Sample records for small direct effect

  1. Directed enzyme evolution via small and effective

    E-print Network

    Cai, Long

    for preparing such libraries, using serum paraoxonase (PON1). An optimized GFP variant fused to PON1 reported with serum paraoxonase (PON1). Reporters such as GFP have been used in directed evolution experiments potential. Fusion of an evolved GFP variant, GFPmut3, at the C terminus of PON1 previously resulted in 20

  2. Effects of small-sided game and change-of-direction training on reactive agility and change-of-direction speed.

    PubMed

    Young, Warren; Rogers, Nathan

    2014-01-01

    The purpose of this study was to determine the effects of training change-of-direction speed and small-sided games on performance in the Planned-AFL agility test and reactive agility. Twenty-five elite-standard U-18 Australian Rules football players were randomly allocated either to a change-of-direction group or a small-sided games group. Players participated in one or two 15-min sessions per week with 11 sessions conducted over a 7-week period during the season. Tests conducted immediately before and after the training period included the Planned-AFL agility test and a video-based reactive agility test specific to Australian Rules football. The reactive agility test variables were total time, decision time and movement response time. The small-sided games group improved total time (P = 0.008, effect size = 0.93), which was entirely attributable to a very large reduction in decision time (P < 0.001, effect size = 2.32). Small-sided games produced a trivial change in movement response time as well as in the Planned-AFL agility test (P > 0.05). The change-of-direction training produced small to trivial changes in all of the test variables (P > 0.05, effect size = 0-0.2). The results suggest that small-sided games improve agility performance by enhancing the speed of decision-making rather than movement speed. The change-of-direction training was not effective for developing either change-of-direction speed as measured by the Planned-AFL test or reactive agility. PMID:24016360

  3. Effects of flow direction and thermal short-circuiting on the performance of small coaxial ground heat exchangers

    Microsoft Academic Search

    E. Zanchini; S. Lazzari; A. Priarone

    2010-01-01

    The effects of flow direction and thermal short-circuiting on the performance of small-size coaxial ground heat exchangers, currently used in Northern Italy, are studied by finite-element simulations, performed through the software package COMSOL Multiphysics 3.4 (©Comsol, Inc.). The real 2-D axisymmetric unsteady heat conduction and convection problem is considered, both for winter and for summer working conditions. The flow in

  4. Effect of Processing Pressure on Isolated Pore Formation during Controlled Directional Solidification in Small Channels

    NASA Technical Reports Server (NTRS)

    Cox, Matthew C.; Anilkumar, Amrutur V.; Grugel, RIchard N.; Lee, Chun P.

    2008-01-01

    Directional solidification experiments were performed, using succinonitrile saturated with nitrogen gas, to examine the effects of in-situ processing pressure changes on the formation growth, and evolution of an isolated, cylindrical gaseous pore. A novel solidification facility, capable of processing thin cylindrical samples (I.D. < 1.0 mm), under controlled pressure conditions, was used for the experiments. A new experimental method for growing the isolated pore from a seed bubble is introduced. The experimental results indicate that an in-situ processing pressure change will result in either a transient change in pore diameter or a complete termination of pore growth, indicating that pressure changes can be used as a control parameter to terminate bubble growth. A simple analytical model has been introduced to explain the experimental observations.

  5. Direct and indirect fishery effects on small coastal elasmobranchs in the northern Gulf of Mexico

    Microsoft Academic Search

    Travis D. Shepherd; Ransom A. Myers

    2005-01-01

    Globally, bycatch in tropical\\/subtropical shrimp trawl and longline fisheries is threatening many marine species. Here we examine the joint effects of increased mortality caused by shrimp trawling bycatch, and reduced predation caused by losses of large sharks because of longline fishing. Research surveys in the Gulf of Mexico (1972-2002) demonstrated precipitous declines in shallow water coastal elasmobranchs where shrimping effort

  6. Ebolavirus Proteins Suppress the Effects of Small Interfering RNA by Direct Interaction with the Mammalian RNA Interference Pathway ?

    PubMed Central

    Fabozzi, Giulia; Nabel, Christopher S.; Dolan, Michael A.; Sullivan, Nancy J.

    2011-01-01

    Cellular RNA interference (RNAi) provides a natural response against viral infection, but some viruses have evolved mechanisms to antagonize this form of antiviral immunity. To determine whether Ebolavirus (EBOV) counters RNAi by encoding suppressors of RNA silencing (SRSs), we screened all EBOV proteins using an RNAi assay initiated by exogenously delivered small interfering RNAs (siRNAs) against either an EBOV or a reporter gene. In addition to viral protein 35 (VP35), we found that VP30 and VP40 independently act as SRSs. Here, we present the molecular mechanisms of VP30 and VP35. VP30 interacts with Dicer independently of siRNA and with one Dicer partner, TRBP, only in the presence of siRNA. VP35 directly interacts with Dicer partners TRBP and PACT in an siRNA-independent fashion and in the absence of effects on interferon (IFN). Taken together, our findings elucidate a new mechanism of RNAi suppression that extends beyond the role of SRSs in double-stranded RNA (dsRNA) binding and IFN antagonism. The presence of three suppressors highlights the relevance of host RNAi-dependent antiviral immunity in EBOV infection and illustrates the importance of RNAi in shaping the evolution of RNA viruses. PMID:21228243

  7. Ebolavirus proteins suppress the effects of small interfering RNA by direct interaction with the mammalian RNA interference pathway.

    PubMed

    Fabozzi, Giulia; Nabel, Christopher S; Dolan, Michael A; Sullivan, Nancy J

    2011-03-01

    Cellular RNA interference (RNAi) provides a natural response against viral infection, but some viruses have evolved mechanisms to antagonize this form of antiviral immunity. To determine whether Ebolavirus (EBOV) counters RNAi by encoding suppressors of RNA silencing (SRSs), we screened all EBOV proteins using an RNAi assay initiated by exogenously delivered small interfering RNAs (siRNAs) against either an EBOV or a reporter gene. In addition to viral protein 35 (VP35), we found that VP30 and VP40 independently act as SRSs. Here, we present the molecular mechanisms of VP30 and VP35. VP30 interacts with Dicer independently of siRNA and with one Dicer partner, TRBP, only in the presence of siRNA. VP35 directly interacts with Dicer partners TRBP and PACT in an siRNA-independent fashion and in the absence of effects on interferon (IFN). Taken together, our findings elucidate a new mechanism of RNAi suppression that extends beyond the role of SRSs in double-stranded RNA (dsRNA) binding and IFN antagonism. The presence of three suppressors highlights the relevance of host RNAi-dependent antiviral immunity in EBOV infection and illustrates the importance of RNAi in shaping the evolution of RNA viruses. PMID:21228243

  8. The direct and indirect effects of a glyphosate-based herbicide and nutrients on Chironomidae (Diptera) emerging from small wetlands.

    PubMed

    Baker, Leanne F; Mudge, Joseph F; Houlahan, Jeff E; Thompson, Dean G; Kidd, Karen A

    2014-09-01

    Laboratory and mesocosm experiments have demonstrated that some glyphosate-based herbicides can have negative effects on benthic invertebrate species. Although these herbicides are among the most widely used in agriculture, there have been few multiple-stressor, natural system-based investigations of the impacts of glyphosate-based herbicides in combination with fertilizers on the emergence patterns of chironomids from wetlands. Using a replicated, split-wetland experiment, the authors examined the effects of 2 nominal concentrations (2.88?mg acid equivalents/L and 0.21?mg acid equivalents/L) of the glyphosate herbicide Roundup WeatherMax, alone or in combination with nutrient additions, on the emergence of Chironomidae (Diptera) before and after herbicide-induced damage to macrophytes. There were no direct effects of treatment on the structure of the Chironomidae community or on the overall emergence rates. However, after macrophyte cover declined as a result of herbicide application, there were statistically significant increases in emergence in all but the highest herbicide treatment, which had also received no nutrients. There was a negative relationship between chironomid abundance and macrophyte cover on the treated sides of wetlands. Fertilizer application did not appear to compound the effects of the herbicide treatments. Although direct toxicity of Roundup WeatherMax was not apparent, the authors observed longer-term impacts, suggesting that the indirect effects of this herbicide deserve more consideration when assessing the ecological risk of using herbicides in proximity to wetlands. PMID:24899169

  9. Small Changes in pH Have Direct Effects on Marine Bacterial Community Composition: A Microcosm Approach

    PubMed Central

    Krause, Evamaria; Wichels, Antje; Giménez, Luis; Lunau, Mirko; Schilhabel, Markus B.; Gerdts, Gunnar

    2012-01-01

    As the atmospheric CO2 concentration rises, more CO2 will dissolve in the oceans, leading to a reduction in pH. Effects of ocean acidification on bacterial communities have mainly been studied in biologically complex systems, in which indirect effects, mediated through food web interactions, come into play. These approaches come close to nature but suffer from low replication and neglect seasonality. To comprehensively investigate direct pH effects, we conducted highly-replicated laboratory acidification experiments with the natural bacterial community from Helgoland Roads (North Sea). Seasonal variability was accounted for by repeating the experiment four times (spring, summer, autumn, winter). Three dilution approaches were used to select for different ecological strategies, i.e. fast-growing or low-nutrient adapted bacteria. The pH levels investigated were in situ seawater pH (8.15–8.22), pH 7.82 and pH 7.67, representing the present-day situation and two acidification scenarios projected for the North Sea for the year 2100. In all seasons, both automated ribosomal intergenic spacer analysis and 16S ribosomal amplicon pyrosequencing revealed pH-dependent community shifts for two of the dilution approaches. Bacteria susceptible to changes in pH were different members of Gammaproteobacteria, Flavobacteriaceae, Rhodobacteraceae, Campylobacteraceae and further less abundant groups. Their specific response to reduced pH was often context-dependent. Bacterial abundance was not influenced by pH. Our findings suggest that already moderate changes in pH have the potential to cause compositional shifts, depending on the community assembly and environmental factors. By identifying pH-susceptible groups, this study provides insights for more directed, in-depth community analyses in large-scale and long-term experiments. PMID:23071704

  10. 75 FR 15756 - Small Business Innovation Research Program Policy Directive

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ...ADMINISTRATION RIN 3244-AF61 Small Business Innovation Research Program Policy...a final amendment to the Small Business Innovation Research (SBIR) Program...to the Policy Directive; Small Business Innovation Research Program To:...

  11. Simple models of small-world networks with directed links.

    PubMed

    Ramezanpour, A; Karimipour, V

    2002-09-01

    We investigate the effect of directed short- and long-range connections in a simple model of a small-world network. Our model is one in which we can determine many quantities of interest by an exact analytical method. We calculate the function V(T), defined as the number of sites affected up to time T when a naive spreading process starts in the network. As opposed to shortcuts, the presence of unfavorable bonds has a negative effect on this quantity. Hence, the spreading process may not be able to affect all of the network. We define and calculate a quantity identified as the average size of the accessible world in our model. The interplay of shortcuts and unfavorable bonds on the small world properties is studied. PMID:12366205

  12. Direct Elastic Imaging of a Small Inclusion

    Microsoft Academic Search

    Habib Ammari; Pierre Calmon; Ekaterina Iakovleva

    2008-01-01

    In this paper we consider the problem of locating a small three-dimensional elastic inclusion, using arrays of elastic source transmitters and receivers. This procedure yields th e multi-static response matrix that is characteristic of the e lastic inclusion. We show how the eigenvalue structure of this matrix can be employed within the framework of a non-iterative method of MUSIC (standing

  13. A direct method of computing small divisors in planetary theory

    Microsoft Academic Search

    R. Dvorak

    1982-01-01

    Three approaches used in treating the problem of small divisors, namely the strict numerical approach, the analytical method, and the direct approach, are described. The direct approach, which is a combination of the other two, is developed here. A special expression of the Lagrange equations in an analytical form is first found. Then the numerical values for the desired small

  14. Turbulence Effects at Small Scales

    E-print Network

    A. Beresnyak; A. Lazarian

    2006-10-26

    It is most natural to assume that mysterious Small Ionized and Neutral Structures (SINS) indiffuse ISM arise from turbulence. There are two obvious problem with such an explanation, however. First of all, it is generally believed that at the small scales turbulence should be damped. Second, turbulence with Kolmogorov spectrum cannot be the responsible for the SINS. We consider, however, effects, that provide spectral index flatter than the Kolmogorov one and allow action at very small scales. These are the shocks that arise in high Mach number turbulence and transfer of energy to small scales by instabilities in cosmic rays. Our examples indicate that the origin of SINS may be discovered through systematic studies of astrophysical turbulence.

  15. The Problems with Access to Compulsory Education in China and the Effects of the Policy of Direct Subsidies to Students: An Empirical Study Based on a Small Sample

    ERIC Educational Resources Information Center

    Yanqing, Ding

    2012-01-01

    After a brief review of the achievements and the problems in compulsory education enrollment in the thirty years since the reform and opening up, this study analyzes the current compulsory education enrollment and dropout rates in China's least-developed regions and the factors affecting school enrollment based on survey data from a small sample…

  16. Making the Most of Small Effects

    ERIC Educational Resources Information Center

    Thompson, Ross A.

    2009-01-01

    The idea that classroom social ecologies are shaped by the aggregate effects of peers' prior care experiences is provocative, even though the evidence is weak that this explains the small and diminishing effect of childcare experience in the National Institute of Child Health and Human Development study. Small effects may indeed be small effects,…

  17. Directional solidification cells with grooves for a small partition coefficient

    NASA Astrophysics Data System (ADS)

    Weeks, John D.; van Saarloos, Wim

    1989-03-01

    Using the asymptotic matching procedure of Dombre and Hakim, we determine properties of the steady-state cellular structures with deep narrow grooves observed in directional solidification experiments. The method is valid in the experimentally relevant region of small partition coefficient and finite Péclet number. An extension of the Scheil equation for the grooves is given, and the importance of conservation in determining the groove closing is pointed out.

  18. [Direct and indirect effects of mineral water Naftusia and its components on the sodium-potassium pump of the small-intestinal epithelium in rats].

    PubMed

    Prokopenko, O N; Kharlamova, O N; Iaremenko, M S

    1990-01-01

    Experiments on rats have shown that intragastric single introduction of mineral water Naftusia to animals in a dose of 1.5% of the body weight of animals induces sodium accumulation in the small intestine epithelium, that is a result of Na(+)-, K(+)-pump inhibition by fatty acids of this water. Naftusia absorption induces appearance of inhibitors of Na(+)-, K(+)-ATPase enzymic system in blood serum of rats. Artificial salt Naftusia analog (ASNA) has induced contrary changes in the water-electrolytic balance and activated Na(+)-, K(+)-ATPase. Blood serum of ASNA-loaded rats acquired ability to activate Na(+)-, K(+)-pump of epitheliocytes in intact rats. PMID:2163335

  19. Directional Solidification and Convection in Small Diameter Crucibles

    NASA Technical Reports Server (NTRS)

    Chen, J.; Sung, P. K.; Tewari, S. N.; Poirier, D. R.; DeGroh, H. C., III

    2003-01-01

    Pb-2.2 wt% Sb alloy was directionally solidified in 1, 2, 3 and 7 mm diameter crucibles. Pb-Sb alloy presents a solutally unstable case. Under plane-front conditions, the resulting macrosegregation along the solidified length indicates that convection persists even in the 1 mm diameter crucible. Al-2 wt% Cu alloy was directionally solidified because this alloy was expected to be stable with respect to convection. Nevertheless, the resulting macrosegregation pattern and the microstructure in solidified examples indicated the presence of convection. Simulations performed for both alloys show that convection persists for crucibles as small as 0.6 mm of diameter. For the solutally stable alloy, Al-2 wt% Cu, the simulations indicate that the convection arises from a lateral temperature gradient.

  20. Novel small-size directional antenna for UWB WBAN\\/WPAN applications

    Microsoft Academic Search

    Maciej Klemm; I. z. Kovacs; Gert F. Pedersen; Gerhard Tröster

    2005-01-01

    This paper presents a novel small-size directional antenna design for ultrawide-band wireless body area networks\\/wireless personal area networks applications. The design is based on a typical slot antenna structure with an added reflector in order to achieve directionality. The effects of different antenna parameters and human body proximity on the radiation characteristics are analyzed. Antenna measurements with an optic RF

  1. Natural aerosol direct and indirect radiative effects

    NASA Astrophysics Data System (ADS)

    Rap, Alexandru; Scott, Catherine E.; Spracklen, Dominick V.; Bellouin, Nicolas; Forster, Piers M.; Carslaw, Kenneth S.; Schmidt, Anja; Mann, Graham

    2013-06-01

    Natural aerosol plays a significant role in the Earth's system due to its ability to alter the radiative balance of the Earth. Here we use a global aerosol microphysics model together with a radiative transfer model to estimate radiative effects for five natural aerosol sources in the present-day atmosphere: dimethyl sulfide (DMS), sea-salt, volcanoes, monoterpenes, and wildfires. We calculate large annual global mean aerosol direct and cloud albedo effects especially for DMS-derived sulfate (-0.23 Wm-2 and -0.76 Wm-2, respectively), volcanic sulfate (-0.21 Wm-2 and -0.61 Wm-2) and sea-salt (-0.44 Wm-2 and -0.04 Wm-2). The cloud albedo effect responds nonlinearly to changes in emission source strengths. The natural sources have both markedly different radiative efficiencies and indirect/direct radiative effect ratios. Aerosol sources that contribute a large number of small particles (DMS-derived and volcanic sulfate) are highly effective at influencing cloud albedo per unit of aerosol mass burden.

  2. EFFECTS OF WATERSHED DISTURBANCE ON SMALL STREAMS

    EPA Science Inventory

    This presentation presents the effects of watershed disturbance on small streams. The South Fork Broad River Watershed was studied to evaluate the use of landscape indicators to predict pollutant loading at small spatial scales and to develop indicators of pollutants. Also studie...

  3. Are Teacher Effects Larger in Small Classes?

    ERIC Educational Resources Information Center

    Konstantopoulos, Spyros; Sun, Min

    2014-01-01

    Teachers spend most of their time in school in classrooms, and their instruction and teaching practices may be affected by classroom context such as class size. We examine whether teacher effects interact with classroom context such as class size. Specifically, we seek to determine whether teacher effects are more pronounced in small classes than…

  4. Thermodynamic effects of linear dissipative small deformations

    Microsoft Academic Search

    Afshin Anssari-Benam; Giuseppe Viola; Theodosios Korakianitis

    2010-01-01

    This paper presents a phenomenological model of dissipative losses manifested as heat transfer effects in small linear deformations\\u000a of solid continua. The impetus is the need for a unified theory characterizing heat transfer effects (called “stretching calorimetry”\\u000a in the literature) on the mechanics of deformations from a macroscopic point of view, overcoming the fragmentary description\\u000a of these thermodynamic effects in

  5. The effect of a miniature argon flow rate on the spectral characteristics of a direct current atmospheric pressure glow micro-discharge between an argon microjet and a small sized flowing liquid cathode

    NASA Astrophysics Data System (ADS)

    Jamróz, Piotr; ?yrnicki, Wies?aw; Pohl, Pawe?

    2012-07-01

    A stable direct current atmospheric pressure glow microdischarge (dc-?APGD) was generated between a miniature Ar flow microjet and a small sized flowing liquid cathode. The microdischarge was operated in the open to air atmosphere. High energy species, including OH, NH, NO, N2, H, O and Ar were identified in the emission spectra of this microdischarge. Additionally, atomic lines of metals dissolved in water solutions were easily excited. The near cathode and the near anode zones of the microdischarge were investigated as a function of an Ar flow rate up to 300 sccm. The spectroscopic parameters, i.e., the excitation, the vibrational and the rotational temperatures as well as the electron number density, were determined in the near cathode and the near anode regions of the microdischarge. In the near cathode region, the rotational temperatures obtained for OH (2000-2600 K) and N2 bands (1600-1950 K) were significantly lower than the excitation temperatures of Ar (7400 K-7800 K) and H (11 000-15 500 K) atoms. Vibrational temperatures of N2, OH and NO varied from 3400 to 4000 K, from 2900 to 3400 K and from 2700 to 3000 K, respectively. In the near anode region, rotational temperatures of OH (350-1750 K) and N2 (400-1350 K) and excitation temperatures of Ar (5200-5500 K) and H (3600-12 600 K) atoms were lower than those measured in the near cathode region. The effect of the introduction of a liquid sample on the microdischarge radiation and spectroscopic parameters was also investigated in the near cathode zone. The electron number density was calculated from the Stark broadening of the H? line and equals to (0.25-1.1) × 1015 cm- 3 and (0.68-1.2) × 1015 cm- 3 in the near cathode and the near anode zones, respectively. The intensity of the Na I emission line and the signal to background ratio (SBR) of this line were investigated in both zones to evaluate the excitation properties of the developed excitation microsource. The limit of detection for Na was determined at the level of 3 ng mL- 1.

  6. Small Class Size and Its Effects.

    ERIC Educational Resources Information Center

    Biddle, Bruce J.; Berliner, David C.

    2002-01-01

    Describes several prominent early grades small-class-size projects and their effects on student achievement: Indiana's Project Prime Time, Tennessee's Project STAR (Student/Teacher Achievement Ratio), Wisconsin's SAGE (Student Achievement Guarantee in Education) Program, and the California class-size-reduction program. Lists several conclusions,…

  7. Direct oxide reduction demonstration, small-scale studies

    Microsoft Academic Search

    J. L. Long; D. J. Santi; D. C. Fisher; T. J. Humiston

    1991-01-01

    This project was initiated to provide process design information to the Plutonium Recovery Project (PRP). Although direct oxide reduction (DOR) has been operated in a production mode both at the Rocky Flats Plant (now operated by EG G, Inc.) and Los Alamos National Laboratory, many aspects of the process are ill-defined. Because the PRP plans include significant DOR capability, a

  8. Direct oxide reduction demonstration, small-scale studies

    SciTech Connect

    Long, J.L.; Santi, D.J.; Fisher, D.C.; Humiston, T.J.

    1991-12-09

    This project was initiated to provide process design information to the Plutonium Recovery Project (PRP). Although direct oxide reduction (DOR) has been operated in a production mode both at the Rocky Flats Plant (now operated by EG&G, Inc.) and Los Alamos National Laboratory, many aspects of the process are ill-defined. Because the PRP plans include significant DOR capability, a well-defined process should minimize capital cost and maximize productivity. Reduced radiation exposure may also be realized. A detailed, statistically valid investigation of the direct oxide reduction process was carried out utilizing 100 grams or less of plutonium dioxide per experiment. Conditions were established for obtaining 95% + yields. Conclusions drawn from the results of the experimental work were utilized to make recommendations for future large-scale investigative and confirmative work as well large-scale production demonstration work. 4 refs., 5 figs., 14 tabs.

  9. Combination of earthquake direction effects

    SciTech Connect

    Morrone, A.

    1983-01-01

    The correct application of the square root of the sum of the squares (SRSS) rule is presented for obtaining the combined responses of a subsystem to seismic excitations given by orthogonal earthquake components represented by system response spectra. Alternate methods of applying the SRSS, which are sometimes used either for simplicity or due to different interpretation, are evaluated and compared with the correct method. The evaluations consider the following four cases: (1) the correct method which combines the responses in a particular direction given by each earthquake component as a last step, (2) a generally unconservative method whereby both the system response spectra and the resulting subsystem responses are combined by the SRSS, (3) a method which can be unconservative for unequal earthquake components where the system response spectra are combined by the absolute sum and the resulting responses by the SRSS, and (4) a conservative method which combines the system response spectra by the SRSS but adds the resulting responses absolutely. In addition, three conditions of directional coupling are considered for all cases. These are full directional coupling, only the system coupled, and no coupling. A comparison of the subsystem combined responses with the various SRSS methods is presented in tabular form which gives the applicable equations for each case and coupling condition.

  10. Estimation of Directional Stability Derivatives at Small Angles and Subsonic and Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Goodwin, Frederick K.; Kaattari, George E.

    1958-01-01

    Methods are presented for estimating the directional stability derivative increments contributed by the stabilizing surfaces of subsonic and supersonic aircraft. These methods are strictly applicable at zero angle of attack and small angles of sideslip. The procedure of totaling the incremental coefficients to obtain an estimation of the total empennage side-force and yawing-moment coefficient derivatives is also shown, together with numerical examples. A correlation is presented between estimated and experimental incremental coefficients which indicates that the methods of this report generally estimate the increment of side force gained by the addition of a panel to within +/-10 percent of the experimental value while the yawing-moment increment is generally estimated to within +/-20 percent. This is true for both subsonic and supersonic Mach numbers. An example application of the methods to one of the problems in directional stability, that of minimizing the effect of Mach number on the side-force coefficient derivative of the empennage, is discussed.

