These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Rheological Behaviour of Wheat Glutens at Small and Large Deformations. Comparison of Two Glutens Differing in Bread Making Potential  

Microsoft Academic Search

The rheological characteristics of hydrated cv. Obelisk and Katepwa glutens, with poor and good baking potential, respectively, were studied at small and large deformations. Dynamic (oscillatory) measurements at small deformations over a frequency range of 0·03 to 3 rad\\/s showed that cv. Katepwa gluten had a higher dynamic modulus and a lower loss tangent than cv. Obelisk gluten. Overmixing resulted

A. M. Janssen; T. van Vliet; J. M. Vereijken

1996-01-01

2

Homogenization with large spatial random potential  

E-print Network

We consider the homogenization of parabolic equations with large spatially-dependent potentials modeled as Gaussian random fields. We derive the homogenized equations in the limit of vanishing correlation length of the random potential. We characterize the leading effect in the random fluctuations and show that their spatial moments converge in law to Gaussian random variables. Both results hold for sufficiently small times and in sufficiently large spatial dimensions $d\\geq\\m$, where $\\m$ is the order of the spatial pseudo-differential operator in the parabolic equation. In dimension $d<\\m$, the solution to the parabolic equation is shown to converge to the (non-deterministic) solution of a stochastic equation in the companion paper [2]. The results are then extended to cover the case of long range random potentials, which generate larger, but still asymptotically Gaussian, random fluctuations.

Guillaume Bal

2008-09-05

3

Potential of large format camera photography  

NASA Astrophysics Data System (ADS)

The simulated system study explores the potential of large format camera (LFC) photography for conducting photogrammetric control extension. The study is based on a series of error propagation analyses in photogrammetric triangulation of a block of 22 LFC photographs. The photographs, which have an approx. scale of 1:755,000, were taken during the Oct. 1984 NASA shuttle mission STS-41G. Several present and future systems of data acquisition and reduction were simulated.

Malhotra, Roop C.

1988-08-01

4

Modeling emf, Potential Difference, and Internal Resistance  

NSDL National Science Digital Library

Through class discussion and think-pair-share questions, this activity helps students come to understand the difference between emf and potential difference in electrical circuits. These concepts are broached within the context of internal resistance of batteries.

Maier, Steven

5

On the Potential of Large Ring Lasers  

E-print Network

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.

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

2007-07-10

6

Accuracy potentials for large space antenna structures  

NASA Technical Reports Server (NTRS)

The relationships among materials selection, truss design, and manufacturing techniques in the interest of surface accuracies for large space antennas are discussed. Among the antenna configurations considered are: tetrahedral truss, pretensioned truss, and geodesic dome and radial rib structures. Comparisons are made of the accuracy achievable by truss and dome structure types for a wide variety of diameters, focal lengths, and wavelength of radiated signal, taking into account such deforming influences as solar heating-caused thermal transients and thermal gradients.

Hedgepeth, J. M.

1980-01-01

7

Thermodynamics of QCD at large quark chemical potential  

E-print Network

We review the existing weak-coupling results on the thermodynamic potential of deconfined QCD at small and large quark chemical potential and compare with results from lattice gauge theory as well as the exactly solvable case of large-N_f QCD. We also discuss the new analytical results on non-Fermi-liquid effects in entropy and specific heat as well as in dispersion laws of quark quasiparticles at large quark chemical potential.

Andreas Gerhold; Andreas Ipp; Anton Rebhan

2005-12-21

8

Inversion of potential fields on nodes for large grids  

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

9

Challenging High Potential Students in Large Classes: A Hurdles Approach  

ERIC Educational Resources Information Center

A hurdles approach, where qualitatively different expectations are linked to higher grades is suggested as a way of challenging high performing students in large classes with extreme range in ability. Large classes and increasing range in student ability and preparedness as well as diverse student learning styles have made it difficult to design…

Cleek, Margaret A.

2005-01-01

10

Large gauged Q-balls with regular potential  

NASA Astrophysics Data System (ADS)

In many models of gauged Q-balls, which were studied in the literature, there are upper limits for charge Q (and size) of Q-balls due to repulsive Coulomb force. The only known model that allows large Q without limitation is the V-shaped potential, V ?|? |, which is singular at ? =0 . To make it clear whether the property of unlimited Q is peculiar to the singular potential, we derive general conditions for potentials that allow Q-balls with unbounded Q . We find that large gauged Q -balls exist even for regular potentials. One of the simple models is V =(?2/2 )?2[1 +K ln (? /M )2] with K <0 . We investigate equilibrium solutions for this model systematically. As the electric charge Q increases, the field configuration of the scalar field becomes shell-like; because the charge is concentrated on the surface, the Coulomb force does not destroy the Q-ball configuration. These properties are analogous to those in the V-shaped model. We also find that for each K there is another sequence of unstable solutions, which is separated from the other sequence of the stable solutions. As |K | increases, the two sequences approach; eventually at some point in -1.07

Tamaki, Takashi; Sakai, Nobuyuki

2014-10-01

11

Identifying Granularity Differences between Large Biomedical Ontologies through Rules  

PubMed Central

The objective of this study is to identify the granularity differences as well as similarity between large biomedical ontologies through rules. Two anatomical ontologies were selected, and based on a set of concept mappings obtained through simple string matching techniques, we constructed rules to distinguish among different types of subclasses and classifications. 82% of the concept mappings have exactly the same classification in subclasses between the two ontologies. Other mappings are classified in different granularity, including additional subclasses, detailed classification, and different intermediate classification concepts. Using rules and the rule inference engine enables an automatic and scalable investigation of the structural incompatibility among biomedical ontologies. PMID:21347114

Sun, Pengfei; Zhang, Songmao

2010-01-01

12

A Methodology for Estimating Large-Customer Demand Response MarketPotential  

SciTech Connect

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.

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

2007-08-01

13

Very large common fragile site genes and their potential role in cancer development.  

PubMed

Common fragile sites (CFSs) are large chromosomal regions that are hot-spots for alterations especially within cancer cells. The three most frequently expressed CFS regions (FRA3B, FRA16D and FRA6E) contain genes that span extremely large genomic regions (FHIT, WWOX and PARK2, respectively), and these genes were found to function as important tumor suppressors. Many other CFS regions contain extremely large genes that are also targets of alterations in multiple cancers, but none have yet been demonstrated to function as tumor suppressors. The loss of expression of just FHIT or WWOX has been found to be associated with a worse overall clinical outcome. Studies in different cancers have revealed that some cancers have decreased expression of multiple large CFS genes. This loss of expression could have a profound phenotypic effect on these cells. In this review, we will summarize the known large common fragile site genes and discuss their potential relationship to cancer development. PMID:25300511

Gao, Ge; Smith, David I

2014-12-01

14

Small and large earthquakes: evidence for a different rupture beginning  

NASA Astrophysics Data System (ADS)

For the real-time magnitude estimate two Early Warning (EW) parameters are usually measured within 3 seconds of P-wave signal. These are the initial peak displacement (Pd) and the average period (?c). The scaling laws between EW parameters and magnitude are robust and effective up to magnitude 6.5-7 but a well known saturation problem for both parameters is evident for larger earthquakes. The saturation is likely due to the source finiteness so that only a few seconds of the P-wave cannot capture the entire rupture process of a large event. Here we propose an evolutionary approach for the magnitude estimate, based on the progressive expansion of the P-wave time window, until the expected arrival of the S-waves. The methodology has already been applied to the 2011, Mw 9.0 Tohoku-Oki earthquake records and showed that a minimum time window of 25-30 seconds is indeed needed to get stable magnitude estimate for a magnitude M ? 8.5 earthquake. Here we extend the analysis to a larger data set of Japanese earthquakes with magnitude between 4 and 9, using a high number of records per earthquake and spanning wide distance and azimuth ranges. We analyze the relationship between the time evolution of EW parameters and the earthquake magnitude itself with the purpose to understand the evolution of these parameters during the rupture process and to investigate a possible different scaling for both small and large events. We show that the initial increase of P-wave motion is more rapid for small earthquakes that for larger ones, thus implying a longer and wider nucleation phase for large events. Our results indicate that earthquakes breaking in a region with a large critical slip displacement value have a larger probability to grow into a large size rupture than those originating in a region with a smaller critical displacement value.

Colombelli, Simona; Zollo, Aldo; Festa, Gaetano; Picozzi, Matteo

2014-05-01

15

A micropump based on water potential difference in plants  

Microsoft Academic Search

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

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

16

Contribution potential of glaciers to water availability in different climate regimes  

E-print Network

Contribution potential of glaciers to water availability in different climate regimes Georg Kaser the contribution potential of seasonally delayed glacier melt water to total water availability in large river missing, considerable detrimen- tal changes due to shrinking glaciers are universally expected for water

Marzeion, Ben

17

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

PubMed Central

Background and Aims In neotropical forests, very small-seeded pioneer species (<0·1 mg seed mass) recruit preferentially in small tree fall gaps and at gap edges, but large-seeded pioneers do not. Since water availability is related to gap size, these differences in microsite preference may reflect in part species-specific differences in germination at reduced water potentials. Methods For 14 neotropical pioneer species, the hypothesis is tested that small-seeded species, with shallow initial rooting depths, reduce the risks associated with desiccation by germinating more slowly and at higher water potentials than large-seeded species. Key Results Germination occurred both more quickly and at lower water potentials with increasing seed mass. For example, Ochroma pyramidale (seed mass 5·5 mg) had a time to 50 % germination (T50) of 2·8 d and a median base potential for germination (?b50) of ?1·8 MPa while Clidemia quinquenervia (seed mass 0·017 mg) had a T50 of 17·6 d and ?b50 of ?1·1 MPa. Conclusions These data suggest that small-seeded species germinate only in comparatively moist microsites, such as small canopy gaps, which may reduce the risk of drought-induced mortality. Conversely, large-seeded species are able to germinate in the drier environment of large gaps, where they benefit by enhanced seedling growth in a high irradiance environment. The positive association of seed size and canopy gap size for optimal seedling establishment is maintained by differential germination responses to soil water availability coupled with the scaling of radicle growth rate and seed size, which collectively confer greater drought tolerance on large-seeded species. PMID:18840874

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

2008-01-01

18

A Large Potential Methane Source—Natural Gas Hydrates  

Microsoft Academic Search

Natural gas, essentially methane, can be obtained from natural gas hydrate (NGH). NGH reserves are difficult to pinpoint in the subsurface, but large sources have been identified by seismic reflection. This is particularly so below the sea floor near continental shelf plates in the oceans deeper than 300 m as NGH is stable at 4°C and 50 bar pressure. When

R. A. Dawe; S. Thomas

2007-01-01

19

Accuracy potentials for large space antenna reflectors with passive structure  

NASA Technical Reports Server (NTRS)

Analytical results indicate that a careful selection of materials and truss design, combined with accurate manufacturing techniques, can result in very accurate surfaces for large space antennas. The purpose of this paper is to examine these relationships for various types of structural configurations. Comparisons are made of the accuracy achievable by truss- and dome-type structures for a wide range of diameter and focal length of the antenna and wavelength of the radiated signal.

Hedgepeth, J. M.

1982-01-01

20

Potential role of large oceanic diatoms in new primary production  

NASA Astrophysics Data System (ADS)

Very large phytoplankton species >50 ?m in size, particularly diatoms, generally are found in background numbers throughout the euphotic zone of oceanic waters. Yet, when responding to episodic injections of new nutrients across the nutricline at the base of the euphotic zone these phototrophs may make a disproportionately large contribution to new primary production. To test this concept, we isolated a group of large diatoms from the Sargasso Sea and found that the specific growth rate of several of these species in culture was great enough at the ?2% light level in oligotrophic waters to meet the requirements of several hypothetical scenarios in which annual rates of new production from the sum of one or more episodic blooms were equal to contemporary estimates. Two of the fast-growing species, Stephanopyxis palmeriana (Greville) Grunow and Pseudoguinardia recta von Stosch, formed giant flocculant masses while growing. Such masses could sink rapidly out of the euphotic zone or be a direct food source for invertebrates or fish higher up the food chain. Not only would a short, simple trophic system with low losses result, but the events would virtually be impossible to observe with conventional sampling.

Goldman, Joel C.

1993-01-01

21

One Week Before the Election, Nader's Potential Impact Looms Large  

NSDL National Science Digital Library

Over the weekend, Democratic Vice-Presidential candidate Joe Lieberman urged Nader-supporters to consider that a vote for Nader could well end up giving George W. Bush the White House. Lieberman was echoing the thoughts of a growing number of liberals, including Gloria Steinem and the presidents of the Sierra Club and the National Organization for Women, who are stumping for Gore in selected toss-up states. Such concerns are justified by recent polling data that give Nader sufficient support in states like Washington, Oregon, Wisconsin, Minnesota, and Michigan to tip the balance from Gore to Bush, assuming, as most polls show, that Nader draws more from potential Gore voters than potential Bush voters. In this same vein, some earlier prominent, Nader-led activists, dubbed "Nader's Raiders," have shifted their loyalties and, at the prospect of a Bush presidency, turned to Gore. But the Green Party's candidate is himself undeterred, stating frankly on ABC News's This Week Sunday that "if he [Gore] cannot defeat the bumbling Texas governor with that horrific record, what good is he? It should be a slam dunk." Analysts are divided over whether would-be Nader voters will break at the last minute for Gore, accepting the thinking of democratic leaders that only a vote for a potential winner means anything, or whether they will stick with Nader, using their vote, it would seem, to express a fundamental dissatisfaction with the current political system.

Charbonneau, David D.

22

Liquefaction Potential of Unsaturated Nevada Sand at Different Initial Conditions  

NASA Astrophysics Data System (ADS)

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

Xu, Jiting

23

On hemispheric differences in evoked potentials to speech stimuli  

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

24

Solar Energy Utilisation Potential of three different Swiss Urban Sites  

Microsoft Academic Search

Besides providing a more efficient energy use, a large scale application of solar energy technologies in the urban context will be required in the upcoming decades to achieve a drastic reduction of greenhouse gas emissions in the biosphere. Three different urban sites, representative of three of the largest Swiss cities (Basel, Geneva and Lausanne), were examined in order to assess

M Montavon; J-L Scartezzini; R Compagnon

25

Betavoltaics using scandium tritide and contact potential difference  

Microsoft Academic Search

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

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

2008-01-01

26

Betavoltaics using scandium tritide and contact potential difference  

Microsoft Academic Search

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

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

2008-01-01

27

Comparison of different proximity potentials for asymmetric colliding nuclei  

SciTech Connect

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.

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

2010-06-15

28

Recent development of phosphorylases possessing large potential for oligosaccharide synthesis.  

PubMed

Phosphorylases are one group of carbohydrate active enzymes involved in the cleavage and formation of glycosidic linkages together with glycoside hydrolases and sugar nucleotide-dependent glycosyltransferases. Noticeably, the catalyzed phosphorolysis is reversible, making phosphorylases suitable catalysts for efficient synthesis of particular oligosaccharides from a donor sugar 1-phosphate and suitable carbohydrate acceptors with strict regioselectivity. Although utilization of phosphorylases for oligosaccharide synthesis has been limited because only few different enzymes are known, recently the number of reported phosphorylases has gradually increased, providing the variation making these enzymes useful tools for efficient synthesis of diverse oligosaccharides. PMID:23403067

Nakai, Hiroyuki; Kitaoka, Motomitsu; Svensson, Birte; Ohtsubo, Ken'ichi

2013-04-01

29

Multiple Large Bowel Resections: Potential Risk Factor For Anastomotic Leak  

PubMed Central

Objectives Identify risk factors of anastomotic leak (AL) after large bowel resection (LBR) for ovarian cancer (OC) and compare outcomes between AL and no AL. Methods All cases of AL after LBR for OC between 01/01/1994-05/20/2011 were identified and matched 1:2 with controls for age (+/?5years), sub-stage (IIIA/IIIB;IIIC;IV), and date of surgery (+/?4years). Patient-specific and intraoperative risk factors, use of protective stomas, and outcomes were abstracted. A stratified conditional logistic regression model was fit to determine the association between each factor and AL. Results 42 AL cases were evaluable and matched with 84 controls. Two-thirds of the AL had stage IIIC disease and >90% of both cases and controls were cytoreduced to <1cm residual disease. No patient-specific risk factors were associated with AL (pre-operative albumin was not available for most patients). Rectosigmoid resection coupled with additional LBR was associated with AL (OR=2.73, 95%CI 1.13–6.59, P=0.025), and protective stomas were associated with decreased risk of AL (0% vs. 10.7%, P=0.024). AL had longer length of stay (P<0.001), were less likely to start chemotherapy (P=0.020), and had longer time to chemotherapy (P=0.007). Cases tended to have higher 90-day mortality (P=0.061) and were more likely to have poorer overall survival (HR=2.05, 95%CI 1.18–3.57, P=0.011). Conclusions Multiple LBRs appear to be associated with increased risk of AL and protective stomas with decreased risk. Since AL after OC cytoreduction significantly delays chemotherapy and negatively impacts survival, surgeons should strongly consider temporary diversion in selected patients (poor nutritional status, multiple LBRs, previous pelvic radiation, very low anterior resection, steroid use). PMID:23578541

Kalogera, Eleftheria; Dowdy, Sean C.; Mariani, Andrea; Weaver, Amy L.; Aletti, Giovanni; Bakkum-Gamez, Jamie N.; Cliby, William A.

2013-01-01

30

Betavoltaics using scandium tritide and contact potential difference  

NASA Astrophysics Data System (ADS)

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.

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

2008-02-01

31

Large phase difference of soliton-like mutually-trapped beam pairs in strong nonlocal media  

NASA Astrophysics Data System (ADS)

We discuss the propagation of two orthogonally polarized beams in nonlocal planar waveguides by variational approach as well as a numerical method. The evolution equations for parameters and the critical powers for soliton-like mutually-trapped propagation of the two beams are obtained. Moreover, we analyze the influence of coupling coefficient, initial power, birefringence and the degree of nonlocal on mutually-trapped propagation. In addition, we find that the two beams will have large phase difference since phase shifts of the two beams are different under certain conditions. This theoretical result may have potential applications in the light-control-light technology.

Wang, Qing; Li, Jingzhen

2014-10-01

32

Large Scale Tag Recommendation Using Different Image Representations  

Microsoft Academic Search

Abstract. Nowadays, geographical coordinates (geo-tags), social anno- tations (tags), and low-level features are available in large image datasets. In our paper, we exploit these three kinds of image descriptions to sug- gest possible annotations for new images uploaded to a social tagging system. In order to compare the benefits each of these description types brings to a tag recommender system

Rabeeh Abbasi; Marcin Grzegorzek; Steffen Staab

2009-01-01

33

Evaluating the Potential for Large-Scale Biodiesel Deployments in a Global Context  

E-print Network

Evaluating the Potential for Large-Scale Biodiesel Deployments in a Global Context by Matthew Johnston. All rights reserved. #12;#12;Evaluating the Potential for Large-Scale Biodiesel Deployments on the subject of biodiesel, but I can only hope she takes comfort knowing now much I appreciate everything she

Wisconsin at Madison, University of

34

Scaling differences between large interplate and intraplate earthquakes  

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

35

Differences in projection patterns between large and small corticothalamic terminals.  

PubMed

We injected tracer into wide regions of visual cortex in the cat to produce retrograde and orthograde labeling in the thalamus, chiefly in the lateral geniculate nucleus and lateral posterior-pulvinar complex (LP-Pulvinar). We used the electron microscope to measure the sizes of orthogradely labeled terminals in thalamus and used these measurements to help determine whether the terminals were "RL" (large, presumed excitatory) or "RS" (small, presumed excitatory). We also distinguished reciprocal regions, which were zones of corticothalamic feedback defined by the presence of many retrogradely labeled cell bodies and orthogradely labeled terminals, from nonreciprocal regions, which were zones of feedforward corticothalamic projections defined by the presence of orthogradely labeled terminals alone. The lateral geniculate nucleus, a reciprocal region, had retrogradely labeled cell bodies as well as labeled RS terminals. Likewise, reciprocal regions in LP-Pulvinar were dominated by labeled RS terminals. In contrast, nonreciprocal regions were dominated by labeled RL terminals. Based on other evidence of corticothalamic projections that RL and RS terminals derive, respectively, from layer 5 and layer 6, we suggest the same relationship here, leading to the conclusion that the corticothalamic input from layer 6 is largely feedback, whereas that from layer 5 is largely feedforward. This finding lends credence to a recent hypothesis that layer 5 corticothalamic axons represent the afferent limb of a cortico-thalamo-cortical pathway that is critical for corticocortical communication. PMID:15221954

Van Horn, Susan C; Sherman, S Murray

2004-07-26

36

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

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

37

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

SciTech Connect

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

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

2007-06-01

38

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

PubMed

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

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

2009-01-01

39

The potential of large studies for building genetic risk prediction models  

Cancer.gov

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

40

Assessing the differences in sensitivities of runoff to changes in climatic conditions across a large basin  

NASA Astrophysics Data System (ADS)

SummaryLong term average runoff depends largely on climatic conditions and is expected to change as climate change progresses, but to what degree and in which locations is uncertain. An analytical framework for assessing the sensitivity of runoff to changes in average precipitation and potential evaporation has recently been developed. This framework is based on Budyko's curve. It makes no assumptions about future climatic conditions and is simple to implement. Here we apply it spatially to the Murray Darling Basin (MDB) in Australia, for average 1981-2006 conditions, to gauge the differences in runoff sensitivity across different yield zones. The framework contains a catchment-specific parameter which is difficult to predict, and estimates of its value are explored and assessed. Results emphasise the importance of the spatial variation in runoff sensitivity. Due to the MDB's aridity, basin-average runoff is very low (around 28 mm y -1) and runoff is generally insensitive to changes in average precipitation and potential evaporation. Specifically, basin-wide runoff is expected to increase by 1 mm y -1 for a 10 mm y -1 increase in basin-average precipitation, and to remain unchanged for the same increase in potential evaporation. However, approximately 66% of basin flow originates from 12% of the basin's land area and in these few high yield catchments runoff is most sensitive to changes in climatic conditions. In the highest yield zone, runoff is expected to increase by 7 mm y -1 given a 10 mm y -1 increase in precipitation, and to decrease by around 4 mm y -1 for the same increase in potential evaporation. When applied spatially, this runoff sensitivity framework has the potential to help water managers and policy makers to target planning activities that seek to mitigate potential effects of a changing climate on water resources.

Donohue, Randall J.; Roderick, Michael L.; McVicar, Tim R.

2011-09-01

41

Redox potential difference between Desulfovibrio vulgaris and Clostridium beijerinckii flavodoxins.  

PubMed

The redox potential of the flavin mononucleotide (FMN) hydroquinones for one-electron reduction in the Desulfovibrio vulgaris ( D. vulgaris) flavodoxin ( E sq/hq for FMNH (*)/FMNH (-)) was calculated using the crystal structure of the relevant hydroquinone form and compared to the results of the Clostridium beijerinckii ( C. beijerinckii) flavodoxin. In D. vulgaris and C. beijerinckii flavodoxins, the protein side chain causes significant downshifts of 170 and 240 mV in E sq/hq, respectively. In the C. beijerinckii flavodoxin, the E sq/hq downshift because of the protein side chain is essentially compensated by the counter influence of the protein backbone ( E sq/hq upshift of 260 mV). However, in the D. vulgaris flavodoxin, the corresponding protein backbone influence on E sq/hq is significantly small, i.e., less than half of that in the C. beijerinckii flavodoxin. In particular, there is a significant difference in the influence of the protein backbone of the so-called 60s loop region between the two flavodoxins. The E sq/hq difference can be best explained by the lower compensation of the side chain influence by the backbone influence in the D. vulgaris flavodoxin than in the C. beijerinckii flavodoxin. PMID:18355044

Ishikita, Hiroshi

2008-04-15

42

Evaluation of Curvularia intermedia ( Cochliobolus intermedius) as a potential microbial herbicide for large crabgrass ( Digitaria sanguinalis)  

Microsoft Academic Search

Curvularia intermedia, anamorph of the fungus Cochliobolus intermedius, was isolated from diseased crabgrass (Digitaria sp.) plants and evaluated in greenhouse studies for its potential as a microbial herbicide for control of large crabgrass (Digitaria sanguinalis). The objectives were to evaluate the host range of the fungus and to determine mortality and dry-weight reductions of large crabgrass as influenced by concentrations

A Michael Tilley; H Lynn Walker

2002-01-01

43

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

SciTech Connect

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.

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

1995-12-31

44

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

Microsoft Academic Search

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

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

1995-01-01

45

Quark number density at imaginary chemical potential and its extrapolation to large real chemical potential by the effective model  

E-print Network

We evaluate quark number densities at imaginary chemical potential by lattice QCD with clover-improved two-flavor Wilson fermion. The quark number densities are extrapolated to the small real chemical potential region by assuming some function forms. The extrapolated quark number densities are consistent with those calculated at real chemical potential with the Taylor expansion method for the reweighting factors. In order to study the large real chemical potential region, we use the two-phase model consisting of the quantum hadrodynamics model for the hadron phase and the entanglement-PNJL model for the quark phase. The quantum hadrodynamics model is constructed to reproduce nuclear saturation properties, while the entanglement-PNJL model reproduces well lattice QCD data for the order parameters such as the Polyakov loop, the thermodynamic quantities and the screening masses. Then, we calculate the mass-radius relation of neutron stars and explore the hadron-quark phase transition with the two-phase model.

Junichi Takahashi; Junpei Sugano; Masahiro Ishii; Hiroaki Kouno; Masanobu Yahiro

2014-10-30

46

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

SciTech Connect

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

Tomboulis, E. T. [Department of Physics and Astronomy, UCLA, Los Angeles, California 90095-1547 (United States)] [Department of Physics and Astronomy, UCLA, Los Angeles, California 90095-1547 (United States)

2013-12-15

47

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

NASA Astrophysics Data System (ADS)

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.

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

2007-08-01

48

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

PubMed

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

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

2014-11-01

49

Artificial Boundary Conditions Based on the Difference Potentials Method  

NASA Technical Reports Server (NTRS)

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.

Tsynkov, Semyon V.

1996-01-01

50

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

51

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

52

Heavy quark potential from gauge/gravity duality: A large D analysis  

NASA Astrophysics Data System (ADS)

The heavy quark potential is calculated in the framework of gauge/gravity duality using the large-D approximation, where D is the number of dimensions transverse to the flux tube connecting a quark and an antiquark in a flat D+2-dimensional spacetime. We find that in the large-D limit the leading correction to the ground-state energy, as given by an effective Nambu-Goto string, arises not from the heavy modes but from the behavior of the massless modes in the vicinity of the quark and the antiquark. We estimate this correction and find that it should be visible in the near-future lattice QCD calculations of the heavy quark potential.

Vyas, Vikram

2013-02-01

53

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

E-print Network

at the soil pit scale (SWHC') and both the stone content at the soil pit scale and rock outcrop at the plot predictions being recorded for soils developed on marl, clay, and hollow silicate rocks, and in flat areas1 Mapping soil water holding capacity over large areas to predict the potential production

Paris-Sud XI, Université de

54

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

EPA Science Inventory

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

55

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

Microsoft Academic Search

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

Rebecca L. Rowe; Gail Taylor

2009-01-01

56

NYU researchers identify new potential therapeutic target for diffuse large B-cell lymphoma:  

Cancer.gov

Researchers from the NYU Cancer Institute, an NCI-designated cancer center at NYU Langone Medical Center, have discovered a new potential therapeutic target for Diffuse Large B-Cell Lymphoma (DLBCL), the most aggressive and common type of lymphoma in adults. The new study, published in the November 23 issue of Nature, reveals the underlying molecular mechanism contributing to the development of lymphomagenesis.

57

innovati nNREL Confirms Large Potential for Grid Integration of Wind, Solar Power  

E-print Network

innovati nNREL Confirms Large Potential for Grid Integration of Wind, Solar Power To fully harvest the nation's bountiful wind and solar resources, it is critical to know how much electrical power from penetrations of wind power. NREL is a national laboratory of the U.S. Department of Energy, Office of Energy

58

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

Microsoft Academic Search

Abstract 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

Rebecca L. Rowe; Gail Taylor

2007-01-01

59

An Individual Tree Simulation Model for Estimating Expected Values of Potentially Available Large Woody Debris (LWD)  

Microsoft Academic Search

Abstract An individual tree based simulation model for estimating expected values of poten- tially available large woody debris (LWD) was developed. Potentially available LWD was defined as LWD that could be recruited into a stream, from the standing live trees in an adjacent forest, if the trees were to fall. Expected values were based on stream intersection probabilities for the

Kevin R. Gehringer

60

The radiative forcing potential of different climate geoengineering options  

Microsoft Academic Search

Climate geoengineering proposals seek to rectify the Earth's current and potential future radiative imbalance, either by reducing the absorption of incoming solar (short- wave) radiation, or by removing CO2 from the atmosphere and transferring it to long-lived reservoirs, thus increasing outgoing longwave radiation. A fundamental criterion for evaluating geoengineering options is their climate cooling effectiveness, which we quantify here in

T. M. Lenton; N. E. Vaughan

2009-01-01

61

The radiative forcing potential of different climate geoengineering options  

Microsoft Academic Search

Climate geoengineering proposals seek to rectify the Earth's current and potential future radiative imbalance, either by reducing the absorption of incoming solar (shortwave) radiation, or by removing CO2 from the atmosphere and transferring it to long-lived reservoirs, thus increasing outgoing longwave radiation. A fundamental criterion for evaluating geoengineering options is their climate cooling effectiveness, which we quantify here in terms

T. M. Lenton; N. E. Vaughan

2009-01-01

62

Comparison among different high porosity stent configurations: hemodynamic effects of treatment in a large cerebral aneurysm.  

PubMed

Whether treated surgically or with endovascular techniques, large and giant cerebral aneurysms are particularly difficult to treat. Nevertheless, high porosity stents can be used to accomplish stent-assisted coiling and even standalone stent-based treatments that have been shown to improve the occlusion of such aneurysms. Further, stent assisted coiling can reduce the incidence of complications that sometimes result from embolic coiling (e.g., neck remnants and thromboembolism). However, in treating cerebral aneurysms at bifurcation termini, it remains unclear which configuration of high porosity stents will result in the most advantageous hemodynamic environment. The goal of this study was to compare how three different stent configurations affected fluid dynamics in a large patient-specific aneurysm model. Three common stent configurations were deployed into the model: a half-Y, a full-Y, and a crossbar configuration. Particle image velocimetry was used to examine post-treatment flow patterns and quantify root-mean-squared velocity magnitude (VRMS) within the aneurysmal sac. While each configuration did reduce VRMS within the aneurysm, the full-Y configuration resulted in the greatest reduction across all flow conditions (an average of 56% with respect to the untreated case). The experimental results agreed well with clinical follow up after treatment with the full-Y configuration; there was evidence of thrombosis within the sac from the stents alone before coil embolization was performed. A computational simulation of the full-Y configuration aligned well with the experimental and in vivo findings, indicating potential for clinically useful prediction of post-treatment hemodynamics. This study found that applying different stent configurations resulted in considerably different fluid dynamics in an anatomically accurate aneurysm model and that the full-Y configuration performed best. The study indicates that knowledge of how stent configurations will affect post-treatment hemodynamics could be important in interventional planning and demonstrates the capability for such planning based on novel computational tools. PMID:24337100

Roszelle, Breigh N; Nair, Priya; Gonzalez, L Fernando; Haithem Babiker, M; Ryan, Justin; Frakes, David

2014-02-01

63

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

SciTech Connect

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

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

2005-09-19

64

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

NASA Astrophysics Data System (ADS)

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

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

2006-03-01

65

Whitefly control potential of Eretmocerus parasitoids with different reproductive modes  

Microsoft Academic Search

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

M. J. Ardeh

2005-01-01

66

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

PubMed

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

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

2013-03-01

67

Measurement of electrostatic potential fluctuation using heavy ion beam probe in large helical device.  

PubMed

Heavy ion beam probe (HIBP) for large helical device (LHD) has been improved to measure the potential fluctuation in high-temperature plasmas. The spatial resolution is improved to about 10 mm by controlling the focus of a probe beam. The HIBP is applied to measure the potential fluctuation in plasmas where the rotational transform is controlled by electron cyclotron current drive. The fluctuations whose frequencies change with the time constant of a few hundreds of milliseconds and that with a constant frequency are observed. The characteristics of the latter fluctuation are similar to those of the geodesic acoustic mode oscillation. The spatial profiles of the fluctuations are also obtained. PMID:19044631

Ido, Takeshi; Shimizu, Akihiro; Nishiura, Masaki; Nakano, Haruhisa; Ohshima, Shinsuke; Kato, Shinji; Hamada, Yasuji; Yoshimura, Yasuo; Kubo, Shin; Shimozuma, Takashi; Igami, Hiroe; Takahashi, Hiromi; Toi, Kazuo; Watanabe, Fumitake

2008-10-01

68

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

Microsoft Academic Search

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

Surendra Suthar

2007-01-01

69

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

SciTech Connect

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

Panwar, Anuraj; Rizvi, H.; Ryu, C. M. [Department of Physics, POSTECH, Hyoja-Dong San 31, Pohang, KyungBuk 790-784 (Korea, Republic of)] [Department of Physics, POSTECH, Hyoja-Dong San 31, Pohang, KyungBuk 790-784 (Korea, Republic of)

2013-11-15

70

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

NASA Astrophysics Data System (ADS)

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

Kobayashi, Naritaka; Asakawa, Hitoshi; Fukuma, Takeshi

2011-08-01

71

Potential impact of wind farms on territories of large eagles in southeastern Spain  

Microsoft Academic Search

Although wind farms in Spain have increased in numbers in recent years, their impact on birds, particularly large raptors,\\u000a has received relatively little attention in the scientific literature. We study the potential impact of 72 wind energy developments\\u000a planned for the south-east of Spain covering 128 golden eagle and 152 Bonelli’s eagle territories using nearest neighbour\\u000a distances (NND) as an

J. E. MartinezJ; J. F. Calvo; J. A. Martínez; I. Zuberogoitia; E. Cerezo; J. Manrique; G. J. Gómez; J. C. Nevado; M. Sánchez; R. Sánchez; J. Bayo; A. Pallarés; C. González; J. M. Gómez; P. Pérez; J. Motos

2010-01-01

72

Phytoremediation potential of Solanum nigrum L. under different cultivation protocols.  

PubMed

In this study, Solanum nigrum L. was used as a hyperaccumulator for remediation of cadmium contaminated soil, and 3 different cultivation protocols were investigated. The results showed that a double cropping treatment enhanced the phytoremediation efficiency significantly, since it increased the amount of Cd extracted in one growing season by a factor of 1.62 compared to single cropping. However, the labor cost for double cropping was twice that of single cropping. If the time consumed is considered as a cost of phytoremediation, the double cropping treatment might be considered as an effective and economic cultivation protocol by reducing the overall time required to reach the targeted soil quality. PMID:23778778

Qu, Guangzhou; Tong, Yan'an; Gao, Pengcheng; Zhao, Zuoping; Song, Xueying; Ji, Puhui

2013-09-01

73

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

NASA Astrophysics Data System (ADS)

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

Wagner, Dieter

74

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

SciTech Connect

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.

