of the LB-LOCA requirements. (authors)

  18. Long-distance abscisic acid signalling under different vertical soil moisture gradients depends on bulk root water potential and average soil water content in the root zone.

    PubMed

    Puértolas, Jaime; Alcobendas, Rosalía; Alarcón, Juan J; Dodd, Ian C

    2013-08-01

    To determine how root-to-shoot abscisic acid (ABA) signalling is regulated by vertical soil moisture gradients, root ABA concentration ([ABA](root)), the fraction of root water uptake from, and root water potential of different parts of the root zone, along with bulk root water potential, were measured to test various predictive models of root xylem ABA concentration [RX-ABA](sap). Beans (Phaseolus vulgaris L. cv. Nassau) were grown in soil columns and received different irrigation treatments (top and basal watering, and withholding water for varying lengths of time) to induce different vertical soil moisture gradients. Root water uptake was measured at four positions within the column by continuously recording volumetric soil water content (θv). Average θv was inversely related to bulk root water potential (Ψ(root)). In turn, Ψ(root) was correlated with both average [ABA](root) and [RX-ABA](sap). Despite large gradients in θv, [ABA](root) and root water potential was homogenous within the root zone. Consequently, unlike some split-root studies, root water uptake fraction from layers with different soil moisture did not influence xylem sap (ABA). This suggests two different patterns of ABA signalling, depending on how soil moisture heterogeneity is distributed within the root zone, which might have implications for implementing water-saving irrigation techniques. PMID:23387513

  19. Altitude Distribution of the Auroral Acceleration Potential Determined from Cluster Satellite Data at Different Heights

    SciTech Connect

    Marklund, Goeran T.; Sadeghi, Soheil; Karlsson, Tomas; Lindqvist, Per-Arne; Nilsson, Hans; Forsyth, Colin; Fazakerley, Andrew; Lucek, Elizabeth A.; Pickett, Jolene

    2011-02-04

    Aurora, commonly seen in the polar sky, is a ubiquitous phenomenon occurring on Earth and other solar system planets. The colorful emissions are caused by electron beams hitting the upper atmosphere, after being accelerated by quasistatic electric fields at 1-2 R{sub E} altitudes, or by wave electric fields. Although aurora was studied by many past satellite missions, Cluster is the first to explore the auroral acceleration region with multiprobes. Here, Cluster data are used to determine the acceleration potential above the aurora and to address its stability in space and time. The derived potential comprises two upper, broad U-shaped potentials and a narrower S-shaped potential below, and is stable on a 5 min time scale. The scale size of the electric field relative to that of the current is shown to depend strongly on altitude within the acceleration region. To reveal these features was possible only by combining data from the two satellites.

  20. Altitude distribution of the auroral acceleration potential determined from cluster satellite data at different heights.

    PubMed

    Marklund, Gran T; Sadeghi, Soheil; Karlsson, Tomas; Lindqvist, Per-Arne; Nilsson, Hans; Forsyth, Colin; Fazakerley, Andrew; Lucek, Elizabeth A; Pickett, Jolene

    2011-02-01

    Aurora, commonly seen in the polar sky, is a ubiquitous phenomenon occurring on Earth and other solar system planets. The colorful emissions are caused by electron beams hitting the upper atmosphere, after being accelerated by quasistatic electric fields at 1-2 R(E) altitudes, or by wave electric fields. Although aurora was studied by many past satellite missions, Cluster is the first to explore the auroral acceleration region with multiprobes. Here, Cluster data are used to determine the acceleration potential above the aurora and to address its stability in space and time. The derived potential comprises two upper, broad U-shaped potentials and a narrower S-shaped potential below, and is stable on a 5 min time scale. The scale size of the electric field relative to that of the current is shown to depend strongly on altitude within the acceleration region. To reveal these features was possible only by combining data from the two satellites. PMID:21405403

  1. Cytoskeletal stiffness, friction, and fluidity of cancer cell lines with different metastatic potential.

    PubMed

    Coughlin, Mark F; Bielenberg, Diane R; Lenormand, Guillaume; Marinkovic, Marina; Waghorne, Carol G; Zetter, Bruce R; Fredberg, Jeffrey J

    2013-03-01

    We quantified mechanical properties of cancer cells differing in metastatic potential. These cells included normal and H-ras-transformed NIH3T3 fibroblast cells, normal and oncoprotein-overexpressing MCF10A breast cancer cells, and weakly and strongly metastatic cancer cell line pairs originating from human cancers of the skin (A375P and A375SM cells), kidney (SN12C and SN12PM6 cells), prostate (PC3M and PC3MLN4 cells), and bladder (253J and 253JB5 cells). Using magnetic twisting cytometry, cytoskeletal stiffness (g') and internal friction (g?) were measured over a wide frequency range. The dependencies of g' and g? upon frequency were used to determine the power law exponent x which is a direct measure of cytoskeletal fluidity and quantifies where the cytoskeleton resides along the spectrum of solid-like (x=1) to fluid-like (x=2) states. Cytoskeletal fluidity x increased following transformation by H-ras oncogene expression in NIH3T3 cells, overexpression of ErbB2 and 14-3-3-? in MCF10A cells, and implantation and growth of PC3M and 253J cells in the prostate and bladder, respectively. Each of these perturbations that had previously been shown to enhance cancer cell motility and invasion are shown here to shift the cytoskeleton towards a more fluid-like state. In contrast, strongly metastatic A375SM and SN12PM6 cells that disseminate by lodging in the microcirculation of peripheral organs had smaller x than did their weakly metastatic cell line pairs A375P and SN12C, respectively. Thus, enhanced hematological dissemination was associated with decreased x and a shift towards a more solid-like cytoskeleton. Taken together, these results are consistent with the notion that adaptations known to enhance metastatic ability in cancer cell lines define a spectrum of fluid-like versus solid-like states, and the position of the cancer cell within this spectrum may be a determinant of cancer progression. PMID:22961212

  2. A large population of king crabs in Palmer Deep on the west Antarctic Peninsula shelf and potential invasive impacts

    PubMed Central

    Smith, Craig R.; Grange, Laura J.; Honig, David L.; Naudts, Lieven; Huber, Bruce; Guidi, Lionel; Domack, Eugene

    2012-01-01

    Lithodid crabs (and other skeleton-crushing predators) may have been excluded from cold Antarctic continental shelf waters for more than 14 Myr. The west Antarctic Peninsula shelf is warming rapidly and has been hypothesized to be soon invaded by lithodids. A remotely operated vehicle survey in Palmer Deep, a basin 120 km onto the Antarctic shelf, revealed a large, reproductive population of lithodids, providing the first evidence that king crabs have crossed the Antarctic shelf. DNA sequencing and morphology indicate the lithodid is Neolithodes yaldwyni Ahyong & Dawson, previously reported only from Ross Sea waters. We estimate a N. yaldwyni population density of 10 600 km?2 and a population size of 1.55 106 in Palmer Deep, a density similar to lithodid populations of commercial interest around Alaska and South Georgia. The lithodid occurred at depths of more than 850 m and temperatures of more than 1.4C in Palmer Deep, and was not found in extensive surveys of the colder shelf at depths of 430725 m. Where N. yaldwyni occurred, crab traces were abundant, megafaunal diversity reduced and echinoderms absent, suggesting that the crabs have major ecological impacts. Antarctic Peninsula shelf waters are warming at approximately 0.01C yr?1; if N. yaldwyni is currently limited by cold temperatures, it could spread up onto the shelf (400600 m depths) within 12 decades. The Palmer Deep N. yaldwyni population provides an important model for the potential invasive impacts of crushing predators on vulnerable Antarctic shelf ecosystems. PMID:21900324

  3. Estimating the Potential Impacts of Large Mesopredators on Benthic Resources: Integrative Assessment of Spotted Eagle Ray Foraging Ecology in Bermuda

    PubMed Central

    Ajemian, Matthew J.; Powers, Sean P.; Murdoch, Thaddeus J. T.

    2012-01-01

    Declines of large sharks and subsequent release of elasmobranch mesopredators (smaller sharks and rays) may pose problems for marine fisheries management as some mesopredators consume exploitable shellfish species. The spotted eagle ray (Aetobatus narinari) is the most abundant inshore elasmobranch in subtropical Bermuda, but its predatory role remains unexamined despite suspected abundance increases and its hypothesized specialization for mollusks. We utilized a combination of acoustic telemetry, benthic invertebrate sampling, gut content analysis and manipulative experiments to assess the impact of spotted eagle rays on Bermudian shellfish resources. Residency and distribution of adult spotted eagle rays was monitored over two consecutive summers in Harrington Sound (HS), an enclosed inshore lagoon that has historically supported multiple recreational and commercial shellfish species. Telemetered rays exhibited variable fidelity (depending on sex) to HS, though generally selected regions that supported relatively high densities of potential mollusk prey. Gut content analysis from rays collected in HS revealed a diet of mainly bivalves and a few gastropods, with calico clam (Macrocallista maculata) representing the most important prey item. Manipulative field and mesocosm experiments with calico clams suggested that rays selected prey patches based on density, though there was no evidence of rays depleting clam patches to extirpation. Overall, spotted eagle rays had modest impacts on local shellfish populations at current population levels, suggesting a reduced role in transmitting cascading effects from apex predator loss. However, due to the strong degree of coupling between rays and multiple protected mollusks in HS, ecosystem-based management that accounts for ray predation should be adopted. PMID:22802956

  4. Estimating the potential impacts of large mesopredators on benthic resources: integrative assessment of spotted eagle ray foraging ecology in Bermuda.

    PubMed

    Ajemian, Matthew J; Powers, Sean P; Murdoch, Thaddeus J T

    2012-01-01

    Declines of large sharks and subsequent release of elasmobranch mesopredators (smaller sharks and rays) may pose problems for marine fisheries management as some mesopredators consume exploitable shellfish species. The spotted eagle ray (Aetobatus narinari) is the most abundant inshore elasmobranch in subtropical Bermuda, but its predatory role remains unexamined despite suspected abundance increases and its hypothesized specialization for mollusks. We utilized a combination of acoustic telemetry, benthic invertebrate sampling, gut content analysis and manipulative experiments to assess the impact of spotted eagle rays on Bermudian shellfish resources. Residency and distribution of adult spotted eagle rays was monitored over two consecutive summers in Harrington Sound (HS), an enclosed inshore lagoon that has historically supported multiple recreational and commercial shellfish species. Telemetered rays exhibited variable fidelity (depending on sex) to HS, though generally selected regions that supported relatively high densities of potential mollusk prey. Gut content analysis from rays collected in HS revealed a diet of mainly bivalves and a few gastropods, with calico clam (Macrocallista maculata) representing the most important prey item. Manipulative field and mesocosm experiments with calico clams suggested that rays selected prey patches based on density, though there was no evidence of rays depleting clam patches to extirpation. Overall, spotted eagle rays had modest impacts on local shellfish populations at current population levels, suggesting a reduced role in transmitting cascading effects from apex predator loss. However, due to the strong degree of coupling between rays and multiple protected mollusks in HS, ecosystem-based management that accounts for ray predation should be adopted. PMID:22802956

  5. Balance and Strength - Estimating the Maximum Prey-Lifting Potential of the Large Predatory Dinosaur Carcharodontosaurus saharicus.