  11. Stable directions for small nonlinear Dirac standing waves

    E-print Network

    Nabile Boussaid

    2006-04-27

    We prove that for a Dirac operator with no resonance at thresholds nor eigenvalue at thresholds the propagator satisfies propagation and dispersive estimates. When this linear operator has only two simple eigenvalues close enough, we study an associated class of nonlinear Dirac equations which have stationary solutions. As an application of our decay estimates, we show that these solutions have stable directions which are tangent to the subspaces associated with the continuous spectrum of the Dirac operator. This result is the analogue, in the Dirac case, of a theorem by Tsai and Yau about the Schr\\"{o}dinger equation. To our knowledge, the present work is the first mathematical study of the stability problem for a nonlinear Dirac equation.

  12. Effective separation technique for small diameter whiskers.

    NASA Technical Reports Server (NTRS)

    Westfall, L. J.

    1972-01-01

    Description of a technique for separating small-diameter whiskers from the as-grown matt by gently agitating the whisker matts in a solution of deionized or distilled water for six to eight hours. High-strength Al2O3 whiskers were effectively separated by this technique, comprising an average 48% of the original weight of the whisker matt. According to estimation, more than 90% of separated whiskers had diameters between 0.7 and 2.0 microns.

  13. 77 FR 46805 - Small Business Innovation Research Program Policy Directive

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ...which is the end of FY 2015, DoD may use not more than...compelling reason that additional investment in SBIR or STTR technologies...such transfer would be more cost effective than recovery of the property...participate in or conduct energy efficiency or renewable energy...

  14. Direct Instruction News: Effective School Practices, 2003.

    ERIC Educational Resources Information Center

    Tarver, Sara G., Ed.

    2003-01-01

    The mission of the Association for Direct Instruction is to promote the improvement of effective educational methods. This journal, "Direct Instruction News," is their publication. The Spring 2003 (Volume 3, Number 1) contains the following articles: "Implementing DI Successfully" (Sara G. Tarver); "Textbooks: What?" (Bob Dixon); "Introduction to…

  15. A Small Modular Laboratory Hall Effect Thruster

    NASA Astrophysics Data System (ADS)

    Lee, Ty Davis

    Electric propulsion technologies promise to revolutionize access to space, opening the door for mission concepts unfeasible by traditional propulsion methods alone. The Hall effect thruster is a relatively high thrust, moderate specific impulse electric propulsion device that belongs to the class of electrostatic thrusters. Hall effect thrusters benefit from an extensive flight history, and offer significant performance and cost advantages when compared to other forms of electric propulsion. Ongoing research on these devices includes the investigation of mechanisms that tend to decrease overall thruster efficiency, as well as the development of new techniques to extend operational lifetimes. This thesis is primarily concerned with the design and construction of a Small Modular Laboratory Hall Effect Thruster (SMLHET), and its operation on argon propellant gas. Particular attention was addressed at low-cost, modular design principles, that would facilitate simple replacement and modification of key thruster parts such as the magnetic circuit and discharge channel. This capability is intended to facilitate future studies of device physics such as anomalous electron transport and magnetic shielding of the channel walls, that have an impact on thruster performance and life. Preliminary results demonstrate SMLHET running on argon in a manner characteristic of Hall effect thrusters, additionally a power balance method was utilized to estimate thruster performance. It is expected that future thruster studies utilizing heavier though more expensive gases like xenon or krypton, will observe increased efficiency and stability.

  16. EFFECTS OF NOZZLE GEOMETRY ON PLUME EXPANSION FOR SMALL THRUSTERS

    Microsoft Academic Search

    Donna Zelesniki; Paul F. Penkot

    systems such that impingement impacts are minimized without compromising performance. The current work The Direct Simulation Monte Carlo method is is specifically directed at applying gas dynamics on the currently being applied to study flowfields of small molecular level to the phenomena associated with thrusters. Accurate prediction of both the internal and viscous flows in nozzles and plumes of small

  17. Analytical fuel property effects--small combustors

    NASA Technical Reports Server (NTRS)

    Sutton, R. D.; Troth, D. L.; Miles, G. A.

    1984-01-01

    The consequences of using broad-property fuels in both conventional and advanced state-of-the-art small gas turbine combustors are assessed. Eight combustor concepts were selected for initial screening, of these, four final combustor concepts were chosen for further detailed analysis. These included the dual orifice injector baseline combustor (a current production 250-C30 engine combustor) two baseline airblast injected modifications, short and piloted prechamber combustors, and an advanced airblast injected, variable geometry air staged combustor. Final predictions employed the use of the STAC-I computer code. This quasi 2-D model includes real fuel properties, effects of injector type on atomization, detailed droplet dynamics, and multistep chemical kinetics. In general, fuel property effects on various combustor concepts can be classified as chemical or physical in nature. Predictions indicate that fuel chemistry has a significant effect on flame radiation, liner wall temperature, and smoke emission. Fuel physical properties that govern atomization quality and evaporation rates are predicted to affect ignition and lean-blowout limits, combustion efficiency, unburned hydrocarbon, and carbon monoxide emissions.

  18. Laser direct synthesis of silicon nanowire field effect transistors

    NASA Astrophysics Data System (ADS)

    Nam, Woongsik; Mitchell, James I.; Ye, Peide D.; Xu, Xianfan

    2015-02-01

    We demonstrate a single-step, laser-based technique to fabricate silicon nanowire field effect transistors. Boron-doped silicon nanowires are synthesized using a laser-direct-write chemical vapor deposition process, which can produce nanowires as small as 60 nm, far below the diffraction limit of the laser wavelength of 395 nm. In addition, the method has the advantages of in situ doping, catalyst-free growth, and precise control of nanowire position, orientation, and length. Silicon nanowires are directly fabricated on an insulating surface and ready for subsequent device fabrication without the need for transfer and alignment, thus greatly simplifying device fabrication processes. Schottky barrier nanowire field effect transistors with a back-gate configuration are fabricated from the laser-direct-written Si nanowires and electrically characterized.

  19. Internet Small Computer System Interface (iSCSI) Extensions for Remote Direct Memory Access (RDMA)

    Microsoft Academic Search

    M. Chadalapaka; J. Hufferd; U. Elzur; H. Shah; P. Thaler

    Internet Small Computer System Interface (iSCSI) Extensions for Remote Direct Memory Access (RDMA) provides the RDMA data transfer capability to iSCSI by layering iSCSI on top of an RDMA-Capable Protocol, such as the iWARP protocol suite. An RDMA-Capable Protocol provides RDMA Read and Write services, which enable data to be transferred directly into SCSI I\\/O Buffers without intermediate data copies.

  20. Development of a Direct Drive Permanent Magnet Generator for Small Wind Turbines

    Microsoft Academic Search

    Allan Chertok; David Hablanian; Paul McTaggart; DOE Project Officer

    2004-01-01

    In this program, TIAX performed the conceptual design and analysis of an innovative, modular, direct-drive permanent magnet generator (PMG) for use in small wind turbines that range in power rating from 25 kW to 100 kW. TIAX adapted an approach that has been successfully demonstrated in high volume consumer products such as direct-drive washing machines and portable generators. An electromagnetic

  1. Effects of tillage practices and carbofuran exposure on small mammals

    USGS Publications Warehouse

    Albers, P.H.; Linder, G.; Nichols, J.D.

    1990-01-01

    We compared population estimates, body mass, movement, and blood chemistry of small mammals between conventionally tilled and no-till cornfields in Maryland and Pennsylvania to evaluate the effects of tillage practices and carbofuran exposure on small mammals.

  2. Electrokinetic Effects with Small Drops and Bubbles

    NASA Astrophysics Data System (ADS)

    Baygents, James Claude

    Electrokinetic effects with drops and bubbles are studied. We first examine the electrophoresis of drops and bubbles, computing the electrophoretic mobility as a function of the zeta-potential and several other parameters. We find drops and bubbles to be electrophoretically distinct from particles; e.g., conducting drops do not always migrate in the direction that would be anticipated from the sign of their surface charge. The analysis shows the sense of the migration is dictated by the net electrochemical stress acting along the interface and the zeta-potential alone is not sufficient to characterize the surface. For similar reasons, large inviscid spheres tend to remain stationary at modest zeta-potentials and, in contrast to rigid particles, their mobility is actually enhanced by polarization of the double layer. Further, we have uncovered conditions for which the mobility of nonconducting drops is insensitive to the interior viscosity. Next we examine the influence of partial dissociation of ionogenic solutes on electrophoresis, with a view toward understanding, how, and under what conditions, dissociation -association alters the electrokinetics. We find generally that mass-action resists polarization of the diffuse ion cloud and, so, is quantitatively important where double layer polarization and relaxation would otherwise prevail. Mass -action can reduce the mobility of a conducting drop by an order of magnitude, and sizeable decreases (50% and more) in drop mobility are even found at zeta -potentials below 50 mV. Rigid particles are affected less dramatically and quantitative effects rarely exceed 10%; particles are indifferent to partial ionization unless the zeta-potential is high (above ca. 100mV) and akappa > 1. Finally the influence of diffuse charge layers on electrically-induced drop deformations is investigated by revisiting the archetypal problem in electrohydrodynamics: the circulation produced in a drop by an electric field. Singular perturbation methods are employed to constuct a coherent physicochemical description of the regions proximal to the drop surface, including the space charge distribution. The electrokinetic model employed yields predictions of drop deformation consistent with the lumped parameter theory known as the 'leaky dielectric.' Previously it had been thought the leaky dielectric failed to account for the effects of diffuse charge layers on electrohydrodynamic flows.

  3. Rotational effect in two-dimensional cooperative directed transport

    NASA Astrophysics Data System (ADS)

    Qiao, Li-Yan; Li, Yun-yun; Zheng, Zhi-Gang

    2015-02-01

    In this review we investigate the rotation effect in the motion of coupled dimer in a two-dimensional asymmetric periodic potential. Free rotation does not generate directed transport in translational direction, while we find it plays an critical role in the motors motility when the dimer moves under the effect of asymmetry ratchet potential. In the presence of external force, we study the relation between the average current and the force numerically and theoretically. The numerical results show that only appropriate driving force could produce nonzero current and there are current transitions when the force is large enough. An analysis of stability analysis of limit cycles is applied to explain the occurrence of these transitions. Moreover, we numerically simulate the transport of this coupled dimer driven by the random fluctuations in the rotational direction. The existence of noise smooths the current transitions induced by the driving force and the resonance-like peaks which depend on the rod length emerge in small noise strength. Thanks to the noise in the rotational direction, autonomous motion emerges without the external force and large noise could make the current reversal happen. Eventually, the new mechanism to generate directed transport by the rotation is studied.

  4. The small-island effect: fact or artefact?

    Microsoft Academic Search

    Kevin C. Burns; R. Paul McHardy; Shirley Pledger

    2009-01-01

    Positive relationships between species richness and sampling area are perhaps the most pervasive patterns in nature. However, the shape of speciesarea relationships is often highly variable, for reasons that are poorly understood. One such source of variability is the ''small-island effect'', which refers to a decrease in the capacity of sampling area to predict species richness on small islands. Small-island

  5. Telecommunications: The Small College's Tool for Effectiveness.

    ERIC Educational Resources Information Center

    Gutherie-Morse, Barbara; Julian, Charles A.

    1989-01-01

    Considers ways in which telecommunications can ameliorate the staffing crises of small colleges. Describes West Virginia Northern Community College's efforts to serve remote instructional sites using an interactive telecommunications system. Reviews the college's problem, the design and installation of equipment, and selection and training of…

  6. Small Impacts on Mars: Atmospheric Effects

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Nemtchinov, Ivan V.

    2002-01-01

    The objectives of this investigation were to study the interaction of the atmosphere with the surface of Mars through the impact of small objects that would generate dust and set the dust into motion in the atmosphere. The approach involved numerical simulations of impacts and experiments under controlled conditions. Attachment: Atmospheric disturbances and radiation impulses caused by large-meteoroid impact in the surface of Mars.

  7. Small population effects in stochastic population dynamics.

    PubMed

    Percus, Jerome K

    2005-11-01

    The discreteness of units of small populations can produce large fluctuations from a classical continuous representation, especially when null populations play a crucial role. These belong to what are here referred to as emergent and evanescent species. A few model biological systems are introduced in which this is the case, as well as a toy model that suggests a path to avoid the associated mathematical complexities. The corresponding division into null and non-null population sectors is carried out to leading order for the model systems, with promising results. PMID:16005504

  8. Small effects of smoking on visual spatiotemporal processing

    PubMed Central

    Kunchulia, Marina; Pilz, Karin S.; Herzog, Michael H.

    2014-01-01

    Nicotine is an important stimulant that is involved in modulating many neuronal processes, including those related to vision. Nicotine is also thought to play a key role in schizophrenia: A genetic variation of the cholinergic nicotine receptor gene, alpha-7 subunit (CHRNA7) has been shown to be associated with stronger backward masking deficits in schizophrenic patients. In this study, we tested visual backward masking in healthy smokers and non-smokers to further understand the effects of nicotine on spatiotemporal vision. In the first study, we tested 48 participants, a group of non-smokers (n = 12) and three groups of regular smokers that were either nicotine deprived (n = 12), non-deprived (n = 12) or deprived but were allowed to smoke a cigarette directly before the start of the experiment (n = 12). Performance was similar across groups, except for some small negative effects in nicotine-deprived participants. In the second study, we compared backward masking performance between regular smokers and non-smokers for older (n = 37, 13 smokers) and younger (n = 67, 21 smokers) adults. Older adults performed generally worse than younger adults but there were no significant differences in performance between smokers and non-smokers. Taken together, these findings indicate that nicotine has no long-term negative effects on visual spatiotemporal processing as determined by visual backward masking. PMID:25471068

  9. Negative Effects of an Exotic Grass Invasion on Small-Mammal Communities

    PubMed Central

    Freeman, Eric D.; Sharp, Tiffanny R.; Larsen, Randy T.; Knight, Robert N.; Slater, Steven J.; McMillan, Brock R.

    2014-01-01

    Exotic invasive species can directly and indirectly influence natural ecological communities. Cheatgrass (Bromus tectorum) is non-native to the western United States and has invaded large areas of the Great Basin. Changes to the structure and composition of plant communities invaded by cheatgrass likely have effects at higher trophic levels. As a keystone guild in North American deserts, granivorous small mammals drive and maintain plant diversity. Our objective was to assess potential effects of invasion by cheatgrass on small-mammal communities. We sampled small-mammal and plant communities at 70 sites (Great Basin, Utah). We assessed abundance and diversity of the small-mammal community, diversity of the plant community, and the percentage of cheatgrass cover and shrub species. Abundance and diversity of the small-mammal community decreased with increasing abundance of cheatgrass. Similarly, cover of cheatgrass remained a significant predictor of small-mammal abundance even after accounting for the loss of the shrub layer and plant diversity, suggesting that there are direct and indirect effects of cheatgrass. The change in the small-mammal communities associated with invasion of cheatgrass likely has effects through higher and lower trophic levels and has the potential to cause major changes in ecosystem structure and function. PMID:25269073

  10. Negative effects of an exotic grass invasion on small-mammal communities.

    PubMed

    Freeman, Eric D; Sharp, Tiffanny R; Larsen, Randy T; Knight, Robert N; Slater, Steven J; McMillan, Brock R

    2014-01-01

    Exotic invasive species can directly and indirectly influence natural ecological communities. Cheatgrass (Bromus tectorum) is non-native to the western United States and has invaded large areas of the Great Basin. Changes to the structure and composition of plant communities invaded by cheatgrass likely have effects at higher trophic levels. As a keystone guild in North American deserts, granivorous small mammals drive and maintain plant diversity. Our objective was to assess potential effects of invasion by cheatgrass on small-mammal communities. We sampled small-mammal and plant communities at 70 sites (Great Basin, Utah). We assessed abundance and diversity of the small-mammal community, diversity of the plant community, and the percentage of cheatgrass cover and shrub species. Abundance and diversity of the small-mammal community decreased with increasing abundance of cheatgrass. Similarly, cover of cheatgrass remained a significant predictor of small-mammal abundance even after accounting for the loss of the shrub layer and plant diversity, suggesting that there are direct and indirect effects of cheatgrass. The change in the small-mammal communities associated with invasion of cheatgrass likely has effects through higher and lower trophic levels and has the potential to cause major changes in ecosystem structure and function. PMID:25269073

  11. Cost effective propulsion systems for small satellites using butane propellant

    Microsoft Academic Search

    R. Amri; C. Underwood; M. Sweeting

    2002-01-01

    This paper will describe the work performed at the Surrey Space Centre to produce cost effective propulsion systems for small spacecraft with relatively low deltaV (?V) requirements. Traditionally, cold gas nitrogen systems have been used for this type of application, however they have high storage volume requirements. This can be a problem on small spacecraft, which are typically volume limited.

  12. Effectiveness of Small Group Social Skills Lessons with Elementary Students

    ERIC Educational Resources Information Center

    Chupp, Amy I.; Boes, Susan R.

    2012-01-01

    This action research study (ARS) describes the effectiveness of small group social skills lessons with elementary students, using "Too Good for Violence: A Curriculum for Non-violent Living" by the Mendez Foundation. The school counselor and school social worker taught the curriculum in a structured small group of 4th grade students in 8 weekly…

  13. Development of a Direct Drive Permanent Magnet Generator for Small Wind Turbines

    SciTech Connect

    Chertok, Allan; Hablanian, David; McTaggart, Paul; DOE Project Officer - Keith Bennett

    2004-11-16

    In this program, TIAX performed the conceptual design and analysis of an innovative, modular, direct-drive permanent magnet generator (PMG) for use in small wind turbines that range in power rating from 25 kW to 100 kW. TIAX adapted an approach that has been successfully demonstrated in high volume consumer products such as direct-drive washing machines and portable generators. An electromagnetic model was created and the modular PMG design was compared to an illustrative non-modular design. The resulting projections show that the modular design can achieve significant reductions in size, weight, and manufacturing cost without compromising efficiency. Reducing generator size and weight can also lower the size and weight of other wind turbine components and hence their manufacturing cost.

  14. Determination of small-scale flow directions and velocities in the hyporheic interstitial

    NASA Astrophysics Data System (ADS)

    Angermann, L.; Fleckenstein, J.; Nützmann, G.; Lewandowski, J.

    2009-04-01

    The hyporheic interstitial is a hydraulically dynamic and biogeochemical active interface between surface water and groundwater. Depending on the hydraulic boundary conditions and the connectivity with the adjacent aquifer, infiltrating and exfiltrating water pass through it. In addition to those larger scale flow patterns flow at the centimetre scale is influenced by streambed morphology, such as pool-ripple sequences, boulders and woody debris, and the hydrodynamics in the flowing water resulting in a very heterogeneous pattern of flow in the shallow sediment. Patterns of exchange at this scale control the supply of oxygen and nutrients to the sediments and are in turn crucial for biogeochemical turnover. To investigate flow velocity and flow direction in the hyporheic interstitial in situ, a method employing heat as a tracer was developed. The method was tested in a low gradient stream (mean slope of 1.8 0/00), with sandy streambed in Brandenburg, Germany (river Schlaube). The movement of a heat pulse emitted by a small point source is detected by temperature sensors attached to four rods (four sensors on each rod) that are vertically driven into the sediment in a concentric circle with a radius of 3 to 4.5 cm around the heat source. The resulting breakthrough-curves give evidence of flow velocities and flow directions in three dimensions, accounting for the local heterogeneities of the sediment. Patterns of flow direction were found to be quite heterogeneous even on small scales of a few decimetres. Interestingly at several locations flow in the sediment was directed opposite to surface flow. Measured flow velocities of up to 1.75 cm min-1 are several orders of magnitude larger than values previously reported in the literature. As this method is non-destructive it allows repetition of measurements and long-term investigations to assess the variability in time. Furthermore it is well suited for a combined application with sampling devices such as pore water peepers.

  15. Contrasting the direct radiative effect and direct radiative forcing of aerosols

    E-print Network

    Heald, Colette L.

    The direct radiative effect (DRE) of aerosols, which is the instantaneous radiative impact of all atmospheric particles on the Earth's energy balance, is sometimes confused with the direct radiative forcing (DRF), which ...

  16. Comparing the effect of different spine and leg designs for a small, bounding quadruped robot

    E-print Network

    Thévenaz, Jacques

    Comparing the effect of different spine and leg designs for a small, bounding quadruped robot Peter ***Chair of Biomechatronics, Technische Universit¨at Ilmenau, Germany 1 Introduction We present Lynx-robot, a quadruped, modular, compliant robot. It features an either directly actuated, single-joint spine design

  17. Direct Demonstration of the Greenhouse Effect

    NASA Astrophysics Data System (ADS)

    Jaffe, D. A.; Malashanka, S.; Call, K.; Bernays, N.

    2012-12-01

    Consider these three "theories:" climate change, evolution, and gravity. Why are two of them hotly debated by non-scientists, but not gravity? In part, the answer is that climate change and evolution are more complex processes and not readily observable over short time scales to most people. In contrast, the "theory of gravity" is tested every day by billions of people world-wide and is therefore not challenged. While there are numerous "demonstrations" of the greenhouse effect available online, unfortunately, many of them are based on poor understanding of the physical principles involved. For this reason, we sought to develop simple and direct experiments that would demonstrate aspects of the greenhouse effect that would be suitable for museums, K-12, and/or college classrooms. We will describe two experiments. In the first, we use a simple plexiglass tube, approximately 12 cm long, with IR transparent windows. The tube is first filled with dry nitrogen and exposed to an IR heat lamp. Following this, the tube is filled with pure, dry CO2. Both tubes warm up, but the tube filled with CO2 ends up about 0.7 degrees C warmer. It is useful to compare this 12 cm column of CO2 to the column in the earth's atmosphere, which is equivalent to approximately 2.7 meters of pure CO2. This demonstration would be suitable for museum exhibits to demonstrate the physical basis of CO2 heating in the atmosphere. In the second experiment, we use FTIR spectroscopy to quantify the CO2 content of ambient air and indoor/classroom air. For this experiment, we use a commercial standard of 350 ppm CO2 to calibrate the absorption features. Once the CO2 content of ambient air is found, it is useful for students to compare their observed value to background data (e.g. NOAA site in Hawaii) and/or the "Keeling Curve". This leads into a discussion on causes for local variations and the long-term trends. This experiment is currently used in our general chemistry class but could be used in many other science classes. Both of the above experiments should lead to a greater understanding of the scientific basis for the greenhouse effect.

  18. A reciprocating solar-heated engine utilizing direct absorption by small particles

    NASA Astrophysics Data System (ADS)

    Hunt, A. J.; Hull, P. G.

    1984-02-01

    A new type of reciprocating solar engine utilizing small particles to absorb concentrated sunlight directly within the cylinders is described. The engine operates by drawing an air-particle mixture into the cylinder, compressing the mixture, opening an optical valve to allow concentrated sunlight to enter through a window in the top of the cylinder head, absorbing the solar flux with the particles, and converting the heat trapped by the air-particle mixture into mechanical energy with the downward stroke of piston. It differs from other gas driven heat engines using solar energy in three main respects. First, the radiant flux is deposited directly in the working fluid inside the cylinder; second, the heat is directed to the appropriate cylinder by controlling the solar flux by an optical system; third, the gas is heated during a significant portion of the compression stroke. The thermodynamic efficiency of the engine is calculated using an analytical model and is compared to several other engine cycles of interest.

  19. Design Study of Coated Conductor Direct Drive Wind Turbine Generator for Small Scale Demonstration

    NASA Astrophysics Data System (ADS)

    Abrahamsen, Asger B.; Jensen, Bogi B.

    We have investigated the properties of a superconducting direct drive generator suitable for demonstration in a small scale 11 kW wind turbine. The engineering current density of the superconducting ?eld windings is based on properties of coated conductors wound into coils holding of the order 68 meters of tape. The active mass of the generators has been investigated as function of the number of poles and a 4 pole generator is suggested as a feasible starting point of an in-?eld demonstration of the system reliability. An active mass of m = 421 kg and a usage of 3.45 km of tape will be needed to realize such a generator with a peak ?ux density in the airgap of B0 = 1.5 T.