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

2010-04-15

75

Attitudes Toward Mountain Lion Management in the Midwest: Implications for a Potentially Recolonizing Large Predator  

Microsoft Academic Search

Mountain lion (Puma concolor) confirmations in the Midwest have increased considerably, indicating a potential recolonization event. Although the ecological, social, and economic implications of recolonization are of considerable interest to managers and the general public, no studies have yet assessed human attitudes toward mountain lion management in the region. We surveyed Kentucky and North Dakota residents and found differences in

Mae A. Davenport; Clayton K. Nielsen; Jean C. Mangun

2010-01-01

76

Effective Potential Approach to the Simulation of Large Para-Hydrogen Clusters and Droplets  

NASA Astrophysics Data System (ADS)

The quantum simulation of large molecular system is a formidable task. We explore the use of effective potentials based on the Feynman path centroid variable in order to simulate large quantum clusters at a reduced computational cost. This centroid can be viewed as the ``most classical'' variable of a quantum system. Earlier work has shown that one can use a pairwise centroid pseudo-potential to simulate the quantum dynamics of hydrogen in the bulk phase at 25 K and 14 K. Bulk hydrogen, however, freezes below 14 K and we rather focus on nanodroplets in the very low temperature regime in order to study the superfluid behaviour of hydrogen. The calculation of the effective potential will be discussed along with its use in the context of molecular dynamics simulations. Centroid structural properties will be presented and compared to the results of path integral Monte Carlo simulations. We will present an approach for de-convoluting centroid structural properties in order to obtain real space results for hydrogen clusters of a wide range of sizes. The extension of the approach to the treatment of confined hydrogen will be discussed. M. Pavese and G.A. Voth, Chem. Phys. Lett. 249, 231 (1996).

Yang, Jing; Roy, Pierre-Nicholas

2011-06-01

77

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

E-print Network

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

Evans, Jason

78

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

E-print Network

Rooting of stem cuttings of Populus x euramericana under different water potentials S. Puri1 F tissues. However, little is known about maintenance and control of plant water potential during plant water potential. Materials and Methods Variation in the initial plant water potential (4!P

Paris-Sud XI, Université de

79

Molecular dynamics simulations of stretched gold nanowires: The relative utility of different semiempirical potentials  

Microsoft Academic Search

The mechanical elongation of a finite gold nanowire has been studied by molecular dynamics simulations using different semiempirical potentials for transition metals. These potentials have been widely used to study the mechanical properties of finite metal clusters. Combining with density functional theory calculations along several atomic-configuration trajectories predicted by different semiempirical potentials, the authors conclude that the second-moment approximation of

Qing Pu; Yongsheng Leng; Leonidas Tsetseris; Harold S. Park; Sokrates T. Pantelides; Peter T. Cummings

2007-01-01

80

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

SciTech Connect

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

Morris, T.H.; Hebertson, G.F. [Brigham Young Univ., Provo, Utah (United States)

1996-07-01

81

Submm/FIR astronomy in Antarctica: Potential for a large telescope facility  

E-print Network

Preliminary site testing datasets suggest that Dome C in Antarctica is one of the best sites on Earth for astronomical observations in the 200 to 500 micron regime, i.e. for far-infrared (FIR) and submillimetre (submm) astronomy. We present an overview of potential science cases that could be addressed with a large telescope facility at Dome C. This paper also includes a presentation of the current knowledge about the site characterics in terms of atmospheric transmission, stability, sky noise and polar constraints on telescopes. Current and future site testing campaigns are finally described.

Vincent Minier; V. Minier; L. Olmi; P. -O. Lagage; L. Spinoglio; G. A. Durand; E. Daddi; D. Galilei; H. Gallee; C. Kramer; D. Marrone; E. Pantin; L. Sabbatini; N. Schneider; N. Tothill; L. Valenziano; C. Veyssiere

2008-05-16

82

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

PubMed

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

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

2014-07-23

83

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

PubMed

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

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

1997-02-01

84

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

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

85

Gender Differences in Academic Performance in a Large Public University in Turkey  

ERIC Educational Resources Information Center

The paper attempts to determine whether there are significant gender differences in academic performance among undergraduate students in a large public university in Turkey based on three indicators; university entrance scores, performance in the English preparatory school and in the program the student is majoring in. The paper finds that a…

Dayioglu, Meltem; Turut-Asik, Serap

2007-01-01

86

COMPARISON OF DIFFERENT ATTITUDE CONTROL SCHEMES 87-2391 FOR LARGE COMMUNICATIONS SATELLITES  

E-print Network

satellite. The work involved a linear time invariant analysis through modern control approachCOMPARISON OF DIFFERENT ATTITUDE CONTROL SCHEMES 87-2391 FOR LARGE COMMUNICATIONS SATELLITES S loop transfer function H(s) -backward loop transfer function Hzt -total momentum along yaw axis K,, 7

87

A spectral/finite difference method for simulating large deformations of heterogeneous, viscoelastic materials  

E-print Network

A spectral/finite difference method for simulating large deformations of heterogeneous deformations of heterogeneous, viscoelastic materials in two dimensions. The algorithm is based on a spectral/finite of an elastic and viscous element connected in series. The algorithm is especially suitable to simulate periodic

Podladchikov, Yuri

88

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

PubMed

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

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

2011-09-19

89

Precipitating electron fluxes formed by a magnetic field aligned potential difference  

Microsoft Academic Search

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

David S. Evans

1974-01-01

90

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

SciTech Connect

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.

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

1981-12-01

91

Potential for a large earthquake rupture of the San Ramón fault in Santiago, Chile  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

92

Potential and attainable food production and food security in different regions  

PubMed Central

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.

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

1997-01-01

93

Potential consequences of climate change for primary production and fish production in large marine ecosystems  

PubMed Central

Existing methods to predict the effects of climate change on the biomass and production of marine communities are predicated on modelling the interactions and dynamics of individual species, a very challenging approach when interactions and distributions are changing and little is known about the ecological mechanisms driving the responses of many species. An informative parallel approach is to develop size-based methods. These capture the properties of food webs that describe energy flux and production at a particular size, independent of species' ecology. We couple a physical–biogeochemical model with a dynamic, size-based food web model to predict the future effects of climate change on fish biomass and production in 11 large regional shelf seas, with and without fishing effects. Changes in potential fish production are shown to most strongly mirror changes in phytoplankton production. We project declines of 30–60% in potential fish production across some important areas of tropical shelf and upwelling seas, most notably in the eastern Indo-Pacific, the northern Humboldt and the North Canary Current. Conversely, in some areas of the high latitude shelf seas, the production of pelagic predators was projected to increase by 28–89%. PMID:23007086

Blanchard, Julia L.; Jennings, Simon; Holmes, Robert; Harle, James; Merino, Gorka; Allen, J. Icarus; Holt, Jason; Dulvy, Nicholas K.; Barange, Manuel

2012-01-01

94

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

SciTech Connect

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

Mia, Mohammed; Dasgupta, Keshav; Gale, Charles; Jeon, Sangyong [Ernest Rutherford Physics Building, McGill University, 3600 University Street, Montreal Quebec, H3A 2T8 (Canada)

2010-07-15

95

On the Definition of Surface Potentials for Finite-Difference Operators  

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

96

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

PubMed Central

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 (Ca2+) increase, etc.), on CBD behavioural effects. PMID:23108553

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

2012-01-01

97

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

PubMed

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

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

2012-12-01

98

Large-scale computational and statistical analyses of high transcription potentialities in 32 prokaryotic genomes  

PubMed Central

This article compares 32 bacterial genomes with respect to their high transcription potentialities. The ?70 promoter has been widely studied for Escherichia coli model and a consensus is known. Since transcriptional regulations are known to compensate for promoter weakness (i.e. when the promoter similarity with regard to the consensus is rather low), predicting functional promoters is a hard task. Instead, the research work presented here comes within the scope of investigating potentially high ORF expression, in relation with three criteria: (i) high similarity to the ?70 consensus (namely, the consensus variant appropriate for each genome), (ii) transcription strength reinforcement through a supplementary binding site—the upstream promoter (UP) element—and (iii) enhancement through an optimal Shine-Dalgarno (SD) sequence. We show that in the AT-rich Firmicutes’ genomes, frequencies of potentially strong ?70-like promoters are exceptionally high. Besides, though they contain a low number of strong promoters (SPs), some genomes may show a high proportion of promoters harbouring an UP element. Putative SPs of lesser quality are more frequently associated with an UP element than putative strong promoters of better quality. A meaningful difference is statistically ascertained when comparing bacterial genomes with similarly AT-rich genomes generated at random; the difference is the highest for Firmicutes. Comparing some Firmicutes genomes with similarly AT-rich Proteobacteria genomes, we confirm the Firmicutes specificity. We show that this specificity is neither explained by AT-bias nor genome size bias; neither does it originate in the abundance of optimal SD sequences, a typical and significant feature of Firmicutes more thoroughly analysed in our study. PMID:18440978

Sinoquet, Christine; Demey, Sylvain; Braun, Frederique

2008-01-01

99

Large-scale computational and statistical analyses of high transcription potentialities in 32 prokaryotic genomes.  

PubMed

This article compares 32 bacterial genomes with respect to their high transcription potentialities. The sigma70 promoter has been widely studied for Escherichia coli model and a consensus is known. Since transcriptional regulations are known to compensate for promoter weakness (i.e. when the promoter similarity with regard to the consensus is rather low), predicting functional promoters is a hard task. Instead, the research work presented here comes within the scope of investigating potentially high ORF expression, in relation with three criteria: (i) high similarity to the sigma70 consensus (namely, the consensus variant appropriate for each genome), (ii) transcription strength reinforcement through a supplementary binding site--the upstream promoter (UP) element--and (iii) enhancement through an optimal Shine-Dalgarno (SD) sequence. We show that in the AT-rich Firmicutes' genomes, frequencies of potentially strong sigma70-like promoters are exceptionally high. Besides, though they contain a low number of strong promoters (SPs), some genomes may show a high proportion of promoters harbouring an UP element. Putative SPs of lesser quality are more frequently associated with an UP element than putative strong promoters of better quality. A meaningful difference is statistically ascertained when comparing bacterial genomes with similarly AT-rich genomes generated at random; the difference is the highest for Firmicutes. Comparing some Firmicutes genomes with similarly AT-rich Proteobacteria genomes, we confirm the Firmicutes specificity. We show that this specificity is neither explained by AT-bias nor genome size bias; neither does it originate in the abundance of optimal SD sequences, a typical and significant feature of Firmicutes more thoroughly analysed in our study. PMID:18440978

Sinoquet, Christine; Demey, Sylvain; Braun, Frédérique

2008-06-01

100

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

E-print Network

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 ...

Im, Eun-Soon

101

Large Extracellular Loop of Tetraspanin as a Potential Vaccine Candidate for Filariasis  

PubMed Central

Lymphatic filariasis affects nearly 120 million people worldwide and mass preventive chemotherapy is currently used as a strategy to control this infection. This has substantially reduced the incidence of the infection in several parts of the world. However, a prophylactic vaccine would be more effective in preventing future infections and will supplement the mass chemotherapy efforts. Unfortunately, there is no licensed vaccine available currently to prevent this infection. Molecules expressed on the surface of the parasite are potential candidates for vaccine development as they are exposed to the host immune system. In this study we show that the large extracellular loop of tetraspanin (TSP LEL), a protein expressed on the cuticle of Brugia malayi and Wuchereria bancrofti is a potential vaccine candidate. Our results showed that BmTSP LEL is expressed on the surface of B. malayi infective third stage larvae (L3) and sera from human subjects who are putatively immune to lymphatic filariasis carry high titer of IgG1 and IgG3 antibodies against BmTSP LEL and WbTSP LEL. We also showed that these antibodies in the sera of human subjects can participate in the killing of B. malayi L3 in an antibody dependent cell-mediated cytotoxicity mechanism. Vaccination trials in mice showed that close to 64% protection were achieved against challenge infections with B. malayi L3. Immunized animals showed high titer of anti-WbTSP LEL IgG1, IgG2a and IgG2b antibodies in the sera and IFN-? secreting cells in the spleen. Onchocerca volvulus another filarial parasite also expresses TSP LEL. Cross-reactivity studies showed that IgG1 antibody in the sera of endemic normal subjects, recognize OvTSP LEL. Similarly, anti-OvTSP LEL antibodies in the sera of subjects who are immune to O. volvulus were also shown to cross-react with rWbTSP LEL and rBmTSP LEL. These findings thus suggested that rTSP LEL can be developed as a potential vaccine candidate against multiple filarial infections. PMID:24146990

Dakshinamoorthy, Gajalakshmi; Munirathinam, Gnanasekar; Stoicescu, Kristen; Reddy, Maryada Venkatarami; Kalyanasundaram, Ramaswamy

2013-01-01

102

Which water potential? Differences between isopiestic thermocouple psychrometer measurements of intact and excised plant materials  

Microsoft Academic Search

Water potentials of leaves from well-watered plants were measured. There were species-specific differences in both the total\\u000a and the osmotic potentials of pea (Pisum sativum), tradescantia (Tradescantia versicolor), rose (Rosa hybrida), bitter lemon (Citrus aurantium) and olive (Olea europaea). With tradescantia the potential measured after the destruction of turgor by freezing was less negative than before, a result\\u000a which suggests

Man Singh Manohar

1971-01-01

103

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

104

Gender Differences in Sexual Attitudes and Behaviors: A Review of Meta-Analytic Results and Large Datasets  

Microsoft Academic Search

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,

Jennifer L. Petersen; Janet Shibley Hyde

2011-01-01

105

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

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

106

Characterization of Nasal Potential Difference in cftr Knockout and F508del-CFTR Mice  

PubMed Central

Background Treatments designed to correct cystic fibrosis transmembrane conductance regulator (CFTR) defects must first be evaluated in preclinical experiments in the mouse model of cystic fibrosis (CF). Mice nasal mucosa mimics the bioelectric defect seen in humans. The use of nasal potential difference (VTE) to assess ionic transport is a powerful test evaluating the restoration of CFTR function. Nasal VTE in CF mice must be well characterized for correct interpretation. Methods We performed VTE measurements in large-scale studies of two mouse models of CF—B6;129 cftr knockout and FVB F508del-CFTR—and their respective wild-type (WT) littermates. We assessed the repeatability of the test for cftr knockout mice and defined cutoff points distinguishing between WT and F508del-CFTR mice. Results We determined the typical VTE values for CF and WT mice and demonstrated the existence of residual CFTR activity in F508del-CFTR mice. We characterized intra-animal variability in B6;129 mice and defined the cutoff points for F508del-CFTR chloride secretion rescue. Hyperpolarization of more than -2.15 mV after perfusion with a low-concentration Cl- solution was considered to indicate a normal response. Conclusions These data will make it possible to interpret changes in nasal VTE in mouse models of CF, in future preclinical studies. PMID:23505426

Saussereau, Emilie Lyne; Roussel, Delphine; Diallo, Siradiou; Debarbieux, Laurent; Edelman, Aleksander; Sermet-Gaudelus, Isabelle

2013-01-01

107

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

ERIC Educational Resources Information Center

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…

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

2013-01-01

108

Age-Dependent Telomere Attrition as a Potential Indicator of Racial Differences in Renal Growth Patterns  

Microsoft Academic Search

Background: Racial differences in the predilection to salt sensitivity may arise from different renal growth patterns. To test this idea, we monitored age-dependent telomere attrition rate, reflecting largely the replicative history of somatic cells, in the outer renal cortex and the inner renal medulla of African Americans and Caucasians. Methods: Telomere length, determined by the mean length of the terminal

L. Tchakmakjian; J. P. Gardner; P. D. Wilson; M. Kimura; J. Skurnick; H. R. Zielke; A. Aviv

2004-01-01

109

Gender differences in memory processing: Evidence from event-related potentials to faces  

Microsoft Academic Search

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

François Guillem; Melodee Mograss

2005-01-01

110

How Teachers and Schools Contribute to Racial Differences in the Realization of Academic Potential  

ERIC Educational Resources Information Center

Background/Context: The fulfillment of academic potential is an underdeveloped area of inquiry as it relates to explaining racial differences in academic outcomes. Examining this issue is important for addressing not only differences in the typical outcomes for African American and White students but also the severe underrepresentation of African…

Wildhagen, Tina

2012-01-01

111

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

ERIC Educational Resources Information Center

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

Guillem, F.; Mograss, M.

2005-01-01

112

Generation and homodyne detection of continuous-variable entangled optical beams with a large wavelength difference  

SciTech Connect

We present a scheme for generating and homodyne detecting of continuous-variable entanglement of bright optical beams with a large wavelength difference by utilizing an optical parametric oscillator (OPO) and an optical parametric amplifier (OPA) simultaneously. Entangled optical beams at 0.8 and 1.5 {mu}m are generated from the OPA; the seed beams injected in the OPA as well as the local oscillators at the two wavelengths needed for homodyne detection are provided by the OPO. The entangler is a ring resonator involving a second-order nonlinear crystal that is pumped from two opposite directions. In one direction the pump power is above the oscillation threshold and the optical nonlinear resonator operates as an OPO. In the other direction the pump power is below the threshold and it operates as a phase-sensitive frequency nondegenerate optical parametric amplifier. Our scheme combines the advantages of both OPO and OPA quantum optical devices and opens another avenue for preparation and homodyne detection of high quality bright entangled light with a large wavelength difference.

Guo Xiaomin; Xie Changde; Li Yongmin [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006 (China)

2011-08-15

113

Didactic Problems in the Concept of Electric Potential Difference and an Analysis of its Philogenesis  

NASA Astrophysics Data System (ADS)

This paper makes an analysis of the different didactic problems to come from the fact that electric charge is inseparable from the mass, the impossibility of its direct observation (only its effects) and the meaning associated with the basic concepts of electricity, like electric potential or electric potential difference.In order to know the origin of the different meaning found in textbooks of the concept of electric potential difference, we have made an analysis of the relevant historical milestones. In this review, it is seen that the content assigned to it is taken from the mathematical formalism of field theory, which causes problems in its structure and its logico-formal communication as well as teaching problems.

Jímenez Gomez, Enrique; Férnandez Duran, Eugenio

114

Effect of luminal ions on the transepithelial electrical potential difference of human rectum  

PubMed Central

Skin electrodes are the most convenient reference electrodes for clinical measurements of electrical potential differences (pd) across the epithelium of the alimentary tract but the presence of an electrical charge on normal skin introduces an error. In the present study, by comparison with results obtained using subcutaneous and intravenous electrodes, it was shown that an intradermal injection of saline abolished the skin potential differences. This simple method, therefore, allows skin electrodes to be used to measure the true transepithelial potential differences of gut mucosa. The method was applied to investigate the effect on the rectal potential difference of altering the composition of the luminal solutions. Changes in the cations (sodium, potassium, magnesium) showed that sodium was the most important cationic determinant of the potential difference, especially when sodium absorption was stimulated by giving mineralocorticoids. Changes in the anions (chloride, iodide, bromide, nitrate, bicarbonate, sulphate, phosphate, citrate, and acetate) indicated that the molecular size of the anion rather than its chemical nature was the significant factor and suggested that the ions had to cross a barrier relatively impermeable to anions of radius greater than 3·5 to 4 A°. Changes in osmolality and glucose concentration were without effect. PMID:5069733

Archampong, E. Q.; Edmonds, C. J.

1972-01-01

115

Evoked potentials in large-scale cortical networks elicited by TMS of the visual cortex  

PubMed Central

Single pulses of transcranial magnetic stimulation (TMS) result in distal and long-lasting oscillations, a finding directly challenging the virtual lesion hypothesis. Previous research supporting this finding has primarily come from stimulation of the motor cortex. We have used single-pulse TMS with simultaneous EEG to target seven brain regions, six of which belong to the visual system [left and right primary visual area V1, motion-sensitive human middle temporal cortex, and a ventral temporal region], as determined with functional MRI-guided neuronavigation, and a vertex “control” site to measure the network effects of the TMS pulse. We found the TMS-evoked potential (TMS-EP) over visual cortex consists mostly of site-dependent theta- and alphaband oscillations. These site-dependent oscillations extended beyond the stimulation site to functionally connected cortical regions and correspond to time windows where the EEG responses maximally diverge (40, 200, and 385 ms). Correlations revealed two site-independent oscillations ?350 ms after the TMS pulse: a theta-band oscillation carried by the frontal cortex, and an alpha-band oscillation over parietal and frontal cortical regions. A manipulation of stimulation intensity at one stimulation site (right hemisphere V1-V3) revealed sensitivity to the stimulation intensity at different regions of cortex, evidence of intensity tuning in regions distal to the site of stimulation. Together these results suggest that a TMS pulse applied to the visual cortex has a complex effect on brain function, engaging multiple brain networks functionally connected to the visual system with both invariant and site-specific spatiotemporal dynamics. With this characterization of TMS, we propose an alternative to the virtual lesion hypothesis. Rather than a technique that simulates lesions, we propose TMS generates natural brain signals and engages functional networks. PMID:21715670

Grossman, Emily D.; Srinivasan, Ramesh

2011-01-01

116

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

SciTech Connect

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.

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

117

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

NSDL National Science Digital Library

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.

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

2000-01-01

118

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

Microsoft Academic Search

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

Göksel N. Demirer; Metin Duran; Engin Güven; Örgen Ugurlu; Ulas Tezel; Tuba H. Ergüder

2000-01-01

119

Evaluation of different calibration strategies for large scale continuous hydrological modelling  

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

120

Comparative histologic study of adenomas of the large intestine in Japan and England, with special reference to malignant potential  

Microsoft Academic Search

Summary  The malignant potential of large-intestinal adenomas varies with size, histologic type, and grade of epithelial atypia in\\u000a the same way in England and in Japan. Adenomas in England have greater malignant potential than those in Japan because they\\u000a grow larger and more often show a villous growth pattern. Although the adenomacarcinoma sequence operates in the same way\\u000a in the two

T. Muto; K. Ishikawa; I. Kino; K. Nakamura; H. Sugano; H. J. R. Bussey; B. C. Morson

1977-01-01

121

Placental mesenchymal stem cells of fetal and maternal origins demonstrate different therapeutic potentials  

PubMed Central

Introduction Therapeutic potentials of mesenchymal stem cells (MSCs) from different sources have been evaluated in pre-clinical and clinical settings. Although MSCs from different sources share MSC-specific characteristics and functions, inconsistent or controversial results of pre-clinical and clinical applications of such cells are frequently reported. This may be partially due to the fact that MSCs isolated from different origins may differentially express some functions not typical for MSCs, and hence have different therapeutic potentials. The aim of this study is to investigate the differences in human placental MSCs (P-MSCs) of fetal and maternal origins in the aspects of clinical importance. Methods P-MSCs of fetal and maternal origins isolated from normal term placentas were characterized for their typical phenotype as well as their expression of receptors and growth factors of clinic interests. P-MSCs that preferentially express hepatocyte growth factor (HGF) and CD200 were evaluated for their therapeutic potentials in models of angiogenesis and allogeneic skin transplantation, in comparison with their HGF and CD200 negative partners. Results Although all P-MSCs express typical MSC phenotype, fetal but not maternal P-MSCs express high levels of CD200 and HGF. Compared with HGF and CD200 negative P-MSCs, HGF and CD200 positive cells demonstrated significantly high potentials in promoting angiogenesis in vitro and increasing immunosuppressive function in vivo. These therapeutic potentials were at least in part due to their differences in HGF and CD200 expression, respectively. Conclusions We conclude that MSC origins may have significant impact on the therapeutic potentials of such cells, and should be taken into consideration in clinical applications. PMID:24721710

2014-01-01

122

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

PubMed Central

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

2013-01-01

123

Potential Climatic Impacts and Reliability of Very Large-Scale Wind Farms  

E-print Network

Meeting future world energy needs while addressing climate change requires large-scale deployment of low or zero greenhouse gas (GHG) emission technologies such as wind energy. The widespread availability of wind power has ...

Prinn, Ronald G.

124

The potential of large-scale open-sea cultivation of benthic algae  

Microsoft Academic Search

There is an area of open water about 200 miles long and 20 miles wide along the Florida Gulf coast that is eminently adapted to large-scale mariculture of tropical benthic algae. It is suggested that this is a unique area for the development of a large-scale system of planting, harvesting, and processing certain fast-growing tropical marine algae of value as

H. J. Humm

1979-01-01

125

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

PubMed

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

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

2013-07-01

126

Relationship between visual evoked potentials and subjective differences between emotional expressions in "face diagrams".  

PubMed

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 in response to presentation of a single stimulus bearing a face image, visual evoked potentials in the present study were recorded as the response to instantaneous substitution of a reference stimulus with a test stimulus, and thus represented the direct response to the difference between the stimuli. A characteristic of this approach was the use of a series of functionally associated test stimuli, in which there was a monotonic increase in the difference between the test and references images in terms of the variable characteristics of the stimuli. Analysis revealed differences in the amplitudes of the P120, N180, and P230 peaks in leads O1, O2, P3, P4, T5, and T6, which demonstrated high levels of correlation both with a points-scale assessment of perceived differences between the emotional expressions of faces and with the physical (configurative) differences between images of the same faces as defined by the differences in the orientation angles of lines determining mouth curvature and brow angle. Responses were seen to differences between stimuli for both types of change in pairs of images, both going from reference image to test image and from test image to reference image. Changes in the interpeak amplitude of the P120-N180 potential in the temporal areas of both hemispheres provided the earliest electrophysiological measure of perceived differences between the emotional expressions of human faces. This suggests application of the spherical model for the perception of emotions to specify emotional facial expressions in terms of the activity of line orientation detectors. PMID:11693478

Izmailov ChA; Korshunova, S G; Sokolov, E N

2001-01-01

127

Potential Climatic Impacts and Reliability of Large-Scale Offshore Wind Farms  

E-print Network

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 ...

Wang, Chien

128

Sex differences of event-related potential effects during three-dimensional mental rotation.  

PubMed

Sex differences in performance and in cortical activation patterns during mental rotation have rather consistently been reported. Data regarding sex differences of event-related potentials during the classic three-dimensional mental rotation task developed by Shepard and Metzler, however, are absent, and were therefore being addressed by this study. Mental rotation-related event-related potential effects were observed 900-1000 ms poststimulus at parietal electrodes and 600-700 as well as 800-900 ms poststimulus at right frontal leads, respectively. Sex differences, however, were observed already 400-700 ms poststimulus at right frontal electrodes. These findings suggest that sex differences during three-dimensional mental rotation occurred in relatively early cognitive processing stages presumably including perception and identification of stimuli instead of mental rotation itself. PMID:19057281

Yu, Qingbao; Tang, Yiyuan; Li, Jian; Lu, Qilin; Wang, Huili; Sui, Danni; Zhou, Li; Wang, Yan; Heil, Martin

2009-01-01

129

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

E-print Network

Analysis of the Potential for a Heat Island Effect in Large Solar Farms Vasilis Fthenakis1, thus, it is unlikely that a heat island effect could occur. Work is in progress to approximate the flow penetration into regional and global grids. Index Terms ­ PV, climate change, heat island, fluid dynamics I

130

Comparison of the solar energy utilisation potential of different urban environments  

Microsoft Academic Search

Besides a more efficient energy use, large scale application of solar energy technologies in the urban context will be necessary in the upcoming decades to achieve a drastic reduction of greenhouse gas emissions in the biosphere. Two different urban sites, representative of two of the largest Swiss cities (Basel and Geneva), were examined under this aspect in order to assess

M Montavon; J-L Scartezzini; R Compagnon

131

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

PubMed

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

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

2014-06-01

132

Hippocampal long-term depression and long-term potentiation encode different aspects of novelty acquisition  

Microsoft Academic Search

The hippocampus is required for encoding spatial information. Little is known however, about how different attributes of learning are related to different types of synaptic plasticity. Here, we investigated the association between long-term depression (LTD) and long-term potentiation, both cellular models for learning, and novelty exploration. We found that exploration of a new environment containing unfamiliar objects and\\/or familiar objects

Anne Kemp; Denise Manahan-Vaughan

2004-01-01

133

On the Potential of Norm-Governed Behavior in Different Categories of Artificial Societies  

Microsoft Academic Search

Based on a classification of artificial societies and the identification of four different types of stakeholders in such societies,\\u000a we investigate the potential of norm-governed behavior in different types of artificial societies. The basis of the analysis\\u000a is the preferences of the stakeholders and how they influence the state of the society. A general conclusion drawn is that\\u000a the more

Paul Davidsson; Stefan J. J. Johansson

2005-01-01

134

Tetraploid and hexaploid wheat varieties reveal large differences in expression of alpha-gliadins from homoeologous Gli-2 loci  

PubMed Central

Background ?-gliadins form a multigene protein family encoded by multiple ?-gliadin (Gli-2) genes at three genomic loci, Gli-A2, Gli-B2 and Gli-D2, respectively located on the homoeologous wheat chromosomes 6AS, 6BS, and 6DS. These proteins contain a number of important celiac disease (CD)-immunogenic domains. The ?-gliadins expressed from the Gli-B2 locus harbour fewer conserved CD-epitopes than those from Gli-A2, whereas the Gli-D2 gliadins have the highest CD-immunogenic potential. In order to detect differences in the highly CD-immunogenic ?-gliadin fraction we determined the relative expression level from the homoeologous Gli-2 loci in various tetraploid and hexaploid wheat genotypes by using a quantitative pyrosequencing method and by analyzing expressed sequence tag (EST) sequences. Results We detected large differences in relative expression levels of ?-gliadin genes from the three homoeologous loci among wheat genotypes, both as relative numbers of expressed sequence tag (EST) sequences from specific varieties and when using a quantitative pyrosequencing assay specific for Gli-A2 genes. The relative Gli-A2 expression level in a tetraploid durum wheat cultivar ('Probstdorfer Pandur') was 41%. In genotypes derived from landraces, the Gli-A2 frequency varied between 12% and 58%. In some advanced hexaploid bread wheat cultivars the genes from locus Gli-B2 were hardly expressed (e.g., less than 5% in 'Lavett') but in others they made up more than 40% (e.g., in 'Baldus'). Conclusion Here, we have shown that large differences exist in relative expression levels of ?-gliadins from the homoeologous Gli-2 loci among wheat genotypes. Since the homoelogous genes differ in the amount of conserved CD-epitopes, screening for differential expression from the homoeologous Gli-2 loci can be employed for the pre-selection of wheat varieties in the search for varieties with very low CD-immunogenic potential. Pyrosequencing is a method that can be employed for such a 'gene family-specific quantitative transcriptome profiling'. PMID:19171027

Salentijn, Elma MJ; Goryunova, Svetlana V; Bas, Noor; van der Meer, Ingrid M; van den Broeck, Hetty C; Bastien, Thomas; Gilissen, Luud JWJ; Smulders, Marinus JM

2009-01-01

135

Measurement of magnetic field aligned potential differences using high resolution conjugate photoelectron energy spectra  

NASA Technical Reports Server (NTRS)

Simultaneous high-resolution observations of a distinctive feature in the energy spectrum of conjugate photoelectrons and spacecraft potential relative to the local ionosphere have allowed the net potential difference between magnetic conjugate points at latitudes below the region of low-energy (i.e., lower than 100 eV) auroral electron precipitation to be determined. Measurements made at 300 km from Atmosphere Explorer C show that there is normally no net potential difference between hemispheres in this region, which extended up to invariant latitudes as high as 74 deg. Two types of apparently related anomalous behavior were infrequently observed at high latitudes. During these periods the incident flux of conjugate photoelectrons was either decelerated by about 3 eV or was not detected.

Peterson, W. K.; Doering, J. P.; Potemra, T. A.; Bostrom, C. O.; Brace, L. H.; Heelis, R. A.; Hanson, W. B.

1977-01-01

136

Implicit Large Eddy Simulation of Flow over a Corrugated Dragonfly Wing Using High-Order Spectral Difference Method  

NASA Astrophysics Data System (ADS)

Implicit large eddy simulations of flow over a corrugated dragonfly wing at a Reynolds number of 34,000 at high angles of attack have been investigated with a high-order unstructured spectral difference Navier-Stokes solver. The computational results are compared with a recent experimental study by Hu et al. Both 2D and 3D simulations are carried out to assess how realistic and reliable the 2D simulations are in comparison with 3D simulations. At the angle of attack of 16 degrees, the 2D simulation failed to predict the stall observed in the experiment, while the 3D simulation correctly predicted the stall. In addition, the 3D simulation predicted a mean lift coefficient within 5% of the experimental data. We plan to compute at least another angle of attack and compare with the experimental data. The numerical simulations demonstrated the potential of the high-order SD method in large eddy simulation of physically complex problems.

Wang, Z. J.

2009-11-01

137

Limits of Event-related Potential Differences in Tracking Object Processing Speed  

Microsoft Academic Search

We report results from two experiments in which subjects had to categorize briefly presented upright or inverted natural scenes. In the first experiment, subjects decided whether im- ages contained animals or human faces presented at different scales. Behavioral results showed virtually identical process- ing speed between the two categories and very limited effects of inversion. One type of event-related potential

Guillaume A. Rousselet; Marc J.-M. Macé; Simon J. Thorpe; Michèle Fabre-thorpe

2007-01-01

138

How to Help Children with Learning Differences Reach Their Full Potential  

ERIC Educational Resources Information Center

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…

Lavoie, Theresa

2008-01-01

139

The shape of human atrial action potential accounts for different frequency-related changes in vitro  

Microsoft Academic Search

We aimed at investigating frequency-related changes of human atrial action potential (AP) in vitro to see whether baseline AP shape might account for different responses to increasing stimulation rates. Human right atrial trabeculae (n = 48) obtained from adult (n = 38, mean age 59 ± 8, range 45–72 years) consecutive patients (?30% of those operated upon by a single

Amos Adeyemo Dawodu; Francesco Monti; Katsunori Iwashiro; Michele Schiariti; Roberta Chiavarelli; Paolo Emilio Puddu

1996-01-01

140

Electrical potential difference and sodium and potassium fluxes across rectal mucosa in ulcerative colitis  

Microsoft Academic Search

The transmucosal electrical potential difference (pd) and the sodium and potassium flux rates (using a dialysis method) have been measured in the rectum and distal sigmoid colon of patients with ulcerative colitis and compared with measurements made in individuals having normal bowel function. In active colitis, a very low transmucosal pd was found and was associated with loss of the

C. J. Edmonds; Diana Pilcher

1973-01-01

141

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

Microsoft Academic Search

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

Thomas Boller; Andres Wiemken; Ian R. Sanders

1998-01-01

142

Derivation of regional crop sequences as an indicator for potential GMO dispersal on large spatial scales  

Microsoft Academic Search

A methodological approach is presented which aims to visualise the constraints for crop sequence planning in agriculture in a regional, large-scale context. In particular, the relationship between the scope of oilseed rape cultivation and the overall regional cropping structure, the share of particular farm types and the interactions between single crops have been analysed. The identified constraints have been applied

Michael Glemnitz; Angelika Wurbs; Reinhold Roth

2011-01-01

143

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

Microsoft Academic Search

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

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

2011-01-01

144

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

PubMed

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

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

2014-08-01

145

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

PubMed

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

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

2012-05-01

146

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

PubMed

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

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

1996-01-01

147

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

NASA Technical Reports Server (NTRS)

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.