    PubMed

    Henderson, Donald M; Nicholls, Robert

    2015-08-01

    Motivated by the work of palaeo-art "Double Death (2011)," a biomechanical analysis using three-dimensional digital models was conducted to assess the potential of a pair of the large, Late Cretaceous theropod dinosaur Carcharodontosaurus saharicus to successfully lift a medium-sized sauropod and not lose balance. Limaysaurus tessonei from the Late Cretaceous of South America was chosen as the sauropod as it is more completely known, but closely related to the rebbachisaurid sauropods found in the same deposits with C. saharicus. The body models incorporate the details of the low-density regions associated with lungs, systems of air sacs, and pneumatized axial skeletal regions. These details, along with the surface meshes of the models, were used to estimate the body masses and centers of mass of the two animals. It was found that a 6 t C. saharicus could successfully lift a mass of 2.5 t and not lose balance as the combined center of mass of the body and the load in the jaws would still be over the feet. However, the neck muscles were found to only be capable of producing enough force to hold up the head with an added mass of 424 kg held at the midpoint of the maxillary tooth row. The jaw adductor muscles were more powerful, and could have held a load of 512 kg. The more limiting neck constraint leads to the conclusion that two, adult C. saharicus could successfully lift a L. tessonei with a maximum body mass of 850 kg and a body length of 8.3 m. PMID:25884664

  6. A large survey of Croatian wild mammals for Giardia duodenalis reveals a low prevalence and limited zoonotic potential.

    PubMed

    Beck, Relja; Sprong, Hein; Lucinger, Snjezana; Pozio, Edoardo; Cacci, Simone M

    2011-08-01

    Wild mammals are considered an important source of potentially zoonotic Giardia duodenalis parasites, yet surprisingly little information is available on the actual prevalence and the genetic identity of the species they harbor. A large survey was conducted in Croatia by collecting 832 fecal samples from red deer (Cervus elaphus, n = 374), roe deer (Capreolus capreolus, n = 21), wild boars (Sus scrofa, n = 144), foxes (Vulpes vulpes, n = 66), bears (Ursus arctos, n = 19), wolves (Canis lupus, n = 127), jackals (Canis aureus, n = 8), and hares (Lepus europeus, n = 73). Fecal samples were tested for the presence of Giardia cysts using fluorescent microscopy. The observed prevalence ranged from low (1% in red deer, 1.7% in wild boars, and 4.5% in foxes) to moderate (10% in wolves and 12.5% in jackals) to high (24% in roe deer). No cysts were observed in bears and hares. Polymerase chain reaction was performed on microscopically positive samples to amplify fragments of the small subunit ribosomal gene, the ribosomal 5.8S gene and the two flanking internal transcribed sequences, and the triose phosphate isomerase gene. Sequence analysis showed a predominance of G. duodenalis assemblage A in both ruminants (genotypes A1 and A3) and carnivores (genotype A1). G. duodenalis assemblages B, C, and D, as well as Giardia microti, were also detected in this study. This is the first molecular description of the parasite from the red deer, the wolf, and the jackal. The data point to a minor role of wild mammals as reservoirs of zoonotic assemblages of G. duodenalis, albeit cycling between sylvatic and domestic animals is possible. PMID:21142957

  7. The Structure of Pre-Transitional Protoplanetary Disks. II. Azimuthal Asymmetries, Different Radial Distributions of Large and Small Dust Grains In PDS 70

    NASA Technical Reports Server (NTRS)

    Hashimoto, J.; Tsukagoshi, T.; Brown, J. M.; Dong, R.; Muto, T.; Zhu, Z.; Wisniewski, J.; Ohashi, N.; Kudo, T.; Kusakabe, N.; Abe, L.; Akiyama, E.; Brandner, W.; Brandt, T.; Carson, J.; Currie, T.; Egner, S.; Feldt, M.; Grady, Carol A.; Guyon, O.; Hayano, Y.; Hayashi, M.; Hayashi, S.; Henning, T.; Hodapp, K.; Ishii, M.; Iye, M.; Janson, M.; Kandori, R.; Knapp, G.; Kuzuhara, M.; Kwon, J.; Matsuo, T.; McElwain, M. W.; Mayama, S.

    2015-01-01

    The formation scenario of a gapped disk, i.e., transitional disk, and its asymmetry is still under debate. Proposed scenarios such as disk-planet interaction, photoevaporation, grain growth, anticyclonic vortex, eccentricity, and their combinations would result in different radial distributions of the gas and the small (sub-micron size) and large (millimeter size) dust grains as well as asymmetric structures in a disk. Optical/near-infrared (NIR) imaging observations and (sub-)millimeter interferometry can trace small and large dust grains, respectively; therefore multi-wavelength observations could help elucidate the origin of complicated structures of a disk. Here we report Submillimeter Array observations of the dust continuum at 1.3 mm and CO-12 J = 2 yields 1 line emission of the pre-transitional protoplanetary disk around the solar-mass star PDS 70. PDS 70, a weak-lined T Tauri star, exhibits a gap in the scattered light from its disk with a radius of approx. 65 AU at NIR wavelengths. However, we found a larger gap in the disk with a radius of approx. 80 AU at 1.3 mm. Emission from all three disk components (the gas and the small and large dust grains) in images exhibits a deficit in brightness in the central region of the disk, in particular, the dust disk in small and large dust grains has asymmetric brightness. The contrast ratio of the flux density in the dust continuum between the peak position to the opposite side of the disk reaches 1.4. We suggest the asymmetries and different gap radii of the disk around PDS 70 are potentially formed by several (unseen) accreting planets inducing dust filtration.

  8. The Structure of Pre-transitional Protoplanetary Disks. II. Azimuthal Asymmetries, Different Radial Distributions of Large and Small Dust Grains in PDS 70

    NASA Astrophysics Data System (ADS)

    Hashimoto, J.; Tsukagoshi, T.; Brown, J. M.; Dong, R.; Muto, T.; Zhu, Z.; Wisniewski, J.; Ohashi, N.; kudo, T.; Kusakabe, N.; Abe, L.; Akiyama, E.; Brandner, W.; Brandt, T.; Carson, J.; Currie, T.; Egner, S.; Feldt, M.; Grady, C. A.; Guyon, O.; Hayano, Y.; Hayashi, M.; Hayashi, S.; Henning, T.; Hodapp, K.; Ishii, M.; Iye, M.; Janson, M.; Kandori, R.; Knapp, G.; Kuzuhara, M.; Kwon, J.; Matsuo, T.; McElwain, M. W.; Mayama, S.; Mede, K.; Miyama, S.; Morino, J.-I.; Moro-Martin, A.; Nishimura, T.; Pyo, T.-S.; Serabyn, G.; Suenaga, T.; Suto, H.; Suzuki, R.; Takahashi, Y.; Takami, M.; Takato, N.; Terada, H.; Thalmann, C.; Tomono, D.; Turner, E. L.; Watanabe, M.; Yamada, T.; Takami, H.; Usuda, T.; Tamura, M.

    2015-01-01

    The formation scenario of a gapped disk, i.e., transitional disk, and its asymmetry is still under debate. Proposed scenarios such as disk-planet interaction, photoevaporation, grain growth, anticyclonic vortex, eccentricity, and their combinations would result in different radial distributions of the gas and the small (sub-μm size) and large (millimeter size) dust grains as well as asymmetric structures in a disk. Optical/near-infrared (NIR) imaging observations and (sub-)millimeter interferometry can trace small and large dust grains, respectively; therefore multi-wavelength observations could help elucidate the origin of complicated structures of a disk. Here we report Submillimeter Array observations of the dust continuum at 1.3 mm and 12CO J = 2 → 1 line emission of the pre-transitional protoplanetary disk around the solar-mass star PDS 70. PDS 70, a weak-lined T Tauri star, exhibits a gap in the scattered light from its disk with a radius of ~65 AU at NIR wavelengths. However, we found a larger gap in the disk with a radius of ~80 AU at 1.3 mm. Emission from all three disk components (the gas and the small and large dust grains) in images exhibits a deficit in brightness in the central region of the disk, in particular, the dust disk in small and large dust grains has asymmetric brightness. The contrast ratio of the flux density in the dust continuum between the peak position to the opposite side of the disk reaches 1.4. We suggest the asymmetries and different gap radii of the disk around PDS 70 are potentially formed by several (unseen) accreting planets inducing dust filtration.

  9. THE STRUCTURE OF PRE-TRANSITIONAL PROTOPLANETARY DISKS. II. AZIMUTHAL ASYMMETRIES, DIFFERENT RADIAL DISTRIBUTIONS OF LARGE AND SMALL DUST GRAINS IN PDS 70 {sup ,}

    SciTech Connect

    Hashimoto, J.; Wisniewski, J.; Tsukagoshi, T.; Brown, J. M.; Dong, R.; Muto, T.; Zhu, Z.; Ohashi, N.; Kudo, T.; Egner, S.; Guyon, O.; Kusakabe, N.; Akiyama, E.; Abe, L.; Brandner, W.; Carson, J.; Feldt, M.; Brandt, T.; Currie, T.; Grady, C. A.; and others

    2015-01-20

    The formation scenario of a gapped disk, i.e., transitional disk, and its asymmetry is still under debate. Proposed scenarios such as disk-planet interaction, photoevaporation, grain growth, anticyclonic vortex, eccentricity, and their combinations would result in different radial distributions of the gas and the small (sub-μm size) and large (millimeter size) dust grains as well as asymmetric structures in a disk. Optical/near-infrared (NIR) imaging observations and (sub-)millimeter interferometry can trace small and large dust grains, respectively; therefore multi-wavelength observations could help elucidate the origin of complicated structures of a disk. Here we report Submillimeter Array observations of the dust continuum at 1.3 mm and {sup 12}CO J = 2 → 1 line emission of the pre-transitional protoplanetary disk around the solar-mass star PDS 70. PDS 70, a weak-lined T Tauri star, exhibits a gap in the scattered light from its disk with a radius of ∼65 AU at NIR wavelengths. However, we found a larger gap in the disk with a radius of ∼80 AU at 1.3 mm. Emission from all three disk components (the gas and the small and large dust grains) in images exhibits a deficit in brightness in the central region of the disk, in particular, the dust disk in small and large dust grains has asymmetric brightness. The contrast ratio of the flux density in the dust continuum between the peak position to the opposite side of the disk reaches 1.4. We suggest the asymmetries and different gap radii of the disk around PDS 70 are potentially formed by several (unseen) accreting planets inducing dust filtration.

  10. Potential impact of atmospheric N deposition on soil N2O emission varies with different soil N regimes

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Yi, M.; Koike, T.