  20. Direct pericardial involvement of non-small cell lung cancer rapidly developing pericardial constriction.

    PubMed

    Wakamatsu, Toshihide; Koizumi, Tomonobu; Urushihata, Kazuhisa; Fujimoto, Keisaku; Uchikawa, Shiniichirou; Kubo, Keishi; Iwamura, Ayahiko; Yazawa, Masanobu

    2004-10-01

    A 71-year-old male, who had been followed up after being treated with chemo-radiotherapy for non-small cell lung cancer (adenocarcinoma), rapidly developed dyspnea and mild fever. Radiographs showed left pleural effusion and cardiomegaly, and echocardiographic examination revealed echo-free space, suggesting a pericardial effusion. The patient was treated conservatively without any surgical procedures such as pericardiocentesis. Disappearance of the echo-free space was followed by development of pericardial constriction within two months. At post-mortem examination, a direct extension to the pericardium from the primary lesion of the right upper lobe through the mediastinum was observed. The rapid development of pericardial constriction is extremely rare in patients with malignant pericarditis. PMID:15591462

  1. Heads or tails, does it make a difference? Capsule endoscope direction in small bowel studies is important.

    PubMed

    Adler, S N; Metzger, Y C

    2007-10-01

    Capsule endoscopy has opened the small bowel for direct inspection. However, the diagnostic sensitivity of capsule endoscopy is not 100 %. We have observed that forward orientation and backward orientation of the camera in the small bowel provide different information on pathological findings. Double-head capsule endoscopy may offer the answer to this problem. PMID:17968808

  2. Small Molecule-Mediated Directed Differentiation of Human Embryonic Stem Cells Toward Ventricular Cardiomyocytes

    PubMed Central

    Senyei, Grant D.; Hansen, Jens; Kong, Chi-Wing; Azeloglu, Evren U.; Stillitano, Francesca; Lieu, Deborah K.; Wang, Jiaxian; Ren, Lihuan; Hulot, Jean-Sebastien; Iyengar, Ravi; Li, Ronald A.; Hajjar, Roger J.

    2014-01-01

    The generation of human ventricular cardiomyocytes from human embryonic stem cells and/or induced pluripotent stem cells could fulfill the demand for therapeutic applications and in vitro pharmacological research; however, the production of a homogeneous population of ventricular cardiomyocytes remains a major limitation. By combining small molecules and growth factors, we developed a fully chemically defined, directed differentiation system to generate ventricular-like cardiomyocytes (VCMs) from human embryonic stem cells and induced pluripotent stem cells with high efficiency and reproducibility. Molecular characterization revealed that the differentiation recapitulated the developmental steps of cardiovascular fate specification. Electrophysiological analyses further illustrated the generation of a highly enriched population of VCMs. These chemically induced VCMs exhibited the expected cardiac electrophysiological and calcium handling properties as well as the appropriate chronotropic responses to cardioactive compounds. In addition, using an integrated computational and experimental systems biology approach, we demonstrated that the modulation of the canonical Wnt pathway by the small molecule IWR-1 plays a key role in cardiomyocyte subtype specification. In summary, we developed a reproducible and efficient experimental platform that facilitates a chemical genetics-based interrogation of signaling pathways during cardiogenesis that bypasses the limitations of genetic approaches and provides a valuable source of ventricular cardiomyocytes for pharmacological screenings as well as cell replacement therapies. PMID:24324277

  3. Directing stormwater into small, urban, vegetated spaces: interacting biophysical and institutional constraints

    NASA Astrophysics Data System (ADS)

    Montalto, F. A.; Bartrand, T.

    2012-12-01

    Billions of dollars have been set aside by urban watershed managers to direct stormwater into new, decentralized networks of small vegetated spaces. The design of these spaces, and their ultimate distribution across space and time could fundamentally change the ecohydrologic properties of urban ecosystems. Our ability to forecast such changes, however, is contingent upon the development of new modeling platforms that simulate the various climatic, biophysical, as well as socio-technical forces at play in the urban water environment. An agent-based model was developed to explore the potential interplay of these phenomena in a small neighborhood of South Philadelphia. In the model, new urban green spaces "emerge" in space and time as the byproduct of alternative choices made by the local water utility, as well as local stakeholders. Several different model scenarios will be presented demonstrating that future changes to urban ecohydrology will be potentially as much determined by the physical conditions in cities, as by social and institutional preferences and behavior.

  4. Cooperation in the snowdrift game on directed small-world networks under self-questioning and noisy conditions

    NASA Astrophysics Data System (ADS)

    Qiu, Tian; Hadzibeganovic, Tarik; Chen, Guang; Zhong, Li-Xin; Wu, Xiao-Run

    2010-12-01

    Cooperation in the evolutionary snowdrift game with a self-questioning updating mechanism is studied on annealed and quenched small-world networks with directed couplings. Around the payoff parameter value r=0.5, we find a size-invariant symmetrical cooperation effect. While generally suppressing cooperation for r>0.5 payoffs, rewired networks facilitated cooperative behavior for r<0.5. Fair amounts of noise were found to break the observed symmetry and further weaken cooperation at relatively large values of r. However, in the absence of noise, the self-questioning mechanism recovers symmetrical behavior and elevates altruism even under large-reward conditions. Our results suggest that an updating mechanism of this type is necessary to stabilize cooperation in a spatially structured environment which is otherwise detrimental to cooperative behavior, especially at high cost-to-benefit ratios. Additionally, we employ component and local stability analyses to better understand the nature of the manifested dynamics.

  5. Derivative expansion at small mass for the spinor effective action

    SciTech Connect

    Dunne, Gerald V. [Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046 (United States); Huet, Adolfo [Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046 (United States); Instituto de Fisica y Matematicas, Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoacan 58040 (Mexico); Hur, Jin [School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea, Republic of); Min, Hyunsoo [Department of Physics, University of Seoul, Seoul 130-743 (Korea, Republic of)

    2011-05-15

    We study the small-mass limit of the one-loop spinor effective action, comparing the derivative expansion approximation with exact numerical results that are obtained from an extension to spinor theories of the partial-wave cutoff method. In this approach, one can compute numerically the renormalized one-loop effective action for radially separable gauge field background fields in spinor QED. We highlight an important difference between the small-mass limit of the derivative expansion for spinor and scalar theories.

  6. Antidiabetic effects of glucokinase regulatory protein small-molecule disruptors

    NASA Astrophysics Data System (ADS)

    Lloyd, David J.; St Jean, David J.; Kurzeja, Robert J. M.; Wahl, Robert C.; Michelsen, Klaus; Cupples, Rod; Chen, Michelle; Wu, John; Sivits, Glenn; Helmering, Joan; Komorowski, Renée; Ashton, Kate S.; Pennington, Lewis D.; Fotsch, Christopher; Vazir, Mukta; Chen, Kui; Chmait, Samer; Zhang, Jiandong; Liu, Longbin; Norman, Mark H.; Andrews, Kristin L.; Bartberger, Michael D.; van, Gwyneth; Galbreath, Elizabeth J.; Vonderfecht, Steven L.; Wang, Minghan; Jordan, Steven R.; Véniant, Murielle M.; Hale, Clarence

    2013-12-01

    Glucose homeostasis is a vital and complex process, and its disruption can cause hyperglycaemia and type II diabetes mellitus. Glucokinase (GK), a key enzyme that regulates glucose homeostasis, converts glucose to glucose-6-phosphate in pancreatic ?-cells, liver hepatocytes, specific hypothalamic neurons, and gut enterocytes. In hepatocytes, GK regulates glucose uptake and glycogen synthesis, suppresses glucose production, and is subject to the endogenous inhibitor GK regulatory protein (GKRP). During fasting, GKRP binds, inactivates and sequesters GK in the nucleus, which removes GK from the gluconeogenic process and prevents a futile cycle of glucose phosphorylation. Compounds that directly hyperactivate GK (GK activators) lower blood glucose levels and are being evaluated clinically as potential therapeutics for the treatment of type II diabetes mellitus. However, initial reports indicate that an increased risk of hypoglycaemia is associated with some GK activators. To mitigate the risk of hypoglycaemia, we sought to increase GK activity by blocking GKRP. Here we describe the identification of two potent small-molecule GK-GKRP disruptors (AMG-1694 and AMG-3969) that normalized blood glucose levels in several rodent models of diabetes. These compounds potently reversed the inhibitory effect of GKRP on GK activity and promoted GK translocation both in vitro (isolated hepatocytes) and in vivo (liver). A co-crystal structure of full-length human GKRP in complex with AMG-1694 revealed a previously unknown binding pocket in GKRP distinct from that of the phosphofructose-binding site. Furthermore, with AMG-1694 and AMG-3969 (but not GK activators), blood glucose lowering was restricted to diabetic and not normoglycaemic animals. These findings exploit a new cellular mechanism for lowering blood glucose levels with reduced potential for hypoglycaemic risk in patients with type II diabetes mellitus.

  7. Using the sensitive dependence of chaos (the butterfly effect'') to direct trajectories in an experimental chaotic system

    SciTech Connect

    Shinbrot, T.; Ditto, W.; Grebogi, C.; Ott, E.; Spano, M.; Yorke, J.A. (University of Maryland, College Park, Maryland 20742 (United States) Department of Physics, The College of Wooster, Wooster, Ohio 44691 (United States) Naval Surface Warfare Center, Silver Spring, Maryland 20902 (United States))

    1992-05-11

    In this paper we present the first experimental verification that the sensitivity of a chaotic system to small perturbations (the butterfly effect'') can be used to rapidly direct orbits from an arbitrary initial state to an arbitrary accessible desired state.

  8. Empirical Analysis of Effects of Bank Mergers and Acquisitions on Small Business Lending in Nigeria

    NASA Astrophysics Data System (ADS)

    Ita, Asuquo Akabom

    2012-11-01

    Mergers and acquisitions are the major instruments of the recent banking reforms in Nigeria.The effects and the implications of the reforms on the lending practices of merged banks to small businesses were considered in this study. These effects were divided into static and dynamic effects (restructuring, direct and external). Data were collected by cross-sectional research design and were subsequently analyzed by the ordinary least square (OLS) method.The analyses show that bank size, financial characteristics and deposit of non-merged banks are positively related to small business lending. While for the merged banks, the reverse is the case. From the above result, it is evident that merger and acquisition have not only static effect on small business lending but also dynamic effect, therefore, given the central position of small businesses in the current government policy on industrialization in Nigeria, policy makers in Nigeria, should consider both the static and dynamic effects of merger and acquisition on small business lending in their policy thrust.

  9. Direct formation of small Cu2O nanocubes, octahedra, and octapods for efficient synthesis of triazoles

    NASA Astrophysics Data System (ADS)

    Tsai, Ya-Huei; Chanda, Kaushik; Chu, Yi-Ting; Chiu, Chun-Ya; Huang, Michael H.

    2014-07-01

    In most studies describing the preparation of Cu2O crystals of various morphologies, the particle sizes are normally hundreds of nanometers to micrometers due to rapid particle growth, so they are not exactly nanocrystals. Here we report surfactant-free formation of sub-100 nm Cu2O nanocrystals with systematic shape evolution from cubic to octahedral structures by preparing an aqueous mixture of Cu(OAc)2, NaOH, and N2H4 solution. Adjustment of the hydrazine volume enables the particle shape control. Uniform nanocubes and octahedra were synthesized with edge lengths of 37 and 67 nm, respectively. Novel Cu2O octapods with an edge length of 135 nm were also produced by mixing CuCl2 solution, SDS surfactant, NaOH solution, and NH2OH.HCl reductant solution. All of them are nearly the smallest Cu2O nanocrystals of the same shapes ever reported. These small cubes, octahedra, and octapods were employed as catalysts in the direct synthesis of 1,2,3-triazoles from the reaction of alkynes, organic halides, and NaN3 at 55 °C. All of them displayed high product yields in short reaction times. The octahedra enclosed by the {111} facets are the best catalysts, and can catalyze this cycloaddition reaction with high yields in just 2 h when different alkynes were used to make diverse triazole products. Hence, the small Cu2O particles provide time-saving, energy-efficient, and high product yield benefits to organocatalysis.In most studies describing the preparation of Cu2O crystals of various morphologies, the particle sizes are normally hundreds of nanometers to micrometers due to rapid particle growth, so they are not exactly nanocrystals. Here we report surfactant-free formation of sub-100 nm Cu2O nanocrystals with systematic shape evolution from cubic to octahedral structures by preparing an aqueous mixture of Cu(OAc)2, NaOH, and N2H4 solution. Adjustment of the hydrazine volume enables the particle shape control. Uniform nanocubes and octahedra were synthesized with edge lengths of 37 and 67 nm, respectively. Novel Cu2O octapods with an edge length of 135 nm were also produced by mixing CuCl2 solution, SDS surfactant, NaOH solution, and NH2OH.HCl reductant solution. All of them are nearly the smallest Cu2O nanocrystals of the same shapes ever reported. These small cubes, octahedra, and octapods were employed as catalysts in the direct synthesis of 1,2,3-triazoles from the reaction of alkynes, organic halides, and NaN3 at 55 °C. All of them displayed high product yields in short reaction times. The octahedra enclosed by the {111} facets are the best catalysts, and can catalyze this cycloaddition reaction with high yields in just 2 h when different alkynes were used to make diverse triazole products. Hence, the small Cu2O particles provide time-saving, energy-efficient, and high product yield benefits to organocatalysis. Electronic supplementary information (ESI) available: SEM images of Cu2O nanocrystals with shape evolution, XRD patterns, calculations for the determination of volumes needed for the catalysis experiment, spectral characterization of the triazole products synthesized and their NMR spectra. See DOI: 10.1039/c4nr02076f

  10. Direct mechanical effects of wind on crops

    Microsoft Academic Search

    H. A. Cleugh; J. M. Miller; M. Böhm

    1998-01-01

    This review describes those mechanisms by which wind directly affects crop growth rates and hence yields. Wind-induced plant\\u000a movement is capable of altering growth rates and leaf morphology, although this is unlikely to be a major cause of growth\\u000a differences between sheltered and unsheltered crops grown outdoors. The wind's force can tear leaves or strip them from the\\u000a plant. Dense

  11. Direct formation of small Cu2O nanocubes, octahedra, and octapods for efficient synthesis of triazoles.

    PubMed

    Tsai, Ya-Huei; Chanda, Kaushik; Chu, Yi-Ting; Chiu, Chun-Ya; Huang, Michael H

    2014-08-01

    In most studies describing the preparation of Cu2O crystals of various morphologies, the particle sizes are normally hundreds of nanometers to micrometers due to rapid particle growth, so they are not exactly nanocrystals. Here we report surfactant-free formation of sub-100 nm Cu2O nanocrystals with systematic shape evolution from cubic to octahedral structures by preparing an aqueous mixture of Cu(OAc)2, NaOH, and N2H4 solution. Adjustment of the hydrazine volume enables the particle shape control. Uniform nanocubes and octahedra were synthesized with edge lengths of 37 and 67 nm, respectively. Novel Cu2O octapods with an edge length of 135 nm were also produced by mixing CuCl2 solution, SDS surfactant, NaOH solution, and NH2OH · HCl reductant solution. All of them are nearly the smallest Cu2O nanocrystals of the same shapes ever reported. These small cubes, octahedra, and octapods were employed as catalysts in the direct synthesis of 1,2,3-triazoles from the reaction of alkynes, organic halides, and NaN3 at 55 °C. All of them displayed high product yields in short reaction times. The octahedra enclosed by the {111} facets are the best catalysts, and can catalyze this cycloaddition reaction with high yields in just 2 h when different alkynes were used to make diverse triazole products. Hence, the small Cu2O particles provide time-saving, energy-efficient, and high product yield benefits to organocatalysis. PMID:24947435

  12. USING THE GMI EFFECT FOR DETECTING SMALL ROTATIONAL MOVEMENTS

    Microsoft Academic Search

    Cristian Fosalau; Emil Vremera; Marinel Temneanu; Mihai Cretu

    The paper goal is to describe the way in which the Giant Magnetoimpedance Effect (GMI) occurring in the magnetic amorphous wires can be utilized to detect small rotational movements. The operation principle is based on modification of the wire impedance under action of a torsional stress when an ac low current flows through it. The schematic overview of an angle

  13. The Small Scale Integrated Sachs-Wolfe Effect

    E-print Network

    Wayne Hu; Naoshi Sugiyama

    1993-10-26

    The integrated Sachs-Wolfe effect (ISW) can be an important factor in the generation of Cosmic Microwave Background anisotropies on all scales, especially in a reionized curvature or lambda dominated universe. We present an analytic treatment of the ISW effect, which is analogous to thick last scattering surface techniques for the Doppler effect, that compares quite well with the full numerical calculations. The power spectrum of temperature fluctuations due to the small scale ISW effect has wave number dependence k^{-5} times that of the matter power spectrum.

  14. Subcortical effects of transcranial direct current stimulation in the rat

    PubMed Central

    Bolzoni, F; B?czyk, M; Jankowska, E

    2013-01-01

    Transcranial direct current stimulation (tDCS) affects neurons at both cortical and subcortical levels. The subcortical effects involve several descending motor systems but appeared to be relatively weak, as only small increases in the amplitude of subcortically initiated descending volleys and a minute shortening of latencies of these volleys were found. The aim of the present study was therefore to evaluate the consequences of facilitation of these volleys on the ensuing muscle activation. The experiments were carried out on deeply anaesthetized rats without neuromuscular blockade. Effects of tDCS were tested on EMG potentials recorded from neck muscles evoked by weak (20–60 ?A) single, double or triple stimuli applied in the medial longitudinal fascicle (MLF) or in the red nucleus (RN). Short latencies of these potentials were compatible with monosynaptic or disynaptic actions of reticulospinal and disynaptic or trisynaptic actions of rubrospinal neurons on neck motoneurons. Despite only weak effects on indirect descending volleys, the EMG responses from both the MLF and the RN were potently facilitated by cathodal tDCS and depressed by anodal tDCS. Both the facilitation and the depression developed relatively rapidly (within the first minute) but both outlasted tDCS and were present for up to 1 h after tDCS. The study thus demonstrates long-lasting effects of tDCS on subcortical neurons in the rat, albeit evoked by an opposite polarity of tDCS to that found to be effective on subcortical neurons in the cat investigated in the preceding study, or for cortical neurons in the humans. PMID:23774279

  15. Small Reactor Designs Suitable for Direct Nuclear Thermal Propulsion: Interim Report

    SciTech Connect

    Bruce G. Schnitzler

    2012-01-01

    Advancement of U.S. scientific, security, and economic interests requires high performance propulsion systems to support missions beyond low Earth orbit. A robust space exploration program will include robotic outer planet and crewed missions to a variety of destinations including the moon, near Earth objects, and eventually Mars. Past studies, in particular those in support of both the Strategic Defense Initiative (SDI) and the Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. In NASA's recent Mars Design Reference Architecture (DRA) 5.0 study, nuclear thermal propulsion (NTP) was again selected over chemical propulsion as the preferred in-space transportation system option for the human exploration of Mars because of its high thrust and high specific impulse ({approx}900 s) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit. The recently announced national space policy2 supports the development and use of space nuclear power systems where such systems safely enable or significantly enhance space exploration or operational capabilities. An extensive nuclear thermal rocket technology development effort was conducted under the Rover/NERVA, GE-710 and ANL nuclear rocket programs (1955-1973). Both graphite and refractory metal alloy fuel types were pursued. The primary and significantly larger Rover/NERVA program focused on graphite type fuels. Research, development, and testing of high temperature graphite fuels was conducted. Reactors and engines employing these fuels were designed, built, and ground tested. The GE-710 and ANL programs focused on an alternative ceramic-metallic 'cermet' fuel type consisting of UO2 (or UN) fuel embedded in a refractory metal matrix such as tungsten. The General Electric program examined closed loop concepts for space or terrestrial applications as well as open loop systems for direct nuclear thermal propulsion. Although a number of fast spectrum reactor and engine designs suitable for direct nuclear thermal propulsion were proposed and designed, none were built. This report summarizes status results of evaluations of small nuclear reactor designs suitable for direct nuclear thermal propulsion.

  16. Effects of Foreign Direct Investment (FDI) in the Indian Economy

    E-print Network

    Paris-Sud XI, Université de

    1 Effects of Foreign Direct Investment (FDI) in the Indian Economy Sourangsu Banerji Visiting study the effects of Foreign Direct Investment (FDI) with respect to India and its economy. We try interest (10 percent or more of voting stock) in an enterprise operating in an economy other than

  17. First report of a direct surface plasmon resonance immunosensor for a small molecule seafood toxin.

    PubMed

    Yakes, Betsy Jean; Kanyuck, Kelsey M; DeGrasse, Stacey L

    2014-09-16

    Tetrodotoxin (TTX), a small molecular weight neurotoxin, is responsible for poisoning events that traditionally occur from consumption of contaminated puffer fish. Recent studies have shown a growing number of foods contaminated with TTX and a larger number of waters and associated countries where the toxin may occur. The apparent expanding prevalence of TTX supports a growing need for screening assays that can be used to detect potentially harmful food. In the past few years, surface plasmon resonance (SPR) biosensors have been developed for rapid, robust detection of TTX; however, these assays focus on detection of unbound antibody from an inhibition reaction with the toxin. This manuscript introduces the first direct immunoassay for a seafood toxin, specifically TTX. Major advantages of this assay compared to indirect assays include increased speed of analysis, decreased use of biological reagents, and improved confidence in the detection of the toxin, along with the ability to characterize the antibody/toxin interaction. The analytical method introduced in this paper could be applied to other seafood toxins, as well as to a wide range of low molecular weight targets. PMID:25117539

  18. Progress in Small-scale Studies of Direct Ocean Sequestration of Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Peltzer, E. T.; Brewer, P. G.; Walz, P. M.; White, S. N.

    2002-12-01

    Ocean sequestration of carbon dioxide was first proposed by Marchetti in 1977. The vast size and alkaline capacity of the ocean already exerts a fundamental control on atmospheric CO2 levels, and gas exchange across the air-sea interface of fossil fuel CO2 is now approximately 20 million tons per day globally. Thus direct ocean CO2 injection may be regarded as simply bypassing the atmospheric disposal step with its attendant impact on climate. Beginning in 1997, we have carried out a series of small-scale controlled experimental releases, now ranging from a few hundred meters depth to over 3600m deep, to test geochemical outcomes and biological impacts. These experiments were designed to mimic many of the proposed protocols, including dissolution of a rising bubble, or droplet, plume, formation of a sinking plume, formation and ultimate dissolution of a hydrate, and pooling of CO2 on the ocean floor. By carrying out small-scale experiments, we are able to produce fundamental data on behavior in real dynamic systems, while minimizing biological impacts. We have devised new techniques and procedures for safe handling of multi-liter quantities of liquid CO2 using an ROV, delivering it to the deep-sea and observing its behavior, and for making quantitative measurements. Measurements of CO2 gas, liquid, and hydrate dissolution rates are all consistent with a saturated boundary layer model, with the solubility of CO2 (0.5-1 molar at depth) and the thickness of the boundary layer as primary controls. The rates observed typically fall in the range of a few micromoles/cm2/sec. This allows us to make important predictions of the fate of secondary contaminant species that may be included in industrial systems. However, we have observed significant inconsistencies in the dynamic behavior of liquid CO2 systems, with the occasional abrupt onset of rapid and massive hydrate formation. This stochastic behavior is manifested as a self-generated density driven fluid dynamic instability. Examples include rapid formation of hydrate, with fluid overflow, in a beaker placed on the sea floor, versus quiescent behavior in a repeat experiment; sediment penetration by CO2 with formation of a "frost heave" of hydrate, versus quiescent behavior in an adjoining near-identical study; and rapid formation of hydrate on an inserted electrode tip, versus simple dissolution of CO2 into the water phase in a companion experiment. The characteristic conditions for the abrupt onset of rapid and massive hydrate formation with its attendant instabilities is currently under investigation. We have also observed the formation of plumes of lowered pH around the various experimental sites consistent with the tidal period and velocities. A pH as low as 3.5 was observed for a small protected pocket of seawater exposed to liquid CO2 for 12-15 minutes at 3600m, however the pH quickly returned to the background value of 7.6 a short distance away from the pool. These pH measurements are being reconciled with direct CO2 observations. We anticipate that the pH downstream from a CO2 release will be a complex interplay of the amount released, the exposed area, the bottom current velocity, the extent of turbulent mixing and time. New techniques, including in situ laser Raman spectrometry, have been developed to investigate these processes.

  19. A study of some effects of urbanization on storm runoff from a small watershed

    USGS Publications Warehouse

    Espey, William Howard, Jr.; Morgan, Carl W.; Masch, Frank D.

    1966-01-01

    The evaluation of the effects of urbanization on the runoff characteristics of a small watershed is a problem that can be studied by either a short-range or a long-range investigation. Because the long-range type of investigation would require several years for hydrologic data accumulation, it cannot provide any immediate information on the changes in watershed behavior arising as a result of urbanization. A short-range investigation, however, based on synthetic evaluation of present data would provide immediate answers. It is in the realm of this short-range objective that this study of a small urban watershed is directed.

  20. Reconstructing our Interstellar Past: A Look at the Small Scale Structure in the Direction of the Historical Solar Trajectory

    NASA Astrophysics Data System (ADS)

    Redfield, S.; Scalo, J.; Smith, D. S.

