Sample records for large potential difference

  1. Discussion on the Energy-Saving Potential of a Hybrid System in a Large Space Building in Different Areas

    E-print Network

    Liu, S.; Huang, C.

    2006-01-01

    ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency, Vol. IV-10-5 Discussion on the Energy-Saving Potential of a Hybrid System in a Large Space Building in Different Areas1 Sheng Liu Chen Huang Post-graduated Professor... quality, but also for reducing energy consumption, should be promoted greatly. REFERENCES [1] C Huang, S Liu, W G Huang. Energy-Saving Potential of Upper-Opening in Large Space Building. Proceedings of the 10th International Conference on Indoor...

  2. Large Nc QCD at nonzero chemical potential

    NASA Astrophysics Data System (ADS)

    Cohen, Thomas D.

    2004-12-01

    The general issue of large Nc QCD at nonzero chemical potential is considered with a focus on understanding the difference between large Nc QCD with an isospin chemical potential and large Nc QCD with a baryon chemical potential. A simple diagrammatic analysis analogous to 'tHooft’s analysis at ?=0 implies that the free energy with a given baryon chemical potential is equal to the free energy with an isospin chemical potential of the same value plus 1/Nc corrections. Phenomenologically, these two systems behave quite differently. A scenario to explain this difference in light of the diagrammatic analysis is explored. This scenario is based on a phase transition associated with pion condensation when the isospin chemical potential exceeds m?/2; associated with this transition there is breakdown of the 1/Nc expansion—in the pion condensed phase there is a distinct 1/Nc expansion including a larger set of diagrams. While this scenario is natural, there are a number of theoretical issues which at least superficially challenge it. Most of these can be accommodated. However, the behavior of quenched QCD which raises a number of apparently analogous issues cannot be easily understood completely in terms of an analogous scenario. Thus, the overall issue remains open.

  3. Potentials of large format camera photography

    Microsoft Academic Search

    R. C. Malhotra

    1986-01-01

    From the viewpoint of improved precision, resolution, area coverage, and other terrain mapping considerations, a large format camera of 30-cm focal length and a pair of stellar cameras to determine camera attitude were recommended for Apollo Missions. In this paper, the potentials of a Large Format Camera (LFC) photography are explored specifically for the purpose of carrying out photogrammetic control

  4. Electrical potential difference during laser welding

    NASA Astrophysics Data System (ADS)

    Zohm, H.; Ambrosy, G.; Lackner, K.; Lackner

    2015-01-01

    We present a new model for the generation of thermoelectric currents during laser welding, taking into account sheath effects at both contact points as well as the potential drop within the quasi-neutral plasma generated by the laser. We show that the model is in good agreement with experimentally measured electric potential difference between the hot and the cold parts of the welded workpiece. In particular, all three elements of the model are needed to correctly reproduce the sign of the measured voltage difference. The mechanism proposed relies on the temperature dependence of the electron flux from the plasma to the workpiece and hence does not need thermoemission from the workpiece surface to explain the experimentally observed sign and magnitude of the potential drop.

  5. Potential and issues in large scale flood inundation modelling

    NASA Astrophysics Data System (ADS)

    Di Baldassarre, Giuliano; Brandimarte, Luigia; Dottori, Francesco; Mazzoleni, Maurizio; Yan, Kun

    2015-04-01

    The last years have seen a growing research interest on large scale flood inundation modelling. Nowadays, modelling tools and datasets allow for analyzing flooding processes at regional, continental and even global scale with an increasing level of detail. As a result, several research works have already addressed this topic using different methodologies of varying complexity. The potential of these studies is certainly enormous. Large scale flood inundation modelling can provide valuable information in areas where few information and studies were previously available. They can provide a consistent framework for a comprehensive assessment of flooding processes in the river basins of world's large rivers, as well as impacts of future climate scenarios. To make the most of such a potential, we believe it is necessary, on the one hand, to understand strengths and limitations of the existing methodologies, and on the other hand, to discuss possibilities and implications of using large scale flood models for operational flood risk assessment and management. Where should researchers put their effort, in order to develop useful and reliable methodologies and outcomes? How the information coming from large scale flood inundation studies can be used by stakeholders? How should we use this information where previous higher resolution studies exist, or where official studies are available?

  6. Lichtheimia Species Exhibit Differences in Virulence Potential

    PubMed Central

    Schwartze, Volker U.; Hoffmann, Kerstin; Nyilasi, Ildikó; Papp, Tamás; Vágvölgyi, 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 37°C 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. On the Potential of Large Ring Lasers

    E-print Network

    G. E. Stedman; R. B. Hurst; K. U. Schreiber

    2007-07-10

    We describe a new ring laser with area A = 833 m^2 and update performance statistics for several such machines. Anandan & Chaio 1982 judged ring lasers inferior to matter interferometers as possible detectors of gravitational waves. However, we note that geophysically interesting results have been obtained from large ring lasers and that there is still a lot of room for improvements.

  8. Calculations in support of a potential definition of large release

    SciTech Connect

    Hanson, A.L.; Davis, R.E.; Mubayi, V.

    1994-05-01

    The Nuclear Regulatory Commission has stated a hierarchy of safety goals with the qualitative safety goals as Level I of the hierarchy, backed up by the quantitative health objectives as Level II and the large release guideline as Level III. The large release guideline has been stated in qualitative terms as a magnitude of release of the core inventory whose frequency should not exceed 10{sup -6} per reactor year. However, the Commission did not provide a quantitative specification of a large release. This report describes various specifications of a large release and focuses, in particular, on an examination of releases which have a potential to lead to one prompt fatality in the mean. The basic information required to set up the calculations was derived from the simplified source terms which were obtained from approximations of the NUREG-1150 source terms. Since the calculation of consequences is affected by a large number of assumptions, a generic site with a (conservatively determined) population density and meteorology was specified. At this site, various emergency responses (including no response) were assumed based on information derived from earlier studies. For each of the emergency response assumptions, a set of calculations were performed with the simplified source terms; these included adjustments to the source terms, such as the timing of the release, the core inventory, and the release fractions of different radionuclides, to arrive at a result of one mean prompt fatality in each case. Each of the source terms, so defined, has the potential to be a candidate for a large release. The calculations show that there are many possible candidate source terms for a large release depending on the characteristics which are felt to be important.

  9. Inversion of potential fields on nodes for large grids

    NASA Astrophysics Data System (ADS)

    Marcotte, Denis; Shamsipour, Pejman; Coutant, Olivier; Chouteau, Michel

    2014-11-01

    The non-iterative direct inversion of potential field data by stochastic approach enables to incorporate in a coherent way a priori geological knowledge, the known densities on any support size and the gravity data. The weakness of the method is the necessary computation of the parameter covariance matrix. For a large mesh made of prisms, the matrix is simply too large to fit in memory. The new approach approximates the prism covariance matrix by a surrogate matrix computed from the covariance matrix of a reduced set of nodes aimed at representing the whole domain of inversion. Care is taken to preserve the properties of direct stochastic inversion on the whole set of prisms. Hence, the approach accounts in a consistent way for the support effect, the inversion remains exact in the absence of noise on data, point and block known densities are exactly reproduced, any set of linear constraints can be applied, and the inversion is non-iterative in all cases. It is shown on synthetic examples that the number of nodes needs not to be very large to ensure a good approximation of the parameter covariance matrix or to ensure similarity of the inversion solutions. An application to a gravity survey including borehole density data shows the applicability of the method for a large number of cells in the inversion domain. Even with as much as 10,000 nodes and one million prisms, the computing time remained acceptable at less than two hours on a workstation. The inverted solution obtained with the nodes approach is compared to a direct kriging of borehole density data and to direct inversion using only the gravity data. The solution combining both information is different from the inversion using only gravity, but only in the area where borehole data are numerous. Although shown for the gravity-density potential, the approach is general and can be extended to magnetic-susceptibility and joint inversion. The proposed approach helps solving the recurrent problem of the application of stochastic inversion to large grids.

  10. Resolvent estimates for perturbations by large magnetic potentials

    SciTech Connect

    Cardoso, Fernando, E-mail: fernando@dmat.ufpe.br; Cuevas, Claudio, E-mail: cch@dmat.ufpe.br [Departamento de Matemática, Universidade Federal de Pernambuco, CEP. 50540-740 Recife-Pe (Brazil)] [Departamento de Matemática, Universidade Federal de Pernambuco, CEP. 50540-740 Recife-Pe (Brazil); Vodev, Georgi, E-mail: vodev@math.univ-nantes.fr [Département de Mathématiques, Université de Nantes, UMR 6629 du CNRS, 2, rue de la Houssinière, BP 92208, 44332 Nantes Cedex 03 (France)] [Département de Mathématiques, Université de Nantes, UMR 6629 du CNRS, 2, rue de la Houssinière, BP 92208, 44332 Nantes Cedex 03 (France)

    2014-02-15

    We prove optimal high-frequency resolvent estimates for self-adjoint operators of the form G = ?? + ib(x) · ? + i? · b(x) + V(x) on L{sup 2}(R{sup n}), n ? 3, where b(x) and V(x) are large magnetic and electric potentials, respectively. No continuity of the magnetic potential is assumed.

  11. Potential for geophysical experiments in large scale tests.

    USGS Publications Warehouse

    Dieterich, J.H.

    1981-01-01

    Potential research applications for large-specimen geophysical experiments include measurements of scale dependence of physical parameters and examination of interactions with heterogeneities, especially flaws such as cracks. In addition, increased specimen size provides opportunities for improved recording resolution and greater control of experimental variables. Large-scale experiments using a special purpose low stress (100MPa).-Author

  12. Lichtheimia Species Exhibit Differences in Virulence Potential

    Microsoft Academic Search

    Volker U. Schwartze; Kerstin Hoffmann; Ildikó Nyilasi; Tamás Papp; Csaba Vágvölgyi; Sybren de Hoog; Kerstin Voigt; Ilse D. Jacobsen

    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

  13. 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 24 kHz and females have the upper limit at 16 kHz. The more sensitive frequency range is 3-15 kHz for males and 1-8 kHz for females. Males have the minimum threshold at 11 kHz (58 dB SPL), higher about 5 dB than that at 3 kHz for females. The best excitatory frequencies of single units are mostly between 3 and 5 kHz in females and at 7-8 kHz in males. The underlying mechanism of auditory sexual differences is discussed. PMID:24510208

  14. Boltzmann Equation with a Large Potential in a Periodic Box

    E-print Network

    Chanwoo Kim

    2011-02-19

    The stability of the Maxwellian of the Boltzmann equation with a large amplitude external potential $\\Phi$ has been an important open problem. In this paper, we resolve this problem with a large $C3-$potential in a periodic box $\\mathbb{T}^d$, $d \\geq 3$. We use [1] in $L^p-L^{\\infty}$ framework to establish the well-posedness and the $L^{\\infty}-$stability of the Maxwellian $\\mu_E(x,v)=\\exp\\{-\\frac{|v|^2}{2}-\\Phi(x)\\}$.

  15. NUMERICAL CALIBRATION OF ELECTRIC POTENTIAL DIFFERENCE FOR CRACK SIZE MONITORING

    Microsoft Academic Search

    R. A. CLÁUDIO; C. M. BRANCO

    The electric potential difference technique is frequently used to monitor crack size propagation in fatigue testing. Crack size is indirectly measured by the change of the electrical field, due to the crack discontinuity, when the component on test is exposed to an electric current flowing through it. The potential difference can be related to crack size through experimental, analytical or

  16. Screaming Cup Large cups of different shapes, sizes and materials

    E-print Network

    Benitez-Nelson, Claudia

    Screaming Cup Materials · Large cups of different shapes, sizes and materials · Nails or other sharp object to puncture cups · Different types of string · Water Process 1. Have each student pick a cup of each size 2. Let each student decorate the cups with permanent markers in Halloween themes (15

  17. Finite difference methods for the solution of unsteady potential flows

    NASA Technical Reports Server (NTRS)

    Caradonna, F. X.

    1982-01-01

    Various problems which are confronted in the development of an unsteady finite difference potential code are reviewed mainly in the context of what is done for a typical small disturbance and full potential method. The issues discussed include choice of equations, linearization and conservation, differencing schemes, and algorithm development. A number of applications, including unsteady three dimensional rotor calculations, are demonstrated.

  18. A micropump based on water potential difference in plants

    Microsoft Academic Search

    Jing Min Li; Chong Liu; Kai Ping Zhang; Xue Ke; Zheng Xu; Chun Yu Li; Li Ding Wang

    In land plants, water vapor diffuses into the air through the stomata. The loss of water vapor creates a water potential difference\\u000a between the leaf and the soil, which draws the water upward. Quantitatively, the water potential difference is 1–2 MPa which\\u000a can support a water column of 100–200 m. Here we present the design and operation of a biomimetic micropump. The

  19. Individual Skill Differences and Large-Scale Environmental Learning

    ERIC Educational Resources Information Center

    Fields, Alexa W.; Shelton, Amy L.

    2006-01-01

    Spatial skills are known to vary widely among normal individuals. This project was designed to address whether these individual differences are differentially related to large-scale environmental learning from route (ground-level) and survey (aerial) perspectives. Participants learned two virtual environments (route and survey) with limited…

  20. 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.

  1. Large Differences in Time Use for Three Data Collection Systems

    Microsoft Academic Search

    Nelly Kalfs; Willem Saris

    1998-01-01

    Two versions of an electronic time use diary are compared with the conventional paper-and-pencil one (or PAPI). One version was a self-administered diary (Computer-Assisted Self-Interview or CASI), while the second was based on an interviewer-administered procedure (Computer-Assisted Telephone Interview or CATI). Comparison of the data collection systems used for time use statistics revealed large differences between the procedures for most

  2. Central ridge of Newfoundland: Little explored, potential large

    SciTech Connect

    Silva, N.R. De (Canada-Newfoundland Offshore Petroleum Board, Newfoundland, St. Johns (Canada))

    1993-10-25

    The Central ridge on the northeastern Grand Banks off Newfoundland represents a large area with known hydrocarbon accumulations and the potential for giant fields. It covers some 17,000 sq km with water less than 400 m deep. The first major hydrocarbon discovery on the Newfoundland Grand Banks is giant Hibernia field in the Jeanne d'Arc basin. Hibernia field, discovered in 1979, has reserves of 666 million bbl and is due onstream in 1997. Since Hibernia, 14 other discoveries have been made on the Grand Banks, with three on the Central ridge. Oil was first discovered on Central Ridge in 1980 with the Mobil et al. South Tempest G-88 well. In 1982 gas was discovered with the Mobil et al. North Dana I-43 well 30 km northeast of the earlier discovery. In 1983 gas and condensate were discovered with the Husky-Bow Valley et al. Trave E-87 well 20 km south of the South Tempest well. These discoveries are held under significant discovery licenses and an additional 2,400 sq km are held under exploration licenses. The paper discusses the history of the basin, the reservoir source traps, and the basin potential.

  3. 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.

  4. 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.

  5. Betavoltaics using scandium tritide and contact potential difference

    Microsoft Academic Search

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

    2008-01-01

    Tritium-powered betavoltaic micropower sources using contact potential difference (CPD) are demonstrated. Thermally stable scandium tritide thin films with a surface activity of 15 mCi?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

  6. Betavoltaics using scandium tritide and contact potential difference

    Microsoft Academic Search

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

    2008-01-01

    Tritium-powered betavoltaic micropower sources using contact potential difference (CPD) are demonstrated. Thermally stable scandium tritide thin films with a surface activity of 15 mCi\\/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

  7. Comparison of different proximity potentials for asymmetric colliding nuclei

    SciTech Connect

    Dutt, Ishwar; Puri, Rajeev K. [Department of Physics, Panjab University, Chandigarh 160014 (India)

    2010-06-15

    Using the different versions of phenomenological proximity potential as well as other parametrizations within the proximity concept, we perform a detailed comparative study of fusion barriers for asymmetric colliding nuclei with asymmetry parameter as high as 0.23. In all, 12 different proximity potentials are robust against the experimental data of 60 reactions. Our detailed study reveals that the surface energy coefficient as well as radius of the colliding nuclei depend significantly on the asymmetry parameter. All models are able to explain the fusion barrier heights within +-10% on the average. The potentials due to Bass 80, AW 95, and Denisov DP explain nicely the fusion cross sections at above- as well as below-barrier energies.

  8. Assessing carbon dynamics in semiarid ecosystems : Balancing potential gains with potential large rapid losses

    SciTech Connect

    Breshears, D. D. (David D.); Ebinger, M. H. (Michael H.); Unkefer, P. J. (Pat J.)

    2001-01-01

    Photosynthesis and respiration are the largest fluxes into and out of the biosphere (Molles 1999). Consequently, small changes in these fluxes can potentially produce large changes in the storage of carbon in the biosphere. Terrestrial carbon fluxes account for more than half of the carbon transferred between the atmosphere and the earth's surface (about 120 GigaTons/year), and current stores of carbon in terrestrial ecosystem are estimated at 2060 GigaTons. Increasing attention is being focused on the role of managing and sequestering carbon in the terrestrial biosphere as a means for addressing global climate change (IGBP, 1998; U.S. Department of Energy, 1999). Terrestrial ecosystems are widely recognized as a major biological scrubber for atmosphereic CO{sub 2} and their ability to finction as such can be increased significantly over the next 25 years through careful manipulation. The potential for terrestrial carbon gains has been the subject of much attention (Dixon et al., 1994; Masera et al. 1997; Cao and Woodward, 1998; DeLucia et al. 1999). In contrast to other strategies for reducing net carbon emissions, terrestrial sequestration has the potential for rapid implementation. Strategies that focus on soil carbon are likely to be effective because in addition to being a storage pool of carbon, soil carbon also improves site productivity through improving soil quality (e.g., water retention and nutrient availability). The carbon pool in soils is immense and highly dynamic. The flux of carbon into and out of soils is one of the largest uncertainties in the total mass balance of global carbon (NRC, 1999; La1 et al., 1998; Cambardella, 1998). Reducing these uncertainties is key to developing carbon sequestration strategies. Soil carbon pools have been greatly depleted over recent centuries, and there is potential to increase storage of carbon in these soils through effective land management. Whereas carbon in vegetation can be managed directly through land use, carbon in soils generally must be managed indirectly through manipulation of vegetation and nutrients. Land management as well as climate changes have the potential to increase soil carbon, but also could trigger large soil carbon losses. Recently, the importance of accounting for countervailing losses in assessing potential amounts of terrestrial carbon that can be sequestered has been highlighted (Schlesinger, 1999; Walker et al., 1999). Realistic assessment of terrestrial carbon sequestration strategies must consider net results of an applied strategy, not simply projected carbon gains. In addition, large, rapid losses of carbon resulting from carbon management strategies could exacerbate the global warming rather than mitigating it. Such potential losses include rapid loss of carbon in vegetation due to fire and rapid loss of soil carbon triggered by reductions in ground cover (e.g., fire, drought). Therefore, strategies for terrestrial carbon sequestration must determine how to increase terrestrial carbon while minimizing the risk of large-scale catastrophic losses. Our objectives in this paper are to (1) highlight approaches that are being considered in terms of terrestrial carbon sequestration, (2) highlight case studies for which large losses of carbon may occur, and (3) suggest future directions and application for terrestrial carbon sequestration.

  9. Peru onshore-deepwater basins should have large potential

    SciTech Connect

    Zuniga-Rivero, F.; Keeling, J.A.; Hay-Roe, H. [BPZ and Associates Inc., Houston, TX (United States)

    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.

  10. 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.

  11. Large cross sections for transitions with a small energy difference

    NASA Astrophysics Data System (ADS)

    McGuire, J. H.; Shakov, Kh. Kh.

    2009-05-01

    Cross sections for transitions between states with small differences in energy can be quite large. An example is the 1s-2p transition in atomic hydrogen caused by the impact of a fast charged particle [1] or a photon [3]. In such cases the actual cross section may become much larger than the simple geometric cross section. Such transitions are often difficult to observe in the laboratory. However, they can be evaluated numerically. This effect can be significant in analysis of astrophysical data, as pointed out by T. Nandi [2]. I discuss a few examples of calculations and give a physical explanation for this effect. [4pt] [1] J.H. McGuire, D. J. Land, J. G. Brennan and G. Basbas, Phys. Rev. A19, 2180 (1979).[0pt] [2] Kh.Kh. Shakov and J.H. McGuire, Phys. Rev. A67 033405 (2003). [0pt] [3] T. Nandi, private communication, 2008.

  12. 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

  13. A Large-Sample Study of Sex Differences in Functional Cerebral Lateralization

    Microsoft Academic Search

    David B. Boles

    2005-01-01

    For practitioners, the importance of sex differences in lateralization lies in their potential prediction of susceptibility to and recovery from hemispheric damage. However, previous literature reviews suggest that sex accounts for only 0.1–1% of the variance in asymmetry scores. Here a large-sample, single-laboratory approach uses tasks requiring the recognition of bargraphs, dichotic words, facial emotions, locations, and visual words, and

  14. Resolving the Difference in Electric Potential within a Charged Macromolecule

    NASA Astrophysics Data System (ADS)

    Luo, Shuangjiang; Yang, Jingfa; Zhao, Jiang

    2013-03-01

    The difference of the electric potential between the middle and end of polystyrene sulfonate (PSS-) chain is discovered experimentally. Using a pH-responsive fluorophore attached to these two locations on the PSS- chain, the local pH value was determined by single molecule fluorescence technique: photon counting histogram (PCH). By the observation of a very high accumulation of proton (2-3 orders of magnitude in concentration) at the vicinity of the PSS- as the result of the electrostatic attraction between the charged chain and protons, the electric potential of the PSS- chain is determined. A higher extent of counterion adsorption is discovered at the middle of the PSS- chain than the chain end. The entropy effect of the counterion adsorption is also discovered - upon the dilution of protons, previously adsorbed counterions are detached from the chain. The difference of the electric potential between the middle and end of polystyrene sulfonate (PSS-) chain is discovered experimentally. Using a pH-responsive fluorophore attached to these two locations on the PSS- chain, the local pH value was determined by single molecule fluorescence technique: photon counting histogram (PCH). By the observation of a very high accumulation of proton (2-3 orders of magnitude in concentration) at the vicinity of the PSS- as the result of the electrostatic attraction between the charged chain and protons, the electric potential of the PSS- chain is determined. A higher extent of counterion adsorption is discovered at the middle of the PSS- chain than the chain end. The entropy effect of the counterion adsorption is also discovered - upon the dilution of protons, previously adsorbed counterions are detached from the chain. Project supported by National Natural Science Foundation of China (NSFC)

  15. Nasal Potential Difference Measurements to Assess CFTR Ion Channel Activity

    PubMed Central

    Clancy, Jean-Paul; Wilschanski, Michael

    2013-01-01

    Nasal potential difference is used to measure the voltage across the nasal epithelium, which results from transepithelial ion transport and reflects in part CFTR function. The electrophysiologic abnormality in cystic fibrosis was first described 30 years ago and correlates with features of the CF phenotype. NPD is an important in vivo research and diagnostic tool, and is used to assess the efficacy of new treatments such as gene therapy and ion transport modulators. This chapter will elaborate on the electrophysiological principles behind the test, the equipment required, the methods, and the analysis of the data. PMID:21594779

  16. Ionization Potentials in the Limit of Large Atomic Number

    NASA Astrophysics Data System (ADS)

    Snyder, John C.

    By extrapolating the energies of non-relativistic atoms and their ions with up to 3000 electrons within Kohn-Sham density functional theory, we find that the ionization potential remains finite and increases across a row, even as Z goes to infinity. The local density approximation for the exchange contribution becomes more accurate (or even exact) in this limit. Extended Thomas-Fermi theory matches the shell-average of both the ionization potential and density change.

  17. Large Scale Predictions of Potential Post-fire Erosion

    Microsoft Academic Search

    M. E. Miller; L. H. MacDonald

    2005-01-01

    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

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

    PubMed

    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

  19. 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 Gonçalves 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

  20. Earth surface potentials measuring device for large grounding systems testing

    Microsoft Academic Search

    R. Giannini; H. Dzapo

    2004-01-01

    Substation grounding system characteristics need to be examined periodically in order to check that protective functions have not been degraded over a longer period of time. The most important safety parameters are the values of touch and step voltages. However, the surface potential distribution contains additional information concerning grounding grid status and possible characteristics degradation trends. Inspection procedure needs to

  1. Large oncocytic adrenocortical tumor with uncertain malignant potential.

    PubMed

    Lee, Chang Ki; Choi, Kyung Hwa; Cha, Yoon Jin; Bum, Jung Ha; Lee, Hyung Ho; Kim, Myung Soo; Park, Won Kyu; Yang, Seung Choul; Han, Woong Kyu

    2011-09-01

    Oncocytoma is a neoplasm consisting of oncocytes that is found in the salivary gland, kidney, and thyroid. Adrenocortical oncocytoma is particularly uncommon, and most cases reported are benign and nonfunctioning. Here, we report a 20 cm adrenal mass associated with necrosis that was identified as an oncocytic adrenocortical tumor with uncertain malignant potential through histopathological evaluation after its resection. PMID:22025964

  2. Large Oncocytic Adrenocortical Tumor with Uncertain Malignant Potential

    PubMed Central

    Lee, Chang Ki; Choi, Kyung Hwa; Cha, Yoon Jin; Bum, Jung Ha; Lee, Hyung Ho; Kim, Myung Soo; Park, Won Kyu; Yang, Seung Choul

    2011-01-01

    Oncocytoma is a neoplasm consisting of oncocytes that is found in the salivary gland, kidney, and thyroid. Adrenocortical oncocytoma is particularly uncommon, and most cases reported are benign and nonfunctioning. Here, we report a 20 cm adrenal mass associated with necrosis that was identified as an oncocytic adrenocortical tumor with uncertain malignant potential through histopathological evaluation after its resection. PMID:22025964

  3. Large divalent cations and electrostatic potentials adjacent to membranes. A theoretical calculation.

    PubMed Central

    Carnie, S; McLaughlin, S

    1983-01-01

    We have extended the Gouy-Chapman theory of the electrostatic diffuse double layer by considering the finite size of divalent cations in the aqueous phase adjacent to a charged surface. The divalent cations are modeled as either two point charges connected by an infinitely thin, rigid "rod" or two noninteracting point charges connected by an infinitely thin, flexible "string." We use the extended theory to predict the effects of a cation of length 10 A (1 nm) on the zeta and surface potentials of phospholipid bilayer membranes. The predictions of the rod and string models are similar to one another but differ markedly from the predictions of the Gouy-Chapman theory. Specifically, the extended model predicts that a large divalent cation will have a smaller effect on the potential adjacent to a negatively charged bilayer membrane than a point divalent cation, that the magnitude of this discrepancy will decrease as the Debye length increases, and that a large divalent cation will produce a negative zeta potential on a membrane formed from zwitterionic lipids. These predictions agree qualitatively with the experimental results obtained with the large divalent cation hexamethonium. We discuss the biological relevance of our calculations in the context of the interaction of cationic drugs with receptor sites on cell membranes. PMID:6661491

  4. Ocular Vestibular Evoked Myogenic Potential Using Different Test Stimuli

    PubMed Central

    Deepak, Dessai Teja; Bhat, Jayashree S.; Kumar, Kaushlendra

    2013-01-01

    Aim. Ocular Evoked Myogenic Potential (oVEMP) are short latency potentials evoked by higher acoustic stimulation. In this study, we aimed at comparing the click, 500?Hz mixed modulated, and 500?Hz short duration tone burst stimuli using oVEMP. Material. Click, 500?Hz mixed modulated and 500?Hz short duration tone burst stimuli were used for the study. Method. Conventional sampling and conveneint study design were used. Sixty healthy subjects underwent contralateral oVEMP testing maintaining 30 degrees upward gaze. Single channel electrode montage was applied to record oVEMP response. Results. On statistical analysis the three stimuli evoked equal response rates (100%), and when latency of n1 and p1 and peak-peak amplitude were compared, the click evoked showed significantly early latency and lower peak-peak amplitude than the 500?Hz stimuli. Five hundred Hz stimuli did not show significant difference in latency and peak-peak amplitude of n1-p1. Discussion. Thus, 500?Hz stimuli can evoke better latency and peak-peak amplitude. oVEMP has good clinical significance in diagnosing subjects with vestibular dysfunction. To add to the sensitivity of the oVEMP test, 500?Hz stimuli may also be used as it can evoke better oVEMP responses in clinical population with good morphology. PMID:23986874

  5. Study of cascades damage in Ni by MD with different interatomic potentials

    NASA Astrophysics Data System (ADS)

    Yao, Z.; Caturla, M. J.; Schäublin, R.

    2007-08-01

    Molecular dynamics (MD) simulations, performed with embedded atom potentials, are used to understand the formation of defects following displacement cascades in Ni. Different empirical potentials, presenting large differences in stacking fault energy (SFE), are used. Simulations were conducted with primary knock-on (PKA) atom energies of 5-40 keV at a temperature of 10 K. Defects include, depending on the potential, individual point defects (vacancies and interstitials), dislocation loops and stacking fault tetrahedra (SFT). The results are related to TEM observations, and the mismatch between these two pictures is discussed. It appears that in a collision cascade, the formation of an SFT does not depend only on the SFE but also on other parameters such as the mobility of vacancies and self-interstitials, or the presence of replacement collision sequences. Based on these calculations we suggest that the formation of clusters of vacancies is a prerequisite to the formation of SFTs.

  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. 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

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

    SciTech Connect

    Fleischmann, H.H.; Zweben, S.J. [Princeton Univ., NJ (United States). Plasma Physics Lab.]|[Cornell Univ., Ithaca, NY (United States). 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.

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

    SciTech Connect

    Fleischmann, H.H.; Zweben, S.J. (Princeton Univ., NJ (United States). Plasma Physics Lab. Cornell Univ., Ithaca, NY (United States). 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.

  10. 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.

  11. 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.

  12. 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.

  13. Gender differences, polypharmacy, and potential pharmacological interactions in the elderly

    PubMed Central

    Venturini, Carina Duarte; Engroff, Paula; Ely, Luísa Scheer; de Araújo Zago, Luísa Faria; Schroeter, Guilherme; Gomes, Irenio; De Carli, Geraldo Attilio; Morrone, Fernanda Bueno

    2011-01-01

    OBJECTIVE: This study aims to analyze pharmacological interactions among drugs taken by elderly patients and their age and gender differences in a population from Porto Alegre, Brazil. METHODS: We retrospectively analyzed the database provided by the Institute of Geriatric and Gerontology, Porto Alegre, Brazil. The database was composed of 438 elderly and includes information about the patients' disease, therapy regimens, utilized drugs. All drugs reported by the elderly patients were classified using the Anatomical Therapeutic and Chemical Classification System. The drug-drug interactions and their severity were assessed using the Micromedex® Healthcare Series. RESULTS: Of the 438 elderly patients in the data base, 376 (85.8%) used pharmacotherapy, 274 were female, and 90.4% of females used drugs. The average number of drugs used by each individual younger than 80 years was 3.2±2.6. Women younger than 80 years old used more drugs than men in the same age group whereas men older than 80 years increased their use of drugs in relation to other age groups. Therefore, 32.6% of men and 49.2% of women described at least one interaction, and 8.1% of men and 10.6% of women described four or more potential drug-drug interactions. Two-thirds of drug-drug interactions were moderate in both genders, and most of them involved angiotensin-converting enzyme inhibitor, non-steroidal anti-inflammatory, loop and thiazide diuretics, and ?-blockers. CONCLUSION: Elderly patients should be closely monitored, based on drug class, gender, age group and nutritional status. PMID:22086515

  14. LARGE-SCALE BIOLOGY ARTICLE The Potential of Text Mining in Data Integration and Network

    E-print Network

    Gent, Universiteit

    LARGE-SCALE BIOLOGY ARTICLE The Potential of Text Mining in Data Integration and Network Biology for Arabidopsis and to uncover gene information through guilt by association. All large- scale data sets, as well., 2012). Recently, in collaboration with the University of Turku, we de- veloped EVEX, a large-scale text

  15. Colorectal carcinomas with microsatellite instability display a different pattern of target gene mutations according to large bowel site of origin

    Microsoft Academic Search

    Manuela Pinheiro; Terje Ahlquist; Stine A Danielsen; Guro E Lind; Isabel Veiga; Carla Pinto; Vera Costa; Luís Afonso; Olga Sousa; Maria Fragoso; Lúcio Santos; Rui Henrique; Paula Lopes; Carlos Lopes; Ragnhild A Lothe; Manuel R Teixeira

    2010-01-01

    BACKGROUND: Only a few studies have addressed the molecular pathways specifically involved in carcinogenesis of the distal colon and rectum. We aimed to identify potential differences among genetic alterations in distal colon and rectal carcinomas as compared to cancers arising elsewhere in the large bowel. METHODS: Constitutional and tumor DNA from a test series of 37 patients with rectal and

  16. 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

  17. Differences in the Glucuronidation of Resveratrol and Pterostilbene: Altered Enzyme Specificity and Potential Gender Differences

    PubMed Central

    Dellinger, Ryan W.; Gomez Garcia, Angela M.; Meyskens, Frank L.

    2015-01-01

    Summary Resveratrol, a natural polyphenol found in grapes, berries and other plants, has been proposed as an ideal chemopreventative agent due to its plethora of health promoting activities. However, despite its lofty promise as a cancer prevention agent its success in human clinical trials has been limited due to its poor bioavailability. Thus, interest in other natural polyphenols is intensifying including the naturally occurring dimethylated analog of resveratrol, pterostilbene. The UDP-glucuronosyltransferase (UGT) family of enzymes plays a vital role in the metabolism of both resveratrol and pterostilbene. The current study sought to elucidate the UGT family members responsible for the metabolism of pterostilbene and to examine gender differences in the glucuronidation of resveratrol and pterostilbene. We demonstrate that UGT1A1 and UGT1A3 are mainly responsible for pterostilbene glucuronidation although UGT1A8, UGT1A9 and UGT1A10 also had detectable activity. Intriguingly, UGT1A1 exhibits the highest activity against both resveratrol and pterostilbene despite altered hydroxyl group specificity. Using pooled human liver microsomes, enzyme kinetics were determined for pterostilbene and resveratrol glucuronides. In all cases females were more efficient than males, indicating potential gender differences in stilbene metabolism. Importantly, the glucuronidation of pterostilbene is much less efficient than that of resveratrol, indicating that pterostilbene will have dramatically decreased metabolism in humans. PMID:23965644

  18. Chemopreventive Potential of Sorghum with Different Phenolic Profiles 

    E-print Network

    Yang, Liyi

    2010-07-14

    significant QR inducing potential; on the other hand, non-tannin sorghums increased QR activity by 1.5-2.7 times; black sorghum (Tx430) was most potent (doubled QR activity at 25 mg/mL, 2.7-fold increase at 100 mg/mL). All sorghum extracts showed relatively...

  19. Obtaining Potential Field Solutions with Spherical Harmonics and Finite Differences

    Microsoft Academic Search

    Gábor Tóth; Bart van der Holst; Zhenguang Huang

    2011-01-01

    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,

  20. Estimation of wind energy potential using different probability density functions

    Microsoft Academic Search

    Tian Pau Chang

    2011-01-01

    In addition to the probability density function (pdf) derived with maximum entropy principle (MEP), several kinds of mixture probability functions have already been applied to estimate wind energy potential in scientific literature, such as the bimodal Weibull function (WW) and truncated Normal Weibull function (NW). In this paper, two other mixture functions are proposed for the first time to wind

  1. Axial current reversal promotes synchronous correlation between dendritic membrane potentials during large scale synaptic input.

    E-print Network

    Halliday, David

    is a time domain transfer function analysis between the membrane potential fluctuations at different sites and timing of individual synaptic inputs combine to produce the fluctuations of the membrane potential, these membrane potential fluctuations will ultimately act to modulate the timing of output spikes (Calvin

  2. Effect of large ion angular momentum spread and high current on inertial electrostatic confinement potential structures

    SciTech Connect

    Tzonev, I.V.; DeMora, J.M.; Miley, G.H. [Univ. of Illinois, Urbana, IL (United States)

    1995-12-31

    Prior Inertial Electrostatic Confinement (IEC) studies have assumed that very low angular momentum (zero in the ideal case) is necessary to achieve a potential well structure capable of trapping energetic ions in the center of a spherical device. However, the present study shows that high-current ion beams having large-angular-momentum spread can also form deep potential well traps.

  3. Effect of large ion angular momentum spread and high current on inertial electrostatic confinement potential structures

    Microsoft Academic Search

    Ivon V. Tzonev; John M. DeMora; George H. Miley

    1995-01-01

    Prior inertial electrostatic confinement (IEC) studies have assumed that very low angular momentum (zero in the ideal case) is necessary to achieve a potential well structure capable of trapping energetic ions in the center of a spherical device. However, the present study shows that high-current ion beams having large-angular-momentum spread can also form deep potential well traps

  4. The multiparameter control of carbon potential in large scale continuous dripping carburization furnace

    SciTech Connect

    Liang, X.M.; Wang, Z. [Heat Treatment Plant of FAW, Chang Chun (China); Zhang, H. [Chang Chun Automotive Material Research Inst. (China)

    1995-12-31

    By the investigation of the effects on the carbon potential in a Large scale continuous dripping carburization furnace, this paper presents a new thought in which air was used as the control agent in the control of carbon potential. An advanced mathematical model of process control and a multiparameter control system were established. The system has been used in production and performed very well.

  5. Behavior of the chemical potential of neutral atoms in the limit of large nuclear charge

    Microsoft Academic Search

    José Luis Gázquez; Alberto Vela; Marcelo Galván

    1986-01-01

    It is shown that in the limit of large nuclear charge Z, the chemical potential of a neutral atom is given by mu~Z-1\\/3X periodic function of Z1\\/3. This expression accounts for the general behavior of the chemical potential of atoms in the Periodic Table.

  6. 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 ?-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 ?-glucosidase activity assay was the most responsive of them. PMID:21767865

  7. Whitefly control potential of Eretmocerus parasitoids with different reproductive modes

    Microsoft Academic Search

    M. J. Ardeh

    2005-01-01

    Whiteflies (Homoptera; Aleyrodidae) are amongst the key pests of vegetable, ornamental, and agronomic crops throughout the world. Because of failing and expensive chemical control, much research has been directed at developing biological control by searching for efficient natural enemies of whiteflies. Among different categories of natural enemies, parasitoids have been efficient control agents and cost effective. The aim of the

  8. Systematic study of the fusion barriers using different proximity-type potentials for N=Z colliding nuclei: New extensions

    SciTech Connect

    Dutt, Ishwar; Puri, Rajeev K. [Department of Physics, Panjab University, Chandigarh 160 014 (India)

    2010-04-15

    By using 14 different versions and parametrizations of a proximity potential and two new versions of the potential proposed in this paper, we perform a comparative study of fusion barriers by studying 26 symmetric reactions. The mass asymmetry eta{sub A}=((A{sub 2}-A{sub 1}/A{sub 2}+A{sub 1})), however, is very large. Our detailed investigation reveals that most of the proximity potentials reproduce experimental data within +-8% on average. A comparison of fusion cross sections indicates that Bass 80, AW 95, and Denisov DP potentials have a better edge than other potentials. We also propose new versions of the proximity potential as well as Denisov parametrized potential. These new versions improve agreement with the data.

  9. Global Solutions of Shock Reflection by Large-Angle Wedges for Potential Flow

    E-print Network

    Gui-Qiang Chen; Mikhail Feldman

    2007-08-19

    When a plane shock hits a wedge head on, it experiences a reflection-diffraction process 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 shock reflection may occur, including regular and Mach reflection. However, most of the fundamental issues for shock reflection have not been understood, including the global structure, stability, and transition of the different patterns of shock reflection. Therefore, it is essential to establish the global existence and structural stability of solutions of shock reflection in order to understand fully the phenomena of shock reflection. On the other hand, there has been no rigorous mathematical result on the global existence and structural stability of shock reflection, including the case of potential flow which is widely used in aerodynamics. Such problems involve several challenging difficulties in the analysis of nonlinear partial differential equations such as mixed equations of elliptic-hyperbolic type, free boundary problems, and corner singularity where an elliptic degenerate curve meets a free boundary. In this paper we develop a rigorous mathematical approach to overcome these difficulties involved and establish a global theory of existence and stability for shock reflection by large-angle wedges for potential flow. The techniques and ideas developed here will be useful for other nonlinear problems involving similar difficulties.

  10. 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.

  11. 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

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

    NASA Astrophysics Data System (ADS)

    Iturrate, I.; Chavarriaga, R.; Montesano, L.; Minguez, J.; Millán, 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.

  13. 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.

  14. Vermicomposting potential of Perionyx sansibaricus (Perrier) in different waste materials.

    PubMed

    Suthar, Surendra

    2007-04-01

    The decomposition efficiency of Perionyx sansibaricus (Perrier) for vermicomposting was evaluated by using a variety of wastes such as agriculture waste, farm yard manure and urban solid waste. Vermicomposting resulted in significant increase in total N (80.8-142.3%), phosphorous (33.1-114.6%) and potassium (26.3-125.2%), whereas decrease in organic C (14.0-37.0%) as well as C:N ratio (52.4-69.8%) in different experimental beddings. P. sansibaricus showed maximum biomass production, growth rate (mg day(-1)), mean cocoon numbers, and reproduction rate (cocoon worm(-1)) in VLL (vegetable waste+leaf litter) as compared to other substrate materials. There was a consistent trend for earthworms' growth and reproduction rate, related to initial N-content of the substrate (P<0.05), but there was no clear effect of C:N ratio of the composted material on earthworm cocoon numbers and weight gain. Earthworm showed minimum total population mortality in VLL and maximum in HHCD (household waste+cow dung), after 150 days of experimentation. The increased level of plant metabolites in end product (vermicompost) and growth patterns of P. sansibaricus in different organic waste resources demonstrated the candidature of this species for wastes recycle operations at low-input basis. PMID:16828549

  15. Transepithelial potential difference of a single gill filament isolated from the crayfish Astacus leptodactylus Esch.: a new method.

    PubMed

    Barradas, C; Dunel-Erb, S; Lignon, J

    1997-02-01

    A new method is described that allows in vitro perfusion and transepithelial electrical potential measurements of a single filament (3-5 mm long; 200 microns in diameter) isolated from the podobranch of the crayfish Astacus leptodactylus. An electrophysiological study was carried out on the preparation to validate this technique. The good physiological quality of the isolated filament preparation has been established and results of continuous measurements of the potential difference under two perfusion conditions are reported. Filaments were perfused with Van Harreveld physiological saline inside and either with Van Harreveld saline or artificial fresh water outside. Large potential differences up to 150 mV between inside and outside of the filament were recorded. When filaments were symmetrically perfused, the behavior of the electrical potential difference allowed two populations of filaments to be distinguished. PMID:9224545

  16. Anomalously Large Difference in Dipole Moment of Isomers with Nearly Identical Thermodynamic Stability

    E-print Network

    Yu, Fangqun

    Anomalously Large Difference in Dipole Moment of Isomers with Nearly Identical Thermodynamic to form stable aqueous hydrogen- bonded clusters/complexes. The electrical dipole moment of such clusters and drastically different dipole moments. The difference in the dipole moment of mono-, di-, and trihydrates

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

    Microsoft Academic Search

    Harshi Weerasinghe; Uwe A. Schneider

    2010-01-01

    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

  18. Identifying potential environmental impacts of large-scale deployment of dedicated bioenergy crops in the UK

    Microsoft Academic Search

    Rebecca L. Rowe; Gail Taylor

    2009-01-01

    There is momentum, globally, to increase the use of plant biomass for the production of heat, power and liquid transport fuels. This review assesses the evidence base for potential impacts of large-scale bioenergy crop deployment principally within the UK context, but with wider implications for Europe, the USA and elsewhere. We focus on second generation, dedicated lignocellulosic crops, but where

  19. Potential energy surface and large amplitude motions of the water-carbon dioxide complex

    Microsoft Academic Search

    J. Makarewicz; Tae-Kyu Ha; A. Bauder

    1993-01-01

    The results of abinitio investigations of the equilibrium structure and the potential energy surface of water–carbon dioxide are presented. It has been found that the complex has two equivalent, slightly nonplanar equilibrium configurations. A hydrogen-bonded structure has not been found. Large amplitude van der Waals motions of the complex have been studied and the vibrational and rotational energy levels have

  20. Large Evoked Potentials to Dynamic Random-Dot Correlograms and Stereograms Permit Quick Determination of Stereopsis

    Microsoft Academic Search

    B. Julesz; W. Kropfl; B. Petrig

    1980-01-01

    The combination of three technological innovations permits the fast and objective determination of stereopsis in nonverbal subjects: (i) It is shown that dynamic random-dot correlograms (RDC) are as effective as dynamic random-dot stereograms (RDS) in eliciting large evoked potentials (EP), and that the generation of RDC is simpler than that of RDS. (ii) The presentation of RDC in the form

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

    Microsoft Academic Search

    Chien Wang; Ronald G. Prinn

    2011-01-01

    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

  2. Heavy quark potential at finite temperature in a dual gravity closer to large N QCD

    NASA Astrophysics Data System (ADS)

    Patra, Binoy Krishna; Khanchandani, Himanshu

    2015-03-01

    In gauge-gravity duality, heavy quark potential at finite temperature is usually calculated with the pure AdS background, which does not capture the renormalisation group (RG) running in the gauge theory part and the potential also does not contain any confining term in the deconfined phase. Following the developments on the Klebanov-Strassler geometry, we employ a geometry which captures the RG flow similar to QCD, to obtain the heavy quark potential by analytically continuing the string configurations into the complex plane. In addition to the attractive terms, the obtained potential has confining terms both at T = 0 and T ? 0 , compared to the calculations usually done in the literature, where only Coulomb like term is present in the deconfined phase. The potential also develops an (negative) imaginary part above a critical separation, rc (=0.53 zh) . Moreover our potential exhibits a behaviour, different from the usual Debye screening obtained from the perturbation theory.

  3. Precipitating electron fluxes formed by a magnetic field aligned potential difference

    Microsoft Academic Search

    David S. Evans

    1974-01-01

    A model is developed in which a magnetic field aligned potential difference is assumed to accelerate electrons downward into the atmosphere. It is pointed out that the upgoing backscattered electrons produced by this electron beam may process insufficient kinetic energy to overcome the hypothetical potential difference. These electrons will be reflected downward to appear as members of a precipitating electron

  4. 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

  5. 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.

  6. Potential and attainable food production and food security in different regions

    PubMed Central

    Vries, F. W. T. Penning de; Rabbinge, R.; Groot, J. J. R.

    1997-01-01

    Growing prosperity in the South is accompanied by human diets that will claim more natural resources per capita. This reality, combined with growing populations, may raise the global demand for food crops two- to four-fold within two generations. Considering the large volume of natural resources and potential crop yields, it seems that this demand can be met smoothly. However, this is a fallacy for the following reasons. (i) Geographic regions differ widely in their potential food security: policy choices for agricultural use of natural resources are limited in Asia. For example, to ensure national self-sufficiency and food security, most of the suitable land (China) and nearly all of the surface water (India) are needed. Degradation restricts options further. (ii) The attainable level of agricultural production depends also on socio-economic conditions. Extensive poverty keeps the attainable food production too low to achieve food security, even when the yield gap is wide, as in Africa. (iii) Bio-energy, non-food crops and nature compete with food crops for natural resources. Global and regional food security are attainable, but only with major efforts. Strategies to achieve alternative aims will be discussed.

  7. 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

  8. Compact Finite Difference Time Domain Absorbing Boundary Conditions for Electrically Large Waveguide Modeling

    Microsoft Academic Search

    Mohammed F. Hadi

    2009-01-01

    This work extends a previous effort in optimizing the compact finite difference time domain algorithm for modeling electrically large waveguides by investigating the effect of their electrical size on perfectly matched layer absorbing boundary conditions. Sensitivity analysis is conducted via an optimization procedure where actual finite difference time domain simulations serve as input, and optimum perfectly matched layer parameters serve

  9. Modeling the large-scale water balance impact of different irrigation systems

    E-print Network

    Evans, Jason

    Modeling the large-scale water balance impact of different irrigation systems J. P. Evans1 and B. F. [1] In this study, two parameterizations for different irrigation techniques have been implemented­atmosphere interactions associated with traditional flood irrigation--a widespread but highly water-inefficient practice

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

    Microsoft Academic Search

    Jacob Grunwald; Dino Marcus; Yoel Papier; Lily Raveh; Zipora Pittel; Yacov Ashani

    1997-01-01

    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

  11. How to know and choose online games: differences between current and potential players.

    PubMed

    Teng, Ching-I; Lo, Shao-Kang; Wang, Pe-Cheng

    2007-12-01

    This study investigated how different adolescent players acquire game information and the criteria they use in choosing online games and found that (1) current players generally use comprehensive information sources more than potential players do; (2) current players rely on free trials and smooth display of motion graphics as choice criteria more than potential players do; (3) potential players rely on the look of advertisements more than current players do; (4) both current and potential players most likely use word-of-mouth and gaming programs on TV as information sources; and (5) endorser attractiveness is ranked the least important among six choice criteria by both current and potential players. PMID:18085974

  12. 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 opportunities through 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

  13. Investigating the Potential for Large-Scale Carbon Dioxide Sequestration in Shale Gas Formations

    NASA Astrophysics Data System (ADS)

    Edwards, R.; Celia, M. A.; Kanno, C.; Bandilla, K.; Doster, F.

    2014-12-01

    Recent studies [Godec et al., Int. J. Coal. Geol., 2013; Liu et al., IJGGC, 2013; Tao and Clarens, ES&T, 2013] have suggested the possibility of geological CO2 sequestration in depleted shale gas formations, motivated by large storage capacity estimates in these formations. The kinetics and practicality of injecting large amounts of CO2 into shale gas wells at the appropriate scale remain as open questions. To further investigate the feasibility of CO2 sequestration, models of gas flow and storage in a horizontal shale gas well were developed based on observed behavior of gas production data and the associated models that are consistent with those observations [Patzek et al., PNAS, 2013]. Both analytical and numerical models were used to investigate the well-scale kinetics of CO2 injection into a typical shale gas well. It was found that relatively low rates could be injected into individual wells compared with CO2 emissions from large industrial sources, and that injection rates would rapidly decline with time. Based on typical well parameters, 170 wells would be required to inject the emissions from one large coal-fired power plant over a 15 year period. Significant practical and logistical challenges to industrial-scale CO2 sequestration in depleted shale gas formations arise due to the relatively low injection rates, low storage capacity of individual wells and large numbers of wells required. These challenges include the difficulty of managing the required large, ever-changing networks of injection wells, potentially prohibitive energy requirements, and leakage concerns in hydraulically fractured wells. The combination of these factors, and the fact that they are all likely less of an issue for other potential geological sequestration targets such as deep saline aquifers, mean that targets in conventional formations are more likely to be suitable for industrial-scale CO2 sequestration.

  14. Relationship between Visual Evoked Potentials and Subjective Differences between Emotional Expressions in “Face Diagrams”

    Microsoft Academic Search

    Ch. A. Izmailov; S. G. Korshunova; E. N. Sokolov

    2001-01-01

    The relationship between visual evoked potentials resulting from substitution of one image of a human “face diagram” for another and assessment of perceived differences between the emotional expressions of these faces were studied. Emotions were altered by changing the curvature of the mouth and\\/or the slope of the brows. Unlike the traditional approach, in which visual evoked potentials are recorded

  15. Research article Potential and realized reproduction by different worker castes in queen-less

    E-print Network

    Suarez, Andrew V.

    ). Trophic egg-laying requires a developed and functional reproductive system in workers. Thus, in speciesResearch article Potential and realized reproduction by different worker castes in queen when colonies are orphaned. In this study, we assessed the reproductive potential of workers of each

  16. 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.