    2011-12-01

    Future increases in nitrogen (N) deposition has the potential to change belowground nutrient dynamics, especially N cycle, and thereby can alter the soil-atmosphere exchange of nitrous oxide (N2O) which is one of the major greenhouse gases. Moreover, we considered that their effect on soil N2O emission varies with different soil N levels because N2O is a by-product of the biological nitrification process in aerobic soil environments and of the biological denitrification process in anaerobic soil environments. To understand the changes in soil N2O flux under different soil N, we carried out simulated N addition experiment in three-year-old hybrid larch F1 (F1: Larix gmelinii var. japonica × Larix kaempferi) plantation during two growing seasons 2008 - 2009. The hybrid larch F1 was developed to make up for several problems of larch species, e.g. a high susceptibility to disease or grazing damage by insects and fungi, and a large number of this seedlings are planted recently in northern Japan. Based on soil analysis, we selected two sites which have different soil N concentration, i.e. low-N and high-N concentrations. Nitrogen input was initiated at the onset of our experiment, and included four treatments with four replications: Low-N soil + Zero-N control, Low-N soil + 50 kg-N addition, High-N soil + Zero-N control and High-N soil + 50 kg-N addition. The N was added as ammonium nitrate (NH4NO3) solution distributed in four occasions during each growing season. Gas and soil samples were taken from each plot on ten occasions at a time during each growing season. Collected N2O concentrations were determined by a gas chromatograph (GC-14B; Shimadzu, Kyoto, Japan) equipped with an electron capture detector, while total-N and inorganic-N concentrations were obtained by a NC analyzer (Sumigraph NC-1000; Sumica Chemical Analysis Service Ltd., Osaka, Japan) and an auto analyzer (AACS-4; BL-TEC Inc., Osaka, Japan), respectively. Before the N addition, initial total-N in High-N soil was almost two times higher than that of Low-N soil, but there were no significant differences in physical soil properties among four treatments, e.g. bulk density and water-filled pore space. During the measurement period, N addition increased NH4-N and NO3-N concentrations (P < 0.01), and therefore stimulated soil N2O emissions from 50 kg-N addition plots in both soil N regimes (P < 0.05). Furthermore, increased levels of soil N2O flux in High-N soil were higher than that of Low-N soil (P < 0.001). In this study, we found a positive spatial relationship between soil N2O emission and NO3-N concentration (R2 = 0.80, P < 0.0001). Overall, N addition induced emission in High-N soil was equivalent to 1.66% of the applied N. This value is over the IPCC 1.25% default value, but the loss of 0.69% in Low-N soil is considerably lower than the IPCC mean default value. In conclusion, our results suggest that soil N2O emission seems to largely depend on whether the ecosystem N limited or not at the time of N inputs. Nitrogen cycling in forest ecosystems, which already exhibits large N2O emission, responded strongly to the added N, where as an ecosystem that has been limited by N uses up the added N rapidly and soil N2O emission was elevated only for a short term.

  11. [Application of a potential difference to evaluate the absorptive faculty in the small intestine. The changes in potential differences, uptake of sugars and amino acid and electrical transmural resistance in injured intestine].

    PubMed

    Ohkohchi, N; Kasai, M; Ohi, R; Igarashi, Y; Naganuma, H

    1985-12-01

    Since there was no effective method for evaluating the absorptive capacity in the small intestine, we devised a test for evaluating the absorptive capacity with potential difference. Potential difference is provided by electrical resistance of intestine and flux of substances. Previously, we reported that the electrical resistance of the small intestine in the guinea pigs had changed very slightly throughout the entire life, and that sugars and neutral amino acids have been transported completely activity from the birth. In addition, potential difference of glycyl-glycine reflected the uptake of the intestine after the period of weanling. We experimentally studied the electrical transmural resistance and absorptive capacity of the small intestine with various damages to the small intestine by 5-Fu, ischemia and long fasting. Histologically, swelling of nucleus, intracellular edema, dilatation of capillary vein, dropping of epithelial cells, etc., were seen in these models. But the electrical resistance was slightly changed in 10% of the cases. Potential differences by sugars or neutral amino acid ingestion accurately reflected their real flux. These facts suggest that the potential differences deficiently reflect the uptake of sugars and amino acids in the small intestine under conditions with malabsorption. PMID:4088187

  12. Large regional differences in incidence of arthroscopic meniscal procedures in the public and private sector in Denmark

    PubMed Central

    Hare, Kristoffer Borbjerg; Vinther, Jesper Heg; Lohmander, L Stefan; Thorlund, Jonas Bloch

    2015-01-01

    Objectives A recent study reported a large increase in the number of meniscal procedures from 2000 to 2011 in Denmark. We examined the nation-wide distribution of meniscal procedures performed in the private and public sector in Denmark since different incentives may be present and the use of these procedures may differ from region to region. Setting We included data on all patients who underwent an arthroscopic meniscal procedure performed in the public or private sector in Denmark. Participants Data were retrieved from the Danish National Patient Register on patients who underwent arthroscopic meniscus surgery as a primary or secondary procedure in the years 2000 to 2011. Hospital identification codes enabled linkage of performed procedures to specific hospitals. Primary and secondary outcome measures Yearly incidence of meniscal procedures per 100?000 inhabitants was calculated with 95% CIs for public and private procedures for each region. Results Incidence of meniscal procedures increased at private and at public hospitals. The private sector accounted for the largest relative and absolute increase, rising from an incidence of 1 in 2000 to 98 in 2011. In 2011, the incidence of meniscal procedures was three times higher in the Capital Region than in Region Zealand. Conclusions Our study identified a large increase in the use of meniscal procedures in the public and private sector in Denmark. The increase was particularly conspicuous in the private sector as its proportion of procedures performed increased from 1% to 32%. Substantial regional differences were present in the incidence and trend over time of meniscal procedures. PMID:25712820

  13. Influence of apoE content on receptor binding of large, bouyant LDL in subjects with different LDL subclass phenotypes.

    PubMed

    Barbagallo, C M; Levine, G A; Blanche, P J; Ishida, B Y; Krauss, R M

    1998-03-01

    We investigated the influence of apolipoprotein (apo) E-containing particles on LDL receptor binding of large, buoyant LDL subfractions (LDL I) from subjects with predominantly large (phenotype A) and small (phenotype B) LDL particles. Direct binding by human fibroblast LDL receptors was tested at 4 degrees C before and after removal of apoE-containing particles by immunoaffinity chromatography. The binding affinity of total LDL I in phenotype B was greater than that in phenotype A (Kd of 1.83+/-0.3 and 3.43+/-0.9 nmol/L, respectively, P<.05). LDL I from phenotype B subjects had a higher apoE to apoB molar ratio than did that from phenotype A (0.16+/-0.04 versus 0.06+/-0.02, P<.05). Nondenaturing gradient gel electrophoresis of apoE-containing LDL I isolated by immunoaffinity chromatography revealed a substantially larger peak particle diameter than in apoE-free LDL I, and comparison of LDL I composition before and after immunoaffinity chromatography suggested an increase in triglyceride content of apoE-containing particles. After removal of these particles, there was a greater than twofold reduction in LDL receptor affinity of phenotype B LDL (Kd of 1.83+/-0.3 to 3.76+/-0.6, P<.01), whereas in phenotype A no change was observed (Kd of 3.43+/-0.9 to 3.57+/-0.4, respectively). The receptor affinity of apoE-free LDL I from phenotype A and B subjects did not differ. These findings confirm that large, buoyant LDL particles from phenotype B subjects have a higher LDL receptor affinity than does LDL I from phenotype A subjects and suggest that this difference is due to an increased content of large, triglyceride-enriched, apoE-containing lipoproteins. It is possible that the accumulation of these particles reflects abnormalities in the metabolism of remnant lipoproteins that contribute to atherosclerosis risk in phenotype B subjects. PMID:9514416

  14. Copy number variation detection in cattle reveals potential breed specific differences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copy Number Variations (CNVs) are large, common deletions or duplications of genome sequence among individuals of a species that have been linked to diseases and phenotypic traits. For example, a CNV-generating, translocation mechanism encompassing the KIT gene is responsible for color sidedness in ...

  15. Evaluation of the Potential Environmental Impacts from Large-Scale Use and Production of Hydrogen in Energy and Transportation Applications

    SciTech Connect

    Wuebbles, D.J.; Dubey, M.K., Edmonds, J.; Layzell, D.; Olsen, S.; Rahn, T.; Rocket, A.; Wang, D.; Jia, W.

    2010-06-01

    The purpose of this project is to systematically identify and examine possible near and long-term ecological and environmental effects from the production of hydrogen from various energy sources based on the DOE hydrogen production strategy and the use of that hydrogen in transportation applications. This project uses state-of-the-art numerical modeling tools of the environment and energy system emissions in combination with relevant new and prior measurements and other analyses to assess the understanding of the potential ecological and environmental impacts from hydrogen market penetration. H2 technology options and market penetration scenarios will be evaluated using energy-technology-economics models as well as atmospheric trace gas projections based on the IPCC SRES scenarios including the decline in halocarbons due to the Montreal Protocol. Specifically we investigate the impact of hydrogen releases on the oxidative capacity of the atmosphere, the long-term stability of the ozone layer due to changes in hydrogen emissions, the impact of hydrogen emissions and resulting concentrations on climate, the impact on microbial ecosystems involved in hydrogen uptake, and criteria pollutants emitted from distributed and centralized hydrogen production pathways and their impacts on human health, air quality, ecosystems, and structures under different penetration scenarios

  16. Relative stability of different DNA guanine quadruplex stem topologies derived using large-scale quantum-chemical computations

    PubMed Central

    Šponer, Jiří; Mládek, Arnošt; Špačková, Nad’a; Cang, Xiaohui; Cheatham, Thomas E.; Grimme, Stefan

    2013-01-01

    We provide theoretical predictions of the intrinsic stability of different arrangements of guanine quadruplex (G-DNA) stems. Most computational studies of nucleic acids have applied Molecular Mechanics (MM) approaches using simple pairwise-additive force fields. The principle limitation of such calculations is the highly approximate nature of the force fields. In this study we for the first time apply accurate QM computations (DFT-D3 with large atomic orbital basis sets) to essentially complete DNA building blocks, namely, seven different folds of the cation-stabilized 2-quartet G-DNA stem, each having more than 250 atoms. The solvent effects are approximated by COSMO continuum solvent. We reveal sizeable differences between MM and QM descriptions of relative energies of different G-DNA stems, which apparently reflect approximations of the DNA force field. Using the QM energy data, we propose correction to earlier free energy estimates of relative stabilities of different parallel, hybrid and antiparallel G-stem folds based on classical simulations. The new energy ranking visibly improves the agreement between theory and experiment. We predict the 5′-anti-anti-3′ GpG dinucleotide step to be the most stable one, closely followed by the 5′-syn-anti-3′ step. The results are in good agreement with known experimental structures of 2, 3 and 4-quartet G-DNA stems. Besides providing specific results for G-DNA, our study highlights basic limitations of force field modeling of nucleic acids. Although QM computations have their own limitations, mainly the lack of conformational sampling and the approximate description of the solvent, they can substantially improve quality of calculations currently relying exclusively on force fields. PMID:23742743

  17. Fog Forecasting using Synergy between Models of different Complexity: Large-Eddy Simulation, Column modelling and Limited Area Modelling

    NASA Astrophysics Data System (ADS)

    Steeneveld, G. J.; Masbou, M.; van Heerwaarden, C. C.; Mohr, C.; Schneider, W.; Mller, M.; Bott, A.; Holtslag, A. A. M.