    2007-07-01

    The properties of our nearby interstellar medium (NISM) out to ˜500 pc, including density, temperature, and velocity, provide a sample of the range and timing of environments that have been encountered by our solar system. These conditions influence the structure of the heliosphere, which modulates the flux of Galactic cosmic rays and interstellar gas and dust that reach the Earth. There is a long tradition of speculation focused on the effects of the ISM on heliospheric modulation of cosmic rays and interstellar hydrogen on atmospheric chemistry, cloud cover, glaciation episodes, and exogenous mutation, but the intensity and timing of such variations has never been established empirically, even in a statistical sense. The present work is aimed at evaluating the impact of small scale low column density structures in the NISM, using analysis of absorption line features toward early type stars, on the intensity and timing of heliospheric variations, and at placing these structures, invisible by most other techniques of tracing interstellar structure, in the overall dynamics of the interstellar medium. We present high spectral resolution observations of 49 stars within 10 degrees of the direction of the historical solar trajectory. This densely packed collection of sightlines provides an opportunity to (1) study small-scale structure in the shell separating the Local Bubble from the more distant NISM, (2) enable a rough reconstruction of the interstellar density profile, and hence cosmic ray flux history, encountered by the Solar System in the past 40 million years, and (3) clarify the prevalence of small column density fluctuations in the NISM.

  1. When small losses do not loom larger than small gains: effects of contextual autonomy support and goal contents on behavioural responses to small losses and small gains.

    PubMed

    Chatzisarantis, Nikos L D; Kee, Ying Hwa; Thaung, Hannah Kyaw; Hagger, Martin S

    2012-12-01

    Based on the tenets of self-determination theory, the present studies examined the moderating effects of interpersonal contexts or goal conditions that afforded satisfaction of psychological needs on loss aversion effects. We hypothesized that behavioural responses to small losses would be stronger relative to behavioural responses to small gains under goal conditions or interpersonal contexts that did not support psychological needs. We also expected the effect to be minimized under goal conditions or interpersonal contexts that supported psychological needs. This prediction was supported in Study 1 that induced satisfaction of psychological needs via manipulations of interpersonal context and in Study 2 that instigated satisfaction of psychological needs via manipulations of goal contents. In addition, Studies 1 and 2 demonstrated that psychological needs reduced the classic loss aversion effect by increasing behavioural and affective responses to gains and not because psychological needs altered affective or behavioural responses to losses. Results of the present studies support the conclusion that contextual autonomy support and the distinction between intrinsic and extrinsic goals proposed by self-determination theory define a boundary condition of the loss aversion hypothesis. PMID:21689116

  2. Effects of ethanol on small engines and the environment

    SciTech Connect

    Bettis, M.D.

    1995-01-09

    With the support of the Missouri Corn Merchandising Council and the Department of Energy, Northwest Missouri State University conducted an applied research project to investigate the effects of the commercially available ethanol/gasoline fuel blend on small engines. The study attempted to identify any problems when using the 10% ethanol/gasoline blend in engines designed for gasoline and provide solutions to the problems identified. Fuel economy, maximum power, internal component wear, exhaust emissions and engine efficiency were studied.

  3. Small-scale magnetic buoyancy and magnetic pumping effects in a turbulent convection

    E-print Network

    I. Rogachevskii; N. Kleeorin

    2006-05-18

    We determine the nonlinear drift velocities of the mean magnetic field and nonlinear turbulent magnetic diffusion in a turbulent convection. We show that the nonlinear drift velocities are caused by the three kinds of the inhomogeneities, i.e., inhomogeneous turbulence; the nonuniform fluid density and the nonuniform turbulent heat flux. The inhomogeneous turbulence results in the well-known turbulent diamagnetic and paramagnetic velocities. The nonlinear drift velocities of the mean magnetic field cause the small-scale magnetic buoyancy and magnetic pumping effects in the turbulent convection. These phenomena are different from the large-scale magnetic buoyancy and magnetic pumping effects which are due to the effect of the mean magnetic field on the large-scale density stratified fluid flow. The small-scale magnetic buoyancy and magnetic pumping can be stronger than these large-scale effects when the mean magnetic field is smaller than the equipartition field. We discuss the small-scale magnetic buoyancy and magnetic pumping effects in the context of the solar and stellar turbulent convection. We demonstrate also that the nonlinear turbulent magnetic diffusion in the turbulent convection is anisotropic even for a weak mean magnetic field. In particular, it is enhanced in the radial direction. The magnetic fluctuations due to the small-scale dynamo increase the turbulent magnetic diffusion of the toroidal component of the mean magnetic field, while they do not affect the turbulent magnetic diffusion of the poloidal field.

  4. The capsid of small papova viruses contains 72 pentameric capsomeres: direct evidence from cryo-electron-microscopy

    E-print Network

    Baker, Timothy S.

    The capsid of small papova viruses contains 72 pentameric capsomeres: direct evidence from cryo-electron structures: image analysis of electron micrographs of frozen- hydrated samples (SV40 virions from cryo-electron microscopy supports the correctness of the polyoma structure solved

  5. The Determinants of the Location of Foreign Direct Investment by Japanese Small and Medium-sized Enterprises

    Microsoft Academic Search

    Shujiro Urata; Hiroki Kawai

    2000-01-01

    Japanese manufacturing small and medium enterprises (SMEs) have actively undertaken Foreign Direct Investment (FDI) in Asia since the mid-1980s. FDI contributes to economic growth of the FDI recipient countries, as it brings in not only financial resources for investment but also technologies and managerial know-how, which are important factors for promoting economic growth. Recognizing these benefits of receiving FDI, policy

  6. EFFECTS OF ELECTRICAL STIMULATION AND OF DIRECT CURRENT AND HIGH

    E-print Network

    Paris-Sud XI, Université de

    EFFECTS OF ELECTRICAL STIMULATION AND OF DIRECT CURRENT AND HIGH FREQUENCY LESIONS to either electrical stimulation (AC), direct current (DC) lesions, high frequency (HF) lesions or to sham or purely electrical stimulation with alternating current (AC) of the hypothalamus may advance vaginal

  7. Effects of Direct and Indirect Praise and Blame on Attribution

    Microsoft Academic Search

    Rabindra N. Kanungo; Leonard Norman

    1974-01-01

    The effects of direct and indirect praise and blame on correspondence of inference were examined in a minimal social interaction setting involving female triads. Two measures of correspondence of inference—trait ratings and confidence ratings—were used. Results indicated that (a) correspondence of inference about an actor is greater when the actor praises rather than blames, and (b) a person more directly

  8. CellFateScout – a bioinformatics tool for elucidating small molecule signaling pathways that drive cells in a specific direction

    PubMed Central

    2013-01-01

    Background Small molecule effects can be represented by active signaling pathways within functional networks. Identifying these can help to design new strategies to utilize known small molecules, e.g. to trigger specific cellular transformations or to reposition known drugs. Results We developed CellFateScout that uses the method of Latent Variables to turn differential high-throughput expression data and a functional network into a list of active signaling pathways. Applying it to Connectivity Map data, i.e., differential expression data describing small molecule effects, we then generated a Human Small Molecule Mechanisms Database. Finally, using a list of active signaling pathways as query, a similarity search can identify small molecules from the database that may trigger these pathways. We validated our approach systematically, using expression data of small molecule perturbations, yielding better predictions than popular bioinformatics tools. Conclusions CellFateScout can be used to select small molecules for their desired effects. The CellFateScout Cytoscape plugin, a tutorial and the Human Small Molecule Mechanisms Database are available at https://sourceforge.net/projects/cellfatescout/ under LGPLv2 license. PMID:24206562

  9. Strong piezoresistance effect of small molecule organic semiconductors

    NASA Astrophysics Data System (ADS)

    Zhong, Gao-Yu; Liu, Yu; Song, Jia; Zhao, Qing; Li, Yue-Sheng; Li, Fu-You

    2008-10-01

    In this paper, we report on the strong piezoresistance effect on small molecule organic semiconductors. We fabricated and measured the indium-tin-oxide (ITO)/tris- (8-hydroxyquinoline) aluminium (Alq, 80 nm) (or bathocuproine (BCP, 70 nm))/Al devices. In the simple devices, we measured the current under constant bias and square wave pulses with a load-produced varying pressure applied on the devices. The current shows a high sensitivity to the pressure. The related mechanism is also discussed. Our results clearly demonstrate that some of the small molecule organic semiconductors show potential as sensitive materials to be used in a tactile sensor. The sensor could be used in an artificial 'electronic skin' for future robots used in daily life for housekeeping or entertainment purposes.

  10. Small-scale experiments in STOVL ground effects

    NASA Technical Reports Server (NTRS)

    Corsiglia, Victor R.; Wardwell, Douglas A.; Kuhn, Richard E.

    1991-01-01

    A series of tests was completed in which suckdown and fountain forces and pressures were measured on circular plates and twin-tandem-jet generic STOVL (short takeoff and vertical landing) configurations. The tests were conducted using a small-scale hover rig, for jet pressure ratios up to 6 and jet temperatures up to 700 F. The measured suckdown force on a circular plate with a central jet was greater than that found with a commonly used empirical prediction method. The present data showed better agreement with other sets of data. The tests of the generic STOVL configurations were conducted to provide force and pressure data with a parametric variation of parameters so that an empirical prediction method could be developed. The effects of jet pressure ratio and temperature were found to be small. Lift improvement devices were shown to substantially reduce the net suckdown forces.

  11. Small-scale experiments in STOVL ground effects

    NASA Technical Reports Server (NTRS)

    Corsiglia, Victor R.; Wardwell, Douglas A.; Kuhn, Richard E.

    1990-01-01

    A series of tests has been completed in which suckdown and fountain forces and pressures were measured on circular plates and twin-tandem-jet generic STOVL (short takeoff and vertical landing) configurations. The tests were conducted using a small-scale hover rig, for jet pressure ratios up to 6 and jet temperatures up to 700 F. The measured suckdown force on a circular plate with a central jet was greater than that found with a commonly used empirical prediction method. The present data showed better agreement with other sets of data. The tests of the generic STOVL configurations were conducted to provide force and pressure data with a parametric variation of parameters so that an empirical prediction method cold be developed. The effects of jet pressure ratio and temperature were found to be small. Lift improvement devices were shown to substantially reduce the net suckdown forces.

  12. Effects of Bariatric Surgery on Human Small Artery Function

    PubMed Central

    Aghamohammadzadeh, Reza; Greenstein, Adam S.; Yadav, Rahul; Jeziorska, Maria; Hama, Salam; Soltani, Fardad; Pemberton, Phil W.; Ammori, Basil; Malik, Rayaz A.; Soran, Handrean; Heagerty, Anthony M.

    2013-01-01

    Objectives The aim of this study was to investigate the effects of bariatric surgery on small artery function and the mechanisms underlying this. Background In lean healthy humans, perivascular adipose tissue (PVAT) exerts an anticontractile effect on adjacent small arteries, but this is lost in obesity-associated conditions such as the metabolic syndrome and type II diabetes where there is evidence of adipocyte inflammation and increased oxidative stress. Methods Segments of small subcutaneous artery and perivascular fat were harvested from severely obese individuals before (n = 20) and 6 months after bariatric surgery (n = 15). Small artery contractile function was examined in vitro with wire myography, and perivascular adipose tissue (PVAT) morphology was assessed with immunohistochemistry. Results The anticontractile activity of PVAT was lost in obese patients before surgery when compared with healthy volunteers and was restored 6 months after bariatric surgery. In vitro protocols with superoxide dismutase and catalase rescued PVAT anticontractile function in tissue from obese individuals before surgery. The improvement in anticontractile function after surgery was accompanied by improvements in insulin sensitivity, serum glycemic indexes, inflammatory cytokines, adipokine profile, and systolic blood pressure together with increased PVAT adiponectin and nitric oxide bioavailability and reduced macrophage infiltration and inflammation. These changes were observed despite the patients remaining severely obese. Conclusions Bariatric surgery and its attendant improvements in weight, blood pressure, inflammation, and metabolism collectively reverse the obesity-induced alteration to PVAT anticontractile function. This reversal is attributable to reductions in local adipose inflammation and oxidative stress with improved adiponectin and nitric oxide bioavailability. PMID:23665100

  13. Extraction of Network Topology From Multi-Electrode Recordings: Is there a Small-World Effect?

    PubMed Central

    Gerhard, Felipe; Pipa, Gordon; Lima, Bruss; Neuenschwander, Sergio; Gerstner, Wulfram

    2011-01-01

    The simultaneous recording of the activity of many neurons poses challenges for multivariate data analysis. Here, we propose a general scheme of reconstruction of the functional network from spike train recordings. Effective, causal interactions are estimated by fitting generalized linear models on the neural responses, incorporating effects of the neurons’ self-history, of input from other neurons in the recorded network and of modulation by an external stimulus. The coupling terms arising from synaptic input can be transformed by thresholding into a binary connectivity matrix which is directed. Each link between two neurons represents a causal influence from one neuron to the other, given the observation of all other neurons from the population. The resulting graph is analyzed with respect to small-world and scale-free properties using quantitative measures for directed networks. Such graph-theoretic analyses have been performed on many complex dynamic networks, including the connectivity structure between different brain areas. Only few studies have attempted to look at the structure of cortical neural networks on the level of individual neurons. Here, using multi-electrode recordings from the visual system of the awake monkey, we find that cortical networks lack scale-free behavior, but show a small, but significant small-world structure. Assuming a simple distance-dependent probabilistic wiring between neurons, we find that this connectivity structure can account for all of the networks’ observed small-world ness. Moreover, for multi-electrode recordings the sampling of neurons is not uniform across the population. We show that the small-world-ness obtained by such a localized sub-sampling overestimates the strength of the true small-world structure of the network. This bias is likely to be present in all previous experiments based on multi-electrode recordings. PMID:21344015

  14. Analytical fuel property effects: Small combustors, phase 2

    NASA Technical Reports Server (NTRS)

    Hill, T. G.; Monty, J. D.; Morton, H. L.

    1985-01-01

    The effects of non-standard aviation fuels on a typical small gas turbine combustor were studied and the effectiveness of design changes intended to counter the effects of these fuels was evaluated. The T700/CT7 turboprop engine family was chosen as being representative of the class of aircraft power plants desired for this study. Fuel properties, as specified by NASA, are characterized by low hydrogen content and high aromatics levels. No. 2 diesel fuel was also evaluated in this program. Results demonstrated the anticipated higher than normal smoke output and flame radiation intensity with resulting increased metal temperatures on the baseline T700 combustor. Three new designs were evaluated using the non standard fuels. The three designs incorporated enhanced cooling features and smoke reduction features. All three designs, when burning the broad specification fuels, exhibited metal temperatures at or below the baseline combustor temperatures on JP-5. Smoke levels were acceptable but higher than predicted.

  15. A Small Stem Loop Element Directs Internal Initiation of the URE2 Internal Ribosome Entry Site in Saccharomyces cerevisiae*

    PubMed Central

    Reineke, Lucas C.; Komar, Anton A.; Caprara, Mark G.; Merrick, William C.

    2008-01-01

    Internal initiation of translation is the process of beginning protein synthesis independent of the m7G cap structure at the 5?-end of an mRNA molecule. We have previously shown that the URE2 mRNA in the yeast Saccharomyces cerevisiae contains an internal ribosome entry site (IRES) whose activity is suppressed by eukaryotic initiation factor 2A (eIF2A; YGR054W). In this study, the minimal sequence required to efficiently direct internal initiation was determined using a system that abrogates cap-dependent scanning of the 40 S ribosomal subunit in both wild-type and eIF2A knock-out cells. Subsequently, secondary structural elements within the minimal sequence were determined by probing with RNases T1 and V1 and the small molecule diethylpyrocarbonate. It was found that the URE2 minimal IRES comprises a 104 nucleotide A-rich stem loop element encompassing the internal AUG codon. Interestingly, the internal AUG seems to be involved in base-pairing interactions that would theoretically hamper its ability to interact with incoming initiator tRNA molecules. Furthermore, none of the truncations used to identify the minimal IRES element were capable of abrogating the suppressive effect of eIF2A. Our data provide the first insight into the RNA structural requirements of the yeast translational machinery for cap-independent initiation of protein synthesis. PMID:18460470

  16. Observations of aerosol semi-direct effects at multiple scales

    NASA Astrophysics Data System (ADS)

    Wilcox, E. M.

    2013-05-01

    The semi-direct radiative forcing of absorbing aerosols such as soot and smoke is generally regarded as a positive forcing whereby tropospheric heating owing to aerosol absorption of sunlight reduces cloud cover. The responses of cloud systems to tropospheric heating, however, may be more varied depending upon the vertical and geographic relationship between the aerosol direct forcing and the clouds, as well as depending upon the scales of the cloud systems. This presentation will explore techniques for applying satellite and in-situ observations to the diagnosis of semi-direct effects on cloud systems ranging from trade cumulus clouds to the inter-tropical convergence zone. Examples are shown of semi-direct effects yielding a negative radiative forcing, as well as large-scale shifts of cloud and precipitation patterns. These studies seek to evaluate the results of controlled model experiments where the radiative effects of aerosols are isolated from other modifications to the environment that influence cloud systems.

  17. Radiotherapy in Small-Cell Lung Cancer: Lessons Learned and Future Directions

    SciTech Connect

    Slotman, Ben J., E-mail: bj.slotman@vumc.n [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Senan, Suresh [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands)

    2011-03-15

    Although chemotherapy is an essential component in the treatment of small-cell lung cancer, improvements in survival in the past two decades have been mainly achieved by the appropriate application of radiotherapy. The aim of the present study was to review the key developments in thoracic radiotherapy and prophylactic cranial radiotherapy and to discuss the rationale behind key ongoing studies in small-cell lung cancer.

  18. Small Fast Spectrum Reactor Designs Suitable for Direct Nuclear Thermal Propulsion

    SciTech Connect

    Bruce G. Schnitzler; Stanley K. Borowski

    2012-07-01

    Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. Past studies, in particular those in support of both the Strategic Defense Initiative (SDI) and Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. The recent NASA Design Reference Architecture (DRA) 5.0 Study re-examined mission, payload, and transportation system requirements for a human Mars landing mission in the post-2030 timeframe. Nuclear thermal propulsion was again identified as the preferred in-space transportation system. A common nuclear thermal propulsion stage with three 25,000-lbf thrust engines was used for all primary mission maneuvers. Moderately lower thrust engines may also have important roles. In particular, lower thrust engine designs demonstrating the critical technologies that are directly extensible to other thrust levels are attractive from a ground testing perspective. An extensive nuclear thermal rocket technology development effort was conducted from 1955-1973 under the Rover/NERVA Program. Both graphite and refractory metal alloy fuel types were pursued. Reactors and engines employing graphite based fuels were designed, built and ground tested. A number of fast spectrum reactor and engine designs employing refractory metal alloy fuel types were proposed and designed, but none were built. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art graphite based fuel design incorporating lessons learned from the very successful technology development program. The SNRE was a nominal 16,000-lbf thrust engine originally intended for unmanned applications with relatively short engine operations and the engine and stage design were constrained to fit within the payload volume of the then planned space shuttle. The SNRE core design utilized hexagonal fuel elements and hexagonal structural support elements. The total number of elements can be varied to achieve engine designs of higher or lower thrust levels. Some variation in the ratio of fuel elements to structural elements is also possible. Options for SNRE-based engine designs in the 25,000-lbf thrust range were described in a recent (2010) Joint Propulsion Conference paper. The reported designs met or exceeded the performance characteristics baselined in the DRA 5.0 Study. Lower thrust SNRE-based designs were also described in a recent (2011) Joint Propulsion Conference paper. Recent activities have included parallel evaluation and design efforts on fast spectrum engines employing refractory metal alloy fuels. These efforts include evaluation of both heritage designs from the Argonne National Laboratory (ANL) and General Electric Company GE-710 Programs as well as more recent designs. Results are presented for a number of not-yet optimized fast spectrum engine options.

  19. Changing effects of direct-to-consumer broadcast drug advertising information sources on prescription drug requests.

    PubMed

    Lee, Annisa Lai

    2009-06-01

    This study tracks the changes of the effects of 4 information sources for direct-to-consumer drug advertising on patients' requests for prescription drugs from physicians since the inception of the "Guidance for Industry about Consumer-directed Broadcast Advertisements." The Guidance advises pharmaceuticals to use four information sources for consumers to seek further information to supplement broadcast drug advertisements: small-print information, the Internet, a toll-free number, and health-care providers (nurses, doctors, and pharmacists). Logistic models were created by using survey data collected by the Food and Drug Administration in 1999 and 2002. Results show that throughout the years, health-care providers remain the most used and strongest means associated with patients' direct requests for nonspecific and specific prescription drugs from doctors. The small-print information source gains power and changes from an indirect means associated with patients' discussing drugs with health-care providers to a direct means associated with patients' asking about nonspecific and specific drugs from their doctors. The Internet is not directly related to drug requests, but the effect of its association with patients seeking information from health-care providers grew 11-fold over the course of the study. The toll-free number lost its power altogether for both direct request for a prescription drug and further discussion with health-care providers. Patient demographics will be considered for specific policy implications. PMID:19499430

  20. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...false Small electric motors energy conservation standards and their effective dates...Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN...EQUIPMENT Small Electric Motors Energy Conservation Standards § 431.446 Small...

  1. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...false Small electric motors energy conservation standards and their effective dates...Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN...EQUIPMENT Small Electric Motors Energy Conservation Standards § 431.446 Small...

  2. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...false Small electric motors energy conservation standards and their effective dates...Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN...EQUIPMENT Small Electric Motors Energy Conservation Standards § 431.446 Small...

  3. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...false Small electric motors energy conservation standards and their effective dates...Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN...EQUIPMENT Small Electric Motors Energy Conservation Standards § 431.446 Small...

  4. SUCCESSIVE SOLAR ERUPTIONS TRIGGERED BY THE COLLISION OF TWO SMALL SUNSPOTS WITH OPPOSITE POLARITIES AND MOTIONAL DIRECTIONS

    SciTech Connect

    Yan, X. L.; Qu, Z. Q.; Kong, D. F. [National Astronomical Observatories/Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China)

    2012-03-15

    We present a study of the two successive M-class flares associated with two coronal mass ejections (CMEs) triggered by the collision of two small sunspots with opposite magnetic polarities and motional directions in NOAA active region (AR) 10484 on 2003 October 22. From the evolution of this AR in the TRACE white-light images and 96 minute line-of-sight magnetograms observed by the Michelson Doppler Imager on board SOHO, a large sunspot and a small sunspot with negative polarity rotated clockwise about 33 Degree-Sign and 18 Degree-Sign , respectively, from the northeast of a quiescent sunspot with negative polarity to the southeast from 15:00 UT on October 21 to 16:24 UT on October 23. During the process of their motion, the small sunspot with negative polarity collided with the small sunspot with positive polarity and opposite motional direction. In the collision, this AR produced two successive M-class flares and CMEs according to the observations of GOES and the Large Angle and Spectrometric Coronagraph. By analyzing the magnetic fields at polarity inversion lines (PILs) between the two small sunspot, it is found that a sudden squeeze occurred near the onset of the two M-class flares and then recovered itself after the flares. We ruled out the emergence of the magnetic fields near the PIL. According to the brightenings in TRACE 1600 A and the hard X-ray sources of the RHESSI of two M-class flares, we found that the locations of the two flares are almost situated in the same location at the PIL between the two small sunspots. We suggest that the sudden squeeze between the opposite magnetic polarities is caused by the pressure of the collision of the two small sunspots and resulted in the magnetic reconnection. These results could contribute to understanding the mechanism of flares and CMEs.

  5. Simple, distance-dependent formulation of the Watts-Strogatz model for directed and undirected small-world networks

    NASA Astrophysics Data System (ADS)

    Song, H. Francis; Wang, Xiao-Jing

    2014-12-01

    Small-world networks—complex networks characterized by a combination of high clustering and short path lengths—are widely studied using the paradigmatic model of Watts and Strogatz (WS). Although the WS model is already quite minimal and intuitive, we describe an alternative formulation of the WS model in terms of a distance-dependent probability of connection that further simplifies, both practically and theoretically, the generation of directed and undirected WS-type small-world networks. In addition to highlighting an essential feature of the WS model that has previously been overlooked, namely the equivalence to a simple distance-dependent model, this alternative formulation makes it possible to derive exact expressions for quantities such as the degree and motif distributions and global clustering coefficient for both directed and undirected networks in terms of model parameters.