  17. Dendritic cells derived from pluripotent stem cells: Potential of large scale production

    PubMed Central

    Li, Yan; Liu, Meimei; Yang, Shang-Tian

    2014-01-01

    Human pluripotent stem cells (hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, are promising sources for hematopoietic cells due to their unlimited growth capacity and the pluripotency. Dendritic cells (DCs), the unique immune cells in the hematopoietic system, can be loaded with tumor specific antigen and used as vaccine for cancer immunotherapy. While autologous DCs from peripheral blood are limited in cell number, hPSC-derived DCs provide a novel alternative cell source which has the potential for large scale production. This review summarizes recent advances in differentiating hPSCs to DCs through the intermediate stage of hematopoietic stem cells. Step-wise growth factor induction has been used to derive DCs from hPSCs either in suspension culture of embryoid bodies (EBs) or in co-culture with stromal cells. To fulfill the clinical potential of the DCs derived from hPSCs, the bioprocess needs to be scaled up to produce a large number of cells economically under tight quality control. This requires the development of novel bioreactor systems combining guided EB-based differentiation with engineered culture environment. Hence, recent progress in using bioreactors for hPSC lineage-specific differentiation is reviewed. In particular, the potential scale up strategies for the multistage DC differentiation and the effect of shear stress on hPSC differentiation in bioreactors are discussed in detail. PMID:24567783

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

    Microsoft Academic Search

    Ou Lydia Liu; Mark Wilson

    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 (e.g., multiple-choice items, open constructed-response items). The U.S. portion of the

  19. Accurate measurement of large optical frequency differences with a mode-locked laser

    Microsoft Academic Search

    J. Reichert; R. Holzwarth; T. W. Hänsch

    1999-01-01

    We have used the comb of optical frequencies emitted by a mode-locked laser as a ruler to measure differences of as much as 20 THz between laser frequencies. This is to our knowledge the largest gap measured with a frequency comb, with high potential for further improvements. To check the accuracy of this approach we show that the modes are

  20. Analytical solitary-wave solutions of the generalized nonautonomous cubic-quintic nonlinear Schroedinger equation with different external potentials

    SciTech Connect

    He Junrong; Li Huamei [Department of Physics, Zhejiang Normal University, Jinhua, Zhejiang 321004 (China)

    2011-06-15

    A large family of analytical solitary wave solutions to the generalized nonautonomous cubic-quintic nonlinear Schroedinger equation with time- and space-dependent distributed coefficients and external potentials are obtained by using a similarity transformation technique. We use the cubic nonlinearity as an independent parameter function, where a simple procedure is established to obtain different classes of potentials and solutions. The solutions exist under certain conditions and impose constraints on the coefficients depicting dispersion, cubic and quintic nonlinearities, and gain (or loss). We investigate the space-quadratic potential, optical lattice potential, flying bird potential, and potential barrier (well). Some interesting periodic solitary wave solutions corresponding to these potentials are then studied. Also, properties of a few solutions and physical applications of interest to the field are discussed. Finally, the stability of the solitary wave solutions under slight disturbance of the constraint conditions and initial perturbation of white noise is discussed numerically; the results reveal that the solitary waves can propagate in a stable way under slight disturbance of the constraint conditions and the initial perturbation of white noise.

  1. Potential and Attainable Food Production and Food Security in Different Regions

    Microsoft Academic Search

    R. Rabbinge; J. J. R. Groot

    1997-01-01

    Growing prosperity in the South is accompanied by human diets that will claim more natural resources per capita. This reality, combined with growing populations, may raise the global demand for food crops two-to four-fold within two generations. Considering the large volume of natural resources and potential crop yields, it seems that this demand can be met smoothly. However, this is

  2. Potential and attainable food production and food security in different regions

    Microsoft Academic Search

    R. Rabbinge; J. J. R. Groot

    1997-01-01

    Growing prosperity in the South is accompanied by human diets that will claim more natural resources per capita. This reality, combined with growing populations, may raise the global demand for food crops two- to four-fold within two generations. Considering the large volume of natural resources and potential crop yields, it seems that this demand can be met smoothly. However, this

  3. 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…

  4. 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…

  5. Student Engagement at a Large Suburban Community College: Gender and Race Differences

    ERIC Educational Resources Information Center

    Sontam, Varalakshmi; Gabriel, George

    2012-01-01

    Previous research shows that there are individual differences in academic achievement associated with gender and race. Research also suggests that student engagement is an important determinant of student outcomes/achievement. The present study explored student engagement at an extra-large community college. It specifically investigated possible…

  6. Angular dependent potential for ?-boron and large-scale molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Pokatashkin, P.; Kuksin, A.; Yanilkin, A.

    2015-06-01

    Both quantum mechanical and molecular-dynamics (MD) simulations of ?-boron are done at this work. Angular dependent interatomic potential (ADP) for boron is obtained using force-matching technique. Fitting data are based on ab initio results within???20..100 GPa pressure range and temperatures up to 2000 K. Characteristics of ?-boron, obtained using ADP potential such as bond lengths at equilibrium condition, bulk modulus, pressure-volume relations, Gruneisen coefficient, thermal expansion coefficient are in good agreement with both ab initio data, obtained in this work and known experimental data. As an example of application, the propagation of shock waves through a single crystal of ?-boron is also explored by large-scale MD simulations.

  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 liposome’s size, compared to the liposome’s 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. Differences in seed rain composition in small and large fragments in the northeast Brazilian Atlantic Forest.

    PubMed

    Knörr, U C; Gottsberger, G

    2012-02-28

    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

  9. Large N Spectrum of two Matrices in a Harmonic Potential and BMN energies

    E-print Network

    Joao P. Rodrigues

    2005-10-28

    The large N spectrum of the quantum mechanical hamiltonian of two hermitean matrices in a harmonic potential is studied in a framework where one of the matrices is treated exactly and the other is treated as a creation operator impurity in the background of the first matrix. For the free case, the complete set of invariant eigenstates and corresponding energies are obtained. When g_{YM}^2 interactions are added, it is shown that the full string tension corrected spectrum of BMN loops is obtained.

  10. Exploring the potential energy landscape over a large parameter-space

    NASA Astrophysics Data System (ADS)

    He, Yang-Hui; Mehta, Dhagash; Niemerg, Matthew; Rummel, Markus; Valeanu, Alexandru

    2013-07-01

    Solving large polynomial systems with coefficient parameters are ubiquitous and constitute an important class of problems. We demonstrate the computational power of two methods — a symbolic one called the Comprehensive Gröbner basis and a numerical one called coefficient-parameter polynomial continuation — applied to studying both potential energy landscapes and a variety of questions arising from geometry and phenomenology. Particular attention is paid to an example in flux compactification where important physical quantities such as the gravitino and moduli masses and the string coupling can be efficiently extracted.

  11. Temporal-spatial changes in Sonic Hedgehog expression and signaling reveal different potentials of ventral

    E-print Network

    Paris-Sud XI, Université de

    Temporal-spatial changes in Sonic Hedgehog expression and signaling reveal different potentials ARTICLE Open Access Temporal-spatial changes in Sonic Hedgehog expression and signaling reveal different mesencephalic precursors that express Sonic Hedgehog (Shh). However, Shh expression, which is initially confined

  12. 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…

  13. 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.

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

    PubMed Central

    Redjadj, Claire; Darmon, Gaëlle; Maillard, Daniel; Chevrier, Thierry; Bastianelli, Denis; Verheyden, Hélène; Loison, Anne; Saïd, 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

  15. Intra- and interspecific differences in diet quality and composition in a large herbivore community.

    PubMed

    Redjadj, Claire; Darmon, Gaëlle; Maillard, Daniel; Chevrier, Thierry; Bastianelli, Denis; Verheyden, Hélène; Loison, Anne; Saïd, 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. Gender Differences in Sexual Attitudes and Behaviors: A Review of Meta-Analytic Results and Large Datasets

    Microsoft Academic Search

    Jennifer L. Petersen; Janet Shibley Hyde

    2011-01-01

    Gender differences in sexual attitudes and behaviors are typically believed to be large, yet recent evidence suggests that some gender differences in sexuality are much smaller than common knowledge would suggest. This article reviews gender differences in sexual attitudes and behaviors as reported by major meta-analyses and large datasets. In particular, this article reviews gender differences in heterosexual intercourse, masturbation,

  17. Generation and detection of large and robust entanglement between two different mechanical resonators in cavity optomechanics

    E-print Network

    Li, J; Malossi, N; Zippilli, S; Vitali, D

    2015-01-01

    We investigate a general scheme for generating, either dynamically or in the steady state, continuous variable entanglement between two mechanical resonators with different frequencies. We employ an optomechanical system in which a single optical cavity mode driven by a suitably chosen two-tone field is coupled to the two resonators. Significantly large mechanical entanglement can be achieved, which is extremely robust with respect to temperature.

  18. Soil carbon dioxide efflux determined from large undisturbed soil cores collected in different soil management systems

    Microsoft Academic Search

    Eszter Tóth; Sándor Koós; Csilla Farkas

    2009-01-01

    The aim of this study was to evaluate a measuring technique for determining soil CO2 efflux from large soil samples having undisturbed structure under controlled laboratory conditions. Further objectives were\\u000a to use the developed measuring method for comparing soil CO2 efflux from samples, collected in three different soil management systems at various soil water content values. The experimental\\u000a technique was

  19. Commercial processed food may have endocrine-disrupting potential: soy-based ingredients making the difference.

    PubMed

    Omoruyi, Iyekhoetin Matthew; Kabiersch, Grit; Pohjanvirta, Raimo

    2013-01-01

    Processed and packaged food items as well as ready-to-eat snacks are neglected and poorly characterised sources of human exposure to endocrine-disrupting chemicals (EDCs). In this study we investigated the presence of xenoestrogens in commercially processed and packaged Finnish foods, arising from substances deliberately added or inadvertently contaminating the food, substances formed as a result of food processing, or substances leaching from food packaging materials. Samples were obtained in three separate batches of equivalent products from both a supermarket and a local representative of a global chain of hamburger restaurants and extracted by a solid-phase extraction method. Their endocrine-disrupting potential was determined by yeast bioluminescent assay, using two recombinant yeast strains Saccharomyces cerevisiae BMAEREluc/ER? and S. cerevisiae BMA64/luc. In this test system, the majority of samples (both foodstuffs and wrappers) analysed proved negative. However, all batches of industrially prepared hamburgers (but not those obtained from a hamburger restaurant) as well as pepper salami significantly induced luciferase activity in the BMAEREluc/ER? yeast strain indicating the presence of xenoestrogens, with estradiol equivalents of these products ranging from 0.2 to 443 pg g(-1). All three products contained soy-based ingredients, which apparently accounted for, or at least contributed to, their high estrogenic activity, since no signal in the assay was observed with extracts of the packaging material, while two different soy sauces tested yielded an intense signal (28 and 54 pg ml(-1) estradiol-equivalent). These findings imply that by and large chemicals arising in the processing or packaging of foodstuffs in Finland constitute an insignificant source of xenoestrogens to consumers. However, soy-derived ingredients in certain food items might render the entire products highly estrogenic. The estrogenic activity of soy is attributed to isoflavones whose health effects - though widely considered beneficial - are controversial. As hamburgers are a popular type of food among children, the findings are noteworthy and possibly of concern. PMID:23886479

  20. Epigenetic Signatures Associated with Different Levels of Differentiation Potential in Human Stem Cells

    Microsoft Academic Search

    Pablo Aranda; Xabier Agirre; Esteban Ballestar; Enrique J. Andreu; José Román-Gómez; Inés Prieto; José Ignacio Martín-Subero; Juan Cruz Cigudosa; Reiner Siebert; Manel Esteller; Felipe Prosper

    2009-01-01

    BackgroundThe therapeutic use of multipotent stem cells depends on their differentiation potential, which has been shown to be variable for different populations. These differences are likely to be the result of key changes in their epigenetic profiles.Methodology\\/Principal Findingsto address this issue, we have investigated the levels of epigenetic regulation in well characterized populations of pluripotent embryonic stem cells (ESC) and

  1. 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.

  2. Metabolic efficiency of Geobacter sulfurreducens growing on anodes with different redox potentials.

    PubMed

    Bosch, Julian; Lee, Keun-Young; Hong, Siang-Fu; Harnisch, Falk; Schröder, Uwe; Meckenstock, Rainer U

    2014-06-01

    Microorganisms respiring Fe(III) in the environment face a range of redox potentials of the prospective terminal ferric electron acceptors, because Fe(III) can be present in different minerals or organic complexes. We investigated the adaptation of Geobacter sulfurreducens to this range by exposing the bacteria to different redox potentials between the electron donor acetate and solid, extracellular anodes in a microbial fuel-cell set-up. Over a range of anode potentials from -0.105 to +0.645 V versus standard hydrogen electrode, G. sulfurreducens produced identical amounts of biomass per electron respired. This indicated that the organism cannot utilize higher available energies for energy conservation to ATP, and confirmed recent studies. Either the high potentials cannot be used due to physiological limitations, or G. sulfurreducens decreased its metabolic efficiency, and less biomass per unit of energy was produced. In this case, G. sulfurreducens "wasted" energy at high-potential differences, most likely as heat to fuel growth kinetics. PMID:24554342

  3. 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.

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

    SciTech Connect

    Massimi, Paola; Thomas, Miranda [International Centre for Genetic Engineering and Biotechnology, Padriciano 99, I-34012 Trieste (Italy); Bouvard, Veronique [Infections and Cancer Biology Group, International Agency for Research on Cancer - World Health Organization, 150 Cours Albert Thomas, 69372 Lyon (France); Ruberto, Irene [International Centre for Genetic Engineering and Biotechnology, Padriciano 99, I-34012 Trieste (Italy); Campo, M. Saveria [Division of Pathological Sciences, Institute of Comparative Medicine, University of Glasgow, Garscube Estate, Glasgow G61 1QH (United Kingdom); Tommasino, Massimo [Infections and Cancer Biology Group, International Agency for Research on Cancer - World Health Organization, 150 Cours Albert Thomas, 69372 Lyon (France); Banks, Lawrence [International Centre for Genetic Engineering and Biotechnology, Padriciano 99, I-34012 Trieste (Italy)], E-mail: banks@icgeb.org

    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.

  5. AN APPLICATION OF THE DIFFERENCE POTENTIALS METHOD TO SOLVING EXTERNAL PROBLEMS IN CFD

    E-print Network

    Tsynkov, Semyon V.

    AN APPLICATION OF THE DIFFERENCE POTENTIALS METHOD TO SOLVING EXTERNAL PROBLEMS IN CFD Victor S by the numerous computational experiments and espe- cially concerns the area of CFD, in which external problems present a wide class of practically impor- tant formulations. In this paper, we review some work that has

  6. Active Cl ? absorption by the Chinese crab ( Eriocheir sinensis ) gill epithelium measured by transepithelial potential difference

    Microsoft Academic Search

    Horst Onken; Kai Graszynski

    1989-01-01

    Isolated posterior gills from Chinese crabs (Eriocheir sinensis) acclimated to tap-water were perfused and bathed with full, physiological saline (containing Na+ and Cl-). Under these conditions they developed an outside positive transepithelial potential difference (PDte). Substitution of Na+ by choline on both sides of the epithelium resulted in a substantial hyperpolarization of the PDte, while substitution of Cl- by gluconate

  7. Different Arbuscular Mycorrhizal Fungal Species Are Potential Determinants of Plant Community Structure

    Microsoft Academic Search

    Thomas Boller; Andres Wiemken; Ian R. Sanders

    1998-01-01

    Almost all natural plant communities contain arbuscular mycorrhizal fungi (AMF). We hypothesized that the species composition of AMF communities could have the potential to determine plant community structure if the growth response to different AMF species or to communities of AMF species varies among plant species. To test the existence of such a differential response we conducted a pot experiment

  8. College Grade Point Average as a Personnel Selection Device: Ethnic Group Differences and Potential Adverse Impact

    Microsoft Academic Search

    Philip L. Roth; Philip Bobko

    2000-01-01

    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

  9. Sex differences in face gender recognition: An event-related potential study

    Microsoft Academic Search

    Yueting Sun; Xiaochao Gao; Shihui Han

    2010-01-01

    Multiple level neurocognitive processes are involved in face processing in humans. The present study examined whether the early face processing such as structural encoding is modulated by task demands that manipulate attention to perceptual or social features of faces and such an effect, if any, is different between men and women. Event-related brain potentials were recorded from male and female

  10. 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...

  11. 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…

  12. Rooting of stem cuttings of Populus x euramericana under different water potentials

    E-print Network

    Paris-Sud XI, Université de

    water losses coupled with either low water absorption or slow water transport through the conductingRooting of stem cuttings of Populus x euramericana under different water potentials S. Puri1 F is affected by many environmental factors (Haissig, 1974; Puri and Shamet, 1988). The main- tenance of water

  13. Impact of Potential Large-Scale Irrigation on the West African Monsoon and Its Dependence on Location of Irrigated Area

    E-print Network

    Im, Eun-Soon

    This study investigates the impact of potential large-scale irrigation on the West African monsoon using the Massachusetts Institute of Technology regional climate model (MRCM). A new irrigation module is implemented to ...

  14. 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.

  15. Multiple mechanisms involved in the large-spectrum therapeutic potential of cannabidiol in psychiatric disorders.

    PubMed

    Campos, Alline Cristina; Moreira, Fabricio Araújo; Gomes, Felipe Villela; Del Bel, Elaine Aparecida; Guimarães, Francisco Silveira

    2012-12-01

    Cannabidiol (CBD) is a major phytocannabinoid present in the Cannabis sativa plant. It lacks the psychotomimetic and other psychotropic effects that the main plant compound ?(9)-tetrahydrocannabinol (THC) being able, on the contrary, to antagonize these effects. This property, together with its safety profile, was an initial stimulus for the investigation of CBD pharmacological properties. It is now clear that CBD has therapeutic potential over a wide range of non-psychiatric and psychiatric disorders such as anxiety, depression and psychosis. Although the pharmacological effects of CBD in different biological systems have been extensively investigated by in vitro studies, the mechanisms responsible for its therapeutic potential are still not clear. Here, we review recent in vivo studies indicating that these mechanisms are not unitary but rather depend on the behavioural response being measured. Acute anxiolytic and antidepressant-like effects seem to rely mainly on facilitation of 5-HT1A-mediated neurotransmission in key brain areas related to defensive responses, including the dorsal periaqueductal grey, bed nucleus of the stria terminalis and medial prefrontal cortex. Other effects, such as anti-compulsive, increased extinction and impaired reconsolidation of aversive memories, and facilitation of adult hippocampal neurogenesis could depend on potentiation of anandamide-mediated neurotransmission. Finally, activation of TRPV1 channels may help us to explain the antipsychotic effect and the bell-shaped dose-response curves commonly observed with CBD. Considering its safety profile and wide range of therapeutic potential, however, further studies are needed to investigate the involvement of other possible mechanisms (e.g. inhibition of adenosine uptake, inverse agonism at CB2 receptor, CB1 receptor antagonism, GPR55 antagonism, PPAR? receptors agonism, intracellular (Ca(2+)) increase, etc.), on CBD behavioural effects. PMID:23108553

  16. Artificial neural networks approach for zeta potential of Montmorillonite in the presence of different cations

    NASA Astrophysics Data System (ADS)

    Yukselen, Yeliz; Erzin, Yusuf

    2008-05-01

    In this study, the zeta potential of montmorillonite in the presence of different chemical solutions was modeled by means of artificial neural networks (ANNs). Zeta potential of the montmorillonite was measured in the presence of salt cations, Na+, Li+ and Ca2+ and metals Zn2+, Pb2+, Cu2+, and Al3+ at different pH values, and observed values pointed to a different behavior for this mineral in the presence of salt and heavy metal cations. Artificial neural networks were successfully developed for the prediction of the zeta potential of montmorillonite in the presence of salt and heavy metal cations at different pH values and ionic strengths. Resulting zeta potential of montmorillonite shows different behavior in the presence of salt and heavy metal cations, and two ANN models were developed in order to be compared with experimental results. The ANNs results were found to be close to experimentally measured zeta potential values. The performance indices such as coefficient of determination, root mean square error, mean absolute error, and variance account for were used to control the performance of the prediction capacity of the models developed in this study. These indices obtained make it clear that the predictive models constructed are quite powerful. The constructed ANN models exhibited a high performance according to the performance indices. This performance has also shown that the ANNs seem to be a useful tool to minimize the uncertainties encountered during the soil engineering projects. For this reason, the use of ANNs may provide new approaches and methodologies.

  17. 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

  18. Analysis of the Potential for a Heat Island Effect in Large Solar Vasilis Fthenakis1,2

    E-print Network

    widespread installation of solar panels and found this to be small compared to benefits from the reductionAnalysis of the Potential for a Heat Island Effect in Large Solar Farms Vasilis Fthenakis1 Abstract -- Large-scale solar power plants are being built at a rapid rate, and are setting up to use

  19. Bounds on potential risks and causal risk differences under assumptions about confounding parameters.

    PubMed

    Chiba, Yasutaka; Sato, Tosiya; Greenland, Sander

    2007-12-10

    Nonparametric bounds on causal effects in observational studies are available under deterministic potential-outcome models. We derive narrower bounds by adding assumptions regarding bias due to confounding. This bias is defined as the difference between the expectation of potential outcomes for the exposed group and that for the unexposed group. We show that crude effect measures bound causal effects under the given assumptions. We then derive bounds for randomized studies with noncompliance, which are given by the per protocol effect. With perfect compliance in one treatment group, the direction of effect becomes identifiable under our assumptions. Although the assumptions are not themselves identifiable, they are nonetheless reasonable in some situations. PMID:17525935

  20. Large-scale psychological differences within China explained by rice versus wheat agriculture.

    PubMed

    Talhelm, T; Zhang, X; Oishi, S; Shimin, C; Duan, D; Lan, X; Kitayama, S

    2014-05-01

    Cross-cultural psychologists have mostly contrasted East Asia with the West. However, this study shows that there are major psychological differences within China. We propose that a history of farming rice makes cultures more interdependent, whereas farming wheat makes cultures more independent, and these agricultural legacies continue to affect people in the modern world. We tested 1162 Han Chinese participants in six sites and found that rice-growing southern China is more interdependent and holistic-thinking than the wheat-growing north. To control for confounds like climate, we tested people from neighboring counties along the rice-wheat border and found differences that were just as large. We also find that modernization and pathogen prevalence theories do not fit the data. PMID:24812395

  1. Large eddy simulation of zero-pressure-gradient turbulent boundary layer based on different scaling laws

    NASA Astrophysics Data System (ADS)

    Cheng, Wan; Samtaney, Ravi

    2013-11-01

    We present results of large eddy simulation (LES) for a smooth-wall, zero-pressure-gradient turbulent boundary layer. We employ the stretched vortex sub-grid-scale model in the simulations augmented by a wall model. Our wall model is based on the virtual-wall model introduced by Chung & Pullin (J. Fluid Mech 2009). An essential component of their wall model is an ODE governing the local wall-normal velocity gradient obtained using inner-scaling ansatz. We test two variants of the wall model based on different similarity laws: one is based on a log-law and the other on a power-law. The specific form of the power law scaling utilized is that proposed by George & Castillo (Appl. Mech. Rev. 1997), dubbed the ``GC Law''. Turbulent inflow conditions are generated by a recycling method, and applying scaling laws corresponding to the two variants of the wall model, and a uniform way to determine the inlet friction velocity. For Reynolds number based on momentum thickness, Re? , ranging from 104 to 1012 it is found that the velocity profiles generally follow the log law form rather than the power law. For large Reynolds number asymptotic behavior, LES based on different scaling laws the boundary layer thickness and turbulent intensities do not show much difference. We present results of large eddy simulation (LES) for a smooth-wall, zero-pressure-gradient turbulent boundary layer. We employ the stretched vortex sub-grid-scale model in the simulations augmented by a wall model. Our wall model is based on the virtual-wall model introduced by Chung & Pullin (J. Fluid Mech 2009). An essential component of their wall model is an ODE governing the local wall-normal velocity gradient obtained using inner-scaling ansatz. We test two variants of the wall model based on different similarity laws: one is based on a log-law and the other on a power-law. The specific form of the power law scaling utilized is that proposed by George & Castillo (Appl. Mech. Rev. 1997), dubbed the ``GC Law''. Turbulent inflow conditions are generated by a recycling method, and applying scaling laws corresponding to the two variants of the wall model, and a uniform way to determine the inlet friction velocity. For Reynolds number based on momentum thickness, Re? , ranging from 104 to 1012 it is found that the velocity profiles generally follow the log law form rather than the power law. For large Reynolds number asymptotic behavior, LES based on different scaling laws the boundary layer thickness and turbulent intensities do not show much difference. Supported by a KAUST funded project on large eddy simulation of turbulent flows. The IBM Blue Gene P Shaheen at KAUST was utilized for the simulations.

  2. Rainbows in rotationally inelastic scattering: a comparative study of different model potential surfaces and dynamical approximations

    SciTech Connect

    Schinke, R.; Korsch, H.J.; Poppe, D.

    1982-12-15

    Rainbow structures in rotationally elastic and inelastic differential cross sections in atom--diatom collisions are investigated by comparison of three model potential energy surfaces labeled I, II, and III which are represented by V(R,..gamma..) = V/sub 0/(R)+V/sub 2/(R)P/sub 2/(cos ..gamma..). The cross sections are calculated within the quantal infinite-order-sudden (IOS) approximation. The anisotropic part V/sub 2/ is the same for all potentials and purely repulsive. The isotropic part V/sub 0/ for potential I is also repulsive and the differential cross sections show the well-studied rotational rainbow structures. Structural changes occur for collisions in potential II and III which have V/sub 0/ terms being attractive at intermediate and large atom--molecule separations and having well depths of 10% and 25% of the collision energy, respectively. For example, the elastic cross section has no classical rainbow in the case of potential I but three in the case of potential III. The rainbow structures are analyzed within the classical and semiclassical versions of the IOS approximation and interpreted in terms of catastrophe theory. The quantitative comparison of the classical with the quantal IOS cross sections manifests possible quantum effects, i.e., tunneling into nonclassical regions and interference effects due to the superposition of several contributions (up to six in the present study). They can be very prominent and thus we conclude that much caution is needed if experimental data are compared with classical calculations. The accuracy of the IOS approximation is tested by comparison of classical IOS cross sections with cross sections obtained from exact classical trajectory calculations. The agreement is generally good with the exemption of the rainbow region and small angle, rotationally elastic scattering.

  3. Potentials and constraints of different types of soil moisture observations for flood simulations in headwater catchments

    Microsoft Academic Search

    Axel Bronstert; Benjamin Creutzfeldt; Thomas Graeff; Irena Hajnsek; Maik Heistermann; Sibylle Itzerott; Thomas Jagdhuber; David Kneis; Erika Lück; Dominik Reusser; Erwin Zehe

    Flood generation in mountainous headwater catchments is governed by rainfall intensities, by the spatial distribution of rainfall\\u000a and by the state of the catchment prior to the rainfall, e.g. by the spatial pattern of the soil moisture, groundwater conditions\\u000a and possibly snow. The work presented here explores the limits and potentials of measuring soil moisture with different methods\\u000a and in

  4. Differences between discontinuous and continuous soft-core attractive potentials: The appearance of density anomaly

    Microsoft Academic Search

    Giancarlo Franzese; Departament de Fisica Fonamental; Facultat de Fisica

    2007-01-01

    Soft-core attractive potentials can give rise to a phase diagram with three fluid phases at different densities (gas, low-density liquid and high-density liquid), separated by first order phase transition lines ending in critical points. Experiments show a phase diagram with these features for phosphorous and triphenyl phosphite. Liquid–liquid phase transition could be relevant for water, silica, liquid metals, colloids and

  5. 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.

  6. 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

  7. 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

  8. Frequency Spectrum of Transepithelial Potential Difference Reveals Transport-Related Oscillations

    PubMed Central

    Montalbetti, Nicolás; Fischbarg, Jorge

    2009-01-01

    How epithelia transport fluid is a fundamental issue that is unresolved. Explanations offered include molecular engines, local transcellular osmosis, local paracellular osmosis, and paracellular fluid transport. On the basis of experimental and theoretical work done on corneal endothelium, a fluid transporting epithelium, we suggest electroosmotic coupling at the level of the intercellular junctions driven by the transendothelial electrical potential difference as an explanation of paracellular fluid transport. We collect frequency spectra of that potential difference in real-time. For what we believe is the first time for any epithelium, we report that, unexpectedly, the potential difference displays oscillations at many characteristic frequencies. We also show that on both stimulating cell activity and inhibiting ion transport mechanisms, there are corresponding changes in the oscillations amplitudes that mirror changes known previously in rates of fluid transport. We believe these findings provide a novel tool to study the kinetics of electrogenic elements such as channels and transporters, which from this evidence would give rise to current oscillations with characteristic periods going from 150 ms to 8 s. PMID:19751657

  9. 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.

  10. 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.

  11. Analysis of the Normal Stress Differences of Viscoelastic Fluids under Large Amplitude Oscillatory Shear Flow

    NASA Astrophysics Data System (ADS)

    Nam, Jung Gun; Hyun, Kyu; Ahn, Kyung Hyun; Lee, Seung Jong

    2008-07-01

    The dynamic response of viscoelastic fluids under large amplitude oscillatory shear (LAOS) has been a subject of long history. In the LAOS flow, the analysis has been mostly focused on shear stress, possibly due to the lack of accurate measurement of normal stresses. However, as the instrumentation advances, it becomes possible to get more reliable data. The development of normal stresses under LAOS flow is a significant nonlinear effect that has been hardly obtainable in previous studies. Analyzing the normal stresses will be helpful in understanding and characterizing nonlinear viscoelastic behavior. In this work, we investigated the behavior of normal stress difference under LAOS flow using viscoelastic fluids including Boger fluid and polyethylene oxide aqueous solution. The first normal stress difference was measured and it was sinusoidal at a frequency twice that of the excitation frequency because of its dependence only on the magnitude of the strain, not on the direction of its operation. It showed a displacement that was equal to the elastic modulus multiplied by the square of the strain amplitude. It was also found that the shape of the first normal stress difference strongly depended on shear strain and frequency. At higher frequency, they showed asymmetric patterns in contrast to the shear stress, and the first normal stress difference became larger in magnitude than the shear stress. And higher harmonics of the first normal stress difference which are the sum of even functions were compared with that of shear stress in terms of Fourier spectra, which was also performed with the help of constitutive equations.

  12. On the factors behind large Labrador Sea tides during the last glacial cycle and the potential implications for Heinrich events

    NASA Astrophysics Data System (ADS)

    Arbic, Brian K.; Mitrovica, Jerry X.; Macayeal, Douglas R.; Milne, Glenn A.

    2008-09-01

    Labrador Sea (LS) tidal elevations over the last glacial cycle are investigated in a near-global numerical model that accurately captures the present-day tides. From ˜65 ka to ˜7 ka, the modeled elevations at the debouchement point of the Hudson Strait ice stream in the LS are exceptionally large, comparable to the largest elevations seen anywhere in the present-day ocean. New numerical simulations performed for this article demonstrate that both local changes in basin geometry (e.g., ice cover over Hudson Bay) and changes outside of the LS led to enhanced LS paleotides. New simulations run at higher horizontal resolution and a considered examination of uncertainties, including uncertainties in the adopted sea level models, strengthen confidence in the robustness of the large LS paleotides. The tide model is run with both spatially uniform sea level drops (taken from curves of eustatic and Red Sea sea levels versus time) and spatially variable sea level maps (taken from two different gravitationally self-consistent viscoelastic solid earth/sea level models, which both account for ice sheet geometry). The tides are larger when the spatially variable sea level models are used. Observations in present-day Antarctica indicate that the mechanical action of tides significantly impacts the dynamics of both continental ice streams and their associated floating ice shelves. It is postulated here that large LS paleotides played a key role in the formation of Heinrich event icebergs, that is, massive discharges of ice from the LS into the glacial North Atlantic ocean. The paleotide calculations described here provide a potential explanation for why the LS region, more than any other, dominated the production of Heinrich event icebergs. Most previous hypotheses of a tidal role in climate variability and ice sheet dynamics focus on tidal mixing. In contrast, here the role of tidal mechanical forcing of ice sheets is emphasized.

  13. 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.

  14. 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.

  15. Large differences in catch per unit of effort between two minnow trap models

    PubMed Central

    2013-01-01

    Background Little is known about variation in catch per unit of effort (CPUE) in stickleback fisheries, or the factors explaining this variation. We investigated how nine-spined stickleback (Pungitius pungitius) CPUE was influenced by trap model by comparing the CPUEs of two very similar minnow trap models fished side-by-side in a paired experimental design. Results The galvanized trap type (mean CPUE?=?1.31 fish h–1) out-fished the black trap type (mean CPUE?=?0.20 fish h–1) consistently, and yielded on average 81% more fish. Conclusions The results demonstrate that small differences in trap appearance can have large impacts on CPUE. This has implications for studies designed to investigate abundance and occurrence of fish using minnow traps. PMID:23590839

  16. Large-scale plasma transport in the magnetotail during different solar wind conditions

    NASA Astrophysics Data System (ADS)

    Myllys, Minna; Kilpua, Emilia; Pulkkinen, Tuija

    2015-04-01

    We present results from a study on how solar wind conditions affect the energy and plasma transport in the geomagnetic tail and how they modify the large-scale magnetotail configuration. We study the large-scale plasma transport in the magnetotail using tail observations from the five THEMIS spacecrafts during 2008-2011. During this period the THEMIS spacecraft spent a considerable time in the geomagnetic tail allowing us to compile statistical maps of plasma flow and energy transport properties. Furthermore, this time period corresponds to the extended and prolonged solar activity minimum between solar cycle 23 and 24 and relatively quiet rising phase of cycle 24. This allowed us to investigate magnetospheric processes and solar wind-magnetospheric coupling during relatively quiet state of the magnetosphere. In order to separate the role of different solar wind parameters and their activity level on the average sunward and tailward plasma flows and the occurrence rate of fast plasma bursts, the magnetospheric data was binned according to solar wind speed, dynamic pressure and IMF measurements. Our results show that the tailward flow bursts are not dependent on the solar wind conditions, but that the sign of the IMF z-component (GSM coordinates) causes the most visible effect to the occurence rate and pattern of sunward flows.

  17. Direct measurement of potential difference across the human red blood cell membrane.

    PubMed

    Jay, A W; Burton, A C

    1969-02-01

    The electrical potential difference across the human red cell membrane has been measured directly. A biological amplifier with neutralized input capacity was used. Human red cells in modified Ringer solution were impaled individually with 3 M KCl-filled glass microelectrodes. Movements of the microelectrodes were effected by Leitz micromanipulators. Results showed a potential difference of -8.0 +/- 0.21 (SEM) mv, the inside being negative with respect to the outside. This value is approximately that calculated by using the Nernst equation considering the intracellular and extracellular chloride concentrations.As a control, similar measurements were made on nylon microcapsules containing hemoglobin. The measured potential of -0.52 +/- 0.02 (SEM) mv, which agreed very well with the value calculated on the basis of Donnan equilibrium, was much smaller in magnitude as compared to the results for the red cell, and there was evidence of fixed charges on the microcapsule membrane. There was no evidence of this in the case of the red cell. PMID:5764221

  18. Potential nitrification and denitrification on different surfaces in a constructed treatment wetland.

    PubMed

    Kallner Bastviken, Sofia; Eriksson, Peder G; Martins, Irene; Neto, João M; Leonardson, Lars; Tonderski, Karin

    2003-01-01

    Improved understanding of the importance of different surfaces in supporting attached nitrifying and denitrifying bacteria is essential if we are to optimize the N removal capacity of treatment wetlands. The aim of this study was therefore to examine the nitrifying and denitrifying capacity of different surfaces in a constructed treatment wetland and to assess the relative importance of these surfaces for overall N removal in the wetland. Intact sediment cores, old pine and spruce twigs, shoots of Eurasian watermilfoil (Myriophyllum spicatum L.), and filamentous macro-algae were collected in July and November 1999 in two basins of the wetland system. One of the basins had been constructed on land that contained lots of wood debris, particularly twigs of coniferous trees. Potential nitrification was measured using the isotope-dilution technique, and potential denitrification was determined using the acetylene-inhibition technique in laboratory microcosm incubations. Nitrification rates were highest on the twigs. These rates were three and 100 times higher than in the sediment and on Eurasian watermilfoil, respectively. Potential denitrification rates were highest in the sediment. These rates were three times higher than on the twigs and 40 times higher than on Eurasian watermilfoil. The distribution of denitrifying bacteria was most likely due to the availability of organic material, with higher denitrification rates in the sediment than on surfaces in the water column. Our results indicate that denitrification, and particularly nitrification, in treatment wetlands could be significantly increased by addition of surfaces such as twigs. PMID:14674568

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

    PubMed Central

    Michaelis, Martin; Agha, Bishr; Rothweiler, Florian; Löschmann, 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

  20. Mountain birch - potentially large source of sesquiterpenes into high latitude atmosphere

    NASA Astrophysics Data System (ADS)

    Haapanala, S.; Ekberg, A.; Hakola, H.; Tarvainen, V.; Rinne, J.; Hellén, H.; Arneth, A.

    2009-11-01

    Emissions of volatile organic compounds (VOCs) from mountain birches were measured in Abisko, northern Sweden. Mountain birches make up the majority of the tree biomass in Scandinavian high latitudes, a region subject to significant climate warming. The measurements were carried out in two growing seasons. The emissions of four branches, each from a different individual tree, were measured in June-August 2006 and one of them again in July 2007. The measurements were conducted using a dynamic flow through chamber covered with Teflon film. The studied mountain birches were found to emit substantial amounts of linalool, monoterpenes and sesquiterpenes. The monoterpene emission was dominated by sabinene. The magnitude and composition of the sesquiterpene emission changed dramatically between the years. For example, the average ?-farnesene emission potential in 2006 was almost 2600 ng gdw-1 h-1 (3.5 pmol gdw-1 s-1) while in 2007 ?-farnesene was not detected at all. Also the emissions of other sesquiterpenes decreased in 2007 to a fraction of that in 2006. One possible explanation for the change in emissions is the herbivory damage that occurred in the area in 2004. Herbivory is known to enhance the emissions of sesquiterpenes, especially those of ?-farnesene, and the effect may last for several years.

  1. Differences in Allergenic Potential of Food Extracts following Oral Exposure in Mice Reflect Differences in Digestibility: Potential Approaches to Safety Assessment

    Microsoft Academic Search

    Christal C. Bowman; MaryJane K. Selgrade

    2008-01-01

    An animal model for food allergy is needed to assess genetically modified food crops for potential allergenicity. The ideal model must produce allergic antibody (IgE) to proteins differentially according to known allergenicity before being used to accurately identify potential allergens among novel proteins. The oral route is the most relevant for exposure to food antigens, and a protein's stability to

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

    PubMed

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

    PubMed

    Paíno, T; Paiva, B; Sayagués, J M; Mota, I; Carvalheiro, T; Corchete, L A; Aires-Mejía, I; Pérez, J J; Sanchez, M L; Barcena, P; Ocio, E M; San-Segundo, L; Sarasquete, M E; García-Sanz, R; Vidriales, M-B; Oriol, A; Hernández, M-T; Echeveste, M-A; Paiva, A; Blade, J; Lahuerta, J-J; Orfao, A; Mateos, M-V; Gutiérrez, 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

  4. Large-Time Asymptotics of Solutions to the Kramers-Fokker-Planck Equation with a Short-Range Potential

    NASA Astrophysics Data System (ADS)

    Wang, Xue Ping

    2015-06-01

    In this work, we use a scattering method to study the Kramers-Fokker-Planck equation with a potential whose gradient tends to zero at the infinity. For short-range potentials in dimension three, we show that complex eigenvalues do not accumulate at low-energies and obtain the low-energy resolvent asymptotics. This, combined with high energy pseudospectral estimates valid in more general situations, gives the large-time asymptotics of solutions in weighted L 2 spaces.

  5. Potential for large-scale submarine slope failure and tsunami generation along the US mid-Atalantic coast

    NSDL National Science Digital Library

    Driscoll, Neal W.

    2000-01-01

    This paper from the journal GEOLOGY, "Potential for large-scale submarine slope failure and tsunami generation along the US mid-Atlantic coast," by Neal W. Driscoll, Jeffrey K. Weissel, and John A. Goff, has made headlines in recent weeks for its claim that the outer continental shelf off the coasts of Virginia and North Carolina "might be in the initial stages of large-scale slope failure." Such failure would likely produce a significant Tsunami effect along the eastern coast.

  6. Local contact potential difference of molecular self-assemblies investigated by Kelvin probe force microscopy

    NASA Astrophysics Data System (ADS)

    Spadafora, Evan J.; Linares, Mathieu; Nisa Yahya, Wan Zaireen; Lincker, Frédéric; Demadrille, Renaud; Grevin, Benjamin

    2011-12-01

    Self-assembled pi-conjugated oligomer nanowires have been investigated by frequency modulation atomic force microscopy and amplitude modulation Kelvin probe force microscopy under ultra high vacuum. The distance dependence of the contact potential difference (CPD) has been analyzed by combining high resolution imaging with distance-spectroscopy measurements. It is shown that the apparition of a damping contrast characterizes the onset of short range electrostatic (SRE) forces, which are responsible for the occurrence of local CPD (LCPD) modulations correlated with the molecular lattice. By working at the onset of the damping contrast, the tip-surface separation can be adjusted to minimize the contribution of SRE forces to the measured CPD.

  7. 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

  8. Structure of different within-plate magmatic system of large igneous provinces

    NASA Astrophysics Data System (ADS)

    Sharkov, E.

    2009-04-01

    It is generally accepted that formation of continental large igneous provinces (LIPs) is linked with ascending of mantle superplumes. However, it is not clear yet why and how magmatic systems appeared and functionated. It is known that LIPs are formed by numerous magmatic centers, which imply existence of individual magmatic systems beneath them. Such a situation can be explained by presence of protuberances (local plumes) on the surface of extended superplume heads, where processes of adiabatic melting occurred give rise to formation of magmatic systems. Newly-formed melts on their way to the surface pass through complicate system of conduits and transitional magma chambers, where they were undergone by different processes of crystallizing differentiation, mixing, assimilation of wall-rocks, etc. According to data available, three major levels of transitional magmatic chambers, linked by systems of feeder conduits (dikes), occurred within the crust. Each of them is responsible for transformation of a primary melt in different extent: The lowest level with the largest chambers, located along boundary between upper margin of the plume head and incumbent rigid lithosphere; they are responsible for the underplating phenomenon. Processes of contamination mantle-derived magmas by crustal material can play essential role here, especially in the late Archean and early Paleoproterozoic when they led to appearance of specific mantle-crustal magmas of siliceous high-Mg series (SHMS), which formed large igneous provinces with numerous mafic-iltramafic layered intrusions (Sharkov, Bogina, 2006). It suggests that formation of this series was linked with "floating up" of chambers (batches) of high-temperature ultramafic magmas through the upper part of lithospheric mantle and mafic lower crust by zone refinement mechanism, i.e. by melting material of the chamber's roof and crystallization at their bottoms. As a result, the primary melt gradually enriched in crustal material; portions of such series of melts periodically arrived into hardening transitional magma chambers of the middle level. Very likely that such structure of magmatic systems was typical also for the earliest Moon's magnesian suite magmatism, where such type layered mafic-ultramafic intrusions was found (Snyder et al., 1995). (2) Processes at the middle level are easy to understand on example of large layered mafic-ultramafic intrusions which are represent hardened transition magma chambers. Crystallizing differentiation as well as mixing of periodically arrived into hardening intrusive chambers fresh portions of magmas with evolved melts in it occurred here. Specific type of transitional magma chambers are represented by huge bimodal anorthosite-rapakivi granite complexes (ARGCs), typical for the Mesoproterozoic. They were formed under conditions of unusually thick (70-80 km at the moment) continental crust. Geological, geochemical and isotope data evidence that melting in the mantle and silicic crust occurred here simultaneously above local mantle plumes. It suggests that melting of the crust's material occurred above sill-like intrusions of basaltic melt which were led to appearance of large magma chambers, where mafic and sialic melts coexisted; such chambers represented now as ARGCs. By contrast to continental crust, under conditions of thin oceanic crust processes at the low and middle levels of magmatic systems are united, and layered mafic-ultramafic intrusions occurred directly between the ultramafic mantle and rocks of the upper crust, play role of the lower oceanic crust, how it is easily to observe on example of ophiolite associations. (3) The shallow level - subvolcanic chambers (usually sills), from which melts arrive to the surface, forming individual volcanoes and lava plateaus. Processes of contamination of wall rocks and crystallizing differentiation are very limited here due to small size of bodies and, accordingly, low heat keeping and quickly hardening. So, primary magmatic melt can reach the surface very rare; as a rule, it had undergone

  9. Heavy Quark Potential at Finite Temperature in a Dual Gravity Closer to Large N QCD

    E-print Network

    Binoy Krishna Patra; Himanshu Khanchandani

    2015-04-01

    In gauge-gravity duality, the heavy quark potential at finite temperature is usually calculated with the pure AdS background, which does not capture the renormalization group (RG) running in the gauge theory part. In addition, the potential does not contain any confining term in the deconfined phase. Following the Klebanov-Strassler geometry, we employ a geometry, which captures the RG flow similar to QCD, to obtain the heavy quark potential by analytically continuing the string configurations into the complex plane. In addition to the attractive terms, the obtained potential has confining terms both at $T = 0$ and $T \

  10. 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.

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

    SciTech Connect

    Uehara, Takeki, E-mail: takeki.uehara@shionogi.co.jp [Drug Developmental Research Laboratories, Shionogi and Co., Ltd., 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825 (Japan); Toxicogenomics Informatics Project, National Institute of Biomedical Innovation, 7-6-8 Asagi, Ibaraki, Osaka 567-0085 (Japan); Minowa, Yohsuke; Morikawa, Yuji [Toxicogenomics Informatics Project, National Institute of Biomedical Innovation, 7-6-8 Asagi, Ibaraki, Osaka 567-0085 (Japan); Kondo, Chiaki; Maruyama, Toshiyuki; Kato, Ikuo [Drug Developmental Research Laboratories, Shionogi and Co., Ltd., 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825 (Japan); Nakatsu, Noriyuki; Igarashi, Yoshinobu; Ono, Atsushi [Toxicogenomics Informatics Project, National Institute of Biomedical Innovation, 7-6-8 Asagi, Ibaraki, Osaka 567-0085 (Japan); Hayashi, Hitomi [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Harumi-cho, Fuchu, Tokyo 183-8509 (Japan); Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193 Gifu (Japan); Mitsumori, Kunitoshi [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Harumi-cho, Fuchu, Tokyo 183-8509 (Japan); Yamada, Hiroshi [Toxicogenomics Informatics Project, National Institute of Biomedical Innovation, 7-6-8 Asagi, Ibaraki, Osaka 567-0085 (Japan); Ohno, Yasuo [National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan); Urushidani, Tetsuro [Toxicogenomics Informatics Project, National Institute of Biomedical Innovation, 7-6-8 Asagi, Ibaraki, Osaka 567-0085 (Japan); Department of Pathophysiology, Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kodo, Kyotanabe, Kyoto 610-0395 (Japan)

    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.

  12. 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.

  13. Serial changes in nasal potential difference and lung electrical impedance tomography at high altitude.

    PubMed

    Mason, Nicholas P; Petersen, Merete; Melot, Christian; Imanow, Bakyt; Matveykine, Olga; Gautier, Marie-Therese; Sarybaev, Akpay; Aldashev, Almaz; Mirrakhimov, Mirsaid M; Brown, Brian H; Leathard, Andrew D; Naeije, Robert

    2003-05-01

    Recent work suggests that treatment with inhaled beta(2)-agonists reduces the incidence of high-altitude pulmonary edema in susceptible subjects by increasing respiratory epithelial sodium transport. We estimated respiratory epithelial ion transport by transepithelial nasal potential difference (NPD) measurements in 20 normal male subjects before, during, and after a stay at 3,800 m. NPD hyperpolarized on ascent to 3,800 m (P < 0.05), but the change in potential difference with superperfusion of amiloride or isoprenaline was unaffected. Vital capacity (VC) fell on ascent to 3,800 m (P < 0.05), as did the normalized change in electrical impedance (NCI) measured over the right lung parenchyma (P < 0.05) suggestive of an increase in extravascular lung water. Echo-Doppler-estimated pulmonary artery pressure increases were insufficient to cause clinical pulmonary edema. There was a positive correlation between VC and NCI (R(2) = 0.633) and between NPD and both VC and NCI (R(2) = 0.267 and 0.418). These changes suggest that altered respiratory epithelial ion transport might play a role in the development of subclinical pulmonary edema at high altitude in normal subjects. PMID:12471048

  14. Large Vestibular Evoked Myogenic Potentials in Response to Bone-Conducted Sounds in Patients with Superior Canal Dehiscence Syndrome

    Microsoft Academic Search

    Krister Brantberg; Lennart Löfqvist; Per-Anders Fransson

    2004-01-01

    Dehiscence of the superior semicircular canal is a ‘new’ vestibular entity. Among these patients, the vestibular evoked myogenic potentials (VEMP) in response to air-conducted sounds are large. In the present study, VEMP in response to bone-conducted sounds were studied in 5 normal subjects, in 3 patients after (unilateral) labyrinthectomy and in 4 patients with (unilateral) superior canal dehiscence syndrome. The

  15. The transport sectors potential contribution to the flexibility in the power sector required by large-scale wind power integration

    Microsoft Academic Search

    Per Nørgaard; H. Lund; B. V. Mathiesen

    In 2006, the Danish Society of Engineers developed a visionary plan for the Danish energy system in 2030. The paper presents and qualifies selected part of the analyses, illustrating the transport sectors potential to contribute to the flexibility in the power sector, necessary for large-scale integration of renewable energy in the power system - in specific wind power. In the

  16. Oncogenic NRAS, KRAS, and HRAS Exhibit Different Leukemogenic Potentials in Mice

    PubMed Central

    Parikh, Chaitali; Subrahmanyam, Ramesh; Ren, Ruibao

    2008-01-01

    RAS proteins are small GTPases that play a central role in transducing signals that regulate cell proliferation, survival, and differentiation. The RAS proteins interact with a common set of activators and effectors; however, they associate with different microdomains of the plasma membrane as well as other endomembranes and are capable of generating distinct signal outputs. Mutations that result in constitutive activation of RAS proteins are associated with ~30% of all human cancers; however, different RAS oncogenes are preferentially associated with different types of human cancer. In myeloid malignancies, NRAS mutations are more frequent than KRAS mutations, whereas HRAS mutations are rare. The mechanism underlying the different frequencies of RAS isoforms mutated in myeloid leukemia is not known. In this study, we compared the leukemogenic potential of activated NRAS, KRAS, and HRAS in the same bone marrow transduction/transplantation model system. We found that all three RAS oncogenes have the ability to induce myeloid leukemias, yet have distinct leukemogenic strengths and phenotypes. The models established here provide a system for further studying the molecular mechanisms in the pathogenesis of myeloid malignancies and for testing targeted therapies. PMID:17671181

  17. 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.

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

    PubMed Central

    2013-01-01

    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. PMID:24279451

  19. Large volcanoes on Venus: Examples of geologic and structural characteristics from different classes

    NASA Technical Reports Server (NTRS)

    Crumpler, L. S.; Head, J. W.; Aubele, J. C.

    1993-01-01

    Large volcanoes characterized by radial lava flows and similar evidence for a topographic edifice are widely distributed over the surface of Venus and geologically diverse. Based on the global identification of more than 165 examples and preliminary geologic mapping, large volcanoes range from those characterized geologically as simple lava edifices to those bearing evidence of complexly developed volcanic and structural histories. Many large volcanoes exhibit characteristics transitional to other large magnetic center types such as coronae and novae. In this study, we examine the geology and structure of several type examples of large volcanoes not addressed in previous studies which are representative of several of the morphological classes.