    2010-07-01

    Fog is a hazardous weather phenomenon with a large impact on the environment and human life. In particular the transportation sector is vulnerable to fog; but fog is also important for agriculture, for leaf-wetness duration in particular, and for humans with asthma or related diseases. In addition, fog and low level clouds govern to a large extent the radiation balance of the polar regions in summer, and as such fog also influences the regional climate. Hence a thorough understanding of the fog governing processes is essential. However, due to the complexity and small scale nature of the relevant physical processes, the current understanding is relatively poor, as is our ability to forecast fog. In order to improve our knowledge, and to identify key deficiencies in the current state of the art fog forecasting models, we present an experiment in which the synergy between models of different complexity and observations is used to evaluate model skill. Therefore, an observed case study (Cabauw; The Netherlands) of a well developed radiation fog will be innovatively run with a large eddy simulation model which allows us to evaluate the key issue of turbulent mixing. In addition, operational and research column models (PAFOG; Duynkerke, 1991) will be employed to evaluate their skill on the local scale, while at the limited area models WRF-NMMFOG (Mueller et al 2010) and COSMO-FOG will be evaluated on their skill for the regional scale. Special focus will be given to the representation of the boundary-layer vertical structure and turbulence in the latter two model types versus the LES results with its solid physical ground.

  18. Integrating Differences: Design Culture's Potential Impact on Contemporary Education

    ERIC Educational Resources Information Center

    Uri, Therese

    2012-01-01

    This qualitative study charted the implications and potentialities of embracing a design culture within contemporary education. Unlike the positivist scientific paradigm which dissects and analyzes, a design philosophy offers a unifying logic that facilitates change, acknowledges complexity, and shapes possibilities (Nelson & Stolterman,…

  19. Predicting Reading Growth with Event-Related Potentials: Thinking Differently about Indexing "Responsiveness"

    ERIC Educational Resources Information Center

    Lemons, Christopher J.; Key, Alexandra P. F.; Fuchs, Douglas; Yoder, Paul J.; Fuchs, Lynn S.; Compton, Donald L.; Williams, Susan M.; Bouton, Bobette

    2010-01-01

    The purpose of this study was to determine if event-related potential (ERP) data collected during three reading-related tasks (Letter Sound Matching, Nonword Rhyming, and Nonword Reading) could be used to predict short-term reading growth on a curriculum-based measure of word identification fluency over 19 weeks in a sample of 29 first-grade

  20. A modified mirror projection visual evoked potential stimulator for presenting patterns in different orientations.

    PubMed

    Taylor, P K; Wynn-Williams, G M

    1986-07-01

    Modifications to a standard mirror projection visual evoked potential stimulator are described to enable projection of patterns in varying orientations. The galvanometer-mirror assembly is mounted on an arm which can be rotated through 90 degrees. This enables patterns in any orientation to be deflected perpendicular to their axes. PMID:2424725

  1. Integrating Differences: Design Culture's Potential Impact on Contemporary Education

    ERIC Educational Resources Information Center

    Uri, Therese

    2012-01-01

    This qualitative study charted the implications and potentialities of embracing a design culture within contemporary education. Unlike the positivist scientific paradigm which dissects and analyzes, a design philosophy offers a unifying logic that facilitates change, acknowledges complexity, and shapes possibilities (Nelson & Stolterman,

  2. OXIDATION POTENTIALS OF SOIL ORGANIC MATTER IN HISTOSOLS UNDER DIFFERENT TILLAGE METHODS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soils in the Everglades Agricultural Area (EAA) of south Florida, USA are subsiding due primarily to oxidation by aerobic microoganisms. One way to reduce oxidation of soil organic matter is through minimum tillage. An experiment was set up on a Histosol to determine the potentials for oxidation re...

  3. Groundwater pollution potential and greenhouse gas emission from soils amended with different swine biochars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although there exist numerous research studies in the literature on greenhouse gas emission and groundwater pollution potentials of soils amended with plant-based biochar made from traditional dry pyrolysis (hereafter referred as pyrochar), a very few such studies exist for hydrochar made from hydro...

  4. Job Stress in the United Kingdom: Are Small and Medium-Sized Enterprises and Large Enterprises Different?

    PubMed

    Lai, Yanqing; Saridakis, George; Blackburn, Robert

    2015-08-01

    This paper examines the relationships between firm size and employees' experience of work stress. We used a matched employer-employee dataset (Workplace Employment Relations Survey 2011) that comprises of 7182 employees from 1210 private organizations in the United Kingdom. Initially, we find that employees in small and medium-sized enterprises experience lower level of overall job stress than those in large enterprises, although the effect disappears when we control for individual and organizational characteristics in the model. We also find that quantitative work overload, job insecurity and poor promotion opportunities, good work relationships and poor communication are strongly associated with job stress in the small and medium-sized enterprises, whereas qualitative work overload, poor job autonomy and employee engagements are more related with larger enterprises. Hence, our estimates show that the association and magnitude of estimated effects differ significantly by enterprise size. PMID:24302431

  5. Slags in a Large Variation Range of Oxygen Potential Based on the Ion and Molecule Coexistence Theory

    NASA Astrophysics Data System (ADS)

    Yang, Xue-Min; Li, Jin-Yan; Zhang, Meng; Chai, Guo-Min; Zhang, Jian

    2014-12-01

    A thermodynamic model for predicting sulfide capacity of CaO-FeO-Fe2O3-Al2O3-P2O5 slags in a large variation range of oxygen potential corresponding to mass percentage of FetO from 1.88 to 55.50 pct, i.e., IMCT- model, has been developed by coupling with the deduced desulfurization mechanism of the slags based on the ion and molecule coexistence theory (IMCT). The developed IMCT- model has been verified through comparing the determined sulfide capacity after Ban-ya et al.[20] with the calculated by the developed IMCT- model and the calculated by the reported sulfide capacity models such as the KTH model. Mass percentage of FetO as 6.75 pct corresponding to the mass action concentration of FetO as 0.0637 or oxygen partial as 2.27 10-6 Pa is the criterion for distinguishing reducing and oxidizing zones for the slags. Sulfide capacity of the slags in reducing zone is controlled by reaction ability of CaO regardless of slag oxidization ability. However, sulfide capacity of the slags in oxidizing zone shows an obvious increase tendency with the increasing of slag oxidization ability. Sulfide capacity of the slags in reducing zone keeps almost constant with variation of the simplified complex basicity (pct CaO)/((pct Al2O3) + (pct P2O5)), or optical basicity, or the mass action concentration ratios of N FeO/ N CaO, , , and . Sulfide capacity of the slags in oxidizing zone shows an obvious increase with the increasing of the simplified complex basicity (pct CaO)/((pct Al2O3) + (pct P2O5)) or optical basicity, or the aforementioned mass action concentration ratios. Thus, the aforementioned mass action concentration ratios and the corresponding mass percentage ratios of various iron oxides to basic oxide CaO are recommended to represent the comprehensive effect of various iron oxides and basic oxide CaO on sulfide capacity of the slags.

  6. Neurite, a Finite Difference Large Scale Parallel Program for the Simulation of Electrical Signal Propagation in Neurites under Mechanical Loading

    PubMed Central

    García-Grajales, Julián A.; Rucabado, Gabriel; García-Dopico, Antonio; Peña, José-María; Jérusalem, Antoine

    2015-01-01

    With the growing body of research on traumatic brain injury and spinal cord injury, computational neuroscience has recently focused its modeling efforts on neuronal functional deficits following mechanical loading. However, in most of these efforts, cell damage is generally only characterized by purely mechanistic criteria, functions of quantities such as stress, strain or their corresponding rates. The modeling of functional deficits in neurites as a consequence of macroscopic mechanical insults has been rarely explored. In particular, a quantitative mechanically based model of electrophysiological impairment in neuronal cells, Neurite, has only very recently been proposed. In this paper, we present the implementation details of this model: a finite difference parallel program for simulating electrical signal propagation along neurites under mechanical loading. Following the application of a macroscopic strain at a given strain rate produced by a mechanical insult, Neurite is able to simulate the resulting neuronal electrical signal propagation, and thus the corresponding functional deficits. The simulation of the coupled mechanical and electrophysiological behaviors requires computational expensive calculations that increase in complexity as the network of the simulated cells grows. The solvers implemented in Neurite—explicit and implicit—were therefore parallelized using graphics processing units in order to reduce the burden of the simulation costs of large scale scenarios. Cable Theory and Hodgkin-Huxley models were implemented to account for the electrophysiological passive and active regions of a neurite, respectively, whereas a coupled mechanical model accounting for the neurite mechanical behavior within its surrounding medium was adopted as a link between electrophysiology and mechanics. This paper provides the details of the parallel implementation of Neurite, along with three different application examples: a long myelinated axon, a segmented dendritic tree, and a damaged axon. The capabilities of the program to deal with large scale scenarios, segmented neuronal structures, and functional deficits under mechanical loading are specifically highlighted. PMID:25680098

  7. Ab initio calculation of the deformation potential and photoelastic coefficients of silicon with a non-uniform finite-difference solver based on the local density approximation

    NASA Astrophysics Data System (ADS)

    Witzens, Jeremy

    2014-08-01

    The band diagram, deformation potential and photoelastic tensor of silicon are calculated self-consistently under uniaxial and shear strain by solving for the electronic wavefunctions with a finite-difference method. Many-body effects are accounted for by the local density approximation. In order to accommodate the large number of grid points required due to the diverging electrostatic potential near the atomic nuclei in an all-electron calculation, a non-uniform meshing is adopted. Internal displacements are taken into account by adding an additional coordinate transform to the method of Bir and Pikus. Good consistency of the calculated deformation potential and photoelastic coefficients is obtained with prior experimental and theoretical results, validating the numerical methods. Furthermore, it is shown that a slight correction of the multiplicative coefficient of the X? approximation for conduction bands results in good agreement with experiment for both the direct and indirect bandgaps.

  8. Assessment of self-help methods to reduce potential exposure to radiological contamination after a large-scale radiological release.

    PubMed

    Snyder, Emily; Drake, John; Cardarelli, John; Hall, Kathy; Szabo, Jeff; Demmer, Rick; Lindberg, Michael; Riggs, Karen; James, Ryan

    2014-09-01

    After the release of radioactive materials from a large radiological dispersal device (e.g., dirty bomb), improvised nuclear detonation, or nuclear power plant accident, up to hundreds of square miles may be contaminated. A portion of this area will be evacuated; however, people living in the portion that is not evacuated yet is still contaminated with low-levels of radioactive contamination will be asking for ways they can reduce their exposure. Whether cleaning activities can significantly reduce exposure is not fully understood. In this effort, the ability of cleaning activities to remove cesium (137Cs) was studied. The removal efficacy of cleaning with a commercial product, Simple Green, was compared to cleaning with water for hard surfaces typically seen in residences. The removal efficacy of laundering fabric material surfaces was also determined for a range of conditions (e.g., fabric material type, wash temperature). During these studies, assessments of the implications of these activities (e.g., cross-contamination, resulting waste streams) were also completed. Simple Green and water were effective for removing 137Cs from plastic laminate and vinyl flooring (93.4-96.8%) but were not effective for removing 137Cs from painted wallboard and wood (7.3-68.1%). It was also determined that there was no significant difference between the two cleaners on all of the surfaces, except plastic laminate, for which Simple Green was slightly more effective. Laundering was effective for removing 137Cs contamination from polyester and cotton swatches and cotton comforters (up to 96.8% in the single swatch testing). PMID:25068960

  9. [Potential Carbon Fixation Capability of Non-photosynthetic Microbial Community at Different Depth of the South China Sea and Its Response to Different Electron Donors].