  6. Direct extraction of the AlGaAs\\/GaAs heterojunction bipolar transistor small-signal equivalent circuit

    Microsoft Academic Search

    Damian Costa; William U. Liu; James S. Harris

    1991-01-01

    The authors describe a novel, direct technique for determining the small-signal equivalent circuit of a heterojunction bipolar transistor (HBT). The parasitic elements are largely determined from measurements of test structures, reducing the number of elements determined from measurements of the transistor. The intrinsic circuit elements are evaluated from y-parameter data, which are DC-embedded from the known parasitics. The equivalent-circuit elements

  7. Direct observation of stress accumulation and relaxation in small bundles of superconducting vortices in tungsten thin-films

    E-print Network

    I. Guillamon; H. Suderow; S. Vieira; J. Sese; R. Cordoba; J. M. De Teresa; M. R. Ibarra

    2011-01-12

    We study the behavior of bundles of superconducting vortices when increasing the magnetic field using scanning tunneling microscopy and spectroscopy (STM/S) at 100 mK. Pinning centers are given by features on the surface corrugation. We find strong net vortex motion in a bundle towards a well defined direction. We observe continuos changes of the vortex arrangements, and identify small displacements, which stress and deform the vortex bundle, separated by larger re-arrangements or avalanches, which release accumulated stress.

  8. Role of Rebiopsy in Relapsed Non-Small Cell Lung Cancer for Directing Oncology Treatments

    PubMed Central

    Jekunen, Antti P.

    2015-01-01

    Background. Currently, few rebiopsies are performed in relapses of advanced non-small cell lung cancer. They are not customary in clinical practice of lung cancer. However, it is not possible to properly target treatments in cases of relapse without knowing the nature of new lesions. Design. This paper comprehensively summarizes the available literature about rebiopsy and broadly discusses the importance of rebiopsy in advanced non-small cell lung cancer. Results. Altogether 560 abstracts were used as material for further analysis. 19 articles were about clinical rebiopsy in lung cancer and were reviewed in detailed manner. Conclusions. This review shows that rebiopsy is feasible in non-small cell lung cancer, and success rates can be high if rebiopsy is accompanied by adequate evaluation before biopsy. Its use may resolve the difficulties in sampling bias and detecting changes in cancer characteristics. In cases where treatment was selected based on tissue characteristics that then change, the treatment selection process must be repeated while considering new characteristics of the tumor. Rebiopsy may be used to predict therapeutic resistance and consequently redirect targeted therapies. Such knowledge may resolve the difficulties in sampling bias and also in selecting preexisting clones or formulating drug-resistant ones. Rebiopsy should be performed more often in non-small cell lung cancer. PMID:25699082

  9. Driving and Driven Architectures of Directed Small-World Human Brain Functional Networks

    Microsoft Academic Search

    Chaogan Yan; Yong He

    2011-01-01

    Recently, increasing attention has been focused on the investigation of the human brain connectome that describes the patterns of structural and functional connectivity networks of the human brain. Many studies of the human connectome have demonstrated that the brain network follows a small-world topology with an intrinsically cohesive modular structure and includes several network hubs in the medial parietal regions.

  10. Peer Modeling of Academic and Social Behaviors during Small-Group Direct Instruction

    ERIC Educational Resources Information Center

    Ledford, Jennifer R.; Wolery, Mark

    2013-01-01

    The authors describe an intervention for 3 preschoolers with disabilities who had low peer-related social competence. The intervention taught academic skills tailored to the need of each target student in small groups (triads) with two typically developing peers, using a progressive time delay procedure. Prior to instruction and separate from the…

  11. A Direct, Competitive Enzyme-Linked Immunosorbent Assay (ELISA) as a Quantitative Technique for Small Molecules

    ERIC Educational Resources Information Center

    Powers, Jennifer L.; Rippe, Karen Duda; Imarhia, Kelly; Swift, Aileen; Scholten, Melanie; Islam, Naina

    2012-01-01

    ELISA (enzyme-linked immunosorbent assay) is a widely used technique with applications in disease diagnosis, detection of contaminated foods, and screening for drugs of abuse or environmental contaminants. However, published protocols with a focus on quantitative detection of small molecules designed for teaching laboratories are limited. A…

  12. Laser desorption/ionization mass spectrometry for direct profiling and imaging of small molecules from raw biological materials

    SciTech Connect

    Cha, Sangwon

    2008-05-15

    Matrix-assisted laser desorption/ionization(MALDI) mass spectrometry(MS) has been widely used for analysis of biological molecules, especially macromolecules such as proteins. However, MALDI MS has a problem in small molecule (less than 1 kDa) analysis because of the signal saturation by organic matrixes in the low mass region. In imaging MS (IMS), inhomogeneous surface formation due to the co-crystallization process by organic MALDI matrixes limits the spatial resolution of the mass spectral image. Therefore, to make laser desorption/ionization (LDI) MS more suitable for mass spectral profiling and imaging of small molecules directly from raw biological tissues, LDI MS protocols with various alternative assisting materials were developed and applied to many biological systems of interest. Colloidal graphite was used as a matrix for IMS of small molecules for the first time and methodologies for analyses of small metabolites in rat brain tissues, fruits, and plant tissues were developed. With rat brain tissues, the signal enhancement for cerebroside species by colloidal graphite was observed and images of cerebrosides were successfully generated by IMS. In addition, separation of isobaric lipid ions was performed by imaging tandem MS. Directly from Arabidopsis flowers, flavonoids were successfully profiled and heterogeneous distribution of flavonoids in petals was observed for the first time by graphite-assisted LDI(GALDI) IMS.

  13. Effects of mahogany ( Swietenia macrophylla) logging on small mammal communities, habitat structure, and seed predation in the southeastern Amazon Basin

    Microsoft Academic Search

    Thomas D. Lambert; Jay R. Malcolm; Barbara L. Zimmerman

    2005-01-01

    Vast areas of the Amazon have been subjected to low-intensity selective logging for high value timber species such as mahogany (Swietenia macrophylla). Although the ecological consequences of such logging are often assumed to be minimal, few studies have directly tested this assumption. In this paper we examine the effects of various intensities of mahogany logging on small mammal communities, habitat

  14. The effects of RF absorbers on measurements of small antennas in small anechoic chambers

    Microsoft Academic Search

    C. Icheln; J. Ollikainen; P. Vainikainen

    1999-01-01

    In this work the influence of resistive absorbers in the vicinity of small antennas was investigated, in order to define a lower limit for the size of a small anechoic chamber for antenna calibration and radiation pattern measurements, with respect to the distance between the antenna under test (AUT) and the RF absorbers lining the walls. Furthermore, the influence of

  15. Effects of RF absorbers on measurements of small antennas in small anechoic chambers

    Microsoft Academic Search

    C. Icheln; J. Ollikainen; P. Vainikainen

    2001-01-01

    In this work, the influence of resistive absorbers in the vicinity of small antennas was investigated, in order to define a lower limit for the size of a small anechoic chamber for antenna calibration and radiation pattern measurements, with respect to the distance between the antenna under test (AUT) and the RF absorbers lining the walls. Furthermore, the influence of

  16. Rockot - a new cost effective launcher for small satellites

    NASA Astrophysics Data System (ADS)

    Mosenkis, Regina

    1996-01-01

    Daimler-Benz Aerospace of Germany and the Russian Khrunichev State Research and Production Space Center have formed a jointly owned EUROCKOT Launch Services GmbH to offer worldwide cost effective launch services for the ROCKOT launch vehicle. ROCKOT, produced by Khrunichev, builder of the famous PROTON launcher, aims at the market of small and medium size satellites ranging from 300 to 1800 kg to be launched into low earth or sunsynchronous orbits. These comprize scientific, earth observation and polar meteorological satellites as well as the new generation of small communication satellites in low earth orbits, known as the ``Constellations''. ROCKOT is a three stage liquid propellant launch vehicle, composed of a former Russian SS 19 strategic missile, which has been withdrawn from military use, and a highly sophisticated, flight-proven upper stage named Breeze, which is particularly suited for a variety of civic and commercial space applications. Usable payload envelope has a length of 4.75 meters and a maximum diameter of 2.26 meters for accomodating the payload within the payload fairing. ROCKOT can also accomodate multiple payloads which can be deployed into the same or different orbits. So far ROCKOT has been successfully launched three times from Baikonur. The commercial launch services on ROCKOT from the Plesetsk launch site, Russia, will begin in 1997 and will be available worldwide at a highly competitive price.

  17. Catchment scale analysis of the effect of topography, tillage direction and unpaved roads on ephemeral gully incision

    Microsoft Academic Search

    Tal Svoray; Hila Markovitch

    2009-01-01

    High-resolution airphotographs and digital elevation models (DEMs) were used to study areas prone to gully incision in a small agricultural catchment in northern Israel. Data are analyzed to understand better the integrated effect of environmental and human factors on gully incision. The effect of fl ow accumulation, slope, unpaved roads density and tillage direction on gully width and length is

  18. Distinct roles for Argonaute proteins in small RNA-directed RNA cleavage pathways

    Microsoft Academic Search

    Katsutomo Okamura; Akira Ishizuka; Haruhiko Siomi; Mikiko C. Siomi

    2004-01-01

    In mammalian cells, both microRNAs (miRNAs) and small interfering RNAs (siRNAs) are thought to be loaded into the same RNA-induced silencing complex (RISC), where they guide mRNA degradation or translation silencing depending on the complementarity of the target. In Drosophila, Argonaute2 (AGO2) was identified as part of the RISC complex. Here we show that AGO2 is an essential component for

  19. Outward Foreign Direct Investment and Human Capital Development: A Small Country Perspective

    ERIC Educational Resources Information Center

    McDonnell, Anthony

    2008-01-01

    Purpose: The purpose of this paper is to examine the pattern of outward foreign direct investment (FDI) by Irish MNCs, and more specifically, to investigate their approach to human capital development and how these correspond to foreign MNCs in Ireland. In particular, it seeks to investigate training and development expenditure, adoption of…

  20. New Directions in Solar System Small Body Science with the TMT

    NASA Astrophysics Data System (ADS)

    Meech, Karen J.

    2014-07-01

    One of the key goals of the Planetary Science Decadal Survey includes using primitive bodies to provide information about the epochs and processes in the early solar system and to understand the role that primitive bodies played in creating habitable worlds. Recent in-situ small body space missions (EPOXI, NEOWISE) have changed our understanding of the distribution of major volatiles in primitive bodies, in particular shedding light on the importance of CO2. At the same time there has been a revolution both in the dynamical models that describe how our solar system was assembled, and in the chemistry of the disk of material out of which the planetesimals formed. Observations of small bodies provide the links that will enable us to tie together the early solar system dynamical and chemical models. Because they are small and faint, we have been very limited in optical and near-IR spectroscopic follow up. I will present some of the recent breakthroughs, and what access to the TMT can contribute to understanding the early solar system, in combination with information that will be possible to get from JWST and ALMA.

  1. Small effective population size in the long-toed salamander.

    PubMed

    Funk, W C; Tallmon, D A; Allendorf, F W

    1999-10-01

    The effective population sizes (Ne) of six populations of the long-toed salamander (Ambystoma macrodactylum) from Montana and Idaho, USA were estimated from allozyme data from samples collected in 1978, 1996 and 1997 using the temporal allele frequency method. Five of the six estimates ranged from 23 to 207 (mean = 123 +/- 79); one estimate was indistinguishable from infinity. In order to infer the actual Ne of salamander populations, we compared the frequency distribution of our observed Ne estimates with distributions obtained from simulated populations of known Ne. Our observed Ne estimate distribution was consistent with distributions from simulated populations with Ne values of 10, 25, and 50, suggesting an actual Ne for each of the six salamander populations of less than 100. This Ne estimate agrees with most other Ne estimates for amphibians. We conclude by discussing the conservation implications of small Ne values in amphibians in the context of increasing isolation of populations due to habitat fragmentation. PMID:10583827

  2. Analytical fuel property effects, small combustors, phase 1

    NASA Technical Reports Server (NTRS)

    Cohen, J. D.

    1983-01-01

    The effects of nonstandard aviation fuels on a typical small gas turbine combustor was analyzed. The T700/CT7 engine family was chosen as being representative of the class of aircraft power plants desired. Fuel properties, as specified by NASA, are characterized by low hydrogen content and high aromatics levels. Higher than normal smoke output and flame radiation intensity for the current T700 combustor which serves as a baseline were anticipated. It is, therefore, predicted that out of specification smoke visibility and higher than normal shell temperatures will exist when using NASA ERBS fuels with a consequence of severe reduction in cyclic life. Three new designs are proposed to compensate for the deficiencies expected with the existing design. They have emerged as the best of the eight originally proposed redesigns or combinations thereof. After the five choices that were originally made by NASA on the basis of competing performance factors, General Electric narrowed the field to the three proposed.

  3. Small-scale helicity and ? -effect in the Earth's core

    NASA Astrophysics Data System (ADS)

    Shimizu, Hisayoshi; Loper, David E.

    2000-09-01

    It is a commonly held belief that the combination of rotation and buoyancy creates a net helicity and electromotive force (EMF), known as an ? -effect, and hence, dynamo action. We investigate this possibility for a simple, but dynamically complete, model, consisting of a small, isolated buoyant parcel rising in an infinite extent of rotating electrically conducting Boussinesq fluid in the presence of a large-scale magnetic field. We show that the leading order in the local magnetic Reynolds number, assumed small, is that the total helicity and EMF are identically zero, due to symmetry. This is in effect an anti-dynamo theorem, to be overcome if dynamo action is to occur. The helicity and EMF densities are found to be concentrated in wakes having spatial extent much larger than the scale of the buoyant parcel. The wakes are aligned with rotation if Coriolis force dominates Lorentz (forming a foreshortened Taylor column) and with the magnetic field if Lorentz dominates Coriolis. Consequently, the integrals of helicity and EMF over a half-space on either side of the parcel are non-zero. These distributions have the potential of creating wavelike dynamo action as the buoyant parcel rises through the outer core. In the case that the Coriolis force is dominant and the viscous force is very weak, it is found that the half-space integral of helicity is inversely proportional to the square root of the Ekman number. This is a counterintuitive result, depending on the action of a very weak viscous force at very large distance from the buoyant parcel.

  4. An effective method for small event detection: match and locate (M&L)

    NASA Astrophysics Data System (ADS)

    Zhang, Miao; Wen, Lianxing

    2015-03-01

    Detection of low magnitude event is critical and challenging in seismology. We develop a new method, named the match and locate (M&L) method, for small event detection. The M&L method employs some template events and detects small events through stacking cross-correlograms between waveforms of the template events and potential small event signals in the continuous waveforms over multiple stations and components, but the stacking is performed after making relative traveltime corrections based on the relative locations of the template event and potential small event scanning through a 3-D region around the template. Compared to the current methods of small event detection, the M&L method places event detection to a lower magnitude level and extends the capability of detecting small events that have large distance separations from the template. The method has little dependence on the accuracy of the velocity models used, and, at the same time, provides high-precision location information of the detected small-magnitude events. We demonstrate the effectiveness of the M&L method and its advantage over the matched filter method using examples of scaled-down earthquakes occurring in the Japan Island and foreshock detection before the 2011 Mw 9.0 Tohoku earthquake. In the foreshock detection, the M&L method detects four times more events (1427) than the templates and 9 per cent (134) more than the matched filter under the same detection threshold. Up to 41 per cent (580) of the detected events are not located at the template locations with the largest separation of 9.4 km. Based on the identified foreshocks, we observe five sequences of foreshock migration along the trench-parallel direction toward the epicentre of the Mw 9.0 main shock.

  5. Effective dose from direct and indirect digital panoramic units

    PubMed Central

    Lee, Gun-Sun; Kim, Jin-Soo; Seo, Yo-Seob

    2013-01-01

    Purpose This study aimed to provide comparative measurements of the effective dose from direct and indirect digital panoramic units according to phantoms and exposure parameters. Materials and Methods Dose measurements were carried out using a head phantom representing an average man (175 cm tall, 73.5 kg male) and a limbless whole body phantom representing an average woman (155 cm tall, 50 kg female). Lithium fluoride thermoluminescent dosimeter (TLD) chips were used for the dosimeter. Two direct and 2 indirect digital panoramic units were evaluated in this study. Effective doses were derived using 2007 International Commission on Radiological Protection (ICRP) recommendations. Results The effective doses of the 4 digital panoramic units ranged between 8.9 µSv and 37.8 µSv. By using the head phantom, the effective doses from the direct digital panoramic units (37.8 µSv, 27.6 µSv) were higher than those from the indirect units (8.9 µSv, 15.9 µSv). The same panoramic unit showed the difference in effective doses according to the gender of the phantom, numbers and locations of TLDs, and kVp. Conclusion To reasonably assess the radiation risk from various dental radiographic units, the effective doses should be obtained with the same numbers and locations of TLDs, and with standard hospital exposure. After that, it is necessary to survey the effective doses from various dental radiographic units according to the gender with the corresponding phantom. PMID:23807930

  6. Direct Molecular Dynamics Simulation of Electrocaloric Effect in BaTiO3

    NASA Astrophysics Data System (ADS)

    Nishimatsu, Takeshi; A. Barr, Jordan; P. Beckman, Scott

    2013-11-01

    The electrocaloric effect (ECE) in BaTiO3 is simulated using two different first-principles based effective Hamiltonian molecular dynamics methods. The calculations are performed for a wide range of temperatures (30--900 K) and external electric fields (0--500 kV/cm). As expected, a large adiabatic temperature change, Delta-T, at the Curie temperature, T_C, is observed. It is found that for single crystals of pure BaTiO3, the temperature range where a large Delta-T is observed is narrow for small external electric fields (<50 kV/cm). Large fields (>100 kV/cm) may be required to broaden the effective temperature range. The effect of crystal anisotropy on the ECE Delta-T is also investigated. It is found that applying an external electric field along the [001] direction has a larger ECE than those along the [110] and [111] directions.

  7. Design of small MEMS microphone array systems for direction finding of outdoors moving vehicles.

    PubMed

    Zhang, Xin; Huang, Jingchang; Song, Enliang; Liu, Huawei; Li, Baoqing; Yuan, Xiaobing

    2014-01-01

    In this paper, a MEMS microphone array system scheme is proposed which implements real-time direction of arrival (DOA) estimation for moving vehicles. Wind noise is the primary source of unwanted noise on microphones outdoors. A multiple signal classification (MUSIC) algorithm is used in this paper for direction finding associated with spatial coherence to discriminate between the wind noise and the acoustic signals of a vehicle. The method is implemented in a SHARC DSP processor and the real-time estimated DOA is uploaded through Bluetooth or a UART module. Experimental results in different places show the validity of the system and the deviation is no bigger than 6° in the presence of wind noise. PMID:24603636

  8. Design of Small MEMS Microphone Array Systems for Direction Finding of Outdoors Moving Vehicles

    PubMed Central

    Zhang, Xin; Huang, Jingchang; Song, Enliang; Liu, Huawei; Li, Baoqing; Yuan, Xiaobing

    2014-01-01

    In this paper, a MEMS microphone array system scheme is proposed which implements real-time direction of arrival (DOA) estimation for moving vehicles. Wind noise is the primary source of unwanted noise on microphones outdoors. A multiple signal classification (MUSIC) algorithm is used in this paper for direction finding associated with spatial coherence to discriminate between the wind noise and the acoustic signals of a vehicle. The method is implemented in a SHARC DSP processor and the real-time estimated DOA is uploaded through Bluetooth or a UART module. Experimental results in different places show the validity of the system and the deviation is no bigger than 6° in the presence of wind noise. PMID:24603636

  9. Direct effects of diazepam on emotional processing in healthy volunteers

    Microsoft Academic Search

    S. E. Murphy; C. Downham; P. J. Cowen; C. J. Harmer

    2008-01-01

    Rationale  Pharmacological agents used in the treatment of anxiety have been reported to decrease threat relevant processing in patients\\u000a and healthy controls, suggesting a potentially relevant mechanism of action. However, the effects of the anxiolytic diazepam\\u000a have typically been examined at sedative doses, which do not allow the direct actions on emotional processing to be fully\\u000a separated from global effects of

  10. On the treatment of exchange effects in direct reactions

    NASA Astrophysics Data System (ADS)

    Bencze, Gy.; Chandler, C.

    1985-05-01

    Exchange effects in direct reactions are investigated in the framework of the general algebraic theory of identical particle scattering. It is shown that effects due to the permutation symmetry of the system can be separated from the treatment of reaction dynamics. Dynamical aspects of the problem are investigated within the framework of the channel coupling class of N-body theories. Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, USA.

  11. Direct Evidence of Washing out of Nuclear Shell Effects

    E-print Network

    A. Chaudhuri; T. K. Ghosh; K. Banerjee; S. Bhattacharya; Jhilam Sadhukhan; C. Bhattacharya; S. Kundu; J. K. Meena; G. Mukherjee; R. Pandey; T. K. Rana; P. Roy; T. Roy; V. Srivastava; P. Bhattacharya

    2015-04-17

    Constraining excitation energy at which nuclear shell effect washes out has important implications on the production of super heavy elements and many other fields of nuclear physics research. We report the fission fragment mass distribution in alpha induced reaction on an actinide target for wide excitation range in close energy interval and show direct evidence that nuclear shell effect washes out at excitation energy ~40 MeV. Calculation shows that second peak of the ?fission barrier also vanishes around similar excitation energy.

  12. Computer Tools for Structure Elucidation in Effect-Directed Analysis

    Microsoft Academic Search

    Emma Schymanski; Tobias Schulze; Jos Hermans; Werner Brack

    \\u000a The identification of unknown compounds isolated during Effect-Directed Analysis (EDA) is often a hurdle on the way to the\\u000a successful outcome of these studies. Ever-improving separation, analytical, and biological techniques allow the isolation\\u000a of more compounds and effects; however, not all of the compounds contributing to sample toxicity are easily identified. The\\u000a advancement of database search strategies and publishing of

  13. A small molecule directly inhibits the p53 transactivation domain from binding to replication protein A

    PubMed Central

    Glanzer, Jason G.; Carnes, Katie A.; Soto, Patricia; Liu, Shengqin; Parkhurst, Lawrence J.; Oakley, Gregory G.

    2013-01-01

    Replication protein A (RPA), essential for DNA replication, repair and DNA damage signalling, possesses six ssDNA-binding domains (DBDs), including DBD-F on the N-terminus of the largest subunit, RPA70. This domain functions as a binding site for p53 and other DNA damage and repair proteins that contain amphipathic alpha helical domains. Here, we demonstrate direct binding of both ssDNA and the transactivation domain 2 of p53 (p53TAD2) to DBD-F, as well as DBD-F-directed dsDNA strand separation by RPA, all of which are inhibited by fumaropimaric acid (FPA). FPA binds directly to RPA, resulting in a conformational shift as determined through quenching of intrinsic tryptophan fluorescence in full length RPA. Structural analogues of FPA provide insight on chemical properties that are required for inhibition. Finally, we confirm the inability of RPA possessing R41E and R43E mutations to bind to p53, destabilize dsDNA and quench tryptophan fluorescence by FPA, suggesting that protein binding, DNA modulation and inhibitor binding all occur within the same site on DBD-F. The disruption of p53–RPA interactions by FPA may disturb the regulatory functions of p53 and RPA, thereby inhibiting cellular pathways that control the cell cycle and maintain the integrity of the human genome. PMID:23267009

  14. Development of CNG direct injection (CNGDI) clean fuel system for extra power in small engine

    NASA Astrophysics Data System (ADS)

    Ali, Yusoff; Shamsudeen, Azhari; Abdullah, Shahrir; Mahmood, Wan Mohd Faizal Wan

    2012-06-01

    A new design of fuel system for CNG engine with direct injection (CNGDI) was developed for a demonstration project. The development of the fuel system was done on the engine with cylinder head modifications, for fuel injector and spark plug openings included in the new cylinder head. The piston was also redesigned for higher compression ratio. The fuel rails and the regulators are also designed for the direct injection system operating at higher pressure about 2.0 MPa. The control of the injection timing for the direct injectors are also controlled by the Electronic Control Unit specially designed for DI by another group project. The injectors are selected after testing with the various injection pressures and spray angles. For the best performance of the high-pressure system, selection is made from the tests on single cylinder research engine (SCRE). The components in the fuel system have to be of higher quality and complied with codes and standards to secure the safety of engine for high-pressure operation. The results of the CNGDI have shown that better power output is produced and better emissions were achieved compared to the aspirated CNG engine.

  15. Direct Antidiabetic Effect of Leptin through Triglyceride Depletion of Tissues

    Microsoft Academic Search

    Michio Shimabukuro; Kazunori Koyama; Guoxun Chen; May-Yun Wang; Falguni Trieu; Young Lee; Christopher B. Newgard; Roger H. Unger

    1997-01-01

    Leptin is currently believed to control body composition largely, if not entirely, via hypothalamic receptors that regulate food intake and thermogenesis. Here we demonstrate direct extraneural effects of leptin to deplete fat content of both adipocytes and nonadipocytes to levels far below those of pairfed controls. In cultured pancreatic islets, leptin lowered triglyceride (TG) content by preventing TG formation from

  16. Effects of Directed Thinking on Exercise and Cardiovascular Fitness

    E-print Network

    Cooper, Brenton G.