  20. Large differences in the genome organization of different plant Trypanosomatid parasites ( Phytomonas spp.) reveal wide evolutionary divergences between taxa

    Microsoft Academic Search

    C. Marín; M. Dollet; M. Pagès; P. Bastien

    2009-01-01

    All currently known plant trypanosomes have been grouped in the genus Phytomonas spp., although they can differ greatly in terms of both their biological properties and effects upon the host. Those parasitizing the phloem sap are specifically associated with lethal syndromes in Latin America, such as, phloem necrosis of coffee, ‘Hartrot’ of coconut and ‘Marchitez sorpresiva’ of oil palm, that

  1. Large differences in the genome organization of different plant Trypanosomatid parasites (Phytomonas spp.) reveal wide evolutionary divergences between taxa.

    PubMed

    Marín, C; Dollet, M; Pagès, M; Bastien, P

    2009-03-01

    All currently known plant trypanosomes have been grouped in the genus Phytomonas spp., although they can differ greatly in terms of both their biological properties and effects upon the host. Those parasitizing the phloem sap are specifically associated with lethal syndromes in Latin America, such as, phloem necrosis of coffee, 'Hartrot' of coconut and 'Marchitez sorpresiva' of oil palm, that inflict considerable economic losses in endemic countries. The genomic organization of one group of Phytomonas (D) considered as representative of the genus has been published previously. The present work presents the genomic structure of two representative isolates from the pathogenic phloem-restricted group (H) of Phytomonas, analyzed by pulsed field gel electrophoresis followed by hybridization with chromosome-specific DNA markers. It came as a surprise to observe an extremely different genomic organization in this group as compared with that of group D. Most notably, the chromosome number is 7 in this group (with a genome size of 10 Mb) versus 21 in the group D (totalling 25 Mb). These data unravel an unsuspected genomic diversity within plant trypanosomatids, that may justify a further debate about their division into different genera. PMID:19111630

  2. Differences in kainate receptor involvement in hippocampal mossy fibre long-term potentiation depending on slice orientation.

    PubMed

    Sherwood, John L; Amici, Mascia; Dargan, Sheila L; Culley, Georgia R; Fitzjohn, Stephen M; Jane, David E; Collingridge, Graham L; Lodge, David; Bortolotto, Zuner A

    2012-09-01

    Long-term potentiation (LTP) is a well-established experimental model used to investigate the synaptic basis of learning and memory. LTP at mossy fibre - CA3 synapses in the hippocampus is unusual because it is normally N-methyl-d-aspartate (NMDA) receptor-independent. Instead it seems that the trigger for mossy fibre LTP involves kainate receptors (KARs). Although it is generally accepted that pre-synaptic KARs play an essential role in frequency facilitation and LTP, their subunit composition remains a matter of significant controversy. We have reported previously that both frequency facilitation and LTP can be blocked by selective antagonism of GluK1 (formerly GluR5/Glu(K5))-containing KARs, but other groups have failed to reproduce this effect. Moreover, data from receptor knockout and mRNA expression studies argue against a major role of GluK1, supporting a more central role for GluK2 (formerly GluR6/Glu(K6)). A potential reason underlying the controversy in the pharmacological experiments may reside in differences in the preparations used. Here we show differences in pharmacological sensitivity of synaptic plasticity at mossy fibre - CA3 synapses depend critically on slice orientation. In transverse slices, LTP of fEPSPs was invariably resistant to GluK1-selective antagonists whereas in parasagittal slices LTP was consistently blocked by GluK1-selective antagonists. In addition, there were pronounced differences in the magnitude of frequency facilitation and the sensitivity to the mGlu2/3 receptor agonist DCG-IV. Using anterograde labelling of granule cells we show that slices of both orientations possess intact mossy fibres and both large and small presynaptic boutons. Transverse slices have denser fibre tracts but a smaller proportion of giant mossy fibre boutons. These results further demonstrate a considerable heterogeneity in the functional properties of the mossy fibre projection. PMID:22564530

  3. Large-Scale Weather Influences on Community Air Pollution Potential in the United States

    Microsoft Academic Search

    G. C. Holzworth

    1969-01-01

    This paper describes the large-scale weather features that typically are associated with relatively rapid and slow atmospheric dispersion. Specific examples for some well-known air pollution incidents are illustrated and discussed. Particular attention is paid to the features of quasi-stagnating anticyclones, the typical weather system associated with persistent and extensive areas of sluggish dispersion. On the large scale, the basic quantitative

  4. Potential for large-bodied zooplankton and dreissenids to alter the productivity and autotrophic structure of lakes.

    PubMed

    Higgins, Scott N; Althouse, B; Devlin, S P; Vadeboncoeur, Y; Vander Zanden, M J

    2014-08-01

    While limnological studies have emphasized the importance of grazers on algal biomass and primary production in pelagic habitats, few studies have examined their potential role in altering total ecosystem primary production and it's partitioning between pelagic and benthic habitats. We modified an existing ecosystem production model to include biotic feedbacks associated with two groups of large-bodied grazers of phytoplankton (large-bodied zooplankton and dreissenid mussels) and estimated their effects on total ecosystem production (TEP), and the partitioning of TEP between phytoplankton and periphyton (autotrophic structure) across large gradients in lake size and total phosphorus (TP) concentration. Model results indicated that these filter feeders were capable of reducing whole-lake phytoplankton production by 20-70%, and increasing whole-lake benthic production between 0% and 600%. Grazer effects on TEP were constrained by lake size, trophic status, and potential feedbacks between grazing and maximum rates of benthic photosynthesis (BP(MAX)). In small (mean depth Z < 10 m) oligotrophic and mesotrophic (TP < 100 mg P/m2) lakes, both large-bodied zooplankton and dreissenids were capable of increasing the benthic fraction (Bf) by 10-50% of TEP. Small lakes were also the only systems where TEP had the potential to increase in the presence of large-bodied grazers, but such increases only occurred if grazer-induced changes in water clarity, macrophyte coverage, or nutrient availability stimulated specific growth rates of periphyton. In other scenarios, TEP declined by a maximum of 50%. In very large lakes (Z > 100 m), Bf was minor (< 10%) in the presence or absence of grazers, but increases in littoral habitat and the stimulation of benthic production in these ecosystems could be of ecological relevance because littoral zones in large lakes contain a relatively high proportion of within-lake biodiversity and are important for whole-lake food webs. PMID:25230476

  5. 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 Clo?ani 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 Clo?ani 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 Clo?ani 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 (Clo?ani Cave) show stronger luminescence than the darker/clearer parts. The stalagmite Stam-4 (Clo?ani 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.

  6. 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.

  7. Wavelet analysis of corneal endothelial electrical potential difference reveals cyclic operation of the secretory mechanism

    NASA Astrophysics Data System (ADS)

    Cacace, V. I.; Montalbetti, N.; Kusnier, C.; Gomez, M. P.; Fischbarg, J.

    2011-09-01

    The corneal endothelium is a fluid-transporting epithelium. As other similar tissues, it displays an electrical potential of ˜1 mV (aqueous side negative) across the entire layer [transendothelial potential difference (TEPD)]. It appears that this electrical potential is mainly the result of the transport of anions across the cell layer (from stroma to aqueous). There is substantial evidence that the TEPD is related linearly to fluid transport; hence, under proper conditions, its measure could serve as a measure of fluid transport. Furthermore, the TEPD is not steady; instead, it displays a spectrum of frequency components (0-15 Hz) recognized recently using Fourier transforms. Such frequency components appear due to charge-separating (electrogenic) processes mediated by epithelial plasma membrane proteins (both ionic channels and ionic cotransporters). In particular, the endothelial TEPD oscillations of the highest amplitude (1-2 Hz) were linked to the operation of so-called sodium bicarbonate cotransporters. However, no time localization of that activity could be obtained with the Fourier methodology utilized. For that reason we now characterize the TEPD using wavelet analysis with the aim to localize in time the variations in TEPD. We find that the mentioned high-amplitude oscillatory components of the TEPD appear cyclically during the several hours that an endothelial preparation survives in vitro. They have a period of 4.6 ± 0.4 s on average (n=4). The wavelet power value at the peak of such oscillations is 1.5 ± 0.1 mV2 Hz on average (n = 4), and is remarkably narrow in its distribution.

  8. Electronic structure of CrN: A comparison between different exchange correlation potentials

    NASA Astrophysics Data System (ADS)

    Botana, A. S.; Tran, F.; Pardo, V.; Baldomir, D.; Blaha, P.

    2012-06-01

    We report a series of electronic structure calculations for CrN using different exchange correlation potentials: PBE, LDA+U, the Tran-Blaha modified Becke-Johnson functional, and hybrid functionals. In every case, our calculations show that the onset of magnetism in CrN should be accompanied by a gap opening. The experimentally found antiferromagnetic order always leads to an insulating behavior. Our results give further evidence that the Tran-Blaha functional is very useful for treating the electronic structure of correlated semiconductors allowing a parameter-free description of the system. Hybrid functionals are also well capable of describing the electronic structure of CrN. The analysis of the system is complemented with our calculations of the thermopower that are in agreement with the experimental data.

  9. Efficacy of different adjuvants to potentiate the immune response to mycoplasma strain F-38.

    PubMed

    Mulira, G L; Masiga, W N; Nandokha, E

    1988-02-01

    A study was carried out to determine the efficacy of different adjuvants in enhancing antibody response to sonicated F-38 antigens. Goats were immunised against CCPP using antigens incorporated in Freund's incomplete adjuvant (IFA), saponin, aluminium hydroxide gel and buffered saline (PBS) respectively. Antibody responses were determined. The goats were challenged four months after immunisation to assess their immune status. Two of eight goats given antigen in PBS, six of 10 goats given antigen in aluminium hydroxide, seven of eight goats given antigen in IFA and all 10 goats given antigen in saponin withstood the challenge. Saponin and IFA were similar in their immune potentiation ability and were superior to aluminium hydroxide. As IFA has been considered unsuitable for use in food animals saponin may prove valuable in vaccination of goats against CCPP caused by mycoplasma strain F-38. PMID:3354056

  10. Auditory evoked potentials for the assessment of depth of anaesthesia: different configurations of artefact detection algorithms.

    PubMed

    Luecke, Daniela; Stockmanns, Gudrun; Gallinat, Michael; Kochs, Eberhard F; Schneider, Gerhard

    2007-02-01

    Monitoring the depth of anaesthesia has become an important research topic in the field of biosignal processing. Auditory evoked potentials (AEPs) have been shown to be a promising tool for this purpose. Signals recorded in the noisy environment of an operating theatre are often contaminated by artefacts. Thus, artefact detection and elimination in the underlying electroencephalogram (EEG) are mandatory before AEP extraction. Determination of a suitable artefact detection configuration based on EEG data from a clinical study is described. Artefact detection algorithms and an AEP extraction procedure encompassing the artefact detection results are presented. Different configurations of artefact detection algorithms are evaluated using an AEP verification procedure and support vector machines to determine a suitable configuration for the assessment of depth of anaesthesia using AEPs. PMID:17313341

  11. 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.

  12. Proficiency Differences in Syntactic Processing of Monolingual Native Speakers Indexed by Event-related Potentials

    PubMed Central

    Pakulak, Eric; Neville, Helen J.

    2010-01-01

    While anecdotally there appear to be differences in the way native speakers use and comprehend their native language, most empirical investigations of language processing study university students and none have studied differences in language proficiency which may be independent of resource limitations such as working memory span. We examined differences in language proficiency in adult monolingual native speakers of English using an event-related potential (ERP) paradigm. ERPs were recorded to insertion phrase structure violations in naturally spoken English sentences. Participants recruited from a wide spectrum of society were given standardized measures of English language proficiency, and two complementary ERP analyses were performed. In between-groups analyses, participants were divided, based on standardized proficiency scores, into Lower Proficiency (LP) and Higher Proficiency (HP) groups. Compared to LP participants, HP participants showed an early anterior negativity that was more focal, both spatially and temporally, and a larger and more widely distributed positivity (P600) to violations. In correlational analyses, we utilized a wide spectrum of proficiency scores to examine the degree to which individual proficiency scores correlated with individual neural responses to syntactic violations in regions and time windows identified in the between-group analyses. This approach also employed partial correlation analyses to control for possible confounding variables. These analyses provided evidence for the effects of proficiency that converged with the between-groups analyses. These results suggest that adult monolingual native speakers of English who vary in language proficiency differ in the recruitment of syntactic processes that are hypothesized to be at least in part automatic as well as of those thought to be more controlled. These results also suggest that in order to fully characterize neural organization for language in native speakers it is necessary to include participants of varying proficiency. PMID:19925188

  13. 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.

  14. Ab Initio Calculation of the Helium-Helium 1Sigmag+ Potential at Intermediate and Large Separations

    Microsoft Academic Search

    P. Bertoncini; Arnold C. Wahl

    1970-01-01

    A five-configuration wave function computed by multiconfiguration self-consistent field techniques has yielded a well depth ?k=10.48°K at rm=5.659 bohrs and a potential zero sigma=5.037 bohrs for the interaction of ground-state He atoms. Improvement of the basis set yields, at R=5.60, a potential U(R)=11.38°K. It is suggested that calculations in the vein of the present approximation should converge to a well

  15. 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.; Gonçalves, 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.

  16. 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…

  17. Rigorous Derivation of the Gross-Pitaevskii Equation with a Large Interaction Potential

    E-print Network

    Laszlo Erdos; Benjamin Schlein; Horng-Tzer Yau

    2009-03-16

    Consider a system of $N$ bosons in three dimensions interacting via a repulsive short range pair potential $N^2V(N(x_i-x_j))$, where $\\bx=(x_1, >..., x_N)$ denotes the positions of the particles. Let $H_N$ denote the Hamiltonian of the system and let $\\psi_{N,t}$ be the solution to the Schr\\"odinger equation. Suppose that the initial data $\\psi_{N,0}$ satisfies the energy condition \\[ \\leq C N >. \\] and that the one-particle density matrix converges to a projection as $N \\to \\infty$. Then, we prove that the $k$-particle density matrices of $\\psi_{N,t}$ factorize in the limit $N \\to \\infty$. Moreover, the one particle orbital wave function solves the time-dependent Gross-Pitaevskii equation, a cubic non-linear Schr\\"odinger equation with the coupling constant proportional to the scattering length of the potential $V$. In \\cite{ESY}, we proved the same statement under the condition that the interaction potential $V$ is sufficiently small; in the present work we develop a new approach that requires no restriction on the size of the potential.

  18. Potential of High Speed, Short Distance Optical Data Communication on Large Diameter Optical Fibers

    Microsoft Academic Search

    O. Ziemann; H. Poisel; J. Vinogradov

    2006-01-01

    Optical communication systems offer a big number of advantages compared with wireless and copper based systems: no EMI, high capacity and potential free connection. The big disadvantages are the difficult installation and the price of the active components. The use of thick optical fibers like polymer optical fibers or polymer clad silica fibers enables very simple installation and packaging technologies.

  19. Collective Potential for LargeN Hamiltonian Matrix Models and Free Fisher Information

    Microsoft Academic Search

    A. Agarwal; L. Akant; G. S. Krishnaswami; S. G. Rajeev

    2003-01-01

    We formulate the planar ``large N limit'' of matrix models with a continuously infinite number of matrices directly in terms of U(N) invariant variables. Noncommutative probability theory is found to be a good language to describe this formulation. The change of variables from matrix elements to invariants induces an extra term in the Hamiltonian, which is crucial in determining the

  20. International Large-Scale Assessments: Challenges in Reporting and Potentials for Secondary Analysis

    ERIC Educational Resources Information Center

    Torney-Purta, Judith; Amadeo, Jo-Ann

    2013-01-01

    International Large-Scale Assessments (ILSAs) have been used to draw comparisons among countries on a variety of topics in education and, more broadly, for example, in adolescent development. These assessments can inform the public about influential factors on the micro and macro levels, foster interdisciplinary and international collaboration,…

  1. Grazing Optimization and Nutrient Cycling: Potential Impact of Large Herbivores in a Savanna System

    Microsoft Academic Search

    Claire de Mazancourt; Michel Loreau; Luc Abbadie

    1999-01-01

    Using a model, we test the prediction that herbivory can result in grazing optimization of primary production in a nitrogen-limited system where large losses of nitrogen occur in annual fires. The model is based on the nitrogen budget of the humid savanna of Lamto, Ivory Coast, estimated from field data. At present, the ecosystem contains few herbivores, but buffalo and

  2. Mapping soil water holding capacity over large areas to predict potential production of forest stands

    Microsoft Academic Search

    Christian Piedallu; Jean-Claude Gégout; Ary Bruand; Ingrid Seynave

    2011-01-01

    Ecological studies require environmental descriptors to establish the response of species or communities to ecological conditions. The soil water resource is an important factor, but it is difficult for plant ecologists to use because of the lack of accessible data. We explored whether collecting a large number of plots with basic soil information within the framework of forest inventories would

  3. Normative data for vestibular evoked myogenic potential in different age groups among a heterogeneous Indian population.

    PubMed

    Khan, Feroze K; Balraj, Achamma; Lepcha, Anjali

    2014-06-01

    To establish normative data of vestibular evoked myogenic potential in different age groups among a heterogeneous Indian population. Prospective study design using a sample of convenience. Eighty five normal controls ranging between the ages 7 and 71 years were asked to provide a written signed consent for the study. Demographic characteristics of the patients were summarized using descriptive statistical methods using SPSS-17 analysing software. The outcome variable (VEMP recording) was expressed in percentiles as function of age. In all patients the stimulus which gave the best response was 95 dB (97.7 %) and 100 dB (95 %). The mean of wave latencies (p1 & n1) for 95-VEMP were, 11.2 ± 3.2 and 17.3 ± 4.7 ms on the right and 11.0 ± 2.8 and 17.0 ± 4.2 ms on the left respectively. The amplitude was 45.1 ± 54 mV on right and 46.9 ± 61.6 mV on the left. The mean of latency difference was 0.87 ms. The VEMP is a relatively simple test. The VEMP response rate was maximum in the younger age group; the optimum intensity was 95 dB. The asymmetry ratio interpretation should be done according to the age specific values. PMID:24822153

  4. Effects of DAGO on the rodent hippocampal evoked potentials using different perfusion solutions.

    PubMed

    SanMartín, S; Menéndez, L; Gutiérrez, M; Hidalgo, A; Baamonde, A

    2000-01-01

    Opioid receptor agonists exert excitatory effects in the hippocampus by inhibiting GABA release. We report that the mu-opioid agonist, DAGO, increases the amplitude of the population spikes (PS) measured in the stratum pyramidale of the CA1 cell layer in mouse and rat hippocampal slices perfused with an artificial cerebrospinal fluid (ACSF), but not when perfused in Krebs solution. The GABAA agonist, 3-APS, induces inhibitory responses when perfused in either ACSF or Krebs. Also, the field excitatory postsynaptic potentials (EPSP) measured on stratum radiatum do not differ when the slice is perfused with either ACSF or Krebs. The increase in the amplitude of the PS induced by DAGO is not obtained when perfused in a modified. ACSF whose concentration of MgSO4 was lowered to its concentration in the Krebs solution (from 2.4 mM to 1.2 mM). Thus, changes in the concentration of MgSO4 seem to be responsible for the different responses induced by DAGO. PMID:10909174

  5. Different immune regulatory potential of Lactobacillus plantarum and Lactobacillus sakei isolated from Kimchi.

    PubMed

    Hong, Yi-Fan; Kim, Hangeun; Kim, Hye Rim; Gim, Min Geun; Chung, Dae Kyun

    2014-12-28

    It is known that lactic acid bacteria (LAB) have many beneficial health effects, including antioxidative activity and immune regulation. In this study, the immune regulatory effects of Lactobacillus sakei and Lactobacillus plantarum, which are found in different types of kimchi, were evaluated. L. sakei and its lipoteichoic acid (LTA) have greater immune stimulating potential in IL-12, IFN-?, and TNF-? production as compared with L. plantarum in an in vitro condition. On the other hand, L. plantarum is assumed to repress the Th1 immune response in murine experiments. After being injected with LPS, L. plantarum-fed mice maintained a healthier state, and the level of TNF-? in their blood was lower than in other bacterial strainfed mice and in the LPS-only control mice. Additionally, IL-12 production was significantly decreased and the production of IL-4 was greatly increased in the splenocytes from L. plantarum-fed mice. Further experiments revealed that the pre-injection of purified LTA from L. plantarum (pLTA), L. sakei (sLTA), and S. aureus (aLTA) decreased TNF-? and IL-4 production in LPS-injected mice. Mouse IL-12, however, was significantly increased by aLTA pre-injection. In conclusion, the L. sakei and L. plantarum strains have immune regulation effects, but the effects differ in cytokine production and the regulatory effects of the Th1/Th2 immune response. PMID:25112321

  6. Resting transmembrane potential difference of skeletal muscle in normal subjects and severely ill patients

    PubMed Central

    Cunningham, J. N.; Carter, N. W.; Rector, F. C.; Seldin, D. W.

    1971-01-01

    The resting membrane potential difference (Em) of skeletal muscle was measured in 26 normal human subjects, 7 patients with mild illness, and 21 patients with severe, debilitating medical disorders. A closed transcutaneous approach to the muscle was made by needle puncture and the Em was measured utilizing standard Ling electrodes. Measurements revealed an Em of -88 ±3.8 mv in healthy subjects and -89 ±2.1 mv in patients hospitalized for minor medical problems. The mean Em in 21 in-hospital patients, judged to be severely ill clinically from a variety of causes, was -66.3 ±9.0 mv. Open deltoid muscle biopsies were performed in 7 of the healthy subjects and in 13 of the severely ill group. Estimation of the intra-extracellular water partition was made by calculating the chloride space from the previously measured Em. Analysis of the muscle samples revealed no significant difference in the intra-extracellular potassium ratios of the two groups biopsied. Intracellular Na+ concentrations were uniformly increased in the muscle samples of the severely ill subjects and averaged 42.3% higher than those of the normal subjects. The mechanisms which might account for the elevation of intracellular Na+ and a depression of Em independent of changes in intra-extracellular K+ ratios are discussed and it is suggested that this defect may be a generalized cellular abnormality which is a common quality of serious illnesses. PMID:5101298

  7. Effect of different types of conditioning contraction on upper body postactivation potentiation.

    PubMed

    Esformes, Joseph I; Keenan, Matthew; Moody, Jeremy; Bampouras, Theodoros M

    2011-01-01

    Muscle contractions preceding an activity can result in increased force generation (postactivation potentiation [PAP]). Although the type of muscular contractions could affect subsequent strength and power performance, little information exists on their effects. The purpose of this study was to examine PAP effects produced by isometric (ISO), concentric (CON), eccentric (ECC), or concentric-eccentric (DYN) conditioning contractions on upper body force and power performance. Ten male, competitive rugby players (mean ± SD: age 20.4 ± 0.8 years, height 177.0 ± 8.1 cm, body mass 90.2 ± 13.8 kg) performed a ballistic bench press throw (BBPT) followed by a 10-minute rest and one of the conditioning contractions. After a 12-minute rest, the subjects performed another BBPT (post-BBPT). The conditioning contractions, applied on separate days and in counterbalanced randomized order, were a 7-second isometric barbell bench press for ISO and 1 set of 3 bench press repetitions at 3 repetition maximum for CON, ECC, and DYN (each repetition lasting 2 seconds for CON and ECC, overall execution time <7 seconds for DYN). Peak power (Ppeak), peak force (Fpeak), maximum distance (Dmax) and rate of force development (RFD) were measured using a linear position transducer. Electromyography (EMG) of the pectoralis major and triceps brachii was also recorded. The ISO produced significantly higher Ppeak (587 ± 116 and 605 ± 126 W for pre- and post-BBPT, respectively; p < 0.05). No significant differences in Ppeak were revealed for CON, ECC, and DYN (p > 0.05), and no significant differences existed in Fpeak, Dmax, and RFD for ISO, CON, ECC, and DYN (p > 0.05). Finally, EMG was not significantly different between pre- and post-BBPT for any of the conditioning contractions (p > 0.05). Isometric contractions appear to be the only conditioning contractions increasing upper body power output after long resting periods. PMID:21157387

  8. Recruitment potential of two perennial grasses with different growth forms at a semiarid-arid transition zone

    Microsoft Academic Search

    DEBRA P. C. PETERS

    2002-01-01

    The objective of this study was to quantify differences in recruitment potential (seed production, seed presence in the soil) for two congeneric perennial grasses (Bouteloua gracilis, Bouteloua eriopoda (Poaceae)) that dominate adjacent arid and semiarid grassland biomes. It was hypothesized that these species have different recruitment strategies at the biome transition zone that are related to differences in their growth

  9. 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.

  10. Collective potential for large N hamiltonian matrix models and free Fisher information

    Microsoft Academic Search

    A. AgarwalL; G. S. Krishnaswami; S. G. Rajeev

    2002-01-01

    We formulate the planar `large N limit' of matrix models with a continuously\\u000ainfinite number of matrices directly in terms of U(N) invariant variables.\\u000aNon-commutative probability theory, is found to be a good language to describe\\u000athis formulation. The change of variables from matrix elements to invariants\\u000ainduces an extra term in the hamiltonian,which is crucual in determining the\\u000aground

  11. 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.

  12. Large breasts and narrow waists indicate high reproductive potential in women.

    PubMed Central

    Jasie?ska, Grazyna; Ziomkiewicz, Anna; Ellison, Peter T.; Lipson, Susan F.; Thune, Inger

    2004-01-01

    Physical characteristics, such as breast size and waist-to-hip ratio (WHR), function as important features used by human males to assess female attractiveness. Males supposedly pay attention to these features because they serve as cues to fecundity and health. Here, we document that women with higher breast-to-underbreast ratio (large breasts) and women with relatively low WHR (narrow waists) have higher fecundity as assessed by precise measurements of daily levels of 17-beta-oestradiol (E2) and progesterone. Furthermore, women who are characterized by both narrow waists and large breasts have 26% higher mean E2 and 37% higher mean mid-cycle E2 levels than women from three groups with other combinations of body-shape variables, i.e. low WHR with small breasts and high WHR with either large or small breasts. Such gains in hormone levels among the preferred mates may lead to a substantial rise in the probability of conception, thus providing a significant fitness benefit. PMID:15306344

  13. Shannon bounds for large-scale wireless MAC's potential capacity in presence of errors

    Microsoft Academic Search

    Alexander B. Markhasin

    2008-01-01

    The reachable, real, throughput capacity of the various medium access control (MAC) protocols differs considerably. In fact, a wireless MAC protocol's current state information is dispersed at geographically distributed stations, and therefore is inaccessible in principle for the \\

  14. 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 (?v). Average ?v was inversely related to bulk root water potential (?(root)). In turn, ?(root) was correlated with both average [ABA](root) and [RX-ABA](sap). Despite large gradients in ?v, [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

  15. 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.; Lück, 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.

  16. Sex differences in ?-adrenergic responsiveness of action potentials and intracellular calcium handling in isolated rabbit hearts.

    PubMed

    Hoeker, Gregory S; Hood, Ashleigh R; Katra, Rodolphe P; Poelzing, Steven; Pogwizd, Steven M

    2014-01-01

    Cardioprotection in females, as observed in the setting of heart failure, has been attributed to sex differences in intracellular calcium handling and its modulation by ?-adrenergic signaling. However, further studies examining sex differences in ?-adrenergic responsiveness have yielded inconsistent results and have mostly been limited to studies of contractility, ion channel function, or calcium handling alone. Given the close interaction of the action potential (AP) and intracellular calcium transient (CaT) through the process of excitation-contraction coupling, the need for studies exploring the relationship between agonist-induced AP and calcium handling changes in female and male hearts is evident. Thus, the aim of this study was to use optical mapping to examine sex differences in ventricular APs and CaTs measured simultaneously from Langendorff-perfused hearts isolated from naïve adult rabbits during ?-adrenergic stimulation. The non-selective ?-agonist isoproterenol (Iso) decreased AP duration (APD90), CaT duration (CaD80), and the decay constant of the CaT (?) in a dose-dependent manner (1-316.2 nM), with a plateau at doses ?31.6 nM. The Iso-induced changes in APD90 and ? (but not CaD80) were significantly smaller in female than male hearts. These sex differences were more significant at faster (5.5 Hz) than resting rates (3 Hz). Treatment with Iso led to the development of spontaneous calcium release (SCR) with a dose threshold of 31.6 nM. While SCR occurrence was similar in female (49%) and male (53%) hearts, the associated ectopic beats had a lower frequency of occurrence (16% versus 40%) and higher threshold (100 nM versus 31.6 nM) in female than male hearts (p<0.05). In conclusion, female hearts had a decreased capacity to respond to ?-adrenergic stimulation, particularly under conditions of increased demand (i.e. faster pacing rates and "maximal" levels of Iso effects), however this reduced ?-adrenergic responsiveness of female hearts was associated with reduced arrhythmic activity. PMID:25340795

  17. 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

  18. A refined quartic potential energy surface and large scale vibrational calculations for S0 thiophosgene.

    PubMed

    Rashev, Svetoslav; Moule, David C

    2015-04-01

    In this work we present a full 6D quartic potential energy surface (PES) for S0 thiophosgene in curvilinear symmetrized bond-angle coordinates. The PES was refined starting from an ab initio field derived from acc-pVTZ basis set with CCSD(T) corrections for electron correlation. In the present calculations we used our variational method that was recently tested on formaldehyde and some of its isotopomers, along with additional improvements. The lower experimentally known vibrational levels for 35Cl2CS were reproduced quite well in the calculations, which can be regarded as a test for the feasibility of the obtained quartic PES. PMID:25615683

  19. A refined quartic potential energy surface and large scale vibrational calculations for S0 thiophosgene

    NASA Astrophysics Data System (ADS)

    Rashev, Svetoslav; Moule, David C.

    2015-04-01

    In this work we present a full 6D quartic potential energy surface (PES) for S0 thiophosgene in curvilinear symmetrized bond-angle coordinates. The PES was refined starting from an ab initio field derived from acc-pVTZ basis set with CCSD(T) corrections for electron correlation. In the present calculations we used our variational method that was recently tested on formaldehyde and some of its isotopomers, along with additional improvements. The lower experimentally known vibrational levels for 35Cl2CS were reproduced quite well in the calculations, which can be regarded as a test for the feasibility of the obtained quartic PES.

  20. 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.

  1. 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.

  2. Adult and cord blood endothelial progenitor cells have different gene expression profiles and immunogenic potential

    PubMed Central

    Nuzzolo, Eugenia R.; Capodimonti, Sara; Martini, Maurizio; Iachininoto, Maria G.; Bianchi, Maria; Cocomazzi, Alessandra; Zini, Gina; Leone, Giuseppe; Larocca, Luigi M.; Teofili, Luciana

    2014-01-01

    Background Endothelial colony-forming cells (ECFC) are endowed with vascular regenerative ability in vivo and in vitro. In this study we compared the genotypic profile and the immunogenic potential of adult and cord blood ECFC, in order to explore the feasibility of using them as a cell therapy product. Materials and methods ECFC were obtained from cord blood samples not suitable for haematopoietic stem cell transplantation and from adult healthy blood donors after informed consent. Genotypes were analysed by commercially available microarray assays and results were confirmed by real-time polymerase chain reaction analysis. HLA antigen expression was evaluated by flow-cytometry. Immunogenic capacity was investigated by evaluating the activation of allogeneic lymphocytes and monocytes in co-cultures with ECFC. Results Microarray assays revealed that the genetic profile of cord blood and adult ECFC differed in about 20% of examined genes. We found that cord blood ECFC were characterised by lower pro-inflammatory and pro-thrombotic gene expression as compared to adult ECFC. Furthermore, whereas cord blood and adult ECFCs expressed similar amount of HLA molecules both at baseline and after incubation with ?-interferon, cord blood ECFC elicited a weaker expression of pro-inflammatory cytokine genes. Finally, we observed no differences in the amount of HLA antigens expressed among cord blood ECFC, adult ECFC and mesenchymal cells. Conclusions Our observations suggest that cord blood ECFC have a lower pro-inflammatory and pro-thrombotic profile than adult ECFC. These preliminary data offer level-headed evidence to use cord blood ECFC as a cell therapy product in vascular diseases. PMID:23867184

  3. Effect of different soil textures on leaching potential and degradation of pesticides in biobeds.

    PubMed

    Fogg, Paul; Boxall, Alistair B A; Walker, Allan; Jukes, Andrew

    2004-09-01

    Biobeds can be used to intercept pesticide-contaminated runoff from the mixing/washdown area, creating optimum conditions for sorption and biodegradation such that the amount of pesticide reaching adjacent water bodies is significantly reduced. The biobed is built on the farm using locally available materials, which include, straw, compost, and topsoil. The topsoil acts as the inoculum for the system and is likely to vary in terms of its physical, chemical, and microbiological characteristics from one farm to another. This study therefore investigated the effects of using different soil types on the degradation and leaching potential from biobeds. Three contrasting topsoils were investigated. Leaching studies were performed using isoproturon, dimethoate, and mecoprop-P, which were applied at simulated disposal rates to 1.5 m deep biobeds. Annual average concentrations were similar for each soil type with leaching losses of even the most mobile (Koc = 12-25) pesticide <1.64% of the applied dose. Greater than 98% of the retained pesticides were degraded in all matrices. Degradation studies investigated the persistence of individual pesticides and pesticide mixtures in the different matrices. DT50 values for isoproturon, chlorothalonil, mecoprop-P, and metsulfuron-methyl applied at 4 times the maximum approved rate were similar across the biomix types and were all less than or equal to reported DT50 values for soil treated at approved rates. When applied as a mixture, DT50 values in each biomix increased, indicating that interactions between pesticides are possible. However, DT90 values of <167 days were obtained in all circumstances, indicating a negligible risk of accumulation. Studies therefore indicate that substrate will have little impact on biobed performance so it should be possible to use local soils in the construction process. PMID:15373405

  4. 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

  5. Dependence of the energy of vanishing flow on different components of the nuclear potential

    NASA Astrophysics Data System (ADS)

    Kaur, Mandeep; Kaur, Varinderjit; Kumar, Suneel

    2013-11-01

    The contribution of various components of potential towards balance energy is analyzed for the reactions of 2658Fe+2658Fe, 2858Ni+2858Ni, 3686Kr+4193Nb, and 79197Au+79197Au using an isospin-dependent quantum molecular dynamics (IQMD) model. We show that the balance energy changes with the addition of various components of potentials. Our calculations for the considered energy range clearly demonstrate the dominance of the Coulomb potential and momentum-dependent interactions over the other potentials for the lighter colliding systems. However, the contribution of the symmetry potential also becomes significant while handling heavier nuclei.

  6. 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.

  7. Phytochemical screening, antioxidants and antimicrobial potential of Lantana camara in different solvents

    PubMed Central

    Naz, Rabia; Bano, Asghari

    2013-01-01

    Objective To evaluate the antioxidant activity, hydrogen peroxide radicals scavenging activity, reducing power, the total phenolic and flavonoids contents, and antimicrobial and antifungal activities of methanol, ethanol and water extracts of leaves of Lantana camara (L. camara). Methods Methanol, ethanol and water extracts were evaluated against four Gram positive and Gram negative bacterial isolates (Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus subtilis) and two fungal strains (Aspergillus fumigatus and Aspergillus flavus). Methanol extract at different concentrations was tested for antioxidant potential and phytochemicals were determined by using spectrophotometric method. Results The total phenolic content was (40.859±0.017) mg gallic acid/g in the leaves of L. camara, while the total flavonoids was (53.112±0.199) mg/g dry weight. Methanol leaf extract of L. camara showed maximum antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa and was also effective against other bacterial strains as compared to ethanol and aqueous extracts of leaves. The methanol leaf extract of L. camara exhibited significant inhibition (71%) and (66%) against Aspergillus fumigatus and Aspergillus flavus respectively. Conclusions The methanol extract of the L. camara leaves is effective against selected bacterial and fungal strains. Its phytochemical contents have broad antimicrobial properties and the plant might be a novel source of antimicrobial drug.

  8. Inhibition and biotransformation potential of veterinary ionophore antibiotics under different redox conditions.

    PubMed

    Sun, Peizhe; Huang, Ching-Hua; Pavlostathis, Spyros G

    2014-11-18

    Veterinary ionophore antibiotics (IPAs) are polyether compounds used extensively in the livestock industry to promote animal growth and prevent coccidia infection. However, the environmental fate and impact of IPAs are not fully understood. In this study, the inhibition and biotransformation potential of the most commonly used IPAs, monensin (MON) and salinomycin (SAL), were investigated under well-defined aerobic, nitrate-reducing, fermentative/sulfate-reducing, and fermentative/methanogenic conditions. Batch assays were conducted with mixed cultures developed from poultry litter (PL), PL-fertilized soil, and municipal anaerobic sludge. Significant transformation of MON and SAL was observed in aerobic, low-buffer capacity culture series as a result of abiotic acid-catalyzed IPAs hydrolysis induced by nitrification. Biotransformation of IPAs was the main transformation process in aerobic, high-buffer capacity culture series. MON persisted under fermentative/sulfate-reducing conditions, whereas SAL was transformed by fermentative bacteria. Both MON and SAL were stable under nitrate-reducing and methanogenic conditions. At IPAs concentrations up to 1 mg/L, MON inhibited only methanogenesis, whereas SAL did not impact any of the biological processes investigated in this study. Multiple, new primary IPA biotransformation products were observed on LC/MS, and their molecular structures were tentatively identified by analyzing LC/MS/MS fragmentation patterns. Overall, MON and SAL exhibited different inhibition and biotransformation patterns at each redox condition tested, which could greatly influence their fate and impact upon their release into the environment as a result of agricultural activities. PMID:25340528

  9. Prebiotic potential of Agave angustifolia Haw fructans with different degrees of polymerization.

    PubMed

    Velázquez-Martínez, José Rodolfo; González-Cervantes, Rina M; Hernández-Gallegos, Minerva Aurora; Mendiola, Roberto Campos; Aparicio, Antonio R Jiménez; 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

  10. 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

  11. Floating potential of a small particle in a plasma: Difference between Maxwellian and Druyvesteyn electron velocity distributions

    SciTech Connect

    Khrapak, Sergey [Max-Planck-Institut fuer Extraterrestrische Physik, D-85741 Garching (Germany) and Joint Institute for High Temperatures, 125412 Moscow (Russian Federation)

    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. [Effect of chronic inhaled pollutants (cigarette smoke) on trans-epithelial measured potential difference of nasal mucosa in the human].

    PubMed

    Fischer, J; Dahmen, K; Jackowski, M

    1990-02-01

    The transepithelial potential difference of the mucosa of the nose is appreciably higher in non-smokers than in smokers with a moderate to heavy cigarette consumption. This reduced potential difference in response to chronic inhalation to noxae (cigarette smoke) is a marker for the change in the integrity of the mucosa of the nose, and may possibly be considered to be representative of the rest of the respiratory epithelium of the bronchial system. PMID:1694999

  13. Habitat fragmentation in an urban environment: large and small fragments support different arthropod assemblages

    Microsoft Academic Search

    Heloise Gibb; Dieter F. Hochuli

    2002-01-01

    We investigated the effects of fragmentation due to urbanisation on the species composition and functional roles of ants, beetles, spiders, flies and wasps. The study was conducted in 21 fragments of heath and woodland in south-eastern Australia classed as either ‘small’ (? 4 km2) or ‘large’ (? 80 km2). Arthropods were pitfall-trapped and identified to family or genus and morphospecies

  14. Mapping soil water holding capacity over large areas to predict the potential production of forest stands

    E-print Network

    Paris-Sud XI, Université de

    different from those used to calibrate them. With a root mean squared error (RMSE) of 0.046 cm3 cm-3 (n for Fagus sylvatica, Picea abies and Quercus petraea is discussed. We show a much better predictive ability.1% for Quercus petraea (n = 877) and 10.3% for Picea abies (n = 2067). The proportions of variance accounted

  15. 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…

  16. Occupational Stress of Teachers: Biographical Differences in a Large School System.

    ERIC Educational Resources Information Center

    McCormick, John

    1997-01-01

    Explores significant differences in occupational stress between groups of public school teachers in New South Wales, Australia. Underlines the importance of differentiating between executive and classroom teachers, elementary and secondary teachers, and teachers at different career stages and geographical locations when considering stress…

  17. Occupational stress of teachers: biographical differences in a large school system

    Microsoft Academic Search

    John McCormick

    1997-01-01

    Presents the results of an analysis of questionnaire and interview data revealing significant differences in occupational stress between groups of public school teachers, in New South Wales, Australia. In particular, emphasizes the importance of differentiating between executive and classroom teachers, primary\\/infants and secondary teachers, teachers at different career stages and teachers in geographical locations, when planning to alleviate stress in

  18. 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.

  19. 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.

  20. Potential contribution of MDI to understanding large-scale structures in the corona

    NASA Technical Reports Server (NTRS)

    Zhao, Xuepu; Hoeksema, J. Todd; Scherrer, Phil H.

    1995-01-01

    In relation to the understanding of the structure and dynamics of the solar atmosphere which requires realistic coronal magnetic field models, a horizontal current-current sheet (HCCS) coronal model was developed. The model includes large-scale, low altitude, horizontal currents and the effect of thin current sheets in the streamer belt of the field above cusp-type neutral points. The effect of the streamer current sheet on the field below the cusp points is accounted for. In order to suggest what can be anticipated from Michelson Doppler imager (MDI) photospheric magnetic field data calculations of the coronal magnetic field using low spatial resolution data, are presented, and results from the calculations of solar eclipses are compared with solar eclipse images.

  1. 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.; Östling, 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.

  2. Toward understanding the large-scale land-atmosphere coupling in the models: Roles of different processes

    NASA Astrophysics Data System (ADS)

    Wei, Jiangfeng; Dirmeyer, Paul A.

    2010-10-01

    Two different Atmospheric General Circulation Models (AGCMs), each coupled to three different land surface schemes (LSSs) (six different model configurations in total), are used to study the roles of different model components and different action processes in land-atmosphere coupling. Experiments show that, for the six model configurations, the choice of AGCMs is the main reason for the substantially different precipitation variability, predictability, and land-atmosphere coupling strength among the configurations. The impact of different LSSs is secondary. Intraseasonal precipitation variability, which is mainly a property of the AGCM, can impact land-atmosphere coupling both directly in the atmosphere and indirectly through soil moisture response to precipitation. These results lead to a common conceptual decomposition of the land-atmosphere coupling strength and increases the understanding on large-scale land-atmosphere coupling.

  3. 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

  4. Integral representation of voltage in half-plane conductor with embedded crack by D.C. potential difference method

    NASA Astrophysics Data System (ADS)

    Akira, Sasamoto; Krutitskii, P. A.

    2013-10-01

    Non destructive testing (NDT) has been used to ensure safety in public structure and public space. D.C. potential difference method, one of the NDT, is used to detect a crack in a conductive material. In this paper we obtain an exact solution for model equation for D.C. potential difference method, which is the Laplace equation with an embedded crack in two dimensional half-space by using singular integral equation and angular potential. The solution can be computed and is useful for actual investigation of a crack.

  5. 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

  6. Alternative transcription start site selection leads to large differences in translation activity in yeast

    E-print Network

    Rojas-Duran, Maria F.

    mRNA levels do not accurately predict protein levels in eukaryotic cells. To investigate contributions of 5? untranslated regions (5? UTRs) to mRNA-specific differences in translation, we determined the 5? UTR boundaries ...

  7. Do males and females differ in the feeding of large and small siblings? An experiment with the bluethroat

    Microsoft Academic Search

    Per T. Smiseth; Trond Amundsen; Lars T. T. Hansen

    1998-01-01

    Males and females have been reported to differ in their feeding of large and small siblings in several species of birds.\\u000a According to recent hypotheses, this phenomenon may be related to a sexual conflict over avian hatching patterns. We designed\\u000a an experiment to test for the existence of such a sex difference by manipulating nestling size hierarchies of the bluethroat

  8. Cross-national price differences for pharmaceuticals: how large, and why?

    Microsoft Academic Search

    Patricia M. Danzon; Li-Wei Chao

    2000-01-01

    Bilateral drug price and quantity indexes, based on comprehensive data for seven countries (US, Canada, France, Germany, Italy, Japan and the UK), refute the conventional wisdom that US drug prices are much higher than elsewhere, for Laspeyres (US-weighted) indexes. Previous drug-price comparisons are biased by unrepresentative samples and unweighted indexes. Quasi-hedonic regression shows that cross-national price differences reflect differences in

  9. Testing different ecological scenarios in a temperate estuary: a contribution towards the implementation of the Ecological Potential assessment.

    PubMed

    Veríssimo, Helena; Patrício, Joana; Teixeira, Heliana; Carriço, Ana; Marques, João Carlos

    2013-06-15

    The concept of Ecological Potential was explored using the macrobenthic communities of the Mondego estuary (Portugal). Different scenarios (loss of a primary producer and intertidal habitat, and habitat modification due to hydromorphological changes and continued press perturbation) were tested to predict changes in the biology if hydromorphological pressures could be reversed, assuming that differences with and without the pressure could indicate the potential. Results showed noticeable changes in the system biology in each scenario. The approach followed, indicates that when data sets exist, differences in the measurement of ecological status with and without the hydromorphological change could be a way forward to determine the potential. In the particular case of the Mondego estuary, the South arm (physically unaltered water body) proved to be richer than the North (HMWB). For the Ecological Potential determination, the South arm could thus be used to derive and adjust future reference conditions for the North. PMID:23628548

  10. 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

  11. Inhibition and biotransformation potential of naphthenic acids under different electron accepting conditions.

    PubMed

    Misiti, Teresa; Tandukar, Madan; Tezel, Ulas; Pavlostathis, Spyros G

    2013-01-01

    Naphthenic acids (NAs) are a complex group of alkyl-substituted acyclic, monocyclic and polycyclic carboxylic acids present in crude oil, oil sands process water and tailings ponds, as well as in refinery wastewater. Bioassays were performed to investigate the biotransformation potential and inhibitory effect of a commercial NA mixture to nitrification, denitrification and fermentation/methanogenesis using mixed cultures not previously exposed to NAs. NAs inhibited nitrification in a mixed aerobic heterotrophic/nitrifying culture at concentrations as low as 80 mg NA/L, whereas, an enriched nitrifying culture was only affected at 400 mg NA/L. The lower nitrification inhibition in the latter assay is attributed to the higher population size of nitrosofying and nitrifying bacteria compared to the mixed heterotrophic/nitrifying culture. The NA mixture was not inhibitory to denitrifiers up to 400 mg/L. At higher NA concentrations, cell lysis was pronounced and lysis products were the main source of degradable carbon driving denitrification in culture series prepared without an external carbon source. In the presence of a degradable external carbon source, no difference was observed in nitrate reduction rates or nitrogen gas production at all NA concentrations tested. Methanogenesis was completely inhibited at NA concentrations equal to or higher than 200 mg/L. Methanogenic culture series amended with 80 mg NA/L were transiently inhibited and methane production in culture series prepared with NAs and an external carbon source or NAs only recovered in 136 and 41 days, respectively. Accumulation of volatile fatty acids was observed at inhibitory NA concentrations; however, carbon dioxide production was not affected by NAs, indicating that fermentation and acidogenesis were not affected by NAs. NAs were not degraded under nitrate-reducing or fermentative/methanogenic conditions used in the present study, regardless of the presence or not of another, degradable carbon/energy source. PMID:23134740

  12. 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.

  13. 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.

  14. An Aspergillus chitosanase with potential for large-scale preparation of chitosan oligosaccharides.

    PubMed

    Cheng, C Y; Li, Y K

    2000-12-01

    A chitosan-degrading fungus, designated Aspergillus sp. Y2K, was isolated from soil. The micro-organism was used for producing chitosanase (EC 3.2.1.132) in a minimal medium containing chitosan as the sole carbon source. The induced chitosanase was purified to homogeneity from the culture filtrate by concentration and cationic SP-Sepharose chromatography. The purified enzyme is a monomer with an estimated molecular mass of 25 kDa by SDS/PAGE and of 22 kDa by gel-filtration chromatography. pI, optimum pH and optimum temperature values were 8.4, 6.5 and 65-70 degrees C, respectively. The chitosanase is stable in the pH range from 4 to 7.5 at 55 degrees C. Higher deacetylated chitosan is a better substrate. Chitin, xylan, 6-O-sulphated chitosan and O-carboxymethyl chitin were indigestible by the purified enzyme. By endo-splitting activity, the chitosanase hydrolysed chitosan to form chitosan oligomers with chitotriose, chitotetraose and chitopentaose as the major products. The enzyme hydrolyses chitohexaose to form chitotriose, while the chitopentaose and shorter oligomers remain intact. The N-terminal amino acid sequence of the enzyme was determined as YNLPNNLKQIYDDHK, which provides useful information for further gene cloning of this enzyme. A 275 g-scale hydrolysis of chitosan was performed. The product distribution was virtually identical to that of the small-scale reaction. Owing to the simple purification process and high stability of the enzyme, it is potentially valuable for industrial applications. PMID:11115392

  15. Vestibular-evoked myogenic potentials in three patients with large vestibular aqueduct.

    PubMed

    Sheykholeslami, Kianoush; Schmerber, Sébastien; Habiby Kermany, Mohammad; Kaga, Kimitaka

    2004-04-01

    An enlarged vestibular aqueduct (LVA) is a common congenital inner ear anomaly responsible for some unusual vestibular and audiological symptoms. Most of the cases show bilateral early onset and progressive hearing loss in children. The gross appearance on CT scan of the inner ear is generally normal. However, precise measurements of the inner ear components reveal abnormal dimensions, which may account for the accompanying auditory and vestibular dysfunction. Despite extensive studies on hearing and the vestibular apparatus, saccular function is not studied. To our knowledge this is the first report of saccular malfunction in three patients with LVA by means of vestibular evoked myogenic potentials. Conventional audiograms revealed bilateral severe sensorineural hearing loss in two patients and mixed type hearing loss in one patient. Two of the patients complained about vertigo and dizziness but vestibular assessments of the patients showed normal results. The diagnosis had been made by high-resolution CT scans and MR images of the skull that showed LVA in the absence of other anomalies. The VEMP threshold measured from the ear with LVA in two patients with unilateral enlargement of the vestibular aqueduct was 75-80 dB nHL whereas the threshold from normal ears was 95 dB nHL. The third patient with mixed type hearing loss and bilateral LVA had VEMP responses despite a big air-bone gap in the low frequency range. The VEMP in this patient was greater in amplitude and lower in threshold in the operated ear (the patient had a tympanoplasty which did not improve her hearing). These findings and results of other patients with Tullio phenomenon and superior semicircular canal dehiscence, who also showed lower VEMP threshold, confirmed the theory of a 'third window' that allows volume and pressure displacements, and thus larger deflection of the vestibular sensors, which would cause the vestibular organ to be more responsive to sound and pressure changes. PMID:15051138

  16. Sex differences in autism spectrum disorder: evidence from a large sample of children and adolescents.

    PubMed

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

    2012-07-01

    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 ASD (mean verbal IQ = 92.6). There were no IQ sex differences. By parent report and direct observation, females had less repetitive stereotyped behaviour (RSB), with male-equivalent levels of social and communication impairment. Teachers reported males with ASD as having greater externalising and social problems than females. The female phenotype we describe was stable across our sample's age range. Their milder RSBs and less severe difficulties at school may lead to under-recognition of ASD in females. PMID:21947663

  17. [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

  18. Large-scale analysis of individual and task differences in search result page examination strategies

    Microsoft Academic Search

    Georg Buscher; Ryen W. White; Susan T. Dumais; Jeff Huang

    2012-01-01

    Understanding the impact of individual and task differences on search result page examination strategies is important in developing improved search engines. Characterizing these effects using query and click data alone is common but insufficient since they provide an incomplete picture of result examination behavior. Cursor- or gaze-tracking studies reveal richer interaction patterns but are often done in small-scale laboratory settings.