Berton, Jeffrey J.

2000-01-01

148

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

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

149

The Effective Group Potential, a New Method for the Study of Spectrum in Large Molecules: Tests and Perspectives  

SciTech Connect

The new method, called effective group potential, which generalizes the concept of effective core potential by including in a potential the effects of many atoms ligand, is used to calculate transition energies. Three molecules containing a metal atom (Cu, Cr, Ni) surrounded by NH3 ligands have been studied. It is shown that by replacing the NH3 group by an effective group potential, the characteristic transitions energies are very well reproduced at various ab initio levels. The transitions studied are transitions between open shells on the metallic center but also ligand to metal transitions where, though unexpected, quite reliable results were also obtained. This method is thus very well suited for the study of the spectrum of a large molecule under the condition that a separation between an active part plus some spectator groups can be made, a condition satisfied in most organometallic molecules as well as in biological molecules.

Heully, Jean-Louis; Poteau, Romuald; Berasaluce, Sandra; Alary, Fabienne

2002-03-22

150

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

Microsoft Academic Search

BackgroundClinically significant drug-drug interactions (CSDIs) involving antiretrovirals are frequent and under-recognized in developed countries, but data are lacking for developing countries.Methodology and Principal FindingsTo investigate the prevalence of CSDIs between antiretrovirals and coadministered drugs, we surveyed prescriptions dispensed in a large HIV clinic in Kenya. Of 1040 consecutive patients screened, 996 were eligible for inclusion. CSDIs were defined as ‘major’

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

2011-01-01

151

Detection potential for the diffuse supernova neutrino background in the large liquid-scintillator detector LENA  

NASA Astrophysics Data System (ADS)

The large-volume liquid-scintillator detector LENA (low energy neutrino astronomy) will provide high-grade background discrimination and enable the detection of diffuse supernova neutrinos (DSN) in an almost background-free energy window from ˜10 to 25 MeV. Within ten years of exposure, it will be possible to derive significant constraints on both core-collapse supernova models and the supernova rate in the near universe up to redshifts z<2.

Wurm, M.; von Feilitzsch, F.; Göger-Neff, M.; Hochmuth, K. A.; Undagoitia, T. Marrodán; Oberauer, L.; Potzel, W.

2007-01-01

152

Potential large woody debris sources in riparian buffers after harvesting in Oregon, U.S.A  

Microsoft Academic Search

Twenty-one riparian buffers on private lands in Oregon were measured after harvest using the 1994 revised Oregon Forest Practices Rules to determine their ability to contribute large woody debris (LWD) to streams for fish habitat. On average, 51% of the trees retained in riparian buffers after harvest currently would be capable of adding debris at least 20cm diameter and 1.5m

Anne B. Hairston-Strang; Paul W. Adams

1998-01-01

153

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

USGS Publications Warehouse

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.

Graham, T. B.; Wirth, D.

2008-01-01

154

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

PubMed Central

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

Mojumder, Deb Kumar; Toledo, John De

2014-01-01

155

A microsatellite linkage map of rainbow trout (Oncorhynchus mykiss) characterized by large sex-specific differences in recombination rates.  

PubMed Central

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 identify and confirm some previously reported pseudolinkage arrangements based upon allozyme markers. Fifteen centromeric regions (20 chromosome arms) were identified with a half-tetrad analysis using gynogenetic diploids. Female map length is approximately 10 M, but this is a large underestimate as many genotyped segments remain unassigned at a LOD threshold of 3.0. Extreme differences in female:male map distances were observed (ratio F:M, 3.25:1). Females had much lower recombination rates (0.14:1) in telomeric regions than males, while recombination rates were much higher in females within regions proximal to the centromere (F:M, 10:1). Quadrivalent formations that appear almost exclusively in males are postulated to account for the observed differences. PMID:10880492

Sakamoto, T; Danzmann, R G; Gharbi, K; Howard, P; Ozaki, A; Khoo, S K; Woram, R A; Okamoto, N; Ferguson, M M; Holm, L E; Guyomard, R; Hoyheim, B

2000-01-01

156

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

NASA Astrophysics Data System (ADS)

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

Biavati, Gionata; Feist, Dietrich G.

2014-05-01

157

The process and potential of nitrate attenuation in the aquifers with different scale of flow system  

NASA Astrophysics Data System (ADS)

Nitrate (NO3-) is a widespread pollutant derived from human activities. Many studies have confirmed that agricultural practices such as fertilizer application have resulted in nitrate contamination of groundwater (Burt et al., 1993; Mueller et al., 1995; Böhlke, 2002). Also in the developing megacities, groundwater pollution by nitrate is a severe environmental problem because of the huge amount of domestic and industrial wastewater (Onodera et al., 2008; Umezawa et al., 2008). For the sustainable use of groundwater resources for the future, it is important to clarify about the natural function of nitrate attenuation such as denitrification process in groundwater. The previous studies have shown the nitrate attenuation by denitrification process in groundwater of the riparian wetlands (Hill et al., 2000; Böhlke et al., 2002), floodplain (Fustec et al., 1991; Tesoriero et al., 2000) or coastal area (Howard, 1985; Uchiyama et al., 2000) with relatively gentle topographic gradient. In recent years, several researchers have suggested that landscape hydrogeology can provide an important framework for understanding nitrate removal capacity at the riparian zones (Hill, 1996; Baker et al., 2001; Vidon & Hill, 2004). However, few studies discussed about the relation between groundwater flow condition and denitrification process on the catchment scales. The objective this study is to examine the process and potential of nitrate attenuation in the aquifers with the different scale of flow system. We compared the data on the groundwater flow, nitrate concentration and nitrogen stable isotope ratio (?15N) in groundwater in the three study sites (IK, YD and JK). All these study areas are characterized by the large nitrogen load from agricultural, domestic and industrial activities. The IK (Ikuchijima) aquifer is located in southern Japan with the catchment area of 44ha and topographic gradient of 1/50. The YD (Yellow River Delta) aquifer is located on the lower reaches of the Yellow River, which covers approximately 5200km2 and topographic gradient is approximately 1/1000. The JK (Jakarta) aquifer is located on the metropolitan area of Jakarta that is lower reaches of the Ciliwung River catchment and the topographic gradient is approximately 1/400. In the all study sites, NO3--N attenuation with the groundwater flow was confirmed, and groundwater in the recharge area is characterized by relatively high concentrations of NO3--N and relatively low ?15N, while the groundwater of the discharge area is characterized by relatively low concentrations of NO3--N and relatively high ?15N. This result suggests isotope enrichment by denitrification process. Especially in the YD, isotope enrichment ratio is higher than the other two sites.

Saito, M.; Onodera, S.

2009-12-01

158

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

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

159

The effect of siblings on early development: a potential contributor to personality differences in mammals.  

PubMed

Although most mammals grow up in the company of same or different age sibs (or half sibs), surprisingly little attention has been given to how relations among them might influence the development of individual differences in morphology, physiology, and behavior. Here we review evidence from our work on domestic and wild European rabbits, and more recently on laboratory rats, mice, and domestic cats, supporting the proposition that in mammals early sibling relations contribute to the development of individual differences in these three domains and thereby to long-term behavioral differences of the kind we might consider part of an animal's behavioral style or personality. First we report a consistent and marked negative relation between litter size and individuals' body mass at birth and weaning, as well as marked within-litter differences in prenatal body mass and placental efficiency. We then report individual differences in preweaning behaviors associated with these morphological variables such as position occupied in the litter huddle and development of motor ability, as well as physiological differences in thermoregulation, immune parameters, and endocrine indicators of stress. Finally, we report first evidence from wild rabbits that early relations among littermates may have long-term consequences for individual differences in behavioral style. We conclude that in mammals, individual differences in early growth, physiology and behavior potentially important for the development of animal personality, are shaped to an appreciable extent by early sibling relations and that this little-researched field deserves closer attention. PMID:21866540

Hudson, Robyn; Bautista, Amando; Reyes-Meza, Verónica; Montor, Jorge Morales; Rödel, Heiko G

2011-09-01

160

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

SciTech Connect

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

Not Available

2011-10-01

161

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

NASA Astrophysics Data System (ADS)

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.

Hicks, M.; Ebelhar, S.

2013-11-01

162

Analysis of gender based differences in auditory evoked potentials among healthy elderly population  

PubMed Central

Background: Influence of gender on auditory evoked potentials is contentious. Although there are quite a few studies documenting the gender as an influencing factor on auditory evoked potentials in younger subjects, but there is a lack of similar studies among elderly population. The present study was conducted to find out the pattern of gender based differences in auditory evoked potentials among healthy elderly subjects. Materials and Methods: A cross-sectional study was conducted on age matched, healthy males (n = 35) and females (n = 34), aged 50-70 years. The measures included latencies of waves I-V and interpeak latencies (IPL) I-III, III-V and I-V separately for both ears. Data was analyzed statistically using Students unpaired t-test, using Statistical Package for Social Sciences software v13.0. Results: The values of all the latencies and IPL for both the ears were non-significantly higher (P > 0.05) in males as compared to females. These results may be attributed to the differences in head circumference between both the genders and to the changed hormonal milieu of sex hormones after menopause. Conclusions: Statistical insignificance of latencies among male and female elderly subjects excludes gender as an influencing factor on auditory evoked potentials in this age group. PMID:25371865

Gupta, Sharat; Mittal, Shallu; Baweja, Pooja; Kumar, Avnish; Singh, Kamal Dev; Sharma, Raghuvansh

2014-01-01

163

Sex differences in event-related potential components during the solution of complex mental rotation tasks.  

PubMed

The objective of the study was to evaluate the factor of sex in terms of its influence on event-related potential components during the solution of a complex mental rotation task. To evaluate the factor of sex, independent of differences in ability levels and hormonal changes, women and men were equalized with respect to general intelligence and spatial ability. In addition, all women were tested during the low-estrogen phase of the menstrual cycle. The event-related potential analysis indicated that men showed shorter P3 and longer P1 latencies, as well as lower N1 amplitudes. These results suggest that men devoted more time to the analysis of irrelevant information presented in the rotation tasks, which resulted in mental rotation taking place earlier in men than in women. It can be concluded that, even though men and women showed similar performances on complex rotation tasks, they differed in their solution processes. PMID:22357397

Jaušovec, Norbert

2012-04-18

164

Torque measurements reveal large process differences between materials during high solid enzymatic hydrolysis of pretreated lignocellulose  

PubMed Central

Background A common trend in the research on 2nd generation bioethanol is the focus on intensifying the process and increasing the concentration of water insoluble solids (WIS) throughout the process. However, increasing the WIS content is not without problems. For example, the viscosity of pretreated lignocellulosic materials is known to increase drastically with increasing WIS content. Further, at elevated viscosities, problems arise related to poor mixing of the material, such as poor distribution of the enzymes and/or difficulties with temperature and pH control, which results in possible yield reduction. Achieving good mixing is unfortunately not without cost, since the power requirements needed to operate the impeller at high viscosities can be substantial. This highly important scale-up problem can easily be overlooked. Results In this work, we monitor the impeller torque (and hence power input) in a stirred tank reactor throughout high solid enzymatic hydrolysis (< 20% WIS) of steam-pretreated Arundo donax and spruce. Two different process modes were evaluated, where either the impeller speed or the impeller power input was kept constant. Results from hydrolysis experiments at a fixed impeller speed of 10 rpm show that a very rapid decrease in impeller torque is experienced during hydrolysis of pretreated arundo (i.e. it loses its fiber network strength), whereas the fiber strength is retained for a longer time within the spruce material. This translates into a relatively low, rather WIS independent, energy input for arundo whereas the stirring power demand for spruce is substantially larger and quite WIS dependent. By operating the impeller at a constant power input (instead of a constant impeller speed) it is shown that power input greatly affects the glucose yield of pretreated spruce whereas the hydrolysis of arundo seems unaffected. Conclusions The results clearly highlight the large differences between the arundo and spruce materials, both in terms of needed energy input, and glucose yields. The impact of power input on glucose yield is furthermore shown to vary significantly between the materials, with spruce being very affected while arundo is not. These findings emphasize the need for substrate specific process solutions, where a short pre-hydrolysis (or viscosity reduction) might be favorable for arundo whereas fed-batch might be a better solution for spruce. PMID:22867035

2012-01-01

165

Mineralization of Hormones in Breeder and Broiler Litters at Different Water Potentials and Temperatures  

Microsoft Academic Search

When poultry litter is landspread, steroidal hormones present in the litter may reach surface waters, where they may have undesirable biological effects. In a laboratory study, we determined the mineral- ization of (4- 14 C)-labeled 17b-estradiol, estrone, and testosterone in breeder litter at three different water potentials (256, 224, and 212 MPa) and temperatures (25, 35, and 45C), and in

Sarah N. J. Hemmings; Peter G. Hartel

2006-01-01

166

The Flood Characteristics of Large U.K. Rivers: Potential Effects of Changing Climate and Land Use  

Microsoft Academic Search

A continuous flow simulation model(CLASSIC) has been used to assess the potential impactof climate and land use changes on the flood regimesof large U.K. catchments. Climate change scenarios,based on the HadCM2 experiments from the HadleyCentre, are applied to the Severn and Thames rivers.The analysis shows that, for the 2050s, the climatechange scenarios result in an increase in both thefrequency and

N. S. Reynard; C. Prudhomme; S. M. Crooks

2001-01-01

167

Frequency Spectrum of Transepithelial Potential Difference Reveals Transport-Related Oscillations  

PubMed Central

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

Montalbetti, Nicolás; Fischbarg, Jorge

2009-01-01

168

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

SciTech Connect

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.

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

2007-01-01

169

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

NASA Astrophysics Data System (ADS)

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.

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

2012-07-01

170

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

171

Differences in PAR-2 activating potential by king crab (Paralithodes camtschaticus), salmon (Salmo salar), and bovine (Bos taurus) trypsin  

PubMed Central

Background Salmon trypsin is shown to increase secretion of the pro-inflammatory cytokine interleukin (IL)-8 from human airway epithelial cells through activation of PAR-2. Secretion of IL-8 induced by king crab trypsin is observed in a different concentration range compared to salmon trypsin, and seems to be only partially related to PAR-2 activation. This report aim to identify differences in the molecular structure of king crab trypsin (Paralithodes camtschaticus) compared to salmon (Salmo salar) and bovine trypsin (Bos taurus) that might influence the ability to activate protease-activated receptor-2 (PAR-2). Results During purification king crab trypsin displayed stronger binding capacity to the anionic column used in fast protein liquid chromatography compared to fish trypsins, and was identified as a slightly bigger molecule. Measurements of enzymatic activity yielded no obvious differences between the trypsins tested. Molecular modelling showed that king crab trypsin has a large area with strong negative electrostatic potential compared to the smaller negative areas in bovine and salmon trypsins. Bovine and salmon trypsins also displayed areas with strong positive electrostatic potential, a feature lacking in the king crab trypsin. Furthermore we have identified 3 divergent positions (Asp196, Arg244, and Tyr247) located near the substrate binding pocket of king crab trypsin that might affect the binding and cleavage of PAR-2. Conclusion These preliminary results indicate that electrostatic interactions could be of importance in binding, cleavage and subsequent activation of PAR-2. PMID:23870109

2013-01-01

172

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

PubMed

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

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

2003-01-01

173

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

174

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

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

175

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

USGS Publications Warehouse

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

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

2010-01-01

176

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

PubMed Central

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

2011-01-01

177

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

PubMed

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

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

2014-01-01

178

Assessing different zeolitic adsorbents for their potential use in Kr and Xe separation  

NASA Astrophysics Data System (ADS)

Separation of Kr from Xe is an important problem in spent nuclear fuel fission gas management. The energy intensive and expensive cryogenic distillation method is currently used to separate these gases. In this thesis, we have carried out the research into appropriate sorbents for the separation of Kr and Xe using pressure swing adsorption. We have examined zeolites using gas adsorption studies as they have the potential to be more cost effective than other sorbents. Zeolites are microporous aluminosilicates and have ordered pore structures. The pores in zeolites have extra-framework cations are substantially free to move. The mobility of cations and the uniformity in pore size permits the separation and removal of gases in zeolites. In our experiment, first, we have measured adsorption isotherms with same zeolitic framework but with different cations. Second, we have measured the adsorption isotherm with different zeolitic frameworks but with same cation. Using these adsorption isotherms, we have calculated the initial heats of adsorption to find out the strength of interaction between the zeolitic framework and the gases. Finally, we have compared the difference in the initial heats of adsorption to find the suitable zeolite that has the highest selectivity of Xe over Kr. In conclusion, we have found out that K LSX seems to have higher potential among the zeolites that we have compared for the separation of Kr from Xe with the differential heats of adsorption for Xe vs Kr as ˜7.4 kJ/mol.

Alagappan, Breetha

179

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

SciTech Connect

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

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

2011-04-18

180

Profiles in fibromyalgia: algometry, auditory evoked potentials and clinical characterization of different subtypes.  

PubMed

The heterogeneity found in fibromyalgia (FM) patients has led to the investigation of disease subgroups, mainly based on clinical features. The aim of this study was to test the hypothesis that clinical FM subgroups are associated with different underlying pathophysiological mechanisms. Sixty-three FM patients were classified in type I or type II, according to the Fibromyalgia Impact Questionnaire (FIQ), and in mild/moderate versus severe FM, according to the severity of three cardinal symptoms considered in the American College of Rheumatology (ACR) 2010 criteria (unrefreshed sleep, cognitive problems and fatigue). To validate the subgroups obtained by these two classifications, we calculated the area under the receiver operating characteristic curves for various clinical variables and for two potential biomarkers of FM: Response to experimental pressure pain (algometry) and the amplitude/intensity slopes of the auditory evoked potentials (AEPs) obtained to stimuli of increasing intensity. The variables that best discriminated type I versus type II were those related to depression, while the indices of clinical or experimental pain (threshold or tolerance) did not significantly differ between them. The variables that best discriminated the mild/moderate versus severe subgroups were those related to the algometry. The AEPs did not allow discrimination among the generated subsets. The FIQ-based classification allows the identification of subgroups that differ in psychological distress, while the index based on the ACR 2010 criteria seems to be useful to characterize the severity of FM mainly based on hyperalgesia. The incorporation of potential biomarkers to generate or validate classification criteria is crucial to advance in the knowledge of FM and in the understanding of pathophysiological pathways. PMID:24723098

Triñanes, Yolanda; González-Villar, Alberto; Gómez-Perretta, Claudio; Carrillo-de-la-Peña, María T

2014-11-01

181

Perceived differences in tutor grading in large classes: Fact or fiction?  

Microsoft Academic Search

For many years the authors have coordinated a large engineering design subject, having a cohort of approximately 300+ students. Lectures are supported by tutorials of approximately 32 students which incorporate collaborative team learning activities and project-based learning. Each tutor is responsible for grading the assessment tasks for students in their tutorial. A common issue is how to achieve a consistent

Keith Willey; Anne Gardner

2010-01-01

182

A simple and reproducible method to obtain large numbers of axenic amastigotes of different Leishmania species  

Microsoft Academic Search

This work describes a simple method to yield large amounts of Leishmania amastigote-like forms in axenic cultures using promastigotes as the starting population. The method described induced extracellular amastigote transformation of Leishmania amazonensis (97%), Leishmania braziliensis (98%) and Leishmania chagasi (90%). The rounded parasites obtained in axenic cultures were morphologically similar, even at the ultrastructural level, to intracellular amastigotes. Moreover,

Márcia Teixeira; Regilene de Jesus Santos; Romina Barreto Sampaio; Lain Pontes-de-Carvalho; Washington L. dos-Santos

2002-01-01

183

Different strains of rats show different sensitivity to block of long-term potentiation by nitric oxide synthase inhibitors  

Microsoft Academic Search

Nitric oxide is presumed to play important roles in the induction of synaptic plasticity and learning. Previous publications, however, reported contradictory results. Block of nitric oxide synthase (NOS) has been shown to impair the induction of long-term potentiation of synaptic transmission in some studies. Other studies observed a partial block of long-term potentiation depending on experimental conditions, while yet other

Christian Hölscher

2002-01-01

184

[Comparison of steady-state visually evoked potential evoked by different monochromatic light].  

PubMed

The cone cell on the retina of human is the sensor of vision under illumination; it can be classified into three types: red cone cell, green cone cell, and blue cone cell. There is different property of absorbing light for each type of cone cell. In this work, a 10 Hz pulse was used to drive red, green and blue light emitting diodes respectively, and the different monochromatic light with the same luminance was obtained. The eyes of ten subjects were stimulated by different monochromatic light independently; an EGI system with 128 channels was used to record the steady-state visually evoked potential (SSVEP). After applying the fast fourier transform (FFT) to the SSVEP data, we found that the distribution of the neural network in the initial vision cortex activated by the output of the different-typed cone cell remained mainly identical, but there was some difference in intensity between the three types of network: the activity by blue light is the strongest one, that by red light is in the middle, and that by green light is the weakest one. PMID:19024438

Wu, Zhenghua; Yao, Dezhong

2008-10-01

185

Sex Differences in Intellectual Performance: Analysis of a Large Cohort of Competitive Chess Players  

Microsoft Academic Search

Only 1% of the world's chess grandmasters are women. This underrepresentation is unlikely to be caused by discrimination, because chess ratings objectively reflect competitive results. Using data on the ratings of more than 250,000 tournament players over 13 years, we investigated several potential explanations for the male domination of elite chess. We found that (a) the ratings of men are

Christopher F. Chabris; Mark E. Glickman

2006-01-01

186

How large are cognitive gender differences? A meta-analysis using !w² and ^I d  

Microsoft Academic Search

E. E. Maccoby and C. N. Jacklin (1974) concluded that the following cognitive gender differences were well-established: verbal ability, quantitative ability, and visual–spatial ability. The present study applied meta-analysis techniques to studies cited by Maccoby and Jacklin, assessing the magnitude of gender differences using both |w–2 and d statistics. Results indicate that gender differences in all of these abilities were

Janet S. Hyde

1981-01-01

187

Quantitative proteome analysis of HCC cell lines with different metastatic potentials by SILAC.  

PubMed

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and metastasis is the main cause for treatment failure and high fatality of HCC. In order to make further exploration into the mechanism of HCC metastasis and to search for the candidates of diagnostic marker and therapeutic target, stable-isotope labeling by amino acids in cell culture (SILAC) technique was employed to conduct differential proteome analysis on HCC cell lines--MHCC97L and HCCLM6 with low and high metastatic potentials. In total, 2335 reliable proteins were identified using LTQ-FT mass spectrum, among which 91 proteins were upregulated and 61 proteins were downregulated in HCCLM6. Most of the upregulated proteins were involved in adherence, morphogenesis, and lipid synthesis, while lots of the downregulated proteins were involved in electron transport, which might be crucial for HCC metastasis. Six dysregulated proteins were validated by Western blotting in the cell lines. Interestingly, the upregulation of solute carrier family 12 member 2 (SLC 12A2) and protein disulfide-isomerase A4 (PDIA4) were further confirmed in the culture supernatants by Western blotting and in the sera of HCC patients with different metastatic potentials by ELISA. Our study provided not only the valuable insights into the HCC metastasis mechanisms but also the potential candidate biomarkers for prediction of HCC metastasis. PMID:19016532

Chen, Ning; Sun, Wei; Deng, Xinyu; Hao, Yunwei; Chen, Xilin; Xing, Baocai; Jia, Wei; Ma, Jie; Wei, Handong; Zhu, Yunping; Qian, Xiaohong; Jiang, Ying; He, Fuchu

2008-12-01

188

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

189

Quercetin Potentiates the Antitumor Activity of Rituximab in Diffuse Large B-Cell Lymphoma by Inhibiting STAT3 Pathway.  

PubMed

STAT3 pathway plays an important role in the growth of diffuse large B-cell lymphoma (DLBCL) cells. Here we investigated the antitumor activity of Quercetin, a flavonoid compound, in combination with rituximab in DLBCL cell lines in vitro. We found that Quercetin synergistically enhanced rituximab-induced growth inhibition and apoptosis in DLBCL cell lines. Moreover, we found Quercetin exerted inhibitory activity against STAT3 pathway and downregulated the expression of survival genes. These results suggest that combining the Quercetin with rituximab may present an attractive and potentially effective way for the treatment of DLBCL. PMID:24902540

Li, Xin; Wang, Xinhua; Zhang, Mingzhi; Li, Aimin; Sun, Zhenchang; Yu, Qi

2014-11-01

190

Public concern about chemicals in the environment: Regional differences based on threat potential  

SciTech Connect

While the hazards of chronic environmental pollution remain unclear, people are making decisions about their exposure to pollution and its possible effects on their health. To compare people's concerns about environmental problems, a systematic, stratified sample was surveyed. The sample was made up of residents, ages 25 through 74 years, of three areas of New York State. The three areas were western New York, with a high density of toxic dump sites; Long Island, with a major shallow ground water aquifer; and the remainder of the State, excluding New York City, as a comparison area. The sampling list was obtained from records of licensed drivers of the New York State Department of Motor Vehicles. A 66 percent response rate was obtained to the mailed survey. As expected, most concerns were greater for western New York and Long Island, the two areas with highest threat potential for exposure or contamination, than for the comparison area. The single exception was that no regional differences were noted for concerns about environmental pollution and contamination. All concerns were associated with perceived distance between one's residence and a source of potential exposure. Regardless of region, women were more concerned than men about exposures, pollution, and related health effects. No sex differences, however, were noted for economic concerns.

Howe, H.L. (Illinois Department of Public Health, Springfield (USA))

1990-03-01

191

The role of the transbranchial potential difference in hyperosmotic regulation of the shore crab Carcinus maenas  

NASA Astrophysics Data System (ADS)

When isolated gills of the shore crab Carcinus maenas were bathed and perfused with identical solutions on both sides (50 % sea water), a spontaneous transepithelial potential difference (PD) of some millivolts (hemolymph side negative) was established. This PD is of active nature and requires the metabolism of the living cell, since it uses its own sources of energy in addition to organic nutrients offered in the flow of artificial hemolymph. Addition of sodium cyanide and dinitrophenole to bathing and perfusion medium resulted in reversible breakdown of PDs in a concentration-dependent mode. In posterior gills of C. maenas, the potential differences were more negative compared to data measured in anterior gills of the same individuals. These results are correlated with higher specific activities of Na-K-ATPase in posterior gills. Experiments with triamterene indicate that sodium uptake in C. maenas is sensitive to this diuretic drug, when applied on the apical side of the epithelial cell. The results obtained show that active uptake of sodium from medium to blood across the gills is performed by a complex mechanism including participation of several basal and apical transport steps.

Winkler, Andreas

1986-03-01

192

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

NASA Technical Reports Server (NTRS)

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

Delano, John W.

1988-01-01

193

Regional Difference in Scaling Laws for Large Earthquakes and its Tectonic Implication  

Microsoft Academic Search

We compiled 67 large earthquakes which occurred at and around plate boundaries for the last 140 yrs, and classified them into four groups; interplate strike-slip events, intraplate strike-slip events, underthrust events at island-arc subduction zones, and underthrust events at continental-margin subduction zones. For each group of earthquakes we examined relations between seismic moment M0, fault length L, fault width W

Yoshihiro Fujii; M. Matsu'ura

2000-01-01

194

Decentralized Iterative Learning Controllers for Nonlinear Large-scale Systems to Track Trajectories with Different Magnitudes  

Microsoft Academic Search

In hierarchical steady-state optimization programming for large-scale industrial processes, a feasible technique is to use information of the real system so as to modify the model-based optimum. In this circumstance, a sequence of step function-type control decisions with distinct magnitudes is computed, by which the real system is stimulated consecutively. In this paper, a set of iterative learning controllers is

Xiao-E RUAN; Feng-Min CHEN; Bai-Wu WAN

2008-01-01

195

Static and temporal gravity field recovery using grace potential difference observables  

NASA Astrophysics Data System (ADS)

The gravity field dedicated satellite missions like CHAMP, GRACE, and GOCE are supposed to map the Earth's global gravity field with unprecedented accuracy and resolution. New models of Earth's static and time-variable gravity field will be available every month as one of the science products from GRACE. Here we present an alternative method to estimate the gravity field efficiently using the in situ satellite-to-satellite observations at the altitude and show results on static as well as temporal gravity field recovery. Considering the energy relation between the kinetic energy of the satellite and the gravitational potential, the disturbing potential difference observations can be computed from the orbital parameter vectors in the inertial frame, using the high-low GPS-LEO GPS tracking data, the low-low satelliteto- satellite GRACE measurements, and data from 3-axis accelerometers (Jekeli, 1999). The disturbing potential observation also includes other potentials due to tides, atmosphere, other modeled signals (e.g. N-body) and the geophysical fluid signals (hydrological and oceanic mass variations), which should be recoverable from GRACE mission with a monthly resolution. The simulation results confirm that monthly geoid accuracy is expected to be a few cm with the 160 km resolution (up to degree and order 120) once other corrections are made accurately. The time-variable geoids (ocean and ground water mass) might be recovered with a noise-to-signal ratio of 0.1 with the resolution of 800 km every month assuming no temporal aliasing.Key words. GRACE mission, Energy integral, Geopotential, Satellite-to-satellite tracking, Temporal gravity field

Han, S.-C.; Jekeli, C.; Shum, C. K.

2003-06-01

196

Repetition and brain potentials when recognizing natural scenes: task and emotion differences.  

PubMed

Repetition has long been known to facilitate memory performance, but its effects on event-related potentials (ERPs), measured as an index of recognition memory, are less well characterized. In Experiment 1, effects of both massed and distributed repetition on old-new ERPs were assessed during an immediate recognition test that followed incidental encoding of natural scenes that also varied in emotionality. Distributed repetition at encoding enhanced both memory performance and the amplitude of an old-new ERP difference over centro-parietal sensors. To assess whether these repetition effects reflect encoding or retrieval differences, the recognition task was replaced with passive viewing of old and new pictures in Experiment 2. In the absence of an explicit recognition task, ERPs were completely unaffected by repetition at encoding, and only emotional pictures prompted a modestly enhanced old-new difference. Taken together, the data suggest that repetition facilitates retrieval processes and that, in the absence of an explicit recognition task, differences in old-new ERPs are only apparent for affective cues. PMID:22842817

Ferrari, Vera; Bradley, Margaret M; Codispoti, Maurizio; Karlsson, Marie; Lang, Peter J

2013-12-01

197

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

E-print Network

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 ...

Rojas-Duran, Maria F.

198

Differences in Relative Importance of the Factors That Determine Profit in Small and Large Businesses.  

National Technical Information Service (NTIS)

The profit forecasts using FINSTAT and COMPUSTAT data show that efficiency measures most significantly predict small businesses' return on assets, while leverage and capital structure measures are most important for larger businesses. These differences ar...

D. Rothenberg

1987-01-01

199

Large impact crater histories of Mars: The effect of different model crater age techniques  

NASA Astrophysics Data System (ADS)

Impact events that produce large craters primarily occurred early in the Solar System's history because the largest bolides were remnants from planetary formation. Determining when large impacts occurred on a planetary surface such as Mars can yield clues to the flux of material in the early inner Solar System which, in turn, can constrain other planetary processes such as the timing and magnitude of resurfacing and the history of the martian core dynamo. We have used a large, global planetary database in conjunction with geomorphologic mapping to identify craters superposed on the rims of 78 larger craters with diameters D ? 150 km on Mars, ?78% of which have not been previously dated in this manner. The densities of superposed craters with diameters larger than 10, 16, 25, and 50 km, as well as isochron fits were used to derive model crater ages of these larger craters and basins from which we derived an impact flux. In discussing these ages, we point out several internal inconsistencies of crater-age modeling techniques and chronology systems and, all told, we explain why we think isochron-fitting is the most reliable indicator of an age. Our results point to a mostly obliterated crater record prior to ˜4.0 Ga with the oldest preserved mappable craters on Mars dating to ˜4.3-4.35 Ga. We have used our results to constrain the cessation time of the martian core dynamo which we found to have occurred between the formation of Ladon and Prometheus basins, approximately 4.06-4.09 Ga. We also show that, overall, surfaces on Mars older than ˜4.0-4.1 Ga have experienced >1 km of resurfacing, while those younger than ˜3.8-3.9 Ga have experienced significantly less.

Robbins, Stuart J.; Hynek, Brian M.; Lillis, Robert J.; Bottke, William F.

2013-07-01

200

Volume Reabsorption, Transepithelial Potential Differences, and Ionic Permeability Properties in Mammalian Superficial Proximal Straight Tubules  

PubMed Central

This paper describes experiments designed to evaluate Na+ and Cl- transport in isolated proximal straight tubules from rabbit kidneys. When the perfusing solution was Krebs-Ringer buffer with 25 mM HCO3- (KRB) and the bath contained KRB plus 6% albumin, net volume reabsorption (Jv, nl min-1 mm-1 was -0.46 ± 0.03 (SEM); Ve, the spontaneous transepithelial potential difference, was -1.13 ± 0.05 mV, lumen negative. Both Jv, and Ve, were reduced to zero at 21°C or with 10-4 M ouabain, but Jv, was not HCO3- dependent. Net Na+ reabsorption, measured as the difference between 22Na+ fluxes, lumen to bath and bath to lumen, accounted quantitatively for volume reabsorption, assuming the latter to be an isotonic process, and was in agreement with the difference between lumen to bath 22Na+ fluxes during volume reabsorption and at zero volume flow. The observed flux ratio for Na+ was 1.46, and that predicted for a passive process was 0.99; thus, Na+ reabsorption was rationalized in terms of an active transport process. The Cl- concentration of tubular fluid rose from 113.6 to 132.3 mM during volume reabsorption. Since Ve, rose to +0.82 mV when tubules were perfused with 138.6 mM Cl- solutions, Ve may become positive when tubular fluid Cl- concentrations rise during volume reabsorption. The permeability coefficients PNa and PCl computed from tracer fluxes were, respectively, 0.23 x 10-4 and 0.73 x 10-4 cm s-1. A PNa/PCl ratio of 0.3 described NaCl dilution potentials at zero volume flow. The magnitudes of the potentials were the same for a given NaCl gradient in either direction and PNa/PCl was constant in the range 32–139 mM NaCl. We infer that the route of passive ion permeation was through symmetrical extracellular interfaces, presumably tight junctions, characterized by neutral polar sites in which electroneutrality is maintained by mobile counterions. PMID:4443793

Schafer, James A.; Troutman, Susan L.; Andreoli, Thomas E.

1974-01-01

201

Linking admiration and adoration to self-expansion: Different ways to enhance one's potential.  