    PubMed

    Fang, Feng; Wang, Lei; Xi, Xue-fei; Hu, Jia-jun; Fu, Xiao-hua; Lu, Bing; Xu, Dian-sheng

    2015-05-01

    The seawater samples collected from many different areas with different depth in the South China Sea were cultivated using different electron donors respectively. And the variation in the potential carbon fixation capability ( PCFC ) of non-photosynthetic microbial community (NPMC) in seawater with different depth was determined after a cycle of cultivation through the statistic analysis. In addition, the cause for the variation was clarified through analyzing key gene abundance regarding CO2 fixation and characteristics of seawater with different depth. The result showed that the PCFCs of NPMC in seawater with different depth were generally low and had no significant difference when using NaNO2 as the electron donor. The PCFC of NPMC in surface seawater was higher than that in deep seawater when using H2 as the electron donor, on the contrary, the PCFC of NPMC in deep seawater was higher than that in surface seawater when using Na2S2O3 as the electron donor. The abundance of the main CO2 fixation gene cbbL in surface seawater was higher than that in deep seawater while the cbbM gene abundance in deep seawater was higher than that in surface seawater. Most hydrogen-oxidizing bacteria had the cbbL gene, and most sulfur bacteria had the cbbM gene. The tendency of seawater cbbL/cbbM gene abundance with the change of depth revealed that there were different kinds of bacteria accounting for the majority in NPMC fixing CO2 at different depth of ocean, which led to different response of PCFC of NPMC at different depth of the sea to different electron donors. The distributions of dissolved oxygen and inorganic carbon concentration with the change of the depth of the sea might be an important reason leading to the difference of NPMC structure and even the difference of PCFC at different depth of the sea. PMID:26314099

  10. Assessing the variability of glacier lake bathymetries and potential peak discharge based on large-scale measurements in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Cochachin, Alejo; Huggel, Christian; Salazar, Cesar; Haeberli, Wilfried; Frey, Holger

    2015-04-01

    Over timescales of hundreds to thousands of years ice masses in mountains produced erosion in bedrock and subglacial sediment, including the formation of overdeepenings and large moraine dams that now serve as basins for glacial lakes. Satellite based studies found a total of 8355 glacial lakes in Peru, whereof 830 lakes were observed in the Cordillera Blanca. Some of them have caused major disasters due to glacial lake outburst floods in the past decades. On the other hand, in view of shrinking glaciers, changing water resources, and formation of new lakes, glacial lakes could have a function as water reservoirs in the future. Here we present unprecedented bathymetric studies of 124 glacial lakes in the Cordillera Blanca, Huallanca, Huayhuash and Raura in the regions of Ancash, Huanuco and Lima. Measurements were carried out using a boat equipped with GPS, a total station and an echo sounder to measure the depth of the lakes. Autocad Civil 3D Land and ArcGIS were used to process the data and generate digital topographies of the lake bathymetries, and analyze parameters such as lake area, length and width, and depth and volume. Based on that, we calculated empirical equations for mean depth as related to (1) area, (2) maximum length, and (3) maximum width. We then applied these three equations to all 830 glacial lakes of the Cordillera Blanca to estimate their volumes. Eventually we used three relations from the literature to assess the peak discharge of potential lake outburst floods, based on lake volumes, resulting in 3 x 3 peak discharge estimates. In terms of lake topography and geomorphology results indicate that the maximum depth is located in the center part for bedrock lakes, and in the back part for lakes in moraine material. Best correlations are found for mean depth and maximum width, however, all three empirical relations show a large spread, reflecting the wide range of natural lake bathymetries. Volumes of the 124 lakes with bathymetries amount to 0.9 km3 while the volume of all glacial lakes of the Cordillera Blanca ranges between 1.15 and 1.29 km3. The small difference in volume of the large lake sample as compared to the smaller sample of bathymetrically surveyed lakes is due to the large size of the measured lakes. The different distributions for lake volume and peak discharge indicate the range of variability in such estimates, and provides valuable first-order information for management and adaptation efforts in the field of water resources and flood prevention.

  11. Structural Rationalization of a Large Difference in RNA Affinity Despite a Small Difference in Chemistry between Two 2'-O-Modified Nucleic Acid Analogs

    SciTech Connect

    Pattanayek, R.; Sethaphong, L.; Pan, C.; Prhavc, M.; Prakash, T.P.; Manoharan, M.; Egli, M.

    2010-03-08

    Chemical modification of nucleic acids at the 2'-position of ribose has generated antisense oligonucleotides (AONs) with a range of desirable properties. Electron-withdrawing substituents such as 2'-O-[2-(methoxy)ethyl] (MOE) confer enhanced RNA affinity relative to that of DNA by conformationally preorganizing an AON for pairing with the RNA target and by improving backbone hydration. 2'-Substitution of the ribose has also been shown to increase nuclease resistance and cellular uptake via changes in lipophilicity. Interestingly, incorporation of either 2'-O-[2-(methylamino)-2-oxoethyl]- (NMA) or 2'-O-(N-methylcarbamate)-modified (NMC) residues into AONs has divergent effects on RNA affinity. Incorporation of 2'-O-NMA-T considerably improves RNA affinity while incorporation of 2'-O-NMC-T drastically reduces RNA affinity. Crystal structures at high resolution of A-form DNA duplexes containing either 2'-O-NMA-T or 2'-O-NMC-T shed light on the structural origins of the surprisingly large difference in stability given the relatively minor difference in chemistry between NMA and NMC. NMA substituents adopt an extended conformation and use either their carbonyl oxygen or amino nitrogen to trap water molecules between phosphate group and sugar. The conformational properties of NMA and the observed hydration patterns are reminiscent of those found in the structures of 2'-O-MOE-modified RNA. Conversely, the carbonyl oxygen of NMC and O2 of T are in close contact, providing evidence that an unfavorable electrostatic interaction and the absence of a stable water structure are the main reasons for the loss in thermodynamic stability as a result of incorporation of 2'-O-NMC-modified residues.

  12. Traumatic brain injury and hemorrhagic shock: evaluation of different resuscitation strategies in a large animal model of combined insults.

    PubMed

    Jin, Guang; DeMoya, Marc A; Duggan, Michael; Knightly, Thomas; Mejaddam, Ali Y; Hwabejire, John; Lu, Jennifer; Smith, William Michael; Kasotakis, Georgios; Velmahos, George C; Socrate, Simona; Alam, Hasan B

    2012-07-01

    Traumatic brain injury (TBI) and hemorrhagic shock (HS) are the leading causes of trauma-related mortality and morbidity. Combination of TBI and HS (TBI + HS) is highly lethal, and the optimal resuscitation strategy for this combined insult remains unclear. A critical limitation is the lack of suitable large animal models to test different treatment strategies. We have developed a clinically relevant large animal model of TBI + HS, which was used to evaluate the impact of different treatments on brain lesion size and associated edema. Yorkshire swine (42-50 kg) were instrumented to measure hemodynamic parameters and intracranial pressure. A computer-controlled cortical impact device was used to create a TBI through a 20-mm craniotomy: 15-mm cylindrical tip impactor at 4 m/s velocity, 100-ms dwell time, and 12-mm penetration depth. Volume-controlled hemorrhage was started (40% blood volume) concurrent with the TBI. After 2 h of shock, animals were randomized to one of three resuscitation groups (n = 5/group): (a) normal saline (NS); (b) 6% hetastarch, Hextend (Hex); and (c) fresh frozen plasma (FFP). Volumes of Hex and FFP matched the shed blood, whereas NS was three times the volume. After 6 h of postresuscitation monitoring, brains were sectioned into 5-mm slices and stained with TTC (2,3,5-triphenyltetrazolium chloride) to quantify the lesion size and brain swelling. Combination of 40% blood loss with cortical impact and a period of shock (2 h) resulted in a highly reproducible brain injury. Total fluid requirements were lower in the Hex and FFP groups. Lesion size and brain swelling in the FFP group (2,160 202.63 mm and 22% 1.0%, respectively) were significantly smaller than those in the NS group (3,285 130.8 mm3 and 37% 1.6%, respectively) (P < 0.05). Hex treatment decreased the swelling (29% 1.6%) without reducing the lesion size. Early administration of FFP reduces the size of brain lesion and associated swelling in a large animal model of TBI + HS. In contrast, artificial colloid (Hex) decreases swelling without reducing the actual size of the brain lesion. PMID:22575994

  13. New strategy for drug discovery by large-scale association analysis of molecular networks of different species.

    PubMed

    Zhang, Bo; Fu, Yingxue; Huang, Chao; Zheng, Chunli; Wu, Ziyin; Zhang, Wenjuan; Yang, Xiaoyan; Gong, Fukai; Li, Yuerong; Chen, Xiaoyu; Gao, Shuo; Chen, Xuetong; Li, Yan; Lu, Aiping; Wang, Yonghua

    2016-01-01

    The development of modern omics technology has not significantly improved the efficiency of drug development. Rather precise and targeted drug discovery remains unsolved. Here a large-scale cross-species molecular network association (CSMNA) approach for targeted drug screening from natural sources is presented. The algorithm integrates molecular network omics data from humans and 267 plants and microbes, establishing the biological relationships between them and extracting evolutionarily convergent chemicals. This technique allows the researcher to assess targeted drugs for specific human diseases based on specific plant or microbe pathways. In a perspective validation, connections between the plant Halliwell-Asada (HA) cycle and the human Nrf2-ARE pathway were verified and the manner by which the HA cycle molecules act on the human Nrf2-ARE pathway as antioxidants was determined. This shows the potential applicability of this approach in drug discovery. The current method integrates disparate evolutionary species into chemico-biologically coherent circuits, suggesting a new cross-species omics analysis strategy for rational drug development. PMID:26912056

  14. New strategy for drug discovery by large-scale association analysis of molecular networks of different species

    PubMed Central

    Zhang, Bo; Fu, Yingxue; Huang, Chao; Zheng, Chunli; Wu, Ziyin; Zhang, Wenjuan; Yang, Xiaoyan; Gong, Fukai; Li, Yuerong; Chen, Xiaoyu; Gao, Shuo; Chen, Xuetong; Li, Yan; Lu, Aiping; Wang, Yonghua