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

    Microsoft Academic Search

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

    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.

  20. Sensitivity tests on the criterion of potential vorticity index for discriminating the location of ozone sources and sinks over large continental areas

    NASA Astrophysics Data System (ADS)

    Cacòpardo, T.; Ferrarese, S.; Longhetto, A.; Cassardo, C.

    2004-03-01

    This paper presents the results of a sensitivity analysis of a statistical-dynamic model (ISOGASP, standing for Identification of SOurces of greenhouse GAS Plus), developed by our research group to reconstruct 3D concentration patterns of greenhouse gases in large and deep atmospheric regions over continental or oceanic areas and extending vertically from the lower troposphere to the lower stratosphere. The results of this analysis have shown the ability of the ISOGASP model to discriminate the locations of ozone sources, according to the geographical distribution patterns of atmospheric O3 concentration inside a limited number of atmospheric layers at different heights above sea level, reconstructed through the method of backward trajectories simulating the travel of air parcels from each different layer to the receptor points at their own height. The potential vorticity index has been used to discriminate the sub-sets of trajectories belonging to stratosphere or troposphere.

  1. Light baryon masses in different large-N{sub c} limits

    SciTech Connect

    Buisseret, Fabien; Semay, Claude [Service de Physique Nucleaire et Subnucleaire, Universite de Mons-UMONS, Academie universitaire Wallonie-Bruxelles, Place du Parc 20, B-7000 Mons (Belgium)

    2010-09-01

    We investigate the behavior of light baryon masses in three inequivalent large-N{sub c} limits: 't Hooft, QCD{sub AS} and Corrigan-Ramond. Our framework is a constituent quark model with relativistic-type kinetic energy, stringlike confinement, and one-gluon-exchange term, thus leading to well-defined results even for massless quarks. We analytically prove that the light baryon masses scale as N{sub c}, N{sub c}{sup 2}, and 1 in the 't Hooft, QCD{sub AS} and Corrigan-Ramond limits, respectively. Those results confirm previous ones obtained by using either diagrammatic methods or constituent approaches, mostly valid for heavy quarks.

  2. BWR containment flooding during a large break LOCA under different core damage conditions

    SciTech Connect

    Alammar, M.A.; Trikouros, N.G.; Hansen, P.N. [GPU Nuclear Corp., Parsippany, NJ (United States)

    1996-07-01

    The BWR Owners` Group require containment flooding as part of their Severe Accident Management Guidelines. It is shown in this analysis that flooding the containment increases the risk to containment integrity unless it is accompanied by a venting strategy. Using a large recirculation pipe break scenario with delayed core spray initiation such that 30% of the core had melted and relocated to the lower head (TMI-2 accident core damage) a venting strategy is formulated such that containment pressure is kept within Emergency Operating Procedures Limits. The strategy is based on the following criteria: (1) Venting starts when fission products scrubbing from the drywell atmosphere is completed; (2) Venting periods should be short to present water discharge through the vent due to level; (3) External injection may need to be terminated during venting to reduce interference with pressure behavior. The scenario was run until the drywell and the reactor pressure vessel were flooded above the top of active fuel elevation.

  3. 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.

  4. 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.

  5. Supplier involvement in automotive component design: are there really large US Japan differences?

    Microsoft Academic Search

    Jeffrey K. Liker; Rajan R. Kamath; S. Nazli Wasti; Mitsuo Nagamachi

    1996-01-01

    Typical descriptions of Japanese supplier management portray first-tier suppliers as partners in product development from the early concept stages of design, whereas US first-tier suppliers are provided detailed specifications and blueprints and build to print. This paper examines US\\/Japan differences in supplier involvement in design based on a 1993 survey of 143 Japanese and 189 US automotive component suppliers. The

  6. Floods can cause large interannual differences in littoral net ecosystem productivity

    Microsoft Academic Search

    Tuula Larmola; Jukka Alm; Sari Juutinen; Sanna Saarnio; Pertti J. Martikainen; Jouko Silvola

    2004-01-01

    Littoral wetlands comprise a terrestrial to aquatic continuum along which carbon dioxide is exchanged with the atmosphere and organic carbon is transferred to lakes. Net ecosystem productivity—the difference between atmo- spheric CO2 uptake and total ecosystem respiration—in these shore areas depends partly on the extent and duration of spring flooding. Ecosystem-atmosphere CO 2 fluxes were studied at a boreal lake

  7. 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 -180°C and 25°C. 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 -180°C. Such dramatic differences can drastically impact heat transfer during cryopreservation and their quantification is therefore critical to cryobiology. PMID:25985058

  8. 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.

  9. Low-frequency fatigue, post-tetanic potentiation and their interaction at different muscle lengths following eccentric exercise

    Microsoft Academic Search

    J. M. Rijkelijkhuizen; C. J. de Ruiter; P. A. Huijing; A. de Haan

    2005-01-01

    Low-frequency fatigue (LFF) and post-tetanic potentiation (PTP) were quantified at different muscle lengths in rat medial gastrocnemius (GM) muscle. In situ experiments were performed on GM muscle-tendon complexes of anaesthetised (urethane, 1.5·g·kg-1 i.p.) Wistar rats (N=8). Force-length characteristics were determined at maximal (200·Hz) and submaximal (60·Hz) stimulation. Data for submaximally stimulated muscle were obtained in a non-potentiated and in a

  10. Addressing impacts of different statistical downscaling methods on large scale hydrologic simulations

    NASA Astrophysics Data System (ADS)

    Mizukami, N.; Clark, M. P.; Gutmann, E. D.; Mendoza, P. A.; Brekke, L. D.; Arnold, J.; Raff, D. A.

    2013-12-01

    Many hydrologic assessments, such as evaluations of climate change impacts on water resources, require downscaled climate model outputs to force hydrologic simulations at a spatial resolution finer than the climate models' native scale. Statistical downscaling is an attractive alternative to dynamical downscaling methods for continental scale hydrologic applications because of its lower computational cost. The goal of this study is to illustrate and compare how the errors in precipitation and temperature produced by different statistical downscaling methods propagate into hydrologic simulations. Multi-decadal hydrologic simulations were performed with three process-based hydrologic models (CLM, VIC, and PRMS) forced by multiple climate datasets over the contiguous United States. The forcing datasets include climate data derived from gauge observations (M02) as well as climate data downscaled from the NCEP-NCAR reanalysis using 4 statistical downscaling methods for a domain with 12-km grid spacing: two forms of Bias Corrected Spatially Disaggregated methods (BCSD-monthly and BCSD-daily), Bias Corrected Constructed Analogue (BCCA), and Asynchronous Regression (AR). Our results show that both BCCA and BCSD-daily underestimate extreme precipitation events while AR produces these correctly at the scale at which the simulations were run but does not scale them up appropriately to larger basin scales like HUC-4 and HUC-2. These artifacts lead to a poor representation of flooding events when hydrologic models are forced by these methods over a range of spatial scales. We also illustrate that errors in precipitation depths dominate impacts on runoff depth estimations, and that errors in wet day frequency have a larger effect on shortwave radiation estimations than do the errors in temperatures; this error subsequently affects the partitioning of precipitation into evaporation and runoff as we show over mountainous areas of the upper Colorado River. Finally we show the inter-model differences across our simulations are generally lower than than inter-forcing data differences. We conclude with preliminary guidance on sound methodological choices for future climate impact studies using these methods. Comparison of annual precipitation between statistically downscaled data and observation (M02) and illustration of how these differences propagate into hydrologic simulations with two models. Figure shows the simulations over the western United States.

  11. Are large time differences in meteorite formation real. [cosmochronological dating and nucleosynthetic ratios

    NASA Technical Reports Server (NTRS)

    Cameron, A. G. W.

    1973-01-01

    Considerations are given concerning the interpretation of the results of two types of cosmochronological dating in order to examine the validity of the conclusions inferred from these results that the time intervals between the formation of various meteorite samples are very great. It is theorized that the isotopic differences between Angra dos Reis and other basaltic achondrites may be due to real fluctuations between the relative abundances of s-process and r-process nucleosynthesis products at a level delta about 0.001.

  12. Monitoring for potential adverse effects of prenatal gene therapy: use of large animal models with relevance to human application.

    PubMed

    Mehta, Vedanta; Abi-Nader, Khalil N; Carr, David; Wallace, Jacqueline; Coutelle, Charles; Waddington, Simon N; Peebles, Donald; David, Anna L

    2012-01-01

    Safety is an absolute prerequisite for introducing any new therapy, and the need to monitor the consequences of administration of both vector and transgene to the fetus is particularly important. The unique features of fetal development that make it an attractive target for gene therapy, such as its immature immune system and rapidly dividing populations of stem cells, also mean that small perturbations in pregnancy can have significant short- and long-term consequences. Certain features of the viral vectors used, the product of the delivered gene, and sometimes the invasive techniques necessary to deliver the construct to the fetus in utero have the potential to do harm. An important goal of prenatal gene therapy research is to develop clinically relevant techniques that could be applied to cure or ameliorate human disease in utero on large animal models such as sheep or nonhuman primates. Equally important is the use of these models to monitor for potential adverse effects of such interventions. These large animal models provide good representation of individual patient-based investigations. However, analyses that require defined genetic backgrounds, high throughput, defined variability and statistical analyses, e.g. for initial studies on teratogenic and oncogenic effects, are best performed on larger groups of small animals, in particular mice. This chapter gives an overview of the potential adverse effects in relation to prenatal gene therapy and describes the techniques that can be used experimentally in a large animal model to monitor the potential adverse consequences of prenatal gene therapy, with relevance to clinical application. The sheep model is particularly useful to allow serial monitoring of fetal growth and well-being after delivery of prenatal gene therapy. It is also amenable to serially sampling using minimally invasive and clinically relevant techniques such as ultrasound-guided blood sampling. For more invasive long-term monitoring, we describe telemetric techniques to measure the haemodynamics of the mother or fetus, for example, that interferes minimally with normal animal behaviour. Implanted catheters can also be used for serial fetal blood sampling during gestation. Finally, we describe methods to monitor events around birth and long-term neonatal follow-up that are important when considering human translation of this therapy. PMID:22648778

  13. Forcing the statistical regionalization method WETTREG with large scale models of different resolution: A sensitivity study

    NASA Astrophysics Data System (ADS)

    Spekat, A.; Baumgart, S.; Kreienkamp, F.; Enke, W.

    2010-09-01

    The statistical regionalization method WETTREG is making use of the assumption that future climate changes are linked to changes in large scale atmospheric patterns. The frequency distributions of those patterns and their time-dependency are identified in the output fields of dynamical climate models and applied to force WETTREG. Thus, the magnitude and the time evolution of high-resolution climate signals for time horizons far into the 21st century can be computed. The model results employed to force WETTREG include the GCMS ECHAM5C, HadCM3C and CNRM. Additionally results from the dynamical regional models CLM, DMI, HadRM, RACMO and REMO, nested into one or more of these global models, are used in their pattern-generating capacity to force WETTREG. The study yield insight concerning the forcing-dependent sensitivity of WETTREG as well as the bandwidth of climate change signals. Recent results for the German State of Hesse will be presented in an intercomparison study.

  14. Analysis of different intraseasonal patterns of large-scale circulation over the Amazon

    NASA Astrophysics Data System (ADS)

    de Oliveira, C. P.; Ambrizzi, T.; Aimola, L. D.

    2014-12-01

    It is well known that the large-scale equatorial circulation known as the Madden-Julian Oscillation (MJO) has an important impact on the convective activity over South America. The Bolivian high is an upper-level (200 hPa) anticyclone that develops during the summer over the Bolivian Altiplano, a high plateau region of the Central Andes. The position and intensity of this high-pressure cell has been related to the seasonal variation in Amazonian rainfall. This study used the Real-time Multivariate MJO index created by Wheeler and Hendon to examine the impacts and intensification of Bolivian high using daily rainfall data from Tropical Rainfall Measuring Mission (TRMM) and 6-hourly atmospheric fields from the ECMWF Interim reanalysis (ERA Interim). Enhance of precipitation filtered for 20-100-day during 3 to 6 MJO phase is accompanied by a significant suppression of high level zonal winds near northern South Atlantic coast and vice versa, i.e., suppressed precipitation for the same filtered data is associated with an enhancement of the wind near South Atlantic coast, for 8 to 1 phase. Intensification and positioning slightly more southwest of the Bolivian high was observed when there was an increase in convection associated with MJO. This convection enhancement increases the magnitude of the divergence at high levels that consequently favored convection.

  15. 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

  16. Is splash erosion potential species specific? Measuring of splash erosion potential under forest in different succession stages along a biodiversity gradient in the humid subtropics

    NASA Astrophysics Data System (ADS)

    Geißler, C.; Kühn, P.; Scholten, T.

    2009-04-01

    It is widely accepted that (forest) vegetation is a key control for the type and intensity of soil erosion. The current paradigm is that natural or quasi-natural vegetation protects the soil from erosion and that agricultural vegetation or land use generally enhances erosion. The latter was in focus of most research during the last decades and less interest was paid on natural systems, which are more difficult to study. Nevertheless, afforestation is widely used as a measure of soil protection against soil erosion. Rainfall can be highly erosive particularly in the humid subtropics. Regarding climate change, also precipitation regime may change in direction to even more severe storms and higher rainfall intensities; it is a research field of growing importance. Key mechanisms of a vegetation cover in reducing or enhancing erosion are modifications of drop-size distribution, retention of raindrop impact on the soil and changes in amount and spatial distribution of rainfall at the ground surface. Controlling determinants are rainfall intensity, drop size distribution, drop fall velocity, height of the canopy as well as density of the canopy, crown and leaf traits, LAI and coverage by a litter layer. Large drops are supposed to be significant sources of splash detachment in forests (Brandt 1989; Vis 1986). However, the mechanisms of reducing (or enhancing?) splash detachment under forest in relation to species richness and species composition are not well understood. Some studies indicate that raindrop impact is species specific (Calder 2001; Nanko et al. 2006) and some neglect the effects of species specific impacts (Foot & Morgan 2005). Our research uses different methods of rainfall characterization (splash cups, tipping-bucket rain gauge, laser distrometer) to reveal the described mechanisms from the canopy through different vegetation layers to the ground. First results of splash cup measurements (revised after Ellison 1947) show that sand loss under vegetation is 2.5 times higher than in open field despite the fact that only 60 percent of open field rainfall reaches the ground. The results also indicate that sand loss is a function of the age of the specific forest stand and the variability of sand loss under different species with respect to space and time. These and future results will help managing afforestation projects in giving implications which of the species (resp. species compositions) may reduce most effectively potential splash erosion. References: Brandt, C. J. (1989): The size distribution of throughfall drops under vegetation canopies. Catena 16, p. 507-524. Calder, I. R. (2001): Canopy processes: implications for transpiration, interception and splash induced erosion, ultimately for forest management and water resources. Plant Ecology 153, p. 203-214. Ellison, W. D. (1947): Soil Erosion Studies - Part II. Soil Detachment Hazard by Raindrop Splash. Agricultural Engineering 28, p. 197-201. Foot, K.; Morgan, R. P. C. (2005): The role of leaf inclination, leaf orientation and plant canopy architecture in soil particle detachment by raindrops. Earth Surface Processes and Landforms 30, p. 1509-1520. Nanko, K.; Hotta, N. & Suzuki, M. (2006): Evaluating the influence of canopy species and meteorological factors on throughfall drop size distribution. Journal of Hydrology 329, p. 422-431. Vis, M. (1986): Interception, drop size distributions and rainfall kinetic energy in four colombian forest ecosystems. Earth Surface Processes and Landforms 11, p. 591-603.

  17. 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

  18. 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 (NO?-N) and Total Phosphorus (TP) loads were slightly affected by the DEM resolution; and (v) flow and Ammonia Nitrogen (NH?-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 NO?-N was 30-300 m, for NH?-N was 30 to 70 m and for TN was 30-150 m. PMID:24509347

  19. 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.

  20. The measurement of large optical frequency differences and the design of a new type of frequency chain

    Microsoft Academic Search

    Thomas Udem; Jorg Reichert; Ronald Holzwarth; Theodor Hansch; Motonobu Kourogi

    1999-01-01

    We have used optical frequency interval dividers, optical frequency comb generators and mode-locked lasers to measure large optical frequency differences of up to 45.2 THz between laser frequencies. We have shown that the modes of a mode-locked laser are distributed uniformly in frequency space within the experimental limit of 3.0 parts in 1017 and that the mode separation equals the

  1. 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...

  2. 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,…

  3. From a different perspective: principles, practice and potential of bistatic radar

    Microsoft Academic Search

    H. D. Griffiths

    2003-01-01

    Bistatic radar systems have been studied and built since the earliest days of radar. They have the advantages that the receivers are passive, and hence undetectable. The receiving systems are also potentially simple and cheap. Bistatic radar may have a counter-stealth capability, since target shaping to reduce monostatic RCS will in general not reduce the bistatic RCS. In spite of

  4. A model for viscosity coefficients of gases with potentials differing in form

    Microsoft Academic Search

    Fernando Del Río; Benjamín Ibarra; Luis Mier Y. Terán

    2003-01-01

    A recent theory of non-conformal interactions has been very succesful in providing effective spherical potentials for the pressure of more than 40 real gases and many of their binary mixtures. Here, this theory is applied to deal with low-density viscosity coefficients. In its simplest form, the approximate non-conformal (ANC) theory introduces, besides the usual corresponding states parameters - energy ?

  5. Phorbol Esters Potentiate Evoked and Spontaneous Release by Different Presynaptic Mechanisms

    Microsoft Academic Search

    Jack Waters; Stephen J Smith

    2000-01-01

    Phorbol esters enhance release from a variety of cell types. The mechanism by which phorbol esters potentiate presynaptic re- lease from central neurons is unclear, although effects of phorbol esters both on the readily releasable pool of vesicles and on presynaptic calcium channels have been shown. Using confocal microscopy and the fluorescent styryl dye FM 1-43, we have examined the

  6. Association of schizotypy with semantic processing differences: An event-related brain potential study

    E-print Network

    Kutas, Marta

    -related brain potential (ERP) elicited during a category-verification task. ERPs were recorded in young adults Abstract Disorganized speech in both schizophrenia and schizotypy has been hypothesized to result from in schizophrenia has been hypothesized to result from abnormalities in how words, and the concepts they represent

  7. Human brain potentials to reading syntactic errors in sentences of different complexity

    Microsoft Academic Search

    Thomas F. Münte; Andras Szentkuti; Bernardina M. Wieringa; Mike Matzke; Sönke Johannes

    1997-01-01

    In order to determine if an event-related brain potential (ERP) effect described for syntactic violations (P600\\/SPS) varies with the amount of reprocessing entailed by a violation, number incongruencies were presented either within simple declarative or within subordinate clauses. ERPs were recorded while 12 German subjects read the stimulus materials presented word by word on a video monitor. The ERPs showed

  8. Systematic evaluation of the antioxidant potential of different parts of Foeniculum vulgare Mill. from Portugal

    Microsoft Academic Search

    Lillian Barros; Sandrina A. Heleno; Ana Maria Carvalho; Isabel C. F. R. Ferreira

    2009-01-01

    Fennel (Foeniculum vulgare Mill.) is a widespread perennial umbeliferous (Apiaceae) herb, traditionally used for medicinal purposes and human consumption. It is highly recommended for diabetes, bronchitis and chronic coughs, and for the treatment of kidney stones; some of those chronic diseases are related to the production of radical species involved in the oxidative stress. Therefore, the antioxidant potential of this

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

    SciTech Connect

    Bevelhimer, Mark S [ORNL; Giffen, Neil R [ORNL; Stevenson, Dirk [Ft Stewart Fish and Wildlife Branch

    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).

  10. Channel formation during flushing of large shallow reservoirs with different geometries.

    PubMed

    Kantoush, Sameh A; Schleiss, Anton J

    2009-07-01

    Depositional and flow patterns are first described to gain an understanding of the erosion patterns during hydraulic flushing in a reservoir. Considering the importance of this issue, two modes of flushing operation for control of sedimentation were performed in several experiments with different reservoir geometries. In order to investigate the effect of flushing and the effectiveness during free and drawdown flows, ten experiments have been conducted. The final bed morphology formed previously was used as the initial bed topography for the two modes of flushing. The entire experiments lasted for two days. Investigations of the flow pattern and the associated bed topography for free flow with normal water depth and drawdown flushing in various shallow reservoir geometries are presented. To effectively apply the flushing processes for the removal of sediment deposits, the location, depth and width of the flushing channel can be changed by modifications to the reservoir geometry. The channel formed during flushing attracts the jet and stabilizes the flow structures over the entire surface. Empirical formulae to describe the relationship between the reservoir geometry and flushing efficiency for the two modes of flushing were developed. Flushing at normal water level allows only a relatively small part of the deposited sediment to be evacuated. As deposits could be flushed out of the basin. PMID:19705670

  11. Overexpression of the Large-Conductance, Ca2+-Activated K+ (BK) Channel Shortens Action Potential Duration in HL-1 Cardiomyocytes

    PubMed Central

    Stimers, Joseph R.; Song, Li; Rusch, Nancy J.; Rhee, Sung W.

    2015-01-01

    Long QT syndrome is characterized by a prolongation of the interval between the Q wave and the T wave on the electrocardiogram. This abnormality reflects a prolongation of the ventricular action potential caused by a number of genetic mutations or a variety of drugs. Since effective treatments are unavailable, we explored the possibility of using cardiac expression of the large-conductance, Ca2+-activated K+ (BK) channel to shorten action potential duration (APD). We hypothesized that expression of the pore-forming ? subunit of human BK channels (hBK?) in HL-1 cells would shorten action potential duration in this mouse atrial cell line. Expression of hBK? had minimal effects on expression levels of other ion channels with the exception of a small but significant reduction in Kv11.1. Patch-clamped hBK? expressing HL-1 cells exhibited an outward voltage- and Ca2+-sensitive K+ current, which was inhibited by the BK channel blocker iberiotoxin (100 nM). This BK current phenotype was not detected in untransfected HL-1 cells or in HL-1 null cells sham-transfected with an empty vector. Importantly, APD in hBK?-expressing HL-1 cells averaged 14.3 ± 2.8 ms (n = 10), which represented a 53% reduction in APD compared to HL-1 null cells lacking BK? expression. APD in the latter cells averaged 31.0 ± 5.1 ms (n = 13). The shortened APD in hBK?-expressing cells was restored to normal duration by 100 nM iberiotoxin, suggesting that a repolarizing K+ current attributed to BK channels accounted for action potential shortening. These findings provide initial proof-of-concept that the introduction of hBK? channels into a cardiac cell line can shorten APD, and raise the possibility that gene-based interventions to increase hBK? channels in cardiac cells may hold promise as a therapeutic strategy for long QT syndrome. PMID:26091273

  12. Resting potential and electrical properties of frog slow muscle fibres. Effect of different external solutions

    PubMed Central

    Stefani, E.; Steinbach, A. B.

    1969-01-01

    1. The electrical properties of frog slow muscle fibres were investigated with intracellular micropipettes to determine their characteristic length (?), specific membrane resistance (Rm) and specific membrane capacitance. 2. The value of ? was about 1 cm in fibres of 1·2 cm length. The `short cable model' was used to calculate Rm. Its mean value was 1·12 × 105 ohm cm2, about 10-20 times larger than the value for twitch fibres. The mean value for Cm was 3·24 × 10-6 F/cm2. 3. Resting potentials measured immediately after penetration with a single micropipette were about — 80 mV. Lower values can be attributed to the effects of damage or leakage produced by micropipette insertion. 4. Changes in external K concentration produced changes in the initially recorded resting potentials which follow the constant field theory using a ratio of Na: K permeabilities PNa/PK = 0·02. Changes in external Cl concentration produced little or no change in the resting potential or membrane resistance, indicating a low Cl permeability. 5. In agreement with previous work, slow fibres showed a time-dependent decrease in resistance (`delayed rectification') for membrane potentials more positive than — 60 mV. `Anomalous rectification' observed in twitch fibres was not seen in slow fibres. In high external K concentrations the resistance of slow fibres is almost unaffected by changes in membrane potential. 6. Increasing the concentration of external Ca (up to isotonic) has two distinct effects on slow fibres. It increases Rm up to ten times, and it improves the stability of trans-membrane recordings, probably by reducing the leakage due to micropipette penetrations. Magnesium does not appear to have either of these effects. PMID:5796469

  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. 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 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 Hövsgöl, 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 Hövsgöl 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 Hövsgöl 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 Hövsgöl 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 Hövsgöl 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

  15. M-wave potentiation after voluntary contractions of different durations and intensities in the tibialis anterior.

    PubMed

    Rodriguez-Falces, Javier; Duchateau, Jacques; Muraoka, Yoshiho; Baudry, Stéphane

    2015-04-15

    The study was undertaken to provide insight into the mechanisms underlying the potentiation of the muscle compound action potential (M wave) after conditioning contractions. M waves were evoked in the tibialis anterior before and after isometric maximal voluntary contractions (MVC) of 1, 3, 6, 10, 30, and 60 s, and after 3-s contractions at 10, 30, 50, 70, 90, and 100% MVC. The amplitude, duration, and area of the first and second phases of the M wave, together with the median frequency (Fmedian) and muscle fiber conduction velocity (MFCV) were recorded. Furthermore, twitch force, muscle fascicle length, and pennation angle were measured at rest, before, and 1 s after the conditioning contractions. The results indicate that only the amplitude of the second phase of the M wave was significantly increased after conditioning contractions. The extent of this potentiation was similar for MVC durations ranging from 1 to 10 s and augmented progressively with contraction intensity from 30 to 70% MVC. After these conditioning contractions, the duration and area of the two M-wave phases decreased (P < 0.05), whereas MFCV and Fmedian increased (P < 0.05). For all of these parameters, the greatest changes occurred 1 s after the conditioning contraction. Changes in MFCV after the contractions were correlated with those in M-wave second-phase amplitude (r(2) = 0.42; P < 0.05) and Fmedian (r(2) = 0.53; P < 0.05). In contrast, fascicle length and pennation angle did not change after the conditioning contractions. It is concluded that the potentiation of the second phase of the M wave is mainly due to an increased MFCV. PMID:25678703

  16. A model for viscosity coefficients of gases with potentials differing in form

    Microsoft Academic Search

    FERNANDO DEL RÍO; BENJAMÍN IBARRA; LUIS MIER Y TERÁN

    2003-01-01

    A recent theory of non-conformal interactions has been very succesful in providing effective spherical potentials for the pressure of more than 40 real gases and many of their binary mixtures. Here, this theory is applied to deal with low-density viscosity coefficients. In its simplest form, the approximate non-conformal (ANC) theory introduces, besides the usual corresponding states parameters-energy ? and distance

  17. Potential errors in the volume of distribution estimation of therapeutic proteins composed of differently cleared components

    Microsoft Academic Search

    Wolfgang F. Richter; Hans Peter Grimm; Frank-Peter Theil

    The volume of distribution at steady state (Vss) of therapeutic proteins is usually assessed by non-compartmental or compartmental pharmacokinetic (PK) analysis wherein\\u000a errors may arise due to the elimination of therapeutic proteins from peripheral tissues that are not in rapid equilibrium\\u000a with the sampling compartment (usually blood). Here we explored another potential source of error in the estimation of Vss

  18. How Cytochromes with Different Folds Control Heme Redox Potentials Junjun Mao, Karin Hauser, and M. R. Gunner*

    E-print Network

    Gunner, Marilyn

    ) the energy to change a pKa by 1 pH unit at 25 °C. © Copyright 2003 by the American Chemical Society Volume 42Articles How Cytochromes with Different Folds Control Heme Redox Potentials Junjun Mao, Karin Hauser, and M. R. Gunner* Physics Department J-419, City College of New York, 138th Street and Con

  19. Bacterial genome adaptation to niches: Divergence of the potential virulence genes in three Burkholderia species of different survival strategies

    Microsoft Academic Search

    H Stanley Kim; Mark A Schell; Yan Yu; Ricky L Ulrich; Saul H Sarria; William C Nierman; David DeShazer

    2005-01-01

    BACKGROUND: Two closely related species Burkholderia mallei (Bm) and Burkholderia pseudomallei (Bp) are serious human health hazards and are potential bio-warfare agents, whereas another closely related species Burkholderia thailandensis (Bt) is a non-pathogenic saprophyte. To investigate the genomic factors resulting in such a dramatic difference, we first identified the Bm genes responsive to the mouse environment, and then examined the

  20. Differences in the way potassium chloride and sucrose solutions effect osmotic potential of significance to stomata aperture modulation

    Microsoft Academic Search

    Thomas T. Cochrane; Thomas A. Cochrane

    2009-01-01

    Guard cell solution osmotic potential changes resulting in the opening and closing of stomata apertures follow an initial influx of potassium ions, their substitution with sucrose molecules and the subsequent reduction of the latter. To provide an insight into the osmotic mechanism of the changes, the new equation for calculating osmotic pressure, which equates the difference between the energy of

  1. 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

  2. Finite-Difference Time-Domain Numerical Analysis of Elastic Wave Fields Using both Elastic and Velocity Potential Variables

    NASA Astrophysics Data System (ADS)

    Sato, Masahiro

    2006-05-01

    The use of both elastic variables and velocity potentials is proposed for the analysis of elastic wave fields in isotropic solids by finite-difference time-domain (FDTD) methods. The term ‘elastic variables’ refers to stresses and particle velocities. Velocity potentials can be directly derived using the same leap-frog finite-difference scheme as in the FDTD method. In some situations, for example, where an absorbing boundary is present, it is more straightforward to calculate using velocity potentials. This approach also provides an easy way to handle of complex elastic wave phenomena. On the other hand, many other types of boundary conditions are often expressed in terms of elastic variables. In these situations, it is more convenient to use elastic variables for calculation. Some examples are introduced here to illustrate the efficiency of the proposed technique. First, the method was used for the case of an absorbing boundary. In the model, almost all analysis was carried out using values of stress and particle velocity, but velocity potentials were applied near the absorbing boundary on the truncated interface. Second, an interface between elastic variables and velocity potentials, namely a stress-velocity/potentials interface, was constructed around a scattering object. External to the interface, stresses and particle velocities were used for calculation, and potential variables were applied inside the interface. In a third example, calculations were made over almost the entire analytical region using potential values, but in the neighborhood of the free boundary, elastic variables were used. All the examples above were analyzed numerically using the FDTD method, and the results confirmed the usefulness of the method.

  3. Potential for large-scale submarine slope failure and tsunami generation along the U.S. mid-Atlantic coast

    NASA Astrophysics Data System (ADS)

    Driscoll, Neal W.; Weissel, Jeffrey K.; Goff, John A.

    2000-05-01

    The outer continental shelf off southern Virginia and North Carolina might be in the initial stages of large-scale slope failure. A system of en echelon cracks, resembling small-offset normal faults, has been discovered along the outer shelf edge. Swath bathymetric data indicate that about 50 m of down-to-the-east (basinward) normal slip has occurred on these features. From a societal perspective, we need to evaluate the degree of tsunami hazard that might be posed by a major submarine landslide, such as the nearby late Pleistocene Albemarle-Currituck slide, if it nucleated on the newly discovered crack system. Toward this goal, a tsunami scenario is constructed for the nearby coastal zone based on the estimated volume and nature of the potential slide. Although a maximum tsunami height of a few to several meters is predicted, the actual extent of flooding would depend on the tidal state at the time of tsunami arrival as well as the details of the hinterland topography. The Virginia North Carolina coastline and lower Chesapeake Bay would be most at risk, being nearby, low lying, and in a direction opposite to potential slide motion.

  4. Review of NO{sub x} control technologies potentially feasible for installation on large utility boilers in Maryland

    SciTech Connect

    Ross, J.; DiPrinzio, M.; Walls, G.

    1999-07-12

    Under its NO{sub x} Budget regulations (COMAR 26.11.27 and 26.11.28), the Maryland Department of the Environment (MDE) must ensure that the State obtained a 65% reduction in nitrogen oxides (NO{sub x}) emissions from target sources during the ozone season (May-October) relative to 1990 baseline NO{sub x} emissions. MDE is proposing to revise its NO{sub x} Budget regulations to delay the target compliance date for affected sources from 1 May 1999 to 1 May 2000. In this study, the Maryland Power Plant Research Program (PPRP) evaluated feasible options to control NO{sub x} emissions from large utility boilers in Maryland. The primary goal of this assessment was to provide as much plant- and unit-specific information as possible on NO{sub x} control technology alternatives for large utility boilers in operation in Maryland. Potential NO{sub x} control systems considered in this assessment included primary controls, such as low-NO{sub x} burners, overfire air, and other combustion modifications; and secondary controls, including selective catalytic reduction, selective non-catalytic reduction, reburning (gas and coal reburn), and hybrid systems.

  5. 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.

  6. Distinct Stem Cells Subpopulations Isolated from Human Adipose Tissue Exhibit Different Chondrogenic and Osteogenic Differentiation Potential

    Microsoft Academic Search

    Tommaso Rada; Rui L. Reis; Manuela E. Gomes

    2011-01-01

    Recently adipose tissue has become a research topic also for the\\u000d\\u000a searching for an alternative stem cells source to use in cell based\\u000d\\u000a therapies such as tissue engineer. In fact Adipose Stem Cells (ASCs)\\u000d\\u000a exhibit an important differentiation potential for several cell lineages\\u000d\\u000a such as chondrogenic, osteogenic, myogenic, adipogenic and endothelial\\u000d\\u000a cells. ASCs populations isolated using standard methodologies (i.e.,\\u000d\\u000a based

  7. A large prospective study of meat consumption and colorectal cancer risk: an investigation of potential mechanisms underlying this association

    PubMed Central

    Cross, Amanda J.; Ferrucci, Leah M.; Risch, Adam; Graubard, Barry I .; Ward, Mary H.; Park, Yikyung; Hollenbeck, Albert R.; Schatzkin, Arthur; Sinha, Rashmi

    2010-01-01

    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 (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) intake 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 MeIQx and HR=1.17, 95% CI: 1.05-1.29; p-trend <0.001 for 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

  8. 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

  9. Potential population growth and harmful effects on humans from bed bug populations exposed to different feeding regimes.

    PubMed

    Pereira, R M; Taylor, A S; Lehnert, M P; Koehler, P G

    2013-06-01

    Effects of host availability and feeding period on bed bugs, Cimex lectularius (L.) (Hemiptera: Cimicidae), were measured. Population growth and the potential harmful effect of bed bug populations on human hosts were modelled. Bloodmeal sizes were affected by both feeding length and frequency, with >2-fold difference between insects fed daily or weekly. Blood consumption increased >2-fold between bed bugs fed occasionally and often, and 1.5-fold between occasional and daily feeding. Bed bugs fed more often than once a week, potentially every 2-4 days. Egg production was associated with nutrition, being strongly correlated with blood consumption in the previous week. Bed bug populations can grow under different feeding regimes and are hard to control with <80% mortality. Bed bugs can survive and grow even in locations with a limited blood supply, where bed bug persistence may be important for the continual spread of populations. Persistence in non-traditional locations and a potential association with human pathogens increase the health risks of bed bugs. Potential blood loss as a result of a bed bug can have serious consequences because uncontrolled populations can reach harmful levels in 3-8 months. The reproduction potential of bed bug populations suggests serious consequences to human health and the need for efficacious control measures. PMID:23046478

  10. [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

  11. Mitigating the Goldilocks effect: the effects of different substrate models on track formation potential.

    PubMed

    Falkingham, Peter L; Hage, Julian; Bäker, Martin

    2014-11-01

    In ichnology, the Goldilocks effect describes a scenario in which a substrate must be 'just right' in order for tracks to form-too 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 elastic-perfectly 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

  12. Mitigating the Goldilocks effect: the effects of different substrate models on track formation potential

    PubMed Central

    Falkingham, Peter L.; Hage, Julian; Bäker, 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 form—too 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 elastic–perfectly 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.

  13. Contrasting nutrient mitigation and denitrification potential of agricultural drainage environments with different emergent aquatic macrophytes.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 period...

  14. Hemispheric Differences in Strong versus Weak Semantic Priming: Evidence from Event-Related Brain Potentials

    ERIC Educational Resources Information Center

    Frishkoff, Gwen A.

    2007-01-01

    Goals: Research with lateralized word presentation has suggested that strong ("close") and weak ("remote") semantic associates are processed differently in the left and right cerebral hemispheres [e.g., Beeman, M. j., & Chiarello, C. (1998). Complementary right- and left-hemisphere language comprehension. "Current Directions in Psychological…

  15. Isolation and characterization of different plant associated bacteria and their potential to degrade polychlorinated biphenyls

    Microsoft Academic Search

    Marieta Ionescu; Katarina Beranova; Vlasta Dudkova; Lucie Kochankova; Katerina Demnerova; Tomas Macek; Martina Mackova

    2009-01-01

    In our experiments the effect of different plants on microbial activities resulting in degradation and PCB removal from long-term contaminated soil was evaluated. Total bacteria and bacteria representing the dominating microflora within rhizosphere of individual plant species – tobacco (Nicotiana tabacum), black nightshade (Solanum nigrum), horseradish (Armoracia rusticana) and goat willow (Salix caprea) planted in PCB contaminated soil as well

  16. A Risky Business: The Potential of Groupwork Skills for Spiritual Education in a Classroom of Difference

    ERIC Educational Resources Information Center

    Ota, Cathy

    2006-01-01

    This article considers the notion of difference as we experience it in our daily lives, and specifically, within the classroom between pupils and teachers. Drawing on research and work with schools in the south of England, the paper describes how the Working with Others Unit at the University of Brighton has developed a practical process approach…

  17. Difference-Sensitive Communities, Networked Learning, and Higher Education: Potentialities and Risks

    ERIC Educational Resources Information Center

    Papastephanou, Marianna

    2005-01-01

    Recent emphases on prospects for difference-sensitive virtual communities rely implicity or explicity on some optimist accounts of cyberspace and globalization. It is expected that hybridity, diaspora and fluidity, marking new understandings of spatiality and temporality in a globalized postmodern era, will create new forms of belonging that will…

  18. Potential of different composts to improve soil fertility and plant health

    Microsoft Academic Search

    JACQUES G. FUCHS; URS BAIER; ALFRED BERNER; JOCHEN MAYER; LUCIUS TAMM; KONRAD SCHLEISS

    2006-01-01

    soil fertility and plant health positively, we analyzed one hundred composts representative of the different composting systems and qualities available on the market. The organic substance and the nutrient content of the composts varied greatly between the composts; the materials of origin were the major factor influencing these values. The respiration rate and enzyme activities also varied greatly, particularly in

  19. 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

  20. Global accuracy estimates of point and mean undulation differences obtained from gravity disturbances, gravity anomalies and potential coefficients

    NASA Technical Reports Server (NTRS)

    Jekeli, C.

    1979-01-01

    Through the method of truncation functions, the oceanic geoid undulation is divided into two constituents: an inner zone contribution expressed as an integral of surface gravity disturbances over a spherical cap; and an outer zone contribution derived from a finite set of potential harmonic coefficients. Global, average error estimates are formulated for undulation differences, thereby providing accuracies for a relative geoid. The error analysis focuses on the outer zone contribution for which the potential coefficient errors are modeled. The method of computing undulations based on gravity disturbance data for the inner zone is compared to the similar, conventional method which presupposes gravity anomaly data within this zone.

  1. Accumulation of thallous ions (Tl+) as a measure of the electrical potential difference across the cytoplasmic membrane of bacteria.

    PubMed

    Bakker, E P

    1978-07-11

    The accumulation of thallous ions (204Tl+) by intact bacteria was investigated. I conclude that Tl+ is a permeant cation, and that it therefore accumulates in response to the electrical potential difference (delta psi) across the cytoplasmic membrane (interior negative). A comparison with other methods shows that the distribution ratio of 204Tl+ serves as a reasonably satisfactory method for measuring the membrane potential of Streptococcus faecalis. Glycolyzing cells of this organism develop membrane potentials of up to 180 mV. Preliminary experiments with Escherichia coli, especially those with a mutant defective in the proton-translocating ATPase, indicate that the Tl+ distribution also serves as a measure of the membrane potential in this organism. The particular advantage of Tl+ over other indicators of the membrane potential is that the cells need not be pretreated in any way. By use of the Tl+ distribution, it was calculated that respiring cells of E. coli develop a membrane potential of 160 mV with D-lactate and 180 mV with glucose as a substrate, respectively. PMID:99163

  2. [Visual evoked potentials and functional asymmetry in children with with different degrees of intellectual retardation].

    PubMed

    Katargina, T A; Kryzhanovskaia, I L; Petrova, M A

    1993-01-01

    Visual evoked potentials (VEP) to flash and patterned visual stimuli have been recorded from occipital and central brain regions in 7-8-year-old boys with normal intellect (20 cases), with mental retardation (15 cases) and with oligophrenia of a debile degree (27 cases). A significant elongation of late-component latency has been revealed in motor brain areas VEP in oligophrenia group compared to normal subjects. A negative correlation between P190 component latency of motor area VEP to patterned visual stimulus and general and non-verbal intellectual indices has been stated in full right-handed subjects with intellectual deficiency. Such a relation was absent in right-handed patients with left dominant eye. PMID:8042397

  3. Bladder substitutes controlled by the anal sphincter: A comparison of the different absorption potentials

    SciTech Connect

    el-Mekresh, M.M.; Shehab el-Din, A.B.; Fayed, S.M.; Brevinge, H.; Kock, N.G.; Ghoneim, M.A. (Department of Urology, Urology-Nephrology Center, Mansoura (Egypt))

    1991-10-01

    A comparative study of the absorption potentials of the simple rectal bladder (10 patients), modified rectal bladder (20) and ureterosigmoidostomy (10) was done with intrarectal instillation of 22sodium. Results indicate that absorption is significantly greater among patients with ureterosigmoidostomy. The emptying patterns of ureterosigmoidostomy and the modified rectal bladder were also studied by ascending scintigraphy with 99mtechnetium. Evidence was provided that in cases with ureterosigmoidostomy the isotope is distributed throughout the entire colon. These studies proved the role of the colorectal valve in preventing reflux of urine from the rectum to the proximal colon. Consequently, the surface area of colonic mucosa exposed to urine is decreased and the rate of reabsorption is limited.

  4. Identification of Different Types of Spinal Afferent Nerve Endings That Encode Noxious and Innocuous Stimuli in the Large Intestine Using a Novel Anterograde Tracing Technique

    PubMed Central

    Spencer, Nick J.; Kyloh, Melinda; Duffield, Michael

    2014-01-01

    In mammals, sensory stimuli in visceral organs, including those that underlie pain perception, are detected by spinal afferent neurons, whose cell bodies lie in dorsal root ganglia (DRG). One of the major challenges in visceral organs has been how to identify the different types of nerve endings of spinal afferents that transduce sensory stimuli into action potentials. The reason why spinal afferent nerve endings have been so challenging to identify is because no techniques have been available, until now, that can selectively label only spinal afferents, in high resolution. We have utilized an anterograde tracing technique, recently developed in our laboratory, which facilitates selective labeling of only spinal afferent axons and their nerve endings in visceral organs. Mice were anesthetized, lumbosacral DRGs surgically exposed, then injected with dextran-amine. Seven days post-surgery, the large intestine was removed. The characteristics of thirteen types of spinal afferent nerve endings were identified in detail. The greatest proportion of nerve endings was in submucosa (32%), circular muscle (25%) and myenteric ganglia (22%). Two morphologically distinct classes innervated myenteric ganglia. These were most commonly a novel class of intraganglionic varicose endings (IGVEs) and occasionally rectal intraganglionic laminar endings (rIGLEs). Three distinct classes of varicose nerve endings were found to innervate the submucosa and circular muscle, while one class innervated internodal strands, blood vessels, crypts of lieberkuhn, the mucosa and the longitudinal muscle. Distinct populations of sensory endings were CGRP-positive. We present the first complete characterization of the different types of spinal afferent nerve endings in a mammalian visceral organ. The findings reveal an unexpectedly complex array of different types of primary afferent endings that innervate specific layers of the large intestine. Some of the novel classes of nerve endings identified must underlie the transduction of noxious and/or innocuous stimuli from the large intestine. PMID:25383884

  5. Potential yields and properties of oil from the hydrothermal liquefaction of microalgae with different biochemical content.

    PubMed

    Biller, P; Ross, A B

    2011-01-01

    A range of model biochemical components, microalgae and cyanobacteria with different biochemical contents have been liquefied under hydrothermal conditions at 350 °C, ?200 bar in water, 1M Na(2)CO(3) and 1M formic acid. The model compounds include albumin and a soya protein, starch and glucose, the triglyceride from sunflower oil and two amino acids. Microalgae include Chlorella vulgaris,Nannochloropsis occulata and Porphyridium cruentum and the cyanobacteria Spirulina. The yields and product distribution obtained for each model compound have been used to predict the behaviour of microalgae with different biochemical composition and have been validated using microalgae and cyanobacteria. Broad agreement is reached between predictive yields and actual yields for the microalgae based on their biochemical composition. The yields of bio-crude are 5-25 wt.% higher than the lipid content of the algae depending upon biochemical composition. The yields of bio-crude follow the trend lipids>proteins>carbohydrates. PMID:20599375

  6. Major Structural Differences and Novel Potential Virulence Mechanisms from the Genomes of Multiple Campylobacter Species

    Microsoft Academic Search

    Derrick E. Fouts; Emmanuel F. Mongodin; Robert E. Mandrell; William G. Miller; David A. Rasko; Jacques Ravel; Lauren M. Brinkac; Robert T. DeBoy; Craig T. Parker; Sean C. Daugherty; Robert J. Dodson; A. Scott Durkin; Ramana Madupu; Steven A. Sullivan; Jyoti U. Shetty; Mobolanle A. Ayodeji; Alla Shvartsbeyn; Michael C. Schatz; Jonathan H. Badger; Claire M. Fraser; Karen E. Nelson

    2005-01-01

    Sequencing and comparative genome analysis of four strains of Campylobacter including C. lari RM2100, C. upsaliensis RM3195, and C. coli RM2228 has revealed major structural differences that are associated with the insertion of phage- and plasmid-like genomic islands, as well as major variations in the lipooligosaccharide complex. Poly G tracts are longer, are greater in number, and show greater variability

  7. Water flow measurement in large bore pipes: an experimental comparison between two different types of insertion flowmeters.

    PubMed

    Cascetta, Furio; Palombo, Adolfo; Scalabrini, Gianfranco

    2003-04-01

    In this paper the metrological behavior of two different insertion flowmeters (magnetic and turbine types) in large water pipes is described. A master-slave calibration was carried out in order to estimate the overall uncertainty of the tested meters. The experimental results show that (i) the magnetic insertion tested flowmeter performs the claimed accuracy (+/- 2%) within all the flow range (20:1); (ii) the insertion turbine tested meter, instead, reaches the claimed accuracy just in the upper zone of the flow range. PMID:12708537

  8. Investigation of Phenolic Profiles, Cytotoxic Potential and Phytochemical Screening of Different Extracts of Drynaria quercifolia J. Smith (Leaves)

    PubMed Central

    Runa, Jannatul Ferdous; Hossain, Marjan; Hasanuzzaman, Md.; Ali, Md. Ramjan

    2013-01-01

    Purpose: The present study is aimed to evaluate phenolic profiles, cytotoxic activity and phytochemical screening of different extracts of Drynaria quercifolia leaves. Methods: The dried and powder leaves were extracted with methanol at room temperature and the concentrated methanolic extract was fractionated by the modified Kupchan partitioning method to provide pet-ether, carbon tetrachloride, chloroform and aqueous soluble fractions. Phenolic profiles were determined by using Folin-Ciocalteau reagent, which results were expressed in gallic acid equivalent (mg of GAE/g of sample). Phytochemical properties of different extractives of plant materials were tested by the method of Trease and Evans. Brine shrimp lethality bioassay was used to investigate the cytotoxic potential of D. quercifolia. Results: The phytochemical screening revealed the potent source of different phytochemical constituents on different extractives including alkaloid, glycosides, tannin, saponins, proteins and amino acids, flavonoids, triterpenes, phenols, phytosterols and carbohydrate. In the determination of phenolic profiles, different extractives showed a significant content of phenolic compounds ranging from 103.43 -132.23 mg of GAE/g of extractive. Compared to vincristine sulfate different extractives of plant materials demonstrated moderate cytotoxic potential (having LC50 of 12.45 ?g/ml, 13.02 ?g/ml 15.83 ?g/ml, 14.95 ?g/ml and 7.612 ?g/ml, respectively). Conclusion: It is concluded from this study that D. quercifolia is an excellent source of phenolic content and phytoconstitutes as well as possesses moderate cytotoxic activity. PMID:24312880

  9. Two highly homologous phospholipase D isoenzymes from Papaver somniferum L. with different transphosphatidylation potential.

    PubMed

    Lerchner, Alexandra; Mansfeld, Johanna; Schäffner, Ines; Schöps, Regina; Beer, Helge K; Ulbrich-Hofmann, Renate

    2005-12-15

    The genes of two phospholipase D (PLD) isoenzymes, PLD1 and PLD2, from poppy seedlings (2829 and 2828 bp) were completely sequenced. The two genes have 96.9% identity in the encoding region and can be assigned to the alpha-type of plant PLDs. The corresponding amino acid sequences do not contain any signal sequences. One Asn-glycosylation site, six and two phosphorylation sites for protein kinase C and tyrosine kinase, respectively, and two phosphatidylinositol-4,5-bisphosphate binding motifs could be identified. Like in most plant PLDs, two HKD motifs and one C2 domain are present. PLD1 and PLD2 have ten and nine cysteine residues. The two enzymes were expressed in E. coli and purified to homogeneity by Ca2+ ion-mediated hydrophobic interaction chromatography. The Ca2+ ion concentration needed for carrier binding of the two enzymes in chromatography as well as for optimum activity was found to be considerably higher (>100 mM) than with other alpha-type plant PLDs. Although PLD1 and PLD2 differ in eleven amino acids only, they showed remarkable differences in their transphosphatidylation activity. Two amino acid exchanges within and near the first HKD motif contribute to this difference as shown by the A349E/E352Q-variant of PLD2. PMID:16257263

  10. Operant (biofeedback) control of left-right frontal alpha power differences: potential neurotherapy for affective disorders.

    PubMed

    Rosenfeld, J P; Cha, G; Blair, T; Gotlib, I H

    1995-09-01

    Two experiments were done with subjects from a paid pool of undergraduates. In each study, there were five 1-hour sessions on each of 5 days: (1) Baseline: Rewards given for randomly selected 20% of the 700-ms sequential epochs; mean and SD of baseline power differences determined. 2) Exploration: Subjects were rewarded when right minus left alpha differences in an epoch were greater than the baseline mean plus about .85 SD (p = .20); subjects told to discover how to generate rewards. (3)-(5). Training: Subjects were paid (over and above the $8/h flat rate) in proportion to their hit rates. In the first study (in which active filters passed 8-12 Hz activity, and the rectified, integrated amplitude was utilized), 6 of 8 subjects met learning criteria (a significant difference between baseline and training scores). In the second study (in which on-line FFTs were used to extract alpha power), 3 of 5 subjects met learning criteria. PMID:7495918

  11. Investigation of the Potential Difference between C60 and TiOPc on Ag(111) by Local Probe Techniques

    NASA Astrophysics Data System (ADS)

    Burson, Kristen; Wei, Yinying; Cullen, William; Reutt-Robey, Janice

    2011-03-01

    One challenge for increasing efficiency of organic photovoltaics is to understand the barrier to exciton separation that exists at the interface between organic molecules. Here we report a local probe measurement of the potential barrier at the interface between submonolayer C60, a good electron acceptor, and honeycomb phase TiOPc, an organic with high hole mobility, on Ag(111). We employ UHV AFM (atomic force microscopy) and KPFM (Kelvin probe force microscopy) to obtain simultaneous images of the potential and topographic landscapes. This technique allows for high spatial resolution of both the potential and the topography. In addition to reporting the work function difference between C60 and TiOPc, we investigate the work function for C60 on Ag(111).