PubMed

How is admiration different from adoration? We provided one answer to this question by examining the pathways through which admiration and adoration linked to self-expansion in a questionnaire and an experimental (autobiographical recall of emotion episodes) study. Both emotions were associated with increased potential efficacy to accomplish goals (i.e., self-expansion), but different action tendencies accounted for these links. While our emotion inductions did not successfully distinguish between admiration and adoration, we could statistically disentangle their effects through mediator models. In both studies, self-reported admiration linked to self-expansion through the tendency to emulate admired others. Adoration related to self-expansion through the tendency to affiliate with adored others. These findings were obtained after controlling for other emotions in response to the target person (awe, love, hope, benign envy) and mutuality of the relationship. Our findings also suggest that considering specific emotions (rather than undifferentiated positive affect) helps uncover different pathways to self-expansion. PMID:24684656

Schindler, Ines; Paech, Juliane; Löwenbrück, Fabian

2015-02-01

202

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

SciTech Connect

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

Koch, G.W.; Randerson, J.T. (Stanford Univ. Carnegie Institution of Plant Biology, CA (United States))

1994-06-01

203

An Application of the Difference Potentials Method to Solving External Problems in CFD  

NASA Technical Reports Server (NTRS)

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.

Ryaben 'Kii, Victor S.; Tsynkov, Semyon V.

1997-01-01

204

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

NASA Astrophysics Data System (ADS)

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.

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

2011-09-01

205

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

SciTech Connect

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.

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

1996-07-01

206

A Large Gene Cluster Encoding Several Magnetosome Proteins Is Conserved in Different Species of Magnetotactic Bacteria  

Microsoft Academic Search

In magnetotactic bacteria, a number of specific proteins are associated with the magnetosome membrane (MM) and may have a crucial role in magnetite biomineralization. We have cloned and sequenced the genes of several of these polypeptides in the magnetotactic bacterium Magnetospirillum gryphiswaldense that could be assigned to two different genomic regions. Except for mamA, none of these genes have been

KAREN GRUNBERG; CATHRIN WAWER; BRADLEY M. TEBO; DIRK SCHULER

2001-01-01

207

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

ERIC Educational Resources Information Center

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

Doucet, Christine; Durand, Claire; Smith, Michael

2008-01-01

208

Differences in the Brain Stem Terminations of Large and Small Diameter Vestibular Primary Afferents  

Microsoft Academic Search

SUMMARY AND CONCLUSIONS 1. We visualized the central axons of 32 vestibular afferents from the posterior canal by extracellular application of horseradish peroxidase, reconstructed them in three dimensions, and quantified their morphology. Here we compare the descending limbs of cen- tral axons that differ in parent axon diameter. town, WI) provided useful data. Animal maintenance procedures have been published previously

J. A. HUWE; E. H. PETERSON

1995-01-01

209

Road safety improvement in large companies. An experimental comparison of different measures  

Microsoft Academic Search

Road accidents among professional drivers are a major problem in many companies. There are several traditional measures for improving safety, but knowledge about what measures are most effective is rather limited. The aim of the study is to compare four different measures for reducing accident involvement through changed driver behaviour. The measures are driver training, group discussions, campaigns and bonuses

Nils Petter Gregersen; Berndt Brehmer; Bertil Morén

1996-01-01

210

Organic nanoparticles from different fuel blends: in vitro toxicity and inflammatory potential.  

PubMed

Despite the well-established link between particulate vehicle emissions and adverse health effects, the biological effects produced by ultrafine particles generated from fuel combustion need to be investigated. The biological impact of nano-sized organic carbon particles in the size range 3-7?nm, obtained from an engine fuelled with a standard diesel and four diesel fuels doped with additives of commercial interest is reported. Our data showed that the number of particles?different nano-sized organic carbon particles induce cytotoxic and proinflammatory effects on the in vitro systems A549 (epithelial cells) and BEAS-2B (bronchial cells). All the fuels tested are able to induce the release of proinflammatory interleukins 8 and 6; moreover, the IC50 values show that the additives can increase the toxic potential of particles 10 times. Further analyses are therefore needed to better define the potential impact of organic ultrafine particles on human health. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25244046

Gualtieri, Maurizio; Capasso, Laura; D'Anna, Andrea; Camatini, Marina

2014-11-01

211

Comparing the Biogeochemical Potential of Hyporheic Zones Driven by Different River Morphologies  

NASA Astrophysics Data System (ADS)

Channel morphology controls the hydrodynamics of hyporheic exchange and its residence times. As a result, it also constrains the hyporheic zone's biogeochemical processes that transform carbon, nutrients, metals, and contaminants and the hyporheic zone's net effect at the local, reach and watershed scales. Previous studies of different morphologies (e.g., meanders, bars, and smaller bedforms such as dunes) have mainly focused on the amount of exchange or, if biogeochemistry was involved, have been specific to a particular morphology. In this work, we present a quantitative intercomparison of the amount of exchange, residence time distributions (RTDs), and biogeochemical potential for four channel morphologies: ripples, dunes, bars, and meander bends. To this end, simple two-dimensional conceptualizations and semi-analytical solutions for the hyporheic zone's flow and transport are used. In general, all morphologies are characterized by heavy-tail RTDs, implying long-term memory to solute inputs. We hypothesize that even though meander bends induce larger hyporheic exchange per unit length of channel and longer residence times, substrate limitations result in less biogeochemical processing when compared with the cumulative effect of multiple bedforms. The models presented are a function of geometric and physical properties easily measured or constrained with field or remote sensing data. The simplicity of this approach allows for practical calculations of the hyporheic zone's exchange and biogeochemical potential over a broad range of scenarios and morphologies, making it a useful tool for experimental design, sampling, and watershed scale assessment.

Gomez, J. D.; Harvey, J. W.

2013-12-01

212

Kinetic equivalence of transmembrane pH and electrical potential differences in ATP synthesis.  

PubMed

ATP synthase is the key player of Mitchell's chemiosmotic theory, converting the energy of transmembrane proton flow into the high energy bond between ADP and phosphate. The proton motive force that drives this reaction consists of two components, the pH difference (?pH) across the membrane and transmembrane electrical potential (??). The two are considered thermodynamically equivalent, but kinetic equivalence in the actual ATP synthesis is not warranted, and previous experimental results vary. Here, we show that with the thermophilic Bacillus PS3 ATP synthase that lacks an inhibitory domain of the ? subunit, ?pH imposed by acid-base transition and ?? produced by valinomycin-mediated K(+) diffusion potential contribute equally to the rate of ATP synthesis within the experimental range examined (?pH -0.3 to 2.2, ?? -30 to 140 mV, pH around the catalytic domain 8.0). Either ?pH or ?? alone can drive synthesis, even when the other slightly opposes. ?? was estimated from the Nernst equation, which appeared valid down to 1 mm K(+) inside the proteoliposomes, due to careful removal of K(+) from the lipid. PMID:22253434

Soga, Naoki; Kinosita, Kazuhiko; Yoshida, Masasuke; Suzuki, Toshiharu

2012-03-16

213

Chemistry and potential mutagenicity of humic substances in waters from different watersheds in Britain and Ireland  

USGS Publications Warehouse

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.

Watt, B. E.; Malcolm, R. L.; Hayes, M. H. B.; Clark, N. W. E.; Chipman, J. K.

1996-01-01

214

Difference of Diagnostic Rates and Analytical Methods in the Test Positions of Vestibular Evoked Myogenic Potentials  

PubMed Central

Objective To compare the differences of diagnostic rates, of the two widely used test positions, in measuring vestibular evoked myogenic potentials (VEMP) and selecting the most appropriate analytical method for diagnostic criteria for the patients with vertigo. Methods Thirty-two patients with vertigo were tested in two comparative testing positions: turning the head to the opposite side of the evaluating side and bowing while in seated position, and bowing while in supine positions. Abnormalities were determined by prolonged latency of p13 or n23, shortening of the interpeak latency, and absence of VEMP formation. Results Using the three criteria above for determining abnormalities, both the seated and supine positions showed no significant differences in diagnostic rates, however, the concordance correlation of the two positions was low. When using only the prolonged latency of p13 or n23 in the two positions, diagnostic rates were not significantly different and their concordance correlation was high. On the other hand, using only the shortened interpeak latency in both positions showed no significant difference of diagnostic rates, and the degree of agreement between two positions was low. Conclusion Bowing while in seated position with the head turned in the opposite direction to the area being evaluated is found to be the best VEMP test position due to the consistent level of sternocleidomastoid muscle tension and the high level of compliance. Also, among other diagnostic analysis methods, using prolonged latency of p13 or n23 as the criterion is found to be the most appropriate method of analysis for the VEMP test. PMID:24855617

Park, Jeong Mee; Yong, Sang Yeol; Kim, Jong Heon; Kim, Hee; Park, Sang-Yoo

2014-01-01

215

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

E-print Network

Large interclone differences in melezitose secretion in the facultatively ant-tended black bean online xxxx Keywords: Ant­aphid mutualism Black bean aphid Honeydew sugar composition Ant. Here we present data on clonal var- iation in the composition of honeydew of the black bean aphid Aphis

Wenseleers, Tom

216

A hybrid spectral/finite-difference large-eddy simulator of turbulent processes in the upper ocean  

E-print Network

A hybrid spectral/finite-difference large-eddy simulator of turbulent processes in the upper ocean. Smith d , J.A. MacKinnon d a Department of Civil and Environmental Engineering, University of South 2009 Elsevier Ltd. All rights reserved. 1. Introduction A parallel, hybrid spectral

Smith, Jerome A.

217

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

Microsoft Academic Search

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.(i)Epithelial resistance of colon ascendens and colon descendens was about 35 O · cm2 and not different between these two segments. It was, however, about 3 times higher in rectum (99 O ·

Jörg-Dieter Schulzke; Michael Fromm; Ulrich Hegel

1986-01-01

218

Comparison of Earth-tide parameters over a large latitude difference  

Microsoft Academic Search

Gravity Earth-tide observations at the station of Thessaloniki with a LaCoste-Romberg gravity meter equipped with electrostatic feedback were analysed in order to obtain accurate amplitude and phase-difference tidal parameters. The observations cover a total number of 162.5 days. The frequency transfer-function of our measuring system was defined using the step-response procedure. The Tamura tidal development was used as normal tidal

D. Arabelos

2002-01-01

219

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

NASA Astrophysics Data System (ADS)

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.

Arndt, Roger; Chamorro, Leonardo; Sotiropoulos, Fotis

2011-11-01

220

Intestinal Diffuse Large B-Cell Lymphoma: An Evaluation of Different Staging Systems  

PubMed Central

The gastrointestinal tract is the most common primary extranodal site for diffuse large B-cell lymphoma (DLBCL). However, there is no consensus on the most appropriate staging system for intestinal DLBCL. We evaluated the utility of the modified Ann Arbor system, the Lugano system, and the Paris staging system (a modification of the Tumor, Node, Metastases [TNM] staging for epithelial tumors) in 66 cases of resected intestinal DLBCL. The cases were treated with surgery, plus either cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) chemotherapy alone (n=26) or with the addition of rituximab immunotherapy (n=40). Median follow-up time was 40.4 months (range, 2.1-171.6 months). Fifty-six patients (84.8%) achieved complete remission. The overall 5-yr survival rate was 86.4% (57/66). Of the stage categories defined for each staging system, only the T stage of the Paris classification showed prognostic significance for overall survival by univariate analysis. However, none of the stage parameters was significantly correlated with patient survival on multivariate analysis. In conclusion, the results suggest that the T stage of the Paris classification system may be a prognostic indicator in intestinal DLBCL. The results also imply that in surgically resected intestinal DLBCL, the addition of rituximab to the CHOP regimen does not confer significant survival advantage. PMID:24431906

Hwang, Hee Sang; Yoon, Dok Hyun; Suh, Cheolwon; Park, Chan-Sik

2014-01-01

221

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)

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.

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

2004-03-01

222

Different Electrostatic Potentials Define ETGE and DLG Motifs as Hinge and Latch in Oxidative Stress Response?  

PubMed Central

Nrf2 is the regulator of the oxidative/electrophilic stress response. Its turnover is maintained by Keap1-mediated proteasomal degradation via a two-site substrate recognition mechanism in which two Nrf2-Keap1 binding sites form a hinge and latch. The E3 ligase adaptor Keap1 recognizes Nrf2 through its conserved ETGE and DLG motifs. In this study, we examined how the ETGE and DLG motifs bind to Keap1 in a very similar fashion but with different binding affinities by comparing the crystal complex of a Keap1-DC domain-DLG peptide with that of a Keap1-DC domain-ETGE peptide. We found that these two motifs interact with the same basic surface of either Keap1-DC domain of the Keap1 homodimer. The DLG motif works to correctly position the lysines within the Nrf2 Neh2 domain for efficient ubiquitination. Together with the results from calorimetric and functional studies, we conclude that different electrostatic potentials primarily define the ETGE and DLG motifs as a hinge and latch that senses the oxidative/electrophilic stress. PMID:17785452

Tong, Kit I.; Padmanabhan, Balasundaram; Kobayashi, Akira; Shang, Chengwei; Hirotsu, Yosuke; Yokoyama, Shigeyuki; Yamamoto, Masayuki

2007-01-01

223

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

NASA Technical Reports Server (NTRS)

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.

Cameron, A. G. W.

1973-01-01

224

Transcriptome Profile at Different Physiological Stages Reveals Potential Mode for Curly Fleece in Chinese Tan Sheep  

PubMed Central

Tan sheep (Ovis aries), a Chinese indigenous breed, has special curly fleece after birth, especially at one month old. However, this unique phenotype disappears gradually with age and the underlying reasons of trait evolvement are still unknown. In this study, skin transcriptome data was used to study this issue. In total 51,215 transcripts including described transcripts and transfrags were identified. Pathway analysis of the top 100 most highly expressed transcripts, which included TCHH and keratin gene family members, such as KRT25, KRT5, KRT71, KRT14 and others, showed pathways known to be relevant to hair/fleece development and function. Six hundred differentially expressed (DE) transcripts were detected at two different physiological ages (one-month-old with curly fleece and 48-month-old without curly fleece) and were categorized into three major functional groups: cellular component, molecular function, and biological process. The top six functional categories included cell, cell part, cellular process, binding, intracellular, metabolic process. The detected differentially expressed genes were particularly involved in signal, signal peptide, disulfide bond, glycoprotein and secreted terms, respectively. Further splicing isoform analysis showed that the metallothionein 3 isoform was up-regulated in Tan lamb skin, indicating that it may be related to the conformation of curly fleece in Chinese Tan lamb. The hair-related important differentially expressed genes (SPINK4, FGF21, ESR?, EphA3, NTNG1 and GPR110) were confirmed by qPCR analysis. We deduced that the differences existed in expressed transcripts, splice isoforms and GO categories between the two different physiological stages, which might constitute the major reasons for explaining the trait evolvement of curly fleece in Chinese Tan sheep. This study provides some clues for elucidating the molecular mechanism of fleece change with age in Chinese Tan sheep, as well as supplying some potential values for understanding human hair disorder and texture changes. PMID:23990983

Liu, Yufang; Xu, Qinqin; Zhang, Ming; Fang, Meiying

2013-01-01

225

Large work function difference driven electron transfer from electrides to single-walled carbon nanotubes  

NASA Astrophysics Data System (ADS)

A difference in work function plays a key role in charge transfer between two materials. Inorganic electrides provide a unique opportunity for electron transfer since interstitial anionic electrons result in a very low work function of 2.4-2.6 eV. Here we investigated charge transfer between two different types of electrides, [Ca2N]+.e- and [Ca24Al28O64]4+.4e-, and single-walled carbon nanotubes (SWNTs) with a work function of 4.73-5.05 eV. [Ca2N]+.e- with open 2-dimensional electron layers was more effective in donating electrons to SWNTs than closed cage structured [Ca24Al28O64]4+.4e- due to the higher electron concentration (1.3 × 1022 cm-3) and mobility (~200 cm2 V-1 s-1 at RT). A non-covalent conjugation enhanced near-infrared fluorescence of SWNTs as high as 52%. The field emission current density of electride-SWNT-silver paste dramatically increased by a factor of 46 000 (14.8 mA cm-2) at 2 V ?m-1 (3.5 wt% [Ca2N]+.e-) with a turn-on voltage of 0.85 V ?m-1.A difference in work function plays a key role in charge transfer between two materials. Inorganic electrides provide a unique opportunity for electron transfer since interstitial anionic electrons result in a very low work function of 2.4-2.6 eV. Here we investigated charge transfer between two different types of electrides, [Ca2N]+.e- and [Ca24Al28O64]4+.4e-, and single-walled carbon nanotubes (SWNTs) with a work function of 4.73-5.05 eV. [Ca2N]+.e- with open 2-dimensional electron layers was more effective in donating electrons to SWNTs than closed cage structured [Ca24Al28O64]4+.4e- due to the higher electron concentration (1.3 × 1022 cm-3) and mobility (~200 cm2 V-1 s-1 at RT). A non-covalent conjugation enhanced near-infrared fluorescence of SWNTs as high as 52%. The field emission current density of electride-SWNT-silver paste dramatically increased by a factor of 46 000 (14.8 mA cm-2) at 2 V ?m-1 (3.5 wt% [Ca2N]+.e-) with a turn-on voltage of 0.85 V ?m-1. Electronic supplementary information (ESI) available: The acronyms of base materials and synthesized specimens, field emission characteristics of PSWNT-Ag paste and HSWNT-Ag paste, additional XPS and Raman data, estimation of transferred electrons from electrides to nanotubes, optical images of C12A7:e--HSWNT films, a SEM image of the tape-activated PSWNT-Ag paste, and comparison of field emission properties. See DOI: 10.1039/c4nr01629g

Menamparambath, Mini Mol; Park, Jong-Ho; Yoo, Ho-Sung; Patole, Shashikant P.; Yoo, Ji-Beom; Kim, Sung Wng; Baik, Seunghyun

2014-07-01

226

Denitrification potential of different land-use types in an agricultural watershed, lower Mississippi valley  

USGS Publications Warehouse

Expansion of agricultural land and excessive nitrogen (N) fertilizer use in the Mississippi River watershed has resulted in a three-fold increase in the nitrate load of the river since the early 1950s. One way to reduce this nitrate load is to restore wetlands at suitable locations between croplands and receiving waters to remove run-off nitrate through denitrification. This research investigated denitrification potential (DP) of different land uses and its controlling factors in an agricultural watershed in the lower Mississippi valley (LMV) to help identify sites with high DP for reducing run-off nitrate. Soil samples collected from seven land-use types of an agricultural watershed during spring, summer, fall and winter were incubated in the laboratory for DP determination. Low-elevation clay soils in wetlands exhibited 6.3 and 2.5 times greater DP compared to high-elevation silt loam and low-elevation clay soils in croplands, respectively. DP of vegetated-ditches was 1.3 and 4.2 times that of un-vegetated ditches and cultivated soils, respectively. Soil carbon and nitrogen availability, bulk density, and soil moisture significantly affected DP. These factors were significantly influenced in turn by landscape position and land-use type of the watershed. It is evident from these results that low-elevation, fine-textured soils under natural wetlands are the best locations for mediating nitrate loss from agricultural watersheds in the LMV. Landscape position and land-use types can be used as indices for the assessment/modeling of denitrification potential and identification of sites for restoration for nitrate removal in agricultural watersheds. ?? 2006 Elsevier B.V. All rights reserved.

Ullah, S.; Faulkner, S. P.

2006-01-01

227

Sediment pollution in the Elbe estuary and its potential toxicity at different trophic levels.  

PubMed

Sediment contamination is one of the most pressing environmental problems in estuaries of industrialized countries and is of special interest to water managers involved in waterway maintenance dredging. In the present study, eight heavy metals (As, Pb, Cd, Cr, Cu, Ni, Hg, and Zn) and 41 organic compounds (pentachlorbenzol (PeCB), hexachlorbenzol (HCB), 7 polychlorinated biphenyls (PCBs), the hexachlorocyclohexanes ?-HCH, ?-HCH, ?-HCH, 6 dichlorodiphenyltrichloroethane isomers, organochlorine styrene (OCS), octachloronaphthalene (OCN), 15 polycyclic aromatic hydrocarbons (PAHs), and 6 organotin (OT) compounds) were analyzed in surface sediments at 36 sites in the Elbe estuary in 2006. Correlation analysis showed a general decrease in sediment contaminant concentrations from the stations near the port of Hamburg towards the open sea. This decrease was significant (Spearman's rank correlation, p<0.05) with most pollutants. In addition, cluster analysis identified five groups of sites with different sediment contaminant patterns within the Elbe estuary. Worst case toxic risks stemming from sediment-bound organic pollutants were predicted using the Toxic Unit approach, based on estimated pore-water concentrations under equilibrium conditions and acute LC50 values for three standard test organisms of the trophic levels of fish, invertebrates, and algae. The estimated sediment toxicity was significantly higher in the inner part (river-km 630 to 660) compared with the estuarine mouth. Moreover, potential toxicity of organic pollutants estimated for invertebrates and for fish exceeded acute-based effect thresholds at 30 and 24 stations, respectively. Chronic effects for invertebrates are expected at all sites investigated. We conclude that sediment pollution and related potential toxicity in the Elbe estuary may have more influence on the benthos fauna than expected to date. PMID:23428749

Wetzel, Markus A; Wahrendorf, Dierk-Steffen; von der Ohe, Peter C

2013-04-01

228

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

NASA Astrophysics Data System (ADS)

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

Nyazov, R.; Nurtaev, B.

2011-12-01

229

Potential Large Animal Models for Gene Therapy of Human Genetic Diseases of Immune and Blood Cell Systems  

PubMed Central

Genetic mutations involving the cellular components of the hematopoietic system—red blood cells, white blood cells, and platelets—manifest clinically as anemia, infection, and bleeding. Although gene targeting has recapitulated many of these diseases in mice, these murine homologues are limited as translational models by their small size and brief life span as well as the fact that mutations induced by gene targeting do not always faithfully reflect the clinical manifestations of such mutations in humans. Many of these limitations can be overcome by identifying large animals with genetic diseases of the hematopoietic system corresponding to their human disease counterparts. In this article, we describe human diseases of the cellular components of the hematopoietic system that have counterparts in large animal species, in most cases carrying mutations in the same gene (CD18 in leukocyte adhesion deficiency) or genes in interacting proteins (DNA cross-link repair 1C protein and protein kinase, DNA-activated, catalytic polypeptide in radiation-sensitive severe combined immunodeficiency). Furthermore, we describe the potential of these animal models to serve as disease-specific, preclinical models for testing the efficacy and safety of clinical interventions such as hematopoietic stem cell transplantation or gene therapy approaches before their use in humans with the corresponding disease. PMID:19293460

Bauer, Thomas R.; Adler, Rima L.; Hickstein, Dennis D.

2009-01-01

230

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

NASA Astrophysics Data System (ADS)

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.

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

231

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

NASA Astrophysics Data System (ADS)

In this study, two parameterizations for different irrigation techniques have been implemented in a regional climate model. These implementations allow for a comparative study of water use and land-atmosphere interactions associated with traditional flood irrigation—a widespread but highly water-inefficient practice—and water-conserving drip irrigation. Both parameterizations yield realistic results for coupled climate simulations, and do so without the need to reproduce an entire crop model within the climate model. Simulations with drip irrigation exhibit ˜30% less irrigation season evapotranspiration and ˜60% less water demand overall relative to simulations with flood irrigation. Examination of the water balance for various irrigation zones in Syria and Turkey demonstrates that planned Syrian irrigation expansion in the Euphrates watershed is only feasible if accompanied by modernization. Even then, planned expansion in the Khabur watershed, a major tributary of the Euphrates, would only reach sustainability if there is significant irrigation water runoff into Syria from Turkey. Thus Syria has a window of opportunity within which it can reap the benefits of investing in modernization and expansion of irrigation. That window begins now, with the Syrian governments recent commitment to modernize its irrigation infrastructure, and in the absence of an international water-sharing agreement, ends when increased water demand and/or decreased precipitation causes the Turkish government to invest in modernizing its own irrigation systems. Such a precipitation decrease is predicted to occur in the Middle East by mid-century if greenhouse gas emissions are not curbed substantially.

Evans, J. P.; Zaitchik, B. F.

2008-08-01

232

Influences of Different Large Mammalian Fauna on Dung Beetle Diversity in Beech Forests  

PubMed Central

This paper focuses on biological relationships between mammalian species richness and the community structure of dung beetles in cool-temperate forests in the northernmost part of mainland Japan. The composition of beetle assemblages was evaluated at 3 sites in undisturbed beech forests with different mammalian fauna. In spring and summer 2009, beetles were collected at each site using pitfall traps baited with feces from Japanese macaques, Macaca fuscata Blyth (Primates: Cercopithecidae); Asiatic black bears, Ursus thibetanus Cuvier (Carnivora: Ursidae); Japanese serows, Capricornis crispus Temminck (Artiodactyla: Bovidae); and cattle. In the present study, 1,862 dung beetles representing 14 species were collected, and most dung beetles possessed the ecological characteristic of selecting specific mammalian feces. The present findings indicated that although species diversity in dung beetle assemblages was not necessarily positively correlated with mammalian species richness in cool-temperate forests, the absence of the macaque population directly resulted in the marked reduction of the beetle abundance, with the loss of the most frequent species, Aphodius eccoptus Bates (Coleoptera: Scarabaeidae) during spring. PMID:23909510

Enari, Hiroto; Koike, Shinsuke; Sakamaki, Haruka

2013-01-01

233

Linkages between microbial functional potential and wastewater constituents in large-scale membrane bioreactors for municipal wastewater treatment.  

PubMed

Large-scale membrane bioreactors (MBRs) have been widely used for the municipal wastewater treatment, whose performance relies on microbial communities of activated sludge. Nevertheless, microbial functional structures in MBRs remain little understood. To gain insight into functional genes and their steering environmental factors, we adopted GeoChip, a high-throughput microarray-based tool, to examine microbial genes in four large-scale, in-operation MBRs located in Beijing, China. The results revealed substantial microbial gene heterogeneity (43.7-85.1% overlaps) among different MBRs. Mantel tests indicated that microbial nutrient cycling genes were significantly (P < 0.05) correlated to influent COD, [Formula: see text] -N, TP or sulfate, which signified the importance of microbial mediation of wastewater constituent removal. In addition, functional genes shared by all four MBRs contained a large number of genes involved in antibiotics resistance, metal resistance and organic remediation, suggesting that they were required for degradation or resistance to toxic compounds in wastewater. The linkages between microbial functional structures and environmental variables were also unveiled by the finding of hydraulic retention time, influent COD, [Formula: see text] -N, mixed liquid temperature and humic substances as major factors shaping microbial communities. Together, the results presented demonstrate the utility of GeoChip-based microarray approach in examining microbial communities of wastewater treatment plants and provide insights into the forces driving important processes of element cycling. PMID:24675272

Sun, Yanmei; Shen, Yue-xiao; Liang, Peng; Zhou, Jizhong; Yang, Yunfeng; Huang, Xia

2014-06-01

234

Sex Differences in ?-Adrenergic Responsiveness of Action Potentials and Intracellular Calcium Handling in Isolated Rabbit Hearts  

PubMed Central

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

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

2014-01-01

235

Large Neurological Component to Genetic Differences Underlying Biased Sperm Use in Drosophila  

PubMed Central

Sperm competition arises as a result of complex interactions among male and female factors. While the roles of some male factors are known, little is known of the molecules or mechanisms that underlie the female contribution to sperm competition. The genetic tools available for Drosophila allow us to identify, in an unbiased manner, candidate female genes that are critical for mediating sperm competition outcomes. We first screened for differences in female sperm storage and use patterns by characterizing the natural variation in sperm competition in a set of 39 lines from the sequenced Drosophila Genetic Reference Panel (DGRP) of wild-derived inbred lines. We found extensive female variation in sperm competition outcomes. To generate a list of candidate female genes for functional studies, we performed a genome-wide association mapping, utilizing the common single-nucleotide polymorphisms (SNPs) segregating in the DGRP lines. Surprisingly, SNPs within ion channel genes and other genes with roles in the nervous system were among the top associated SNPs. Knockdown studies of three candidate genes (para, Rab2, and Rim) in sensory neurons innervating the female reproductive tract indicate that some of these candidate female genes may affect sperm competition by modulating the neural input of these sensory neurons to the female reproductive tract. More extensive functional studies are needed to elucidate the exact role of all these candidate female genes in sperm competition. Nevertheless, the female nervous system appears to have a previously unappreciated role in sperm competition. Our results indicate that the study of female control of sperm competition should not be limited to female reproductive tract-specific genes, but should focus also on diverse biological pathways. PMID:23105014

Chow, Clement Y.; Wolfner, Mariana F.; Clark, Andrew G.

2013-01-01

236

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

PubMed

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

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

2004-09-01

237

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

PubMed Central

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

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

238

Reconstruction of Oomycete Genome Evolution Identifies Differences in Evolutionary Trajectories Leading to Present-Day Large Gene Families  

PubMed Central

The taxonomic class of oomycetes contains numerous pathogens of plants and animals but is related to nonpathogenic diatoms and brown algae. Oomycetes have flexible genomes comprising large gene families that play roles in pathogenicity. The evolutionary processes that shaped the gene content have not yet been studied by applying systematic tree reconciliation of the phylome of these species. We analyzed evolutionary dynamics of ten Stramenopiles. Gene gains, duplications, and losses were inferred by tree reconciliation of 18,459 gene trees constituting the phylome with a highly supported species phylogeny. We reconstructed a strikingly large last common ancestor of the Stramenopiles that contained ?10,000 genes. Throughout evolution, the genomes of pathogenic oomycetes have constantly gained and lost genes, though gene gains through duplications outnumber the losses. The branch leading to the plant pathogenic Phytophthora genus was identified as a major transition point characterized by increased frequency of duplication events that has likely driven the speciation within this genus. Large gene families encoding different classes of enzymes associated with pathogenicity such as glycoside hydrolases are formed by complex and distinct patterns of duplications and losses leading to their expansion in extant oomycetes. This study unveils the large-scale evolutionary dynamics that shaped the genomes of pathogenic oomycetes. By the application of phylogenetic based analyses methods, it provides additional insights that shed light on the complex history of oomycete genome evolution and the emergence of large gene families characteristic for this important class of pathogens. PMID:22230142

Seidl, Michael F.; Van den Ackerveken, Guido; Govers, Francine; Snel, Berend

2012-01-01

239

Genome Sequencing of Listeria monocytogenes "Quargel" Listeriosis Outbreak Strains Reveals Two Different Strains with Distinct In Vitro Virulence Potential  

PubMed Central

A large listeriosis outbreak occurred in Austria, Germany and the Czech Republic in 2009 and 2010. The outbreak was traced back to a traditional Austrian curd cheese called “Quargel” which was contaminated with two distinct serovar 1/2a Listeria monocytogenes strains (QOC1 and QOC2). In this study we sequenced and analysed the genomes of both outbreak strains in order to investigate the extent of genetic diversity between the two strains belonging to MLST sequence types 398 (QOC2) and 403 (QOC1). Both genomes are highly similar, but also display distinct properties: The QOC1 genome is approximately 74 kbp larger than the QOC2 genome. In addition, the strains harbour 93 (QOC1) and 45 (QOC2) genes encoding strain-specific proteins. A 21 kbp region showing highest similarity to plasmid pLMIV encoding three putative internalins is integrated in the QOC1 genome. In contrast to QOC1, strain QOC2 harbours a vip homologue, which encodes a LPXTG surface protein involved in cell invasion. In accordance, in vitro virulence assays revealed distinct differences in invasion efficiency and intracellular proliferation within different cell types. The higher virulence potential of QOC1 in non-phagocytic cells may be explained by the presence of additional internalins in the pLMIV-like region, whereas the higher invasion capability of QOC2 into phagocytic cells may be due to the presence of a vip homologue. In addition, both strains show differences in stress-related gene content. Strain QOC1 encodes a so-called stress survival islet 1, whereas strain QOC2 harbours a homologue of the uncharacterized LMOf2365_0481 gene. Consistently, QOC1 shows higher resistance to acidic, alkaline and gastric stress. In conclusion, our results show that strain QOC1 and QOC2 are distinct and did not recently evolve from a common ancestor. PMID:24587155

Rychli, Kathrin; Muller, Anneliese; Zaiser, Andreas; Schoder, Dagmar; Allerberger, Franz; Wagner, Martin; Schmitz-Esser, Stephan

2014-01-01

240

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

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

Puértolas, Jaime; Alcobendas, Rosalía; Alarcón, Juan J; Dodd, Ian C

2013-08-01

241

Potential Effects of Climate Change on the Water Level, Flora and Macro-fauna of a Large Neotropical Wetland  

PubMed Central

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

Ubeda, Barbara; Di Giacomo, Adrian S.; Neiff, Juan Jose; Loiselle, Steven A.; Guadalupe Poi, Alicia S.; Galvez, Jose Angel; Casco, Silvina; Cozar, Andres

2013-01-01

242

Boy/girl differences in risk for reading disability: potential clues?  

PubMed

The authors conducted a case-control study to determine whether risk factors for reading disability (RD) differentially affect boys and girls. The study population included all children born between 1976 and 1982 in Olmsted County, Minnesota (n = 5,701). A total of 303 RD cases were identified by using intelligence quotient and achievement test scores collected from school and medical records. After excluding those who met exclusion criteria (n = 869), controls consisted of all children not identified with RD (n = 4,529). The authors examined the association between RD and potential risk factors in boys and girls and confirmed their results in multivariable logistic regression models. Multivariable models indicated that girls of low birth weight were more than twice as likely to be identified as RD (odds ratio (OR) = 2.94, 95% confidence interval (CI): 1.09, 6.25). Girls whose mothers had 12 or fewer years of education were twice as likely to be identified as RD (OR = 2.14, 95% CI: 1.24, 3.72). However, girls whose fathers were aged 35 years or older at the time of birth were less likely to be identified as RD (OR = 0.24, 95% CI: 0.06, 0.92). Only 12 or fewer years of paternal education was associated with increased RD in boys (OR = 2.28, 95% CI: 1.59, 3.27). Boys and girls appear to be differentially susceptible to RD risk factors, suggesting that the biologic processes leading to RD may differ between boys and girls. PMID:11682360

St Sauver, J L; Katusic, S K; Barbaresi, W J; Colligan, R C; Jacobsen, S J

2001-11-01

243

Shallow Megathrust Rupture Propagation of Some Large and Giant Earthquakes: Its Tsunami Potential and Identification from Spectral Energy Content  

NASA Astrophysics Data System (ADS)

Rare, slow-rupturing tsunami earthquakes are known to occur in the shallowest megathrust environment that both slows rupture propagation and enhances tsunami potential, while other megathrust earthquakes remain deeper, rupturing more rapidly and having reduced tsunami potential due to diminished vertical seafloor displacement. However, we postulate that the massive transoceanic tsunamis of some giant earthquakes are caused by total megathrust rupture, where coseismic slip extends beyond the normal seismogenic range, and into the near-trench tsunami earthquake environment. Such ruptures drastically enhance seafloor excitation and causing massive tsunami generation. Examples include the 2004 MW 9.1 Sumatran, the 1964 MW 9.2 Alaskan, and the 1960 MW 9.5 Chile earthquakes. For recent events, the spatial extent of rupture into the near-trench is observable through seismologic modeling of fault rupture, and the distribution of early aftershocks. An ideal case-example supporting this hypothesis is the clear change in shallow rupture behavior between the 2004 MW 9.1 and 2005 MW 8.7 Sumatran earthquakes, with the latter reaming deeper and having only modest tsunami excitation. We find that through examination of the rupture energy of recent very large earthquakes we can identify rupture that pervades the shallow trench by the event’s relative deficiency in high-frequency radiated seismic energy, similar to tsunami earthquakes. Testing both bulk spectral energy ratios, and deviations in the high-frequency energy growth during rupture, we identify the Sumatran 2004 event as deficient, while the 2005 Sumatran and 2010 Chile earthquakes appear in the normal range similar to smaller events, identifying them as having normal megathrust ruptures. Unlike finite-fault modeling using seismic waveforms and imaging of early aftershocks, which can also identify near-trench rupture, earthquake energy determinations can be made in near real-time (often within 10 minutes of rupture initiation), making it a useful tool for rapid tsunami hazard assessment.