    2016-01-01

    The development of modern omics technology has not significantly improved the efficiency of drug development. Rather precise and targeted drug discovery remains unsolved. Here a large-scale cross-species molecular network association (CSMNA) approach for targeted drug screening from natural sources is presented. The algorithm integrates molecular network omics data from humans and 267 plants and microbes, establishing the biological relationships between them and extracting evolutionarily convergent chemicals. This technique allows the researcher to assess targeted drugs for specific human diseases based on specific plant or microbe pathways. In a perspective validation, connections between the plant Halliwell-Asada (HA) cycle and the human Nrf2-ARE pathway were verified and the manner by which the HA cycle molecules act on the human Nrf2-ARE pathway as antioxidants was determined. This shows the potential applicability of this approach in drug discovery. The current method integrates disparate evolutionary species into chemico-biologically coherent circuits, suggesting a new cross-species omics analysis strategy for rational drug development. PMID:26912056

  15. Individual differences in personality profiles among potential living kidney transplant donors

    PubMed Central

    Rodríguez-Marín, Jesús; Martínez-Zaragoza, Fermín; de Santiago-Guervós, Carlos

    2013-01-01

    Background: Although the psychological assessment of potential living kidney donors (PLKD) is part of the recommendations for action for any transplant coordination, there are not many studies that provide data about the importance of selecting donors for improving transplant outcomes. This work aims to raise awareness of potential kidney donors by designing methods for early detection of potential problems after the transplant, as well as by selecting the most suitable donors. Methods: This is a study of 25 PLKD drawn from the General University Hospital of Alicante. Participants completed the Millon Clinical Multiaxial Inventory (MCMI-III) for the study of personality characteristics. Results: Women scored higher than men in the compulsive personality scale, and individuals with a genetic link with the recipient scored higher on depressive and dependent scales than did those with other relationships (emotional or altruistic). Conclusions: Women showed a pattern of significantly more compulsive personality traits (cautious, controlled, perfectionist) within a non-pathological style. Among the PLKD, there were significantly more women, which is contrary to what typically happens with donations from cadavers. Genetically related subjects scored higher on depression than did those that were emotionally related. The personality assessment of candidates for PLKD can help with developing a post-transplant follow-up regimen for an improved quality of life. PMID:24892237

  16. MEDICARE’S BUNDLED PAYMENTS FOR CARE IMPROVEMENT (BPCI) INITIATIVE: EXPANDING ENROLLMENT SUGGESTS POTENTIAL FOR LARGE IMPACT

    PubMed Central

    Chen, Lena M.; Meara, Ellen; Birkmeyer, John D.

    2015-01-01

    Objectives Aiming to encourage care coordination and cost-efficiency, the Center for Medicare & Medicaid Innovation (CMMI) launched the Bundled Payments for Care Improvement (BPCI) initiative in 2013. To help gauge the program’s potential impact and generalizability, we describe early and current participants. Study Design We examined the cross-sectional association between BPCI participation and providers’ structural and cost characteristics. Methods Using data from October 2013 and June 2014, we quantified changes in BPCI participation. We described structural differences between participating and non-participating hospitals using t-tests and chi-square tests. We used the Cochrane-Armitage test to assess whether participants were more likely be in higher 90-day episode cost quintiles than their peers at baseline (2009–2010). Results Overall (risk-bearing and non-risk-bearing) participation in BPCI increased six-fold from 417 (October 2013) to 2,597 (June 2014), attributable in part to Model 2, the most comprehensive model. Model 2 hospitals increasingly resemble eligible but non-participating hospitals. For the most commonly chosen condition of hip replacement, Model 2 hospitals were not costlier than their peers. Hospitals used to make up 97% of Model 2 participants, but physician practices now comprise half. However, most BPCI participants have not yet begun to bear financial risk. Risk-bearing Model 2 hospitals are a smaller and less representative group, with higher baseline costs for hip replacement than their peers. Conclusions Growing participation in BPCI suggests strong interest in bundled payments. The long-term impact of BPCI will depend on CMMI’s ability to persuade interested but non-risk-bearing participants to bear risk. PMID:26633254

  17. On measuring instruments for space plasma electron component parameters in the presence of 'plasma-body' potential difference

    NASA Astrophysics Data System (ADS)

    Chapkunov, S. K.

    Instrumentation designs are presented which have been used on payloads of the vertical series of ionosphere sounding rockets to measure the electrical potentials of the space plasma surrounding the spacecraft. The basic design is a Langmuir probe, comprising a current-voltage converter (CVC), a cylindrical probe collector (CPC), a telemetry system and a sawtooth voltage generator (SVG). A recent design upgrade is an automatic control for the variation range of the sweep voltage applied to the CPC. The variation is performed with the SVG as a function of the potential difference between the body of the spacecraft relative to the surrounding space plasma. A block diagram is provided of the necessary circuitry for obtaining the automated voltage variations for the probe. The probe potential is adjusted to match the potential of the environment, and the matching potential data is telemetered back to the ground station.

  18. Numerical study on the potential impact of different bottom boundary conditions on the water balance of lysimeters

    NASA Astrophysics Data System (ADS)

    Groh, Jannis; Vanderborght, Jan; Ptz, Thomas; Vereecken, Harry

    2014-05-01

    The SOILCan lysimeter network is a large scale climate feedback experiment and is embedded in the four long term observatories of TERENO (TERestrial ENvironmental Observatories). The focus of the SOILCan-project is to observe the impact of climate change on water and matter budgets in different grass- and arable-land lysimeters. The monitoring infrastructure was established across a rainfall and temperature transect along which lysimeters were transported from wetter to drier conditions. The lysimeters in SOILCan have a controlled bottom boundary condition using a rack of suction candles that enables upward and downward flow of water. This pressure head at the bottom is controlled by measured soil water potentials in undisturbed soil in the close vicinity of the bottom of the lysimeter. For transported lysimeters this controlling approach no longer works as the surrounding soil profile and both its upper climatic boundary conditions and lower boundary conditions related to its hydrogeological setting differ from the place where the lysimeter was taken from. In order to evaluate these artefacts and to derive a suited approach to control the lower boundary of transported lysimeters, water balance simulations were run. We analyzed three different approaches to impose bottom boundary conditions for transported lysimeters. A 'zeroth-order' approach is to define the bottom boundary at the bottom of the lysimeter and use the pressure heads measured at the location from which the soil lysimeter was taken. However, this approach is prone to artefacts since these bottom boundary conditions are determined by the climate at the site where the lysimeter was taken from. A 'first-order' approach is to define a bottom boundary condition at a certain hydrogeological boundary that can be defined deeper in the soil profile such as a seepage face or a groundwater table. However, for shallow groundwater tables, this approach may also lead to artefacts since the depth of the groundwater table may change with changing climate. In a 'second-order' approach, the effect of changing climate conditions on these bottom boundaries is evaluated. Therefore, other hydrogeological properties that determine lateral groundwater flow such as the depth of an impermeably layer and the distance between surface water structures that drain groundwater have to be considered in the approach as well. We will present a comparison of these approaches using water balance results derived by numerical simulation with the software HYDRUS 1-D.

  19. Gastric emptying, esophageal 24-hour pH and gastric potential difference measurements in non-ulcer dyspepsia.

    PubMed

    Pfeiffer, A; Aronbayev, J; Schmidt, T; Wendl, B; Pehl, C; Kaess, H

    1992-01-01

    Pathological gastroesophageal reflux, prolonged gastric emptying and abnormal gastric potential difference have been claimed to be functional disorders often detectable in non-ulcer dyspspsia (NUD). The role of Helicobacter pylori in NUD is still unclear. The aim of the present study was to evaluate the prevalence of these factors in 47 patients with NUD. According to DeMeester's criteria, 60 percent of NUD patients had abnormal gastroesophageal reflux, while 38 percent had prolonged gastric emptying of a liquid meal. Seventy-nine percent showed abnormal gastric potential difference which was unrelated to Helicobacter pylori colonization, detected in 46 percent of NUD patients. When esophageal pHmetry, gastric emptying evaluation and measurement of gastric potential difference were performed, 89 percent of NUD patients presented at least one abnormal finding. PMID:1526393

  20. How to hierarchize the main physiological processes responsible for phenotypic differences in large-scale screening studies?

    PubMed Central

    Moreau, Delphine; Salon, Christophe; Munier-Jolain, Nathalie

    2012-01-01

    One difficulty when analyzing the determinants at the origin of plant phenotypic differences is that measured plant traits are frequently integrative: they result from the integration of a large number of physiological processes under the control of genetic and environmental factors. In a previous report, we demonstrated that dissecting integrative traits into simpler components using a simple crop physiology model was a valuable method for detecting quantitative trait loci (QTL) related to the nitrogen nutrition for a recombinant inbred lines population of Medicago truncatula.7 Here, using the same data set, we demonstrate the relevance of decomposing integrative traits for understanding biological differences among phenotypes, independently of QTL detection. Two examples are given to demonstrate that the dissection of integrative traits (i.e., plant leaf area and nitrogen nutrition index) into variables representing the efficiency of the plant to extract and valorize (carbon and nitrogen) resources is an effective method to determine the stream of physiological events that leads to the final phenotype. PMID:22499204

  1. Time-scale and extent at which large-scale circulation modes determine the wind and solar potential in the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Jerez, Sonia; Trigo, Ricardo M.

    2013-12-01

    The North Atlantic Oscillation (NAO), the East Atlantic (EA) and the Scandinavian (SCAND) modes are the three main large-scale circulation patterns driving the climate variability of the Iberian Peninsula. This study assesses their influence in terms of solar (photovoltaic) and wind power generation potential (SP and WP) and evaluates their skill as predictors. For that we use a hindcast regional climate simulation to retrieve the primary meteorological variables involved, surface solar radiation and wind speed. First we identify that the maximum influence of the various modes occurs on the interannual variations of the monthly mean SP and WP series, being generally more relevant in winter. Second we find that in this time-scale and season, SP (WP) varies up to 30% (40%) with respect to the mean climatology between years with opposite phases of the modes, although the strength and the spatial distribution of the signals differ from one month to another. Last, the skill of a multi-linear regression model (MLRM), built using the NAO, EA and SCAND indices, to reconstruct the original wintertime monthly series of SP and WP was investigated. The reconstructed series (when the MLRM is calibrated for each month individually) correlate with the original ones up to 0.8 at the interannual time-scale. Besides, when the modeled series for each individual month are merged to construct an October-to-March monthly series, and after removing the annual cycle in order to account for monthly anomalies, these correlate 0.65 (0.55) with the original SP (WP) series in average. These values remain fairly stable when the calibration and reconstruction periods differ, thus supporting up to a point the predictive potential of the method at the time-scale assessed here.

  2. Potential enhanced ability of giant squid to detect sperm whales is an exaptation tied to their large body size.

    PubMed

    Schmitz, Lars; Motani, Ryosuke; Oufiero, Christopher E; Martin, Christopher H; McGee, Matthew D; Wainwright, Peter C

    2013-01-01

    It has been hypothesized that sperm whale predation is the driver of eye size evolution in giant squid. Given that the eyes of giant squid have the size expected for a squid this big, it is likely that any enhanced ability of giant squid to detect whales is an exaptation tied to their body size. Future studies should target the mechanism behind the evolution of large body size, not eye size. Reconstructions of the evolutionary history of selective regime, eye size, optical performance, and body size will improve the understanding of the evolution of large eyes in large ocean animals. PMID:24127991

  3. Hydraulic conductance and soil water potential at the soil-root interface of Pinus pinaster seedlings inoculated with different dikaryons of Pisolithus sp.