  12. Regional differences in the potential exposure of US minority populations to hazardous facilities

    SciTech Connect

    Nieves, L.A. [Argonne National Lab., IL (United States); Nieves, A.L. [Wheaton Coll., Wheaton, IL (United States)]|[Argonne National Lab., IL (United States)

    1992-12-01

    In the literature that examines the distribution of environmental disamenities of various types, there is considerable documentation that minority groups and lower income groups are more likely to be exposed. Such differential exposure has been attributed to ``environmental racism`` by some authors, but there has been no systematic investigation of the factors and dynamics underlying this exposure pattern. This study examines regional differences in the proximity of African-American, Hispanics, Asians, and non-Hispanic Whites to a broad range facility types and explores the degree to which this may be related to urban and income factors.

  13. Regional differences in the potential exposure of US minority populations to hazardous facilities

    SciTech Connect

    Nieves, L.A. (Argonne National Lab., IL (United States)); Nieves, A.L. (Wheaton Coll., Wheaton, IL (United States) Argonne National Lab., IL (United States))

    1992-01-01

    In the literature that examines the distribution of environmental disamenities of various types, there is considerable documentation that minority groups and lower income groups are more likely to be exposed. Such differential exposure has been attributed to environmental racism'' by some authors, but there has been no systematic investigation of the factors and dynamics underlying this exposure pattern. This study examines regional differences in the proximity of African-American, Hispanics, Asians, and non-Hispanic Whites to a broad range facility types and explores the degree to which this may be related to urban and income factors.

  14. Age-related differences in event-related potentials for early visual processing of emotional faces.

    PubMed

    Hilimire, Matthew R; Mienaltowski, Andrew; Blanchard-Fields, Fredda; Corballis, Paul M

    2014-07-01

    With advancing age, processing resources are shifted away from negative emotional stimuli and toward positive ones. Here, we explored this 'positivity effect' using event-related potentials (ERPs). Participants identified the presence or absence of a visual probe that appeared over photographs of emotional faces. The ERPs elicited by the onsets of angry, sad, happy and neutral faces were recorded. We examined the frontocentral emotional positivity (FcEP), which is defined as a positive deflection in the waveforms elicited by emotional expressions relative to neutral faces early on in the time course of the ERP. The FcEP is thought to reflect enhanced early processing of emotional expressions. The results show that within the first 130 ms young adults show an FcEP to negative emotional expressions, whereas older adults show an FcEP to positive emotional expressions. These findings provide additional evidence that the age-related positivity effect in emotion processing can be traced to automatic processes that are evident very early in the processing of emotional facial expressions. PMID:23677489

  15. Identifying the Potential for Robotics to Assist Older Adults in Different Living Environments.

    PubMed

    Mitzner, Tracy L; Chen, Tiffany L; Kemp, Charles C; Rogers, Wendy A

    2014-04-01

    As the older adult population grows and becomes more diverse, so will their needs and preferences for living environments. Many adults over 65 years of age require some assistance [1, 2]; yet it is important for their feelings of well-being that the assistance not restrict their autonomy [3]. Not only is autonomy correlated with quality of life [4], autonomy enhancement may improve functionality [2, 5]. The goal of this paper is to provide guidance for the development of technology to enhance autonomy and quality of life for older adults. We explore the potential for robotics to meet these needs. We evaluated older adults' diverse living situations and the predictors of residential moves to higher levels of care in the United States. We also examined older adults' needs for assistance with activities of daily living (ADLs), instrumental activities of daily living (IADLs), and medical conditions when living independently or in a long-term care residence. By providing support for older adults, mobile manipulator robots may reduce need-driven, undesired moves from residences with lower levels of care (i.e., private homes, assisted living) to those with higher levels of care (i.e., skilled nursing). PMID:24729800

  16. Thrombin mitogenic responses and protein phosphorylation are different in cultured human endothelial cells derived from large and microvessels

    SciTech Connect

    Dupuy, E.; Bikfalvi, A.; Rendu, F.; Toledano, S.L.; Tobelem, G. (INSERM U 150, Paris (France))

    1989-12-01

    It is well established that thrombin induces various biological responses in endothelial cells derived from large vessels. However, little is known about the effects of thrombin on the microvasculature. Protein phosphorylation may be one of the mechanisms by which an extracellular stimulus initiates cellular events like proliferation. Therefore, we have compared the effects of either human alpha-thrombin or phorbol esters (TPA) on the proliferation or protein phosphorylation in endothelial cells derived from large vessels (umbilical vein, HUVEC) or microvessels (omental tissue, HOMEC). In HOMEC, thrombin did not stimulate cell proliferation and protein phosphorylation while TPA slightly reduced the cell proliferation and induced the phosphorylation of a 27-kDa protein. In contrast, in HUVEC, thrombin or TPA markedly enhanced the cell proliferation and stimulated the phosphorylation of a 59-kDa protein. These data indicate that endothelial cells from large and small vessels respond differently to thrombin and there is a complex and as yet unclear relationship between the proliferation and the protein phosphorylation induced by thrombin.

  17. Changing redox potential by controlling soil moisture and addition of inorganic oxidants to dissipate pentachlorophenol in different soils.

    PubMed

    Lin, Jiajiang; He, Yan; Xu, Jianming

    2012-11-01

    The potential for dissipation of pentachlorophenol (PCP) was investigated in soils from four different sites in China. These were an umbraqualf (Soil 1), a Plinthudult (Soil 2), a Haplustalf (Soil 3) and an Argiustoll (Soil 4) which were either flooded, to produce anaerobic conditions, or incubated aerobically at 60% water-holding capacity (WHC). The dissipation of PCP in Soil 1 at 60% WHC was higher than under flooded condition, while the opposite occurred in the other three soils. Under flooded conditions, the redox potential decreased significantly in Soil 1 and Soil 4, where sulphate reduction was occurred and the dissipation of PCP was statistically significant (about 96% and 98%, respectively) at the end of incubation. After addition of inorganic oxidants, dissipation of PCP was significantly inhibited by FeCl(3), while Na(2)SO(4) and NaNO(3) had different effects, depending upon the soil type. PMID:22842055

  18. Major Structural Differences and Novel Potential Virulence Mechanisms from the Genomes of Multiple Campylobacter Species

    PubMed Central

    2005-01-01

    Sequencing and comparative genome analysis of four strains of Campylobacter including C. lari RM2100, C. upsaliensis RM3195, and C. coli RM2228 has revealed major structural differences that are associated with the insertion of phage- and plasmid-like genomic islands, as well as major variations in the lipooligosaccharide complex. Poly G tracts are longer, are greater in number, and show greater variability in C. upsaliensis than in the other species. Many genes involved in host colonization, including racR/S, cadF, cdt, ciaB, and flagellin genes, are conserved across the species, but variations that appear to be species specific are evident for a lipooligosaccharide locus, a capsular (extracellular) polysaccharide locus, and a novel Campylobacter putative licABCD virulence locus. The strains also vary in their metabolic profiles, as well as their resistance profiles to a range of antibiotics. It is evident that the newly identified hypothetical and conserved hypothetical proteins, as well as uncharacterized two-component regulatory systems and membrane proteins, may hold additional significant information on the major differences in virulence among the species, as well as the specificity of the strains for particular hosts. PMID:15660156

  19. Risk Factors for Group B Streptococcal Colonization: Potential for Different Transmission Systems by Capsular Type

    PubMed Central

    Foxman, B.; Gillespie, B. W.; Manning, S. D.; Marrs, C. F.

    2007-01-01

    Purpose Group B Streptococcus (GBS) is a common inhabitant of the bowel and vaginal flora, with known transmission routes including sexual contact and vertical transmission from mother to infant. Foodborne transmission is also possible, as GBS is a known fish and bovine pathogen. We conducted a prospective cohort study in order to identify risk factors for acquisition. Methods We identified risk factors for GBS acquisition among college women (n=129) and men (n=128) followed at 3-week intervals for 3 months. Results A doubling in sex acts significantly increased incidence of capsular type V by 80% (95% CI: 1.19, 2.58), and other non-Ia or Ib types combined by 40% (95% CI: 1.00, 2.06; incidence of capsular type Ia (OR=1.2; 95% CI: 0.71, 1.88 p=0.57) and Ib (OR=1.5, 95% CI: 0.75, 2.86, p=0.27) were elevated although not significantly. After adjustment for sexual activity and sexual history, gender, and eating venue, fish consumption increased risk of acquiring capsular types Ia and Ib combined 7.3 fold (95% CI: 2.34, 19.50), but not other capsular types. Beef and milk were not associated with GBS incidence. Conclusions Different GBS capsular types may have different transmission routes. PMID:17689259

  20. Potential effects of climate change on the water level, flora and macro-fauna of a large neotropical wetland.

    PubMed

    Úbeda, Bárbara; Di Giacomo, Adrian S; Neiff, Juan José; Loiselle, Steven A; Poi, Alicia S Guadalupe; 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

  1. Comparison diel signal of electrical potential differences in the trunk of trees with other eco-hydrological phenomena

    NASA Astrophysics Data System (ADS)

    Koppan, A.; Kalicz, P.; Gribovszki, Z.; Vig, P.

    2009-04-01

    Diel fluctuation of hydrological features in forested lands is not a highly researched area. Many of the details of geophysical effects on the eco-hydrological phenomena in forest covered areas are poorly understood, too. In this paper some meteorological (net radiation, temperature, relative humidity data) and eco-hydrological (electrical potential differences data measured on the trunk of riparian trees, riparian groundwater level and stream base-flow data) parameters have been compared at a small time scale under forest covered environmental conditions. Analysed data set was measured at the outlet streamside point of the Hidegvíz Valley experimental catchment located at the eastern border of Alps. Meteorological data have been recorded by a micrometeorological station in the neighbourhood of streamflow, groundwater level reading and electrical potential differences measuring sensors. Groundwater level and streamflow discharges were calculated from data of water pressure principle functioning sensor. Electrical potential differences (EPD) have been recorded for several years between electrodes inserted in sixteen selected sites of trunks of two Alder trees (Alnus Glutinosa L.). The measured EPDs are related to the xylem-sapflow density. All of the examined eco-hydrological phenomenon are induced by the evapotranspiration. Therefore Penman-Monteith evapotranspiration rate were calculated on the basis of meteorological data for comparison of EPD, groundwater and streamflow signal. Detailed stochastic analysis (like dynamic spectrum, cross-correlation analysis etc.) was employed on the detrended eco-hydrological data series. These initial results help us better understanding of atmosphere, vegetation, water relationship in case of a streamside zone in hilly region. Keywords: diel fluctuation, electrical potential differences, sap flow, evapotranspiration

  2. Interactive Effect of Sulfur and Nitrogen on Nitrogen Accumulation and Harvest in Oilseed Crops Differing in Nitrogen Assimilation Potential

    Microsoft Academic Search

    I. S. Fazili; A. Jamal; S. Ahmad; Muzain Masoodi; J. S. Khan; M. Z. Abdin

    2008-01-01

    Field experiments were conducted to determine the interactive effect of sulfur (S) and nitrogen (N) on nitrogen accumulation, its distribution in various plant parts, and nitrogen harvest of oilseed crops viz. rapeseed (Brassica campestris L. cv. ‘Pusa Gold’) and taramira (Eruca sativa Mill.) differing in their N-assimilation potential. Two combinations of S and N (in Kg\\/ha): 0S + 100N (?S+N)

  3. Differences in passenger car and large truck involved crash frequencies at urban signalized intersections: an exploratory analysis.

    PubMed

    Dong, Chunjiao; Clarke, David B; Richards, Stephen H; Huang, Baoshan

    2014-01-01

    The influence of intersection features on safety has been examined extensively because intersections experience a relatively large proportion of motor vehicle conflicts and crashes. Although there are distinct differences between passenger cars and large trucks-size, operating characteristics, dimensions, and weight-modeling crash counts across vehicle types is rarely addressed. This paper develops and presents a multivariate regression model of crash frequencies by collision vehicle type using crash data for urban signalized intersections in Tennessee. In addition, the performance of univariate Poisson-lognormal (UVPLN), multivariate Poisson (MVP), and multivariate Poisson-lognormal (MVPLN) regression models in establishing the relationship between crashes, traffic factors, and geometric design of roadway intersections is investigated. Bayesian methods are used to estimate the unknown parameters of these models. The evaluation results suggest that the MVPLN model possesses most of the desirable statistical properties in developing the relationships. Compared to the UVPLN and MVP models, the MVPLN model better identifies significant factors and predicts crash frequencies. The findings suggest that traffic volume, truck percentage, lighting condition, and intersection angle significantly affect intersection safety. Important differences in car, car-truck, and truck crash frequencies with respect to various risk factors were found to exist between models. The paper provides some new or more comprehensive observations that have not been covered in previous studies. PMID:24140813

  4. Potential of Olfactory Ensheathing Cells from Different Sources for Spinal Cord Repair

    PubMed Central

    Mayeur, Anne; Duclos, Célia; Honoré, Axel; Gauberti, Maxime; Drouot, Laurent; do Rego, Jean-Claude; Bon-Mardion, Nicolas; Jean, Laetitia; Vérin, Eric; Emery, Evelyne; Lemarchant, Sighild; Vivien, Denis; Boyer, Olivier; Marie, Jean-Paul; Guérout, Nicolas

    2013-01-01

    Spinal cord injury (SCI) induces a permanent disability in patients. To this day no curative treatment can be proposed to restore lost functions. Therefore, extensive experimental studies have been conducted to induce recovery after SCI. One of the most promising therapies is based on the use of olfactory ensheathing cells (OECs). OECs can be obtained from either the olfactory bulbs (OB-OECs) or from olfactory mucosa (OM-OECs), involving a less invasive approach for autotransplantation. However the vast majority of experimental transplantations have been focusing on OB-OECs although the OM represents a more accessible source of OECs. Importantly, the ability of OM-OECs in comparison to OB-OECs to induce spinal cord recovery in the same lesion paradigm has never been described. We here present data using a multiparametric approach, based on electrophysiological, behavioral, histological and magnetic resonance imaging experiments on the repair potential of OB-OECs and OM-OECs from either primary or purified cultures after a severe model of SCI. Our data demonstrate that transplantation of OECs obtained from OB or OM induces electrophysiological and functional recovery, reduces astrocyte reactivity and glial scar formation and improves axonal regrowth. We also show that the purification step is essential for OM-OECs while not required for OB-OECs. Altogether, our study strongly indicates that transplantation of OECs from OM represents the best benefit/risk ratio according to the safety of access of OM and the results induced by transplantations of OM-OECs. Indeed, purified OM-OECs in addition to induce recovery can integrate and survive up to 60 days into the spinal cord. Therefore, our results provide strong support for these cells as a viable therapy for SCI. PMID:23638158

  5. Metal oxide-based nanoparticles: revealing their potential to enhance oil recovery in different wettability systems

    NASA Astrophysics Data System (ADS)

    Hendraningrat, Luky; Torsæter, Ole

    2015-02-01

    This paper presents systematic studies of hydrophilic metal oxide nanoparticles (NPs) dispersed in brine intended to reveal their potential to enhance oil recovery (EOR) in various rock wettability systems. The stability in suspension (nanofluid) of the NPs has been identified as a key factor related to their use as an EOR agent. Experimental techniques have been developed for nanofluid stability using three coupled methods: direct visual observation, surface conductivity and particle size measurements. The use of a dispersant has been investigated and has been shown to successfully improve metal oxide nanofluid stability as a function of its concentration. The dispersant alters the nanofluid properties, i.e. surface conductivity, pH and particle size distribution. A two-phase coreflood experiment was conducted by injecting the stable nanofluids as a tertiary process (nano-EOR) through core plugs with various wettabilities ranging from water-wet to oil-wet. The combination of metal oxide nanofluid and dispersant improved the oil recovery to a greater extent than either silica-based nanofluid or dispersant alone in all wettability systems. The contact angle, interfacial tension (IFT) and effluent were also measured. It was observed that metal oxide-based nanofluids altered the quartz plates to become more water-wet, and the results are consistent with those of the coreflood experiment. The particle adsorption during the transport process was identified from effluent analysis. The presence of NPs and dispersant reduced the IFT, but its reduction is sufficient to yield significant additional oil recovery. Hence, wettability alteration plays a dominant role in the oil displacement mechanism using nano-EOR.

  6. Developmental potential of bovine oocytes cultured in different maturation and culture conditions.

    PubMed

    Sagirkaya, Hakan; Misirlioglu, Muge; Kaya, Abdullah; First, Neal L; Parrish, John J; Memili, Erdogan

    2007-10-01

    Diverse groups of chemicals in culture media are needed for successful bovine oocyte maturation and embryo development during which dramatic cytoplasmic and nuclear reprogramming events take place. In vitro embryo production (IVP) procedures frequently include supplements such as serum and/or co-culture with various types of somatic cells. However, the presence of undefined serum in culture media introduces a variation from batch to batch, increases viral or prion contamination risk, and leads to problems during fetal development. The aim of the present study was to investigate the possibility of using chemically defined-synthetic serum substitute (SSS) in place of fetal calf serum (FCS) during maturation and long-term culture to stimulate in vitro maturation (IVM), fertilization (IVF) and subsequent embryo development. In Experiment I, the effect of the protein source on in vitro maturation was tested by maturing oocytes in culture media supplemented with 10% FCS (Control Group), 10% SSS (Group I) and 10% SSS+10 ng/ml epidermal growth factor (EGF) (Group II). In Experiment II, effects of SSS on both oocyte maturation and embryo development during in vitro culture (IVC) were tested by maturing oocytes in media supplemented with 10% FCS (FCS Group) or 10% SSS+10 ng/ml EGF (SSS Group), followed by IVF and IVC in SOF media supplemented with 10% FCS and 10% SSS on day 4 for FCS and SSS Groups, respectively. Even though rates for cleavage and development to blastocyst stage were not different, blastocyst cell numbers were higher in Group II containing SSS and EGF. The SSS supplementation group had higher apoptotic nuclei as compared to the FCS Group in Experiment II. Transcripts for heat shock protein 70 (Hsp70), interferon tau (IF-tau), DNA methyltransferase 3a (Dnmt3a), desmosomal glycoprotein desmocollin III (DcIII) and insulin-like growth factor II receptor (Igf-2r) were altered in different culture conditions in Experiment I. However, only glucose transporter-1 (Glut-1) mRNA was different in the SSS and FCS Groups in the second experiment. In summary, SSS and EGF in maturation medium and replacement of FCS with SSS alone in culture medium on day 4 of IVC support oocyte maturation and embryo development in vitro. However, significance of culture condition induced changes on the genome-wide abundance of messenger ribonucleic acid and the significance of the apoptotic nuclei during fetal development still remain to be determined. PMID:17052869

  7. Cell specific differences between human adipose-derived and mesenchymal–stromal cells despite similar differentiation potentials

    Microsoft Academic Search

    Danièle Noël; David Caton; Stéphane Roche; Claire Bony; Sylvain Lehmann; Louis Casteilla; Christian Jorgensen; Béatrice Cousin

    2008-01-01

    Stromal cells from bone marrow and adipose tissue are attractive sources of adult progenitors for cell-based therapy. However, whether those cell populations represent intrinsically different cell types is still largely under debate. The aim of this study was to systematically and quantitatively compare adipose-derived stromal cells (ADSC) and bone marrow-derived multipotent mesenchymal–stromal cells (BM-MSC). The quantitative comparison was realized using

  8. Epithelial and subepithelial resistance of rat large intestine: segmental differences, effect of stripping, time course, and action of aldosterone.

    PubMed

    Schulzke, J D; Fromm, M; Hegel, U

    1986-12-01

    Epithelial and subepithelial electrical resistances of rat large intestine were measured by means of a 4-electrode AC impedance technique in three segments, colon ascendens, colon descendens and rectum. Epithelial resistance of colon ascendens and colon descendens was about 35 omega X cm2 and not different between these two segments. It was, however, about 3 times higher in rectum (99 omega X cm2). This finding is in accord with our previous observation of about 3-fold higher net fluxes of ions and water in colon ascendens and colon descendens than in rectum. It confirms the concept of a main functional difference between the terminal part of the large intestine (rectum) and the more proximal segments (colon). The acutely (within hours) varied level of aldosterone by keeping the rats for 7 h in anaesthesia caused in the rectum a more than 10-fold increase in short circuit current (Isc) and transepithelial voltage but no significant decrease in resistance. Similarly, the decline in Isc, as regularly observed in the early phase of in vitro measurements on partially stripped large intestine, was paralleled by voltage changes but not by changes in resistance. We conclude that the wide range of resistance values published so far was caused to a great extent by including various portions of colon or rectum. By comparing intact (not stripped) and partially stripped preparations (muscularis propria removed) of the rectum it was shown that partial stripping did not alter the epithelial resistance but reduced the subepithelial resistance in this segment from 26 to 8 omega X cm2, or by 68%.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3797217

  9. Large interclone differences in melezitose secretion in the facultatively ant-tended black bean aphid Aphis fabae.

    PubMed

    Vantaux, A; Van den Ende, W; Billen, J; Wenseleers, T

    2011-12-01

    Many aphids are known to engage in a trophic mutualism with ants, whereby the aphids secrete sugary-rich honeydew which is collected by the ants for food, and the ants, in exchange, protect the aphids against natural enemies. Previous results, however, suggest that the production of some of the honeydew sugars, such as the ant-attractant trisaccharide melezitose, may induce an indirect cost to the aphids. This led us to believe that large differences in the nature of the secreted honeydew might exist, due to some clones capitalizing more or less on their mutualistic interaction with ants, or due to some "cheater" clones foregoing the production of particular sugars, instead taking advantage of the ant-attracting effect of other non sugar-deficient clones, co-occurring on the same plant. Here we present data on clonal variation in the composition of honeydew of the black bean aphid Aphis fabae which confirm this prediction. In particular, our results show that there was large interclone variation in the amount of glucose, melezitose and total sugar produced. The variation in the production of melezitose, however, showed particularly large differences, with 54% (7 out of 13) of the clones screened being virtually deficient for the production of this sugar, irrespective of whether the aphid colonies were ant-tended or not. The consequences of this finding in the context of the evolution and maintenance of the ant-aphid mutualism, as well as the adaptive benefits of oligosaccharide synthesis in aphids and other insects are discussed. PMID:21896277

  10. Modeling a Cortical Auxin Maximum for Nodulation: Different Signatures of Potential Strategies

    PubMed Central

    Deinum, Eva Elisabeth; Geurts, René; Bisseling, Ton; Mulder, Bela M.

    2012-01-01

    Lateral organ formation from plant roots typically requires the de novo creation of a meristem, initiated at the location of a localized auxin maximum. Legume roots can form both root nodules and lateral roots. From the basic principles of auxin transport and metabolism only a few mechanisms can be inferred for increasing the local auxin concentration: increased influx, decreased efflux, and (increased) local production. Using computer simulations we investigate the different spatio-temporal patterns resulting from each of these mechanisms in the context of a root model of a generalized legume. We apply all mechanisms to the same group of preselected cells, dubbed the controlled area. We find that each mechanism leaves its own characteristic signature. Local production by itself can not create a strong auxin maximum. An increase of influx, as is observed in lateral root formation, can result in an auxin maximum that is spatially more confined than the controlled area. A decrease of efflux on the other hand leads to a broad maximum, which is more similar to what is observed for nodule primordia. With our prime interest in nodulation, we further investigate the dynamics following a decrease of efflux. We find that with a homogeneous change in the whole cortex, the first auxin accumulation is observed in the inner cortex. The steady state lateral location of this efflux reduced auxin maximum can be shifted by slight changes in the ratio of central to peripheral efflux carriers. We discuss the implications of this finding in the context of determinate and indeterminate nodules, which originate from different cortical positions. The patterns we have found are robust under disruption of the (artificial) tissue layout. The same patterns are therefore likely to occur in many other contexts. PMID:22654886

  11. Toxicity of four potentially ichthyotoxic marine phytoflagellates determined by four different test methods.

    PubMed

    Meldahl, A S; Edvardsen, B; Fonnum, F

    1994-07-01

    The toxicity of the marine phytoflagellates Prymnesium parvum. Prymnesium patelliferum, Chrysochromulina polylepis, and Chrysochromulina leadbeateri isolated from ichthyotoxic blooms in Norwegian coastal waters was compared using four different test methods developed for the detection of toxins produced by these species. The test methods were (1) lethality to the crustacean Artemia salina exposed to living algae, (2) hemolytic activity (lysis of human erythrocytes) by crude algal lipid extracts, and inhibition of the uptake of the neurotransmitters L-glutamate and gamma-aminobutyric acid (GABA) into (3) synaptosomes and (4) synaptic vesicles of rat brain by crude algal lipid extracts. All test methods indicated different levels of toxicity among the algal species. Prymnesium parvum, P. patelliferum, and C. polylepis were toxic as determined by all four test methods. The cultured strain of C. leadbeateri, although isolated from a toxic algal bloom, appeared nontoxic by the methods used here, and served as a negative control. The hemolytic activity of P. parvum extract was about nine times higher than that of P. patelliferum extract, whereas the activity was only two to three times higher using the other three methods. Chrysochromulina polylepis had higher toxic activity than P. patelliferum except for less inhibitory effect on synaptosomes. The inhibition of synaptosomal and vesicular neurotransmitter uptake systems by extracts of P. parvum, P. patelliferum, and C. polylepis appeared to be due to similar mechanisms of action, since similar inhibition ratios between the uptake of L-glutamate and GABA were obtained in both synaptosomes and synaptic vesicles. We suggest that P. parvum, P. patelliferum, and C. polylepis produce a set of similar toxins and that the relative amounts of each toxin vary among the three species. PMID:7912738

  12. Two different spectrophotometric determinations of potential anticancer drug and its toxic metabolite

    NASA Astrophysics Data System (ADS)

    Farid, Nehal F.; Abdelwahab, Nada S.

    2015-06-01

    Flutamide is a hormone therapy used for men with advanced prostate cancer. Flutamide is highly susceptible to hydrolysis with the production of 3-(trifluoromethyl)aniline, which is reported to be one of its toxic metabolites, impurities and related substances according to BP and USP. Flutamide was found to be stable when exposed to oxidation by 30% hydrogen peroxide and direct sunlight for up to 4 h. Two accurate and sensitive spectrophotometric methods were used for determination of flutamide in bulk and in pharmaceutical formulations. Method (I) is the area under curve (AUC) spectrophotometric method that depends on measuring the AUC in the wavelength ranges of 275-305 nm and 350-380 nm and using Cramer's rule. The linearity range was found to be 1-35 ?g/mL and 0.5-16 ?g/mL for the drug and the degradate, respectively. In method (II), combination of the isoabsorptive and dual wavelength spectrophotometric methods was used for resolving the binary mixture. The absorbance at 249.2 nm (?iso) was used for determination of total mixture concentration, while the difference in absorbance between 232 nm and 341.2 nm was used for measuring the drug concentration. By subtraction, the degradate concentration was obtained. Beer's law was obeyed in the range of 2-35 ?g/mL and 0.5-20 ?g/mL for the drug and its degradate, respectively. The two methods were validated according to USP guidelines and were applied for determination of the drug in its pharmaceutical dosage form. Moreover AUC method was used for the kinetic study of the hydrolytic degradation of flutamide. The kinetic degradation of flutamide was found to follow pseudo-first order kinetics and is pH and temperature dependent. Activation energy, kinetic rate constants and t1/2 at different temperatures and pH values were calculated.

  13. Two different spectrophotometric determinations of potential anticancer drug and its toxic metabolite.

    PubMed

    Farid, Nehal F; Abdelwahab, Nada S

    2015-06-15

    Flutamide is a hormone therapy used for men with advanced prostate cancer. Flutamide is highly susceptible to hydrolysis with the production of 3-(trifluoromethyl)aniline, which is reported to be one of its toxic metabolites, impurities and related substances according to BP and USP. Flutamide was found to be stable when exposed to oxidation by 30% hydrogen peroxide and direct sunlight for up to 4h. Two accurate and sensitive spectrophotometric methods were used for determination of flutamide in bulk and in pharmaceutical formulations. Method (I) is the area under curve (AUC) spectrophotometric method that depends on measuring the AUC in the wavelength ranges of 275-305nm and 350-380nm and using Cramer's rule. The linearity range was found to be 1-35?g/mL and 0.5-16?g/mL for the drug and the degradate, respectively. In method (II), combination of the isoabsorptive and dual wavelength spectrophotometric methods was used for resolving the binary mixture. The absorbance at 249.2nm (?iso) was used for determination of total mixture concentration, while the difference in absorbance between 232nm and 341.2nm was used for measuring the drug concentration. By subtraction, the degradate concentration was obtained. Beer's law was obeyed in the range of 2-35?g/mL and 0.5-20?g/mL for the drug and its degradate, respectively. The two methods were validated according to USP guidelines and were applied for determination of the drug in its pharmaceutical dosage form. Moreover AUC method was used for the kinetic study of the hydrolytic degradation of flutamide. The kinetic degradation of flutamide was found to follow pseudo-first order kinetics and is pH and temperature dependent. Activation energy, kinetic rate constants and t1/2 at different temperatures and pH values were calculated. PMID:25795610

  14. 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).

  15. Large vestibular evoked myogenic potentials in response to bone-conducted sounds in patients with superior canal dehiscence syndrome.

    PubMed

    Brantberg, Krister; Löfqvist, Lennart; Fransson, Per-Anders

    2004-01-01

    Dehiscence of the superior semicircular canal is a 'new' vestibular entity. Among these patients, the vestibular evoked myogenic potentials (VEMP) in response to air-conducted sounds are large. In the present study, VEMP in response to bone-conducted sounds were studied in 5 normal subjects, in 3 patients after (unilateral) labyrinthectomy and in 4 patients with (unilateral) superior canal dehiscence syndrome. The bone-conducted sound stimulus was a 250- and a 500- tone burst delivered monaurally on the mastoid using standard bone conductors. Among the normals, bone-conducted sounds delivered monaurally caused VEMP bilaterally. There was, however, a transcranial attenuation for the 500-Hz stimulus, but less so for the 250-Hz stimulus. Among the patients with labyrinthectomy there were VEMP on the healthy side, but not on the lesioned side, irrespective of whether the bone-conducted sounds were presented behind the healthy or the operated ear. Among the patients with superior canal dehiscence syndrome, the VEMP on the affected side were larger than on the healthy side. This suggests that there is also vestibular hypersensitivity for bone-conducted sounds in these patients. PMID:15084822

  16. Mislocalization of Large ARF-GEFs as a Potential Mechanism for BFA Resistance in COG-Deficient Cells

    PubMed Central

    Flanagan-Steet, Heather; Johnson, Steven; Smith, Richard D.; Bangiyeva, Julia; Lupashin, Vladimir; Steet, Richard

    2011-01-01

    Defects in subunits of the conserved oligomeric Golgi (COG) complex represent a growing subset of congenital disorders of glycosylation (CDGs). In addition to altered protein glycosylation and vesicular trafficking, Cog-deficient patient fibroblasts exhibit a striking delay in the Golgi-disrupting effects of brefeldin A (BFA). Despite the diagnostic value of this BFA resistance, the molecular basis of this response is not known. To investigate potential mechanisms of resistance, we analyzed the localization of the large ARF-GEF, GBF1, in several Cog-deficient cell lines. Our results revealed mislocalization of GBF1 to non-Golgi compartments, in particular the ERGIC, within these cells. Biochemical analysis of GBF1 in control and BFA-treated fibroblasts demonstrated that the steady-state level and membrane recruitment is not substantially affected by COG deficiency, supporting a role for the COG complex in the localization but not membrane association of GBF1. We also showed that pretreatment of fibroblasts with bafilomycin resulted in a GBF1-independent BFA resistance that appears additive with the resistance associated with COG deficiency. These data provide new insight into the mechanism of BFA resistance in Cog-deficient cells by suggesting a role for impaired ARF-GEF localization. PMID:21722633

  17. Recruitment potential of two perennial grasses with different growth forms at a semiarid-arid transition zone.

    PubMed

    Peters, Debra P C

    2002-10-01

    The objective of this study was to quantify differences in recruitment potential (seed production, seed presence in the soil) for two congeneric perennial grasses (Bouteloua gracilis, Bouteloua eriopoda [Poaceae]) that dominate adjacent arid and semiarid grassland biomes. It was hypothesized that these species have different recruitment strategies at the biome transition zone that are related to differences in their growth form and longevity. Recruitment potential for each Bouteloua species was compared in patches dominated by one or both species or codominated by the invasive shrub, Larrea tridentata (Zygophyllaceae). Regional variation in recruitment was examined for B. gracilis for cases in which comparable data were available in the literature for a site located within the semiarid grassland biome. The short-lived stoloniferous species B. eriopoda produced more seeds per plant than the long-lived bunchgrass B. gracilis, yet seed viability (<60%) and presence in the soil were lower. Mean viability of B. gracilis was higher (>90%) than that of B. eriopoda, and a greater percentage of seeds produced on a square meter basis was found in the soil (10-25%). Similar patterns were found for both species in all grass-dominated patches. Bouteloua eriopoda plants growing in patches codominated by L. tridentata produced fewer seeds per plant with lower viability, and fewer seeds were found in the soil compared to grass-dominated patches. Regional comparisons found greater seed production per square meter and more seeds in the soil for B. gracilis at the transitional site compared with a cooler, wetter site located within the semiarid grassland biome. These differences in recruitment potential along with published differences in rates of seedling establishment and vegetative spread may explain, at least in part, localized patterns in species dominance. PMID:21665589

  18. Occurrence and potential health risk of Cryptosporidium and Giardia in different water catchments in Belgium.

    PubMed

    Ehsan, Amimul; Geurden, Thomas; Casaert, Stijn; Paulussen, Jef; De Coster, Lut; Schoemaker, Toon; Chalmers, Rachel; Grit, Grietje; Vercruysse, Jozef; Claerebout, Edwin

    2015-02-01

    Human wastewater and livestock can contribute to contamination of surface water with Cryptosporidium and Giardia. In countries where a substantial proportion of drinking water is produced from surface water, e.g., Belgium, this poses a constant threat on drinking water safety. Our objective was to monitor the presence of Cryptosporidium and Giardia in different water catchment sites in Belgium and to discriminate between (oo)cysts from human or animal origin using genotyping. Monthly samples were collected from raw water and purified drinking water at four catchment sites. Cryptosporidium and Giardia were detected using USEPA method 1623 and positive samples were genotyped. No contamination was found in purified water at any site. In three catchments, only low numbers of (oo)cysts were recovered from raw water samples (<1/liter), but raw water samples from one catchment site were frequently contaminated with Giardia (92 %) and Cryptosporidium (96 %), especially in winter and spring. Genotyping of Giardia in 38 water samples identified the presence of Giardia duodenalis assemblage AI, AII, BIV, BIV-like, and E. Cryptosporidium andersoni, Cryptosporidium suis, Cryptosporidium horse genotype, Cryptosporidium parvum, and Cryptosporidium hominis were detected. The genotyping results suggest that agriculture may be a more important source of surface water contamination than human waste in this catchment. In catchment sites with contaminated surface water, such as the Blankaart, continuous monitoring of treated water for the presence of Cryptosporidium and Giardia would be justified and (point) sources of surface water contamination should be identified. PMID:25616782

  19. Influence of two different IR radiators on the antioxidative potential of the human skin

    NASA Astrophysics Data System (ADS)

    Darvin, M. E.; Patzelt, A.; Meinke, M.; Sterry, W.; Lademann, J.

    2009-03-01

    Resonance Raman spectroscopy was used for the fast in vivo detection of the concentration of carotenoid antioxidant substances such as beta-carotene and lycopene in human skin and for the measurement of their degradation dynamics, subsequent to infrared (IR) irradiation emitted by two different IR radiators applied at the same power density. One of the radiators was equipped with a water filter in front of the radiation source (WIRA) and the other was a usual broadband system without a water filter (standard IR radiator – SIR). It was found that the SIR exerted a higher influence on the degradation of carotenoids in the skin than the WIRA. Furthermore, all twelve volunteers who participated in the study felt that the irradiation with the SIR was disagreeably warmer on the skin surface compared to the WIRA, in spite of the same power density values for both radiators on the skin surface. The average degradation magnitude of the carotenoids in the skin of all volunteers after an IR irradiation was determined at 23% for WIRA and 33% for the SIR. A correlation (R2 ~ 0.6) was found between the individual level of carotenoids in the skin of the volunteers and the magnitude of degradation of the carotenoids for both IR radiators. Taking the previous investigations into consideration, which clearly showed production of free radicals in the skin subsequent to IR irradiation, it can be concluded that during the application of WIRA irradiation on the skin, fewer radicals are produced in comparison to the SIR.

  20. The Potential of Different Concepts of Fast Breeder Reactor for the French Fleet Renewal

    SciTech Connect

    Massara, Simone; Tetart, Philippe; Lecarpentier, David; Garzenne, Claude; Mourogov, Alexandre [Electricite de France, EDF R and D (France)

    2006-07-01

    The performances of different concepts of Fast Breeder Reactor (Na-cooled, He-cooled and Pb-cooled FBR) for the current French fleet renewal are analyzed in the framework of a transition scenario to a 100% FBR fleet at the end of the 21. century. Firstly, the modeling of these three FBR types by means of a semi-analytical approach in TIRELIRE - STRATEGIE, the EDF fuel cycle simulation code, is presented, together with some validation elements against ERANOS, the French reference code system for neutronic FBR analysis (CEA). Afterwards, performances comparisons are made in terms of maximum deployable power, natural uranium consumption and waste production. The results show that the FBR maximum deployable capacity, independently from the FBR technology, is highly sensitive to the fuel cycle options, like the spent nuclear fuel cooling time or the Minor Actinides management strategy. Thus, some of the key parameters defining the dynamic of FBR deployment are highlighted, to inform the orientation of R and D in the development and optimization of these systems. (authors)

  1. Effect of pulsed electric field treatment on hot-boned muscles of different potential tenderness.

    PubMed

    Suwandy, Via; Carne, Alan; van de Ven, Remy; Bekhit, Alaa El-Din A; Hopkins, David L

    2015-07-01

    In this study, the effect of pulsed electric field (PEF) treatment and ageing on the quality of beef M. longissimus lumborum (LL) and M. semimembranosus (SM) muscles was evaluated, including the tenderness, water loss and post-mortem proteolysis. Muscles were obtained from 12 steers (6 steers for each muscle), removed from the carcasses 4 hour postmortem and were treated with pulsed electric field within 2h. Six different pulsed electric field intensities (voltages of 5 and 10 kV × frequencies of 20, 50 and 90 Hz) plus a control were applied to each muscle to determine the optimum treatment conditions. Beef LL was found to get tougher with increasing treatment frequency whereas beef SM muscle was found to have up to 21.6% reduction in the shear force with pulsed electric field treatment. Post-mortem proteolysis showed an increase in both troponin and desmin degradation in beef LL treated with low intensity PEF treatment (20 Hz) compared to non-treated control samples. PMID:25754097

  2. The potential of different bio adsorbents for removing phenol from its aqueous solution.

    PubMed

    Abdallah, Maha Ahmed Mohamed

    2013-08-01

    The use of natural resources for the removal of phenol and phenolic compounds is being looked upon by researchers in preference to other prevailing methods. In the present study, different biosorbents, brown algae (Padina pavonia), fresh water macrophyta (Ceratophyllum demersum), and black tea residue, were tested as adsorbent for the removal of phenol from aqueous solutions. The optimum conditions for maximum adsorption in terms of concentration of the adsorbate and pH were identified. The results show that the initial concentration increases as the removal of phenol increases in C. demersum; in the case of the other two adsorbents, the initial concentration increases as the removal of phenol decreases, especially for an initial concentration lower than 100 and 1,000 ?g/L for P. pavonia and black tea residue, respectively. Maximum percentage removal of phenol by each adsorbent is 77, 50.8, and 29 % for C. demersum, P. pavonia, and black tea residue, respectively. Also, the biosorption capacity was strongly influenced by the pH of the aqueous solution with an observed maximum phenol removal at pH of around 6-10. The first biosorbent (black tea residue) displays the maximum adsorption capacity at a pH of 10 with a percentage sorption capacity of 84 %; P. pavonia revealed a greater adsorption percentage at pH?10, reaching 30 %, while for C. demersum, the removal of phenol increases with the increase in initial pH up to 6.0 and decreases drastically with further increase in initial pH. The Freundlich, Langmuir, and Brauner-Emmet-Teller adsorption models were applied to describe the equilibrium isotherms. The results reveal that the equilibrium data for all phenol adsorbents fitted the Freundlich model which seemed to be the best-fitting model for the experimental results with similar values of coefficient of determination. PMID:23242505

  3. Gender differences in methionine accumulation and metabolism in freshly isolated mouse hepatocytes: Potential roles in toxicity

    SciTech Connect

    Dever, Joseph T. [Department of Comparative Biosciences and Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, Wisconsin (United States); Elfarra, Adnan A. [Department of Comparative Biosciences and Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, Wisconsin (United States)], E-mail: aelfarra@wisc.edu

    2009-05-01

    L-Methionine (Met) is hepatotoxic at high concentrations. Because Met toxicity in freshly isolated mouse hepatocytes is gender-dependent, the goal of this study was to assess the roles of Met accumulation and metabolism in the increased sensitivity of male hepatocytes to Met toxicity compared with female hepatocytes. Male hepatocytes incubated with Met (30 mM) at 37 {sup o}C exhibited higher levels of intracellular Met at 0.5, 1.0, and 1.5 h, respectively, compared to female hepatocytes. Conversely, female hepatocytes had higher levels of S-adenosyl-L-methionine compared to male hepatocytes. Female hepatocytes also exhibited higher L-methionine-L-sulfoxide levels relative to control hepatocytes, whereas the increases in L-methionine-D-sulfoxide (Met-D-O) levels were similar in hepatocytes of both genders. Addition of aminooxyacetic acid (AOAA), an inhibitor of Met transamination, significantly increased Met levels at 1.5 h and increased Met-D-O levels at 1.0 and 1.5 h only in Met-exposed male hepatocytes. No gender differences in cytosolic Met transamination activity by glutamine transaminase K were detected. However, female mouse liver cytosol exhibited higher methionine-DL-sulfoxide (MetO) reductase activity than male mouse liver cytosol at low (0.25 and 0.5 mM) MetO concentrations. Collectively, these results suggest that increased cellular Met accumulation, decreased Met transmethylation, and increased Met and MetO transamination in male mouse hepatocytes may be contributing to the higher sensitivity of the male mouse hepatocytes to Met toxicity in comparison with female mouse hepatocytes.

  4. Effects of different culture conditions on biological potential and metabolites production in three Penicillium isolates.

    PubMed

    Reis, Filipa S; ?iri?, Ana; Stojkovi?, Dejan; Barros, Lillian; Ljaljevi?-Grbi?, Milica; Sokovi?, Marina; Ferreira, Isabel C F R

    2015-02-01

    The genus Penicillium is well known for its importance in drug and food production. Certain species are produced on an industrial scale for the production of antibiotics (e.g. penicillin) or for insertion in food (e.g. cheese). In the present work, three Penicillium species, part of the natural mycobiota growing on various food products were selected - P. ochrochloron, P. funiculosum and P. verrucosum var. cyclopium. The objective of our study was to value these species from the point of view of production of bioactive metabolites. The species were obtained after inoculation and growth in Czapek and Malt media. Both mycelia and culture media were analyzed to monitor the production of different metabolites by each fungus and their release to the culture medium. The concentrations of sugars, organic acids, phenolic acids and tocopherols were determined. Antioxidant activity of the phenolic extracts was evaluated, as also the antimicrobial activity of phenolic acids, organic acids and tocopherols extracts. Rhamnose, xylose, fructose and trehalose were found in all the mycelia and culture media; the prevailing organic acids were oxalic and fumaric acids, and protocatechuic and p-hydroxybenzoic acids were the most common phenolic acids; ?-tocopherol was the most abundant vitamin E isoform. Generally, the phenolic extracts corresponding to the mycelia samples revealed higher antioxidant activity. Concerning the antimicrobial activity there were some fluctuations, however all the studied species revealed activity against the tested strains. Therefore, the in-vitro bioprocesses can be an alternative for the production of bioactive metabolites that can be used by pharmaceutical industry. PMID:24261405

  5. The Analysis of Pendolino (peo) Mutants Reveals Differences in the Fusigenic Potential among Drosophila Telomeres

    PubMed Central

    Marzullo, Marta; Raffa, Grazia D.; Morciano, Patrizia; Raimondo, Domenico; Burla, Romina; Saggio, Isabella; Gatti, Maurizio

    2015-01-01

    Drosophila telomeres are sequence-independent structures that are maintained by transposition to chromosome ends of three specialized retroelements (HeT-A, TART and TAHRE; collectively designated as HTT) rather than telomerase activity. Fly telomeres are protected by the terminin complex (HOAP-HipHop-Moi-Ver) that localizes and functions exclusively at telomeres and by non-terminin proteins that do not serve telomere-specific functions. Although all Drosophila telomeres terminate with HTT arrays and are capped by terminin, they differ in the type of subtelomeric chromatin; the Y, XR, and 4L HTT are juxtaposed to constitutive heterochromatin, while the XL, 2L, 2R, 3L and 3R HTT are linked to the TAS repetitive sequences; the 4R HTT is associated with a chromatin that has features common to both euchromatin and heterochromatin. Here we show that mutations in pendolino (peo) cause telomeric fusions (TFs). The analysis of several peo mutant combinations showed that these TFs preferentially involve the Y, XR and 4th chromosome telomeres, a TF pattern never observed in the other 10 telomere-capping mutants so far characterized. peo encodes a non-terminin protein homologous to the E2 variant ubiquitin-conjugating enzymes. The Peo protein directly interacts with the terminin components, but peo mutations do not affect telomeric localization of HOAP, Moi, Ver and HP1a, suggesting that the peo-dependent telomere fusion phenotype is not due to loss of terminin from chromosome ends. peo mutants are also defective in DNA replication and PCNA recruitment. However, our results suggest that general defects in DNA replication are unable to induce TFs in Drosophila cells. We thus hypothesize that DNA replication in Peo-depleted cells results in specific fusigenic lesions concentrated in heterochromatin-associated telomeres. Alternatively, it is possible that Peo plays a dual function being independently required for DNA replication and telomere capping. PMID:26110638

  6. The Analysis of Pendolino (peo) Mutants Reveals Differences in the Fusigenic Potential among Drosophila Telomeres.

    PubMed

    Cenci, Giovanni; Ciapponi, Laura; Marzullo, Marta; Raffa, Grazia D; Morciano, Patrizia; Raimondo, Domenico; Burla, Romina; Saggio, Isabella; Gatti, Maurizio

    2015-06-01

    Drosophila telomeres are sequence-independent structures that are maintained by transposition to chromosome ends of three specialized retroelements (HeT-A, TART and TAHRE; collectively designated as HTT) rather than telomerase activity. Fly telomeres are protected by the terminin complex (HOAP-HipHop-Moi-Ver) that localizes and functions exclusively at telomeres and by non-terminin proteins that do not serve telomere-specific functions. Although all Drosophila telomeres terminate with HTT arrays and are capped by terminin, they differ in the type of subtelomeric chromatin; the Y, XR, and 4L HTT are juxtaposed to constitutive heterochromatin, while the XL, 2L, 2R, 3L and 3R HTT are linked to the TAS repetitive sequences; the 4R HTT is associated with a chromatin that has features common to both euchromatin and heterochromatin. Here we show that mutations in pendolino (peo) cause telomeric fusions (TFs). The analysis of several peo mutant combinations showed that these TFs preferentially involve the Y, XR and 4th chromosome telomeres, a TF pattern never observed in the other 10 telomere-capping mutants so far characterized. peo encodes a non-terminin protein homologous to the E2 variant ubiquitin-conjugating enzymes. The Peo protein directly interacts with the terminin components, but peo mutations do not affect telomeric localization of HOAP, Moi, Ver and HP1a, suggesting that the peo-dependent telomere fusion phenotype is not due to loss of terminin from chromosome ends. peo mutants are also defective in DNA replication and PCNA recruitment. However, our results suggest that general defects in DNA replication are unable to induce TFs in Drosophila cells. We thus hypothesize that DNA replication in Peo-depleted cells results in specific fusigenic lesions concentrated in heterochromatin-associated telomeres. Alternatively, it is possible that Peo plays a dual function being independently required for DNA replication and telomere capping. PMID:26110638

  7. Active pancreatic digestive enzymes show striking differences in their potential to damage isolated rat pancreatic acinar cells.

    PubMed

    Niederau, C; Fronhoffs, K; Klonowski, H; Schulz, H U

    1995-02-01

    Active digestive enzymes are involved in the pathophysiology of acute pancreatitis. Previous studies have mainly focused on the role of trypsin in the autodigestive process. The present study compares the noxious potential of different pancreatic enzymes to damage acinar cells. Acinar cells were isolated from rat pancreas by collagenase digestion. Cell viability was studied by (1) exclusion of trypan blue, (2) release of lactate dehydrogenase, and (3) release of newly synthesized proteins identified with methionine labeled with sulfur 35. Cells were then incubated in oxygenated N-2-hydroxyethylpiperazine-N-'-2-ethanesulfonic acid-Ringer solution containing different concentrations of various active digestive enzymes. Uptake of trypan blue was the most sensitive and reliable test of cell damage when compared with release of lactate dehydrogenase or radiolabeled newly synthesized proteins. All active digestive enzymes studied caused dose-dependent cell damage. The noxious potential, however, was strikingly different for the various enzymes. Pancreatic elastase in nanomolar concentrations caused marked cell damage after 45 to 90 minutes of incubation. Lipase and chymotrypsin caused a similar damage only at micromolar concentrations, whereas even millimolar concentrations of trypsin failed to cause significant damage. The present results confirmed recent work showing that lipase and phospholipase A2 probably cause cell damage through release of free fatty acids and lysolecithin. Although activation of trypsin might be the trigger to start the activation cascade in acute pancreatitis, trypsin itself is markedly less noxious to acinar cells when compared with other digestive enzymes. Elastase by far had the greatest noxious potential of all enzymes evaluated. Studies analyzing therapeutic effects of protease inhibitors should evaluate not only the inhibitory potential against trypsin but also that against other digestive enzymes, particularly elastase. PMID:7844475

  8. The High-latitude Electric Potential Disparity and Hemispheric Differences in the Upper Thermospheric Neutral Wind Circulation

    NASA Astrophysics Data System (ADS)

    Foerster, M.; Haaland, S.; Cnossen, I.

    2014-12-01

    We present statistical studies of both the high-latitude ionospheric potential pattern deduced from long-term observations of the Cluster Electron Drift Instrument (EDI) and upper thermospheric neutral wind circulation patterns in the Northern (NH) and Southern Hemisphere (SH) obtained from accelerometers on board of low-Earth orbiting satellites like CHAMP during about the same time interval. The cross-polar cap potential difference during southward IMF conditions appears to be on average slightly (~7%) larger in the SH compared with the NH, while the neutral wind magnitude and vorticity amplitude are mostly larger in the NH than in the SH, especially during high solar activity conditions. We attribute such behaviour to peculiarities of the hemispheres due to the non-dipolar portions of Earth's main magnetic field that constitute substantial differences between the geomagnetic field configurations of both hemispheres. They cause in particular different magnetic field flux densities in the opposite polar regions and different offsets of the invariant poles with respect to the rotation axis of the Earth. The pole is presently displaced almost twice the distance in the SH compared to the NH, which has substantial implications for the coupled magnetosphere-ionosphere-thermosphere system under the influence of external drivers. To analyse this behaviour, we have run several numerical simulations using the first-principle Coupled Magnetosphere-Ionosphere-Thermosphere (CMIT) model under various seasonal conditions. The survey of both the numerical simulation results and the observations confirm prominent asymmetries between the two hemispheres for these parameters.