    Effects of Directed Thinking on Exercise and Cardiovascular Fitness Laura L. Ten Eyck1 Children exercise significantly increased time spent on exercising and cardiovas- cular fitness. The results with solutions to improve our overall fitness and health. Television com- mercials hawk everything from special

  17. Direct and Indirect Effects of Online Learning on Distance Education

    ERIC Educational Resources Information Center

    Shin, Namin; Chan, Jason K. Y.

    2004-01-01

    This paper presents an exploratory study that investigates the effects of online learning on distance education students in an open university context. Two hypotheses are posited: (1) a direct relationship exists between students involvement in online learning and distance learning outcomes, and (2) an indirect relationship exists between these…

  18. Direct and Extended Vocabulary Instruction in Kindergarten: Investigating Transfer Effects

    ERIC Educational Resources Information Center

    Coyne, Michael D.; McCoach, D. Betsy; Loftus, Susan; Zipoli, Richard, Jr.; Ruby, Maureen; Crevecoeur, Yvel C.; Kapp, Sharon

    2010-01-01

    The purpose of this study was to investigate the efficacy of an 18-week program of direct and extended vocabulary instruction with kindergarten students on both proximal measures of target word knowledge and transfer measures of generalized language and literacy. A second purpose was to examine whether treatment effects would be moderated by…

  19. Direct and Extended Vocabulary Instruction in Kindergarten: Investigating Transfer Effects

    Microsoft Academic Search

    Michael D. Coyne; D. Betsy McCoach; Susan Loftus; Richard Zipoli Jr; Maureen Ruby; Yvel C. Crevecoeur; Sharon Kapp

    2010-01-01

    The purpose of this study was to investigate the efficacy of an 18-week program of direct and extended vocabulary instruction with kindergarten students on both proximal measures of target word knowledge and transfer measures of generalized language and literacy. A second purpose was to examine whether treatment effects would be moderated by initial receptive vocabulary knowledge measured at pretest. In

  20. Effective hydrogen generator testing for on-site small engine

    Microsoft Academic Search

    Praitoon Chaiwongsa; Nithiroth Pornsuwancharoen; Preecha P. Yupapin

    2009-01-01

    We propose a new concept of hydrogen generator testing for on-site small engine. In general, there is a trade-off between simpler vehicle design and infrastructure issues, for instance, liquid fuels such as gasoline and methanol for small engine use. In this article we compare the hydrogen gases combination the gasoline between normal systems (gasoline only) for small engine. The advantage

  1. Small-molecule-directed nanoparticle assembly towards stimuli-responsive nanocomposites

    NASA Astrophysics Data System (ADS)

    Thorkelsson, Kari; Zhao, Yue; Mastroianni, Alexander; Schilling, Thomas; Luther, Joseph; Rancatore, Benjamin; Matsunaga, Kazuyuki; Jinnai, Hiroshi; Wu, Yue; Poulsen, Daniel; Fréchet, Jean; Alivisatos, Paul; Xu, Ting

    2010-03-01

    The precise control of spatial organization in nanoparticle assemblies would enable one to take advantage of the various optical, electrical, and magnetic properties found in inorganic nanoparticles, but such control is difficult, and remains an impediment in the ``bottom-up'' production of functional materials. Most current methods are either highly dependent on the materials used, or not precise enough to use in the fabrication of functional materials. We show how this challenge has been overcome using a diblock copolymer-based supramolecule. 3-pentadecylphenol was hydrogen bonded to the poly(4-vinylpyridine) block of a polystyrene-block-poly(4-vinylpyridine) diblock copolymer. The alkyl moiety of the small molecules interacts favorably with the alkyl ligands used on a number of nanoparticles, and also forces the poly(4-vinylpyridine) block into a comb conformation. This restricts the location of the nanoparticles and forces them into a well-organized array. This strategy has been successful in assembling nanoparticles without special considerations for the actual core material or shape. A variety of small molecules could also be used.

  2. Early season spring small grains direct proportion estimation - Development and evaluation of a Landsat based methodology

    NASA Technical Reports Server (NTRS)

    Phinney, D. E.; Trichel, M. C.

    1983-01-01

    The Inventory Technology Development (ITD) project of the Agriculture and Resources Inventory Surveys Through Aerospace Remote Sensing (AgRISTARS) program has developed an accurate, automated technology for early season estimation of spring small grains areal proportion from Landsat MSS data. The design criteria for an early season procedure included estimates available within the first 30 days of the growing season, low data processing/preprocessing requirements and no need for scene-to-scene registration. The prototype estimator which meets the design goals is based on a constrained linear model in which the observed spectral response of an entire scene is modeled as a linear combination of the major constituent elements in the scene. The procedure was evaluated over 100 sample segments collected for crop years 1976 through 1979 in the U.S. Northern Great Plains. Analysis of the test results indicated accuracy that compare favorably with both the automated at-harvest technologies tested during the FY81-82 AgRISTARS Spring Small Grains Pilot experiments and earlier analyst-intensive at-harvest technologies.

  3. Effects of compositional defects on small polaron hopping in micas.

    PubMed

    Rosso, Kevin M; Ilton, Eugene S

    2005-06-22

    Hartree-Fock calculations and electron transfer (ET) theory were used to model the effects of compositional defects on ET in the brucite-like octahedral sheet of mica. ET was modeled as an Fe(IIIII) valence interchange reaction across shared octahedral edges of the M2-M2 iron sublattice. The model entails the hopping of localized electrons and small polaron behavior. Hartree-Fock calculations indicate that substitution of F for structural OH bridges increases the reorganization energy lambda, decreases the electronic coupling matrix element V(AB), and thereby substantially decreases the hopping rate. The lambda increase arises from modification of the metal-ligand bond force constants, and the V(AB) decrease arises from reduction of superexchange interaction through anion bridges. Deprotonation of an OH bridge, consistent with a possible mechanism of maintaining charge neutrality during net oxidation, yields a net increase in the ET rate. Although substitution of Al or Mg for Fe in M1 sites distorts the structure of adjacent Fe-occupied M2 sites, the distortion has little net impact on ET rates through these M2 sites. Hence the main effect of Al or Mg substitution for Fe, should it occur in the M2 sublattice, is to block ET pathways. Collectively, these findings pave the way for larger-scale oxidation/reduction models to be constructed for realistic, compositionally diverse micas. PMID:16035795

  4. Effects of Compositional Defects on Small Polaron Hopping in Micas

    SciTech Connect

    Rosso, Kevin M.; Ilton, Eugene S.

    2005-06-01

    Hartree-Fock calculations and electron transfer (ET) theory were used to model the effects of compositional defects on ET in the brucite-like octahedral sheet of mica. ET was modeled as a FeII/III valence interchange reaction across shared octahedral edges of the M2-M2 iron sublattice. The model entails the hopping of localized electrons and small polaron behavior. Hartree-Fock calculations indicate that substitution of F for structural OH bridges increases the reorganization energy l, decreases the electronic coupling matrix element VAB, and thereby substantially decreases the hopping rate. The l increase arises from modification of the metal-ligand bond force constants, and the VAB decrease arises from reduction of superexchange interaction through anion bridges. Deprotonation of an OH bridge, consistent with a possible mechanism of maintaining charge neutrality during net oxidation, yields a net increase in the ET rate. Although substitution of Al or Mg for Fe in M1 sites distorts the structure of adjacent Fe-occupied M2 sites, the distortion has little net impact on ET rates through these M2 sites. Hence the main effect of Al or Mg substitution for Fe, should it occur in the M2 sublattice, is to block ET pathways. Collectively, these findings pave the way for larger-scale oxidation/reduction models to be constructed for realistic, compositionally diverse micas

  5. Luminance effects on visual acuity and small letter contrast sensitivity.

    PubMed

    Rabin, J

    1994-11-01

    The purpose of this study was to evaluate the effects of luminance on visual acuity (VA) and small letter contrast sensitivity (SLCS). Computer-generated letter charts were used to measure VA and SLCS [6/7.5 (20/25) Snellen equivalent] as a function of stimulus luminance. Letter size (VA) and contrast (SLCS) were varied in equal logarithmic steps, making the task and scoring procedure comparable for the two types of measurement. Both VA and SLCS decreased with decreasing luminance, but the effect was far greater in the contrast domain. Reducing luminance from 116 cd/m2 to 0.23 cd/m2 produced a 3 x reduction in VA, but a 17 x reduction in SLCS. The greater sensitivity of SLCS to luminance endured even after correction for greater measurement variability. SLCS is a sensitive approach for detecting resolution loss undisclosed by standard measures of VA. It may be useful for monitoring visual loss from light attenuation in early cataracts, and for detecting subtle resolution loss from neural or pathologic factors in ocular and neuro-ophthalmologic disease. PMID:7885672

  6. Site-directed Mutations Within the Core ``aaa-crystallin'' Domain of the Small Heat-shock Protein, Human aaaB-

    E-print Network

    Clark, John

    Site-directed Mutations Within the Core ``aaa-crystallin'' Domain of the Small Heat-shock Protein-terminal to the core ``a-crystallin'' domain of the small heat-shock protein (sHsp) and molecu- lar chaperone, human aB-crystallin; small heat-shock proteins; core a-crystallin domain; molecular chaperone; protein structure

  7. Effects of desert wildfires on desert tortoise (Gopherus agassizii) and other small vertebrates

    USGS Publications Warehouse

    Esque, T.C.; Schwalbe, C.R.; DeFalco, L.A.; Duncan, R.B.; Hughes, T.J.

    2003-01-01

    We report the results of standardized surveys to determine the effects of wildfires on desert tortoises (Gopherus agassizii) and their habitats in the northeastern Mojave Desert and northeastern Sonoran Desert. Portions of 6 burned areas (118 to 1,750 ha) were examined for signs of mortality of vertebrates. Direct effects of fire in desert habitats included animal mortality and loss of vegetation cover. A range of 0 to 7 tortoises was encountered during surveys, and live tortoises were found on all transects. In addition to desert tortoises, only small (<1 kg) mammals and reptiles (11 taxa) were found dead on the study areas. We hypothesize that indirect effects of fire on desert habitats might result in changes in the composition of diets and loss of vegetation cover, resulting in an increase in predation and loss of protection from temperature extremes. These changes in habitat also might cause changes in vertebrate communities in burned areas.

  8. Measurement of plasma momentum exerted on target by a small helicon plasma thruster and comparison with direct thrust measurement

    NASA Astrophysics Data System (ADS)

    Takahashi, Kazunori; Komuro, Atsushi; Ando, Akira

    2015-02-01

    Momentum, i.e., force, exerted from a small helicon plasma thruster to a target plate is measured simultaneously with a direct thrust measurement using a thrust balance. The calibration coefficient relating a target displacement to a steady-state force is obtained by supplying a dc to a calibration coil mounted on the target, where a force acting to a small permanent magnet located near the coil is directly measured by using a load cell. As the force exerted by the plasma flow to the target plate is in good agreement with the directly measured thrust, the validity of the target technique is demonstrated under the present operating conditions, where the thruster is operated in steady-state. Furthermore, a calibration coefficient relating a swing amplitude of the target to an impulse bit is also obtained by pulsing the calibration coil current. The force exerted by the pulsed plasma, which is estimated from the measured impulse bit and the pulse width, is also in good agreement with that obtained for the steady-state operation; hence, the thrust assessment of the helicon plasma thruster by the target is validated for both the steady-state and pulsed operations.

  9. Direct current electrical potential measurement of the growth of small cracks

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Slavik, Donald C.; Piascik, Robert S.; Van Stone, Robert H.

    1992-01-01

    The analytical and experimental aspects of the direct-current electrical potential difference (dcEPD) method for continuous monitoring of the growth kinetics of short (50 to 500 microns) fatigue cracks are reviewed, and successful applications of the deEPD method to study fatigue crack propagation in a variety of metallic alloys exposed to various environments are described. Particular attention is given to the principle of the dcEPD method, the analytical electrical potential calibration relationships, and the experimental procedures and equipment.

  10. Parent socialization effects in different cultures: significance of directive parenting.

    PubMed

    Sorkhabi, Nadia

    2012-06-01

    In this article, the controversy of divergent findings in research on parental socialization effects in different cultures is addressed. Three explanations intended to address divergent findings of socialization effects in different cultures, as advanced by researchers who emphasize cultural differences, are discussed. These include cultural differences in socialization values and goals of parents, parental emotional and cognitive characteristics associated with parenting styles, and adolescents' interpretations or evaluations of their parents' parenting styles. The empirical evidence for and against each of these arguments is examined and an alternative paradigm for understanding and empirical study of developmental outcomes associated with parenting styles in different cultures is suggested. Baumrind's directive parenting style is presented as an alternative to the authoritarian parenting style in understanding the positive developmental effects associated with "strict" parenting in cultures said to have a collectivist orientation. Directions for research on the three explanations are mentioned. PMID:22897089

  11. Small-molecule-directed nanoparticle assembly towards stimuli-responsive nanocomposites.

    PubMed

    Zhao, Yue; Thorkelsson, Kari; Mastroianni, Alexander J; Schilling, Thomas; Luther, Joseph M; Rancatore, Benjamin J; Matsunaga, Kazuyuki; Jinnai, Hiroshi; Wu, Yue; Poulsen, Daniel; Fréchet, Jean M J; Alivisatos, A Paul; Xu, Ting

    2009-12-01

    Precise control of the spatial organization of nanoscopic building blocks, such as nanoparticles, over multiple length scales is a bottleneck in the 'bottom-up' generation of technologically important materials. Only a few approaches have been shown to achieve nanoparticle assemblies without surface modification. We demonstrate a simple yet versatile approach to produce stimuli-responsive hierarchical assemblies of readily available nanoparticles by combining small molecules and block copolymers. Organization of nanoparticles into one-, two- and three-dimensional arrays with controlled inter-particle separation and ordering is achieved without chemical modification of either the nanoparticles or block copolymers. Nanocomposites responsive to heat and light are demonstrated, where the spatial distribution of the nanoparticles can be varied by exposure to heat or light or changing the local environment. The approach described is applicable to a wide range of nanoparticles and compatible with existing fabrication processes, thereby enabling a non-disruptive approach for the generation of functional devices. PMID:19838181

  12. Direct fabrication of ordered mesoporous carbons with super-micropore/small mesopore using mixed triblock copolymers.

    PubMed

    Li, Peng; Song, Yan; Tang, Zhihong; Yang, Guangzhi; Yang, Junhe

    2014-01-01

    Ordered mesoporous carbons (OMCs) have been prepared by the strategy of evaporation-induced organic-organic self-assembly method by employing a mixture of amphiphilic triblock copolymers poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) and reverse PPO-PEO-PPO as templates, with soluble in ethanol, low-molecular-weight phenolic resin as precursor, followed by carbonization. It has been found that the as prepared OMCs with porosity that combines super-micropore and small mesopore size distributed from 0.8 to 4 nm, which bridges the pore size from 2 to 3 nm and also for the diversification of the soft-templating synthesis of OMCs. Furthermore, the results showed that the OMCs obtained have mesophase transition from cylindrical p6 mm to centered rectangular c2 mm structure by simply tuning the ratio of PPO-PEO-PPO/PEO-PPO-PEO. PMID:24183444

  13. Modified Habitats Influence Kelp Epibiota via Direct and Indirect Effects

    PubMed Central

    Marzinelli, Ezequiel M.; Underwood, Antony J.; Coleman, Ross A.

    2011-01-01

    Addition of man-made structures alters abiotic and biotic characteristics of natural habitats, which can influence abundances of biota directly and/or indirectly, by altering the ecology of competitors or predators. Marine epibiota in modified habitats were used to test hypotheses to distinguish between direct and indirect processes. In Sydney Harbour, kelps on pier-pilings supported greater covers of bryozoans, particularly of the non-indigenous species Membranipora membranacea, than found on natural reefs. Pilings influenced these patterns and processes directly due to the provision of shade and indirectly by altering abundances of sea-urchins which, in turn, affected covers of bryozoans. Indirect effects were more important than direct effects. This indicates that artificial structures affect organisms living on secondary substrata in complex ways, altering the biodiversity and indirectly affecting abundances of epibiota. Understanding how these components of habitats affect ecological processes is necessary to allow sensible prediction of the effects of modifying habitats on the ecology of organisms. PMID:21755011

  14. Modified habitats influence kelp epibiota via direct and indirect effects.

    PubMed

    Marzinelli, Ezequiel M; Underwood, Antony J; Coleman, Ross A

    2011-01-01

    Addition of man-made structures alters abiotic and biotic characteristics of natural habitats, which can influence abundances of biota directly and/or indirectly, by altering the ecology of competitors or predators. Marine epibiota in modified habitats were used to test hypotheses to distinguish between direct and indirect processes. In Sydney Harbour, kelps on pier-pilings supported greater covers of bryozoans, particularly of the non-indigenous species Membranipora membranacea, than found on natural reefs. Pilings influenced these patterns and processes directly due to the provision of shade and indirectly by altering abundances of sea-urchins which, in turn, affected covers of bryozoans. Indirect effects were more important than direct effects. This indicates that artificial structures affect organisms living on secondary substrata in complex ways, altering the biodiversity and indirectly affecting abundances of epibiota. Understanding how these components of habitats affect ecological processes is necessary to allow sensible prediction of the effects of modifying habitats on the ecology of organisms. PMID:21755011

  15. Direct and indirect effects of southern flounder predation on a spot population: Experimental and model analyses

    SciTech Connect

    Crowder, L.B.; Wright, R.A.; Martin, T.H.; Rice, J.A. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Zoology; Rose, K.A. [Oak Ridge National Lab., TN (United States)

    1992-12-31

    We have previously shown that southern flounder (Paralichthys lethostigma Jordan and Gilbert) influence the survival and size-distribution of spot (Leiostomus xanthurus Lafayette) and other small estuarine fishes in experimental ponds. In this paper, we seek to determine whether these of effects can be accounted for by direct size-dependent predation or if there is also evidence for indirect behavioral effects on spot foraging which might alter their survival or population size structure. In our experiment, spot were allowed to grow in the presence and absence of southern flounder in an experimental estuarine pond for 101 days. Each treatment was replicated three times. We also apply a recently published simulation model of the flounder-spot interaction to this experiment to independently test the model and to estimate the direct effects of flounder predation on spot survival and size structure.

  16. Direct and indirect effects of southern flounder predation on a spot population: Experimental and model analyses

    SciTech Connect

    Crowder, L.B.; Wright, R.A.; Martin, T.H.; Rice, J.A. (North Carolina State Univ., Raleigh, NC (United States). Dept. of Zoology); Rose, K.A. (Oak Ridge National Lab., TN (United States))

    1992-01-01

    We have previously shown that southern flounder (Paralichthys lethostigma Jordan and Gilbert) influence the survival and size-distribution of spot (Leiostomus xanthurus Lafayette) and other small estuarine fishes in experimental ponds. In this paper, we seek to determine whether these of effects can be accounted for by direct size-dependent predation or if there is also evidence for indirect behavioral effects on spot foraging which might alter their survival or population size structure. In our experiment, spot were allowed to grow in the presence and absence of southern flounder in an experimental estuarine pond for 101 days. Each treatment was replicated three times. We also apply a recently published simulation model of the flounder-spot interaction to this experiment to independently test the model and to estimate the direct effects of flounder predation on spot survival and size structure.

  17. Direct and indirect effects of the glyphosate formulation Glifosato Atanor® on freshwater microbial communities.

    PubMed

    Vera, María Solange; Di Fiori, Eugenia; Lagomarsino, Leonardo; Sinistro, Rodrigo; Escaray, Roberto; Iummato, María Mercedes; Juárez, Angela; Ríos de Molina, María del Carmen; Tell, Guillermo; Pizarro, Haydée

    2012-10-01

    Glyphosate-based formulations are among the most widely used herbicides in the world. The effect of the formulation Glifosato Atanor(®) on freshwater microbial communities (phytoplankton, bacterioplankton, periphyton and zooplankton) was assessed through a manipulative experiment using six small outdoor microcosms of small volume. Three of the microcosms were added with 3.5 mg l(-1) of glyphosate whereas the other three were left as controls without the herbicide. The treated microcosms showed a significant increase in total phosphorus, not fully explained by the glyphosate present in the Glifosato Atanor(®). Therefore, part of the phosphorus should have come from the surfactants of the formulation. The results showed significant direct and indirect effects of Glifosato Atanor(®) on the microbial communities. A single application of the herbicide caused a fast increase both in the abundance of bacterioplankton and planktonic picocyanobacteria and in chlorophyll a concentration in the water column. Although metabolic alterations related to oxidative stress were induced in the periphyton community, the herbicide favored its development, with a large contribution of filamentous algae typical of nutrient-rich systems, with shallow and calm waters. An indirect effect of the herbicide on the zooplankton was observed due to the increase in the abundance of the rotifer Lecane spp. as a consequence of the improved food availability given by picocyanobacteria and bacteria. The formulation affected directly a fraction of copepods as a target. It was concluded that the Glifosato Atanor(®) accelerates the deterioration of the water quality, especially when considering small-volume water systems. PMID:22539117

  18. Networking genetic regulation and neural computation: directed network topology and its effect on the dynamics.

    PubMed

    Grönlund, Andreas

    2004-12-01

    Two different types of directed networks are investigated, transcriptional regulation networks and neural networks. The directed network structure is studied and is also shown to reflect the different processes taking place on the networks. The distribution of influence, identified as the the number of downstream vertices, are used as a tool for investigating random vertex removal. In the transcriptional regulation networks we observe that only a small number of vertices have a large influence. The small influences of most vertices limit the effect of a random removal to, in most cases, only a small fraction of vertices in the network. The neural network has a rather different topology with respect to the influence, which are large for most vertices. To further investigate the effect of vertex removal we simulate the biological processes taking place on the networks. Opposed to the presumed large effect of random vertex removal in the neural network, the high density of edges in conjunction with the dynamics used makes the change in the state of the system to be highly localized around the removed vertex. PMID:15697403

  19. Networking genetic regulation and neural computation: Directed network topology and its effect on the dynamics

    NASA Astrophysics Data System (ADS)

    Grönlund, Andreas

    2004-12-01

    Two different types of directed networks are investigated, transcriptional regulation networks and neural networks. The directed network structure is studied and is also shown to reflect the different processes taking place on the networks. The distribution of influence, identified as the the number of downstream vertices, are used as a tool for investigating random vertex removal. In the transcriptional regulation networks we observe that only a small number of vertices have a large influence. The small influences of most vertices limit the effect of a random removal to, in most cases, only a small fraction of vertices in the network. The neural network has a rather different topology with respect to the influence, which are large for most vertices. To further investigate the effect of vertex removal we simulate the biological processes taking place on the networks. Opposed to the presumed large effect of random vertex removal in the neural network, the high density of edges in conjunction with the dynamics used makes the change in the state of the system to be highly localized around the removed vertex.

  20. Direct Radiative Effects of Absorbing Aerosols on Indian Summer Monsoon

    NASA Astrophysics Data System (ADS)

    Shin, H.; Wang, C.

    2011-12-01

    Recent studies presented that direct radiative forcing of anthropogenic aerosols, particularly absorbing aerosols, can affect pre-monsoon seasonal climate and hydrology. Such effect can be implemented through perturbation to the large-scale atmospheric stability by persistent aerosol forcing. Due to the population growth and industrialization, anthropogenic aerosols have markedly increased over South Asia. Using a coupled climate model, we have further analyzed the direct radiative effects of aerosols on South Asian monsoon system, especially the aerosol effects on the onset, distribution, and strength of Indian summer monsoon rainfall. With the model, several sets of 30 to 100 year-long simulations were carried out. Paired simulations including absorbing aerosols' direct radiative effects respectively with atmospheric heating, surface cooling and the total heat forcing are designed to isolate climate responses to absorbing aerosols. As relatively coarse spatial model resolution and simulation bias being considered, a new estimation method for Indian summer monsoon onset was proposed and compared with observational data. When included the total heat forcing, our model simulated the monsoon with a broader period of the onset period making the onset less predictable. The monsoon rainfall with low intensity (8 mm/day) was increased by about 0.5 mm/day and the rainfall with high intensity (10 mm/day) appeared less frequently. Forcing due to aerosols at the right place and time can alter the behavior of the monsoon system.

  1. Effective hydrogen generator testing for on-site small engine

    NASA Astrophysics Data System (ADS)

    Chaiwongsa, Praitoon; Pornsuwancharoen, Nithiroth; Yupapin, Preecha P.