Newman, A. V.; Convers, J. A.

2010-12-01

244

Observations of Coastal IO Emissions on the Southern Hemisphere and Emission Potential of Different Seaweed Species  

NASA Astrophysics Data System (ADS)

At coastal sites reactive iodine species emitted by seaweed in the intertidal zone during low tide are known to have an important influence on the atmospheric chemistry. However, many underlying mechanisms are presently not understood. Also coastal studies were focused on a few locations on the northern hemisphere and their predominant seaweed species laminaria digitata and ascophyllum nodosum. Therefore the spatial emission and extent of the areas where halogen chemistry is of importance needs to be much better quantified. Especially in the mid latitudes of the southern hemisphere RHS measurements are very sparse. Here we report the first observations of coastal iodine monoxide (IO) in the southern hemisphere during the HALMA/MAORI campaign which was carried out in February to March 2013 on the east coast of New Zealand's South Island at Shag Point located north of Dunedin. To detect IO we used a mobile Open Light Path Cavity Enhanced Differential Optical Absorption Spectroscopy (CE-DOAS) instrument and a stationary Long Path (LP)-DOAS Instrument, which was furthermore used to measure BrO, O3 and I2. The measurement path was positioned over the water and mainly measured air masses that only passes over submerged seaweed forests. With the CE-DOAS placed close to exposed seaweed patches (mainly Macrocystis Pyrifera) we were able to observe high IO mixing ratios of up to 50 ppt (2ppt detection limit). However, the LP-DOAS did not detect IO above the detection limit of 0.7 ppt. This is consistent with previous observations which found that seaweed only emits halogens when exposed to air. To further investigate the emission potential of the seaweed species we setup a Teflon chamber around the CE-DOAS and measured the emissions of five different species for several hours. Additionally the air in the chamber was probed by a compact gas chromatograph (?DIRAC) for measurements of halocarbons and a TEI Ozone monitor. We found very high IO mixing ratios of up to 500 ppt for four seaweed species which correlated with high levels of halocarbons (CH3I, CH2Br2, CH2BrI and CH2BrCl up to 100ppt, CHBr3 up to 600ppt). These results, the similarities and differences in the emission behavior and implications for atmospheric chemistry are discussed.

Horbanski, Martin; Schmitt, Stefan; Frieß, Udo; Pöhler, Denis; Johnston, Paul; Kreher, Karin; Robinson, Andrew D.; Thomas, Alan; Harris, Neil R. P.; Platt, Ulrich

2014-05-01

245

Comparing the rehydration potential of different milk-based drinks to a carbohydrate-electrolyte beverage.  

PubMed

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

Desbrow, Ben; Jansen, Sarah; Barrett, Abby; Leveritt, Michael D; Irwin, Christopher

2014-12-01

246

The Contact Difference of Potential Between Barium and Zinc The External Work Function of Zinc  

Microsoft Academic Search

The methods of contact potential measurement described in previous reports of this series have been extended to zinc, for which the published work function data are discordant. Measurement was by the retarding potential method with variable anode, in tubes sealed from the pumps and gettered with vaporized barium. Barium was the reference metal and the measured surfaces of both barium

Paul A. Anderson

1940-01-01

247

A study of the reproducibility and etiology of diffusion anisotropy differences in developmental stuttering: a potential role for impaired myelination  

PubMed Central

Several diffusion tensor imaging (DTI) studies have reported fractional anisotropy (FA) reductions within the left perisylvian white matter (WM) of persistent developmental stutterers (PSs). However, these studies have not reached the same conclusions in regard to the presence, spatial distribution (focal/ diffuse), and directionality (elevated/reduced) of FA differences outside of the left perisylvian region. In addition, supplemental DTI measures (axial and radial diffusivities, diffusion trace) have yet to be utilized to examine the potential etiology of these FA reductions. Therefore, the present study sought to reexamine earlier findings through a sex- and age-controlled replication analysis and then to extend these findings with the aforementioned non-FA measures. The replication analysis showed that robust FA reductions in PSs were largely focal, left hemispheric, and within late-myelinating associative and commissural fibers (division III of the left superior longitudinal fasciculus, callosal body, forceps minor of the corpus callosum). Additional DTI measures revealed that these FA reductions were attributable to an increase in diffusion perpendicular to the affected fiber tracts (elevated radial diffusivity). These findings suggest a hypothesis that will be testable in future studies: that myelogenesis may be abnormal in PSs within left-hemispheric fiber tracts that begin a prolonged course of myelination in the first postnatal year. PMID:20471482

Cykowski, M.D.; Fox, P.T.; Ingham, R.J.; Ingham, J.C.; Robin, D.A.

2011-01-01

248

Occurrence of large granular lymphocytes and natural killer cells in the epithelium of the gut distinguishes two different coeliac diseases.  

PubMed Central

In a longterm study, we have divided coeliac disease into two distinct entities (abortive and permanent) based on the occurrence of large granular lymphocytes and natural killer cells within the epithelium of the gut. The natural killer and large granular lymphocytes cells were characterised by either immunohistochemical or phase contrast microscopical procedures on the initial biopsies from 15 children with coeliac disease. They were compared with seven individuals with partial villus atrophy and eight with normal villous morphology. Although the histological findings were similar in the initial biopsies of all patients with coeliac disease, the patients with permanent coeliac disease had a significantly lower number (0.41(0.61)cells/mm2) of large granular lymphocytes and natural killer cells compared with those patients with abortive coeliac disease (11.93 (6.23) cells/mm2). Those in the permanent group developed a significantly more pronounced flat mucosa after gluten challenge or provocation compared with the abortive group and had to remain on a strict gluten free diet in contrast with those in the abortive group. Thus, the occurrence of intraepithelial large granular lymphocytes and natural killer cells characterises two distinctly different coeliac diseases. Based on our results neither the histological evaluation of the biopsy nor the utilisation of the revised European Society for Paediatric Gastroenterology and Nutrition (ESPGAN) Criteria are adequate in diagnosing the two types of coeliac disease. Images Figure 1 Figure 2 PMID:1624157

Hadziselimovic, F; Emmons, L R; Schaub, U; Signer, E; Burgin-Wolff, A; Krstic, R

1992-01-01

249

A multi-resolution strategy for a multi-objective deformable image registration framework that accommodates large anatomical differences  

NASA Astrophysics Data System (ADS)

Currently, two major challenges dominate the field of deformable image registration. The first challenge is related to the tuning of the developed methods to specific problems (i.e. how to best combine different objectives such as similarity measure and transformation effort). This is one of the reasons why, despite significant progress, clinical implementation of such techniques has proven to be difficult. The second challenge is to account for large anatomical differences (e.g. large deformations, (dis)appearing structures) that occurred between image acquisitions. In this paper, we study a framework based on multi-objective optimization to improve registration robustness and to simplify tuning for specific applications. Within this framework we specifically consider the use of an advanced model-based evolutionary algorithm for optimization and a dual-dynamic transformation model (i.e. two "non-fixed" grids: one for the source- and one for the target image) to accommodate for large anatomical differences. The framework computes and presents multiple outcomes that represent efficient trade-offs between the different objectives (a so-called Pareto front). In image processing it is common practice, for reasons of robustness and accuracy, to use a multi-resolution strategy. This is, however, only well-established for single-objective registration methods. Here we describe how such a strategy can be realized for our multi-objective approach and compare its results with a single-resolution strategy. For this study we selected the case of prone-supine breast MRI registration. Results show that the well-known advantages of a multi-resolution strategy are successfully transferred to our multi-objective approach, resulting in superior (i.e. Pareto-dominating) outcomes.

Alderliesten, Tanja; Bosman, Peter A. N.; Sonke, Jan-Jakob; Bel, Arjan

2014-03-01

250

Addressing Students' Difficulties in Understanding Two Different Expressions of Gravitational Potential Energy (I): mgh & -GMm/r  

NSDL National Science Digital Library

During our investigation of students' understanding of gravitational potential energy, we found some difficulties that students have with this topic. Many students who took upper-level mechanics courses had difficulties in understanding why there are two different expressions of gravitational potential energy. These students said they had some difficulties in understanding why there should be two different signs (+ & ?) and two different forms (g & 1/r) even though these expressions were considered as representing the same gravitational potential energy. To gain understanding of the sources of student difficulties, we used weekly reports and individual interviews. We analyzed student difficulties in terms of conceptual knowledge, procedural knowledge, and contextual knowledge. The results of these research have guided the development of teaching material that addresses students' difficulties in understanding gravitational potential energy. We will show the development process and contents of the material in the second paper on this topic.

Lee, Gyoungho; Yi, Jinseog

2007-11-25

251

Large pores generated by the combination of different inorganic units in a zinc hydroxide ethynylene diisophthalate MOF.  

PubMed

An ethynylene diisophthalic acid linker molecule was synthesized and used to form a zinc carboxylate-based metal organic framework (MOF) with very large pores and unit cell volume resulting from the unusual combination of structurally different inorganic units forming the secondary building blocks (SBUs). The structure is the first zinc hydroxide carboxylate structure where the inorganic units do not form layers or ribbons but isolated islands. The structure forms true pores with a significantly narrowed pore entry similar to zeolites. The pores are, thus, not created simply by intersecting channels as in most other MOF structures. Although the pore shape is highly asymmetric the spherical free volume is with 10.8 A still large. The stability of the SBUs in respect to exchange and removal of coordinated solvent molecules is investigated. PMID:19322480

Hausdorf, Steffen; Seichter, Wilhelm; Weber, Edwin; Mertens, Florian O R L

2009-02-21

252

Inverse scattering on the line for Schrödinger operators with Miura potentials, II. Different Riccati representatives  

E-print Network

This is the second in a series of papers on scattering theory for one-dimensional Schr\\"odinger operators with Miura potentials admitting a Riccati representation of the form $q=u'+u^2$ for some $u\\in L^2(R)$. We consider potentials for which there exist `left' and `right' Riccati representatives with prescribed integrability on half-lines. This class includes all Faddeev--Marchenko potentials in $L^1(R,(1+|x|)dx)$ generating positive Schr\\"odinger operators as well as many distributional potentials with Dirac delta-functions and Coulomb-like singularities. We completely describe the corresponding set of reflection coefficients $r$ and justify the algorithm reconstructing $q$ from $r$.

R. O. Hryniv; Ya. V. Mykytyuk; P. A. Perry

2009-10-04

253

Cosmic expansion driven by real scalar field for different forms of potential  

NASA Astrophysics Data System (ADS)

We discuss the expansion of the universe in the FRLW model assuming that the source of dark energy is either tachyonic scalar field or quintessence. The tachyonic scalar field with exponential and power-law potential (function of homogeneous scalar field ?) both gives exponential expansion of the universe. It is found that this behaviour is not distinguishable from the quintessence with respect to these potentials.

Verma, Murli Manohar; Pathak, Shankar Dayal

2014-03-01

254

Different ground-state potentials for the same ultracold-collision outcome  

Microsoft Academic Search

For ultracold strontium atoms colliding at 1 ?K, we search for and determine a class of continuous deformations of the ground-state potential curve, under which scattering results are invariant. We search for these potential transformations by keeping track of the changes in the scattering length and photoassociation probabilities (X1?g+?1?u+), as we systematically vary a suitable parametric description of the ground-state

E. M. S. Ribeiro; A. L. M. Zanelatto; R. d. J. Napolitano

2004-01-01

255

Cytoskeletal stiffness, friction, and fluidity of cancer cell lines with different metastatic potential  

PubMed Central

We quantified mechanical properties of cancer cells differing in metastatic potential. These cells included normal and H-ras-transformed NIH3T3 fibroblast cells, normal and oncoprotein-overexpressing MCF10A breast cancer cells, and weakly and strongly metastatic cancer cell line pairs originating from human cancers of the skin (A375P and A375SM cells), kidney (SN12C and SN12PM6 cells), prostate (PC3M and PC3MLN4 cells), and bladder (253J and 253JB5 cells). Using magnetic twisting cytometry, cytoskeletal stiffness (g?) and internal friction (g?) were measured over a wide frequency range. The dependencies of g? and g? upon frequency were used to determine the power law exponent x which is a direct measure of cytoskeletal fluidity and quantifies where the cytoskeleton resides along the spectrum of solid-like (x = 1) to fluid-like (x = 2) states. Cytoskeletal fluidity x increased following transformation by H-ras oncogene expression in NIH3T3 cells, overexpression of ErbB2 and 14-3-3-? in MCF10A cells, and implantation and growth of PC3M and 253J cells in the prostate and bladder, respectively. Each of these perturbations that had previously been shown to enhance cancer cell motility and invasion are shown here to shift the cytoskeleton towards a more fluid-like state. In contrast, strongly metastatic A375SM and SN12PM6 cells that disseminate by lodging in the micro-circulation of peripheral organs had smaller x than did their weakly metastatic cell line pairs A375P and SN12C, respectively. Thus, enhanced hematological dissemination was associated with decreased x and a shift towards a more solid-like cytoskeleton. Taken together, these results are consistent with the notion that adaptations known to enhance metastatic ability in cancer cell lines define a spectrum of fluid-like versus solid-like states, and the position of the cancer cell within this spectrum may be a determinant of cancer progression. PMID:22961212

Coughlin, Mark F.; Bielenberg, Diane R.; Lenormand, Guillaume; Marinkovic, Marina; Waghorne, Carol G.; Zetter, Bruce R.; Fredberg, Jeffrey J.

2013-01-01

256

Tracheal mucus rheology and epithelial potential difference in two day old puppies.  

PubMed

The transepithelial potential difference (PD) value represents an integral of ion fluxes across the epithelium, and relates to the regulation of airway fluid. We studied six healthy two day old husky puppies for their tracheal mucus rheology and bioelectric properties, since this data in newborns are still unknown. PD (-mV, epithelium vs. subcutaneous space) was measured using the agar bridge technique in two locations - lower trachea and subglottic region. For the rheological analysis, the magnetic microrheometer was employed; data are presented as mechanical impedance log G* and loss tangent tan delta (1 rad/s). The mucus collection rate (mg/min) and the solid content (%) were determined by gravimetry. Mucociliary clearability, normalized to frog mucus, (MCFP) was determined directly by the frog palate method; a cough clearability index (CCI) was computed from simulated cough machine data obtained with mucus-like gels. The mucus collection rates and PD values were considerably lower than those observed in adult dogs; the mechanical impedance values were also reduced in comparison with adult data. The PD profile within the trachea (-13.9 +/- 1.2 mV lower trachea vs. -18.4 +/- 1.4 mV subglottical, i.e. more negative subglottically), however, is similar to that observed in adult dogs. Intratracheal profiles in mucus collection rate and mucus rheology were also comparable between puppies and adult dogs. The low collection rates in puppies, particularly in lower trachea, could indicate either reduced mucus volume or slower clearance. PD and collection rate correlated very strongly (r = 0.82, p = 0.0003). PD also correlated negatively with log G* (r = 0.73, p = 0.003) and positively with tan delta (r = 0.58, p = 0.03). MCFP and % solids correlated positively (r = 0.84, p = 0.0012), in contradistinction to the usual relationship, perhaps due to the presence of non-glycoprotein components that do not contribute to crosslink formation. The apparent maturation of airway bioelectric properties, mucus collection rate and mucus viscoelasticity are all consistent with the maturation of mucociliary clearance, which has previously been reported. PMID:2261517

App, E M; King, M

1990-01-01

257

THE CONCENTRATION EFFECT WITH VALONIA: POTENTIAL DIFFERENCES WITH DILUTED POTASSIUM-RICH SEA WATERS  

PubMed Central

The concentration effect with sea waters containing more than the normal amount of potassium has been studied in Valonia macrophysa. This was done by comparing the initial changes in P.D. across the protoplasm when natural sea water bathing the cell was replaced by various isotonic dilutions of KCl-rich sea waters. With small dilutions of KCl-rich sea waters, the P.D.-time curves are of the same form as with the undiluted solution, exhibiting the fluctuations characteristic of KCl-rich solutions. This indicates that with these solutions K+ enters Valonia protoplasm and plays an important part in the P.D. The value of the initial rise in P.D. decreases with increasing dilution. With high dilutions of KCl-rich sea waters, the P.D.-time curves are of quite different shape, resembling the curves with diluted natural sea water; the P.D. is practically independent of small changes in the concentration of potassium, and increases with increasing dilution. That is, with these higher dilutions, the sign of the concentration effect is reversed, becoming the same as with diluted natural sea water. The greater the concentration of KCl in the undiluted sea water, the higher is the critical dilution at which K+ ceases to influence the P.D. For a wide range of sea waters containing both KCl and NaCl, it is shown that the concentration effect above the critical dilution is determined solely by the activity of NaCl in the external solution. It is concluded that with dilute natural sea water and with high dilutions of KCl-rich sea waters we have to do with a diffusion potential, involving only the Na+ and Cl- ions, which are diffusing out from the vacuole. A quantitative relation between the composition of the sea water and the critical dilution has been deduced from the classical theory of the diffusion of electrolytes. It is shown that with dilutions less than this critical value the diffusion of K+ in the outer non-aqueous layer of the protoplasm is directed inward; hence K+ enters the protoplasm from these solutions. With dilutions greater than the critical value, the diffusion of K+ in this layer is directed outward; hence K+ does not enter the protoplasm. Since the P.D. shows no evidence of this outward diffusion of K+, it is concluded that the amount of K+ ordinarily present in the protoplasm is too small to produce any lasting electrical effect, and that the outward diffusion of K+ from the vacuole is prevented by the mechanism responsible for the accumulation of KCl in the cell sap. PMID:19873057

Damon, E. B.

1938-01-01

258

THE CONCENTRATION EFFECT WITH VALONIA: POTENTIAL DIFFERENCES WITH DILUTED POTASSIUM-RICH SEA WATERS.  

PubMed

The concentration effect with sea waters containing more than the normal amount of potassium has been studied in Valonia macrophysa. This was done by comparing the initial changes in P.D. across the protoplasm when natural sea water bathing the cell was replaced by various isotonic dilutions of KCl-rich sea waters. With small dilutions of KCl-rich sea waters, the P.D.-time curves are of the same form as with the undiluted solution, exhibiting the fluctuations characteristic of KCl-rich solutions. This indicates that with these solutions K(+) enters Valonia protoplasm and plays an important part in the P.D. The value of the initial rise in P.D. decreases with increasing dilution. With high dilutions of KCl-rich sea waters, the P.D.-time curves are of quite different shape, resembling the curves with diluted natural sea water; the P.D. is practically independent of small changes in the concentration of potassium, and increases with increasing dilution. That is, with these higher dilutions, the sign of the concentration effect is reversed, becoming the same as with diluted natural sea water. The greater the concentration of KCl in the undiluted sea water, the higher is the critical dilution at which K(+) ceases to influence the P.D. For a wide range of sea waters containing both KCl and NaCl, it is shown that the concentration effect above the critical dilution is determined solely by the activity of NaCl in the external solution. It is concluded that with dilute natural sea water and with high dilutions of KCl-rich sea waters we have to do with a diffusion potential, involving only the Na(+) and Cl(-) ions, which are diffusing out from the vacuole. A quantitative relation between the composition of the sea water and the critical dilution has been deduced from the classical theory of the diffusion of electrolytes. It is shown that with dilutions less than this critical value the diffusion of K(+) in the outer non-aqueous layer of the protoplasm is directed inward; hence K(+) enters the protoplasm from these solutions. With dilutions greater than the critical value, the diffusion of K(+) in this layer is directed outward; hence K(+) does not enter the protoplasm. Since the P.D. shows no evidence of this outward diffusion of K(+), it is concluded that the amount of K(+) ordinarily present in the protoplasm is too small to produce any lasting electrical effect, and that the outward diffusion of K(+) from the vacuole is prevented by the mechanism responsible for the accumulation of KCl in the cell sap. PMID:19873057

Damon, E B

1938-01-20

259

Calculation of free-energy differences and potentials of mean force by a multi-energy gap method  

E-print Network

Calculation of free-energy differences and potentials of mean force by a multi-energy gap method the convergence of free-energy calculations. It introduces a bias factor in Monte Carlo simulations or.e., the difference in energy function between two states, and is therefore specifically designed for calculating free-energy

Weston, Ken

260

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

Microsoft Academic Search

Although 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

Eric Pakulak; Helen J. Neville

2010-01-01

261

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

PubMed Central

Lithodid crabs (and other skeleton-crushing predators) may have been excluded from cold Antarctic continental shelf waters for more than 14 Myr. The west Antarctic Peninsula shelf is warming rapidly and has been hypothesized to be soon invaded by lithodids. A remotely operated vehicle survey in Palmer Deep, a basin 120 km onto the Antarctic shelf, revealed a large, reproductive population of lithodids, providing the first evidence that king crabs have crossed the Antarctic shelf. DNA sequencing and morphology indicate the lithodid is Neolithodes yaldwyni Ahyong & Dawson, previously reported only from Ross Sea waters. We estimate a N. yaldwyni population density of 10 600 km?2 and a population size of 1.55 × 106 in Palmer Deep, a density similar to lithodid populations of commercial interest around Alaska and South Georgia. The lithodid occurred at depths of more than 850 m and temperatures of more than 1.4°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

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

2012-01-01

262

Estimating the potential impacts of large mesopredators on benthic resources: integrative assessment of spotted eagle ray foraging ecology in Bermuda.  

PubMed

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

Ajemian, Matthew J; Powers, Sean P; Murdoch, Thaddeus J T

2012-01-01

263

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

PubMed

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

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

2012-03-01

264

Estimating the Potential Impacts of Large Mesopredators on Benthic Resources: Integrative Assessment of Spotted Eagle Ray Foraging Ecology in Bermuda  

PubMed Central

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

Ajemian, Matthew J.; Powers, Sean P.; Murdoch, Thaddeus J. T.

2012-01-01

265

A large survey of Croatian wild mammals for Giardia duodenalis reveals a low prevalence and limited zoonotic potential.  

PubMed

Wild mammals are considered an important source of potentially zoonotic Giardia duodenalis parasites, yet surprisingly little information is available on the actual prevalence and the genetic identity of the species they harbor. A large survey was conducted in Croatia by collecting 832 fecal samples from red deer (Cervus elaphus, n = 374), roe deer (Capreolus capreolus, n = 21), wild boars (Sus scrofa, n = 144), foxes (Vulpes vulpes, n = 66), bears (Ursus arctos, n = 19), wolves (Canis lupus, n = 127), jackals (Canis aureus, n = 8), and hares (Lepus europeus, n = 73). Fecal samples were tested for the presence of Giardia cysts using fluorescent microscopy. The observed prevalence ranged from low (1% in red deer, 1.7% in wild boars, and 4.5% in foxes) to moderate (10% in wolves and 12.5% in jackals) to high (24% in roe deer). No cysts were observed in bears and hares. Polymerase chain reaction was performed on microscopically positive samples to amplify fragments of the small subunit ribosomal gene, the ribosomal 5.8S gene and the two flanking internal transcribed sequences, and the triose phosphate isomerase gene. Sequence analysis showed a predominance of G. duodenalis assemblage A in both ruminants (genotypes A1 and A3) and carnivores (genotype A1). G. duodenalis assemblages B, C, and D, as well as Giardia microti, were also detected in this study. This is the first molecular description of the parasite from the red deer, the wolf, and the jackal. The data point to a minor role of wild mammals as reservoirs of zoonotic assemblages of G. duodenalis, albeit cycling between sylvatic and domestic animals is possible. PMID:21142957

Beck, Relja; Sprong, Hein; Lucinger, Snjezana; Pozio, Edoardo; Cacciò, Simone M

2011-08-01

266

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

SciTech Connect

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.

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

1989-12-01

267

Large magnetic storms as viewed by TWINS: A study of the differences in the medium energy ENA composition  

NASA Astrophysics Data System (ADS)

large geomagnetic storms (Dst ?-100 nT), oxygen can become a significant component of the energetic particles of the inner magnetosphere. Until recently, there were no available global observations of the medium energy (<50 keV) oxygen populations. Using observations from the Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) Energetic Neutral Atom (ENA) imagers we present a study of nine large storms of solar cycle 24 as a function of storm phase. For these storms we observe that the H and O ENA fluxes and their temperatures increase in tandem during the storm's initial phase. However, there is no increase in the O+/H+ ratio in the inner magnetosphere until the storm main phase. Also seen during the main phase is an energy dispersion with higher-energy (32 keV) H ENAs seen before the arrival of O ENAs of the same energy. The O ENAs take longer to return to prestorm levels during the recovery phases. This longer recovery time is likely because of the large difference between the storm time and prestorm O populations compared to H (i.e., there is always some prestorm H in the inner magnetosphere, but effectively no O prestorm). These results imply that medium-energy O ENAs evolve over long time scales (hours to days) as opposed to the shorter substorm time scales of the higher-energy (>52 keV) O ENAs.

Valek, P. W.; Goldstein, J.; McComas, D. J.; Fok, M.-C.; Mitchell, D. G.

2014-04-01

268

Investigation on the Plasma-Induced Emission Properties of Large Area Carbon Nanotube Array Cathodes with Different Morphologies  

PubMed Central

Large area well-aligned carbon nanotube (CNT) arrays with different morphologies were synthesized by using a chemical vapor deposition. The plasma-induced emission properties of CNT array cathodes with different morphologies were investigated. The ratio of CNT height to CNT-to-CNT distance has considerable effects on their plasma-induced emission properties. As the ratio increases, emission currents of CNT array cathodes decrease due to screening effects. Under the pulse electric field of about 6 V/?m, high-intensity electron beams of 170–180 A/cm2 were emitted from the surface plasma. The production mechanism of the high-intensity electron beams emitted from the CNT arrays was plasma-induced emission. Moreover, the distribution of the electron beams was in situ characterized by the light emission from the surface plasma.

2011-01-01

269

The effective group potential, a new method for the study of spectrum in large molecules: Tests and perspectives  

Microsoft Academic Search

The new method, called effective group potential, which generalizes the concept of effective core potential by including in a potential the effects of many atoms ligand, is used to calculate transition energies. Three molecules containing a metal atom (Cu, Cr, Ni) surrounded by NH3 ligands have been studied. It is shown that by replacing the NH3 group by an effective

Jean-Louis Heully; Romuald Poteau; Sandra Berasaluce; Fabienne Alary

2002-01-01

270

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

PubMed

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

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

2014-01-01

271

The potential and force law between different-size bubbles in soap bubble rafts  

Microsoft Academic Search

Since the Bragg bubble model continues to be a powerful tool for modelling interatomic binding and inelastic processes in close-packed metals with particularly attractive applications to the mechanism of plastic flow in metallic glasses, the inter-bubble potential previously developed by Nicolson and Lomer has been generalized to cover interactions between bubbles of unequal size. Fitting the binding energy between pairs

L. T. Shi; A. S. Argon

1982-01-01

272

Opposite role of changes in mitochondrial membrane potential in different apoptotic processes  

Microsoft Academic Search

We have studied the role of changes in mitochondrial membrane potential (??) in two widely-used models of apoptosis, such as dexamethasone-treated rat thymocytes and U937 human cells treated with tumor necrosis factor-? and cycloheximide. To dissipate ??, we used low concentrations of valinomycin, unable per se to induce apoptosis, and demonstrated that the decline in ?? exerts opposite effects in

Stefano Salvioli; Cristiana Barbi; Jurek Dobrucki; Laura Moretti; Marcello Pinti; Jessica Pedrazzi; Teresa Loredana Pazienza; Valentina Bobyleva; Claudio Franceschi; Andrea Cossarizza

2000-01-01

273

Pattern electroretinogram and visual evoked potential amplitudes are influenced by different stimulus field sizes and scotomata  

Microsoft Academic Search

The pattern electroretinogram and the visual evoked potential were recorded simultaneously with various stimulus fields and artificial scotomata of increasing sizes. In contrast to an earlier study, a smaller check size (20') and two stimulus field sizes (20° × 20° and 10° × 10°) for the scotomata were used. With a concentric decreasing stimulus field, a reduction of both the

Armin Junghardt; Hannes Wildberger; Yves Robert; Bela Török

1993-01-01

274

Integrating Differences: Design Culture's Potential Impact on Contemporary Education  

ERIC Educational Resources Information Center

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,…

Uri, Therese

2012-01-01

275

Sex-related differences in the hemispheric laterality of slow cortical potentials during the preparation of visually guided movements  

Microsoft Academic Search

Previous work suggests the presence of sex differences in the laterality of brain activity in the premotor–parietal network\\u000a during the preparation of visually guided reaching movements. In the current study, electroencephalography was used to test\\u000a the hypothesis that women would have higher amplitude potentials over frontal and parietal regions ipsilateral to arm movements,\\u000a relative to men. Event-related slow cortical potentials

Diana Judith Gorbet; Laura B. Mader; W. Richard Staines

2010-01-01

276

Establishment of cell clones with different metastatic potential from the metastatic hepatocellular carcinoma cell line MHCC97  

Microsoft Academic Search

AIM To establish clone cells with different metastatic potential for the study of metastasis-related mechanisms. METHODS Cloning procedure was performed on parental hepatocellular carcinoma (HCC) cell line MHCC97, and biological characteristics of the target clones selected by in vivo screening were studied. RESULTS Two clones with high (MHCC97-H) and low (MHCC97-L) metastatic potential were isolated from the parent cell line.

Yan Li; Zhao-You Tang; Sheng-Long Ye; Yin-Kun Liu; Jie Chen; Qiong Xue; Jun Chen; Dong-Mei Gao; Wei-Hua Bao

2001-01-01

277

Ecstasy and methamphetamine elicit action potential bursts via different mechanisms in a central snail neuron.  

PubMed

This study sought to determine the effects of (+) methamphetamine (METH) and its ring-substituted analog (+/-)3,4-methylenedioxymethamphetamine (MDMA; ecstasy) on electrophysiological behavior and their relationships to second messenger systems in an identifiable RP4 neuron of the African snail, Achatina fulica Ferussac. Extracellular application of MDMA at 1mM and METH at 3mM elicited action potential bursts that were not blocked after immersing the neurons in Ca(2+)-free solution. Notably, MDMA- (1mM) elicited action potential bursts were blocked by pretreatment with the protein kinase C (PKC) inhibitors chelerythrine (20 microM) and Ro 31-8220 (20 microM), but not by the PKA inhibitors KT-5720 (10 microM) and H89 (10 microM). The PKC activator phorbol 12,13-dibutyrate (PDBu; 3 microM), but not the PKA activator forskolin (50 microM), facilitated the induction of bursts elicited by MDMA at a lower concentration (0.3mM). In contrast, METH- (3mM) elicited action potential bursts were blocked by pretreatment with KT-5720 (10 microM) and H89 (10 microM), but not by chelerythrine (20 microM) and Ro 31-8220 (20 microM). Forskolin (50 microM), but not PDBu (3 microM) facilitated the induction of bursts elicited by METH at a lower concentration (1mM). Tetraethylammonium chloride (TEA), a blocker of the delayed rectifying K(+) current (I(KD)), did not elicit bursts at a concentration of 5mM but did facilitate the induction of action potential bursts elicited by both METH and MDMA. Voltage clamp studies revealed that both METH and MDMA decreased the TEA-sensitive I(KD) of the RP4 neuron. Forskolin (50 microM) or dibutyryl cAMP (1mM), a membrane-permeable cAMP analog, alone did not elicit action potential bursts. However, co-administration with forskolin (50 microM) and TEA (5mM) or co-administration with dibutyryl cAMP (1mM) and TEA (50mM) elicited action potential bursts in the presence of the PKC inhibitor chelerythrine (20 microM). Similarly, PDBu (10 microM) or phorbol 12-myristate 13-acetate (PMA; 3 microM) alone did not elicit action potential bursts. However, co-administration with PDBu (10 microM) and TEA (5mM) or co-administration with PMA (3 microM) and TEA (5mM) elicited action potential bursts in the presence of the PKA inhibitor KT-5720 (10 microM). These data suggest that action potential bursts in the RP4 neuron were not due to Ca(2+)-dependent synaptic effects. Rather, action potential bursts may be elicited through (1) combined activation of the cAMP-PKA signaling pathway and inhibition of the I(KD) and (2) combined activation of PKC and inhibition of the I(KD). PMID:19958791

Lin, Pei-Lin; Tsai, Ming-Cheng; Lu, Guan-Ling; Lu, Dah-Yuu; Chuang, Chieh-Min; Yang, Han-Yin; Huang, Shiang-Suo; Chen, Yi-Hung

2010-01-01

278

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

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

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

2014-01-01

279

Evaluation of the Potential Environmental Impacts from Large-Scale Use and Production of Hydrogen in Energy and Transportation Applications  

SciTech Connect

The purpose of this project is to systematically identify and examine possible near and long-term ecological and environmental effects from the production of hydrogen from various energy sources based on the DOE hydrogen production strategy and the use of that hydrogen in transportation applications. This project uses state-of-the-art numerical modeling tools of the environment and energy system emissions in combination with relevant new and prior measurements and other analyses to assess the understanding of the potential ecological and environmental impacts from hydrogen market penetration. H2 technology options and market penetration scenarios will be evaluated using energy-technology-economics models as well as atmospheric trace gas projections based on the IPCC SRES scenarios including the decline in halocarbons due to the Montreal Protocol. Specifically we investigate the impact of hydrogen releases on the oxidative capacity of the atmosphere, the long-term stability of the ozone layer due to changes in hydrogen emissions, the impact of hydrogen emissions and resulting concentrations on climate, the impact on microbial ecosystems involved in hydrogen uptake, and criteria pollutants emitted from distributed and centralized hydrogen production pathways and their impacts on human health, air quality, ecosystems, and structures under different penetration scenarios

Wuebbles, D.J.; Dubey, M.K., Edmonds, J.; Layzell, D.; Olsen, S.; Rahn, T.; Rocket, A.; Wang, D.; Jia, W.

2010-06-01

280

Proficiency Differences in Syntactic Processing of Monolingual Native Speakers Indexed by Event-Related Potentials  

ERIC Educational Resources Information Center

Although 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…

Pakulak, Eric; Neville, Helen J.