  9. Relative stability of different DNA guanine quadruplex stem topologies derived using large-scale quantum-chemical computations.

    PubMed

    Šponer, Ji?í; Mládek, Arnošt; Špa?ková, Na?a; Cang, Xiaohui; Cheatham, Thomas E; Grimme, Stefan

    2013-07-01

    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, seven different folds of the cation-stabilized two-quartet G-DNA stem, each having more than 250 atoms. The solvent effects are approximated by COSMO continuum solvent. We reveal sizable 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 the quality of calculations currently relying exclusively on force fields. PMID:23742743

  10. Modeling of region-specific fMRI BOLD neurovascular response functions in rat brain reveals residual differences that correlate with the differences in regional evoked potentials

    PubMed Central

    Pawela, Christopher P.; Hudetz, Anthony G.; Ward, B. Douglas; Schulte, Marie L.; Li, Rupeng; Kao, Dennis S.; Mauck, Matthew C.; Cho, Younghoon R.; Neitz, Jay; Hyde, James S.

    2008-01-01

    The response of the rat visual system to flashes of blue light has been studied by blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI). The BOLD temporal response is dependent on the number of flashes presented and demonstrates a refractory period that depends on flash frequency. Activated brain regions included the primary and secondary visual cortex, superior colliculus (SC), dorsal Lateral Geniculate (DLG), and Lateral Posterior Nucleus (LP), which were found to exhibit differing temporal responses. To explain these differences, the BOLD neurovascular response function was modeled. A second order differential equation was developed and solved numerically to arrive at region-specific response functions. Included in the model are the light input from the diode (duty cycle), a refractory period, a transient response following onset and cessation of stimulus, and a slow adjustment to changes in the average level of the signal. Constants in the differential equation were evaluated for each region by fitting the model to the experimental BOLD response from a single flash, and the equation was then solved for multiple flashes. The simulation mimics the major features of the data; however, remaining differences in the frequency dependence of the response between the cortical and subcortical regions were unexplained. We hypothesized that these discrepancies were due to regional-specific differences in neuronal response to flash frequency. To test this hypothesis, cortical visual evoked potentials (VEPs) were recorded using the same stimulation protocol as the fMRI. Cortical VEPs were more suppressed than subcortical VEPs as flash frequency increased, supporting our hypothesis. This is the first report that regional differences in neuronal activation to the same stimulus lead to differential BOLD activation. PMID:18406628

  11. Estimation of the electric plasma membrane potential difference in yeast with fluorescent dyes: comparative study of methods.

    PubMed

    Peña, Antonio; Sánchez, Norma Silvia; Calahorra, Martha

    2010-10-01

    Different methods to estimate the plasma membrane potential difference (PMP) of yeast cells with fluorescent monitors were compared. The validity of the methods was tested by the fluorescence difference with or without glucose, and its decrease by the addition of 10 mM KCl. Low CaCl? concentrations avoid binding of the dye to the cell surface, and low CCCP concentrations avoid its accumulation by mitochondria. Lower concentrations of Ba²+ produce a similar effect as Ca²+, without producing the fluorescence changes derived from its transport. Fluorescence changes without considering binding of the dyes to the cells and accumulation by mitochondria are overshadowed by their distribution between this organelle and the cytoplasm. Other factors, such as yeast starvation, dye used, parameters of the fluorescence changes, as well as buffers and incubation times were analyzed. An additional approach to measure the actual or relative values of PMP, determining the accumulation of the dye, is presented. PMID:21063758

  12. A comparative study of nitrogen physisorption on different C70 crystal structures using an ab initio based potential.

    PubMed

    Arora, Gaurav; Klauda, Jeffery B; Sandler, Stanley I

    2005-09-15

    Quantum mechanical calculations are performed using the recently developed hybrid method for interaction energies to determine atom site Lennard-Jones potential parameters for the interactions of molecular nitrogen with C(70) molecules. This ab initio based potential is used in grand canonical Monte Carlo simulations to predict surface adsorption properties of N(2) on five known C(70) structures: rhombohedral, fcc, ideal hcp, deformed hcp, and monoclinic crystals. Because of the presence of five-membered carbon rings and the surface curvature of C(70) molecule, the Lennard-Jones potential parameters for nitrogen-carbon interactions obtained from ab initio based calculations are found to be different from that with planar graphite. The simulation results obtained from these two sets of force fields are compared and shown to differ, particularly at low coverage, where the nitrogen-carbon interactions are more important than the nitrogen-nitrogen interactions. The surface area, monolayer capacity, and isosteric heat of adsorption are calculated for various C(70) crystals and found to change appreciably as a result of the shear-induced phase transformation from hcp to rhombohedral lattice. PMID:16853204

  13. Plant Growth Promotion Potential Is Equally Represented in Diverse Grapevine Root-Associated Bacterial Communities from Different Biopedoclimatic Environments

    PubMed Central

    Fusi, Marco; Cherif, Ameur; Abou-Hadid, Ayman; El-Bahairy, Usama; Sorlini, Claudia; Daffonchio, Daniele

    2013-01-01

    Plant-associated bacteria provide important services to host plants. Environmental factors such as cultivar type and pedoclimatic conditions contribute to shape their diversity. However, whether these environmental factors may influence the plant growth promoting (PGP) potential of the root-associated bacteria is not widely understood. To address this issue, the diversity and PGP potential of the bacterial assemblage associated with the grapevine root system of different cultivars in three Mediterranean environments along a macrotransect identifying an aridity gradient were assessed by culture-dependent and independent approaches. According to 16S rRNA gene PCR-DGGE, the structure of endosphere and rhizosphere bacterial communities was highly diverse (P = 0.03) and was associated with a cultivar/latitudinal/climatic effect. Despite being diverse, the bacterial communities associated with Egyptian grapevines shared a higher similarity with the Tunisian grapevines than those cultivated in North Italy. A similar distribution, according to the cultivar/latitude/aridity gradients, was observed for the cultivable bacteria. Many isolates (23%) presented in vitro multiple stress resistance capabilities and PGP activities, the most frequent being auxin synthesis (82%), insoluble phosphate solubilisation (61%), and ammonia production (70%). The comparable numbers and types of potential PGP traits among the three different environmental settings indicate a strong functional homeostasis of beneficial bacteria associated with grape root. PMID:23878810

  14. Differences in surface marker expression and chondrogenic potential among various tissue-derived mesenchymal cells from elderly patients with osteoarthritis.

    PubMed

    Alegre-Aguarón, Elena; Desportes, Paula; García-Álvarez, Felícito; Castiella, Tomás; Larrad, Luis; Martínez-Lorenzo, María José

    2012-01-01

    Mesenchymal stem cells (MSCs) are self-renewing, multipotent cells that could potentially be used to repair injured cartilage in diseases such as osteoarthritis (OA). In this study we used bone marrow, adipose tissue from articular and subcutaneous locations, and synovial fluid samples from 18 patients with knee OA to find a suitable alternative source for the isolation of MSCs with high chondrogenic potential. MSCs from all tissues analysed had a fibroblastic morphology, but their rates of proliferation varied. Subcutaneous fat-derived MSCs proliferated faster than bone marrow- and Hoffa's fat pad-derived MSCs, while synovial fluid-derived MSCs grew more slowly. CD36 and CD54 expression was similar across all groups of MSCs with several minor differences. High expression of these surface markers in subcutaneous fat-derived MSCs was correlated with poor differentiation into hyaline cartilage. Synovial fluid-derived MSCs presented a relatively small chondrogenic differentiation capacity while Hoffa's fat pad-derived MSCs had strong chondrogenic potential. In conclusion, MSCs from elderly patients with OA may still display significant chondrogenic potential, depending on their origin. PMID:22947769

  15. 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.

  16. 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.

  17. Evaluation of Potential Sex Differences in the Subjective and Analgesic Effects of Morphine in Normal, Healthy Volunteers

    PubMed Central

    Comer, Sandra D; Cooper, Ziva D; Kowalczyk, William J; Sullivan, Maria A; Evans, Suzette M; Bisaga, Adam M; Vosburg, Suzanne K

    2012-01-01

    Rationale Sex differences in the analgesic effects of mu-opioid agonists have been documented extensively in rodents and, to a lesser extent, in non-human primates. To date, there have been few experimental studies investigating this effect in humans, and the conclusions have been equivocal. Objectives The aims of the present study were to examine potential sex differences in the analgesic, subjective, performance, and physiological effects of morphine in human research volunteers. Methods Using a double-blind outpatient procedure, the present study investigated the effects of intramuscular morphine (0, 5, and 10 mg/70 kg, i.m.) in men (N=8) and women (N=10). The primary dependent measure was analgesia, as assessed by the cold-pressor and mechanical-pressure tests. Secondary dependent measures included subjective, performance, and physiological effects of morphine, as well as plasma levels of morphine. Results No differences in the analgesic and performance effects of morphine were observed between men and women, but significant differences in morphine’s subjective effects were found. Specifically, men reported greater positive effects whereas women reported greater negative effects after morphine administration. Conclusions These data suggest that in humans, there are sex differences in the subjective mood altering effects of morphine but, based on this limited sample, there is little evidence for sex differences in its analgesic effects. PMID:19859698

  18. Detection of more than 50 different CFTR mutations in a large group of German cystic fibrosis patients.

    PubMed

    Dörk, T; Mekus, F; Schmidt, K; Bosshammer, J; Fislage, R; Heuer, T; Dziadek, V; Neumann, T; Kälin, N; Wulbrand, U

    1994-11-01

    We have conducted a comprehensive study of the molecular basis of cystic fibrosis (CF) in 350 German CF patients. A screening approach based on single-strand conformation analysis and direct sequencing of genomic polymerase chain reaction products has allowed us to detect the molecular defects on 95.4% of the CF chromosomes within the coding region and splice sites of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The spectrum of sequence changes comprises 54 different mutations, including 17 missense mutations, 14 nonsense mutations, 11 frameshift mutations, 10 splice site variants and two amino acid deletions. Eleven of these mutations have not previously been described. Our results reflect the marked mutational heterogeneity of CF in a large sample of patients from a non-isolated population. PMID:7525450

  19. A novel DAX-1 mutation presented with precocious puberty and hypogonadotropic hypogonadism in different members of a large pedigree.

    PubMed

    Durmaz, Erdem; Turkkahraman, Doga; Berdeli, Afig; Atan, Merve; Karaguzel, Gulay; Akcurin, Sema; Bircan, Iffet

    2013-01-01

    Patients with DAX-1 gene mutations on chromosome Xp21 usually present with adrenal hypoplasia congenita and hypogonadotropic hypogonadism. Yet, neither correlation between the type of mutation and the age of onset of the disease nor mechanism of the mutation on puberty is fully understood. Here, we report a novel non-sense p.Gln208X mutation in the amino terminal domain of the DAX-1 gene observed in a large family with three boys presenting with adrenal manifestations at different ages. Furthermore, two boys developed spontaneous puberty that failed to progress at similar ages, whereas the other boy developed precocious puberty at 10 month of age. The unique structure of the DAX-1 gene may explain this phenotypic variability. However, more studies are needed to understand the role of the DAX-1 gene on development of the adrenal gland and hypothalamus-pituitary-gonadal axis. PMID:23585174

  20. Exploiting large non-isomorphous differences for phase determination of a G-segment invertase–DNA complex

    PubMed Central

    Ritacco, Christopher J.; Steitz, Thomas A.; Wang, Jimin

    2014-01-01

    Crystals of the G-segment invertase in complex with a 37-base-pair asymmetric DNA duplex substrate had an unusually high solvent content of 88% and diffracted to a maximal resolution of about 5.0?Å. These crystals exhibited a high degree of non-isomorphism and anisotropy, which presented a serious challenge for structure determination by isomorphous replacement. Here, a procedure of cross-crystal averaging is described that uses large non-isomorphous crystallographic data with a priori information of an approximate molecular boundary as determined from a minimal amount of experimental phase information. Using this procedure, high-quality experimental phases were obtained that have enabled it to be shown that the conformation of the bound substrate DNA duplex significantly differs from those of substrates bound in other serine recombinase–DNA complexes. PMID:24598738

  1. Job Stress in the United Kingdom: Are Small and Medium-Sized Enterprises and Large Enterprises Different?

    PubMed

    Lai, Yanqing; Saridakis, George; Blackburn, Robert

    2013-12-01

    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. Copyright © 2013 John Wiley & Sons, Ltd. PMID:24302431

  2. Neurite, a finite difference large scale parallel program for the simulation of electrical signal propagation in neurites under mechanical loading.

    PubMed

    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

  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. 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. Anat Rec, 298:1367-1375, 2015. © 2015 Wiley Periodicals, Inc. PMID:25884664

  5. A large population of king crabs in Palmer Deep on the west Antarctic Peninsula shelf and potential invasive impacts.

    PubMed

    Smith, Craig R; Grange, Laura J; Honig, David L; Naudts, Lieven; Huber, Bruce; Guidi, Lionel; Domack, Eugene

    2012-03-01

    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 × 10(6) 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 1.4°C in Palmer Deep, and was not found in extensive surveys of the colder shelf at depths of 430-725 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 0.01°C yr(-1); if N. yaldwyni is currently limited by cold temperatures, it could spread up onto the shelf (400-600 m depths) within 1-2 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

  6. Different neural substrates underlying directed forgetting for negative and neutral images: an event-related potential study.

    PubMed

    Yang, Wenjing; Liu, Peiduo; Xiao, Xiao; Li, Xueping; Zeng, Can; Qiu, Jiang; Zhang, Qinglin

    2012-03-01

    The aim of this study was to investigate the different neural correlations of directed forgetting for emotionally negative and neutral images in 17 healthy individuals using event-related potentials (ERPs). Behavioral findings showed that the task yielded a robust directed forgetting effect for both neutral and negative images: more to-be-remembered than to-be-forgotten images were recognized. ERPs were recorded as participants viewed different valence images (negative/neutral) and were given different instructions, including remember (R) or forget (F) commands. Enhanced late parietal positive potentials were observed for negative images during image viewing. In the 200-300 ms time window, F instructions elicited a larger N2 than did R instructions and successful implementation of F instructions (F-miss) appeared more negative over the frontal region comparing with the unintentional forgetting (R-miss), suggesting that F instructions trigger a frontal mechanism to inhibit the processing of previously presented images. More important, F instructions following emotionally negative images elicited an enhanced frontal N2 effect than neutral images. This result suggests that forgetting negative stimuli is more laborious. In addition, within the 300-400 ms time window, R instructions elicited a larger P3 response than did F instructions and successful implementation of the R instructions (R-hit) appeared more positive than the unintentional remembering (F-hit) over the posterior scalp region. This posterior wave might reflect rehearsal and memory consolidation process. PMID:22285435

  7. Effects of baseline levels of flexibility and vertical jump ability on performance following different volumes of static stretching and potentiating exercises in elite gymnasts.

    PubMed

    Donti, Olyvia; Tsolakis, Charilaos; Bogdanis, Gregory C

    2014-01-01

    This study examined the effects of baseline flexibility and vertical jump ability on straight leg raise range of motion (ROM) and counter-movement jump performance (CMJ) following different volumes of stretching and potentiating exercises. ROM and CMJ were measured after two different warm-up protocols involving static stretching and potentiating exercises. Three groups of elite athletes (10 male, 14 female artistic gymnasts and 10 female rhythmic gymnasts) varying greatly in ROM and CMJ, performed two warm-up routines. One warm-up included short (15 s) static stretching followed by 5 tuck jumps, while the other included long static stretching (30 s) followed by 3x5 tuck jumps. ROM and CMJ were measured before, during and for 12 min after the two warm-up routines. Three-way ANOVA showed large differences between the three groups in baseline ROM and CMJ performance. A type of warm-up x time interaction was found for both ROM (p = 0.031) and CMJ (p = 0.016). However, all athletes, irrespective of group, responded in a similar fashion to the different warm-up protocols for both ROM and CMJ, as indicated from the lack of significant interactions for group (condition x group, time x group or condition x time x group). In the short warm-up protocol, ROM was not affected by stretching, while in the long warm-up protocol ROM increased by 5.9% ± 0.7% (p = 0.001) after stretching. Similarly, CMJ remained unchanged after the short warm-up protocol, but increased by 4.6 ± 0.9% (p = 0.012) 4 min after the long warm- up protocol, despite the increased ROM. It is concluded that the initial levels of flexibility and CMJ performance do not alter the responses of elite gymnasts to warm-up protocols differing in stretching and potentiating exercise volumes. Furthermore, 3 sets of 5 tuck jumps result in a relatively large increase in CMJ performance despite an increase in flexibility in these highly-trained athletes. Key PointsThe initial levels of flexibility and vertical jump ability have no effect on straight leg raise range of motion (ROM) and counter-movement jump performance (CMJ) of elite gymnasts following warm-up protocols differing in stretching and potentiating exercise volumesStretching of the main leg muscle groups for only 15 s has no effect on ROM of elite gymnastsIn these highly-trained athletes, one set of 5 tuck jumps during warm-up is not adequate to increase CMJ performance, while 3 sets of 5 tuck jumps result in a relatively large increase in CMJ performance (by 4.6% above baseline), despite a 5.9% increase in flexibility due to the 30 s stretching exercises. PMID:24570613

  8. Differences by sex, ear, and sexual orientation in the time intervals between successive peaks in auditory evoked potentials.

    PubMed

    McFadden, Dennis; Hsieh, Michelle D; Garcia-Sierra, Adrian; Champlin, Craig A

    2010-12-01

    Auditory evoked potential (AEP) data from two studies originally designed for other purposes were reanalyzed. The auditory brainstem response (ABR), middle-latency response (MLR), and long-latency response (LLR) were measured. The latencies to each of several peaks were measured for each subject for each ear of click presentation, and the time intervals between successive peaks were calculated. Of interest were differences in interpeak intervals between the sexes, between people of differing sexual orientations, and between the two ears of stimulation. Most of the differences obtained were small. The largest sex differences were for interval I ? V in the ABR and interval N1 ? N2 of the LLR (effect sizes > 0.6). The largest differences between heterosexuals and nonheterosexuals were for the latency to Wave I in both sexes, for the interval Na ? Nb in females, and for intervals V ? Na and Nb ? N1 in males (effect sizes > 0.3). The largest difference for ear stimulated was for interval N1 ? N2 in heterosexual females (effect size ?0.5). No substantial differences were found in the AEP intervals between women using, and not using, oral contraceptives. Left/right correlations for the interpeak intervals were mostly between about 0.4 and 0.6. Correlations between the ipsilateral intervals were small; i.e., interval length early in the AEP series was not highly predictive of interval length later in the series. Interpeak intervals appear generally less informative than raw latencies about differences by sex and by sexual orientation. PMID:20875848

  9. Different sensitivity of germinal center B cell-like diffuse large B cell lymphoma cells towards ibrutinib treatment

    PubMed Central

    2014-01-01

    Background Although rituximab in the combination of CHOP chemotherapy has been widely used as the standard treatment for several kinds of B-cell non-Hodgkin lymphoma (B-NHL), a great number of B-NHL patients treated with this immunotherapy still develop primary and secondary resistance. Recently Bruton’s tyrosine kinase (Btk) inhibitor ibrutinib showed promising therapeutic effect in relapsed/refractory CLL and B-cell NHL, which provided essential alternatives for these patients. Methods The proliferation and apoptosis induction of tumor cells were measured by cell viability assay and Annexin-V staining. Western Blotting analysis and real-time PCR were used to detect the expression level of target proteins and chemokines production. Results We demonstrated that ibrutinib inhibited the proliferation and induced apoptosis of GCB-DLBCL cell lines through suppression of BCR signaling pathway and activation of caspase-3. Furthermore, the chemokines CCL3 and CCL4 production from tumor cells were also found to be attenuated by ibrutinib treatment. But different cell lines exhibited distinct sensitivity after ibrutinib treatment. Interestingly, the decreasing level of p-ERK after ibrutinib treatment, but not the basal expression level of Btk, correlated with different drug sensitivity. Conclusions Ibrutinib could be a potentially useful therapy for GCB-DLBCL and the decreasing level of p-ERK could become a useful biomarker to predict related therapeutic response. PMID:24693884

  10. The generalized spin-boson model for electron-transfer reactions involving two harmonic potentials with a different force constant

    SciTech Connect

    Tang, J.

    1994-01-01

    The generalized spin-model is employed to analyze the electron-transfer reactions involving two harmonic potentials with a different force constant. An analytical expression for the nonadiabatic rate constant is derived with fill consideration of the effects of quantum modes. For a single dominant solvent mode at low frequency, the result of the high temperature regime is reduced to the formula derived earlier based on the stochastic Liouville theory. For multiple soft solvent modes, the rate constant is a convoluted integral of a rate function for each individual single mode.

  11. Use of different organic wastes in reducing the potential leaching of propanil, isoxaben, cadusafos and pencycuron through the soil.

    PubMed

    Fenoll, José; Garrido, Isabel; Hellín, Pilar; Flores, Pilar; Vela, Nuria; Navarro, Simón

    2014-01-01

    In this study, we examined the effect of four different organic wastes (OW)-composted sheep manure (CSM), spent coffee grounds (SCG), composted pine bark (CPB) and coir (CR)-on the potential groundwater pollution of propanil and isoxaben (herbicides), cadusafos (insecticide) and pencycuron (fungicide) under laboratory conditions. For this purpose, leaching studies were conducted using disturbed soil columns filled with a clay loam soil (Hipercalcic calcisol). The addition of organic matter (OM) drastically reduced the movement of the studied pesticides. The results obtained point to the interest in the use of agro-industrial and composted OW in reducing the groundwater pollution by pesticide drainage. PMID:24901963

  12. [Iron and zinc in vitro potential availability in an infant diet with fortified bread with different iron sources or with the addition of different iron absorption promoters].

    PubMed

    Binaghi, María J; Cagnasso, Carolina E; Pellegrino, Nestor R; Drago, Silvina R; González, Rolando; Ronayne, Patricia A; Valencia, Mirta E

    2011-09-01

    Home-made diets are the most frequently used complementary foods. In the present work we evaluated iron and zinc availability in a usually consumed infant diet containing either iron-fortified bread with different iron sources: ferrous sulfate, ferrous bisglycinate, NaFeEDTA. We also used non-fortified bread with absorption promoters: ascorbic acid, sodium citrate, Na2EDTA, combined with different beverages. The diet (potato, pumpkin, grits, bread, and apple) was combined with water, milk, tea, a soft drink and an orange-based artificial drink. Mineral dialyzability (D) as an indicator of potential availability was determined using an in vitro method. Statistical analysis was performed by ANOVA, and a posteriori Tukey test. There were no significant differences in FeD between diets with ferrous sulfate or ferrous bisglycinate fortified bread; in NaFeEDTA fortified bread it increased significantly (p<0.05). Iron D increase was greater in diets with bread containing absorption promoters than in those with fortified bread. The orange-based artificial drink increased FeD, while tea and milk decreased it significantly (p < 0.05). Zinc D increased significantly when the bread was fortified either with ferrous sulfate or NaFeEDTA, but remained unchanged in diets with ferrous bisglycinate fortified bread. The addition of tea or milk decreased ZnD while the orange-based artificial drink increased it significantly (p < 0.05). Regarding absorption promoters, the greater values both in FeD and ZnD were observed in diets with iron nonfortified bread containing Na2EDTA. PMID:22696901

  13. [Evoked potentials of the cat inferior colliculus to acoustic stimuli simulating sound source movement with different velocities in opposite directions].

    PubMed

    Bekhterev, N N

    2003-06-01

    Amplitude changes of inferior colliculus evoked potentials (EPs) in anaesthetized adult cats were studied under presentation of acoustic stimuli simulating both azimuth-moving and stationary sound source. The movement was simulated with gradual changes of interaural time delay between binaurally presented click trains. It was shown that the amplitude of EPs elicited by "moving" signals depended on the velocity of movement. Amplitude differences between EPs to "moving" and stationary stimuli were observed under motion velocities up to 320 deg./s. The greatest response amplitudes in different experiments took place under velocities within the range of 67-320 deg./s with most of them recorded under velocities of 170 and 125 deg./s. Amplitude of the responses to lateral-medial movement with any velocity were always greater than those to opposite direction of movement with the same velocity. PMID:12966705

  14. Different patterns of local field potentials from limbic DBS targets in patients with major depressive and obsessive compulsive disorder.

    PubMed

    Neumann, W-J; Huebl, J; Brücke, C; Gabriëls, L; Bajbouj, M; Merkl, A; Schneider, G-H; Nuttin, B; Brown, P; Kühn, A A

    2014-11-01

    The role of distinct limbic areas in emotion regulation has been largely inferred from neuroimaging studies. Recently, the opportunity for intracranial recordings from limbic areas has arisen in patients undergoing deep brain stimulation (DBS) for neuropsychiatric disorders including major depressive disorder (MDD) and obsessive compulsive disorder (OCD). Here we test the hypothesis that distinct temporal patterns of local field potential (LFP) activity in the human limbic system reflect disease state and symptom severity in MDD and OCD patients. To this end, we recorded LFPs via implanted DBS electrodes from the bed nucleus of stria terminalis (BNST area) in 12 patients (5 OCD, 7 MDD) and from the subgenual cingulate cortex in 7 MDD patients (CG25 area). We found a distinct pattern of oscillatory activity with significantly higher ?-power in MDD compared with OCD in the BNST area (broad ?-band 8-14?Hz; P<0.01) and a similar level of ?-activity in the CG25 area as in the BNST area in MDD patients. The mean ?-power correlated with severity of depressive symptoms as assessed by the Beck depression inventory in MDD (n=14, r=0.55, P=0.042) but not with severity of obsessive compulsive symptoms in OCD. Here we show larger ?-band activity in MDD patients compared with OCD recorded from intracranial DBS targets. Our results suggest that ?-activity in the limbic system may be a signature of symptom severity in MDD and may serve as a potential state biomarker for closed loop DBS in MDD. PMID:24514569

  15. Antioxidant supplementation in vitro improves boar sperm motility and mitochondrial membrane potential after cryopreservation of different fractions of the ejaculate.

    PubMed

    Peña, F J; Johannisson, A; Wallgren, M; Rodriguez Martinez, H

    2003-09-15

    Antioxidant supplementation during cooling was assayed to improve the motility of frozen-thawed (FT) boar spermatozoa from two different fractions of the ejaculate, the first component of the sperm-rich fraction (Fraction I) and the rest of the bulk ejaculate (Fraction II). Using a split-sample design, addition of two different concentrations (100 and 200 microMl(-1)) of the water-soluble Vitamin E analogue Trolox (6-hydroxy -2,5,7,8-tetramethylchroman -2-carboxylic acid) was evaluated for an effect on sperm motility (measured both subjectively and by means of a computer assisted motility assessment (CASA)), and on mitochondrial membrane potential using flow cytometry after cell-loading with JC-1. The effect of the Vitamin E analogue was clearly dose-dependent and varied with the fraction of the ejaculate considered. Motility was significantly higher in Trolox-treated spermatozoa (200 microm), from either ejaculate fraction, albeit the effect was more evident in spermatozoa from Fraction II (P<0.05) for any Trolox-concentration. Antioxidant supplementation resulted, also dose-dependent, in a higher number of spermatozoa showing high mitochondrial activity as assessed by the JC-1 staining, in both ejaculate fractions. In the present trial, exogenous Trolox positively affected post-thaw sperm viability (as motility and mitochondrial membrane potential) in both fractions of the ejaculate. The magnitude of the effect appeared, however, to be dependent of the fraction of the ejaculate considered. PMID:12753785

  16. Phylogeographic Structure in Benthic Marine Invertebrates of the Southeast Pacific Coast of Chile with Differing Dispersal Potential

    PubMed Central

    Haye, Pilar A.; Segovia, Nicolás I.; Muñoz-Herrera, Natalia C.; Gálvez, Francisca E.; Martínez, Andrea; Meynard, Andrés; Pardo-Gandarillas, María C.; Poulin, Elie; Faugeron, Sylvain

    2014-01-01

    The role of dispersal potential on phylogeographic structure, evidenced by the degree of genetic structure and the presence of coincident genetic and biogeographic breaks, was evaluated in a macrogeographic comparative approach along the north-central coast of Chile, across the biogeographic transition zone at 30°S. Using 2,217 partial sequences of the mitochondrial Cytochrome Oxidase I gene of eight benthic invertebrate species along ca. 2,600 km of coast, we contrasted dispersal potential with genetic structure and determined the concordance between genetic divergence between biogeographic regions and the biogeographic transition zone at 30°S. Genetic diversity and differentiation highly differed between species with high and low dispersal potential. Dispersal potential, sometimes together with biogeographic region, was the factor that best explained the genetic structure of the eight species. The three low dispersal species, and one species assigned to the high dispersal category, had a phylogeographic discontinuity coincident with the biogeographic transition zone at 30°S. Furthermore, coalescent analyses based on the isolation-with-migration model validate that the split between biogeographic regions north and south of 30°S has a historic origin. The signatures of the historic break in high dispersers is parsimoniously explained by the homogenizing effects of gene flow that have erased the genetic signatures, if ever existed, in high dispersers. Of the four species with structure across the break, only two had significant albeit very low levels of asymmetric migration across the transition zone. Historic processes have led to the current biogeographic and phylogeographic structure of marine species with limited dispersal along the north-central coast of Chile, with a strong lasting impact in their genetic structure. PMID:24586356

  17. 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.

  18. Finite-difference modeling of borehole induction data in the presence of 3D electrical conductivity anisotropy using coupled scattered potentials

    E-print Network

    Torres-Verdín, Carlos

    ). The potential formulation is becoming a popular numerical technique for FD modeling of EM fields in complex numerical examples considered in the benchmark study indicate that the scattered potential FD method and numerical experiments show that the potential finite-difference (FD) formulation has obvious advantages over

  19. A Different View on the Checkerboard? Alterations in Early and Late Visually Evoked EEG Potentials in Asperger Observers

    PubMed Central

    Kornmeier, Juergen; Wörner, Rike; Riedel, Andreas; Bach, Michael; Tebartz van Elst, Ludger

    2014-01-01

    Background Asperger Autism is a lifelong psychiatric condition with highly circumscribed interests and routines, problems in social cognition, verbal and nonverbal communication, and also perceptual abnormalities with sensory hypersensitivity. To objectify both lower-level visual and cognitive alterations we looked for differences in visual event-related potentials (EEG) between Asperger observers and matched controls while they observed simple checkerboard stimuli. Methods In a balanced oddball paradigm checkerboards of two checksizes (0.6° and 1.2°) were presented with different frequencies. Participants counted the occurrence times of the rare fine or rare coarse checkerboards in different experimental conditions. We focused on early visual ERP differences as a function of checkerboard size and the classical P3b ERP component as an indicator of cognitive processing. Results We found an early (100–200 ms after stimulus onset) occipital ERP effect of checkerboard size (dominant spatial frequency). This effect was weaker in the Asperger than in the control observers. Further a typical parietal/central oddball-P3b occurred at 500 ms with the rare checkerboards. The P3b showed a right-hemispheric lateralization, which was more prominent in Asperger than in control observers. Discussion The difference in the early occipital ERP effect between the two groups may be a physiological marker of differences in the processing of small visual details in Asperger observers compared to normal controls. The stronger lateralization of the P3b in Asperger observers may indicate a stronger involvement of the right-hemispheric network of bottom-up attention. The lateralization of the P3b signal might be a compensatory consequence of the compromised early checksize effect. Higher-level analytical information processing units may need to compensate for difficulties in low-level signal analysis. PMID:24632708

  20. Mechanisms Underlying Fictive Feeding in Aplysia: Coupling Between a Large Neuron With Plateau Potentials Activity and a

    E-print Network

    Byrne, John H.

    of the model were examined. In one configuration, a fast excitatory postsynaptic potential (EPSP) from B63 to B EPSPs in B31/B32 and the plateau-like potential was removed from B31/B32. Simulations indi- cated was initiated, the circuit produced the program in an all-or-none fashion. The slow kinetics of the simulated

  1. Large self-diffusion of water on brucite surface by ab initio potential energy surface and molecular dynamics simulations

    Microsoft Academic Search

    Hiroshi Sakuma; Taku Tsuchiya; Katsuyuki Kawamura; Kenshiro Otsuki

    2003-01-01

    Mobility of water at the (0001) surfaces of brucite has been studied using a molecular dynamics method. Ab initio model potential for the water–brucite interaction has been obtained by fitting the parameters to ab initio electronic structure data, calculated by means of the first-principles method based on density functional theory. Using this ab initio model potential, molecular dynamics simulations of

  2. The Drosophila insulin receptor homolog: a gene essential for embryonic development encodes two receptor isoforms with different signaling potential.

    PubMed Central

    Fernandez, R; Tabarini, D; Azpiazu, N; Frasch, M; Schlessinger, J

    1995-01-01

    We report the cloning and primary structure of the Drosophila insulin receptor gene (inr), functional expression of the predicted polypeptide, and the isolation of mutations in the inr locus. Our data indicate that the structure and processing of the Drosophila insulin proreceptor are somewhat different from those of the mammalian insulin and IGF 1 receptor precursors. The INR proreceptor (M(r) 280 kDa) is processed proteolytically to generate an insulin-binding alpha subunit (M(r) 120 kDa) and a beta subunit (M(r) 170 kDa) with protein tyrosine kinase domain. The INR beta 170 subunit contains a novel domain at the carboxyterminal side of the tyrosine kinase, in the form of a 60 kDa extension which contains multiple potential tyrosine autophosphorylation sites. This 60 kDa C-terminal domain undergoes cell-specific proteolytic cleavage which leads to the generation of a total of four polypeptides (alpha 120, beta 170, beta 90 and a free 60 kDa C-terminus) from the inr gene. These subunits assemble into mature INR receptors with the structures alpha 2(beta 170)2 or alpha 2(beta 90)2. Mammalian insulin stimulates tyrosine phosphorylation of both types of beta subunits, which in turn allows the beta 170, but not the beta 90 subunit, to bind directly to p85 SH2 domains of PI-3 kinase. It is likely that the two different isoforms of INR have different signaling potentials. Finally, we show that loss of function mutations in the inr gene, induced by either a P-element insertion occurring within the predicted ORF, or by ethylmethane sulfonate treatment, render pleiotropic recessive phenotypes that lead to embryonic lethality. The activity of inr appears to be required in the embryonic epidermis and nervous system among others, since development of the cuticle, as well as the peripheral and central nervous systems are affected by inr mutations. Images PMID:7628438

  3. Do Drug Treatment Facilities Increase Clients’ Exposure to Potential Neighborhood-Level Triggers for Relapse? A Small-Area Assessment of a Large, Public Treatment System

    PubMed Central

    2006-01-01

    Research on drug treatment facility locations has focused narrowly on the issue of geographic proximity to clients. We argue that neighborhood conditions should also enter into the facility location decision and illustrate a formal assessment of neighborhood conditions at facilities in a large, metropolitan area, taking into account conditions clients already face at home. We discuss choice and construction of small-area measures relevant to the drug treatment context, including drug activity, disadvantage, and violence as well as statistical comparisons of clients’ home and treatment locations with respect to these measures. Analysis of 22,707 clients discharged from 494 community-based outpatient and residential treatment facilities that received public funds during 1998–2000 in Los Angeles County revealed no significant mean differences between home and treatment neighborhoods. However, up to 20% of clients are exposed to markedly higher levels of disadvantage, violence, or drug activity where they attend treatment than where they live, suggesting that it is not uncommon for treatment locations to increase clients’ exposure to potential environmental triggers for relapse. Whereas on average both home and treatment locations exhibit higher levels of these measures than the household locations of the general population, substantial variability in public treatment clients’ home neighborhoods calls into question the notion that they hail exclusively from poor, high drug activity areas. Shortcomings of measures available for neighborhood assessment of treatment locations and implications of the findings for other areas of treatment research are also discussed. PMID:16736365

  4. Exploiting the potential of large databases of electronic health records for research using rapid search algorithms and an intuitive query interface

    PubMed Central

    Tate, A Rosemary; Beloff, Natalia; Al-Radwan, Balques; Wickson, Joss; Puri, Shivani; Williams, Timothy; Van Staa, Tjeerd; Bleach, Adrian

    2014-01-01

    Objective UK primary care databases, which contain diagnostic, demographic and prescribing information for millions of patients geographically representative of the UK, represent a significant resource for health services and clinical research. They can be used to identify patients with a specified disease or condition (phenotyping) and to investigate patterns of diagnosis and symptoms. Currently, extracting such information manually is time-consuming and requires considerable expertise. In order to exploit more fully the potential of these large and complex databases, our interdisciplinary team developed generic methods allowing access to different types of user. Materials and methods Using the Clinical Practice Research Datalink database, we have developed an online user-focused system (TrialViz), which enables users interactively to select suitable medical general practices based on two criteria: suitability of the patient base for the intended study (phenotyping) and measures of data quality. Results An end-to-end system, underpinned by an innovative search algorithm, allows the user to extract information in near real-time via an intuitive query interface and to explore this information using interactive visualization tools. A usability evaluation of this system produced positive results. Discussion We present the challenges and results in the development of TrialViz and our plans for its extension for wider applications of clinical research. Conclusions Our fast search algorithms and simple query algorithms represent a significant advance for users of clinical research databases. PMID:24272162

  5. Different biological risk factors in young poor-prognosis and elderly patients with diffuse large B-cell lymphoma.

    PubMed

    Horn, H; Ziepert, M; Wartenberg, M; Staiger, A M; Barth, T F E; Bernd, H-W; Feller, A C; Klapper, W; Stuhlmann-Laeisz, C; Hummel, M; Stein, H; Lenze, D; Hartmann, S; Hansmann, M-L; Möller, P; Cogliatti, S; Pfreundschuh, M; Trümper, L; Loeffler, M; Glass, B; Schmitz, N; Ott, G; Rosenwald, A

    2015-07-01

    Prognostically relevant risk factors in patients with diffuse large B-cell lymphoma (DLBCL) have predominantly been evaluated in elderly populations. We tested whether previously described risk factors are also valid in younger, poor-prognosis DLBCL patients. Paraffin-embedded samples from 112 patients with de novo DLBCL, enrolled in the R-MegaCHOEP trial of the German High Grade Non-Hodgkin Lymphoma Study Group (DSHNHL) were investigated using immunohistochemistry (MYC, FOXP1, LMO2, GCET1, CD5, CD10, BCL2, BCL6, IRF4/MUM1) and fluorescence in situ hybridization (MYC, BCL2, BCL6). MYC, BCL2 and BCL6 breaks occurred in 14, 21 and 31%, respectively. In the majority of cases, MYC was simultaneously rearranged with BCL2 and/or BCL6. The adverse impact of MYC rearrangements was confirmed, but the sole presence of BCL2 breaks emerged as a novel prognostic marker associated with inferior overall survival (OS) (P=0.002). Combined overexpression of MYC and BCL2 showed only limited association with inferior OS. All immunohistochemical cell of origin classifiers applied failed to predict survival time. DLBCL tumors with significant proportion of immunoblastic and/or immunoblastic-plasmacytoid cells had inferior OS, independently from from BCL2 break. Younger, poor-prognosis DLBCL patients, therefore, display different biological risk factors compared with an elderly population, with BCL2 translocations emerging as a powerful negative prognostic marker. PMID:25687653

  6. Simultaneous projection and detection system of four different frequencies for microwave imaging reflectometry in Large Helical Device

    SciTech Connect

    Yoshinaga, T.; Nagayama, Y.; Tsuchiya, H. [National Institute for Fusion Science, 322-6 Oroshi, Toki 509-5292 (Japan); Kuwahara, D.; Tsuji-Iio, S. [Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro 152-8550 (Japan); Yamaguchi, S. [Kansai University, 3-3-35 Yamate, Suita 564-8680 (Japan); Kogi, Y. [Fukuoka Institute of Technology, 3-30-1 Wajiro-Higashi, Fukuoka 811- 0295 (Japan); Mase, A. [Kyushu University, 6-1 Kasuga-Koen, Kasuga 816-8680 (Japan)

    2010-10-15

    A simultaneous projection/detection system of four different frequencies for microwave imaging reflectometry (MIR) was developed for three-dimensional observation of electron density fluctuations in the Large Helical Device (LHD). The microwave with four frequency components at 60.410, 61.808, 63.008, and 64.610 GHz is projected in a continuous-wave mode to illuminate the target LHD plasma. A two-dimensional horn-antenna mixer array (2D HMA) receives the reflected wave from the plasma as well as the wave from the local oscillator operating at 55.800 GHz. The first intermediate frequency (IF) signals at 4.610, 6.008, 7.208, and 8.810 GHz were confirmed to be obtained by downconversion of these microwaves using the 2D HMA. Each of these first IF components is filtered from each other and downconverted again for the superheterodyne detection. It was confirmed that both the amplitudes and the phases of the detected signals reflect the fluctuations in LHD plasmas.

  7. Determine the number of nitrogen vacancy color centers in the nano-diamond particles with large size difference

    NASA Astrophysics Data System (ADS)

    Hsu, Jui-Hung; Su, Long-Jyun; Chang, Huan-Cheng

    2015-03-01

    The number of emitters in a nano-particle is usually determined by the photon correlation using the Hanbury Brown and Twiss configuration. However, limited to the photon statics, this method is only valid for the small numbers. It would be difficult to measure the number of emitters, if individual nano-particles contain more than several tens or hundreds of emitters. In this contribution, we present a work to quantitatively determine the number of nitrogen-vacancy (NV) centers in the individual nano-diamond (ND) particles. Our previous work (Nanotechnology 24, 315702) suggests that the density of NV centers would be significantly decreased while reducing ND particle size from 100 nm to 30 nm. It thus motivates us to measure the number of NV centers of individual ND particles with large size difference. Under saturated the pulse excitation, the emission intensity from individual ND particle is proportional to the number of NV centers and the fluorescence quantum yield, which are able to be determined independently.

  8. Simultaneous projection and detection system of four different frequencies for microwave imaging reflectometry in Large Helical Device.

    PubMed

    Yoshinaga, T; Nagayama, Y; Kuwahara, D; Tsuchiya, H; Yamaguchi, S; Kogi, Y; Tsuji-Iio, S; Mase, A

    2010-10-01

    A simultaneous projection/detection system of four different frequencies for microwave imaging reflectometry (MIR) was developed for three-dimensional observation of electron density fluctuations in the Large Helical Device (LHD). The microwave with four frequency components at 60.410, 61.808, 63.008, and 64.610 GHz is projected in a continuous-wave mode to illuminate the target LHD plasma. A two-dimensional horn-antenna mixer array (2D HMA) receives the reflected wave from the plasma as well as the wave from the local oscillator operating at 55.800 GHz. The first intermediate frequency (IF) signals at 4.610, 6.008, 7.208, and 8.810 GHz were confirmed to be obtained by downconversion of these microwaves using the 2D HMA. Each of these first IF components is filtered from each other and downconverted again for the superheterodyne detection. It was confirmed that both the amplitudes and the phases of the detected signals reflect the fluctuations in LHD plasmas. PMID:21033947

  9. Abstract --In this paper, we describe a hierarchical architecture that can potentially scale peer-to-peer (P2P) networks to large numbers of

    E-print Network

    Chen, Sheng-Wei

    Abstract -- In this paper, we describe a hierarchical architecture that can potentially scale peer-to-peer (P2P) networks to large numbers of peer nodes and contents. Two principles are followed: network networks are network where peer nodes communicate and transport information directly with each other

  10. Evaluation of in vitro aldose reductase inhibitory potential of different fraction of Hybanthus enneaspermus Linn F. Muell

    PubMed Central

    Patel, DK; Kumar, R; Kumar, M; Sairam, K; Hemalatha, S

    2012-01-01

    Objective To evaluate the aldose reductase inhibitory (ARI) activity of different fractions of Hybanthus enneaspermus for potential use in diabetic cataract. Methods Total phenol and flavonoid content of different fractions was determined. ARI activity of different fractions in rat lens was investigated in vitro. Results The results showed significant level of phenolic and flavonoid content in ethyl acetate fraction [total phenol (212.15±0.79 mg/g), total flavonoid (39.11±2.27 mg/g)] and aqueous fraction [total phenol (140.62±0.57 mg/g), total flavonoid (26.07±1.49 mg/g)] as compared with the chloroform fraction [total phenol (68.56±0.51 mg/g), total flavonoid (13.41±0.82 mg/g)] and petrolium ether fraction [total phenol (36.68±0.43 mg/g), total flavonoid (11.55±1.06 mg/g)]. There was a significant difference in the ARI activity of each fraction, and it was found to be the highest in ethyl acetate fraction [IC50 (49.26±1.76 µg/mL)] followed by aqueous extract [IC50 (70.83±2.82 µg/mL)] and it was least in the petroleum ether fraction [IC50 (118.89±0.71 µg/mL)]. Chloroform fraction showed moderate activity [IC50 (98.52±1.80 µg/mL)]. Conclusions Different fractions showed significanct amount of ARI activity, where in ethyl acetate fraction it was found to be maximum which may be due to its high phenolic and flavonoid content. The extract after further evaluation may be used in the treatment of diabetic cataract. PMID:23569883

  11. Individual Differences in Non-verbal Number Discrimination Correlate with Event-related Potentials and Measures of Probabilistic Reasoning

    PubMed Central

    Paulsen, David J.; Woldorff, Marty G.; Brannon, Elizabeth M.

    2010-01-01

    The current study investigated the neural activity patterns associated with numerical sensitivity in adults. Event-related potentials (ERPs) were recorded while adults observed sequentially presented display arrays (S1 and S2) of non-symbolic numerical stimuli (dots) and made same/different judgments of these stimuli by pressing a button only when numerosities were the same (target trials). The main goals were to contrast the effects of numerical distance (close, medium, and far) and change direction (increasing, decreasing) between S1 and S2, both in terms of behavior and brain activity, and to examine the influence of individual differences in numeracy on the effects of these manipulations. Neural effects of distance were found to be significant between 360–600 ms after the onset of S2 (greater negativity-wave activity for closer numerical distances), while direction effects were found between 320–440ms (greater negativity for decreasing direction). ERP change-direction effects did not interact with numerical distance, suggesting that the two types of information are processed independently. Importantly, subjects’ behavioral Weber fractions (w) for the same/different discrimination task correlated with distance-related ERP-activity amplitudes. Moreover, w also correlated with a separate objective measure of mathematical ability. Results thus draw a clear link between brain and behavior measures of number discrimination, while also providing support for the relationship between non-verbal magnitude discrimination and symbolic numerical processing. PMID:20817003

  12. Geographic variations of life history traits and potential trade-offs in different populations of the parasitoid Leptopilina heterotoma

    NASA Astrophysics Data System (ADS)

    Vuarin, Pauline; Allemand, Roland; Moiroux, Joffrey; van Baaren, Joan; Gibert, Patricia

    2012-11-01

    Energy allocation is determined by resource availability and trade-offs among traits, and so organisms have to give some traits priority over others to maximize their fitness according to their environment. In this study, we investigated the geographic variations in life history traits and potential trade-offs in populations of the parasitoid Leptopilina heterotoma (Hymenoptera: Figitidae) originating from the north and the south of the Rhône-Saône valley (over a gradient of 300 km, South-East France). We measured a set of traits related to reproduction, maintenance, and mobility using several estimators of each of these main functions determined at different times. We did not find any clear differences between populations from contrasting areas, whereas the southern populations, which were all assumed to be exposed to similar environmental conditions, displayed contrasting patterns of energy allocation. Thus, the most likely explanation seems to be that the evolution of the life history of L. heterotoma is probably shaped by local selective pressures, such as microclimate, microhabitats, or intensity of competition, rather than by regional ecological conditions. Using our study as an example, we discuss the interest of considering several traits and using different ways of measuring them, concluding that multiple measurements should be performed in future studies to ensure the robustness of the results.

  13. The potential of selected macroalgal species for treatment of AMD at different pH ranges in temperate regions.

    PubMed

    Oberholster, Paul J; Cheng, Po-Hsun; Botha, Anna-Maria; Genthe, Bettina

    2014-09-01

    The metal bioaccumulation potential of selected macroalgae species at different pH ranges was study for usage as part of a possible secondary passive acid mine drainage (AMD) treatment technology in algae ponds. Two separate studies were conducted to determine the suitability of macroalgae for passive treatment when metabolic processes in macrophytes and microorganisms in constructed wetlands decrease during winter months. In the field study, the bioconcentration of metals (mg/kg dry weight) measured in the benthic macroalgae mats was in the following order: site 1. Oedogonium crassum Al > Fe > Mn > Zn; site 2. Klebsormidium klebsii, Al > Fe > Mn > Zn; site 3. Microspora tumidula, Fe > Al > Mn > Zn and site 4. M. tumidula, Fe > Mn > Al > Zn. In the laboratory study, cultured macroalgae K. klebsii, O. crassum and M. tumidula isolated from the field sampling sites were exposed to three different pH values (3, 5 and 7), while bioaccumulation of the metals, Al, Fe, Mn and Zn and glutathione S-transferase (GST) activity were measured in the different selected algae species at a constant water temperature of 14 °C. Bioaccumulation of Al was the highest for O. crassum followed by K. klebsii and M. tumidula (p < 0.0001). From the study it was evident that the highest metal bioaccumulation occurred in the macroalgae O. crassum at all three tested pH values under constant low water temperature. PMID:24835955

  14. The Potential for Measuring Slow Crustal Evolution using Ar-Ar Dating of Large K-feldspar Crystals

    NASA Astrophysics Data System (ADS)

    Kelley, S. P.; Flude, S.

    2012-12-01

    There has been a great deal of debate concerning Ar/Ar age profiles in K-feldspar, even gem quality K-feldspar which should exhibit simple diffusion behaviour. Here we explore their potential for measuring very slow crustal evolution and cratonization. Several different models have been evoked which if correct would challenge our capability to recover long thermal histories from Ar/Ar data. We have measured 40Ar/39Ar ages in gem quality K-feldspar grains from Itrongay Madagascar of 435 [1] - 477 [2] Ma using UV-laserprobe to produce both depth profiles (0-20 microns) and spot traverses (0-1000 microns) to test the mechanisms that might control Ar diffusion in nature. Micron scale UV laser depth profiling was used to determine Ar diffusion adjacent to the natural crystal surface (presumed to have formed as the sample crystallised). UV laser spot dating was used to measure the age variations on length scales of 10s of microns to mm and even cm. The high potassium content and age of the Itrongay sample made it possible to measure natural argon age profiles at high precision and high spatial resolution, to address some of the issues surrounding Ar diffusion. The analysis reveals the presence of very long age gradients in the Itrongay feldspar spanning more than 50Ma - ages as low as 415.7±3.0 Ma were measured at the grain margin and as high as 473.8±2.2 Ma in the core. As previous work on Itrongay feldspar has tended to be carried out on mm-sized fragments without knowledge of the original crystal boundaries, the variation in radiometric ages in the published literature is likely due to these internal age variations. We interpret the age profiles as the combination of diffusion and 40K decay to 40Ar over the full range of spatial scales from micron to centimetre. Thermal models for the thermal history of Itrongay K-feldspar appear to be in agreement with previous thermochronology in the area and hold out the hope for unravelling very long and slow crustal evolution based on the deep crust which might be tied into slowly evolving landforms on the surface. 1. Arnaud, N. O., and S. P. Kelley. 1997. "Argon behaviour in gem-quality orthoclase from Madagascar: Experiments and some consequences for 40Ar/39Ar geochronology." Geochimica et Cosmochimica Acta. 61, 3227-3255. 2. Nägler, Th. F., and I. M. Villa. 2000. "In pursuit of the 40K branching ratios: K-Ca and 39Ar-40Ar dating of gem silicates." Chemical Geology. 169 , 5-16.

  15. pH-Sensitive cationic copolymers of different macromolecular architecture as potential dexamethasone sodium phosphate delivery systems.