    2009-07-01

    We propose a new concept of hydrogen generator testing for on-site small engine. In general, there is a trade-off between simpler vehicle design and infrastructure issues, for instance, liquid fuels such as gasoline and methanol for small engine use. In this article we compare the hydrogen gases combination the gasoline between normal systems (gasoline only) for small engine. The advantage of the hydrogen combines gasoline for small engine saving the gasoline 25%. Furthermore, the new concept of hydrogen combination for diesel engine, bio-diesel engine, liquid petroleum gas (LPG), natural gas vehicle (NGV), which is discussed in details.

  2. EGFR-directed monoclonal antibodies in non-small cell lung cancer: how to predict efficacy?

    PubMed Central

    2012-01-01

    Cetuximab improved survival when added to first-line platinum-based chemotherapy in patients with advanced non-small cell lung cancer. In order to determine those patients who will derive the greatest benefit from the addition of cetuximab, the associations of clinical and tumor features with clinical outcome were determined. High EGFR expression of tumor cells based on an immunohistochemistry score was shown to predict benefit of cetuximab. Among patients with high EGFR expression, the hazard ratio for death was 0.73 in favor of chemotherapy plus cetuximab compared to chemotherapy alone. Among patients with low EGFR expression, no difference in survival was observed between patients treated with chemotherapy plus cetuximab compared to those treated with chemotherapy alone. The treatment interaction test was significant. KRAS mutation status and EGFR copy numbers were without predictive value. Patients with EGFR-activating mutations in their tumors had longer survival independent of the use of cetuximab. In conclusion, EGFR expression levels lend themselves as predictive biomarkers for the selection of those patients who will benefit from the addition of cetuximab to first-line chemotherapy with platinum-based doublets.

  3. Effects of rejecting diffusion directions on tensor-derived parameters.

    PubMed

    Chen, Yiran; Tymofiyeva, Olga; Hess, Christopher P; Xu, Duan

    2015-04-01

    Diffusion Tensor Imaging (DTI) is adversely affected by subject motion. It is necessary to discard the corrupted images before diffusion parameter estimation. However, the consequences of rejecting those images are not well understood. In this study, we investigated the effects of excluding one or more volumes of diffusion weighted images by analyzing the changes in fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD) and the primary eigenvector (V1). Based on the full set of diffusion images acquired by the Jones30 diffusion scheme, we generated incomplete sets of at least six in three different ways: random, uniform and clustered rejections. The results showed that MD was not significantly affected by rejecting diffusion directions. In the cases of random rejections, FA, AD, RD and V1 were overestimated more greatly with increasing number of rejections and the overestimations were worse in low FA regions than high FA regions. For uniform rejections, at which the remaining diffusion directions are evenly distributed on a sphere, little change was observed in FA and in V1. Clustered rejections, on the other hand, displayed the most significant overestimation of the parameters, and the resulting accuracy depended on the relative orientation of the underlying fibers with respect to the excluded directions. In practice, if diffusion direction data is excluded, it is important to note the number and location of directions rejected, in order to make a more precise analysis of the data. PMID:25585018

  4. Synthesis of stable ultra-small Cu nanoparticles for direct writing flexible electronics

    NASA Astrophysics Data System (ADS)

    Li, Wei; Chen, Minfang

    2014-01-01

    In this study, pure Cu nanoparticles (NPs) have been successfully synthesized and the Cu nano-ink was prepared for direct writing on photo paper using a roller pen. The tri-sodium citrate was used as initial reducing-cum-surfactant agent followed by hydrazine as a second massive reducing agent and cetyltrimethylammonium bromide (CTAB) as extra surfactant agent. From the XRD, TEM, and HR-TEM analyses, the synthesized particles are confirmed to be Cu in spherical shape with sizes range of 2.5 ± 1.0 nm. By analyzing the FT-IR spectroscopy and TGA curves, it was found that the obtained particles capped with tri-sodium citrate and CTAB layers are stable to oxidation up to the temperature 228 °C. The reduced size and enhanced air-stability of the Cu NPs result in an improved particle density upon sintering, which is mainly responsible for the increased conductivity of the Cu patterns. The resistivity of Cu patterns sintered in Ar at 160 °C for 2 h is 7.2 ± 0.6 ?? cm, which is 4.40 times the bulk Cu resistivity. The drawn Cu lines exhibited excellent integrity and good conductivity, which were experimentally tested. Moreover, a Cu electrode and a sample RFID antenna were successfully made.

  5. Direct observation of small cluster mobility and ripening. [during annealing of metal films on amorphous substrates

    NASA Technical Reports Server (NTRS)

    Heinemann, K.; Poppa, H.

    1975-01-01

    Direct evidence is reported for the simultaneous occurrence of Ostwald ripening and short-distance cluster mobility during annealing of discontinuous metal films on clean amorphous substrates. The annealing characteristics of very thin particulate deposits of silver on amorphized clean surfaces of single crystalline thin graphite substrates were studied by in-situ transmission electron microscopy (TEM) under controlled environmental conditions (residual gas pressure of 10 to the minus 9th power torr) in the temperature range from 25 to 450 C. Sputter cleaning of the substrate surface, metal deposition, and annealing were monitored by TEM observation. Pseudostereographic presentation of micrographs in different annealing stages, the observation of the annealing behavior at cast shadow edges, and measurements with an electronic image analyzing system were employed to aid the visual perception and the analysis of changes in deposit structure recorded during annealing. Slow Ostwald ripening was found to occur in the entire temperature range, but the overriding surface transport mechanism was short-distance cluster mobility.

  6. Brisk and Effective Fluency Instruction for Small Groups

    ERIC Educational Resources Information Center

    Wilson, Judith K.

    2012-01-01

    Fluency is known as the bridge between phonics and comprehension. Teachers of reading provide high-quality instruction in phonics and decoding strategies, usually in a small-group format, but may be unsure how to insert fluency instruction into the small-group lesson. This article presents key concepts in fluency instruction and a description of…

  7. Effects of fire on small commercial gas cylinders

    Microsoft Academic Search

    N. Davison; M. R. Edwards

    2008-01-01

    Current standards on the safety of small portable gas cylinders only define the pressures at temperatures of up to 50°C and therefore have limited applicability in situations where cylinders are close to fires. Cylinders containing a pressurised liquid butane–propane mixture were heated in a small barbecue. The cylinders underwent a boiling liquid expanding gas explosion (BLEVE) at a liquid temperature

  8. Effect of small additions of carbon nanotubes on the electrical conductivity of polyurethane elastomer

    NASA Astrophysics Data System (ADS)

    Novikov, G. F.; Rabenok, E. V.; Estrin, Ya. I.; Ol'hov, Yu. A.; Badamshina, E. R.

    2014-10-01

    The effect of small (0.002-0.018 wt %) additions of single-walled carbon nanotubes on the dielectric properties and electrical conductivity of crosslinked polyurethane elastomer is studied in the temperature range of 133-453 K and the 10-3 to 105 Hz range of electric field frequencies. It is shown that the dependence of direct current conductivity ? dc on temperature deviates significantly from the Arrhenius dependence and is described by the Vogel-Fulcher-Tamman equation ? dc = ? dc0exp{- DT 0/( T - T 0)}, where T 0 is the Vogel temperature and D is the strength parameter. A correlation is found between the nonmonotonic dependences of the glass transition temperature ( T g), D parameter, and ? dc and the concentration of nanotubes with earlier results for their effects on the physicomechanical characteristics (strength and Young's modulus) of these systems.

  9. Effect of Speed (Centrifugal Load) on Gear Crack Propagation Direction

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.

    2001-01-01

    The effect of rotational speed (centrifugal force) on gear crack propagation direction was explored. Gears were analyzed using finite element analysis and linear elastic fracture mechanics. The analysis was validated with crack propagation experiments performed in a spur gear fatigue rig. The effects of speed, rim thickness, and initial crack location on gear crack propagation direction were investigated. Crack paths from the finite element method correlated well with those deduced from gear experiments. For the test gear with a backup ratio (rim thickness divided by tooth height) of nib = 0.5, cracks initiating in the tooth fillet propagated to rim fractures when run at a speed of 10,000 rpm and became tooth fractures for speeds slower than 10,000 rpm for both the experiments and anal sis. From additional analysis, speed had little effect on crack propagation direction except when initial crack locations were near the tooth/rim fracture transition point for a given backup ratio. When at that point, higher speeds tended to promote rim fracture while lower speeds (or neglecting centrifugal force) produced tooth fractures.

  10. Direct mapping of nuclear shell effects in the heaviest elements

    E-print Network

    E. Minaya Ramirez; D. Ackermann; K. Blaum; M. Block; C. Droese; Ch. E. Düllmann; M. Dworschak; M. Eibach; S. Eliseev; E. Haettner; F. Herfurth; F. P. Heßberger; S. Hofmann; J. Ketelaer; G. Marx; M. Mazzocco; D. Nesterenko; Yu. N. Novikov; W. R. Plaß; D. Rodríguez; C. Scheidenberger; L. Schweikhard; P. G. Thirolf; C. Weber

    2014-06-25

    Quantum-mechanical shell effects are expected to strongly enhance nuclear binding on an "island of stability" of superheavy elements. The predicted center at proton number $Z=114,120$, or $126$ and neutron number $N=184$ has been substantiated by the recent synthesis of new elements up to $Z=118$. However the location of the center and the extension of the island of stability remain vague. High-precision mass spectrometry allows the direct measurement of nuclear binding energies and thus the determination of the strength of shell effects. Here, we present such measurements for nobelium and lawrencium isotopes, which also pin down the deformed shell gap at $N=152$.

  11. TIME-LINEARISED TRANSONIC SMALL DISTURBANCE CODE INCLUDING ENTROPY AND VORTICITY EFFECTS

    Microsoft Academic Search

    Eddie Ly; Jiro Nakamichi

    2002-01-01

    The effect of small perturbations on steady transonic small-disturbance flo wfield is studied. A time-linearised time-domain solution method that includes the shock motion effects via a shock jump correction procedure is presented. This correctly accounts for the small-amplitude shock motions due to small unsteady changes in the aerofoil boundary condition. The method also in- cludes the shock-generated entropy and vorticity

  12. Cost-Effectiveness of Health Risk Reduction After Lifestyle Education in the Small Workplace

    PubMed Central

    Allen, Jorie C.; Lewis, James B.

    2012-01-01

    Introduction Investigations suggest that worksite health promotions in large companies decrease employer health costs and the risk for chronic disease. However, evidence of the success of such programs in small organizations is lacking. The purpose of this study was to determine whether a worksite health promotion program improves health risk and is cost-effective for a small employer. Methods Intervention (n = 29) and comparison (n = 31) participants from a 172-employee organization underwent health screening of risk factors for coronary heart disease at baseline (fall 2006) and at 12 months (fall 2007). The intervention group attended lifestyle education videoconferences and reported physical activity. We used the Framingham Risk Score to calculate risk of coronary heart disease. To calculate cost-effectiveness, we used direct employer costs of the program divided by either the relative reduction in low-density lipoprotein cholesterol or the absolute change in coronary heart disease risk. Results At 12 months, low-density lipoprotein cholesterol, total cholesterol, and number of metabolic syndrome markers were significantly higher in the comparison group than in the intervention group. Total cholesterol was significantly lower at 12 months than at baseline in the intervention group. Waist circumference and number of metabolic syndrome markers increased significantly from baseline in the comparison group. Cost-effectiveness of the intervention was $10.17 per percentage-point reduction of low-density lipoprotein cholesterol and $454.23 per point reduction in coronary heart disease risk. Conclusion This study demonstrated the cost-effectiveness in a small organization of a worksite health promotion that improved low-density lipoproteins and coronary heart disease risk in participating employees. PMID:22575081

  13. Small intestinal submucosa as a small-caliber venous graft: A novel model for hepatocyte transplantation on synthetic biodegradable polymer scaffolds with direct access to the portal venous system

    Microsoft Academic Search

    Stephen S Kim; Satoshi Kaihara; Mark S Benvenuto; Byung-Soo Kim; David J Mooney; Joseph P Vacanti

    1999-01-01

    Background\\/Purpose: Hepatotrophic factors in the portal blood are critically important for the survival of heterotopically transplanted hepatocytes. Currently, no model exists for the implantation of hepatocytes on biodegradable polymer scaffolds with direct access to the portal blood. This study investigates the use of small intestinal submucosa (SIS) as a small-caliber venous conduit that may be used for the implantation of

  14. Direct-to-consumer advertising: its effects on stakeholders.

    PubMed

    Montoya, Isaac D; Lee-Dukes, Gwen; Shah, Dhvani

    2008-01-01

    The escalating growth in the development of pharmaceutical drugs has caused the pharmaceutical industry to market drugs directly to consumers. Direct-to-consumer (DTC) advertising has increased immensely in the past 15 years and continues to grow each year. The advantages of DTC advertising include an increase in consumer knowledge, patient autonomy, and possibly providing physicians and pharmacists with up-to-date information about the recent trends in the marketplace. However, there is also an equally notable list of disadvantages, which include concerns about the quality of information provided, loss in physician productivity due to time spent convincing patients that what they want is not in their best interest, and increases in the reimbursement expenditure of the insurers. Because of these conflicting outcomes, the issue of DTC advertising has become controversial. This report offers an overview of DTC advertising and focuses on its effects on physicians, pharmacists, consumers, insurers, the government, and pharmaceutical manufacturers. PMID:18630788

  15. Dark matter effective field theory scattering in direct detection experiments

    E-print Network

    Schneck, K; Cerdeno, D G; Mandic, V; Rogers, H E; Agnese, R; Anderson, A J; Asai, M; Balakishiyeva, D; Barker, D; Thakur, R Basu; Bauer, D A; Billard, J; Borgland, A; Brandt, D; Brink, P L; Bunker, R; Caldwell, D O; Calkins, R; Chagani, H; Chen, Y; Cooley, J; Cornell, B; Crewdson, C H; Cushman, P; Daal, M; Di Stefano, P C F; Doughty, T; Esteban, L; Fallows, S; Figueroa-Feliciano, E; Godfrey, G L; Golwala, S R; Hall, J; Harris, H R; Hofer, T; Holmgren, D; Hsu, L; Huber, M E; Jardin, D M; Jastram, A; Kamaev, O; Kara, B; Kelsey, M H; Kennedy, A; Leder, A; Loer, B; Asamar, E Lopez; Lukens, P; Mahapatra, R; McCarthy, K A; Mirabolfathi, N; Moffatt, R A; Mendoza, J D Morales; Oser, S M; Page, K; Page, W A; Partridge, R; Pepin, M; Phipps, A; Prasad, K; Pyle, M; Qiu, H; Rau, W; Redl, P; Reisetter, A; Ricci, Y; Roberts, A; Saab, T; Sadoulet, B; Sander, J; Schnee, R W; Scorza, S; Serfass, B; Shank, B; Speller, D; Toback, D; Upadhyayula, S; Villano, A N; Welliver, B; Wilson, J S; Wright, D H; Yang, X; Yellin, S; Yen, J J; Young, B A; Zhang, J

    2015-01-01

    We examine the consequences of the effective field theory (EFT) of dark matter-nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  16. Direction Dependent Effects In Widefield Wideband Full Stokes Radio Imaging

    NASA Astrophysics Data System (ADS)

    Jagannathan, Preshanth; Bhatnagar, Sanjay; Rau, Urvashi; Taylor, Russ

    2015-01-01

    Synthesis imaging in radio astronomy is affected by instrumental and atmospheric effects which introduce direction dependent gains.The antenna power pattern varies both as a function of time and frequency. The broad band time varying nature of the antenna power pattern when not corrected leads to gross errors in full stokes imaging and flux estimation. In this poster we explore the errors that arise in image deconvolution while not accounting for the time and frequency dependence of the antenna power pattern. Simulations were conducted with the wideband full stokes power pattern of the Very Large Array(VLA) antennas to demonstrate the level of errors arising from direction-dependent gains. Our estimate is that these errors will be significant in wide-band full-pol mosaic imaging as well and algorithms to correct these errors will be crucial for many up-coming large area surveys (e.g. VLASS)

  17. Higher dimensional effective operators for direct dark matter detection

    NASA Astrophysics Data System (ADS)

    Krauss, Martin B.; Morisi, Stefano; Porod, Werner; Winter, Walter

    2014-02-01

    We discuss higher dimensional effective operators describing interactions between fermionic dark matter and Standard Model particles. They are typically suppressed compared to the leading order effective operators, which can explain why no conclusive direct dark matter detection has been made so far. The ultraviolet completions of the effective operators, which we systematically study, require new particles. These particles can potentially have masses at the TeV scale and can therefore be phenomenologically interesting for LHC physics. We demonstrate that the lowest order options require Higgsportal interactions generated by dimension six operators. We list all possible tree-level completions with extra fermions and scalars, and we discuss the LHC phenomenology of a specific example with extra heavy fermion doublets.

  18. ELLIS, JOSEPH. The RNA World: A Look at Ribonuclease P RNA, Small Nucleolar RNA, 6S RNA, and the Small Ribosomal Subunit. (Under the Direction of James W.

    E-print Network

    Brown, James W.

    ABSTACT ELLIS, JOSEPH. The RNA World: A Look at Ribonuclease P RNA, Small Nucleolar RNA, 6S RNA, SMALL NUCLEOLAR RNA, 6S RNA, AND THE SMALL RIBOSOMAL SUBUNIT by Joseph Ellis A dissertation and support. I would to thank my mother and father Ron and Pat Ellis for all they have done for me, not only

  19. Effect of radiation protraction in intensity-modulated radiation therapy with direct aperture optimization: a phantom study

    NASA Astrophysics Data System (ADS)

    Kuperman, V. Y.; Ventura, A. M.; Sommerfeldt, M.

    2008-06-01

    The effect of radiation protraction in step-and-shoot IMRT is investigated for treatment plans created with the help of direct aperture optimization. The latter approach can be used during inverse planning for all clinical linear accelerators with conventional MLC. Direct aperture optimization significantly shortens fraction time for IMRT plans as compared to that for plans obtained by using the conventional inverse planning approach. By analyzing several IMRT plans obtained with direct aperture optimization we found that for ?/? ratio of 10 Gy (characteristic of fast growing tumors) the protraction effect is probably clinically insignificant for both conventional and large fraction sizes of 1.9 Gy and 5.7 Gy, respectively. For small ?/? of 1-1.5 Gy and conventional fraction size the effect of protraction is still small; however, this effect can be significant for hypofractionated treatments. Based on the obtained results it is recommended that, when possible, IMRT for slow growing prostate cancers be performed with small number of beams (e.g., 5) and small number of segments (e.g., 5-7 segments per beam) to reduce delivery time and, as a result, the associated effect of radiation protraction.

  20. Direct Pro-Inflammatory Effects of Prorenin on Microglia

    PubMed Central

    Shi, Peng; Grobe, Justin L.; Desland, Fiona A.; Zhou, Guannan; Shen, Xiao Z.; Shan, Zhiying; Liu, Meng; Raizada, Mohan K.; Sumners, Colin

    2014-01-01

    Neuroinflammation has been implicated in hypertension, and microglia have been proposed to play an important role in the progression of this disease. Here, we have studied whether microglia are activated within cardiovascular regulatory area(s) of the brain during hypertension, especially in high blood pressure that is associated with chronic activation of the renin-angiotensin-system. In addition, we determined whether prorenin, an essential component of the renin-angiotensin-system, exerts direct pro-inflammatory effects on these microglia. Our data indicate that two rodent models which display neurogenic hypertension and over activation of the renin-angiotensin-system in the brain (sRA mice and spontaneously hypertensive rats) exhibit microglial activation, and increased levels of pro-inflammatory cytokines, in the paraventricular nucleus of the hypothalamus, an area crucial for regulation of sympathetic outflow. Further, the renin-angiotensin-system component prorenin elicits direct activation of hypothalamic microglia in culture and induction of pro-inflammatory mechanisms in these cells, effects that involve prorenin receptor-induced NF?B activation. In addition, the prorenin-elicited increases in cytokine expression were fully abolished by microglial inhibitor minocycline, and were potentiated by pre-treatment of cells with angiotensin II. Taken together with our previous data which indicate that pro-inflammatory processes in the paraventricular nucleus are involved in the hypertensive action of renin-angiotensin-system, the novel discovery that prorenin exerts direct stimulatory effects on microglial activation and pro-inflammatory cytokine production provides support for the idea that renin-angiotensin-system -induced neurogenic hypertension is not restricted to actions of angiotensin II alone. PMID:25302502

  1. Aerosol direct and indirect radiative effect over Eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Georgoulias, Aristeidis; Alexandri, Georgia; Zanis, Prodromos; Ntogras, Christos; Poeschl, Ulrich; Kourtidis, Kostas

    In this work, we present results from the QUADIEEMS project which is focused on the aerosol-cloud relations and the aerosol direct and indirect radiative effect over the region of Eastern Mediterranean. First, a gridded dataset at a resolution of 0.1x0.1 degrees (~10km) with aerosol and cloud related parameters was compiled, using level-2 satellite observations from MODIS TERRA (3/2000-12/2012) and AQUA (7/2002-12/2012). The aerosol gridded dataset has been validated against sunphotometric measurements from 12 AERONET ground stations, showing that generally MODIS overestimates aerosol optical depth (AOD550). Then, the AOD550 and fine mode ratio (FMR550) data from MODIS were combined with aerosol index (AI) data from the Earth Probe TOMS and OMI satellite sensors, wind field data from the ERA-interim reanalysis and AOD550 data for various aerosol types from the GOCART model and the MACC reanalysis to quantify the relative contribution of different aerosol types (marine, dust, anthropogenic, fine-mode natural) to the total AOD550. The aerosol-cloud relations over the region were investigated with the use of the joint high resolution aerosol-cloud gridded dataset. Specifically, we focused on the seasonal relations between the cloud droplet number concentration (CDNC) and AOD550. The aerosol direct and first indirect radiative effect was then calculated for each aerosol type separately making use of the aerosol relative contribution to the total AOD550, the CDND-AOD550 relations and satellite-based parameterizations. The direct radiative effect was also quantified using simulations from a regional climate model (REGCM4), simulations with a radiative transfer model (SBDART) and the three methods were finally intervalidated.

  2. Herbivory in global climate change research: direct effects of rising temperature on insect herbivores

    Microsoft Academic Search

    Jeffery S. Bale; Gregory J. Masters; Ian D. Hodkinson; Caroline Awmack; T. Martijn Bezemer; Valerie K. Brown; Jennifer Butterfield; Alan Buse; John C. Coulson; John Farrar; John E. G. Good; Richard Harrington; Susane Hartley; T. Hefin Jones; Richard L. Lindroth; Ilias Symrnioudis; Allan D. Watt; John B. Whittaker

    2002-01-01

    This review examines the direct effects of climate change on insect herbivores. Temperature is identified as the dominant abiotic factor directly affecting herbivorous insects. There is little evidence of any direct effects Of CO2 or UVB. Direct impacts of precipitation have been largely neglected in current research on climate change. Temperature directly affects development, survival, range and abundance. Species with

  3. Effect of dietary fat on the small intestinal mucosa.

    PubMed Central

    Maxton, D G; Cynk, E U; Jenkins, A P; Thompson, R P

    1989-01-01

    The presence of food within the small intestinal lumen promotes mucosal cell proliferation. To define the trophic role of triglycerides, three groups of eight female Wistar rats were isocalorically fed for four weeks with either Vivonex, or Vivonex with 50% calorie substitution with an essential fatty acid mixture, or Vivonex with 50% calorie substitution with a saturated fatty acid mixture. Although Vivonex caused greater body weight gain, both essential fatty acids and saturated fatty acids increased small intestinal weight, mucosal weight, protein and DNA overall, and in each of three intestinal segments (proximal, middle and distal), compared with Vivonex. Mucosal indices were similar for essential fatty acids and saturated fatty acids. These results show that triglycerides, regardless of essential fatty acid content, are trophic to the rat small intestinal mucosa. PMID:2806993

  4. Direct observation of the size dependence of Dexter energy transfer from polymer to small PbS quantum dots

    NASA Astrophysics Data System (ADS)

    Zhang, Yating; Xu, Zhangcheng

    2008-08-01

    Small PbS quantum dots (QDs) with diameters ranging from 2.5 to 3 nm were synthesized directly in the conjugated polymer poly[2-methoxy-5-(2'-ethyl-hexyloxy)-p-phenylene vinylene] (MEH-PPV) at 70 °C. To monitor the size dependence of Dexter energy transfer [D. L. Dexter, J. Chem. Phys. 21, 836 (1953)] from MEH-PPV to PbS QDs, the photoluminescence of MEH-PPV is measured for a series of samples with varying QD sizes controlled by the reaction time. A decreased transfer rate is observed for PbS QDs with a diameter of about 2.65 nm due to the minimum overlap between the emission spectrum of MEH-PPV and the 1Se-1Sh and 1Pe-1Sh transitions of PbS QDs.