2010-01-01

281

Genetic differences in the antinociceptive effect of morphine and its potentiation by dextromethorphan in rats  

Microsoft Academic Search

The effect of the non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist dextromethorphan on morphine-induced antinociception was studied with the hot plate test in Sprague–Dawley (SD), Wistar–Kyoto (WK), Spontaneously Hypertensive (SHR) and Dark-Agouti (DA) rats. Subcutaneous morphine at 5 mg\\/kg induced significant antinociception in all four rats strains. Subcutaneous dextromethorphan at 15 and 45 mg\\/kg, but not 5 mg\\/kg, significantly and dose-dependently potentiated

Aida Plesan; Orsolya Hoffmann; Xiao-Jun Xu; Zsuzsanna Wiesenfeld-Hallin

1999-01-01

282

Multiparametric analysis of cells with different mitochondrial membrane potential during apoptosis by polychromatic flow cytometry  

Microsoft Academic Search

The analysis of changes in mitochondrial membrane potential (MMP) that can occur during apoptosis provides precious information on the mechanisms and pathways of cell death. For many years, the metachromatic fluorochrome JC-1 (5,5?,6,6?-tetrachloro-1,1?,3,3?-tetraethylbenzimidazolcarbocyanine iodide) was used for this purpose. Thanks to new dyes and to the technical improvements recently adopted in several flow cytometers, it is now possible to investigate,

Leonarda Troiano; Roberta Ferraresi; Enrico Lugli; Elisa Nemes; Erika Roat; Milena Nasi; Marcello Pinti; Andrea Cossarizza

2007-01-01

283

Nitrogen mineralization potentials of shrub-steppe soils with different disturbance histories  

Microsoft Academic Search

Disturbance of shrub-steppe soils and changes in the dominant plant cover may alter soil N-cycling processes. The mineralization of organic N to plant-available forms is an important component of the N cycle in shrub-steppe soils. Therefore, the soil N-mineralization potential (N{sub o}) was determined for two arid ecosystems, an undisturbed perennial shrub-steppe and an annual grassland, which was initially shrub-steppe

H. Jr. Bolton; R. E. Wildung; J. L. Smith

2009-01-01

284

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

E-print Network

Air Quality and Climate[C]. Beijing, China, 2005.9 :1079-1084 [2] C Huang, S Liu. Discussion on the Design and Use of a Hybrid System. The Yellow Sea International Exchange Meeting on Building Environment and Energy[C]. Fukuoka Japan, 2006.1 [3... Air Quality and Climate[C]. Beijing, China, 2005.9 :1079-1084 [2] C Huang, S Liu. Discussion on the Design and Use of a Hybrid System. The Yellow Sea International Exchange Meeting on Building Environment and Energy[C]. Fukuoka Japan, 2006.1 [3...

Liu, S.; Huang, C.

2006-01-01

285

A large Bradbury Nielsen ion gate with flexible wire spacing based on photo-etched stainless steel grids and its characterization applying symmetric and asymmetric potentials  

E-print Network

Bradbury Nielsen gates are well known devices used to switch ion beams and are typically applied in mass or mobility spectrometers for separating beam constituents by their different flight or drift times. A Bradbury Nielsen gate consists of two interleaved sets of electrodes. If two voltages of the same amplitude but opposite polarity are applied the gate is closed, and for identical (zero) potential the gate is open. Whereas former realizations of the device employ actual wires resulting in difficulties with winding, fixing and tensioning them, our approach is to use two grids photo-etched from a metallic foil. This design allows for simplified construction of gates covering large beam sizes up to at least 900\\,mm$^2$ with variable wire spacing down to 250\\,\\textmu m. By changing the grids the wire spacing can be varied easily. A gate of this design was installed and systematically tested at TRIUMF's ion trap facility, TITAN, for use with radioactive beams to separate ions with different mass-to-charge ratios by their time-of-flight.

T. Brunner; A. R. Mueller; K. O'Sullivan; M. C. Simon; M. Kossick; S. Ettenauer; A. T. Gallant; E. Mané; D. Bishop; M. Good; G. Gratta; J. Dilling

2011-07-20

286

Regional Differences in Corn Ethanol Production: Profitability and Potential Water Demands  

E-print Network

to location differences. Changes in consumptive water use in the Texas High Plains, Southern Minnesota, and the Central Valley of California, as impacted by current and proposed grain-based ethanol plants were addressed. In addition, this research assesses...

Higgins, Lindsey M.

2010-07-14

287

The characteristics of the nematode faunas in subtidal sediments of a large microtidal estuary and nearshore coastal waters differ markedly  

NASA Astrophysics Data System (ADS)

The present study examines traditional paradigms regarding the differences between faunas in estuaries vs coastal waters. The ecological characteristics of the free-living nematode faunas of nearshore, subtidal sediments in downstream and upstream areas of the large, microtidal Swan River Estuary are compared with those similarly recorded seasonally in subtidal sediments along an adjacent part of the coast of temperate south-western Australia. Overall, the nematode species richness recorded in the upstream (38) and downstream estuarine areas (58) and from throughout the estuary (61) were substantially less than in marine waters (75). In addition, the value for Simpson's diversity index was marginally less in the estuary and the dominance of the most abundant species greater. In contrast, the mean nematode species richness and diversity in individual cores followed the reverse trend, reflecting a combination of less variability among the species compositions and far greater densities in the cores from estuarine sediments. Furthermore, the mean density (numbers 10 cm -2) was far higher in both upstream (341) and downstream (903) areas of the estuary than in marine waters (87). Although the compositions of the assemblages in upstream and downstream estuarine areas differed markedly from each other at the species, genus and family levels, these differences were less pronounced than those between either of these areas and marine waters. The trophic compositions at the moderately sheltered and fully exposed marine sites differed from that in both areas of the estuary, whereas that at the most sheltered marine site was similar to that in the downstream estuarine area, with both containing substantial proportions of epistrate-grazing species. The variations among the species richness, diversity, densities and taxonomic and trophic compositions of nematode assemblages in the sediments of the two estuarine areas and nearby marine waters appear to reflect differences in 1) salinity regimes, 2) extents of exposure to wave action and its related effects and 3) amounts and types of food available to nematodes.

Hourston, M.; Potter, I. C.; Warwick, R. M.; Valesini, F. J.

2011-07-01

288

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

PubMed Central

We provide theoretical predictions of the intrinsic stability of different arrangements of guanine quadruplex (G-DNA) stems. Most computational studies of nucleic acids have applied Molecular Mechanics (MM) approaches using simple pairwise-additive force fields. The principle limitation of such calculations is the highly approximate nature of the force fields. In this study we for the first time apply accurate QM computations (DFT-D3 with large atomic orbital basis sets) to essentially complete DNA building blocks, namely, seven different folds of the cation-stabilized 2-quartet G-DNA stem, each having more than 250 atoms. The solvent effects are approximated by COSMO continuum solvent. We reveal sizeable differences between MM and QM descriptions of relative energies of different G-DNA stems, which apparently reflect approximations of the DNA force field. Using the QM energy data, we propose correction to earlier free energy estimates of relative stabilities of different parallel, hybrid and antiparallel G-stem folds based on classical simulations. The new energy ranking visibly improves the agreement between theory and experiment. We predict the 5?-anti-anti-3? GpG dinucleotide step to be the most stable one, closely followed by the 5?-syn-anti-3? step. The results are in good agreement with known experimental structures of 2, 3 and 4-quartet G-DNA stems. Besides providing specific results for G-DNA, our study highlights basic limitations of force field modeling of nucleic acids. Although QM computations have their own limitations, mainly the lack of conformational sampling and the approximate description of the solvent, they can substantially improve quality of calculations currently relying exclusively on force fields. PMID:23742743

Sponer, Jiri; Mladek, Arnost; Spackova, Nad'a; Cang, Xiaohui; Cheatham, Thomas E.; Grimme, Stefan

2013-01-01

289

Fog Forecasting using Synergy between Models of different Complexity: Large-Eddy Simulation, Column modelling and Limited Area Modelling  

NASA Astrophysics Data System (ADS)

Fog is a hazardous weather phenomenon with a large impact on the environment and human life. In particular the transportation sector is vulnerable to fog; but fog is also important for agriculture, for leaf-wetness duration in particular, and for humans with asthma or related diseases. In addition, fog and low level clouds govern to a large extent the radiation balance of the polar regions in summer, and as such fog also influences the regional climate. Hence a thorough understanding of the fog governing processes is essential. However, due to the complexity and small scale nature of the relevant physical processes, the current understanding is relatively poor, as is our ability to forecast fog. In order to improve our knowledge, and to identify key deficiencies in the current state of the art fog forecasting models, we present an experiment in which the synergy between models of different complexity and observations is used to evaluate model skill. Therefore, an observed case study (Cabauw; The Netherlands) of a well developed radiation fog will be innovatively run with a large eddy simulation model which allows us to evaluate the key issue of turbulent mixing. In addition, operational and research column models (PAFOG; Duynkerke, 1991) will be employed to evaluate their skill on the local scale, while at the limited area models WRF-NMMFOG (Mueller et al 2010) and COSMO-FOG will be evaluated on their skill for the regional scale. Special focus will be given to the representation of the boundary-layer vertical structure and turbulence in the latter two model types versus the LES results with its solid physical ground.

Steeneveld, G. J.; Masbou, M.; van Heerwaarden, C. C.; Mohr, C.; Schneider, W.; Müller, M.; Bott, A.; Holtslag, A. A. M.

2010-07-01

290

Large-scale analysis of changing frequencies of rain-on-snow events with flood-generation potential  

NASA Astrophysics Data System (ADS)

In January 2011 a rain-on-snow (RoS) event caused floods in the major river basins in central Europe, i.e. the Rhine, Danube, Weser, Elbe, Oder, and Ems. This event prompted the questions of how to define a RoS event and whether those events have become more frequent. Based on the flood of January 2011 and on other known events of the past, threshold values for potentially flood-generating RoS events were determined. Consequently events with rainfall of at least 3 mm on a snowpack of at least 10 mm snow water equivalent (SWE) and for which the sum of rainfall and snowmelt contains a minimum of 20% snowmelt were analysed. RoS events were estimated for the time period 1950-2011 and for the entire study area based on a temperature index snow model driven with a European-scale gridded data set of daily climate (E-OBS data). Frequencies and magnitudes of the modelled events differ depending on the elevation range. When distinguishing alpine, upland, and lowland basins, we found that upland basins are most influenced by RoS events. Overall, the frequency of rainfall increased during winter, while the frequency of snowfall decreased during spring. A decrease in the frequency of RoS events from April to May has been observed in all upland basins since 1990. In contrast, the results suggest an increasing trend in the magnitude and frequency of RoS days in January and February for most of the lowland and upland basins. These results suggest that the flood hazard from RoS events in the early winter season has increased in the medium-elevation mountain ranges of central Europe, especially in the Rhine, Weser, and Elbe river basins.

Freudiger, D.; Kohn, I.; Stahl, K.; Weiler, M.

2014-07-01

291

[Leaf water potential of spring wheat and field pea under different tillage patterns and its relationships with environmental factors].  

PubMed

Based on a long-term experiment, the leaf water potential of spring wheat and field pea, its relationships with environmental factors, and the diurnal variations of leaf relative water content and water saturation deficient under different tillage patterns were studied. The results showed that during whole growth period, field pea had an obviously higher leaf water potential than spring wheat, but the two crops had similar diurnal variation trend of their leaf water potential, i.e., the highest in early morning, followed by a descent, and a gradual ascent after the descent. For spring wheat, the maximum leaf water potential appeared at its jointing and heading stages, followed by at booting and flowering stages, and the minimum appeared at filling stage. For field pea, the maximum leaf water potential achieved at squaring stage, followed by at branching and flowering stages, and the minimum was at podding stage. The leaf relative water content of spring wheat was the highest at heading stage, followed by at jointing and flowering stages, and achieved the minimum at filling stage; while the water saturation deficient was just in adverse. With the growth of field pea, its leaf relative water content decreased, but leaf water saturation deficient increased. The leaf water potential of both spring wheat and field pea had significant correlations with environmental factors, including soil water content, air temperature, solar radiation, relative air humidity, and air water potential. Path analysis showed that the meteorological factor which had the strongest effect on the diurnal variation of spring wheat' s and field pea' s leaf water potential was air water potential and air temperature, respectively. Compared with conventional tillage, the protective tillage patterns no-till, no-till plus straw mulching, and conventional tillage plus straw returning increased the leaf water potential and relative water content of test crops, and the effect of no-till plus straw mulching was most significant. PMID:18839905

Zhang, Ming; Zhang, Ren-Zhi; Cai, Li-Qun

2008-07-01

292

Identification of conserved potentially regulatory sequences of the SRY gene from 10 different species of mammals.  

PubMed

We have sequenced the 5' region of the SRY gene from human, chimpanzee, sheep, and mouse and from four additional mammalian species, not previously characterized (gorilla, gazelle, rat, and guinea pig). In order to identify conserved DNA elements potentially involved in the regulation of the SRY gene, the newly determined sequences were analyzed and compared to all mammalian SRY promoter sequences available at present. Ten highly conserved potential regulatory elements have been identified in all 10 species (AP1, Barbie, GATA, Gfi1, cMyb, vMyb, NF1, Oct1, Sp1, and SRY). The known function of several of these regulatory elements fits well with the known expression of the SRY gene. However, except for the highly conserved coding HMG motif, only a short region close to the initiation of transcription in the human SRY is conserved in the exact position along the gene in all the species analyzed. This lack of sequence identity at the orthologous positions is consistent with the suggested rapid evolution of the SRY gene. This relative lack of homology contrasts with a high sequence identity of the putative regulatory sequences found within each taxonomic group of species (primates, bovids, and rodents), which supports a common mechanism of SRY expression and possibly also a similar function. PMID:9571157

Margarit, E; Guillén, A; Rebordosa, C; Vidal-Taboada, J; Sánchez, M; Ballesta, F; Oliva, R

1998-04-17

293

[Comparative hygienic assessment of potential risk to workers under application of fungicides of different classes].  

PubMed

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

Vavrinevych, O P; Omel'chuk, S T; Bardov, V H

2014-01-01

294

A hybrid potential theory for predicting the motions of a moored ship induced by large-scaled tsunami  

Microsoft Academic Search

In our previous study, we proposed a practical numerical simulation method on moored ship motions induced by tsunami, which was attained by a connection between a tsunami profile by the tsunami simulation and a velocity potential around the ship. The velocity potential was derived from the tsunami profile, which was able to express and calculate not only the surface elevation

Shigeki Sakakibara; Shoji Takeda; Yuji Iwamoto; Masayoshi Kubo

2010-01-01

295

Interaction of hydro- or lipophilic phthalocyanines with cells of different metastatic potential.  

PubMed

A highly metastatic (4R) and a nonmetastatic (RE4) transformed rat embryo fibroblast cell line were incubated with lipid-soluble Zn(II)-phthalocyanine (ZnPc) and its water-soluble tetrasulphonated derivative (ZnPcTS) and compared for phthalocyanine uptake. The hydrophobic liposome-delivered ZnPc showed a significantly greater uptake by both cell lines than did ZnPcTS. Moreover, the two phthalocyanines appear to interact with cells according to different pathways, as suggested by the different temperature-dependence of the binding process and the different inhibitory action exerted by selected serum proteins, such as lipoproteins and heavy proteins. Under all experimental conditions, the two cell lines exhibited similar interactions with ZnPc and ZnPcTS, suggesting that heterogeneity of the tumor cell population has a minor influence on the accumulation of photosensitizers. PMID:8615893

Valduga, G; Bianco, G; Csik, G; Reddi, E; Masiero, L; Garbisa, S; Jori, G

1996-03-01

296

Individual Differences in Nonverbal Number Discrimination Correlate with Event-Related Potentials and Measures of Probabilistic Reasoning  

ERIC Educational Resources Information Center

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…

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

2010-01-01

297

Variations in Oil Potential and Chemical Composition of Eucalyptus crebra Among Different Districts of Punjab-Pakistan  

Microsoft Academic Search

The present research work was aimed to study the intraprovenance variation for content and chemical composition of essential oil obtained from leaves of Eucalyptus crebra. For this purpose, leave samples of mature Eucalyptus crebra plants were collected from different districts of Punjab and oil was extracted and purified after pretreatment. Oil potential was calculated and samples were characterized for their

HAQ NAWAZ BHATTI; ZAFAR IQBAL; SHAHZAD ALI; SHAHID CHATHA; IFTIKHAR HUSSAIN BUKHARI

298

Electrical potential difference and absorption of water, sodium, and potassium by the terminal ileum of ileostomy patients  

Microsoft Academic Search

Measurements of electrical potential difference (pd) and of absorption by a dialysis method were carried out in the terminal ileum of patients with an ileostomy. The pd measured with saline in the lumen and at a few centimetres within the stoma averaged 9.2 mV, lumen negatively charged. The pd values were similar whether the ileostomy had been recently or long

J. Prado P. De Moraes-Filho; C. Salas-Coll; Laurie Blendis; C. J. Edmonds

1974-01-01

299

The electrical potential difference across cracks in PZT measured by Kelvin Probe Microscopy and the implications for fracture  

Microsoft Academic Search

An indentation crack in a poled PZT ceramic subjected to an electric field is investigated using AFM and KFM to determine the crack opening displacement and the electrical potential difference across the crack. The experimental results are used to calculate the crack tip stress and dielectric displacement intensity factors and the crack tip energy release rate. From the applied electric

G. A. Schneider; F. Felten; R. M. McMeeking

2003-01-01

300

Structural Rationalization of a Large Difference in RNA Affinity Despite a Small Difference in Chemistry between Two 2'-O-Modified Nucleic Acid Analogs  

SciTech Connect

Chemical modification of nucleic acids at the 2'-position of ribose has generated antisense oligonucleotides (AONs) with a range of desirable properties. Electron-withdrawing substituents such as 2'-O-[2-(methoxy)ethyl] (MOE) confer enhanced RNA affinity relative to that of DNA by conformationally preorganizing an AON for pairing with the RNA target and by improving backbone hydration. 2'-Substitution of the ribose has also been shown to increase nuclease resistance and cellular uptake via changes in lipophilicity. Interestingly, incorporation of either 2'-O-[2-(methylamino)-2-oxoethyl]- (NMA) or 2'-O-(N-methylcarbamate)-modified (NMC) residues into AONs has divergent effects on RNA affinity. Incorporation of 2'-O-NMA-T considerably improves RNA affinity while incorporation of 2'-O-NMC-T drastically reduces RNA affinity. Crystal structures at high resolution of A-form DNA duplexes containing either 2'-O-NMA-T or 2'-O-NMC-T shed light on the structural origins of the surprisingly large difference in stability given the relatively minor difference in chemistry between NMA and NMC. NMA substituents adopt an extended conformation and use either their carbonyl oxygen or amino nitrogen to trap water molecules between phosphate group and sugar. The conformational properties of NMA and the observed hydration patterns are reminiscent of those found in the structures of 2'-O-MOE-modified RNA. Conversely, the carbonyl oxygen of NMC and O2 of T are in close contact, providing evidence that an unfavorable electrostatic interaction and the absence of a stable water structure are the main reasons for the loss in thermodynamic stability as a result of incorporation of 2'-O-NMC-modified residues.

Pattanayek, R.; Sethaphong, L.; Pan, C.; Prhavc, M.; Prakash, T.P.; Manoharan, M.; Egli, M. (Tennessee); (Isis Pharmaceuticals Inc.); (Alnylam Pharmaceuticals,); (Vanderbilt)

2010-03-08

301

Geothrix fermentans Secretes Two Different Redox-Active Compounds To Utilize Electron Acceptors across a Wide Range of Redox Potentials  

PubMed Central

The current understanding of dissimilatory metal reduction is based primarily on isolates from the proteobacterial genera Geobacter and Shewanella. However, environments undergoing active Fe(III) reduction often harbor less-well-studied phyla that are equally abundant. In this work, electrochemical techniques were used to analyze respiratory electron transfer by the only known Fe(III)-reducing representative of the Acidobacteria, Geothrix fermentans. In contrast to previously characterized metal-reducing bacteria, which typically reach maximal rates of respiration at electron acceptor potentials of 0 V versus standard hydrogen electrode (SHE), G. fermentans required potentials as high as 0.55 V to respire at its maximum rate. In addition, G. fermentans secreted two different soluble redox-active electron shuttles with separate redox potentials (?0.2 V and 0.3 V). The compound with the lower midpoint potential, responsible for 20 to 30% of electron transfer activity, was riboflavin. The behavior of the higher-potential compound was consistent with hydrophilic UV-fluorescent molecules previously found in G. fermentans supernatants. Both electron shuttles were also produced when cultures were grown with Fe(III), but not when fumarate was the electron acceptor. This study reveals that Geothrix is able to take advantage of higher-redox-potential environments, demonstrates that secretion of flavin-based shuttles is not confined to Shewanella, and points to the existence of high-potential-redox-active compounds involved in extracellular electron transfer. Based on differences between the respiratory strategies of Geothrix and Geobacter, these two groups of bacteria could exist in distinctive environmental niches defined by redox potential. PMID:22843516

Mehta-Kolte, Misha G.

2012-01-01

302

On the relationship between the tree and its environment, based on electrical potential difference monitoring on trunk of trees  

NASA Astrophysics Data System (ADS)

Electrical potential differences (EPD) in the trunk of a Turkey oak tree (measured by using non-polarising electrodes deepened in the sap wood) have been continuously recorded in the Geophysical Observatory "Istv n Széchenyi" of the Hungarian Academy of Sciences since 1997. Besides of various geophysical observations, meteorological and direct sap-flow measurements have also been carried out in the observatory. As it was found (Kopp n A., Szarka L., Wesztergom V., 2000: Annual fluctuation in amplitudes of daily variations of electrical signals measured in the trunk of a standing tree. C.R. Acad. Sci. Paris, Life Sciences 323, 559-563), the measured electric potential difference data have a characteristic sinusoidal daily fluctuation, and the intensity of the diurnal variations has a double-peak annual characteristics, which coincides with the life activity maximums of the tree. We have found a remarkable inter-correlation between trunk EPD, water potential of air (derived from meteorological data), and direct sap flow velocity data from a neighboring tree. All these results clearly demonstrate that the sap streaming due to the transpiration and root pressure generates the largest part of measured potential differences. The ratio of the flow velocity of a diluted solution forced through stems and the potential differences was found to be constant (Gindl, W., L”ppert, H.-G., Wimmer, R., 1999: Relationship between streaming potential and sap velocity in Salix alba L. Phyton, 39, 217-224.). On the contrary in our in-vivo experiments the relationship between the measured sap flow velocity and EPD is non-linear, which means that the conductivity (i.e. ion concentration) of the xylem sap itself also has a daily fluctuation.

Koppan, A.; Fenyvesi, A.; Szarka, L.; Wesztergom, V.

2002-05-01

303

Sex Discrimination in Grading in the Basic Course?: Removing Potential Explanations for Differences.  

ERIC Educational Resources Information Center

A study examined the differential grading that occurs in the basic speech communication classroom and attempted to identify predictors for the differences in the grades that male and female students receive. Subjects, 47 women and 48 men enrolled in the same lecture section of a basic communication course at a small private midwestern college,…

Pearson, Judy C.; Roberts, Charles

304

Difference, Ambiguity and Potential for Learning--Local Communities Working in Partnership with Local Government.  

ERIC Educational Resources Information Center

An action learning project for neighborhood regeneration in Coventry, England, showed that differences of power and viewpoint were inevitable and essential. More open networks enabling communication among community groups were needed. Funding for community networking needed to go beyond short-term projects supported by the current policy agenda.…

Blaxter, Loraine; Farnell, Richard; Watts, Jane

2003-01-01

305

Effect of compost, nitrogen salts, and NPK fertilizers on methane oxidation potential at different temperatures.  

PubMed

The effects of compost, nitrogen salts, and nitrogen-phosphorous-potassium (NPK) fertilizers on the methane oxidation potential (MOP) of landfill cover soil at various temperatures were assessed. For this, we used batch assays conducted at 5°C, 15°C, and 25°C with microcosms containing landfill cover soil slurries amended with these elements. Results indicated variable impacts dependent on the type of amendment and the incubation temperature. For a given incubation temperature, MOP varied from one compost to another and with the amount of compost added, except for the shrimp/peat compost. With this latter compost, independent of the amount, MOP values remained similar and were significantly higher than those obtained with other composts. Amendment with most of the tested nitrogen salts led to similar improvements in methanotrophic activity, except for urea. MOP with NPK fertilizer addition was amongst the highest in this study; the minimum value obtained with NPK (20-0-20) suggested the importance of P for methanotrophs. MOP generally increased with temperature, and nutrient limitation became less important at higher temperatures. Overall, at each of the three temperatures tested, MOP with NPK fertilizer amendments provided the best results and was comparable to those observed with the addition of the shrimp/peat compost. The results of this study provide the first evidence of the following: (1) compost addition to improve methanotrophic activity in a landfill cover soil should consider the amount and type of compost used and (2) the importance of using NPK fertilizers rather than nitrogen salts, in enhancing this activity, primarily at low temperatures. One can also consider the potential beneficial impact of adding these elements to enhance plant growth, which is an advantage for MOP. PMID:21894478

Jugnia, Louis-B; Mottiar, Yaseen; Djuikom, Euphrasie; Cabral, Alexandre R; Greer, Charles W

2012-03-01

306

Proficiency differences in syntactic processing of monolingual native speakers indexed by event-related potentials.  

PubMed

Although 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 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 on the basis of standardized proficiency scores into lower proficiency and higher proficiency groups. Compared with lower proficiency participants, higher proficiency 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 used 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-groups analyses. This approach also used 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 to fully characterize neural organization for language in native speakers it is necessary to include participants of varying proficiency. PMID:19925188

Pakulak, Eric; Neville, Helen J

2010-12-01

307

[Canakinumab, a monoclonal antibody against IL-1?, with potential utility in different inflammatory processes].  

PubMed

Canakinumab is a fully human monoclonal antibody targeted at IL-1? which has shown to be effective in the control the symptoms of patients affected by CAPS and other autoinflammatory diseases. Its effect is rapid and sustained. In clinical trials conducted up until now, the most common adverse effects reported with the use of this drug have been different types of infections, migraines and vertigo. PMID:21596185

Carné, Xavier

2011-01-01

308

Quantitative Approaches to Detect Donor and Passage Differences in Adipogenic Potential and Clonogenicity in Human Bone Marrow-Derived Mesenchymal Stem Cells  

PubMed Central

Bone marrow-derived multipotent stromal cells (MSCs), also known as mesenchymal stem cells, have great promise due to their capacity for tri-lineage differentiation and immunosuppressive properties, which allows for their allogeneic use and ultimately may allow for treatment of many diseases. MSCs will require extensive expansion and passaging to obtain cells in sufficient numbers necessary for cell therapies. MSCs from many donors could potentially be used. Because of this, there is a need to understand the role of passaging and donor differences on differentiation capacity using quantitative approaches. Here, we evaluated MSCs from two donors (noted as PCBM1632 and PCBM1641 by the manufacturer) at tissue culture passages 3, 5, and 7. We used a colony forming unit (CFU) assay and limiting dilution to quantify clonogenicity and precursor frequency during adipogenesis, and quantitative real-time-polymerase chain reaction for adipogenic markers to evaluate changes on a gene expression level. Further, we observed changes in cell size, and we sorted small and large populations to evaluate size-related adipogenic potential. While the adipogenic precursor frequency of ?1 in 76 cells remained similar through passages for cells from PCBM1641, we found a large decrease in the adipogenic potential of MSCs from PCBM1632, with 1 in 2035 cells being capable of differentiating into an adipocyte at passage 7. MSCs from both donors showed an increase in cell diameter with increasing passage, which correlates with a decrease in clonogenicity by CFU analysis. We also measured adipose lineage gene expression following induction of adipocyte differentiation. Expression of these genes decreased with passage number for MSCs from PCBM1632 and correlated with the decrease in adipogenic potential by passage 7. In contrast, MSCs from PCBM1641 showed increased expression of these genes with increasing passage. We have shown that several quantitative assays can detect differences in MSC differentiation capacity, clonogenicity, and cell size between donors and passages. These quantitative methods are useful to assess the quality of MSCs. PMID:22563812

Lo Surdo, Jessica

2012-01-01

309

Brainstem auditory evoked potentials in epileptics on different anti-epileptic drugs.  

PubMed

The effects of anti-epileptic drugs (AEDs) on brainstem auditory evoked potentials (BAEPs) were studied on 32 female patients of epilepsy and 10 age-matched normal healthy females (NS). The patients were divided into 6 groups, those not receiving medication (drug free, DF) and those receiving AEDs: Phenytoin (PHT), Carbamazepine (CBZ), Phenobarbital (PB), a combination of PHT and PB and a combination of CBZ and PB. DF epileptics had shortened were V absolute latency (AL) and I-V interpeak latency (IPL) as compared to NS. Phenytoin and CBZ monotherapy produced a prolongation of wave III AL (by PHT only), wave V AL, wave I-III IPL and I-V IPL, as compared to DF epileptics. Phenytoin monotherapy also prolonged wave III AL and I-III IPL, as compared to NS. When PB in the dosage of 30-60 mg/d was used in combination with PHT the above mentioned changes were not observed. These findings indicate altered neuronal conduction and/or synaptic transmission in epileptics. Anti-epileptic drugs in the dosages studied, with exception of PHT appear to lead towards "normalization" of BAEPs. PMID:8864768

Panjwani, U; Singh, S H; sel Vamurthy, W; Gupta, H L; Mukhopadhyay, S; Thakur, L

1996-01-01

310

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

PubMed

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

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

2014-07-01

311

Assessment of Antioxidant Potential, Total Phenolics and Flavonoids of Different Solvent Fractions of Monotheca Buxifolia Fruit  

PubMed Central

Objectives This study was conducted to investigate the antioxidant potential of methanol extract and its derived fractions (hexane, ethyl acetate, butanol, and aqueous) of fruits of Monotheca buxifolia (Falc.) Dc., a locally used fruit in Pakistan. Methods Dried powder of the fruit of M. buxifolia was extracted with methanol and the resultant was fractionated with solvents having escalating polarity; n-hexane, chloroform, ethyl acetate, n-butanol and the residual soluble aqueous fraction. Total phenolic and total flavonoid contents were estimated for the methanol and various fractions. These fractions were also subjected to various in vitro assays to estimate the scavenging activity for 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), superoxide, hydroxyl, hydrogen peroxide and reductive ability for ferric ions and phosphomolybdate assay. Results The n-butanol, aqueous and methanol fractions possessed high amount of phenolics and flavonoids compared with other fractions, and subsequently showed a pronounced scavenging activity on DPPH, ABTS, superoxide, hydroxyl and hydrogen peroxide radicals and had a potent reductive ability on ferric ion and phosphomolybdate assay. There was a found significant correlation between total phenolic and flavonoid contents and EC50 of DPPH, superoxide, hydrogen peroxide radical and phosphomolybdate assays, whereas a nonsignificant correlation was found with the hydroxyl radical and ABTS radical assay. Conclusion M. buxifolia fruit can be used as natural antioxidant source to prevent damage associated with free radicals. PMID:24298440

Jan, Shumaila; Khan, Muhammad Rashid; Rashid, Umbreen; Bokhari, Jasia

2013-01-01

312

Event-related potentials in adolescents with different cognitive styles: field dependence and field independence.  

PubMed

Field dependence/independence (FD/FI) is an important dimension of personality and cognitive styles. Different ability in mobilizing and/or allocating mental-attentional capacity was considered to be the most possible explanation for the FDI cognitive style. Many studies on characterizing the functional neuroanatomy of attentional control indicated the existence of a dissociable sub-process of conflict-monitoring and "cognitive control" system. However, little was known about it. We might dissociate "cognitive control" system from conflict processing by taking advantage of the variable of the FDI cognitive style. In addition, essentially cognitive styles (FDI) are often widely studied in psychological and educational fields, but hardly in neuroscience. We speculated that ERP components could help to explain the difference between how FD and FI individuals process information. The purpose of the reported study was to explore the possible relation between the "cognitive control" system and the conflict processing system during stimulus-matching task. We first characterized the standard FD/FI of senior-high-school Han students in grade two in Beijing, China, based on 160 students with similar age, education, living and cultural background. Twenty-six adolescents were selected and divided into two groups (extreme FD group and extreme FI group) according to their Group Embedded Figures Test (GEFT) results (FD: 5-8; FI: 17-19). They were tested on both Wechsler Adult Intelligence Scale (WAIS) and stimulus-matching task. ERP was measured while the subjects performed the stimulus-matching tasks by categorizing two figures that were presented sequentially either as a match (same shape) or as a conflict (different shape) conditions. The results showed that the mean amplitude of N270 in FI group was higher relative to that in FD group at nearly all centrofrontal areas in the conflict condition. We conclude that the FDI cognitive styles could influence the conflict processing by the "cognitive control" system due to the different abilities of FD and FI subjects in mobilizing and/or allocating attentional resources, which can be indexed by N270. PMID:22076405

Meng, Xianghong; Mao, Wei; Sun, Wei; Zhang, Xiating; Han, Chunyu; Lu, Changfeng; Huang, Zhaoyang; Wang, Yuping

2012-01-01

313

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

SciTech Connect

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.

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

314

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

SciTech Connect

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.

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

315

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

NASA Technical Reports Server (NTRS)

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.

Jekeli, C.

1979-01-01

316

Expansion of Scaling Law of Field-Aligned Potential Difference with Increased Plug ECRH Power in GAMMA 10  

NASA Astrophysics Data System (ADS)

The high power operation of gyrotrons exceeding their nominal powers has been carried out for ECRH at the plug region in the GAMMA 10 tandem mirror device. The highest recorded value of the axial ion confining potential for a hot ion mode plasma has been obtained. The mean energy Teff of the axially flowing electrons driven by the plug ECRH increases to 3 keV according to the increase in the heating power up to 260 kW. The maximum field-aligned potential difference ?? has reached 5.5 kV and the scaling law between ?? and Teff has expanded.

Saito, Teruo; Tatematsu, Yoshinori; Ikegami, Hirokazu; Sekine, Takayuki; Nagai, Daichi; Nozaki, Kiyoshi; Yoshida, Maiko; Ishii, Kameo; Cho, Teruji

317

"Have You Ever Seen This Face?" - Individual Differences and Event-Related Potentials during Deception  

PubMed Central

Deception studies emphasize on the importance of event-related potentials (ERP) for a reliable differentiation of the underlying neuro-cognitive processes. The stimulus-locked parietal P3 amplitude has been shown to reflect stimulus salience but also attentional control available for stimulus processing. Known stimuli requiring truthful responses (targets) and known stimuli requiring deceptive responses (probes) were hypothesized to be more salient than unknown stimuli. Thus, a larger P3 was predicted for known truthful and deceptive stimuli than for unknown stimuli. The Medial Frontal Negativity (MFN) represents the amount of required cognitive control and was expected to be more negative to known truthful and deceptive stimuli than to unknown stimuli. Moreover, we expected higher sensitivity to injustice (SI-perpetrator) and aversiveness (Trait-BIS) to result in more intense neural processes during deception. N?=?102 participants performed a deception task with three picture types: probes requiring deceptive responses, targets requiring truthful responses to known stimuli, and irrelevants being associated with truthful responses to unknown stimuli. Repeated-measures ANOVA and fixed-links modeling suggested a more positive parietal P3 and a more negative frontal MFN to deceptive vs. irrelevant stimuli. Trait-BIS and SI-perpetrator predicted an increase of the P3 and a decrease of the MFN from irrelevants to probes. This suggested an intensification of stimulus salience and cognitive control across picture types in individuals scoring either higher on Trait-BIS or higher on SI-perpetrator. In contrast, individuals with both higher Trait-BIS and higher SI-perpetrator scores showed a less negative probe-MFN suggesting that this subgroup invests less cognitive control to probes. By extending prior research we demonstrate that personality modulates stimulus salience and control processes during deception. PMID:23267339

Leue, Anja; Lange, Sebastian; Beauducel, Andre

2012-01-01

318

Effect of different steam explosion conditions on methane potential and enzymatic saccharification of birch.  