    PubMed

    Georgieva, Dilyana; Kostova, Bistra; Ivanova, Sijka; Rachev, Dimitar; Tzankova, Virginia; Kondeva-Burdina, Magdalena; Christova, Darinka

    2014-08-01

    This paper describes the synthesis and characterization of cationic copolymers with different macromolecular architecture and drug delivery properties of the corresponding dexamethasone sodium phosphate (DSP)-loaded systems. Copolyelectrolytes comprising poly[2-(acryloyloxy)ethyl] trimethylammonium chloride (PAETMAC) and poly(ethylene glycol) blocks as well as a tri-arm star-shaped PAETMAC were synthesized using cerium(IV) ion-mediated polymerization method. The obtained copolyelectrolytes and corresponding ionic associates with DSP have been characterized by (1)H NMR, Fourier Transform Infrared spectroscopy, and differential scanning calorimetry. The average diameter, size distribution, and ?-potential of the copolymers and DSP-copolymer ionic associates were determined by dynamic light scattering, and particles were visualized by scanning electron microscopy and transmission electron microscopy. The biocompatibility and cytotoxicity of obtained copolymers were determined. In vitro drug release experiments were carried out to estimate the ability of the obtained nanoparticles for sustained release of DSP for a period of 24 h. PMID:24961490

  16. Integral representation of voltage in half-plane conductor with crack from surface by D.C. potential difference method

    NASA Astrophysics Data System (ADS)

    Akira, Sasamoto; Krutitskii, P. A.

    2012-09-01

    Non destructive testing (NDT) has been used to ensure safety in public structure and public space. D.C. potential difference method, one of the NDT, can detect crack in conductive material. According to study for material, depth of crack in metal is most important parameter to judge if the crack will lead catastrophic failure in short time. Therefore estimation of crack depth by measured voltage on surface is key process in the method. However, as authors as know, exact solution of model equation for the method that is Laplace equation with prescribed boundary condition and crack has not been known so far. In this paper we show exact expression of solution and computational results for model problem described in two space dimensional lower half-space with crack vertically propagating from the surface.

  17. Different Timing Features in Brain Processing of Core and Moral Disgust Pictures: An Event-Related Potentials Study

    PubMed Central

    Zhang, Youxue; Lou, Liandi; Ding, Daoqun

    2015-01-01

    Disgust, an emotion motivating withdrawal from offensive stimuli, protects us from the risk of biological pathogens and sociomoral violations. Homogeneity of its two types, namely, core and moral disgust has been under intensive debate. To examine the dynamic relationship between them, we recorded event-related potentials (ERPs) for core disgust, moral disgust and neutral pictures while participants performed a modified oddball task. ERP analysis revealed that N1 and P2 amplitudes were largest for the core disgust pictures, indicating automatic processing of the core disgust-evoking pictures. N2 amplitudes were higher for pictures evoking moral disgust relative to core disgust and neutral pictures, reflecting a violation of social norms. The core disgust pictures elicited larger P3 and late positive potential (LPP) amplitudes in comparison with the moral disgust pictures which, in turn, elicited larger P3 and LPP amplitudes when compared to the neutral pictures. Taken together, these findings indicated that core and moral disgust pictures elicited different neural activities at various stages of information processing, which provided supporting evidence for the heterogeneity of disgust. PMID:26011635

  18. Potential effects of climate change on the growth of fishes from different thermal guilds in Lakes Michigan and Huron

    USGS Publications Warehouse

    Kao, Yu-Chun; Madenjian, Charles P.; Bunnell, David; Lofgren, Brent M.; Perroud, Marjorie

    2015-01-01

    We used a bioenergetics modeling approach to investigate potential effects of climate change on the growth of two economically important native fishes: yellow perch (Perca flavescens), a cool-water fish, and lake whitefish (Coregonus clupeaformis), a cold-water fish, in deep and oligotrophic Lakes Michigan and Huron. For assessing potential changes in fish growth, we contrasted simulated fish growth in the projected future climate regime during the period 2043-2070 under different prey availability scenarios with the simulated growth during the baseline (historical reference) period 1964-1993. Results showed that effects of climate change on the growth of these two fishes are jointly controlled by behavioral thermoregulation and prey availability. With the ability of behavioral thermoregulation, temperatures experienced by yellow perch in the projected future climate regime increased more than those experienced by lake whitefish. Thus simulated future growth decreased more for yellow perch than for lake whitefish under scenarios where prey availability remains constant into the future. Under high prey availability scenarios, simulated future growth of these two fishes both increased but yellow perch could not maintain the baseline efficiency of converting prey consumption into body weight. We contended that thermal guild should not be the only factor used to predict effects of climate change on the growth of a fish, and that ecosystem responses to climate change should be also taken into account.

  19. Does size difference in allogeneic cancellous bone granules loaded with differentiated autologous cultured osteoblasts affect osteogenic potential?

    PubMed

    Lee, Sang-Uk; Chung, Yang-Guk; Kim, Seok-Jung; Oh, Il-Hoan; Kim, Yong-Sik; Ju, Sung-Hun

    2014-02-01

    We study the efficacy of bone regeneration by using two differently sized allogeneic cancellous bone granules loaded with autologous cultured osteoblasts in a rabbit model. Critical-sized bone defects of the radial shaft were made in 40 New Zealand White rabbits. Small allogeneic bone granules (150-300 ?m in diameter) loaded with cultured differentiated autologous osteoblasts were implanted into one forearm (SBG group) and large bone granules (500-710 ?m) loaded with osteoblasts were implanted into the forearm of the other side (LBG group). Radiographic evaluations were performed at 3, 6, 9 and 12 weeks and histology and micro-CT image analysis were carried out at 6 and 12 weeks post-implantation. On radiographic evaluation, the LBG group showed a higher bone quantity index at 3 and 6 weeks post-implantation (P < 0.05) but statistical significance was lost at 9 and 12 weeks. The progression of biological processes of the SBG group was faster than that of the LBG group. On micro-CT image analysis, the LBG group revealed a higher total bone volume and surface area than the SBG group at 6 weeks (P < 0.05) but the difference decreased at 12 weeks and was without statistical significance. Histological evaluation also revealed faster progression of new bone formation and maturation in the SBG group. Thus, the two differently sized allogeneic bone granules loaded with co-cultured autologous osteoblasts show no differences in the amount of bone regeneration, although the SBG group exhibits faster progression of bone regeneration and remodeling. This method might therefore provide benefits, such as a short healing time and easy application in an injectable form, in a clinical setting. PMID:24346683

  20. Finite-difference simulation of borehole EM logging measurements in 3D anisotropic subsurface media using coupled potentials

    E-print Network

    Torres-Verdín, Carlos

    auxiliary potentials as aids in obtaining solutions for the EM fields. Hence, EM potential formulations a single DC scalar potential function. Numerical tests showed that the correction method drastically media using coupled potentials Junsheng Hou and Carlos Torres-Verdín Department of Petroleum

  1. Different environmental conditions, different results: the role of controlled environmental stress on grape quality potential and the way to monitor it

    Microsoft Academic Search

    C. van Leeuwen; O. Trégoat; X. Choné; J.-P. Gaudillère; D. Pernet

    Environmental stress, such as water deficit or limited nitrogen availability, reduces grape yield, but generally promotes grape quality potential for red table wine production. Limited nitrogen uptake limits grape yield but enhances grape quality potential for red table wine production, because it reduces berry size and enhances phenolic compound synthesis. Water deficit stress has one negative effect (reduction of photosynthesis),

  2. Use of different organic wastes as strategy to mitigate the leaching potential of phenylurea herbicides through the soil.

    PubMed

    Fenoll, José; Garrido, Isabel; Hellín, Pilar; Flores, Pilar; Vela, Nuria; Navarro, Simón

    2015-03-01

    In this study, the leaching of 14 substituted phenylurea herbicides (PUHs) through disturbed soil columns packed with three different soils was investigated in order to determine their potential for groundwater pollution. Simultaneously, a series of experiments were conducted to demonstrate the effect of four different organic wastes (composted sheep manure (CSM), composted pine bark (CPB), spent coffee grounds (SCG) and coir (CR)) on their mobility. All herbicides, except difenoxuron, showed medium/high leachability through the unamended soils. In general, addition of agro-industrial and composted organic wastes at a rate of 10% (w/w) increased the adsorption of PUHs and decreased their mobility in the soil, reducing their leaching. In all cases, the groundwater ubiquity score (GUS) index was calculated for each herbicide on the basis of its persistence (as t ½) and mobility (as K OC). The results obtained point to the interest in the use of agro-industrial and composted organic wastes in reducing the risk of groundwater pollution by pesticide drainage. PMID:25296939

  3. Humin as an electron donor for enhancement of multiple microbial reduction reactions with different redox potentials in a consortium.

    PubMed

    Zhang, Dongdong; Zhang, Chunfang; Xiao, Zhixing; Suzuki, Daisuke; Katayama, Arata

    2015-02-01

    A solid-phase humin, acting as an electron donor, was able to enhance multiple reductive biotransformations, including dechlorination of pentachlorophenol (PCP), dissimilatory reduction of amorphous Fe (III) oxide (FeOOH), and reduction of nitrate, in a consortium. Humin that was chemically reduced by NaBH4 served as an electron donor for these microbial reducing reactions, with electron donating capacities of 0.013 mmol e(-)/g for PCP dechlorination, 0.15 mmol e(-)/g for iron reduction, and 0.30 mmol e(-)/g for nitrate reduction. Two pairs of oxidation and reduction peaks within the humin were detected by cyclic voltammetry analysis. 16S rRNA gene sequencing-based microbial community analysis of the consortium incubated with different terminal electron acceptors, suggested that Dehalobacter sp., Bacteroides sp., and Sulfurospirillum sp. were involved in the PCP dechlorination, dissimilatory iron reduction, and nitrate reduction, respectively. These findings suggested that humin functioned as a versatile redox mediator, donating electrons for multiple respiration reactions with different redox potentials. PMID:25176636

  4. Expression of different neurokinin-1 receptor (NK1R) isoforms in glioblastoma multiforme: potential implications for targeted therapy.

    PubMed

    Cordier, Dominik; Gerber, Alexandra; Kluba, Christiane; Bauman, Andreas; Hutter, Gregor; Mindt, Thomas L; Mariani, Luigi

    2014-06-01

    In clinical trials, overexpression of neurokinin-1 receptors (NK1R) in gliomas has been exploited by intratumoral injection of its radiolabeled ligand, substance P (SP). However, despite proven NK1R expression, patients' response to the therapy was inhomogeneous. This study aims to identify the factors predicting response to NK1R-targeted glioma therapy, thereby allowing the discrimination between potential "responders" and "nonresponders" and thus a personalized therapeutic approach. Four widely used glioblastoma cell lines were examined concerning their RNA levels of full-length and truncated NK1R subtypes. Binding of SP to NK1R and internalization into glioma cells was studied by three different approaches using radiolabeled SP ((177)Lu-[DOTA, Thi(8), Met(O2)(11)]-SP), a fluorescence-labeled SP derivative (SP-FAM), and a toxin-SP conjugate (saporin-SP). While NK1R RNA was detected in all cases, receptor subtype analysis revealed impressive differences between the cell lines; LN319 exhibited the highest level of full-length NK1R RNA. Significant binding of SP conjugates to NK1R, cell internalization, and specific cell killing were only observed with the cell line LN319. Thus, different NK1R subtype profiles of glomerular basement membrane (GBM) cell lines appear to influence the binding of SP conjugates and their cell internalization properties. Both processes are crucial steps for NK1R-based targeted therapy. Pretherapeutic testing for NK1R subtype expression may therefore be advisable before initiation of this generally promising therapeutic modality. PMID:24552486

  5. An Evaluation of the Environmental Impact of Different Commercial Supermarket Refrigeration Systems Using Low Global Warming Potential Refrigerants

    SciTech Connect

    Beshr, Mohamed [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Radermacher, Reinhard [University of Maryland, College Park

    2014-01-01

    Commercial refrigeration systems consumed 1.21 Quads of primary energy in 2010 and are known to be a major source for refrigerant charge leakage into the environment. Thus, it is important to study the environmental impact of commercial supermarket refrigeration systems and improve their design to minimize any adverse impacts. The system s Life Cycle Climate Performance (LCCP) was presented as a comprehensive metric with the aim of calculating the equivalent mass of carbon dioxide released into the atmosphere throughout its lifetime, from construction to operation and destruction. In this paper, an open source tool for the evaluation of the LCCP of different air-conditioning and refrigeration systems is presented and used to compare the environmental impact of a typical multiplex direct expansion (DX) supermarket refrigeration systems based on three different refrigerants as follows: two hydrofluorocarbon (HFC) refrigerants (R-404A, and R-407F), and a low global warming potential (GWP) refrigerant (N-40). The comparison is performed in 8 US cities representing different climates. The hourly energy consumption of the refrigeration system, required for the calculation of the indirect emissions, is calculated using a widely used building energy modeling tool (EnergyPlus). A sensitivity analysis is performed to determine the impact of system charge and power plant emission factor on the LCCP results. Finally, we performed an uncertainty analysis to determine the uncertainty in total emissions for both R-404A and N-40 operated systems. We found that using low GWP refrigerants causes a considerable drop in the impact of uncertainty in the inputs related to direct emissions on the uncertainty of the total emissions of the system.

  6. Multiple Breast Cancer Cell-Lines Derived from a Single Tumor Differ in Their Molecular Characteristics and Tumorigenic Potential

    PubMed Central

    Mosoyan, Goar; Nagi, Chandandeep; Marukian, Svetlana; Teixeira, Avelino; Simonian, Anait; Resnick-Silverman, Lois; DiFeo, Analisa; Johnston, Dean; Reynolds, Sandra R.; Roses, Daniel F.; Mosoian, Arevik

    2013-01-01

    Background Breast cancer cell lines are widely used tools to investigate breast cancer biology and to develop new therapies. Breast cancer tissue contains molecularly heterogeneous cell populations. Thus, it is important to understand which cell lines best represent the primary tumor and have similarly diverse phenotype. Here, we describe the development of five breast cancer cell lines from a single patient’s breast cancer tissue. We characterize the molecular profiles, tumorigenicity and metastatic ability in vivo of all five cell lines and compare their responsiveness to 4-hydroxytamoxifen (4-OHT) treatment. Methods Five breast cancer cell lines were derived from a single patient’s primary breast cancer tissue. Expression of different antigens including HER2, estrogen receptor (ER), CK8/18, CD44 and CD24 was determined by flow cytometry, western blotting and immunohistochemistry (IHC). In addition, a Fuorescent In Situ Hybridization (FISH) assay for HER2 gene amplification and p53 genotyping was performed on all cell lines. A xenograft model in nude mice was utilized to assess the tumorigenic and metastatic abilities of the breast cancer cells. Results We have isolated, cloned and established five new breast cancer cell lines with different tumorigenicity and metastatic abilities from a single primary breast cancer. Although all the cell lines expressed low levels of ER, their growth was estrogen-independent and all had high-levels of expression of mutated non-functional p53. The HER2 gene was rearranged in all cell lines. Low doses of 4-OHT induced proliferation of these breast cancer cell lines. Conclusions All five breast cancer cell lines have different antigenic expression profiles, tumorigenicity and organ specific metastatic abilities although they derive from a single tumor. None of the studied markers correlated with tumorigenic potential. These new cell lines could serve as a model for detailed genomic and proteomic analyses to identify mechanisms of organ-specific metastasis of breast cancer. PMID:23372829

  7. Gender Differences in Reading Impairment and in the Identification of Impaired Readers: Results from a Large-Scale Study of At-Risk Readers

    ERIC Educational Resources Information Center

    Quinn, Jamie M.; Wagner, Richard K.

    2015-01-01

    Reading impairment is more common in males, but the magnitude and origin of this gender difference are debated. In a large-scale study of reading impairment among 491,103 beginning second-graders, gender differences increased with greater severity of reading impairment, peaking at a ratio of 2.4:1 for a broad measure of fluency and a ratio of…

  8. Ionization potentials of CH2: A comparison of the multiconfigurational spin tensor electron propagator method with benchmark full configuration interaction and large scale multireference configuration interaction calculations

    NASA Astrophysics Data System (ADS)

    Nichols, Jeffrey A.; Heryadi, Dodi; Yeager, Danny L.; Golab, Joseph T.

    1994-02-01

    Using the same basis sets and geometries as were previously used in ``benchmark'' full configuration interaction (FCI) calculations we compare the multiconfigurational spin tensor electron propagator method (MCSTEP) with FCI for the vertical ionization potentials (IPs) in CH2 below 19.0 eV. Our results show that MCSTEP using a full valence complete active space MCSCF initial state accurately obtains the lowest several principal vertical ionization potentials. We also determine vertical and adiabatic IPs in CH2 with MCSTEP using larger bases and compare to accurate large scale multireference singles and doubles CI with quadruple excitations estimated via a Davidson correction.

  9. Estimating the factors restricting potential dynamic range in the optical scheme of acousto-optical spectrometer for the Mexican Large Millimeter Telescope

    NASA Astrophysics Data System (ADS)

    Shcherbakov, Alexandre S.; Balderas Mata, Sandra E.; Sanchez Lucero, D.

    2007-09-01

    Here, we consider one of the most important problems related to optimizing the performance data of a new acoustooptical spectrometer for the analysis of radio-astronomical signals. The main attention is paid to estimating two factors governing the dynamic range of that spectrometer. At first, we determine the influence of the acoustic attenuation along a large-aperture acousto-optical cell on potential levels of lobes in focal plane of the integrating lens and then describe capabilities of the incident light beam apodization for increasing the dynamic range of spectrometer. These studies lie in a line with the program of developing metrological equipment for Mexican Large Millimeter Telescope.

  10. Somatosensory evoked potential spinal cord monitoring reduces neurologic deficits after scoliosis surgery: results of a large multicenter survey

    Microsoft Academic Search

    Marc R. Nuwer; Edgar G. Dawson; Linda G. Carlson; Linda E. A. Kanim; John E. Sherman

    1995-01-01

    Neurologic deficits were compared to somatosensory evoked potential (SEP) spinal cord monitoring in a survey of spinal orthopedic surgeons. Experienced SEP spinal cord monitoring teams had fewer than one-half as many neurologic deficits per 100 cases compared to teams with relatively little monitoring experience. Experienced SEP monitoring teams also had fewer neurologic deficits than were seen in previous surveys of

  11. Pre- and postnatal differences in membrane, action potential, and ion channel properties of rostral nucleus of the solitary tract neurons.

    PubMed

    Suwabe, Takeshi; Mistretta, Charlotte M; Krull, Catherine; Bradley, Robert M

    2011-11-01

    There is little known about the prenatal development of the rostral nucleus of the solitary tract (rNST) neurons in rodents or the factors that influence circuit formation. With morphological and electrophysiological techniques in vitro, we investigated differences in the biophysical properties of rNST neurons in pre- and postnatal rats from embryonic day 14 (E14) through postnatal day 20. Developmental changes in passive membrane and action potential (AP) properties and the emergence and maturation of ion channels important in neuron function were characterized. Morphological maturation of rNST neurons parallels changes in passive membrane properties. Mean soma size, dendritic branch points, neurite endings, and neurite length all increase prenatally. whereas neuron resting membrane potential, input resistance, and time constant decrease. Dendritic spines, on the other hand, develop after birth. AP discharge patterns alter in pre- and postnatal stages. At E14, neurons generated a single TTX-sensitive, voltage-gated Na(+) AP when depolarized; a higher discharge rate appeared at older stages. AP amplitude, half-width, and rise and fall times all change during development. Responses to current injection revealed a number of voltage-gated conductances in embryonic rNST, including a hyperpolarization-activated inward current and a low-threshold Ca(2+) current that initiated Ca(2+) spikes. A hyperpolarization-activated, transient outward potassium current was also present in the developing neurons. Although the properties of these channels change during development, they are present before synapses form and therefore, can contribute to initial establishment of neural circuits, as well as to the changing electrophysiological properties in developing rNST neurons. PMID:21865434

  12. Magnetic resonance imaging of the knee in Norway 2002–2004 (national survey): rapid increase, older patients, large geographic differences

    PubMed Central

    Espeland, Ansgar; Natvig, Nils L; Løge, Ingard; Engebretsen, Lars; Ellingsen, Jostein

    2007-01-01

    Background Magnetic resonance imaging (MRI) of the knee is the second most common MRI examination in Norway after head/brain MRI. Little has been published internationally on trends in the use of knee MRI after 1999. This study aimed to describe levels and trends in ambulant knee MRI utilisation in Norway 2002–2004 in relation to type of radiology service, geographic regions, number of MRI-scanners, patient age and gender, and type of referring health care provider. Methods We analysed administrative data on all claims for reimbursement of ambulant knee MRI performed in Norway in 2002, 2003 and 2004 and noted nominal reimbursement. We also recorded the referring health care provider from clinical requests of ambulant knee MRI done consecutively during two months in 2004 at one private institute and three hospitals. Number of MRI-scanners was given by manufacturers and radiology services. Results In Norway, the rate of knee MRI claims for 2004 was 15.6 per 1000 persons. This rate was 74% higher in East than in North region (18.4 vs. 10.6), slightly higher for men than women (16.4 vs. 14.7) and highest for ages 50–59 years (29.0) and 60–69 years (21.2). Most claims (76% for 2004) came from private radiology services. In 2004, the referring health care provider was a general practitioner in 63% of claims (unspecified in 24%) and in 83.5% (394/472) of clinical requests. From 2002 to 2004, the rate of knee MRI claims increased 64%. In the age group 50 years or above the increase was 86%. Rate of MRI-scanners increased 43% to 21 scanners per million persons in 2004. Reimbursement for knee MRI claims (nominal value) increased 80% to 70 million Norwegian kroner in 2004. Conclusion Ambulant knee MRI utilisation in Norway increases rapidly especially for patients over 50, and shows large geographic differences. Evaluation of clinical outcomes of this activity is needed together with clinical guidelines for use of knee MRI. PMID:17659090

  13. Anti-glomerular basement membrane disease: outcomes of different therapeutic regimens in a large single-center Chinese cohort study.

    PubMed

    Cui, Zhao; Zhao, Juan; Jia, Xiao-yu; Zhu, Sai-nan; Jin, Qi-zhuang; Cheng, Xu-yang; Zhao, Ming-hui

    2011-09-01

    Anti-glomerular basement membrane (GBM) disease usually presents with rapidly progressive glomerulonephritis accompanied by pulmonary hemorrhage. The low incidence and fulminant course of disease preclude a large randomized controlled study to define the benefits of any given therapy. We conducted a retrospective survey of 221 consecutive patients seen from 1998 to 2008 in our hospital, and report here the patient and renal survival and the risk factors affecting the outcomes. Considering the similar clinical features of the patients, we could compare the effects of 3 different treatment regimens: 1) combination therapy of plasmapheresis and immunosuppression, 2) steroids and cytotoxic agents, and 3) steroids alone.The patient and renal survival rates were 72.7% and 25.0%, respectively, at 1 year after disease presentation. The serum level of anti-GBM antibodies (increased by 20 U/mL; hazard ratio [HR], 1.16; p = 0.009) and the presentation of positive antineutrophil cytoplasmic antibodies (ANCA) (HR, 2.18; p = 0.028) were independent predictors for patient death. The serum creatinine at presentation (doubling from 1.5 mg/dL; HR, 2.07; p < 0.001) was an independent predictor for renal failure.The combination therapy of plasmapheresis plus corticosteroids and cyclophosphamide had an overall beneficial effect on both patient survival (HR for patient mortality, 0.31; p = 0.001) and renal survival (HR for renal failure, 0.60; p = 0.032), particularly patient survival for those with Goodpasture syndrome (HR for patient mortality, 0.29; p = 0.004) and renal survival for those with anti-GBM nephritis with initial serum creatinine over 6.8 mg/dL (HR for renal failure, 0.52; p = 0.014). The treatment with corticosteroids plus cyclophosphamide was found not to improve the renal outcome of disease (p = 0.73). In conclusion, the combination therapy was preferred for patients with anti-GBM disease, especially those with pulmonary hemorrhage or severe renal damage. Early diagnosis was crucial to improving outcomes. PMID:21862934

  14. Mechanisms underlying fictive feeding in aplysia: coupling between a large neuron with plateau potentials activity and a spiking neuron.

    PubMed

    Susswein, Abraham J; Hurwitz, Itay; Thorne, Richard; Byrne, John H; Baxter, Douglas A

    2002-05-01

    The buccal ganglia of Aplysia contain a central pattern generator (CPG) that organizes the rhythmic movements of the radula and buccal mass during feeding. Many of the cellular and synaptic elements of this CPG have been identified and characterized. However, the roles that specific cellular and synaptic properties play in generating patterns of activity are not well understood. To examine these issues, the present study developed computational models of a portion of this CPG and used simulations to investigate processes underlying the initiation of patterned activity. Simulations were done with the SNNAP software package. The simulated network contained two neurons, B31/B32 and B63. The development of the model was guided and constrained by the available current-clamp data that describe the properties of these two protraction-phase interneurons B31/B32 and B63, which are coupled via electrical and chemical synapses. Several configurations of the model were examined. In one configuration, a fast excitatory postsynaptic potential (EPSP) from B63 to B31/B32 was implemented in combination with an endogenous plateau-like potential in B31/B32. In a second configuration, the excitatory synaptic connection from B63 to B31/B32 produced both fast and slow EPSPs in B31/B32 and the plateau-like potential was removed from B31/B32. Simulations indicated that the former configuration (i.e., electrical and fast chemical coupling in combination with a plateau-like potential) gave rise to a circuit that was robust to changes in parameter values and stochastic fluctuations, that closely mimicked empirical observations, and that was extremely sensitive to inputs controlling the onset of a burst. The coupling between the two simulated neurons served to amplify exogenous depolarizations via a positive feedback loop and the subthreshold activation of the plateau-like potential. Once a burst was initiated, the circuit produced the program in an all-or-none fashion. The slow kinetics of the simulated plateau-like potential played important roles in both initiating and maintaining the burst activity. Thus the present study identified cellular and network properties that contribute to the ability of the simulated network to integrate information over an extended period before a decision is made to initiate a burst of activity and suggests that similar mechanisms may operate in the buccal ganglia in initiating feeding movements. PMID:11976370

  15. 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

    ... Does it make a difference whether the claim...AND INDIAN HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES CONTRACTS UNDER... Does it make a difference whether the claim...claim is made in good faith,...

  16. On the contribution of external cost calculations to energy system governance: The case of a potential large-scale nuclear accident

    Microsoft Academic Search

    Erik Laes; Gaston Meskens; Jeroen P. van der Sluijs

    2011-01-01

    The contribution of nuclear power to a sustainable energy future is a contested issue. This paper presents a critical review of an attempt to objectify this debate through the calculation of the external costs of a potential large-scale nuclear accident in the ExternE project. A careful dissection of the ExternE approach resulted in a list of 30 calculation steps and

  17. Smoking-attributable deaths and potential years of life lost from a large, representative study in China

    Microsoft Academic Search

    Jingmei Jiang; Boqi Liu; Freddy Sitas; Junyao Li; Xianjia Zeng; Wei Han; Xiaonong Zou; Yanping Wu; Ping Zhao

    2009-01-01

    ObjectivesTo provide a more accurate estimate of early smoking-attributable mortality and potential years of life lost using data from a representative study of 103 study areas in China.MethodsTwo datasets were employed as follows. Firstly, retrospective national mortality survey data, which included a population of 67 million in 103 study areas, and about 1 million adults who died in 1986–1988; secondly,

  18. Potential for large-scale submarine slope failure and tsunami generation along the U.S. mid-Atlantic coast

    Microsoft Academic Search

    Neal W. Driscoll; Jeffrey K. Weissel; John A. Goff

    2000-01-01

    The outer continental shelf off southern Virginia and North Carolina might be in the initial stages of large-scale slope failure. A system of en echelon cracks, resembling small-offset normal faults, has been discovered along the outer shelf edge. Swath bathymetric data indicate that about 50 m of down-to-the-east (basinward) normal slip has occurred on these features. From a societal perspective,

  19. On the factors behind large Labrador Sea tides during the last glacial cycle and the potential implications for Heinrich events

    Microsoft Academic Search

    Brian K. Arbic; Jerry X. Mitrovica; Douglas R. MacAyeal; Glenn A. Milne

    2008-01-01

    Labrador Sea (LS) tidal elevations over the last glacial cycle are investigated in a near-global numerical model that accurately captures the present-day tides. From ?65 ka to ?7 ka, the modeled elevations at the debouchement point of the Hudson Strait ice stream in the LS are exceptionally large, comparable to the largest elevations seen anywhere in the present-day ocean. New

  20. Increased expression of the large GTPase dynamin 2 potentiates metastatic migration and invasion of pancreatic ductal carcinoma

    Microsoft Academic Search

    R D Eppinga; E W Krueger; S G Weller; L Zhang; H Cao; M A McNiven

    2012-01-01

    Pancreatic ductal tumors invade local parenchyma and metastasize to distant organs. Src-mediated tyrosine kinase signaling pathways promote pancreatic ductal adenocarcinoma (PDAC) metastasis, though the molecular mechanisms supporting this invasive process are poorly understood and represent important and novel therapeutic targets. The large GTPase Dynamin 2 (Dyn2), a Src-kinase substrate, regulates membrane–cytoskeletal dynamics although it is yet to be defined if

  1. Prescription of potentially inappropriate medication in older persons in Switzerland: does the dispensing channel make a difference?

    PubMed Central

    Blozik, Eva; Rapold, Roland; Reich, Oliver

    2015-01-01

    Background Drugs can be supplied either directly from the prescribing physician (physician dispensing [PD]) or via a pharmacy. It is unclear whether the dispensing channel is associated with quality problems. Potentially inappropriate medication (PIM) is associated with adverse outcomes in older persons and can be considered a marker for quality deficits in prescribing. We investigated whether prevalence of PIM differs across dispensing channels. Patients and methods We analyzed basic health insurance claims of 50,747 person quarter years with PIM use of residents of the Swiss cantons Aargau and Lucerne of the years 2012 and 2013. PIM was identified using the Beers 2012 criteria and the PRISCUS list. We calculated PIM prevalence stratified by supply channel. Adjusted mixed effects logistic regression analysis was done to estimate the effect of obtaining medications through the dispensing physician as compared to the pharmacy channel on receipt of PIM. The most frequent PIMs were identified. Results There is a small but detectable difference in total PIM prevalence: 30.7% of the population supplied by a dispensing physician as opposed to 29.3% individuals who received medication in a pharmacy. According to adjusted logistic regression individuals who obtained the majority of their medications from their prescribing physician had a 15% higher chance to receive a PIM (odds ratio 1.15, 95% confidence interval 1.08–1.22; P<0.001). Conclusion Physician dispensing seems to affect quality and safety of drug prescriptions. Quality issues should not be neglected in the political discussion about the regulations on PD. Future studies should explore whether PD is related to other indicators of inefficiency or quality flaws. The present study also underlines the need for interventions to reduce the high rates of PIM prescribing in Switzerland. PMID:25977609

  2. Sexual differences in photosynthetic activity, ultrastructure and phytoremediation potential of Populus cathayana exposed to lead and drought.

    PubMed

    Han, Ying; Wang, Ling; Zhang, Xiaolu; Korpelainen, Helena; Li, Chunyang

    2013-10-01

    Lead (Pb) and drought frequently coexist in China's forests and seriously affect their biomass, net primary productivity and biodiversity, particularly among dioecious trees with different sex-related reproduction costs. Here, the effects of Pb, deposited into soil (Pbsoil) and leaves (Pb(leaf)), on the traits related directly or indirectly to photosynthetic activity were evaluated in the dioecious tree, Populus cathayana Rehd. In addition, we analysed the potential of P. cathayana males and females for phytoremediation based on the photosynthetic activity, cellular ultrastructure and phytoremediation-related parameters. The Pb level was 2.7 mmol Pb(NO3)2 kg(-1) dry soil in the Pb(soil) treatment and 1.8 mmol Pb(NO3)2 per plant in the Pb(leaf) treatment. In parallel experiments, two watering regimes, 100 and 50% of the field capacity, were applied. The stress duration was 2 months. Dry mass production, net photosynthetic rate increased in both sexes, particularly in females, when exposed to Pb(leaf) alone, Pb(soil) with drought and Pb(leaf) with drought. The study revealed that males exhibit greater plasticity in the photosynthetic capacity than females. Severe damage to cellular ultrastructure was also observed in the leaves of males and females exposed to Pb(leaf), but more strongly in females. However, the Pb(soil) treatment alone did not affect these traits as significantly compared with other treatments. Moreover, drought significantly increased the sensitivity to Pb stress in both sexes, but more so in females. In addition, changes in the photosynthetic capacity and cellular ultrastructure combined with the analysis of tolerance index, translocation factor, bioconcentration factor and Pb concentration showed that males and females could be employed for different purposes in phytoremediation: females are promising candidates for phytoextraction, whereas males are promising candidates for phytostabilization. PMID:24186942

  3. Hydraulic conducttince and soil water potential at the soil-root interface of Pinus pinaster seedlings inoculated with different dikaryons of Pisolithus sp

    Microsoft Academic Search

    MOHAMMED S. LAMHAMEDI; PIERRE Y. BERNIER; J. ANDRti FORTIN

    Summary 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 (Y',), soil water potential at the soil-root interface (Y,) and hydraulic conductance (&,) during and after a

  4. Mono-2-ethylhexyl phthalate stimulates androgen production but suppresses mitochondrial function in mouse leydig cells with different steroidogenic potential.

    PubMed

    Savchuk, Iuliia; Söder, Olle; Svechnikov, Konstantin

    2015-05-01

    Numerous studies have reported on testicular toxicity of phthalates in different experimental paradigms and showed that Leydig cells (LCs) were one of the main targets of phthalate actions. Adverse effects of phthalates on LCs steroidogenesis have been attributed to their metabolites, monophthalates. This study focuses on investigation whether LCs responsiveness to monophthalates action is associated with their potential to produce androgens. We found that of 3 monophthalates investigated [ie, mono-2-ethylhexyl phthalate (MEHP), mono-n-butyl phthalate, and mono-n-benzyl phthalate] only MEHP caused biological effects on the mouse LCs function. This monophthalate stimulated basal steroidogenesis associated with upregulation of StAR protein expression with no effect on hCG-stimulated androgen production by LCs from CBA/Lac and C57BL/6j mouse genotypes were observed. Further, MEHP attenuated ATP production and increased superoxide generation by both phenotypes of mouse LCs that indicated on mitochondrial dysfunction induced by the monophthalate. All together, our data indicate that MEHP-mediated stimulation of steroidogenesis and perturbation in mitochondrial function are not associated with the capacity of the LCs to synthesize androgens. We suggest that this effect of MEHP observed in LCs of rodent origin needs to be taken into consideration in analysis of earlier start of puberty in boys and may highlight a possible influence of phthalates on reproductive health in males. PMID:25677926

  5. Characteristics of oxidation-reduction potential, VFAs, SCOD, N, and P in an ATAD system under different thermophilic temperatures.

    PubMed

    Cheng, Jiehong; Kong, Feng; Zhu, Jun; Wu, Xiao

    2015-01-01

    One-stage autoheated thermophilic aerobic digestion (ATAD) can stabilize sludge to meet class A standard. In this study, batch experiments were conducted to investigate the characteristics of oxidation-reduction potential (ORP), volatile fatty acids (VFAs), soluble chemical oxygen demand (SCOD), and nutrients at different temperatures (45, 55, and 65 °C) in the one-stage ATAD. Results showed that the ORP values remained between approximately -350 and -120 mV in the primary 5-day digestion despite of excessive aeration in the digester, indicating that the aeration level could be decreased in an ATAD system to save energy. The pH exhibited a poor correlation (R (2)?

  6. Potentially Traumatic Events at Different Points in the Life Span and Mental Health: Findings From SHARE-Israel

    PubMed Central

    Shrira, Amit; Shmotkin, Dov; Litwin, Howard

    2012-01-01

    This study addressed the association between adversity cumulated at different points in the life span and present mental health. Data of 1,130 participants aged 50+ were drawn from the Israeli component of the Survey of Health, Ageing and Retirement in Europe (SHARE). Measures included an inventory of potentially traumatic events, mental distress (depressive symptoms), and well-being (quality of life, life satisfaction). Adversity reported to have occurred early in life was positively related to mental health (i.e., to lower distress and higher well-being), whereas adversity reported to occur in late life was negatively related (i.e., to higher distress and lower well-being). Additional analyses showed that the positive association between early-life adversity and mental health was mainly restricted to adversity in which the primary harm was to another person (other-oriented adversity). In contrast, the negative association between late-life adversity and mental health was mainly restricted to adversity in which the primary harm was to the self (self-oriented adversity). This study suggests that the differential association between cumulative adversity and mental health is best captured when accounting for both time of occurrence and adversity type. PMID:22506527

  7. Differences between human auditory event-related potentials (AERPs) measured at 2 and 4months after birth.

    PubMed

    van den Heuvel, Marion I; Otte, Renée A; Braeken, Marijke A K A; Winkler, István; Kushnerenko, Elena; Van den Bergh, Bea R H

    2015-07-01

    Infant auditory event-related potentials (AERPs) show a series of marked changes during the first year of life. These AERP changes indicate important advances in early development. The current study examined AERP differences between 2- and 4-month-old infants. An auditory oddball paradigm was delivered to infants with a frequent repetitive tone and three rare auditory events. The three rare events included a shorter than the regular inter-stimulus interval (ISI-deviant), white noise segments, and environmental sounds. The results suggest that the N250 infantile AERP component emerges during this period in response to white noise but not to environmental sounds, possibly indicating a developmental step towards separating acoustic deviance from contextual novelty. The scalp distribution of the AERP response to both the white noise and the environmental sounds shifted towards frontal areas and AERP peak latencies were overall lower in infants at 4 than at 2months of age. These observations indicate improvements in the speed of sound processing and maturation of the frontal attentional network in infants during this period. PMID:25896714

  8. Denitrification potential under different fertilization regimes is closely coupled with changes in the denitrifying community in a black soil.

    PubMed

    Yin, Chang; Fan, Fenliang; Song, Alin; Cui, Peiyuan; Li, Tingqiang; Liang, Yongchao

    2015-07-01

    Preferable inorganic fertilization over the last decades has led to fertility degradation of black soil in Northeast China. However, how fertilization regimes impact denitrification and its related bacterial community in this soil type is still unclear. Here, taking advantage of a suit of molecular ecological tools in combination of assaying the potential denitrification (DP), we explored the variation of activity, community structure, and abundance of nirS and nirK denitrifiers under four different fertilization regimes, namely no fertilization control (N0M0), organic pig manure (N0M1), inorganic fertilization (N1M0), and combination of inorganic fertilizer and pig manure (N1M1). The results indicated that organic fertilization increased DP, but inorganic fertilization had no impacts. The increase of DP was mirrored by the shift of nirS denitrifiers' community structure but not by that of nirK denitrifiers'. Furthermore, the change of DP coincided with the variation of abundances of both denitrifiers. Shifts of community structure and abundance of nirS and nirK denitrifiers were correlated with the change of soil pH, total nitrogen (TN), organic matter (OM), C:P, total phosphorus (TP), and available phosphorus (Olsen P). Our results suggest that the change of DP under these four fertilization regimes was closely related to the shift of denitrifying bacteria communities resulting from the variation of properties in the black soil tested. PMID:25715781

  9. Expression and activation of pro-gelatinase A by human melanoma cell lines with different tumorigenic potential.

    PubMed

    Capon, F; Emonard, H; Hornebeck, W; Maquart, F X; Bernard, P

    1999-01-01

    The production of various proteolytic enzymes by tumor cells facilitate the invasion of solid tumors into surrounding tissues. We examined three cell lines (M1Dor, M4Be and M3Da) derived from malignant melanoma which exhibited different abilities to grow in nude mice following subcutaneous grafting. By in vitro invasion assay using Boyden-chambers technique, we found that none of those cell lines were able to invade the Matrigel. Several studies have substantiated the role of matrix metalloproteinases (MMP), mainly gelatinases MMP-9 and MMP-2, in melanoma cell invasion. Each cell line constitutively produced MMP-2 (but not MMP-9) in its latent form only, with stronger production for the most tumorigenic cell line in vivo (M3Da). Integrity of the MMP-2 activation process was studied since MMP-2 was also recovered as zymogen at the cell plasma membrane. All cell lines secreted TIMP-1 and TIMP-2 in a constitutive manner and again, but TIMP-2 production as well as MT1-MMP expression were found inversely related to their tumorigenic potential. Plating cells onto type I or type IV collagen did not trigger pro-MMP-2 activation; on the contrary, conversion of pro-MMP-2 to its active form could be evidenced when melanoma cell lines were seeded in a three dimensional type I collagen lattice. PMID:10763911

  10. The own-age bias in face memory is unrelated to differences in attention--evidence from event-related potentials.

    PubMed

    Neumann, Markus F; End, Albert; Luttmann, Stefanie; Schweinberger, Stefan R; Wiese, Holger

    2015-03-01

    Participants are more accurate at remembering faces from their own relative to a different age group (the own-age bias, or OAB). A recent socio-cognitive account has suggested that differential allocation of attention to old versus young faces underlies this phenomenon. Critically, empirical evidence for a direct relationship between attention to own- versus other-age faces and the OAB in memory is lacking. To fill this gap, we tested the roles of attention in three different experimental paradigms, and additionally analyzed event-related brain potentials (ERPs). In Experiment 1, we compared the learning of old and young faces during focused versus divided attention, but revealed similar OABs in subsequent memory for both attention conditions. Similarly, manipulating attention during learning did not differentially affect the ERPs elicited by young versus old faces. In Experiment 2, we examined the repetition effects from task-irrelevant old and young faces presented under varying attentional loads on the N250r ERP component as an index of face recognition. Independent of load, the N250r effects were comparable for both age categories. Finally, in Experiment 3 we measured the N2pc as an index of attentional selection of old versus young target faces in a visual search task. The N2pc was not significantly different for the young versus the old target search conditions, suggesting similar orientations of attention to either face age group. Overall, we propose that the OAB in memory is largely unrelated to early attentional processes. Our findings therefore contrast with the predictions from socio-cognitive accounts on own-group biases in recognition memory, and are more easily reconciled with expertise-based models. PMID:24934133

  11. Systematic assessment in an animal model of the angiogenic potential of different human cell sources for therapeutic revascularization

    PubMed Central

    2012-01-01

    Introduction Endothelial progenitor cells (EPC) capable of initiating or augmenting vascular growth were recently identified within the small population of CD34-expressing cells that circulate in human peripheral blood and which are considered hematopoietic progenitor cells (HPC). Soon thereafter human HPC began to be used in clinical trials as putative sources of EPC for therapeutic vascular regeneration, especially in myocardial and critical limb ischemias. However, unlike HPC where hematopoietic efficacy is related quantitatively to CD34+ cell numbers implanted, there has been no consensus on how to measure EPC or how to assess cellular graft potency for vascular regeneration. We employed an animal model of spontaneous neovascularization to simultaneously determine whether human cells incorporate into new vessels and to quantify the effect of different putative angiogenic cells on vascularization in terms of number of vessels generated. We systematically compared competence for therapeutic angiogenesis in different sources of human cells with putative angiogenic potential, to begin to provide some rationale for optimising cell procurement for this therapy. Methods Human cells employed were mononuclear cells from normal peripheral blood and HPC-rich cell sources (umbilical cord blood, mobilized peripheral blood, bone marrow), CD34+ enriched or depleted subsets of these, and outgrowth cell populations from these. An established sponge implant angiogenesis model was adapted to determine the effects of different human cells on vascularization of implants in immunodeficient mice. Angiogenesis was quantified by vessel density and species of origin by immunohistochemistry. Results CD34+ cells from mobilized peripheral blood or umbilical cord blood HPC were the only cells to promote new vessel growth, but did not incorporate into vessels. Only endothelial outgrowth cells (EOC) incorporated into vessels, but these did not promote vessel growth. Conclusions These studies indicate that, since EPC are very rare, any benefit seen in clinical trials of HPC in therapeutic vascular regeneration is predominantly mediated by indirect proangiogenic effects rather than through direct incorporation of any rare EPC contained within these sources. It should be possible to produce autologous EOC for therapeutic use, and evaluate the effect of EPC distinct from, or in synergy with, the proangiogenic effects of HPC therapies. PMID:22759659

  12. Stability enhancement of an electrically tunable colloidal photonic crystal using modified electrodes with a large electrochemical potential window

    SciTech Connect

    Shim, HongShik [Samsung Advanced Institute of Technology, Yongin-Si, Gyeonggi-do (Korea, Republic of); Department of Chemistry, Seoul National University, Seoul (Korea, Republic of); Gyun Shin, Chang; Heo, Chul-Joon; Jeon, Seog-Jin; Jin, Haishun; Woo Kim, Jung; Jin, YongWan; Lee, SangYoon; Gyu Han, Moon, E-mail: moongyu.han@samsung.com, E-mail: jinklee@snu.ac.kr [Samsung Advanced Institute of Technology, Yongin-Si, Gyeonggi-do (Korea, Republic of); Lim, Joohyun; Lee, Jin-Kyu, E-mail: moongyu.han@samsung.com, E-mail: jinklee@snu.ac.kr [Department of Chemistry, Seoul National University, Seoul (Korea, Republic of)

    2014-02-03

    The color tuning behavior and switching stability of an electrically tunable colloidal photonic crystal system were studied with particular focus on the electrochemical aspects. Photonic color tuning of the colloidal arrays composed of monodisperse particles dispersed in water was achieved using external electric field through lattice constant manipulation. However, the number of effective color tuning cycle was limited due to generation of unwanted ions by electrolysis of the water medium during electrical switching. By introducing larger electrochemical potential window electrodes, such as conductive diamond-like carbon or boron-doped diamond, the switching stability was appreciably enhanced through reducing the number of ions generated.

  13. Stability enhancement of an electrically tunable colloidal photonic crystal using modified electrodes with a large electrochemical potential window

    NASA Astrophysics Data System (ADS)

    Shim, HongShik; Gyun Shin, Chang; Heo, Chul-Joon; Jeon, Seog-Jin; Jin, Haishun; Woo Kim, Jung; Jin, YongWan; Lee, SangYoon; Lim, Joohyun; Gyu Han, Moon; Lee, Jin-Kyu

    2014-02-01

    The color tuning behavior and switching stability of an electrically tunable colloidal photonic crystal system were studied with particular focus on the electrochemical aspects. Photonic color tuning of the colloidal arrays composed of monodisperse particles dispersed in water was achieved using external electric field through lattice constant manipulation. However, the number of effective color tuning cycle was limited due to generation of unwanted ions by electrolysis of the water medium during electrical switching. By introducing larger electrochemical potential window electrodes, such as conductive diamond-like carbon or boron-doped diamond, the switching stability was appreciably enhanced through reducing the number of ions generated.

  14. A Microsatellite Linkage Map of Rainbow Trout (Oncorhynchus mykiss) Characterized by Large Sex-Specific Differences in Recombination Rates

    Microsoft Academic Search

    Takashi Sakamoto; Roy G. Danzmann; Karim Gharbi; Pamela Howard; Akiyuki Ozaki; Sok Kean Khoo; Rachael A. Woram; Nobuaki Okamoto; Moira M. Ferguson; Lars-Erik Holm; Bjorn Hoyheim

    We constructed a genetic linkage map for a tetraploid derivative species, the rainbow trout (Oncorhynchus mykiss), using 191 microsatellite, 3 RAPD, 7 ESMP, and 7 allozyme markers in three backcross families. The linkage map consists of 29 linkage groups with potential arm displacements in the female map due to male-specific pseudolinkage arrangements. Synteny of duplicated microsatellite markers was used to

  15. Genetic control of Aedes aegypti: data-driven modelling to assess the effect of releasing different life stages and the potential for long-term suppression

    PubMed Central

    2014-01-01

    Background Control of the world’s most important vector-borne viral disease, dengue, is a high priority. A lack of vaccines or effective vector control methods means that novel solutions to disease control are essential. The release of male insects carrying a dominant lethal (RIDL) is one such approach that could be employed to control Aedes aegypti. To maximise the potential of RIDL control, optimum release strategies for transgenic mosquitoes are needed. The use of field data to parameterise models allowing comparisons of the release of different life-stages is presented together with recommendations for effective long-term suppression of a wild Ae. aegypti population. Methods A compartmental, deterministic model was designed and fitted to data from large-scale pupal mark release recapture (MRR) field experiments to determine the dynamics of a pupal release. Pulsed releases of adults, pupae or a combination of the two were simulated. The relative ability of different release methods to suppress a simulated wild population was examined and methods to maintain long-term suppression of a population explored. Results The pupal model produced a good fit to field data from pupal MRR experiments. Simulations using this model indicated that adult-only releases outperform pupal-only or combined releases when releases are frequent. When releases were less frequent pupal-only or combined releases were a more effective method of distributing the insects. The rate at which pupae eclose and emerge from release devices had a large influence on the relative efficacy of pupal releases. The combined release approach allows long-term suppression to be maintained with smaller low-frequency releases than adult- or pupal-only release methods. Conclusions Maximising the public health benefits of RIDL-based vector control will involve optimising all stages of the control programme. The release strategy can profoundly affect the outcome of a control effort. Adult-only, pupal-only and combined releases all have relative advantages in certain situations. This study successfully integrates field data with mathematical models to provide insight into which release strategies are best suited to different scenarios. Recommendations on effective approaches to achieve long-term suppression of a wild population using combined releases of adults and pupae are provided. PMID:24524678

  16. Effects of different host plants and rearing atmosphere on life cycle of large white cabbage butterfly, Pieris brassicae (Linnaeus)

    Microsoft Academic Search

    Damitre Lytan; D. M. Firake

    2012-01-01

    We studied the effect of different host plants and rearing atmosphere on life cycle of cabbage butterfly, Pieris brassicae. Insects were reared in the field (fluctuating weather) as well as in the laboratory (constant rearing conditions) on four host plants, viz. cabbage, cauliflower, knol-khol and broccoli. Significant differences were not found in the incubation and pupal period of butterfly reared

  17. A student apparatus for recording action potentials in cockroach legs

    Microsoft Academic Search

    THOMAS M. LINDER; JOHN PALKA

    potentials. As an action potential moves down an axon, ionic current flows in the extracellular spaces, causing electrical potential differences. In the cockroach leg, these potential differences may be >1 mV. The unusually large amplitude of the potentials is probably a consequence of the comparatively narrow extra- cellular spaces and thus high extracellular electrical resistances. Other types of sensors are

  18. In the midst of a large measles outbreak, EDs take steps to bolster screening procedures, prevent potential transmissions.

    PubMed

    2015-04-01

    A large, multi-state outbreak of measles is prompting EDs around the country to bolster their screening procedures and provide education to staff, most of whom have never seen a measles case. Dozens of people in more than 17 states have been confirmed to have the disease, with most of these cases associated with an outbreak that began at an amusement park in southern California. Measles is extremely contagious, infecting nine out of 10 people exposed to the virus if they are susceptible to the disease. In cases in which a contagious disease is suspected, experts advise emergency providers to protect themselves before proceeding to the traditional vital signs. It's a concept referred to as "vital sign zero." Once a measles case is confirmed, experts say emergency staff should isolate the patient with protection such as an N-95 mask, and inform both the hospital's infection control department and public health authorities. PMID:25844431

  19. Coexistence of congeneric spiny lobsters on coral reefs: differences in conspecific aggregation patterns and their potential antipredator benefits

    NASA Astrophysics Data System (ADS)

    Briones-Fourzán, P.; Lozano-Álvarez, E.