    PubMed

    Lamhamedi, M S; Bernier, P Y; Andr-Fortin, J

    1992-04-01

    Seedlings of maritime pine (Pinus pinaster Ait.) were inoculated with different dikaryons of Pisolithus sp. from South Africa to determine the influence of extension of the extramatrical phase and diameter of the mycelial strands on water relations parameters including xylem water potential (Psi(x)), soil water potential at the soil-root interface (Psi(s)) and hydraulic conductance (L(p)) during and after a period of water stress. Seedlings inoculated with dikaryons having an extensive extramatrical phase and large diameter mycelial strands showed higher Psi(s) (-2 MPa) during severe water stress than seedlings inoculated with dikaryons producing fine hyphae and sparse extramatrical phases (-3.8 MPa). Seedlings inoculated with strand-forming dikaryons recovered faster from water stress than did non-inoculated seedlings or seedlings inoculated with non-strand-forming dikaryons. Architectural aspects of the extramatrical phase, including the presence of large diameter mycelial strands or fine hyphae, influenced the soil-root contact and the water relations of an inoculated host plant. When water stress was not limiting, the architecture of the extramatrical phase did not have a large effect on Psi(s). It is suggested that the architecture of the extramatrical phase influences the resistance to water flow through the soil-root interface and that large mycelial strands increase the water flow by bridging the gap between the soil and the root. These changes in physiology indicate that dikaryons can improve the survival of Pinus pinaster under dry conditions. PMID:14969981

  4. Potential explanation of limb combination performance differences for two-limb coordination tasks

    PubMed Central

    Nakagawa, Kento; Muraoka, Tetsuro; Kanosue, Kazuyuki

    2015-01-01

    Rhythmic two-limb coordinated movements in the sagittal plane are variable and inaccurate when the movements are in the opposite direction as compared with those in the same direction (directional constraint). The magnitude of directional constraint depends on the particular limb combination. It is prominent in ipsilateral hand-foot coordination, but minimal in bimanual hand coordination. The reason for such differences remains unclear. In this study, we investigated the possible mechanisms underlying the production of the difference that depend on limb combination. Subjects performed two-limb rhythmic coordinated movements either in the same or in the opposite direction for three separate limb combinations (bilateral hands, contralateral hand and foot, and ipsilateral hand and foot). For each combination two different tasks were performed. In the first condition, subjects actively moved two limbs (active condition). Second, subjects actively moved one limb in coordination with a passively moved limb (passive condition). In the active condition, the directional constraint was dependent upon the limb combination, as reported in previous studies; the directional constraint was quite prominent in ipsilateral combinations, intermediate in contralateral combinations, and minimal for bilateral combination. However, differences in the directional constraint did not depend on limb combination for any combination in the passive conditions which apparently utilized closed-loop control. In other word, the difference depending on limb combination disappeared when control strategies become uniformly closed-loop. Thus, we speculate that the control strategy utilized depends on limb combination in the active condition. Additionally, different mechanisms other than closed-loop control also would have influence depending on the particular limb combination. This may result in differences in performance depending upon the limb combination. PMID:25713327

  5. Age differences in the Attention Network Test: Evidence from behavior and event-related potentials.

    PubMed

    Williams, Ryan S; Biel, Anna Lena; Wegier, Pete; Lapp, Leann K; Dyson, Benjamin J; Spaniol, Julia

    2016-02-01

    The Attention Network Test (ANT) is widely used to capture group and individual differences in selective attention. Prior behavioral studies with younger and older adults have yielded mixed findings with respect to age differences in three putative attention networks (alerting, orienting, and executive control). To overcome the limitations of behavioral data, the current study combined behavioral and electrophysiological measures. Twenty-four healthy younger adults (aged 18-29years) and 24 healthy older adults (aged 60-76years) completed the ANT while EEG data were recorded. Behaviorally, older adults showed reduced alerting, but did not differ from younger adults in orienting or executive control. Electrophysiological components related to alerting and orienting (P1, N1, and CNV) were similar in both age groups, whereas components related to executive control (N2 and P3) showed age-related differences. Together these results suggest that comparisons of network effects between age groups using behavioral data alone may not offer a complete picture of age differences in selective attention, especially for alerting and executive control networks. PMID:26760449

  6. The reactive oxidant potential of different types of aged atmospheric particles: An outdoor chamber study

    NASA Astrophysics Data System (ADS)

    Rattanavaraha, Weruka; Rosen, Eli; Zhang, Haofei; Li, Qianfeng; Pantong, Karun; Kamens, Richard M.

    2011-07-01

    The reactive oxygen species (ROS) potential of aged diesel exhaust particulate matter (PM) and other aged aerosol systems in the presence and absence of an urban hydrocarbon environment was assessed. Experiments were performed in a 274 m 3 dual outdoor Teflon film chamber. Filter samples were taken to assess the oxidant generation associated with PM by an optimized dithiothreitol (DTT) method. Diesel exhaust PM had a higher ROS response when it was in the presence of an urban hydrocarbon mixture and was associated with significant O 3 production. For all the aged dilute diesel systems, ROS expression increased by a factor of 2-4 over fresh diesel particles. Other particle systems were also investigated. A low ROS was observed in most of the nighttime experiments, including the nighttime aerosols from SO 2 with O 3 and SO 2 aged by itself. However, when all the systems were compared, aged diesel exhaust tended to express very high ROS potentials, with secondary organic aerosols from an ?-pinene + toluene + an urban HC mixture giving the highest ROS response.

  7. [Comparative hygienic assessment of potential risk to workers under application of fungicides of different classes].

    PubMed

    Vavrinevych, O P; Omel'chuk, S T; Bardov, V H

    2014-01-01

    The comparative hygienic evaluation of working conditions in various application technologies of triazole fungicides (tebuconazole, dyfenoconazole, penconazole) strobilurine fungicides (azoxystrobin, pyraclostrobin, trifloxystrobin), ethylene-bis-dytiocarbamate fungicides (metiram, mancozeb), cianopyrrole fungicide (fludioxonil), anilide fungicides (benalaxyl-M, boscalid), anilinopirymidyne fungicides (cyprodynil, valifenal, pirymetanil). Potential complex risk of possible harmful effects of the investigated compounds on workers by inhalation and percutaneous admission, as well as a comparative analysis of received values was assessed. Determination of active substances in the samples was carried out by gas-liquid and high performance liquid chromatography. In the air of the working area were found triazoles 0.005-0.01 mg/m3, ethylene-bis-dytiokarbamates--0.01-0.02 mg/m3 at fan plants processing, anilinopirymidynes--0.19 mg/m3 at backpack plants processing. Listed values do not exceed the established hygienic standards in the air of the working area. Steam plants processing had not accompanied by the arrival of investigated compounds in the air of the working area. For all the studied crops processing technologies magnitude of the potential risk of possible harmful effects of study classes fungicides influence at the complex admission does not exceed the permissible level (was less than 1). Comparative analysis of complex risks for workers allowed to distribute fungicides according this criterion in the following order: cianopyrrole < strobilurynes < triazoles < anilides < anilinopirymidynes < ethylene-bis-dytiokarbamates. PMID:25286613

  8. Potential reasons for differences in CAD effectiveness evaluated using laboratory and clinical studies

    NASA Astrophysics Data System (ADS)

    He, Xin; Samuelson, Frank; Zeng, Rongping; Sahiner, Berkman

    2015-03-01

    Research studies have investigated a number of factors that may impact the performance assessment of computer aided detection (CAD) effectiveness, such as the inherent design of the CAD, the image and reader samples, and the assessment methods. In this study, we focused on the effect of prevalence on cue validity (co-occurrence of cue and signal) and learning as potentially important factors in CAD assessment. For example, the prevalence of cases with breast cancer is around 50% in laboratory CAD studies, which is 100 times higher than that in breast cancer screening. Although ROC is prevalence-independent, an observer's use of CAD involves tasks that are more complicated than binary classification, including: search, detection, classification, cueing and learning. We developed models to investigate the potential impact of prevalence on cue validity and the learning of cue validity tasks. We hope this work motivates new studies that investigate previously under-explored factors involved in image interpretation with a new modality in its assessment.

  9. Mitigating the Goldilocks effect: the effects of different substrate models on track formation potential

    PubMed Central

    Falkingham, Peter L.; Hage, Julian; Bker, Martin

    2014-01-01

    In ichnology, the Goldilocks effect describes a scenario in which a substrate must be just right in order for tracks to formtoo soft, the animal will be unable to traverse the area, and too firm, the substrate will not deform. Any given substrate can therefore only preserve a range of tracks from those animals which exert an underfoot pressure at approximately the yield strength of the sediment. However, rarely are substrates vertically homogeneous for any great depth, varying either due to heterogeneity across sediment layers, or from mechanical behaviour such as strain hardening. Here, we explore the specificity of the Goldilocks effect in a number of virtual substrates simulated using finite-element analysis. We find that the inclusion of strain hardening into the model increases the potential range of trackmaker sizes somewhat, compared with a simple elasticperfectly plastic model. The simulation of a vertically heterogeneous, strain hardening substrate showed a much larger range of potential trackmakers than strain hardening alone. We therefore show that the Goldilocks effect is lessened to varying degrees by the inclusion of more realistic soil parameters, though there still remains an upper and lower limit to the size of trackmaker able to traverse the area while leaving footprints. PMID:26064559

  10. Surface potential distribution and airflow performance of different air-exposed electrode plasma actuators at different alternating current/direct current voltages

    SciTech Connect

    Yang, Liang; Yan, Hui-Jie; Qi, Xiao-Hua; Hua, Yue; Ren, Chun-Sheng

    2015-04-15

    Asymmetric surface dielectric barrier discharge (SDBD) plasma actuators have been intensely studied for a number of years due to their potential applications for aerodynamic control. In this paper, four types of actuators with different configurations of exposed electrode are proposed. The SDBD actuators investigated are driven by dual-power supply, referred to as a fixed AC high voltage and an adjustable DC bias. The effects of the electrode structures on the dielectric surface potential distribution, the electric wind velocity, and the mean thrust production are studied, and the dominative factors of airflow acceleration behavior are revealed. The results have shown that the actions of the SDBD actuator are mainly dependent on the geometry of the exposed electrode. Besides, the surface potential distribution can effectively affect the airflow acceleration behavior. With the application of an appropriate additional DC bias, the surface potential will be modified. As a result, the performance of the electric wind produced by a single SDBD can be significantly improved. In addition, the work also illustrates that the actuators with more negative surface potential present better mechanical performance.