PubMed

Birch (Betula pubescens) was steam exploded at 13 different conditions with temperatures ranging from 170 to 230 °C and residence times ranging from 5 to 15 min. Increasing severity in the pretreatment led to degradation of xylan and formation of pseudo-lignin. The effect of the pretreatments was evaluated by running enzymatic saccharification and anaerobic digestion followed by analysis of sugar and methane yields, respectively. Enzymatically released glucose increased with pretreatment severity up to 220 °C for 10 min and levels of solubilized glucose reached 97% of the theoretical maximum. The highest methane yield (369 mL gVS(-1)) was obtained at a severity factor of 4.5 and this yield was 1.8 times higher than the yield from untreated birch. Enzymatic glucose yields and methane yields were generally correlated. The results indicate that steam-exploded birch can be effectively converted to either glucose or methane. PMID:23131658

Vivekanand, Vivekanand; Olsen, Elisabeth F; Eijsink, Vincent G H; Horn, Svein J

2013-01-01

319

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

PubMed Central

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

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

2013-01-01

320

Transient receptor potential: a large family of new channels of which several are involved in cardiac arrhythmia.  

PubMed

The transient receptor potential (TRP) family of ion channels comprises more than 50 cation-permeable channels expressed throughout the animal kingdom. TRPs can be grouped into 7 main subfamilies according to structural homology: the TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPP (polycystin), TRPML (mucolipin), TRPA (ankyrin), and TRPN (NO mechanopotential). During the past 20 years, the cloning and characterization after reexpression of most members of these cation channels have led to a plethora of data and more recently to some understanding of their roles in various cells and tissues. Specifically in the heart, TRPs are known to be involved in various diseases, including hypertrophy, heart failure, and arrhythmia. The later part of this review focuses on the potential contribution of TRPs to cardiac rhythm and their potential proarrhythmic effects. Furthermore, several neurotransmitters that activate the formation of diacylglycerol could modulate cardiac rhythm or, like ATP, induce arrhythmia. PMID:19234573

Vassort, Guy; Alvarez, Julio

2009-02-01

321

Narrowing Sex Differences in Lipoprotein Cholesterol Subclasses Following Mid-Life: The Very Large Database of Lipids (VLDL-10B)  

PubMed Central

Background Women have less risk of atherosclerotic cardiovascular disease compared with men up until midlife (ages 50 to 60), after which the gap begins to narrow post menopause. We hypothesized that the average lipid profile of women undergoes unfavorable changes compared with men after midlife. Methods and Results We examined lipids by sex and age in the Very Large Database of Lipids 10B (VLDL 10B) study. The analysis included 1 350 908 unique consecutive patients clinically referred for lipoprotein testing by density gradient ultracentrifugation from 2009 to 2011. Ratio variables were created for density subclasses of LDL?C, HDL?C, and VLDL?C (LLDR, LHDR, LVDR, respectively). Men showed higher median LDL?C values than women for ages 20 to 59, with the greatest difference in their 30s: 146 mg/dL in men versus 130 mg/dL in women. In contrast, women consistently had higher values after midlife (age 60), for example ages 70 to 79: 129 mg/dL in women versus 112 mg/dL in men. After age 50, women had higher LDL?C each decade, for example 14% higher from their 30s to 50s, while HDL?C concentrations did not differ. Women had more buoyant LDL?C and HDL?C (lower LLDR and LHDR) than men at all ages but the gap closed in higher age groups. In contrast, women had a generally denser VLDL?C (higher LVDR) leading into midlife, with the gap progressively closing in higher age groups, approximating that of men in their 60s and 70s. Conclusion The narrowing sex differential in cardiovascular disease risk after midlife is mirrored by a higher total atherogenic lipoprotein cholesterol burden in women and a closer approximation of the less favorable density phenotype characteristic of men. PMID:24755154

Swiger, Kristopher J.; Martin, Seth S.; Blaha, Michael J.; Toth, Peter P.; Nasir, Khurram; Michos, Erin D.; Gerstenblith, Gary; Blumenthal, Roger S.; Jones, Steven R.

2014-01-01

322

Opposite Membrane Potential Changes Induced by Glucose Deprivation in Striatal Spiny Neurons and in Large Aspiny Interneurons  

Microsoft Academic Search

We have studied the electrophysiological effects of glucose deprivation on morphologically identified striatal neurons re- corded from a corticostriatal slice preparation. The large ma- jority of the recorded cells were spiny neurons and responded to aglycemia with a slow membrane depolarization coupled with a reduction of the input resistance. In voltage-clamp ex- periments aglycemia caused an inward current. This current

Paolo Calabresi; Carlos Magarinos Ascone; Diego Centonze; Antonio Pisani; Giuseppe Sancesario; Vincenza D'Angelo; Giorgio Bernardi

1997-01-01

323

Bioavailability and antioxidant potential of rooibos flavonoids in humans following the consumption of different rooibos formulations.  

PubMed

In a complete crossover design, a human study with twelve healthy male volunteers has been conducted using a placebo and different rooibos drinks (rooibos tea and an isolated active fraction) from unfermented rooibos (Aspalathus linearis). Blood and urine samples were collected before and up to 24h after consumption of the drinks. By HPLC-MS/MS, seven metabolites of aspalathin and nothofagin were identified in urine samples, as well as intact aspalathin and nothofagin. Moreover, sulphated, glucuronidated, methylated, both glucuronidated and methylated aspalathin, and glucuronidates of the aglycones of aspalathin and nothofagin were detected. The main metabolite excreted was methylated aspalathin. Most of the metabolites were detected after administration of both rooibos formulations. In plasma samples characteristic unchanged flavonoids derived from unfermented rooibos (e.g. aspalathin) were detected in trace quantities this is due to the changes in Table 5 after ingestion of both rooibos formulations. On average a total of 0.76nmol of flavonoids were detected during their peak concentration after intake of the rooibos tea, accounting for 0.26% compared to the total amount of flavonoids ingested. Despite the comparable intake of total flavonoids, only an overall 0.41nmol of flavonoids could be detected after ingestion of the isolated active fraction. No significant increase in plasma antioxidant capacity was observed using the ORAC assay giving rise to the assumption that the effects of rooibos flavonoids have to be detected using other endpoints. PMID:25212140

Breiter, Till; Laue, Christian; Kressel, Gaby; Gröll, Stephanie; Engelhardt, Ulrich H; Hahn, Andreas

2011-09-15

324

Bacterial colonization on different suture materials--a potential risk for intraoral dentoalveolar surgery.  

PubMed

In this in vivo and in vitro study on resorbable (Monocryl and nonresorbable (Deknalon) monofilament sutures used in intraoral dentoalveolar surgery the bacterial colonization was compared. For the in vivo study the sutures were applied in 11 patients during dental surgery. Eight days postoperative the sutures were removed and the adhered bacteria were isolated and identified by biochemistry, morphology, antibiotic susceptibility, and gas chromatography. The colonization was studied by scanning electron microscopy. Aerobic and anaerobic bacteria were isolated in nearly equal colony-forming units (cfu) on each suture. In comparison with Monocryl about 15% more aerobic and anaerobic strains were isolated on Deknalon. Regarding the pathogens only, about three times more anaerobic strains were isolated on both sutures in total. Additionally, more pathogens were found on Deknalon than on Monocryl (aerobic >40%, anaerobic >25%). The variety of bacteria correspond with purulent infections, not with normal oral flora. Intraindividual comparisons of cfu showed differences in dependence of the patient as described for subgingivale plaques. For the in vitro study the sutures were incubated with Streptococcus intermedius and Prevotella intermedia for 0.5 h. Scanning electron microscopy was performed to examine qualitatively the level of bacterial adherence. After 0.5 h the bacteria adhered very well. The colonization rate of Streptococcus intermedius on both sutures was similar. Coccoid bacteria within biofilms were seen. The growth of Prevotella intermedia was much better on Deknalon than on Monocryl. The risk of bacteremia at the time of suture removal is discussed. PMID:15889436

Otten, J-E; Wiedmann-Al-Ahmad, M; Jahnke, H; Pelz, K

2005-07-01

325

Gender differences in cholesterol nucleation in native bile: estrogen is a potential contributory factor.  

PubMed

The incidence of gallstone disease is two to three times higher in women than in men, and female sex hormones, particularly estrogens, have been implicated as contributory factors. Cholesterol nucleation is the initial step in gallstone pathogenesis and proceeds from cholesterol-rich phospholipid vesicles. The aim of this study was to investigate if there is a difference in cholesterol nucleation rates in male and female bile and whether estrogen influences nucleation rates by interacting with cholesterol-rich regions known as "lipid rafts" that exist within the cholesterol-phospholipid vesicles of the bile. Cholesterol nucleation from native prairie dog bile and the interaction of estrogens with lipid rafts in model bile solutions were investigated using Förster resonance energy transfer (FRET). Female native bile samples showed a greater reduction in energy transfer than did male native bile, indicating that cholesterol nucleation occurred more readily in female bile than in male bile. Model bile experiments demonstrated that the addition of estrogen has a significant effect, either cholesterol nucleation or raft disruption, but only in samples containing cholesterol-rich rafts. These results suggest that estrogen interacts with cholesterol-rich rafts in vesicles within bile to promote cholesterol nucleation and predispose females to gallstone formation. PMID:19898891

Brown, Angela C; Wrenn, Steven P; Suresh, Nandita; Meyers, William C; Abedin, Mohammad Z

2009-12-01

326

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

SciTech Connect

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.

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

327

Lattice dynamical analogies and differences between SrTiO3 and EuTiO3 revealed by phonon-dispersion relations and double-well potentials  

NASA Astrophysics Data System (ADS)

A comparative analysis of the structural phase transitions of EuTiO3 and SrTiO3 (at TS = 282 and 105 K, respectively) is made on the basis of phonon-dispersion and density functional calculations. The phase transition of EuTiO3 is predicted to arise from the softening of a transverse acoustic zone boundary mode caused by the rotations of the TiO6 octahedra, as also found for the phase transition of SrTiO3. Although the temperature dependence of the soft mode is similar in both compounds, their elastic properties differ drastically because of a large difference in the double-well potentials associated with the soft zone boundary acoustic mode.

Bettis, Jerry L.; Whangbo, Myung-Hwan; Köhler, Jürgen; Bussmann-Holder, Annette; Bishop, A. R.

2011-11-01

328

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

PubMed

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

Lin, Jiajiang; He, Yan; Xu, Jianming

2012-11-01

329

The potential for long-term persistence of forest fragments on Tongatapu, a large island in western  

Microsoft Academic Search

Aim We describe compositional variation among forest fragments on Tongatapu in terms of successional status and site conditions. We then examine two factors that directly influence the potential for long-term persistence of these fragments - tree regeneration and alien invasion. Location Tongatapu is the largest (261 km2), most densely inhabited (population 67,000) island in the Kingdom of Tonga, western Polynesia.

Susan K. Wiser; Donald R. Drake; Larry E. Burrows; William R. Sykes

2002-01-01

330

Somatosensory evoked potential spinal cord monitoring reduces neurologic deficits after scoliosis surgery: results of a large multicenter survey  

Microsoft Academic Search

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

Marc R. Nuwer; Edgar G. Dawson; Linda G. Carlson; Linda E. A. Kanim; John E. Sherman

1995-01-01

331

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

PubMed

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

Abdallah, Maha Ahmed Mohamed

2013-08-01

332

Soil phosphorus levels needed for equal P uptake from four soils with different water contents at the same water potential  

Microsoft Academic Search

Soil volumetric water contents, ?, at ?33 kPa potential may vary with soil from 0.06 to 0.70. Because P diffusion depends on ?, most economic P fertilizer rates required for different soils may require adjusting according to their soil-water relationships. The objective of this study was, after experimentally verifying a mechanistic nutrient uptake model on a series of soils varying

M. S. Cox; S. A. Barber

1992-01-01

333

Potential of Thlaspi caerulescens for Cadmium Phytoremediation: Comparison of Two Representative Soil Types in Japan under Different Planting Frequencies  

Microsoft Academic Search

To assess the potential of the Cd hyperaccumulator Thlaspi caerulescens (Ganges ecotype) for Cd phytoremediation in Japan, we compared the changes in the soil Cd concentration between a Fluvisol and an Andosol and the efficiency of Cd removal under different planting frequencies in a pot experiment. The soils were artificially contaminated with Cd(NO3)2 to the level of about 5 mg

Yuko Nishiyama; Junta Yanai; Takashi Kosaki

2005-01-01

334

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

NASA Astrophysics Data System (ADS)

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

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

2009-04-01

335

The abnormalities of chromosome 8 in two hepatocellular carcinoma cell clones with the same genetic background and different metastatic potential  

Microsoft Academic Search

Purpose. Two hepatocellular carcinoma (HCC) cell clones named MHCC97-H and MHCC97-L with different metastatic potential have recently been established from the same parent cell line MHCC97 in our institute. The cytogenetic alterations of these two clones were investigated in this study to explore the possible clues to the mechanism involved in HCC metastasis.Methods. Their chromosomal aberrations were analyzed with comparative

Jiong Yang; Lun-Xiu Qin; Sheng-Long Ye; Yin-Kun Liu; Yan Li; Dong-Mei Gao; Jie Chen; Zhao-You Tang

2003-01-01

336

The large-leaved Kudingcha (Ilex latifolia Thunb and Ilex kudingcha C.J. Tseng): a traditional Chinese tea with plentiful secondary metabolites and potential biological activities.  

PubMed

In China, Kudingcha has been used for almost 2,000 years as a tea to quench thirst, remove phlegm, refresh the mind, and improve eyesight. The group of large-leaved Kudingcha is coveted for its potential effects on lipid metabolism, which are attributed to the presence of characteristic ingredients. This contribution reviews studies from the past few decades regarding the plant characteristics, ethnobotanical usages, chemical constituents, and related biological activities of the large-leaved Kudingcha (Ilex latifolia Thunb and Ilex kudingcha C.J. Tseng). Triterpenoids, phenolic acids, flavonoids, and essential oils are the main metabolites in the large-leaved Kudingcha, and these ingredients protect the vascular system, regulate lipid metabolism, and have antioxidant, hypoglycemic, and anti-tumor effects. Moreover, large-leaved Kudingcha shares several properties with the popular green tea and the Yerba maté from South America. PMID:23529541

Li, Li; Xu, Li J; Ma, Gui Z; Dong, Yin M; Peng, Yong; Xiao, Pei G

2013-07-01

337

Differences in the dynamics and potential production of impounded and unimpounded white sturgeon populations in the lower Columbia River  

SciTech Connect

White sturgeons Acipenser transmontanus were sampled in three lower Columbia River reservoirs from 1987 to 1991 to describe population dynamics, the ability of these stocks to sustain harvest, and differences among reservoir and unimpounded populations. Significant differences were observed among reservoirs in white sturgeon abundance, biomass, size composition, sex ratio, size of females at maturity, growth rate, condition factor, and rate of exploitation. No differences among reservoirs were detected in fecundity, natural mortality rate, or longevity, in part because of sampling difficulties. Recruitment rates and densities in reservoirs were inversely correlated with growth rate, condition factor, and size of females at maturity. Differences in population dynamics resulted in substantial differences in sustainable yields. Maximum yields per recruit were predicted at annual exploitation rates between 5 and 15%. Most characteristics of reservoir populations were less than or equal to optima reported for the unimpounded lower river; as a result, yield per recruit, reproductive potential per recruit, and the number of recruits were less in reservoirs than in the unimpounded river. Comparisons with pristine standing stocks suggest that the unimpounded river may approximate preimpoundment conditions for white sturgeon. We conclude that potential yield from impounded populations has been reduced by dam construction, which restricts populations to river segments that may not include conditions optimal for all life stages. Alternatives for enchancement of reservoir populations might include improved passage at dams, increased spring flow to improve spawning success, transplants from productive populations, hatchery supplementation, and more intensive harvest management. 54 refs., 7 figs., 7 tabs.

Beamesderfer, R.C.P.; Rien, T.A.; Nigro, A.A. [Oregon Department of Fish and Wildlife, Clackamas, OR (United States)

1995-11-01

338

Characterization and differentiation potential of rat ventral mesencephalic neuronal progenitor cells immortalized with SV40 large T antigen  

Microsoft Academic Search

Neuronal progenitor cells (NPCs) possess high potential for use in regenerative medicine. To overcome their limited mitotic\\u000a competence, various immortalization strategies have been applied that allow their prolonged maintenance and expansion in vitro.\\u000a Such immortalized cells can be used for the design and discovery of new cell-based therapies for neurodegenerative diseases,\\u000a such as Parkinson’s disease. We immortalized rat ventral mesencephalic

André Nobre; Ieva Kalve; Konstantin Cesnulevicius; Daniela Rangancokova; Andreas Ratzka; Nina Halfer; Maike Wesemann; Klaus Krampfl; Peter Claus; Claudia Grothe

2010-01-01

339

Clinical characteristics associated with different strengths of loudness dependence of auditory evoked potentials (LDAEP) in major depressive disorder.  

PubMed

Loudness dependence of auditory evoked potentials (LDAEP), also called as intensity dependence of auditory evoked potentials (IDAP), has been proposed as a potential marker for central serotonergic tone and has been noticed for its possible clinical implications in depression. However, its distributions in major depressive disorder (MDD) and factors affecting it are largely unknown. In this study, we examined its distribution and relationships with various demographic and clinical variables in MDD patients. In 143 MDD patients, the LDAEP was measured using five intensities of auditory stimulus. The influences of ten independent variables (age, gender, education years, marital status, psychiatric family history, age of onset, suicide attempt history, depression severity, later augmentation of mood stabilizer, and smoking status) on the LDAEP strength were examined using univariate analyses and data mining method. The mean (±S.D.) LDAEP was 0.90 (±0.73)?V/10dB (-0.78-3.83?V/10dB). Female gender, smoking, and being married were consistently associated with a weaker LDAEP. In the pathway model, sequential combination of being male, living alone, and older age predicted the strongest LDAEP, whereas female gender, older age, and smoking predicted the weakest LDAEP. These variables need to be considered when interpreting the LDAEP. PMID:23021319

Min, Jung-Ah; Lee, Seung-Hwan; Lee, Seung-Yup; Chae, Jeong-Ho; Lee, Chang-Uk; Park, Young-Min; Bae, Sung-Man

2012-12-30

340

Selection for Unequal Densities of Sigma70 Promoter-like Signalsin Different Regions of Large Bacterial Genomes  

SciTech Connect

The evolutionary processes operating in the DNA regions that participate in the regulation of gene expression are poorly understood. In Escherichia coli, we have established a sequence pattern that distinguishes regulatory from nonregulatory regions. The density of promoter-like sequences, that are recognizable by RNA polymerase and may function as potential promoters, is high within regulatory regions, in contrast to coding regions and regions located between convergently-transcribed genes. Moreover, functional promoter sites identified experimentally are often found in the subregions of highest density of promoter-like signals, even when individual sites with higher binding affinity for RNA polymerase exist elsewhere within the regulatory region. In order to investigate the generality of this pattern, we have used position weight matrices describing the -35 and -10 promoter boxes of E. coli to search for these motifs in 43 additional genomes belonging to most established bacterial phyla, after specific calibration of the matrices according to the base composition of the noncoding regions of each genome. We have found that all bacterial species analyzed contain similar promoter-like motifs, and that, in most cases, these motifs follow the same genomic distribution observed in E. coli. Differential densities between regulatory and nonregulatory regions are detectable in most bacterial genomes, with the exception of those that have experienced evolutionary extreme genome reduction. Thus, the phylogenetic distribution of this pattern mirrors that of genes and other genomic features that require weak selection to be effective in order to persist. On this basis, we suggest that the loss of differential densities in the reduced genomes of host-restricted pathogens and symbionts is the outcome of a process of genome degradation resulting from the decreased efficiency of purifying selection in highly structured small populations. This implies that the differential distribution of promoter-like signals between regulatory and nonregulatory regions detected in large bacterial genomes confers a significant, although small, fitness advantage. This study paves the way for further identification of the specific types of selective constraints that affect the organization of regulatory regions and the overall distribution of promoter-like signals through more detailed comparative analyses among closely-related bacterial genomes.

Huerta, Araceli M.; Francino, M. Pilar; Morett, Enrique; Collado-Vides, Julio

2006-03-01

341

Germination responses to temperature and water potential in Jatropha curcas seeds: a hydrotime model explains the difference between dormancy expression and dormancy induction at different incubation temperatures  

PubMed Central

Background and Aims Jatropha curcas is a drought-resistant tree whose seeds are a good source of oil that can be used for producing biodiesel. A successful crop establishment depends on a rapid and uniform germination of the seed. In this work we aimed to characterize the responses of J. curcas seeds to temperature and water availability, using thermal time and hydrotime analysis, Methods Thermal and hydrotime analysis was performed on germination data obtained from the incubation of seeds at different temperatures and at different water potentials. Key Results Base and optimum temperatures were 14·4 and 30 °C, respectively. Approximately 20 % of the seed population displayed absolute dormancy and part of it displayed relative dormancy which was progressively expressed in further fractions when incubation temperatures departed from 25 °C. The thermal time model, but not the hydrotime model, failed to describe adequately final germination percentages at temperatures other than 25 °C. The hydrotime constant, ?H, was reduced when the incubation temperature was increased up to 30 °C, the base water potential for 50 % germination,?b(50), was less negative at 20 and 30 °C than at 25 °C, indicating either expression or induction of dormancy. At 20 °C this less negative ?b(50) explained satisfactorily the germination curves obtained at all water potentials, while at 30 °C it had to be corrected towards even less negative values to match observed curves at water potentials below 0. Hence, ?b(50) appeared to have been further displaced to less negative values as exposure to 30 °C was prolonged by osmoticum. These results suggest expression of dormancy at 20 °C and induction of secondary dormancy above 25 °C. This was confirmed by an experiment showing that inhibition of germination imposed by temperatures higher than 30 °C, but not that imposed at 20 °C, is a permanent effect. Conclusions This study revealed (a) the extremely narrow thermal range within which dormancy problems (either through expression or induction of dormancy) may not be encountered; and (b) the high sensitivity displayed by these seeds to water shortage. In addition, this work is the first one in which temperature effects on dormancy expression could be discriminated from those on dormancy induction using a hydrotime analysis. PMID:21917817

Windauer, Liliana B.; Martinez, J.; Rapoport, D.; Wassner, D.; Benech-Arnold, Roberto

2012-01-01

342

The movement of molecules and nanoparticles in potential field with the Casimir force in nano volumes with different optical boundaries  

NASA Astrophysics Data System (ADS)

This work is devoted to the problem of dynamics of molecules and nanoparticles in fields in following potentials: the Casimir force, the van der Waals interactions, the Coulomb potential for charged particles, the potential energies for bonds, and the electric potential. In the general case, molecules or nanoparticles move in nano volumes with walls of different optical properties. In particular, the matter at boundary can be with zero refracted index (Vesseur E J R et al 2013 Phys. Rev. Lett. 110 013902; Uvarova L A 2005 AIP congress). Current model can be used to investigate dynamical and configuration properties of particle systems, and to determine influences of molecules interactions with the walls. It is accepted that the Casimir force affects the velocity distribution function, the total energy, and equilibrium properties that produce rise of temperature, pressure and energy deviations. In many-atom molecules or nanoparticles interactions with the Casimir force are more complex, but they give opportunity to control admixtures and modification of system under the influence of electromagnetic waves.

Uvarova, L. A.; Babarin, S. S.

2014-09-01

343

Small vs. large dust grains in transitional disks: do different cavity sizes indicate a planet?. SAO 206462 (HD 135344B) in polarized light with VLT/NACO  

NASA Astrophysics Data System (ADS)

Context. Transitional disks represent a short stage of the evolution of circumstellar material. Studies of dust grains in these objects can provide pivotal information on the mechanisms of planet formation. Dissimilarities in the spatial distribution of small (?m-size) and large (mm-size) dust grains have recently been pointed out. Aims: Constraints on the small dust grains can be obtained by imaging the distribution of scattered light at near-infrared wavelengths. We aim at resolving structures in the surface layer of transitional disks (with particular emphasis on the inner 10-50 AU), thus increasing the scarce sample of high-resolution images of these objects. Methods: We obtained VLT/NACO near-IR high-resolution polarimetric differential imaging observations of SAO 206462 (HD 135344B). This technique allows one to image the polarized scattered light from the disk without any occulting mask and to reach an inner working angle of ~0.1?. Results: A face-on disk is detected in H and Ks bands between 0.1? and 0.9?. No significant differences are seen between the H and Ks images. In addition to the spiral arms, these new data allow us to resolve for the first time an inner disk cavity for small dust grains. The cavity size (?28 AU) is much smaller than what is inferred for large dust grains from (sub-)mm observations (39 to 50 AU). This discrepancy cannot be ascribed to any resolution effect. Conclusions: The interaction between the disk and potential orbiting companion(s) can explain both the spiral arm structure and the discrepant cavity sizes for small and large dust grains. One planet may be carving out the gas (and, thus, the small grains) at 28 AU, and generating a pressure bump at larger radii (39 AU), which holds back the large grains. We analytically estimate that, in this scenario, a single giant planet (with a mass between 5 and 15 MJ) at 17 to 20 AU from the star is consistent with the observed cavity sizes. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under program number 089.C-0611(A).Reduced data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/560/A105

Garufi, A.; Quanz, S. P.; Avenhaus, H.; Buenzli, E.; Dominik, C.; Meru, F.; Meyer, M. R.; Pinilla, P.; Schmid, H. M.; Wolf, S.

2013-12-01

344

To tweet, or not to tweet: gender differences and potential positive and negative health outcomes of adolescents' social internet use.  

PubMed

Adolescents and young adults are avid Internet users. Online social media, such as social networking sites (e.g., Facebook, MySpace), blogs, status updating sites (e.g., Twitter) and chat rooms, have become integral parts of adolescents' and young adults' lives. Adolescents are even beginning to enter the world of online dating with several websites dedicated to "teenage online dating." This paper reviews recent peer-reviewed literature and national data on 1) adolescents use of online social media, 2) gender differences in online social media and 3) potential positive and negative health outcomes from adolescents' online social media use. We also examine parental monitoring of adolescents' online activities. Given that parental supervision is a key protective factor against adolescent risk-taking behavior, it is reasonable to hypothesize that unmonitored Internet use may place adolescents' at significant risk, such as cyberbullying, unwanted exposure to pornography, and potentially revealing personal information to sexual predators. PMID:20164062

Pujazon-Zazik, Melissa; Park, M Jane

2010-03-01

345

EFM data mapped into 2D images of tip-sample contact potential difference and capacitance second derivative.  

PubMed

We report a simple technique for mapping Electrostatic Force Microscopy (EFM) bias sweep data into 2D images. The method allows simultaneous probing, in the same scanning area, of the contact potential difference and the second derivative of the capacitance between tip and sample, along with the height information. The only required equipment consists of a microscope with lift-mode EFM capable of phase shift detection. We designate this approach as Scanning Probe Potential Electrostatic Force Microscopy (SPP-EFM). An open-source MATLAB Graphical User Interface (GUI) for images acquisition, processing and analysis has been developed. The technique is tested with Indium Tin Oxide (ITO) and with poly(3-hexylthiophene) (P3HT) nanowires for organic transistor applications. PMID:24284731

Lilliu, S; Maragliano, C; Hampton, M; Elliott, M; Stefancich, M; Chiesa, M; Dahlem, M S; Macdonald, J E

2013-01-01

346

EFM data mapped into 2D images of tip-sample contact potential difference and capacitance second derivative  

NASA Astrophysics Data System (ADS)

We report a simple technique for mapping Electrostatic Force Microscopy (EFM) bias sweep data into 2D images. The method allows simultaneous probing, in the same scanning area, of the contact potential difference and the second derivative of the capacitance between tip and sample, along with the height information. The only required equipment consists of a microscope with lift-mode EFM capable of phase shift detection. We designate this approach as Scanning Probe Potential Electrostatic Force Microscopy (SPP-EFM). An open-source MATLAB Graphical User Interface (GUI) for images acquisition, processing and analysis has been developed. The technique is tested with Indium Tin Oxide (ITO) and with poly(3-hexylthiophene) (P3HT) nanowires for organic transistor applications.

Lilliu, S.; Maragliano, C.; Hampton, M.; Elliott, M.; Stefancich, M.; Chiesa, M.; Dahlem, M. S.; MacDonald, J. E.

2013-11-01

347

Difference  

NSDL National Science Digital Library

This interactive Flash applet models the difference meaning of subtraction. A child or teacher can compare two rows of beads and analyze the calculation they represent. Once a user sets up the two rows of beads (up to 30 each), the applet provides a series of animations which represents the rows with two number lines and then as a single number line with the difference indicated by a "jump". This applet works well with an interactive white board. A teacher's guide to this series of applets is cataloged separately.

2006-01-01

348

Challenges in implementing enterprise resource planning (ERP) system in large organizations : similarities and differences between corporate and university environment  

E-print Network

Enterprise resource planning (ERP) system has been one of the most popular business management systems, providing benefits of real-time capabilities and seamless communication for business in large organizations. However, ...

Seo, Goeun

2013-01-01

349

Amplification of a fast wave by extracting both the kinetic energy and electrostatic potential energy of a large-orbit relativistic electron beam in a coaxial electrostatic wiggler  

SciTech Connect

Nonlinear model and simulation technique of the interaction and energy transfer between a fast wave and a large-orbit relativistic electron beam in a coaxial electrostatic wiggler are presented. Unlike the situations in a magnetostatic-wiggler free-electron laser (MWFEL) and in an electron cyclotron maser (ECM), the electrostatic potential of the electrons plays an important role and participates in the energy exchange between the wave and the electron beam. Compared to MWFEL and ECM, the coaxial electrostatic-wiggler configuration has a distinguishing peculiarity that besides the electron-beam's kinetic energy, its electrostatic potential energy can be effectively transferred to the fast wave. Simulation shows that wave could be amplified with ultrahigh gain by extracting both the kinetic energy and electrostatic potential energy of the electron beam.

Zhang Shichang [Institute of Photoelectronics, Campus Mail Box 50, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)

2010-05-15

350

Global analytical potential hypersurfaces for large amplitude nuclear motion and reactions in methane. I. Formulation of the potentials and adjustment of parameters to ab initio data and experimental constraints  

NASA Astrophysics Data System (ADS)

Analytical representations of the global potential energy surface of XYn molecules are developed and applied to model the potential surface of methane in the electronic ground state. The generic analytical representation allows for a compact, robust, and flexible description of potentials for XYn systems irrespective of the specific nature of the atomic interactions. The functions are global in that structures near several minima of the potential hypersurface as well as saddle points and dissociation limits are well described. Clusters of atoms Yn can be represented as well by this type of function. Care is taken to implement conditions resulting from the symmetric group Sn and to construct positive definite bilinear forms of special functional forms of certain coordinates (such as bond lengths and bond angles), in order to avoid artifacts in exceptional ranges of the potential hypersurface. These special functional forms include intrinsic, symmetry allowed couplings between coordinates such as bending and stretching. We include linear potential terms in bond angle coordinates, which result in effectively quadratic potential terms for highly symmetric structures. True logical multidimensional 01-switching functions Ssw(r) of bond lengths r are used to interpolate between limiting ranges in the hypersurface. The particular form Ssw(r)~exp(-(rsw/r)nsw) allows us to describe the potential as a multipole expansion representation in the limit of large r(-->?). In the application to methane, first the representations are fitted to data from high level ab initio calculations using multireference configuration interaction techniques. Additional conditions which help to improve the description of experimental data are considered during the fit. Typically, these conditions involve some parameters or parameter groups and refer to the equilibrium geometry and harmonic force field. Other constraints apply to the energies of dissociation channels. We describe the model potentials METPOT 1 to METPOT 4 in the present work.

Marquardt, Roberto; Quack, Martin

1998-12-01

351

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

PubMed

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

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

2010-12-01

352

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

PubMed

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

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

2014-01-01

353

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

PubMed

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

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

354

Single particle calculations for a Woods Saxon potential with triaxial deformations, and large Cartesian oscillator basis (new version code)  

NASA Astrophysics Data System (ADS)

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.

Mohammed-Azizi, B.; Medjadi, D. E.

2007-05-01

355

Differences in the efficiency of pattern encoding in relation to autistic-like traits: an event-related potential study.  

PubMed

We examined the effects of complexity on the efficiency of pattern encoding in the general population differing on autism-spectrum quotient (AQ) scores. We compared brain activity (electroencephalography) during a same-different task for High and Low AQ groups. The task was composed of identical comparison and categorical comparison (CC) conditions that presented simple or complex patterns. In the CC condition, the Low AQ showed large P3b amplitudes with simple patterns than with complex patterns, whereas the High AQ showed the same amplitude levels for these patterns. These indicate that, similar to simple patterns, complex patterns are efficiently encoded in the High AQ. Moreover, the High AQ had no impairment in the global pattern encoding compared with the Low AQ. PMID:24898909

Takahashi, Junichi; Yasunaga, Daichi; Gyoba, Jiro

2014-11-01

356

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

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

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

2014-01-01

357

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 Central

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 Points The 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 volumes Stretching of the main leg muscle groups for only 15 s has no effect on ROM of elite gymnasts In 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

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

2014-01-01

358

Rapid Maturation of Edge Sensor Technology and Potential Application in Large Space Telescopes with Segmented Primary Mirrors  

NASA Technical Reports Server (NTRS)

This paper explores the history and results of the last two year's efforts to transition inductive edge sensor technology from Technology Readiness Level 2 to Technology Readiness Level 6. Both technical and programmatic challenges were overcome in the design, fabrication, test, and installation of over a thousand sensors making up the Segment Alignment Maintenance System (SAMs) for the 91 segment, 9.2-meter. Hobby Eberly Telescope (HET). The integration of these sensors with the control system will be discussed along with serendipitous leverage they provided for both initialization alignment and operational maintenance. The experience gained important insights into the fundamental motion mechanics of large segmented mirrors, the relative importance of the variance sources of misalignment errors, the efficient conduct of a program to mature the technology to the higher levels. Unanticipated factors required the team to develop new implementation strategies for the edge sensor information which enabled major segmented mirror controller design simplifications. The resulting increase in the science efficiency of HET will be shown. Finally, the on-going effort to complete the maturation of inductive edge sensor by delivering space qualified versions for future IR (infrared radiation) space telescopes.

Montgomery, Edward E., IV; Smith, W. Scott (Technical Monitor)

2002-01-01

359

The potential of large germanium detector arrays for solar-axion searches utilizing the axio-electric effect for detection  

E-print Network

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.