    2008-06-01

    Den sharing by conspecific spiny lobsters (aggregation) is modulated by chemical attraction but may confer several, not necessarily mutually exclusive, antipredator byproduct benefits: a “guide effect”, which only benefits the individual attracted to a sheltered conspecific; a “dilution effect”, which reduces per-capita risk of predation simply through aggregation; or active “group defense”. Each potential benefit has a different set of predictors (relationships between aggregation and conspecific or predator densities), but conflicting results could suggest the simultaneous operation of more than one benefit. These predictions were tested for coexisting Panulirus guttatus (a reef-obligate) and Panulirus argus (a temporary reef-dweller) using data collected during 11 surveys on fixed sites over a coral reef in Mexico. P. guttatus greatly outnumbered P. argus, but P. argus showed a greater tendency to aggregate. All three benefits of den sharing operated for the more social P. argus, with “group defense” being of the most benefit for larger individuals, and the “guide” and “dilution” effects for smaller individuals recently immigrating into the reef habitat and sharing dens with larger conspecifics. P. guttatus did not display “group defense” and its aggregations appeared to be modulated by the interplay between attraction and aggressive behaviors. This species relied more on solitary crypticity, especially at larger sizes, but appeared to benefit from a “guide effect” at high conspecific densities. In experimental tanks, each species tended to aggregate when tested separately, but when tested jointly, aggregation among P. guttatus was significantly reduced. The experimental results reflect the differential patterns of aggregation between the fore-reef, where P. guttatus dominated, and the back-reef, where coexistence of both species was greater.

  20. Inter-?-inhibitor blocks epithelial sodium channel activation and decreases nasal potential differences in ?F508 mice.

    PubMed

    Lazrak, Ahmed; Jurkuvenaite, Asta; Ness, Emily C; Zhang, Shaoyan; Woodworth, Bradford A; Muhlebach, Marianne S; Stober, Vandy P; Lim, Yow-Pin; Garantziotis, Stavros; Matalon, Sadis

    2014-05-01

    Increased activity of lung epithelial sodium channels (ENaCs) contributes to the pathophysiology of cystic fibrosis (CF) by increasing the rate of epithelial lining fluid reabsorption. Inter-?-inhibitor (I?I), a serum protease inhibitor, may decrease ENaC activity by preventing its cleavage by serine proteases. High concentrations of I?I were detected in the bronchoalveolar lavage fluid (BALF) of children with CF and lower airway diseases. I?I decreased amiloride-sensitive (IENaC) but not cAMP-activated Cl(-) currents across confluent monolayers of rat ATII, and mouse nasal epithelial cells grew in primary culture by 45 and 25%, respectively. Changes in IENaC by I?I in ATII cells were accompanied by increased levels of uncleaved (immature) surface ?-ENaC. I?I increased airway surface liquid depth overlying murine nasal epithelial cells to the same extent as amiloride, consistent with ENaC inhibition. Incubation of lung slices from C57BL/6, those lacking phenylalanine at position 508 (?F508), or CF transmembrane conductance regulator knockout mice with I?I for 3 hours decreased the open probability of their ENaC channels by 50%. ?F508 mice had considerably higher levels the amiloride-sensitive fractions of ENaC nasal potential difference (ENaC-NPD) than wild-type littermates and only background levels of I?I in their BALF. A single intranasal instillation of I?I decreased their ENaC-NPD 24 hours later by 25%. In conclusion, we show that I?I is present in the BALF of children with CF, is an effective inhibitor of ENaC proteolysis, and decreases ENaC activity in lung epithelial cells of ?F508 mice. PMID:24303840

  1. Naturally Occurring Incompatibilities between Different Culex pipiens pallens Populations as the Basis of Potential Mosquito Control Measures

    PubMed Central

    Chen, Lin; Zhu, Changliang; Zhang, Donghui

    2013-01-01

    Background Vector-borne diseases remain a threat to public health, especially in tropical countries. The incompatible insect technique has been explored as a potential control strategy for several important insect vectors. However, this strategy has not been tested in Culex pipiens pallens, the most prevalent mosquito species in China. Previous works used introgression to generate new strains that matched the genetic backgrounds of target populations while harboring a new Wolbachia endosymbiont, resulting in mating competitiveness and cytoplasmic incompatibility. The generation of these incompatible insects is often time-consuming, and the long-term stability of the newly created insect-Wolbachia symbiosis is uncertain. Considering the wide distribution of Cx. pipiens pallens and hence possible isolation of different populations, we sought to test for incompatibilities between natural populations and the possibility of exploiting these incompatibilities as a control strategy. Methodology/Principal Findings Three field populations were collected from three geographic locations in eastern China. Reciprocal cross results showed that bi-directional patterns of incompatibility existed between some populations. Mating competition experiments indicated that incompatible males could compete with cognate males in mating with females, leading to reduced overall fecundity. F1 offspring from incompatible crosses maintained their maternal crossing types. All three populations tested positive for Wolbachia. Removal of Wolbachia by tetracycline rendered matings between these populations fully compatible. Conclusions/Significance Our findings indicate that naturally occurring patterns of cytoplasmic incompatibility between Cx. pipiens pallens populations can be the basis of a control strategy for this important vector species. The observed incompatibilities are caused by Wolbachia. More tests including field trials are warranted to evaluate the feasibility of this strategy as a supplement to other control measures. PMID:23383354

  2. Why do phytoplankton species composition and “traditional” water quality parameters indicate different ecological status of a large shallow lake?

    Microsoft Academic Search

    Lea Tuvikene; Tiina Nõges; Peeter Nõges

    2011-01-01

    Long-term data on phytoplankton species composition in large and shallow Lake Võrtsjärv indicated a sharp deterioration of\\u000a the ecological status at the end of the 1970s. The more traditional water quality indicators, such as the concentrations of\\u000a nutrients and chlorophyll a, phytoplankton biomass, and Secchi depth, failed to capture this tipping point or even showed\\u000a an improvement of the status

  3. Perylene/water clusters: some different trends in hydrogen-bonded structure induced by a large aromatic template

    NASA Astrophysics Data System (ADS)

    Palmer, Phillip M.; Chen, Yu; Topp, Michael R.

    2000-08-01

    Measurements are reported of infrared-optical double-resonance spectra (3100-3800 cm -1) for jet-cooled perylene/(H 2O) n clusters ranging up to n=8. Unusual patterns of OH-stretch resonances, which are particularly evident for the n=3-6 clusters, imply that some significant structural perturbations are taking place in the presence of the large aromatic molecule.

  4. Morphological and Metabolic Changes Associated with Large Differences in Daily Food Intake in Crossed-Intestines Rats

    Microsoft Academic Search

    Henry S Koopmans; Thomas J McDonald; Mario Digirolamo

    1997-01-01

    Koopmans, H. S., T. J. McDonald and M. DiGirolamo. Morphological and metabolic changes associated with large changes in food intake in crossed-intestines rats. Physiol Behav 62(1) 129–136, 1997.—Twenty-two inbred male Lewis rats were made into parabiotic pairs and 7 pairs had a further operation in which the small intestines of the 2 rats were connected so that one rat continually

  5. Applying different methods to evaluate the freshness of large yellow croacker (Pseudosciaena crocea) fillets during chilled storage.

    PubMed

    Zhao, Jin; Li, Jianrong; Wang, Jinlin; Lv, Weijin

    2012-11-14

    The freshness of large yellow croaker ( Pseudosciaena crocea ) fillets was evaluated over 20 days of chilled storage under vacuum packaging. The physicochemical properties [pH, K value, thiobarbituric acid (TBA), texture profile analyses (TPA), color], microbiological properties [total viable count (TVC)], sensory attributes, transcriptomics (levels of transcripts coding for cathepsin L), and functional properties of proteins [emulsion activity (EA) and emulsion stability (ES)] were assessed at 0, 5, 10, 15, and 20 days of storage. This study also investigated the effect of the storage time on fish muscle proteome in large yellow croaker using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometry (MALDI-TOF-MS/MS). The parameters that were the most sensitive to storage duration were color (C*(ab)), TPA (springiness, chewiness, and resilience), pH, K value, TVC, levels of transcripts coding for cathepsin L, EA, ES, and sensory attributes. The three altered proteins were successfully identified. Therefore, these parameters might be considered suitable indicators for evaluating the freshness of large yellow croaker fillets during chilled storage under vacuum packaging. PMID:23095034

  6. 336 Brazilian Journal of Physics, vol. 36, no. 2A, June, 2006 Magnetotransport in AlxGax-1As Quantum Wells with Different Potential Shapes

    E-print Network

    Gusev, Guennady

    Quantum Wells with Different Potential Shapes N. C. Mamani, C. A. Duarte, G. M. Gusev, A. A. Quivy, and T quantum wells. We calculate the transport mobility for electrons belonging to the different subbands. We with our calculations. Keywords: AlxGax-1As; Transport properties; Quantum wells I. INTRODUCTION Recent

  7. A Review of Sex Differences in Peer Relationship Processes: Potential Trade-offs for the Emotional and Behavioral Development of Girls and Boys

    Microsoft Academic Search

    Amanda J. Rose; Karen D. Rudolph

    2006-01-01

    Theory and research on sex differences in adjustment focus largely on parental, societal, and biological influences. However, it also is important to consider how peers contribute to girls' and boys' development. This article provides a critical review of sex differences in several peer relationship processes, including behavioral and social-cognitive styles, stress and coping, and relationship provisions. The authors present a

  8. A Review of Sex Differences in Peer Relationship Processes: Potential Trade-Offs for the Emotional and Behavioral Development of Girls and Boys

    ERIC Educational Resources Information Center

    Rose, Amanda J.; Rudolph, Karen D.

    2006-01-01

    Theory and research on sex differences in adjustment focus largely on parental, societal, and biological influences. However, it also is important to consider how peers contribute to girls' and boys' development. This article provides a critical review of sex differences in several peer relationship processes, including behavioral and…

  9. Single particle calculations for a Woods Saxon potential with triaxial deformations, and large Cartesian oscillator basis (new version code)

    NASA Astrophysics Data System (ADS)

    Mohammed-Azizi, B.; Medjadi, D. E.

    2007-05-01

    We present a new version of the computer program which solves the Schrödinger equation of the stationary states for an average nuclear potential of Woods-Saxon type. In this work, we take specifically into account triaxial (i.e. ellipsoidal) nuclear surfaces. The deformation is specified by the usual Bohr parameters. The calculations are carried out in two stages. In the first, one calculates the representative matrix of the Hamiltonian in the Cartesian oscillator basis. In the second stage one diagonalizes this matrix with the help of subroutines of the EISPACK library. This new version calculates all the eigenvalues up to a given cutoff energy, and gives the components of the corresponding eigenfunctions. For a more convenient handling, these results are stored simultaneously in the computer memory, and on a files. Program summaryTitle of program:Triaxial2007 Catalogue identifier:ADSK_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADSK_v2_0 Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Summary of revision:One input file instead two. Reduced number of input parameters. Storage of eigenvalues and eigenvectors in memory in a very simple way which makes the code very convenient to the user. Reasons for the new version: More convenient handling of the eigenvectors Catalogue number old version: ADSK Catalogue number new version:ADSK_v2_0 Journal: Computer Physics Commun. 156 (2004) 241-282 Licensing provisions: none Computer: PC Pentium 4, 2600 MHz Hard disk: 40 Gb RAM: 256 Mb Swap file: 4 Gb Operating system: WINDOWS XP Software used: Compaq Visual FORTRAN (with full optimizations in the settings project options) Programming language used:Fortran 77/90 (double precision) Number of bits in a word: 32 No. of lines in distributed program, including test data, etc.:4058 No. of bytes in distributed program, including test data, etc.:75 590 Distribution format:tar.gz Nature of the problem: The single particle energies and the single particle wave functions are calculated from one-body Hamiltonian including a central field of Woods-Saxon type, a spin-orbit interaction, and the Coulomb potential for the protons. We consider only ellipsoidal (triaxial) shapes. The deformation of the nuclear shape is fixed by the usual Bohr parameters (?,?). Method of solution: The representative matrix of the Hamiltonian is built by means of the Cartesian basis of the anisotropic harmonic oscillator, and then diagonalized by a set of subroutines of the EISPACK library. Two quadrature methods of Gauss are employed to calculate, respectively, the integrals of the matrix elements of the Hamiltonian, and the integral defining the Coulomb potential. Restrictions: There are two restrictions for the code: The number of the major shells of the basis does not have to exceed N=26. For the largest values of N (˜23-26), the diagonalization takes the major part of the running time, but the global run-time remains reasonable. Typical running time: (With full optimization in the project settings of the Compaq Visual Fortran on Windows XP) With N=23, for the neutrons case, and for both parities, the running time is about 40 sec on the P4 computer at 2.6 GHz. In this case, the calculation of the matrix elements takes only about 17 sec. If all unbound states are required, the runtime becomes larger.

  10. Single particle calculations for a Woods-Saxon potential with triaxial deformations, and large Cartesian oscillator basis

    NASA Astrophysics Data System (ADS)

    Mohammed-Azizi, B.; Medjadi, D. E.

    2004-01-01

    We present a computer program which solves the Schrodinger equation of the stationary states for an average nuclear potential of Woods-Saxon type. In this work, we take specifically into account triaxial (i.e. ellipsoidal) nuclear surfaces. The deformation is specified by the usual Bohr parameters. The calculations are carried out in two stages. In the first, one calculates the representative matrix of the Hamiltonian in the Cartesian oscillator basis. In the second stage one diagonalizes this matrix with the help of subroutines of the Eispack library. If it is wished, one can calculate all eigenvalues, or only the part of the eigenvalues that are contained in a fixed interval defined in advance. In this latter case the eigenvectors are given conjointly. The program is very rapid, and the run-time is mainly used for the diagonalization. Thus, it is possible to use a significant number of the basis states in order to insure a best convergence of the results. Program summaryProgram obtainable from:CPC Program Library, Queen's University of Belfast, N. Ireland Title of program:Triaxial Catalogue number:ADSK Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADSK Licensing provisions:None Computer:PC. AMD Athlon 1000 MHz Hard disk:40 Go Ram:256 Mo Swap file:4 Go Operating system:WINDOWS XP Software used:Microsoft Visual Fortran 5.0A (with full optimizations in the settings project options) Programming language:Fortran 77/90 (double precision) Number of bits in a word:32 Number of lines:7662 No. of bytes in distributed program, including test data, etc.:174 601 Distribution format:tar gzip file Nature of the problem: The single particle energies and the single particle wave functions are calculated from one-body Hamiltonian including a central field of Woods-Saxon type, a spin-orbit interaction, and the Coulomb potential for the protons. We consider only ellipsoidal (triaxial) shapes. The deformation of the nuclear shape is fixed by the usual Bohr parameters ( ?, ?). Method of solution: The representative matrix of the Hamiltonian is built by means of the Cartesian basis of the anisotropic harmonic oscillator, and then diagonalized by a set of subroutines of the Eispack library. Two quadrature methods of Gauss are employed to calculate respectively the integrals of the matrix elements of the Hamiltonian, and the integral defining the Coulomb potential. Restrictions: There are two restrictions for the code: The number of the major shells of the basis does not have to exceed Nmax=26. For the largest values of Nmax (˜23-26), the diagonalization takes the major part of the running time, but the global run-time remains reasonable. Typical running time: (With full optimization in the project settings of the Microsoft Visual Fortran 5.0A on Windows XP.) With Nmax=23, for the neutrons case, and for both parities, if we need all eigenenergies and all eigenfunctions of the bound states, the running time is about 80 sec on the AMD Athlon computer at 1 GHz. In this case, the calculation of the matrix elements takes only about 20 sec. If all unbound states are required, the runtime becomes larger.

  11. BK and Kv3.1 potassium channels control different aspects of deep cerebellar nuclear neurons action potentials and spiking activity.

    PubMed

    Pedroarena, Christine M

    2011-12-01

    Deep cerebellar nuclear neurons (DCNs) display characteristic electrical properties, including spontaneous spiking and the ability to discharge narrow spikes at high frequency. These properties are thought to be relevant to processing inhibitory Purkinje cell input and transferring well-timed signals to cerebellar targets. Yet, the underlying ionic mechanisms are not completely understood. BK and Kv3.1 potassium channels subserve similar functions in spike repolarization and fast firing in many neurons and are both highly expressed in DCNs. Here, their role in the abovementioned spiking characteristics was addressed using whole-cell recordings of large and small putative-glutamatergic DCNs. Selective BK channel block depolarized DCNs of both groups and increased spontaneous firing rate but scarcely affected evoked activity. After adjusting the membrane potential to control levels, the spike waveforms under BK channel block were indistinguishable from control ones, indicating no significant BK channel involvement in spike repolarization. The increased firing rate suggests that lack of DCN-BK channels may have contributed to the ataxic phenotype previously found in BK channel-deficient mice. On the other hand, block of Kv3.1 channels with low doses of 4-aminopyridine (20 ?M) hindered spike repolarization and severely depressed evoked fast firing. Therefore, I propose that despite similar characteristics of BK and Kv3.1 channels, they play different roles in DCNs: BK channels control almost exclusively spontaneous firing rate, whereas DCN-Kv3.1 channels dominate the spike repolarization and enable fast firing. Interestingly, after Kv3.1 channel block, BK channels gained a role in spike repolarization, demonstrating how the different function of each of the two channels is determined in part by their co-expression and interplay. PMID:21750937

  12. The potential of large germanium detector arrays for solar-axion searches utilizing the axio-electric effect for detection

    E-print Network

    F. T. Avignone III

    2009-02-02

    The sensitivities of large arrays of low-background germanium detectors for solar axion searches are investigated in the context of three coupling scenarios. A search was made for the 14.4-keV axion branch from the M1-transition in the thermally excited 57Fe in the solar core in 80 kgd of data from the IGEX Dark Matter experiment published earlier. In one scenario, the direct couplings of axions to hadrons and to electrons were assumed to be in the range of Peccei-Quinn (PQ) scale, 3x105 GeV < fPQ < 7x105 GeV. This scenario is excluded by the IGEX data. In a second case, at the same PQ scale, coupling to photons and to electrons are suppressed. The IGEX data partially excludes this scenario depending on the degree of suppression. In the third case, the PQ-scale for all couplings is assumed to be in the range: 3x106 GeV< fPQ <7x106 GeV. Detection rates in Ge for all three scenarios are presented.

  13. Genetically distant American Canine distemper virus lineages have recently caused epizootics with somewhat different characteristics in raccoons living around a large suburban zoo in the USA

    Microsoft Academic Search

    John A Lednicky; Jean Dubach; Michael J Kinsel; Thomas P Meehan; Maurizio Bocchetta; Laura L Hungerford; Nicolene A Sarich; Kelley E Witecki; Michael D Braid; Casandra Pedrak; Christiane M Houde

    2004-01-01

    BACKGROUND: Mortality rates have differed during distemper outbreaks among free-ranging raccoons (Procyon lotor) living around a large Chicago-area zoo, and appeared higher in year 2001 than in 1998 and 2000. We hypothesized that a more lethal variant of the local Canine distemper virus (CDV) lineage had emerged in 2001, and sought the genetic basis that led to increased virulence. However,

  14. Differences in Adipocytokines and Fatty Acid Composition between Two Adipocyte Fractions of Small and Large Cells in High-Fat Diet-Induced Obese Mice

    Microsoft Academic Search

    Yoshiyuki Matsubara; Koichiro Kano; Daisuke Kondo; Hideo Mugishima; Taro Matsumoto

    2009-01-01

    Objective: This study was conducted to compare the differences in adipocytokines and fatty acid composition between two fraction sizes of small and large cells from subcutaneous and visceral fat of mice receiving a high-fat diet (HFD). Methods: Body weight, blood glucose and cholesterol levels, and adipocyte diameter distribution were examined. Total adipocyte fractions could be separated into the small-cell fraction

  15. Different methanotrophic potentials in stratified polar fjord waters (Storfjorden, Spitsbergen) identified by using a combination of methane oxidation techniques

    NASA Astrophysics Data System (ADS)

    Mau, S.; Blees, J.; Helmke, E.; Niemann, H.; Damm, E.

    2013-04-01

    The bacterially mediated aerobic methane oxidation (MOx) is a key mechanism in controlling methane (CH4) emissions from the world's oceans to the atmosphere. In this study, we investigated MOx in the Arctic fjord Storfjorden (Spitsbergen) by applying a combination of radio-tracer based incubation assays (3H-CH4 and 14H-CH4), stable C-CH4 isotope measurements, and molecular tools (16S rRNA DGGE-fingerprinting, pmoA- and mxaF gene analyses). Strofjorden is stratified in the summertime with melt water (MW) in the upper 60 m of the water column, Arctic water (ArW) between 60-100 m and brine-enriched shelf water (BSW) down to 140 m. CH4 concentrations were supersaturated with respect to the atmospheric equilibrium (∼3 nM) throughout the water column, increasing from ∼20 nM at the surface to a maximum of 72 nM at 60 m and decreasing below. MOx rate measurements at near in situ CH4 concentrations (here measured with 3H-CH4 raising the ambient CH4 pool by <2 nM) showed a similar trend: low rates at the sea surface increasing to a maximum of ∼2.3 nM d-1 at 60 m followed by a decrease in the deeper ArW/BSW. In contrast, rate measurements with 14H-CH4 at elevated CH4 concentrations (incubations were spiked with ∼450 nM of 14H-CH4, providing an estimate of the CH4 oxidation potential) showed comparably low turnover rates (<1 nMd-1) at 60 m, but peaked in ArW/BSW at ∼100 m water depth, concomitant with increasing 14C-values in the residual CH4 pool. Our results indicate that the MOx community in the surface MW is adapted to relatively low CH4 concentrations. In contrast, the activity of the deep water MOx community is relatively low at the ambient, summertime CH4 concentrations but has the potential to increase rapidly in response to CH4 availability. A similar distinction between surface and deep water MOx is also suggested by our molecular analyses. Although, we found pmoA and maxF gene sequences throughout the water column attesting the ubiquitous presence of MOx communities in Storfjorden, deep water amplicons of pmoA and maxF were unusually long. Also a DGGE band related to the known Type I MOx Mehtylosphera was observed in deep BWS, but absent in surface MW. Apparently, different MOx communities have developed in the stratified water masses in Storfjorden, which is possibly related to the spatiotemporal variability in CH4 supply to the distinct water masses.

  16. The VOLTAIRE 2002 cruise: a high resolution MCS survey of large potential tsunamigenic structures off SW Iberia

    NASA Astrophysics Data System (ADS)

    Rovere, M.; Zitellini, N.; Matias, L.; Voltaire Shipboard Party

    2003-04-01

    During November-December 2002 the marine geophysical survey VOLTAIRE (Valuation Of Large Tsunami And Iberian Risk for Earthquakes) has been carried out offshore the SW corner of the Iberian Peninsula. The multi-channel seismic campaign has been supported by the cooperative effort of Italian funding Agencies and the Portuguese MATESPRO project. The campaign is a further step within a wider and firm collaboration among several European Institutions for the study of the area off the SW Iberian Peninsula and NW Morocco. The area encompasses the plate boundary between the Eurasian and African plates, it is characterised by a relevant seismic activity, complicated tectonics and diffuse compressional deformation as testified by scattered seismicity. The main goal of the survey VOLTAIRE was the study of the active tectonic processes at the continental margins of SW Iberia, that give rise to a high concentration of natural hazards associated with seismicity, tsunami generation and large submarine mass wasting. During the VOLTAIRE survey we have focused the investigation upon three main topics: 1. the shallow deformation occurring at the Guadalquivir Bank; 2. the lateral extent of some active thrust faults located in the Horseshoe Abyssal Plain; 3. the study of the south-eastern tectonic termination of the sub-marine hill Marquês de Pombal. All these structures are associated with clusters of current seismicity. The Guadalquivir Bank is a structural sub-marine high, E-W oriented, which represents the seaward prolongation of the Hercynian Iberian massif. The Horseshoe fault is a NE-SW oriented feature, with a fault displacement increasing from south to north. The location of the Horseshoe fault lies in proximity to the epicenter of the 1969's Lisbon earthquake. The Marquês de Pombal has been the subject of several recent high-resolution investigations: the BIGSETS EU-project (Zitellini et al., 2001), one leg of the TTR-10 cruise (Terrinha et al., in press), the Parsifal and HITS cruises (Gràcia et al., in press). All these studies confirmed that the Marquês de Pombal is the probable source of the hystorical 1755's Lisbon tsunami-earthquake. These new MCS profiles complement the preexisting data set in the area allowing the detailed study of the geometry of the faults related to the above mentioned regional tectonic structures. The accurate knowledge of the geology of these structures, coupled with a constant monitoring of the regional seismicity, will contribute in assessing their potenzial hazard on the coasts of SW Portugal and NW Morocco. References Gràcia, E. et al. (2002). Mapping active faults offshore Portugal (36N-38N): Implications for seismic hazard assessment along the southwest Iberian Margin. Geology (in press). Terrinha, P. et al. (2002). Tsunamigenic-seismogenic structures, neotectonics, sedimentary processes and slope instability on the southwest Portuguese margin. Marine Geology (in press). Zitellini, N. et al. (2001). The 1755 Lisbon earthquake and Tsunami: localization and investigation of the possible tectonic source. EOS Transactions, 82, 26, 285-291.

  17. Future changes of wind energy potentials over Europe in a large CMIP5 multi-model ensemble

    NASA Astrophysics Data System (ADS)

    Reyers, Mark; Moemken, Julia; Pinto, Joaquim G.

    2015-04-01

    A statistical-dynamical downscaling method is used to estimate future changes of wind energy output (Eout) of an idealized wind turbine across Europe at the regional scale. With this aim, 22 GCMs of the CMIP5 ensemble are considered. The downscaling method uses circulation weather types and regional climate modelling with the COSMO-CLM model. Future projections are computed for two time periods (2021-2060 and 2061-2100) following two scenarios (RCP4.5 and RCP8.5). The CMIP5 ensemble mean response reveal a more likely than not increase of mean annual Eout over Northern and Central Europe and a likely decrease over Southern Europe. There is some uncertainty with respect to the magnitude and the sign of the changes. Higher robustness in future changes is observed for specific seasons. Except from the Mediterranean area, an ensemble mean increase of Eout is simulated for winter and a decreasing for the summer season, resulting in a strong increase of the intra-annual variability for most of Europe. The latter is in particular likely during the 2nd half of the 21st century under the RCP8.5 scenario. In general, signals are stronger for 2061-2100 compared to 2021-2060 and for RCP8.5 compared to RCP4.5. Regarding changes of the inter-annual variability of Eout for Central Europe, the future projections strongly vary between individual models and also between future periods and scenarios within single models. This study showed for an ensemble of 22 CMIP5 models that changes in the wind energy potentials over Europe may take place in future decades. However, due to the uncertainties detected in this research, further investigations with multi-model ensembles are needed to provide a better quantification and understanding of the future changes.

  18. Radiative Corrections to the Inflaton Potential as an Explanation of Suppressed Large Scale Power in Density Perturbations and the Cosmic Microwave Background

    E-print Network

    A. Buchel; F. A. Chishtie; V. Elias; Katherine Freese; R. B. Mann; D. G. C. McKeon; T. G. Steele

    2005-03-03

    The Wilkinson Microwave Anisotropy Probe microwave background data suggest that the primordial spectrum of scalar curvature fluctuations is suppressed at small wavenumbers. We propose a UV/IR mixing effect in small-field inflationary models that can explain the observable deviation in WMAP data from the concordance model. Specifically, in inflationary models where the inflaton couples to an asymptotically free gauge theory, the radiative corrections to the effective inflaton potential can be anomalously large. This occurs for small values of the inflaton field which are of the order of the gauge theory strong coupling scale. Radiative corrections cause the inflaton potential to blow up at small values of the inflaton field. As a result, these corrections can violate the slow-roll condition at the initial stage of the inflation and suppress the production of scalar density perturbations.

  19. Efficacy of very fast simulated annealing global optimization method for interpretation of self-potential anomaly by different forward formulation over 2D inclined sheet type structure

    NASA Astrophysics Data System (ADS)

    Biswas, A.; Sharma, S. P.

    2012-12-01

    Self-Potential anomaly is an important geophysical technique that measures the electrical potential due natural source of current in the Earth's subsurface. An inclined sheet type model is a very familiar structure associated with mineralization, fault plane, groundwater flow and many other geological features which exhibits self potential anomaly. A number of linearized and global inversion approaches have been developed for the interpretation of SP anomaly over different structures for various purposes. Mathematical expression to compute the forward response over a two-dimensional dipping sheet type structures can be described in three different ways using five variables in each case. Complexities in the inversion using three different forward approaches are different. Interpretation of self-potential anomaly using very fast simulated annealing global optimization has been developed in the present study which yielded a new insight about the uncertainty and equivalence in model parameters. Interpretation of the measured data yields the location of the causative body, depth to the top, extension, dip and quality of the causative body. In the present study, a comparative performance of three different forward approaches in the interpretation of self-potential anomaly is performed to assess the efficacy of the each approach in resolving the possible ambiguity. Even though each forward formulation yields the same forward response but optimization of different sets of variable using different forward problems poses different kinds of ambiguity in the interpretation. Performance of the three approaches in optimization has been compared and it is observed that out of three methods, one approach is best and suitable for this kind of study. Our VFSA approach has been tested on synthetic, noisy and field data for three different methods to show the efficacy and suitability of the best method. It is important to use the forward problem in the optimization that yields the best result without any ambiguity and smaller uncertainty. Keywords: SP anomaly, inclined sheet, 2D structure, forward problems, VFSA Optimization,

  20. Identifying the differences in survivorship and growth in offspring of large and small females in the pipefish species Syngnathus scovelli 

    E-print Network

    Martinez Aguirre, Andrea

    2014-12-15

    have looked at egg size and components of an egg’s makeup as indicators of offspring quality and have found conflicting results. In this study, we compared growth and survivorship of offspring from females of different sizes by mating a controlled sized...

  1. Variations of surface water extent and water storage in large river basins: A comparison of different global data sources

    E-print Network

    water is stored, surface waters comprised of rivers, lakes, man-made reservoirs, wetlands a primary role in the global water cycle and climate. Among the different reservoirs in which terrestrial, evaporation, infiltration, and runoff, are still not well-known [Bullock and Acreman, 2003]. Lacking spatially

  2. Estimating the Percentage of the Population With Abnormally Low Scores (or Abnormally Large Score Differences) on Standardized

    E-print Network

    Crawford, John R.

    Differences) on Standardized Neuropsychological Test Batteries: A Generic Method With Applications John R) is fundamental in interpreting the results of a neuropsychological assessment. If a standardized battery of tests available. Keywords: neuropsychological assessment, multiple tests, single-case inference, Monte Carlo

  3. The v4 large-amplitude bending potential of HNCO as determined by a semirigid bender analysis of the ground state rotational spectra

    NASA Astrophysics Data System (ADS)

    Niedenhoff, Marion; Yamada, Koichi M. T.; Winnewisser, Gisbert; Ross, Stephen C.

    1995-06-01

    The ground state microwave, millimeter wave, and far-infrared spectroscopic data ( J < 10) of HNCO and its isotopomers were analyzed using the semirigid bender (SRB) Hamiltonian. The geometry of the molecule and the potential energy function of the large-amplitude HNC-bending motion were determined by a non-linear least-squares fitting procedure. The barrier to the linear configuration was found to be 1899 cm -1, which is much lower than the previously reported value. The parameters determined for the molecular structure are in excellent agreement with the rs values.

  4. On the use of big-bang method to generate low-energy structures of atomic clusters modeled with pair potentials of different ranges.

    PubMed

    Marques, J M C; Pais, A A C C; Abreu, P E

    2012-02-01

    The efficiency of the so-called big-bang method for the optimization of atomic clusters is analysed in detail for Morse pair potentials with different ranges; here, we have used Morse potentials with four different ranges, from long- ? = 3) to short-ranged ? = 14) interactions. Specifically, we study the efficacy of the method in discovering low-energy structures, including the putative global minimum, as a function of the potential range and the cluster size. A new global minimum structure for long-ranged ? = 3) Morse potential at the cluster size of n= 240 is reported. The present results are useful to assess the maximum cluster size for each type of interaction where the global minimum can be discovered with a limited number of big-bang trials. PMID:22131287

  5. Gender differences in the mathematics achievements of German primary school students: results from a German large-scale study

    Microsoft Academic Search

    Henrik Winkelmann; Marja van den Heuvel-Panhuizen; Alexander Robitzsch

    2008-01-01

    In Germany, national standards for mathematics for the end of primary school were established in 2004. In the present study,\\u000a data were collected to evaluate these standards, and were used to compare the mathematical skills of girls and boys. Many\\u000a studies have shown that gender differences are strongest at the highest levels of education. The findings from primary school\\u000a are

  6. DOES ALCOHOLICS ANONYMOUS WORK DIFFERENTLY FOR MEN AND WOMEN? A MODERATED MULTIPLE-MEDIATION ANALYSIS IN A LARGE CLINICAL SAMPLE

    PubMed Central

    Kelly, John F.; Hoeppner, Bettina B.

    2012-01-01

    Background Alcoholics Anonymous (AA) began as a male organization, but about one third is now female. Studies have found that women participate at least as much as men and benefit equally from AA, but it is unclear whether women benefit from AA in the same or different ways as men. This study tested whether gender moderated the mechanisms through which AA aids recovery. Methods A cohort study of alcohol dependent adults (N=1,726; 24% female; Project MATCH) was assessed on AA attendance during treatment; with mediators at 9 months; outcomes (Percent Days Abstinent [PDA] and Drinks per Drinking Day [DDD]) at 15 months. Multiple mediator models tested whether purported mechanisms (i.e., self-efficacy, depression, social networks, spirituality/religiosity) explained AA's effects differently for men and women controlling for baseline values, mediators, treatment, and other confounders. Results For PDA, the proportion of AA's effect accounted for by the mediators was similar for men (53%) and women (49%). Both men and women were found to benefit from changes in social factors but these mechanisms were more important among men. For DDD, the mediators accounted for 70% of the effect of AA for men and 41% for women. Again, men benefitted mostly from social changes. Independent of AA's effects, negative affect self-efficacy was shown to have a strong relationship to outcome for women but not men. Conclusions The recovery benefits derived from AA differ in nature and magnitude between men and women and may reflect differing needs based on recovery challenges related to gender-based social roles and drinking contexts. PMID:23206376

  7. Large-scale relocation of two decades of Northern California seismicity using cross-correlation and double-difference methods

    Microsoft Academic Search

    Felix Waldhauser; David P. Schaff

    2008-01-01

    We simultaneously reanalyzed two decades (1984-2003) of the digital seismic archive of Northern California using waveform cross-correlation (CC) and double-difference (DD) methods to improve the resolution in hypocenter locations in the existing earthquake catalog generated at the Northern California Seismic Network (NCSN) by up to three orders of magnitude. We used a combination of ~3 billion CC differential times measured

  8. Large-scale relocation of two decades of Northern California seismicity using cross-correlation and double-difference methods

    Microsoft Academic Search

    Felix Waldhauser; David P. Schaff

    2008-01-01

    We simultaneously reanalyzed two decades (1984–2003) of the digital seismic archive of Northern California using waveform cross-correlation (CC) and double-difference (DD) methods to improve the resolution in hypocenter locations in the existing earthquake catalog generated at the Northern California Seismic Network (NCSN) by up to three orders of magnitude. We used a combination of ?3 billion CC differential times measured

  9. Interspecies Avian Brain Chimeras Reveal That Large Brain Size Differences Are Influenced by Cell–Interdependent Processes

    PubMed Central

    Chen, Chun-Chun; Balaban, Evan; Jarvis, Erich D.

    2012-01-01

    Like humans, birds that exhibit vocal learning have relatively delayed telencephalon maturation, resulting in a disproportionately smaller brain prenatally but enlarged telencephalon in adulthood relative to vocal non-learning birds. To determine if this size difference results from evolutionary changes in cell-autonomous or cell-interdependent developmental processes, we transplanted telencephala from zebra finch donors (a vocal-learning species) into Japanese quail hosts (a vocal non-learning species) during the early neural tube stage (day 2 of incubation), and harvested the chimeras at later embryonic stages (between 9–12 days of incubation). The donor and host tissues fused well with each other, with known major fiber pathways connecting the zebra finch and quail parts of the brain. However, the overall sizes of chimeric finch telencephala were larger than non-transplanted finch telencephala at the same developmental stages, even though the proportional sizes of telencephalic subregions and fiber tracts were similar to normal finches. There were no significant changes in the size of chimeric quail host midbrains, even though they were innervated by the physically smaller zebra finch brain, including the smaller retinae of the finch eyes. Chimeric zebra finch telencephala had a decreased cell density relative to normal finches. However, cell nucleus size differences between each species were maintained as in normal birds. These results suggest that telencephalic size development is partially cell-interdependent, and that the mechanisms controlling the size of different brain regions may be functionally independent. PMID:22860132

  10. Hole-transport materials with greatly-differing redox potentials give efficient TiO2-[CH3NH3][PbX3] perovskite solar cells.

    PubMed

    Abate, Antonio; Planells, Miquel; Hollman, Derek J; Barthi, Vishal; Chand, Suresh; Snaith, Henry J; Robertson, Neil

    2015-01-28

    Two diacetylide-triphenylamine hole-transport materials (HTM) with varying redox potential have been applied in planar junction TiO2-[CH3NH3]PbI3-xClx solar cells leading to high power-conversion efficiencies up to 8.8%. More positive oxidation potential of the HTM gives higher VOC and lower JSC illustrating the role of matching energy levels, however both HTMs gave efficient cells despite a difference of 0.44 V in their redox potentials. PMID:25504144

  11. Examining different measures of multimorbidity, using a large prospective cross-sectional study in Australian general practice

    PubMed Central

    Harrison, Christopher; Britt, Helena; Miller, Graeme; Henderson, Joan

    2014-01-01

    Objectives Prevalence estimates of multimorbidity vary widely due to inconsistent definitions and measurement methods. This study examines the independent effects on prevalence estimates of how ‘disease entity’ is defined—as a single chronic condition or chapters/domains in the International Classification of Primary Care (V.2; ICPC-2), International Classification of Disease (10th revision; ICD-10) or the Cumulative Illness Rating Scale (CIRS), the number of disease entities required for multimorbidity, and the number of chronic conditions studied. Design National prospective cross-sectional study. Setting Australian general practice. Participants 8707 random consenting deidentified patient encounters with 290 randomly selected general practitioners. Main outcome measures Prevalence estimates of multimorbidity using different definitions. Results Data classified to ICPC-2 chapters, ICD-10 chapters or CIRS domains produce similar multimorbidity prevalence estimates. When multimorbidity was defined as two or more (2+) disease entities: counting individual chronic conditions and groups of chronic conditions produced similar estimates; the 12 most prevalent chronic conditions identified about 80% of those identified using all chronic conditions. When multimorbidity was defined as 3+ disease entities: counting individual chronic conditions produced significantly higher estimates than counting groups of chronic conditions; the 12 most prevalent chronic conditions identified only two-thirds of patients identified using all chronic conditions. Conclusions Multimorbidity defined as 2+ disease entities can be measured using different definitions of disease entity with as few as 12 prevalent chronic conditions, but lacks specificity to be useful, especially in older people. Multimorbidity, defined as 3+, requires more measurement conformity and inclusion of all chronic conditions, but provides greater specificity than the 2+ definition. The proposed concept of “complex multimorbidity”, the co-occurrence of three or more chronic conditions affecting three or more different body systems within one person without defining an index chronic condition, may be useful in identifying high-need individuals. PMID:25015470

  12. Low temperature aging mechanism identification and lithium deposition in a large format lithium iron phosphate battery for different charge profiles

    NASA Astrophysics Data System (ADS)

    Ouyang, Minggao; Chu, Zhengyu; Lu, Languang; Li, Jianqiu; Han, Xuebing; Feng, Xuning; Liu, Guangming

    2015-07-01

    Charging procedures at low temperatures severely shorten the cycle life of lithium ion batteries due to lithium deposition on the negative electrode. In this paper, cycle life tests are conducted to reveal the influence of the charging current rate and the cut-off voltage limit on the aging mechanisms of a large format LiFePO4 battery at a low temperature (-10 °C). The capacity degradation rates accelerate rapidly after the charging current reaches 0.25 C or the cut-off voltage reaches 3.55 V. Therefore the scheduled current and voltage during low-temperature charging should be reconsidered to avoid capacity degradation. Lithium deposition contributes to low-temperature aging mechanisms, as something needle-like which might be deposited lithium is observed on the surface of the negative electrode after disassembling the aged battery cell. To confirm our explanation, incremental capacity analysis (ICA) is performed to identify the characteristics of the lithium deposition induced battery aging mechanisms. Furthermore, the aging mechanism is quantified using a mechanistic model, whose parameters are estimated with the particle swarm optimization algorithm (PSO). The loss of reversible lithium originating from secondary SEI formation and dead lithium is confirmed as the cause of the aging.

  13. MEASUREMENT OF THE HIGH-FIELD Q-DROP IN A LARGE-GRAIN NIOBIUM CAVITY FOR DIFFERENT OXIDATION PROCESSES

    SciTech Connect

    Gianluigi Ciovati; Peter Kneisel; Alex Gurevich

    2008-01-23

    In this contribution, we present the results from a series of RF tests at 1.7 K and 2.0 K on a single-cell cavity made of high-purity large (with area of the order of few cm2) grain niobium which underwent various oxidation processes. After initial buffered chemical polishing, anodization, baking in pure oxygen atmosphere and baking in air up to 180 °C was applied with the objective of clearly identifying the role of oxygen and the oxide layer on the Q-drop. During each rf test a temperature mapping system was used allowing to measure the local temperature rise of the cavity outer surface due to RF losses, which gives information about the losses location, their field dependence and space distribution on the RF surface. The results confirmed that the depth affected by baking is about 20 – 30 nm from the surface and showed that the Q-drop did not re-appear in a previously baked cavity by further baking at 120 °C in pure oxygen atmosphere or in air up to 180 °C. A statistic of the position of the “hot-spots” on the cavity surface showed that grain-boundaries are not the preferred location. An interesting correlation was found between the Q-drop onset, the quench field and the low-field energy gap, which supports the hypothesis of thermo-magnetic instability governing the Q-drop and the baking effect.

  14. MEASUREMENT OF THE HIGH-FIELD Q-DROP IN A LARGE-GRAIN NIOBIUM CAVITY FOR DIFFERENT OXIDATION PROCESSES

    SciTech Connect

    Gianluigi Ciovati; Peter Kneisel; Alex Gurevich

    2008-01-23

    In this contribution, we present the results from a series of RF tests at 1.7 K and 2.0 K on a single-cell cavity made of high-purity large (with area of the order of few cm2) grain niobium which underwent various oxidation processes. After initial buffered chemical polishing, anodization, baking in pure oxygen atmosphere and baking in air up to 180 °C was applied with the objective of clearly identifying the role of oxygen and the oxide layer on the Q-drop. During each rf test a temperature mapping system was used allowing to measure the local temperature rise of the cavity outer surface due to RF losses, which gives information about the losses location, their field dependence and space distribution on the RF surface. The results confirmed that the depth affected by baking is about 20 – 30 nm from the surface and showed that the Q-drop did not re-appear in a previously baked cavity by further baking at 120 °C in pure oxygen atmosphere or in air up to 180 °C. A statistic of the position of the "hot-spots" on the cavity surface showed that grain-boundaries are not the preferred location. An interesting correlation was found between the Q-drop onset, the quench field and the low-field energy gap, which supports the hypothesis of thermomagnetic instability governing the Q-drop and the baking effect.

  15. Examining gray matter structures associated with individual differences in global life satisfaction in a large sample of young adults.

    PubMed

    Kong, Feng; Ding, Ke; Yang, Zetian; Dang, Xiaobin; Hu, Siyuan; Song, Yiying; Liu, Jia

    2015-07-01

    Although much attention has been directed towards life satisfaction that refers to an individual's general cognitive evaluations of his or her life as a whole, little is known about the neural basis underlying global life satisfaction. In this study, we used voxel-based morphometry to investigate the structural neural correlates of life satisfaction in a large sample of young healthy adults (n = 299). We showed that individuals' life satisfaction was positively correlated with the regional gray matter volume (rGMV) in the right parahippocampal gyrus (PHG), and negatively correlated with the rGMV in the left precuneus and left ventromedial prefrontal cortex. This pattern of results remained significant even after controlling for the effect of general positive and negative affect, suggesting a unique structural correlates of life satisfaction. Furthermore, we found that self-esteem partially mediated the association between the PHG volume and life satisfaction as well as that between the precuneus volume and global life satisfaction. Taken together, we provide the first evidence for the structural neural basis of life satisfaction, and highlight that self-esteem might play a crucial role in cultivating an individual's life satisfaction. PMID:25406366

  16. Quiet Sun coronal heating: Analyzing large scale magnetic structures driven by different small-scale uniform sources

    NASA Astrophysics Data System (ADS)

    Podladchikova, O.; Dudok de Wit, T.; Krasnoselskikh, V.; Lefebvre, B.

    2002-02-01

    Recent measurements of quiet Sun heating events by Krucker & Benz (\\cite{Krucker98}) give strong support to Parker's (\\cite?) hypothesis that small-scale dissipative events make the main contribution to quiet heating. Moreover, combining their observations with the analysis by Priest et al. (\\cite{pr1}), it can be concluded that the sources driving these dissipative events are also small-scale sources, typically of the order of (or smaller than) 2000 km and below the resolution of modern instruments. Thus the question arises of how these small scale events participate in the larger-scale observable phenomena, and how the information about small scales can be extracted from observations. This problem is treated in the framework of a simple phenomenological model introduced in Krasnoselskikh et al. (\\cite{KPL}), which allows one to switch between various small-scale sources and dissipative processes. The large-scale structure of the magnetic field is studied by means of Singular Value Decomposition (SVD) and a derived entropy, techniques which are readily applicable to experimental data.

  17. Quiet Sun coronal heating: analyzing large scale magnetic structures driven by different small-scale uniform sources.

    NASA Astrophysics Data System (ADS)

    Podladchikova, O.; Krasnoselskikh, V.; Dudok de Wit, T.; Lefebvre, B.

    2001-12-01

    Recent measurements of quiet Sun heating events by Krucker & Benz [1] give strong support to Parker's [2] hypothesis that small scale dissipative events make the main contribution to the quiet heating. Moreover, combining their observations with the analysis by Priest et al. [3], it can be concluded that the sources driving these dissipative events are also small scale sources, typically of the order of (or smaller than) 2000 km and the resolution of modern instruments. Thus arises the question of how these small scale events participate into the larger scale observable phenomena, and how the information about small scales can be extracted from observations. This problem is treated in the framework of a simple phenomenological model introduced by Krasnoselskikh et al. [4], which allows to switch between various small scale sources and dissipative processes. The large scale structure of the magnetic field is studied by means of Singular Value Decomposition (SVD) and a derived entropy, techniques which are readily applicable to experimental data. \\begin{thebibliography}{99} \\bibitem{Krucker98} Krucker, S., & Benz, A.O. 1998, ApJ 501, L213 \\bibitem? Parker, E.N. 1988, ApJ. 330, 474 \\bibitem {pr1} Priest, E.R., Foley, C.R., Heyvaerts, J., et al. 2000, ApJ. 539, 1002 \\bibitem {KPL} Krasnoselskikh, V., Podladchikova, O., Lefebvre, B. & Vilmer, N. 2001

  18. Applications of different turbulence models in simulations of a large annular volute-type pump with the diffuser

    NASA Astrophysics Data System (ADS)

    Mao, J. Y.; Yuan, S. Q.; Pei, J.; Zhang, J. F.; Wang, W. J.

    2014-12-01

    It's necessary to choose a good turbulence model for the reliable numerical simulation of the pump in hydraulic optimization. In this paper, the four widely used turbulence models are selected and compared in three dimensional steady numerical simulations for a large annular volute-type pump with the diffuser. The pump performance is verified by the experiments in an open test rig. The results show that the SST turbulence model gets closer values to the experiment in predicting head. The trend of the pressure distribution at design condition for the four models on pressure side is very similar, which first increases and then decreases along the streamline. There are a minimum at 0.05 and a maximum at 0.8 of the length of the streamline, due to the existence of vortices. The predicted pressure distribution on the suction side is more similar. With the increase of flow rate, the flow field in the impeller becomes more uniform, and the number as well as the size of the vortices decrease. Secondary flow is observed in the volute and three vortices are found near the upside of the volute.

  19. Differences in recruitment and early retention among ethnic minority participants in a large pediatric cohort: The TEDDY Study

    PubMed Central

    Baxter, Judith; Vehik, Kendra; Johnson, Suzanne Bennett; Lernmark, Barbro; Roth, Roswith; Simell, Tuula

    2013-01-01

    Objective The TEDDY Study is an international, multi-center prospective study designed to identify the environmental triggers of type 1 diabetes (T1D) in genetically at-risk children. This report investigates ethnic minority (EM) differences in patterns of enrollment and retention in the US centers. Methods As of June 2009, 267,739 newborns had been screened at birth for high risk T1D genotypes. Data collected at the time of screening, enrollment and at the baseline visit were used. Descriptive and multiple-logistic regression analyses assessed differences between EM groups regarding exclusion, enrollment and early withdrawal. Results Of the 10,975 eligible subjects, 6,912 (67%) were invited to participate. EM subjects were more likely to be excluded because of an inability to contact. Of those invited 3,265 (47%) enrolled by the age of 4.5 months. Adjusted analyses showed that except for those classified as other EM, the odds of enrolling were similar across groups. EM subjects had elevated early withdrawal rates. Adjusted models demonstrated that this was significantly more likely among Hispanic subjects. Conclusion Understanding patterns associated with EM participation in research extends our ability to make more accurate inferences and permits assessment of strategies that promote inclusion of EM to better address health disparities. PMID:22484339

  20. Combined MIPAS (airborne/satellite), CALIPSO and in situ study on large potential NAT particles observed in early Arctic winter stratosphere in December 2011

    NASA Astrophysics Data System (ADS)

    Woiwode, Wolfgang; Höpfner, Michael; Pitts, Michael; Poole, Lamont; Oelhaf, Hermann; Molleker, Sergej; Borrmann, Stephan; Ebersoldt, Andreas; Frey, Wiebke; Gulde, Thomas; Maucher, Guido; Piesch, Christof; Sartorius, Christian; Orphal, Johannes

    2015-04-01

    The understanding of the characteristics of large HNO3-containing particles (potential 'NAT-rocks') involved in vertical redistribution of HNO3 in the polar winter stratosphere is limited due to the difficult accessibility of these particles by observations. While robust polar stratospheric cloud (PSC) classification schemes exist for observations by the space-borne lidar aboard CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) as well as for the passive mid-infrared limb observations by MIPAS (Michelson Interferometer for Passive Atmospheric Sounding), these observations are hardly exploited for the detection of large (diameter >10 ?m) NAT particles. This is due to the facts that these particles have low overall number densities, resulting in weak detectable signatures, and that the physical characteristics of these particles (i.e. shape, morphology, HNO3-content and optical characteristics) are uncertain. We investigate collocated and complementary observations of a low-density potential large NAT particle field by the space-borne instruments CALIPSO and MIPAS-ENVISAT as well as the airborne observations by the limb-sounder MIPAS-STR and the in situ particle probe FSSP-100 (Forward Scattering Spectrometer Probe 100) aboard the high-altitude aircraft Geophysica. The observations aboard the Geophysica on 11 December 2011 associated to ESSenCe (ESa Sounder Campaign 2011) provided us the unique opportunity to study in detail the lower boundary region of a PSC where large potential NAT particles (>20 ?m in diameter) were detected in situ. We analyse the ambient temperatures and gas-phase composition (HNO3 and H2O), the signatures of the observed particles in the CALIPSO and MIPAS observations, the HNO3-content of these particles suggested by the FSSP-100 and MIPAS-STR observations, and focus on the spectral fingerprint of these particles in the MIPAS-STR observations. While the spectral characterisation of the observed particles is subject of ongoing work, our results support that these particles consist of NAT and that the particle shape plays a crucial role.