  11. Surface potential distribution and airflow performance of different air-exposed electrode plasma actuators at different alternating current/direct current voltages

    NASA Astrophysics Data System (ADS)

    Yang, Liang; Yan, Hui-Jie; Qi, Xiao-Hua; Hua, Yue; Ren, Chun-Sheng

    2015-04-01

    Asymmetric surface dielectric barrier discharge (SDBD) plasma actuators have been intensely studied for a number of years due to their potential applications for aerodynamic control. In this paper, four types of actuators with different configurations of exposed electrode are proposed. The SDBD actuators investigated are driven by dual-power supply, referred to as a fixed AC high voltage and an adjustable DC bias. The effects of the electrode structures on the dielectric surface potential distribution, the electric wind velocity, and the mean thrust production are studied, and the dominative factors of airflow acceleration behavior are revealed. The results have shown that the actions of the SDBD actuator are mainly dependent on the geometry of the exposed electrode. Besides, the surface potential distribution can effectively affect the airflow acceleration behavior. With the application of an appropriate additional DC bias, the surface potential will be modified. As a result, the performance of the electric wind produced by a single SDBD can be significantly improved. In addition, the work also illustrates that the actuators with more negative surface potential present better mechanical performance.

  12. The Difference Between Potential and Achieved Academic Performance of Freshmen Residents at North Carolina State University.

    ERIC Educational Resources Information Center

    Viehe, John Henry

    Differences in academic performance of residents in the various sections and dormitories during the fall semester 1974 at North Carolina State University were studied. Other study objectives were as follows: to develop a methodology to measure academic performance of freshmen residents adjusted for ability, sex, and differential grading…

  13. Problematic Exercise in Anorexia Nervosa: Testing Potential Risk Factors against Different Definitions

    PubMed Central

    Rizk, Melissa; Lalanne, Christophe; Berthoz, Sylvie; Kern, Laurence; Godart, Nathalie

    2015-01-01

    “Hyperactivity” has a wide prevalence range of 31% to 80% in the anorexia nervosa literature that could be partly due to the plethora of definitions provided by researchers in this field. The purpose of this study was two-fold: 1) To assess the variance across prevalence rates of problematic exercise encountered in patients with anorexia nervosa, in relation to seven different definitions found in the literature. 2) To examine how core eating disorder symptoms and the dimensions of emotional profile are associated with these different definitions and the impact of these definitions on the assessment of patients’ quality of life. Exercise was evaluated in terms of duration, intensity, type and compulsion using a semi-structured questionnaire administered to 180 women suffering from severe anorexia nervosa. Seven different definitions of problematic exercise were identified in the literature: three entailing a single dimension of problematic exercise (duration, compulsion or intensity) and four combining these different dimensions. Emotional profile scores, obsessive-compulsive symptoms, eating disorder symptomatology, worries and concerns about body shape, self-esteem and quality of life were assessed using several established questionnaires. The prevalence of problematic exercise varied considerably from, 5% to 54%, depending on the number of criteria used for its definition. The type and level of eating disorder symptomatology was found to be associated with several definitions of problematic exercise. Surprisingly, a better self-reported quality of life was found among problematic exercisers compared to non-problematic exercisers in three of the definitions. The different definitions of problematic exercise explain the broad prevalence ranges and the conflicting associations generally reported in the literature between problematic exercise and eating disorder-related psychological parameters. There is an urgent need for a valid consensus on the definition of problematic exercise in anorexia nervosa. This will support the development of further research on the etiology and treatment of problematic exercise. PMID:26618359

  14. Problematic Exercise in Anorexia Nervosa: Testing Potential Risk Factors against Different Definitions.

    PubMed

    Rizk, Melissa; Lalanne, Christophe; Berthoz, Sylvie; Kern, Laurence; Godart, Nathalie

    2015-01-01

    "Hyperactivity" has a wide prevalence range of 31% to 80% in the anorexia nervosa literature that could be partly due to the plethora of definitions provided by researchers in this field. The purpose of this study was two-fold: 1) To assess the variance across prevalence rates of problematic exercise encountered in patients with anorexia nervosa, in relation to seven different definitions found in the literature. 2) To examine how core eating disorder symptoms and the dimensions of emotional profile are associated with these different definitions and the impact of these definitions on the assessment of patients' quality of life. Exercise was evaluated in terms of duration, intensity, type and compulsion using a semi-structured questionnaire administered to 180 women suffering from severe anorexia nervosa. Seven different definitions of problematic exercise were identified in the literature: three entailing a single dimension of problematic exercise (duration, compulsion or intensity) and four combining these different dimensions. Emotional profile scores, obsessive-compulsive symptoms, eating disorder symptomatology, worries and concerns about body shape, self-esteem and quality of life were assessed using several established questionnaires. The prevalence of problematic exercise varied considerably from, 5% to 54%, depending on the number of criteria used for its definition. The type and level of eating disorder symptomatology was found to be associated with several definitions of problematic exercise. Surprisingly, a better self-reported quality of life was found among problematic exercisers compared to non-problematic exercisers in three of the definitions. The different definitions of problematic exercise explain the broad prevalence ranges and the conflicting associations generally reported in the literature between problematic exercise and eating disorder-related psychological parameters. There is an urgent need for a valid consensus on the definition of problematic exercise in anorexia nervosa. This will support the development of further research on the etiology and treatment of problematic exercise. PMID:26618359

  15. Genesis, stability and preservation potential of large lateral moraines of Alpine valley glaciers - towards a unifying theory

    NASA Astrophysics Data System (ADS)

    Lukas, S.; Graf, A.; Coray, S.; Schlchter, C.

    2012-04-01

    Lateral moraines are prominent features of glaciated landscapes in high-mountain environments and key landforms in glacier and palaeoclimatic reconstructions, yet, compared to smaller moraines, they have been little studied and several aspects are not well understood. This presentation will present detailed sedimentological results from the lateral moraines of Findelengletscher in SW Switzerland to gain new insights into the formation of these landforms. The lateral moraines studied here stand up to 140 m above the valley floor, are over 3 km long and strongly asymmetrical in cross-profile, with distal slopes between 29-36 and proximal slopes that are commonly 41-64, but locally reach angles of up to 80. Recorded lithofacies comprise loose clast and matrix-supported, stratified diamicts and intercalated sorted sediments in the distal slopes and near the crestline; overconsolidated matrix-supported, massive and weakly stratified diamicts and streaked-out sorted sediment lenses in the core and proximal slopes; and partly intercalated dark-brown layers overlain by loose and consolidated diamicts exposed in near-vertical walls in the proximal flank. These are interpreted as supraglacial debris flow units with intercalated fluvial 'wash' horizons; glaciotectonised and subglacial traction till with boudinaged and streaked-out sediment lenses; and palaeosoils overlain by sediment produced by overtopping of the former moraine surface during a subsequent advance of the glacier. Clast shape analysis and process observations reveal that the dominant mode of transport is subglacial and glaciofluvial, and that the main mode of sediment delivery to the moraines is by debris flows after the material has been transferred from the bed via englacial debris bands and meltout at the surface. This differs from previous studies that found that a supraglacial source was dominant. Sedimentary structures, clast fabric and process observations during the 1979/1980 readvance of Findelengletscher strongly suggest that proximal layers of reworked pre-existing sediments and/or basal traction zone till have been plastered onto the moraine core in several locations, causing a high degree of overconsolidation and strongly-clustered fabric eigenvalues (S1 ? 0.94) with clustering parallel to the moraine crestline. This suggests that a combination of basal-lateral drag and lateral plastering produces the observed proximal stability and ensures a high preservation potential. The data are synthesised into a conceptual model that describes Alpine lateral moraines as structurally complex landforms that do not just record a single event as often surmised; implications for palaeo-glacier reconstruction and the application of numerical dating methods are also discussed.

  16. Strains of the soil fungus Mortierella show different degradation potentials for the phenylurea herbicide diuron.

    PubMed

    Ellegaard-Jensen, Lea; Aamand, Jens; Kragelund, Birthe B; Johnsen, Anders H; Rosendahl, Sren

    2013-11-01

    Microbial pesticide degradation studies have until now mainly focused on bacteria, although fungi have also been shown to degrade pesticides. In this study we clarify the background for the ability of the common soil fungus Mortierella to degrade the phenylurea herbicide diuron. Diuron degradation potentials of five Mortierella strains were compared, and the role of carbon and nitrogen for the degradation process was investigated. Results showed that the ability to degrade diuron varied greatly among the Mortierella strains tested, and the strains able to degrade diuron were closely related. Degradation of diuron was fastest in carbon and nitrogen rich media while suboptimal nutrient levels restricted degradation, making it unlikely that Mortierella utilize diuron as carbon or nitrogen sources. Degradation kinetics showed that diuron degradation was followed by formation of the metabolites 1-(3,4-dichlorophenyl)-3-methylurea, 1-(3,4-dichlorophenyl)urea and an hitherto unknown metabolite suggested to be 1-(3,4-dichlorophenyl)-3-methylideneurea. PMID:23361127

  17. The thermodynamic activity of proline in ternary solutions of different water potentials.

    PubMed

    Pahlich, E; Stadermann, T

    1984-06-01

    The particular colligative properties of proline caused us to investigate the thermodynamic activity of this amino acid in detail. The dependence of the activity coefficients ? of proline (? = thermodynamic activity/molality) on the pH of the solutions, the composition of the solution and the water potential has been measured. The results show that the activity coefficient of proline varies according to the solute milieu. The most pronounced alterations of the activity coefficient could be observed in polyethylene glycol solutions in contrast to KCl- and saccharose solutions where the effect was less distinct. The results described provide a basis for discussing water stress induced metabolic alterations in terms of thermodynamic entities. Changed rates of proline metabolizing sequences and changed ratios of the vacuole/extravacuole distribution of this amino acid in stressed and un-stressed plants may partially be explained by thermodynamic causes. PMID:23196091

  18. Survival of Dermatophilus congolensis in tropical clay soils submitted to different water potentials.

    PubMed

    Martinez, D; Prior, P

    1991-10-01

    The survival of a rifampicin-resistant mutant of Dermatophilus congolensis in vertisol and oxisol soils from Guadeloupe and in their constitutive clays was studied using a pneumatic device for controlling water potentials (pF). Experiments were carried out at two pF values simulating the wet season and the dry season. Survival time depended on the type of soil and its water content. Organic matter had a protective effect on the microorganism in oxisol but not in vertisol. The pathogenicity of D. congolensis was preserved in the soils which could therefore act as temporary reservoirs of this pathogen. Long-term survival of this organism in soils mixed with water suggests that ponds and dipping tanks may constitute sources of infection for cattle. PMID:1746153

  19. EET-dependent potentiation of pulmonary arterial pressure: sex-different regulation of soluble epoxide hydrolase.

    PubMed

    Kandhi, Sharath; Qin, Jun; Froogh, Ghezal; Jiang, Houli; Luo, Meng; Wolin, Michael S; Huang, An; Sun, Dong

    2015-12-15

    We tested the hypothesis that suppression of epoxyeicosatrienoic acid (EET) metabolism via genetic knockout of the gene for soluble epoxide hydrolase (sEH-KO), or female-specific downregulation of sEH expression, plays a role in the potentiation of pulmonary hypertension. We used male (M) and female (F) wild-type (WT) and sEH-KO mice; the latter have high pulmonary EETs. Right ventricular systolic pressure (RVSP) and mean arterial blood pressure (MABP) in control and in response