F. T. Avignone III

2008-10-27

360

Influence of Transepithelial Potential Difference on the Sodium Uptake at the Outer Surface of the Isolated Frog Skin  

PubMed Central

The unidirectional uptake of sodium across the outer surface of the isolated frog skin (J12Na) was measured in the presence of transepithelial potential difference (??) ranging from +100 to -100 mV. With a sodium concentration of 115 mM in the bathing solutions J12Na increases significantly when the spontaneous ?? is reduced to zero by short-circuiting the skin. With an Na concentration of 6 mM a progressive increase J12Na can be observed when ?? is decreased in several steps from +100 to -100 mV (serosal side positive and negative, respectively). The observed change J12Na amounts to a fraction only of that predicted from the shift in ??. The results suggest that under open circuit conditions the potential step across the outside surface is at most one half of ?? and that the resistance across the outside and inside barrier of the skin is ohmic. This is in agreement with measurements of intracellular potentials in the frog skin and with resistance measurements carried out in the toad skin. The data strongly support the view that the saturating component of J? proceeds via a charged carrier system. Exposure to negative values of ?? of 50 mV or more for times of 24 min or more result in a marked reduction of J12Na which shows only partial or no reversibility. PMID:4540958

Biber, Thomas U. L.; Sanders, Molly L.

1973-01-01

361

Ozone formation potentials of organic compounds from different emission sources in the South Coast Air Basin of California  

NASA Astrophysics Data System (ADS)

Different organic compounds exhibit different propensities for ozone formation. Two approaches were used to study the ozone formation potentials or source reactivities of different anthropogenic organic compounds emission categories in California's South Coast Air Basin (SoCAB). The first approach was based on the combination of total organic gases (TOG) emission speciation profiles and the maximum incremental reactivity (MIR) scale of organic species. The second approach quantified ozone impacts from different emission sources by performing 3-dimensional air quality model sensitivity analysis involving increased TOG emissions from particular sources. The source reactivities derived from these two approaches agree reasonably well for 58 anthropogenic organic compounds emission categories in the SoCAB. Both approaches identify TOG emissions from mobile sources as having the highest reactivity. Source reactivities from both approaches were also combined with TOG emissions from each source category to produce a 2005 reactivity-based anthropogenic TOG emission inventory for the SoCAB. The top five reactivity-based anthropogenic TOG emission sources in the SoCAB during 2005 were: light-duty passenger cars, off-road equipment, consumer products, light-duty trucks category 2 (i.e., 3751-5750 lb), and recreational boats. This is in contrast to the mass-based TOG emission inventory, which indicates that livestock waste and composting emission categories were two of the five largest mass-based anthropogenic TOG emission sources. The reactivity-based TOG emission inventory is an important addition to the mass-based TOG emission inventory because it represents the ozone formation potentials from emission sources and can be used to assist in determining targeted sources for developing organic compounds reduction policies.

Chen, Jianjun; Luo, Dongmin

2012-08-01

362

Estimating the Percentage of the Population With Abnormally Low Scores (or Abnormally Large Score Differences) on Standardized  

E-print Network

differences) is fundamental in interpreting the results of a neuropsychological assessment (Crawford, 2004 Differences) on Standardized Neuropsychological Test Batteries: A Generic Method With Applications John R of Aberdeen Information on the rarity or abnormality of an individual's test scores (or test score differences

Crawford, John R.

363

A 28,000 Years Old Cro-Magnon mtDNA Sequence Differs from All Potentially Contaminating Modern Sequences  

PubMed Central

Background DNA sequences from ancient speciments may in fact result from undetected contamination of the ancient specimens by modern DNA, and the problem is particularly challenging in studies of human fossils. Doubts on the authenticity of the available sequences have so far hampered genetic comparisons between anatomically archaic (Neandertal) and early modern (Cro-Magnoid) Europeans. Methodology/Principal Findings We typed the mitochondrial DNA (mtDNA) hypervariable region I in a 28,000 years old Cro-Magnoid individual from the Paglicci cave, in Italy (Paglicci 23) and in all the people who had contact with the sample since its discovery in 2003. The Paglicci 23 sequence, determined through the analysis of 152 clones, is the Cambridge reference sequence, and cannot possibly reflect contamination because it differs from all potentially contaminating modern sequences. Conclusions/Significance: The Paglicci 23 individual carried a mtDNA sequence that is still common in Europe, and which radically differs from those of the almost contemporary Neandertals, demonstrating a genealogical continuity across 28,000 years, from Cro-Magnoid to modern Europeans. Because all potential sources of modern DNA contamination are known, the Paglicci 23 sample will offer a unique opportunity to get insight for the first time into the nuclear genes of early modern Europeans. PMID:18628960

Caramelli, David; Milani, Lucio; Vai, Stefania; Modi, Alessandra; Pecchioli, Elena; Girardi, Matteo; Pilli, Elena; Lari, Martina; Lippi, Barbara; Ronchitelli, Annamaria; Mallegni, Francesco; Casoli, Antonella; Bertorelle, Giorgio; Barbujani, Guido

2008-01-01

364

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

PubMed Central

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

Haye, Pilar A.; Segovia, Nicolas I.; Munoz-Herrera, Natalia C.; Galvez, Francisca E.; Martinez, Andrea; Meynard, Andres; Pardo-Gandarillas, Maria C.; Poulin, Elie; Faugeron, Sylvain

2014-01-01

365

[Changes in components of the auditory long-latency evoked potentials at different stages of the slow-wave sleep].  

PubMed

In accordance with the present views, during sleep, analysis of external stimuli continues at the subconscious level, because the need to estimate the biological significance of external stimuli in order to maintain a flexible contact of a sleeping subject with the environment persists during sleep. It is known that new components of the auditory evoked potentials (AEP) appear as sleep deepens. However, the common procedure of analysis of event-related potentials averaged for a group of subjects has some drawbacks because of the interindividual variability of the event-related potentials. Therefore, an additional analysis of the interindividual variability of the AEP shape and component structure can simplify the detection of individual components of group-averaged AEP at different stages of the slow-wave sleep. The AEPs were recorded in healthy volunteers (n = 26) during falling asleep in the evening from eight EEG derivations (F3, F4, C3, C4, P3, P4, O1, O2) in reference to a linked mastoid electrode. Computer-generated sound stimuli (50 ms-pulses with the frequency of 1000 Hz, 60 dB HL) were presented binaurally through earphones with interstimulus intervals of 20-40 s. Selective summation of AEPs for all the subjects was performed for each stage of the slow-wave sleep individually for each of the eight derivations. It was shown that the account made for interindividual variability of the AEP shape facilitated the identification of individual components of the group-averaged AEP typical of wakefulness (P1, N1, P300) and those which appeared during sleep onset and at different stages of the slow-wave sleep (P2, N350, P450, N550, N900). PMID:15828419

Dorokhov, V B; Verbitskaia, Iu S

2005-01-01

366

Sex differences and effects of neonatal aromatase inhibition on masculine and feminine copulatory potentials in prairie voles.  

PubMed

Copulatory behaviors in most rodents are highly sexually dimorphic, even when circulating hormones are equated between the sexes. Prairie voles (Microtus ochrogaster) are monomorphic in their display of some social behaviors, including partner preferences and parenting, but differences between the sexes in their masculine and feminine copulatory behavior potentials have not been studied in detail. Furthermore, the role of neonatal aromatization of testosterone to estradiol on the development of prairie vole sexual behavior potentials or their brain is unknown. To address these issues, prairie vole pups were injected daily for the first week after birth with 0.5 mg of the aromatase inhibitor 1,4,6-androstatriene-3,17-dione (ATD) or oil. Masculine and feminine copulatory behaviors in response to testosterone or estradiol were later examined in both sexes. Males and females showed high mounting and thrusting in response to testosterone, but only males reliably showed ejaculatory behavior. Conversely, males never showed feminine copulatory behaviors in response to estradiol. Sex differences in these behaviors were not affected by neonatal ATD, but ATD-treated females received fewer mounts and thrusts than controls, possibly indicating reduced attractiveness to males. In other groups of subjects, neonatal ATD demasculinized males' tyrosine hydroxylase expression in the anteroventral periventricular preoptic area, and estrogen receptor alpha expression in the medial preoptic area. Thus, although sexual behavior in both sexes of prairie voles is highly masculinized, aromatase during neonatal life is necessary only for females' femininity. Furthermore, copulatory behavior potentials and at least some aspects of brain development in male prairie voles are dissociable by their requirement for neonatal aromatase. PMID:18378236

Northcutt, Katharine V; Lonstein, Joseph S

2008-06-01

367

The Appeal of Vouchers for Failing Large City School Districts: Voting in Congress on Two Very Different Voucher Proposals  

ERIC Educational Resources Information Center

Virtually all voucher programs in the United States limit vouchers to a large struggling city such as Cleveland, Milwaukee, or the District of Columbia. This study examines the votes cast by 188 Republicans in the U.S. House of Representatives who cast votes on (a) a nationwide voucher plan in 2001 and (b) a 2003 proposal for vouchers for DC. This…

Kenny, Lawrence W.

2010-01-01

368

A Microsatellite Linkage Map of Rainbow Trout (Oncorhynchus mykiss) Characterized by Large Sex-Specific Differences in Recombination Rates  

Microsoft Academic Search

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

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

369

Differences in regional substitution pattern in the human genome created patterns of large-scale variations of base composition known as genomic isochores. Different regions of the human  

E-print Network

in repetitive elements. Comparing individual copies of repetitive elements with the ancestral master sequence of the repetitive element. Comparing substitution patterns from differently old repetitive elements we are also able that simultaneously estimates the substitution frequencies corrected for multiple hits of the same base given a pair

Spang, Rainer

370

The potential of dental stem cells differentiating into neurogenic cell lineage after cultivation in different modes in vitro.  

PubMed

Abstract Trauma or degenerative diseases of the central nervous system (CNS) cause the loss of neurons or glial cells. Stem cell transplantation has become a vital strategy for CNS regeneration. It is necessary to effectively induce nonneurogenic stem cells to differentiate into neurogenic cell lineages because of the limited source of neurogenic stem cells, relatively difficult cultivation, and ethical issues. Previous studies have found that dental stem cells can be used for transplantation therapy. The aim of this study was to explore a better inductive mode and time point for dental stem cells to differentiate into neural-like cells and evaluate a better candidate cell. In this study, dental follicle stem cells (DFSCs), dental papilla stem cells (DPSCs), and stem cells from apical papilla (SCAPs) were cultivated in five different modes. The proliferation ability, morphology, and expression of neural marker genes were analyzed. Results showed that DFSCs showed a higher proliferation potential. The proliferation was decreased after cultivation in chemical inductive medium as cultivation modes 3 and 5. The cells could present neural-like cell morphology after cultivation with human epidermal growth factor (EGF) and fibroblast growth factor-basic (bFGF) as cultivation modes 4 and 5. The vast majority of DFSCs gene expression levels in mode 4 on the third day was upregulated significantly. In conclusion, our data suggested that different dental stem cells exhibited different neural differentiation potentials. DFSCs might be the better candidate cell type. Furthermore, cultivation mode 4 and timing of the third day may promote differentiation into neurogenic cell lineages more effectively before transplantation to treat neurological diseases. PMID:25072651

Yang, Chao; Sun, Liang; Li, Xinghan; Xie, Li; Yu, Mei; Feng, Lian; Jiang, Zongting; Guo, Weihua; Tian, Weidong

2014-10-01

371

Strong habitat preference of a tropical rain forest tree does not imply large differences in population dynamics across habitats  

Microsoft Academic Search

Summary 1 Many tropical forest tree species show habitat preference, commonly revealed by differences in abundance among habitats. Very little is known about differences in individual performance and population dynamics across habitats. 2 We analysed habitat-specific performance and demography of Scaphium borneense , a tropical rain forest tree with strong habitat preference in a 52-ha plot at Lambir Hills, Malay-

TOSHIHIRO YAMADA; PIETER A. ZUIDEMA; AKIRA ITOH; TAKUO YAMAKURA; TATSUHIRO OHKUBO; MAMORU KANZAKI; SYLVESTER TAN; PETER S. ASHTON

2007-01-01

372

Morphological and Metabolic Changes Associated with Large Differences in Daily Food Intake in Crossed-Intestines Rats  

Microsoft Academic Search

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

Henry S Koopmans; Thomas J McDonald; Mario Digirolamo

1997-01-01

373

Large-Eddy Simulation of the Stable Atmospheric Boundary Layer using Dynamic Models with Different Averaging Schemes  

Microsoft Academic Search

Large-eddy simulation (LES) of a stable atmospheric boundary layer is performed using recently developed dynamic subgrid-scale\\u000a (SGS) models. These models not only calculate the Smagorinsky coefficient and SGS Prandtl number dynamically based on the\\u000a smallest resolved motions in the flow, they also allow for scale dependence of those coefficients. This dynamic calculation\\u000a requires statistical averaging for numerical stability. Here, we

Rob Stoll; Fernando Porté-Agel

2008-01-01

374

Applying different methods to evaluate the freshness of large yellow croacker (Pseudosciaena crocea) fillets during chilled storage.  

PubMed

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

Zhao, Jin; Li, Jianrong; Wang, Jinlin; Lv, Weijin

2012-11-14

375

Differences in visuo-motor control in skilled vs. novice martial arts athletes during sustained and transient attention tasks: a motor-related cortical potential study.  

PubMed

Cognitive and motor processes are essential for optimal athletic performance. Individuals trained in different skills and sports may have specialized cognitive abilities and motor strategies related to the characteristics of the activity and the effects of training and expertise. Most studies have investigated differences in motor-related cortical potential (MRCP) during self-paced tasks in athletes but not in stimulus-related tasks. The aim of the present study was to identify the differences in performance and MRCP between skilled and novice martial arts athletes during two different types of tasks: a sustained attention task and a transient attention task. Behavioral and electrophysiological data from twenty-two martial arts athletes were obtained while they performed a continuous performance task (CPT) to measure sustained attention and a cued continuous performance task (c-CPT) to measure transient attention. MRCP components were analyzed and compared between groups. Electrophysiological data in the CPT task indicated larger prefrontal positive activity and greater posterior negativity distribution prior to a motor response in the skilled athletes, while novices showed a significantly larger response-related P3 after a motor response in centro-parietal areas. A different effect occurred in the c-CPT task in which the novice athletes showed strong prefrontal positive activity before a motor response and a large response-related P3, while in skilled athletes, the prefrontal activity was absent. We propose that during the CPT, skilled athletes were able to allocate two different but related processes simultaneously according to CPT demand, which requires controlled attention and controlled motor responses. On the other hand, in the c-CPT, skilled athletes showed better cue facilitation, which permitted a major economy of resources and "automatic" or less controlled responses to relevant stimuli. In conclusion, the present data suggest that motor expertise enhances neural flexibility and allows better adaptation of cognitive control to the requested task. PMID:24621480

Sanchez-Lopez, Javier; Fernandez, Thalia; Silva-Pereyra, Juan; Martinez Mesa, Juan A; Di Russo, Francesco

2014-01-01

376

Differences in Visuo-Motor Control in Skilled vs. Novice Martial Arts Athletes during Sustained and Transient Attention Tasks: A Motor-Related Cortical Potential Study  

PubMed Central

Cognitive and motor processes are essential for optimal athletic performance. Individuals trained in different skills and sports may have specialized cognitive abilities and motor strategies related to the characteristics of the activity and the effects of training and expertise. Most studies have investigated differences in motor-related cortical potential (MRCP) during self-paced tasks in athletes but not in stimulus-related tasks. The aim of the present study was to identify the differences in performance and MRCP between skilled and novice martial arts athletes during two different types of tasks: a sustained attention task and a transient attention task. Behavioral and electrophysiological data from twenty-two martial arts athletes were obtained while they performed a continuous performance task (CPT) to measure sustained attention and a cued continuous performance task (c-CPT) to measure transient attention. MRCP components were analyzed and compared between groups. Electrophysiological data in the CPT task indicated larger prefrontal positive activity and greater posterior negativity distribution prior to a motor response in the skilled athletes, while novices showed a significantly larger response-related P3 after a motor response in centro-parietal areas. A different effect occurred in the c-CPT task in which the novice athletes showed strong prefrontal positive activity before a motor response and a large response-related P3, while in skilled athletes, the prefrontal activity was absent. We propose that during the CPT, skilled athletes were able to allocate two different but related processes simultaneously according to CPT demand, which requires controlled attention and controlled motor responses. On the other hand, in the c-CPT, skilled athletes showed better cue facilitation, which permitted a major economy of resources and “automatic” or less controlled responses to relevant stimuli. In conclusion, the present data suggest that motor expertise enhances neural flexibility and allows better adaptation of cognitive control to the requested task. PMID:24621480

Sanchez-Lopez, Javier; Fernandez, Thalia; Silva-Pereyra, Juan; Martinez Mesa, Juan A.; Di Russo, Francesco

2014-01-01

377

Proanthocyanidin composition and antioxidant potential of the stem winemaking byproducts from 10 different grape varieties (Vitis vinifera L.).  

PubMed

Stem byproducts from 10 different grape (Vitis vinifera L.) varieties were evaluated in terms of their total phenolic and total proanthocyanidin contents, flavan-3-ol and proanthocyanidin profiles, and antioxidant capacity measured by ABTS, CUPRAC, FRAP, and ORAC assays, with a view to the recovery of their natural bioactive compounds. Stems from Callet, Syrah, Premsal Blanc, Parellada, and Manto Negro varieties yielded the highest total phenolic and total proanthocyanidin contents and showed the greatest antioxidant capacities, whereas Chardonnay and Merlot stems presented the lowest values. Varieties differed significantly (p<0.05) with regard to both the phenolic composition and antioxidant capacity of their stems. However, no significant differences (p>0.05) were observed when stems from red and white varieties were considered separately. For the 10 grape varieties investigated, this is the first study presenting a detailed description of their stem flavan-3-ol composition determined by HPLC-UV-fluo. All of the analyses confirmed the stem byproducts as a potential polyphenol-rich source, especially promising in the case of the Callet variety. PMID:23101762

González-Centeno, María Reyes; Jourdes, Michael; Femenia, Antoni; Simal, Susana; Rosselló, Carmen; Teissedre, Pierre-Louis

2012-12-01

378

Surface-Induced Dissociation Shows Potential to be More Informative than Collision-Induced Dissociation for Structural Studies of Large Systems  

PubMed Central

The ability to preserve non-covalent, macromolecular assemblies intact in the gas-phase has paved the way for mass spectrometry to characterize ions of increasing size and become a powerful tool in the field of structural biology. Tandem mass spectrometry experiments have the potential to expand the capabilities of this technique through the gas-phase dissociation of macromolecular complexes, but collisions with small gas atoms currently provide very limited fragmentation. One alternative for dissociating large ions is to collide them into a surface, a more massive target. Here, we demonstrate the ability and benefit of fragmenting large protein complexes and inorganic salt clusters by surface-induced dissociation (SID). SID provides more extensive fragmentation of these systems and shows promise as an activation method for ions of increasing size. PMID:18598898

Wysocki, Vicki H.; Jones, Christopher M.; Galhena, Asiri S.; Blackwell, Anne E.

2008-01-01

379

2D potential measurements by applying automatic beam adjustment system to heavy ion beam probe diagnostic on the Large Helical Devicea)  

NASA Astrophysics Data System (ADS)

Two-dimensional potential profiles in the Large Helical Device (LHD) were measured with heavy ion beam probe (HIBP). To measure the two-dimensional profile, the probe beam energy has to be changed. However, this task is not easy, because the beam transport line of LHD-HIBP system is very long (˜20 m), and the required beam adjustment consumes much time. To reduce the probe beam energy adjustment time, an automatic beam adjustment system has been developed. Using this system, required time to change the probe beam energy is dramatically reduced, such that two-dimensional potential profiles were able to be successfully measured with HIBP by changing the probe beam energy shot to shot.

Shimizu, A.; Ido, T.; Kurachi, M.; Makino, R.; Nishiura, M.; Kato, S.; Nishizawa, A.; Hamada, Y.

2014-11-01

380

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

PubMed

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

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

2014-08-01

381

Echinococcus multilocularis in Belgium: prevalence in red foxes (Vulpes vulpes) and in different species of potential intermediate hosts.  

PubMed

Echinococcus multilocularis causes a rare but potentially lethal zoonotic infection in humans. This tapeworm is known to be endemic in foxes in several countries of Western and Central Europe. In Western Europe, the common vole (Microtus arvalis) and the water vole (Arvicola terrestris) are considered to be the most important intermediate host species of this cestode whereas the red fox is by far the most important final host. The purpose of this study was to provide data on the prevalences in Wallonia (Southern part of Belgium) both in the red fox and in different potential intermediate hosts. A total of 990 red foxes were examined between January 2003 and December 2004 for the presence of E. multilocularis. The average prevalence was 24.55% (22.38-27.87). Out of 1249 rodents or insectivores belonging to the species Apodemus sylvaticus, Arvicola terrestris, Clethrionomys glareolus, Microtus arvalis, Microtus agrestris and Sorex araneus, only one M. arvalis (out of 914-0.11% (0.003-0.61) and one C. glareolus (out of 23-4.3% (0.1-21.9) were found to be infected. However, the muskrat (Ondatra zibethicus) seems to be a good intermediate host as 11.18% (9.72-12.76) of the animals (n=1718) were found to be infected. A positive correlation was found between the prevalences in foxes and in muskrats in each of the different geological regions. This study indicates that the muskrat is highly sensitive to this zoonotic tapeworm and could perhaps represent a good bioindicator when studying the epidemiology of this parasitic infection in Belgium and in other countries where the muskrat is present. PMID:18164551

Hanosset, R; Saegerman, C; Adant, S; Massart, L; Losson, B

2008-02-14

382

Differences between brain mass and body weight scaling to height: potential mechanism of reduced mass-specific resting energy expenditure of taller adults  

PubMed Central

Adult resting energy expenditure (REE) scales as height?1.5, whereas body weight (BW) scales as height?2. Mass-specific REE (i.e., REE/BW) is thus lower in tall subjects compared with their shorter counterparts, the mechanism of which is unknown. We evaluated the hypothesis that high-metabolic-rate brain mass scales to height with a power significantly less than that of BW, a theory that if valid would provide a potential mechanism for height-related REE effects. The hypothesis was tested by measuring brain mass on a large (n = 372) postmortem sample of Thai men. Since brain mass-body size relations may be influenced by age, the hypothesis was secondarily explored in Thai men age ?45 yr (n = 299) and with brain magnetic resonance imaging (MRI) studies in Korean men (n = 30) age ?20<30 yr. The scaling of large body compartments was examined in a third group of Asian men living in New York (NY, n = 28) with MRI and dual-energy X-ray absorptiometry. Brain mass scaled to height with a power (mean ± SEE; 0.46 ± 0.13) significantly smaller (P < 0.001) than that of BW scaled to height (2.36 ± 0.19) in the whole group of Thai men; brain mass/BW scaled negatively to height (?1.94 ± 0.20, P < 0.001). Similar results were observed in younger Thai men, and results for brain mass/BW vs. height were directionally the same (P = 0.09) in Korean men. Skeletal muscle and bone scaled to height with powers similar to that of BW (i.e., ?2–3) in the NY Asian men. Models developed using REE estimates in Thai men suggest that brain accounts for most of the REE/BW height dependency. Tall and short men thus differ in relative brain mass, but the proportions of BW as large compartments appear independent of height, observations that provide a potential mechanistic basis for related differences in REE and that have implications for the study of adult energy requirements. PMID:19008483

Heymsfield, Steven B.; Chirachariyavej, Thamrong; Rhyu, Im Joo; Roongpisuthipong, Chulaporn; Heo, Moonseong; Pietrobelli, Angelo

2009-01-01

383

Differences between brain mass and body weight scaling to height: potential mechanism of reduced mass-specific resting energy expenditure of taller adults.  

PubMed

Adult resting energy expenditure (REE) scales as height( approximately 1.5), whereas body weight (BW) scales as height( approximately 2). Mass-specific REE (i.e., REE/BW) is thus lower in tall subjects compared with their shorter counterparts, the mechanism of which is unknown. We evaluated the hypothesis that high-metabolic-rate brain mass scales to height with a power significantly less than that of BW, a theory that if valid would provide a potential mechanism for height-related REE effects. The hypothesis was tested by measuring brain mass on a large (n = 372) postmortem sample of Thai men. Since brain mass-body size relations may be influenced by age, the hypothesis was secondarily explored in Thai men age < or =45 yr (n = 299) and with brain magnetic resonance imaging (MRI) studies in Korean men (n = 30) age > or =20<30 yr. The scaling of large body compartments was examined in a third group of Asian men living in New York (NY, n = 28) with MRI and dual-energy X-ray absorptiometry. Brain mass scaled to height with a power (mean +/- SEE; 0.46 +/- 0.13) significantly smaller (P < 0.001) than that of BW scaled to height (2.36 +/- 0.19) in the whole group of Thai men; brain mass/BW scaled negatively to height (-1.94 +/- 0.20, P < 0.001). Similar results were observed in younger Thai men, and results for brain mass/BW vs. height were directionally the same (P = 0.09) in Korean men. Skeletal muscle and bone scaled to height with powers similar to that of BW (i.e., approximately 2-3) in the NY Asian men. Models developed using REE estimates in Thai men suggest that brain accounts for most of the REE/BW height dependency. Tall and short men thus differ in relative brain mass, but the proportions of BW as large compartments appear independent of height, observations that provide a potential mechanistic basis for related differences in REE and that have implications for the study of adult energy requirements. PMID:19008483

Heymsfield, Steven B; Chirachariyavej, Thamrong; Rhyu, Im Joo; Roongpisuthipong, Chulaporn; Heo, Moonseong; Pietrobelli, Angelo

2009-01-01

384

Application of augmented-Lagrangian methods in meteorology: Comparison of different conjugate-gradient codes for large-scale minimization  

NASA Technical Reports Server (NTRS)

A Lagrange multiplier method using techniques developed by Bertsekas (1982) was applied to solving the problem of enforcing simultaneous conservation of the nonlinear integral invariants of the shallow water equations on a limited area domain. This application of nonlinear constrained optimization is of the large dimensional type and the conjugate gradient method was found to be the only computationally viable method for the unconstrained minimization. Several conjugate-gradient codes were tested and compared for increasing accuracy requirements. Robustness and computational efficiency were the principal criteria.

Navon, I. M.

1984-01-01

385

Sex differences in visual evoked potentials in school-age children: what is the evidence beyond the checkerboard?  

PubMed

Visual evoked potentials (VEPs) are known to be influenced by several biological variables, including sex. In adult populations studies using conventional high-contrast checkerboard have shown that females display larger amplitudes and shorter latencies than males. To date, few studies have been conducted in children; the available data suggests that girls display significantly larger amplitudes than boys but the effect on latency is absent or negligible. We investigated sex-related VEP differences in 149 school-age (11.3 ± 0.6 years) children from Northern Quebec using several VEP protocols: achromatic pattern-reversal VEPs at high (95%) and low contrast (30%, 12% and 4%), as well as motion-onset VEPs and isoluminant pattern-reversal VEPs. Girls showed significantly larger amplitudes in achromatic VEPs for most of the contrast levels as well as in N2 response to motion-onset. No significant difference was found regarding the amplitude of isoluminant VEPs. In addition, girls showed shorter latencies for the achromatic N75 and a trend (p<0.1) for the P100, regardless of the contrast level. Interestingly, this latency effect appeared mostly due to head size, not sex. No differences in latency were found for motion or isoluminant responses. Overall, these findings show that sex-related differences are present in children mostly in VEP amplitude not only for high contrast achromatic pattern-reversal but also for low contrast levels and motion-onset VEPs, suggesting that sex affects VEP responses in a general fashion. PMID:23501018

Dion, Laurie-Anne; Muckle, Gina; Bastien, Célyne; Jacobson, Sandra W; Jacobson, Joseph L; Saint-Amour, Dave

2013-05-01

386

Seasonal differences of vertical-transport efficiency in the tropical tropopause layer: On the interplay between tropical deep convection, large-scale vertical ascent, and horizontal circulations  

NASA Astrophysics Data System (ADS)

Winter-summer differences in the transport of air from the boundary layer to the lower stratosphere at low latitudes are investigated with ensembles of back trajectory calculations that track parcels from the 380 K isentropic surface to their convective detrainment in the tropical tropopause layer (TTL) during the winter of 2006-2007 and summer of 2007. Horizontal displacements for the trajectories are calculated from reanalysis data; potential temperature displacements are calculated from radiative heating rates derived from observed cloud, water vapor, ozone, and temperature variations; and the locations' convective detrainments are determined by satellite observations of convective clouds. Weaker upwelling in the TTL during boreal summer compared with that of winter both slows the ascent through the TTL and raises the height threshold that convective detrainment must surpass in order for ascent to occur, restricting the injection of new air into the stratosphere during summer. In addition, anticyclonic circulations associated with convective activity contribute to vertical transport in the TTL by guiding detrained air parcels through regions with the strongest upwelling. These features combine to make monsoon-related convection over the Indian subcontinent the dominant source of new air during summer. In contrast, winter sources are spread over the southern continents and the western Pacific Ocean. These seasonal differences imply that air entering the tropical stratosphere during summer is older but might nevertheless be more polluted than air entering during winter. While poor data sampling in the TTL makes it difficult to validate our results, they are bolstered by favorable comparisons with previous studies of the TTL, by sensitivity tests that reveal important dynamical influences on surface-to-stratospheric transport, and by the robustness of dynamical interactions that systematically associate deep convection with anticyclonic circulations and strong radiative heating in the TTL. Sensitivity experiments suggest that the aforementioned seasonal differences are sensitive to strong "large-scale" (on global space scales and seasonal time scales) perturbations. In particular, uncertainties in the vertical motion fields constrain our ability to draw definitive conclusions. However, trajectory statistics are not sensitive to small-scale perturbations, with the encouraging implication that our results are primarily associated with those features of the circulation that are the most likely to be robust.

Bergman, John W.; Jensen, Eric J.; Pfister, Leonhard; Yang, Qiong

2012-03-01

387

Prevalence of Trachoma in Unity State, South Sudan: Results from a Large-Scale Population-Based Survey and Potential Implications for Further Surveys  

Microsoft Academic Search

BackgroundLarge parts of South Sudan are thought to be trachoma-endemic but baseline data are limited. This study aimed to estimate prevalence for planning trachoma interventions in Unity State, to identify risk factors and to investigate the effect of different sampling approaches on study conclusions.Methods and FindingsThe survey area was defined as one domain of eight counties in Unity State. Across

Tansy Edwards; Jennifer Smith; Hugh J. W. Sturrock; Lucia W. Kur; Anthony Sabasio; Timothy P. Finn; Mounir Lado; Danny Haddad; Jan H. Kolaczinski

2012-01-01

388

Different environmental conditions, different results: the role of controlled environmental stress on grape quality potential and the way to monitor it  

Microsoft Academic Search

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),

C. van Leeuwen; O. Trégoat; X. Choné; J.-P. Gaudillère; D. Pernet

389

Large-scale, high-resolution multielectrode-array recording depicts functional network differences of cortical and hippocampal cultures.  

PubMed

Understanding the detailed circuitry of functioning neuronal networks is one of the major goals of neuroscience. Recent improvements in neuronal recording techniques have made it possible to record the spiking activity from hundreds of neurons simultaneously with sub-millisecond temporal resolution. Here we used a 512-channel multielectrode array system to record the activity from hundreds of neurons in organotypic cultures of cortico-hippocampal brain slices from mice. To probe the network structure, we employed a wavelet transform of the cross-correlogram to categorize the functional connectivity in different frequency ranges. With this method we directly compare, for the first time, in any preparation, the neuronal network structures of cortex and hippocampus, on the scale of hundreds of neurons, with sub-millisecond time resolution. Among the three frequency ranges that we investigated, the lower two frequency ranges (gamma (30-80 Hz) and beta (12-30 Hz) range) showed similar network structure between cortex and hippocampus, but there were many significant differences between these structures in the high frequency range (100-1000 Hz). The high frequency networks in cortex showed short tailed degree-distributions, shorter decay length of connectivity density, smaller clustering coefficients, and positive assortativity. Our results suggest that our method can characterize frequency dependent differences of network architecture from different brain regions. Crucially, because these differences between brain regions require millisecond temporal scales to be observed and characterized, these results underscore the importance of high temporal resolution recordings for the understanding of functional networks in neuronal systems. PMID:25126851

Ito, Shinya; Yeh, Fang-Chin; Hiolski, Emma; Rydygier, Przemyslaw; Gunning, Deborah E; Hottowy, Pawel; Timme, Nicholas; Litke, Alan M; Beggs, John M

2014-01-01

390

The Complete Genome and Proteome of Laribacter hongkongensis Reveal Potential Mechanisms for Adaptations to Different Temperatures and Habitats  

PubMed Central

Laribacter hongkongensis is a newly discovered Gram-negative bacillus of the Neisseriaceae family associated with freshwater fish–borne gastroenteritis and traveler's diarrhea. The complete genome sequence of L. hongkongensis HLHK9, recovered from an immunocompetent patient with severe gastroenteritis, consists of a 3,169-kb chromosome with G+C content of 62.35%. Genome analysis reveals different mechanisms potentially important for its adaptation to diverse habitats of human and freshwater fish intestines and freshwater environments. The gene contents support its phenotypic properties and suggest that amino acids and fatty acids can be used as carbon sources. The extensive variety of transporters, including multidrug efflux and heavy metal transporters as well as genes involved in chemotaxis, may enable L. hongkongensis to survive in different environmental niches. Genes encoding urease, bile salts efflux pump, adhesin, catalase, superoxide dismutase, and other putative virulence factors—such as hemolysins, RTX toxins, patatin-like proteins, phospholipase A1, and collagenases—are present. Proteomes of L. hongkongensis HLHK9 cultured at 37°C (human body temperature) and 20°C (freshwater habitat temperature) showed differential gene expression, including two homologous copies of argB, argB-20, and argB-37, which encode two isoenzymes of N-acetyl-L-glutamate kinase (NAGK)—NAGK-20 and NAGK-37—in the arginine biosynthesis pathway. NAGK-20 showed higher expression at 20°C, whereas NAGK-37 showed higher expression at 37°C. NAGK-20 also had a lower optimal temperature for enzymatic activities and was inhibited by arginine probably as negative-feedback control. Similar duplicated copies of argB are also observed in bacteria from hot springs such as Thermus thermophilus, Deinococcus geothermalis, Deinococcus radiodurans, and Roseiflexus castenholzii, suggesting that similar mechanisms for temperature adaptation may be employed by other bacteria. Genome and proteome analysis of L. hongkongensis revealed novel mechanisms for adaptations to survival at different temperatures and habitats. PMID:19283063

Curreem, Shirly O. T.; Tsang, Alan K. L.; Fan, Rachel Y. Y.; Wong, Gilman K. M.; Huang, Yi; Loman, Nicholas J.; Snyder, Lori A. S.; Cai, James J.; Huang, Jian-Dong; Mak, William; Pallen, Mark J.; Lok, Si; Yuen, Kwok-Yung

2009-01-01

391

An Evaluation of the Environmental Impact of Different Commercial Supermarket Refrigeration Systems Using Low Global Warming Potential Refrigerants  

SciTech Connect

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 us