  5. Effects of small-bodied fish on invertebrate prey and foraging patterns of waterbirds in Aspen Parkland wetlands

    Microsoft Academic Search

    Caroline E. McParland; Cynthia A. Paszkowski

    2006-01-01

    Competition between large-bodied fish and waterbirds for aquatic invertebrates is well documented in oligotrophic lakes. Recent\\u000a evidence suggests that small-bodied fish that colonize eutrophic, hypoxia-prone wetlands such as prairie potholes can also\\u000a reduce aquatic invertebrates, but the effects of these reductions on breeding waterbirds have so far not been directly documented.\\u000a We added brook stickleback (Culaea inconstans) and fathead minnow

  6. Effects of small-bodied fish on invertebrate prey and foraging patterns of waterbirds in Aspen Parkland wetlands

    Microsoft Academic Search

    Caroline E. McParland; Cynthia A. Paszkowski

    Competition between large-bodied fish and waterbirds for aquatic invertebrates is well documented in oligotrophic lakes. Recent\\u000a evidence suggests that small-bodied fish that colonize eutrophic, hypoxia-prone wetlands such as prairie potholes can also\\u000a reduce aquatic invertebrates, but the effects of these reductions on breeding waterbirds have so far not been directly documented.\\u000a We added brook stickleback (Culaea inconstans) and fathead minnow

  7. Direct effects of increasing carbon dioxide on vegetation

    SciTech Connect

    Strain, B R; Cure, J D [eds.

    1985-12-01

    CO/sub 2/ is an essential environmental resource. It is required as a raw material of the orderly development of all green plants. As the availability of CO/sub 2/ increases, perhaps reaching two or three times the concentration prevailing in preindustrial times, plants and all other organisms dependent on them for food will be affected. Humans are releasing a gaseous fertilizer into the global atmosphere in quantities sufficient to affect all life. This volume considers the direct effects of global CO/sub 2/ fertilization on plants and thus on all other life. Separate abstracts have been prepared for individual papers. (ACR)

  8. Giant direct magnetoelectric effect in strained multiferroic heterostructures

    NASA Astrophysics Data System (ADS)

    Janolin, Pierre-Eymeric; Pertsev, Nikolay A.; Sichuga, David; Bellaiche, L.

    2012-04-01

    The direct magnetoelectric (ME) effect mediated by lattice strains induced in a ferroelectric film by a ferromagnetic substrate is evaluated using first-principles-based calculations. To that end, the strain sensitivity of ferroelectric polarization and the film permittivity are calculated as a function of the in-plane biaxial strain for Pb(Zr0.52Ti0.48)O3 films under various depolarizing fields. It is found that the ME voltage coefficient varies nonmonotonically with this strain and may reach giant values exceeding 100 V cm-1 Oe-1 over a strain range that can be controlled through the electrical boundary conditions.

  9. Multiple direct and sequential Auger effect in the rare gases

    SciTech Connect

    Penent, F.; Lablanquie, P.; Palaudoux, J.; Andric, L. [LCP-MR, CNRS et UPMC, 11, rue P. and M. Curie, 75231 Paris (France); Aoto, T.; Ito, K. [Photon Factory, IMSS, KEK, Tsukuba 305-0801 (Japan); Hikosaka, Y. [IMS, Okazaki 444-8585 (Japan); Feifel, R.; Eland, J. H. D. [PTCL, Oxford University, Oxford (United Kingdom)

    2006-01-09

    The use of a magnetic bottle spectrometer with synchrotron radiation allows multi dimensional electron spectroscopy to be performed by detecting in coincidence all electrons (2, 3, 4) ejected in multiple ionization events. Multiple Auger effect following inner-shell ionization can be investigated in this way. Application of the technique to rare gases (Xe 4d and Kr 3d) double Auger decay reveals all the energy pathways involved. The dominant decay path proceeds by Auger cascade through autoionizing states of the doubly charged ion. Processes where 3 electrons are involved are also observed as direct double Auger and as involving precursor Rydberg series.

  10. Episodic acidification of small streams in the northeastern united states: Effects on fish populations

    USGS Publications Warehouse

    Baker, J.P.; Van Sickle, J.; Gagen, C.J.; DeWalle, D.R.; Sharpe, W.E.; Carline, R.F.; Baldigo, B.P.; Murdoch, P.S.; Bath, D.W.; Kretser, W.A.; Simonin, H.A.; Wigington, P.J., Jr.

    1996-01-01

    As part of the Episodic Response Project (ERP), we studied the effects of episodic acidification on fish in 13 small streams in the northeastern United States: four streams in the Adirondack region of New York, four streams in the Catskills, New York, and five streams in the northern Appalachian Plateau, Pennsylvania. In situ bioassays with brook trout (Salvelinus fontinalis) and a forage fish species (blacknose dace (Rhinichthys atratulus], mottled sculpin (Cottus bairdi), or slimy sculpin (Cottus cognatus), depending on the region) measured direct toxicity. Movements of individual brook trout, in relation to stream chemistry, were monitored using radiotelemetry. Electrofishing surveys assessed fish community status and the density and biomass of brook trout in each stream. During low flow, all streams except one had chemical conditions considered suitable for the survival and reproduction of most fish species (median pH 6.0-7.2 during low flow; inorganic Al 100-200 ??g/L. We conclude that episodic acidification can have long-term effects on fish communities in small streams.

  11. Effect of sunflower oil on sheep small intestinal digesta viscosity, composition and amylase activity

    Microsoft Academic Search

    P. S Mir; M Ivan; G. J Mears; B. F Benkel; C. M Ross; S. D Husar; Z Mir

    2002-01-01

    Dietary oil triggers the release of small intestinal hormones; thus we decided to determine the associated effects on digesta viscosity, total dry matter (DM), protein content and amylase activity in the small intestine. These parameters were investigated in small intestinal digesta collected 15min after slaughter from 18 sheep, finished on a diet of (% DM) barley silage, 60; barley grain,

  12. Robust Altitude Control for a Small Helicopter by Considering the Ground Effect Compensation

    E-print Network

    Pota, Himanshu Roy

    Robust Altitude Control for a Small Helicopter by Considering the Ground Effect Compensation Tushar to control the altitude of a small helicopter for hover as well as vertically take-off/landing near ground surface in the presence of strong horizontal wind gusts. A heave motion model of small helicopter

  13. Management effects on colostrogenesis in small ruminants: a review

    Microsoft Academic Search

    N. Castro; J. Capote; R. M. Bruckmaier; A. Argüello

    2011-01-01

    Colostrum feeding in small ruminants is crucial during the first hours after birth due to the lack of Ig transfer during pregnancy via the placenta. In addition the immature immune system of the neonate is slow to produce its own Ig during the first weeks of life. Colostrogenesis, i.e. the transfer of Ig from blood into mammary secretions, starts several

  14. Evaluating the Effect of Information Technology in Small Businesses

    ERIC Educational Resources Information Center

    Newman, Peter

    2010-01-01

    Information technology (IT) has become a strategic vehicle for small businesses to achieve and sustain their competitive advantage. Prior research has suggested that information technology plays an important role in the decision-making process. The purpose of this study is to examine the relationship between organizational IT performance and…

  15. Facilitating Effective Small Group Discussions of Controversial Issues.

    ERIC Educational Resources Information Center

    Hendrix, Jon R.; And Others

    1983-01-01

    Describes four components of a packet of materials designed for small-group discussions on alphafetoprotein (AFP) screening for neural tube defects. Components consist of instructional guidelines for group leader, informational packet on AFP, list of specific discussion questions, and student evaluation form. Copies of these materials are…

  16. Wireless Brainstorming: Overcoming Status Effects in Small Group Decisions

    Microsoft Academic Search

    John Davis; Melora Zaner; Shelly Farnham; Cezary Marcjan; Brenda P. Mccarthy

    2003-01-01

    Social factors, such as status differences, may prevent some members from participating in group decisions. Computerized group decision support systems (GDSSs) can reduce social influences by allowing group members to contribute anonymously and in parallel. This study explores how a simple GDSS on a wireless handheld device can augment face-to-face group decisions. Small groups of men and women brainstormed potential

  17. Test Report: Direct and Indirect Lightning Effects on Composite Materials

    NASA Technical Reports Server (NTRS)

    Evans, R. W.

    1997-01-01

    Lightning tests were performed on composite materials as a part of an investigation of electromagnetic effects on the materials. Samples were subjected to direct and remote simulated lightning strikes. Samples included various thicknesses of graphite filament reinforced plastic (GFRP), material enhanced by expanded aluminum foil layers, and material with an aluminum honeycomb core. Shielding properties of the material and damage to the sample surfaces and joints were investigated. Adding expanded aluminum foil layers and increasing the thickness of GFRP improves the shielding effectiveness against lightning induced fields and the ability to withstand lightning strikes. A report describing the lightning strike tests performed by the U.S. Army Redstone Technical Test Center, Redstone Arsenal, AL, STERT-TE-E-EM, is included as an appendix.

  18. Direct PO optimized dual-offset reflector antennas for small earth stations and for millimeter wave atmospheric sensors

    NASA Astrophysics Data System (ADS)

    Schlobohm, Bernd; Arndt, Fritz; Kless, Juergen

    1992-06-01

    An efficient direct numerical synthesis method for dual-offset reflector antennas is described which is directly based on the physical optics procedure for both reflectors. The reflector surfaces are advantageously characterized in the spatial domain by a two-dimensional Fourier transformation. The method involves an evolution strategy optimization algorithm in order to immediately shape both reflectors so as to generate the desired far field with prescribed criteria. The efficiency of the design method is demonstrated for two computer-optimized dual-offset antenna design examples for space applications. The first is a very compact optimum-shaped Gregorian dual-offset earth-station antenna with high offset angle (70 deg) and small subreflector size (13 wavelengths). It achieved a very low sidelobe attenuation level within the envelope of only 23-25 log theta dBi and low cross-polarization attenuation (38 dB). The second is a shaped dual-offset Cassegrain atmospheric sensor antenna for 200 GHz. It demonstrates that beam scanning by more than 10 half-power beamwidths is possible with nearly constant half-power beamwidth by linearly displacing the subreflector, resulting in a very low mass to be moved.

  19. Direct Effect of Sodium Iodate on Neurosensory Retina

    PubMed Central

    Wang, Jinmei; Iacovelli, Jared; Spencer, Carrie; Saint-Geniez, Magali

    2014-01-01

    Purpose. To systematically characterize the effects of NaIO3 on retinal morphology and function. Methods. NaIO3 at 10, 20, or 30 mg/kg was administered by retro-orbital injection into adult C57BL/6J mice. Phenotypic and functional changes of the retina were assessed at 1, 3, 5, and 8 days postinjection by fundus imaging, optical coherence tomography (OCT), ERG, and histology. Direct NaIO3 cytotoxicity on ARPE-19 and 661W cells was quantified using lactate dehydrogenase (LDH) apoptosis assay. Effect of NaIO3 on RPE and photoreceptor gene expression was assessed in vitro and in vivo by quantitative PCR. Results. While little to no change was observed in the 10 mg/kg NaIO3-injected group, significant retinal anomalies, such as RPE atrophy and retinal thinning, were observed in both 20 and 30 mg/kg NaIO3-injected groups. Gene expression analysis showed rapid downregulation of RPE-specific genes, increase in heme oxygenase 1 expression, and induction of the ratio of Bax to Bcl-2. Electroretinographic response loss and photoreceptor gene repression preceded gross morphological changes. High NaIO3 toxicity on 661W cells was observed in vitro along with reactive oxygen species (ROS) induction. NaIO3 treatment also disrupted oxidative stress, phototransduction, and apoptosis gene expression in 661W cells. Exposure of ARPE-19 cells to NaIO3 increased expression of neurotrophins and protected photoreceptors from direct NaIO3 cytotoxicity. Conclusions. Systematic characterization of changes associated with NaIO3 injection revealed a large variability in the severity of toxicity induced. Treatment with >20 mg/kg NaIO3 induced visual dysfunction associated with rapid suppression of phototransduction genes and induced oxidative stress in photoreceptors. These results suggest that NaIO3 can directly alter photoreceptor function and survival. PMID:24481259

  20. Cerebellar Transcranial Direct Current Stimulation Effects on Saccade Adaptation

    PubMed Central

    van der Geest, Jos N.; Kengne Kamga, Sandra; Verhage, M. Claire; Donchin, Opher; Frens, Maarten A.

    2015-01-01

    Saccade adaptation is a cerebellar-mediated type of motor learning in which the oculomotor system is exposed to repetitive errors. Different types of saccade adaptations are thought to involve distinct underlying cerebellar mechanisms. Transcranial direct current stimulation (tDCS) induces changes in neuronal excitability in a polarity-specific manner and offers a modulatory, noninvasive, functional insight into the learning aspects of different brain regions. We aimed to modulate the cerebellar influence on saccade gains during adaptation using tDCS. Subjects performed an inward (n = 10) or outward (n = 10) saccade adaptation experiment (25% intrasaccadic target step) while receiving 1.5?mA of anodal cerebellar tDCS delivered by a small contact electrode. Compared to sham stimulation, tDCS increased learning of saccadic inward adaptation but did not affect learning of outward adaptation. This may imply that plasticity mechanisms in the cerebellum are different between inward and outward adaptation. TDCS could have influenced specific cerebellar areas that contribute to inward but not outward adaptation. We conclude that tDCS can be used as a neuromodulatory technique to alter cerebellar oculomotor output, arguably by engaging wider cerebellar areas and increasing the available resources for learning. PMID:25821604

  1. [Small-scale, homelike care environments for people with dementia: effects on residents, family caregivers and nursing staff].

    PubMed

    Verbeek, H; Zwakhalen, S M G; van Rossum, E; Kempen, G I J M; Hamers, J P H

    2013-12-01

    Institutional dementia care is increasingly directed towards small-scale and homelike care environments, in The Netherlands as well as abroad. In these facilities, a small number of residents, usually six to eight, live together, and normal daily household activities and social participation are emphasized. In a quasi-experimental study, we studied the effects of small-scale, homelike care environments on residents (n?=?259), family caregivers (n?=?206) and nursing staff (n?=?305). We compared two types of institutional nursing care during a 1 year period (baseline assessment and follow-up measurements at 6 and 12 months): (28) small-scale, homelike care environments and (21) psychogeriatric wards in traditional nursing homes. A matching procedure was applied to increase comparability of residents at baseline regarding functional status and cognition. This study was unable to demonstrate convincing overall effects of small-scale, homelike care facilities. On our primary outcome measures, such as quality of life and behaviour of residents and job satisfaction and motivation of nursing staff, no differences were found with traditional nursing homes. We conclude that small-scale, homelike care environments are not necessarily a better care environment than regular nursing homes and other types of living arrangements should be considered carefully. This provides opportunities for residents and their family caregivers to make a choice which care facility suits their wishes and beliefs best. PMID:24203378

  2. Small-crack effects in high-strength aluminum alloys

    NASA Technical Reports Server (NTRS)

    Newman, J. C., Jr.; Wu, X. R.; Venneri, S. L.; Li, C. G.

    1994-01-01

    The National Aeronautics and Space Administration and the Chinese Aeronautical Establishment participated in a Fatigue and Fracture Mechanics Cooperative Program. The program objectives were to identify and characterize crack initiation and growth of small cracks (10 microns to 2 mm long) in commonly used US and PRC aluminum alloys, to improve fracture mechanics analyses of surface- and corner-crack configurations, and to develop improved life-prediction methods. Fatigue and small-crack tests were performed on single-edgenotch tension (SENT) specimens and large-crack tests were conducted on center-crack tension specimens for constant-amplitude (stress ratios of -1, 0, and 0.5) and Mini-TWIST spectrum loading. The plastic replica method was used to monitor the initiation and growth of small fatigue cracks at the semicircular notch. Crack growth results from each laboratory on 7075-T6 bare and LC9cs clad aluminum alloys agreed well and showed that fatigue life was mostly crack propagation from a material defect (inclusion particles or void) or from the cladding layer. Finite-element and weight-function methods were used to determine stress intensity factors for surface and corner cracks in the SENT specimens. Equations were then developed and used in a crack growth and crack-closure model to correlate small- and large-crack data and to make life predictions for various load histories. The cooperative program produced useful experimental data and efficient analysis methods for improving life predictions. The results should ultimately improve aircraft structural reliability and safety.

  3. Direct evidence for kinetic effects associated with solar wind reconnection

    PubMed Central

    Xu, Xiaojun; Wang, Yi; Wei, Fengsi; Feng, Xueshang; Deng, Xiaohua; Ma, Yonghui; Zhou, Meng; Pang, Ye; Wong, Hon-Cheng

    2015-01-01

    Kinetic effects resulting from the two-fluid physics play a crucial role in the fast collisionless reconnection, which is a process to explosively release massive energy stored in magnetic fields in space and astrophysical plasmas. In-situ observations in the Earth's magnetosphere provide solid consistence with theoretical models on the point that kinetic effects are required in the collisionless reconnection. However, all the observations associated with solar wind reconnection have been analyzed in the context of magnetohydrodynamics (MHD) although a lot of solar wind reconnection exhausts have been reported. Because of the absence of kinetic effects and substantial heating, whether the reconnections are still ongoing when they are detected in the solar wind remains unknown. Here, by dual-spacecraft observations, we report a solar wind reconnection with clear Hall magnetic fields. Its corresponding Alfvenic electron outflow jet, derived from the decouple between ions and electrons, is identified, showing direct evidence for kinetic effects that dominate the collisionless reconnection. The turbulence associated with the exhaust is a kind of background solar wind turbulence, implying that the reconnection generated turbulence has not much developed. PMID:25628139

  4. Direct evidence for kinetic effects associated with solar wind reconnection.

    PubMed

    Xu, Xiaojun; Wang, Yi; Wei, Fengsi; Feng, Xueshang; Deng, Xiaohua; Ma, Yonghui; Zhou, Meng; Pang, Ye; Wong, Hon-Cheng

    2015-01-01

    Kinetic effects resulting from the two-fluid physics play a crucial role in the fast collisionless reconnection, which is a process to explosively release massive energy stored in magnetic fields in space and astrophysical plasmas. In-situ observations in the Earth's magnetosphere provide solid consistence with theoretical models on the point that kinetic effects are required in the collisionless reconnection. However, all the observations associated with solar wind reconnection have been analyzed in the context of magnetohydrodynamics (MHD) although a lot of solar wind reconnection exhausts have been reported. Because of the absence of kinetic effects and substantial heating, whether the reconnections are still ongoing when they are detected in the solar wind remains unknown. Here, by dual-spacecraft observations, we report a solar wind reconnection with clear Hall magnetic fields. Its corresponding Alfvenic electron outflow jet, derived from the decouple between ions and electrons, is identified, showing direct evidence for kinetic effects that dominate the collisionless reconnection. The turbulence associated with the exhaust is a kind of background solar wind turbulence, implying that the reconnection generated turbulence has not much developed. PMID:25628139

  5. The effective field theory of dark matter direct detection

    SciTech Connect

    Fitzpatrick, A. Liam; Katz, Emanuel [Stanford Institute for Theoretical Physics, Stanford University, Stanford, CA 94305 (United States); Haxton, Wick [Dept. of Physics, University of California, and Lawrence Berkeley National Laboratory, Berkeley, 94720 (United States); Lubbers, Nicholas; Xu, Yiming, E-mail: fitzpatr@stanford.edu, E-mail: haxton@berkeley.edu, E-mail: amikatz@buphy.bu.edu, E-mail: nlubbers@bu.edu, E-mail: ymxu@bu.edu [Physics Department, Boston University, Boston, MA 02215 (United States)

    2013-02-01

    We extend and explore the general non-relativistic effective theory of dark matter (DM) direct detection. We describe the basic non-relativistic building blocks of operators and discuss their symmetry properties, writing down all Galilean-invariant operators up to quadratic order in momentum transfer arising from exchange of particles of spin 1 or less. Any DM particle theory can be translated into the coefficients of an effective operator and any effective operator can be simply related to most general description of the nuclear response. We find several operators which lead to novel nuclear responses. These responses differ significantly from the standard minimal WIMP cases in their relative coupling strengths to various elements, changing how the results from different experiments should be compared against each other. Response functions are evaluated for common DM targets — F, Na, Ge, I, and Xe — using standard shell model techniques. We point out that each of the nuclear responses is familiar from past studies of semi-leptonic electroweak interactions, and thus potentially testable in weak interaction studies. We provide tables of the full set of required matrix elements at finite momentum transfer for a range of common elements, making a careful and fully model-independent analysis possible. Finally, we discuss embedding non-relativistic effective theory operators into UV models of dark matter.

  6. Direct evidence for kinetic effects associated with solar wind reconnection

    NASA Astrophysics Data System (ADS)

    Xu, Xiaojun; Wang, Yi; Wei, Fengsi; Feng, Xueshang; Deng, Xiaohua; Ma, Yonghui; Zhou, Meng; Pang, Ye; Wong, Hon-Cheng

    2015-01-01

    Kinetic effects resulting from the two-fluid physics play a crucial role in the fast collisionless reconnection, which is a process to explosively release massive energy stored in magnetic fields in space and astrophysical plasmas. In-situ observations in the Earth's magnetosphere provide solid consistence with theoretical models on the point that kinetic effects are required in the collisionless reconnection. However, all the observations associated with solar wind reconnection have been analyzed in the context of magnetohydrodynamics (MHD) although a lot of solar wind reconnection exhausts have been reported. Because of the absence of kinetic effects and substantial heating, whether the reconnections are still ongoing when they are detected in the solar wind remains unknown. Here, by dual-spacecraft observations, we report a solar wind reconnection with clear Hall magnetic fields. Its corresponding Alfvenic electron outflow jet, derived from the decouple between ions and electrons, is identified, showing direct evidence for kinetic effects that dominate the collisionless reconnection. The turbulence associated with the exhaust is a kind of background solar wind turbulence, implying that the reconnection generated turbulence has not much developed.

  7. Photoacoustic Doppler Effect from Flowing Small Light-Absorbing Particles

    Microsoft Academic Search

    Hui Fang; Konstantin Maslov; Lihong V. Wang

    2007-01-01

    From the flow of a suspension of micrometer-scale carbon particles, the photoacoustic Doppler shift is observed. As predicted theoretically, the observed Doppler shift equals half of that in Doppler ultrasound and does not depend on the direction of laser illumination. This new physical phenomenon provides a basis for developing photoacoustic Doppler flowmetry, which can potentially be used for detecting fluid

  8. The effect of relatively small scale structural features on fluid flow, fluid entrapment, and tectonic dewatering

    NASA Astrophysics Data System (ADS)

    Teas, Philip Allen

    Frequently, analysis of a system concentrates on large features. These are relatively easy to identify and it is easy to believe that the most prominent feature has the greatest impact on a system. During structural analysis of geologic systems, large deformation features are generally more thoroughly studied. However, small scale features occur in greater numbers and are penetrative, therefore providing insight into the behavior of systems that a few large scale features cannot. Penetrative small scale structures also affect large volumes of rock and may significantly alter the rock's physical properties and mechanical behavior. Small scale deformation features and their effect on hydrologic systems is approached in three ways in this thesis. Optical and electron microscopy analyses of cores from the Cascadia accretionary prism reveal pervasive ductile deformation throughout the wedge on a centimeter scale. Faults with thickness on the scale of a millimeter show evidence of failure under low strength conditions and localized fluid and granular flow. This work provides direct support for hypotheses of weak faults and high fluid pressure within prisms. Well log analysis in the Long Beach Unit of the Wilmington oil field illustrates the distribution of strain and juxtaposition of oil reservoirs across a fault with maximum displacement of ˜30 m. Though previously considered too small to impact the hydrologic system, the fault is found to be capable of trapping a 290 m column of oil. Smaller faults identified in this study likely control a flow anisotropy noted during production. Correlation of log and 3D seismic data within the Barbados accretionary prism reveals small faults with tens of meters of displacement and hundreds to thousands of meters of lateral extent. The complex internal prism structure results in discrete changes in the compaction state of accreted sediments. Sediments undergo the majority of deformation within the first few kilometers of the prism, only deep sections continuing to deform within the wedge. Immediately seaward of the prism, small scale deformation features indicate a 90sp° shift in the orientation of maximum principal stress. Though these studies are vastly different in scope and methodology, in each case my concern has been to assess the impact of the smaller scale structural details of a system. I hope that anyone who reads this work comes away with an appreciation for features that are just below our resolution.

  9. Microbiota-independent ameliorative effects of antibiotics on spontaneous th2-associated pathology of the small intestine.

    PubMed

    Han, Daehee; Walsh, Matthew C; Kim, Kwang Soon; Hong, Sung-Wook; Lee, Junyoung; Yi, Jaeu; Rivas, Gloriany; Surh, Charles D; Choi, Yongwon

    2015-01-01

    We have previously generated a mouse model of spontaneous Th2-associated disease of the small intestine called TRAF6?DC, in which dendritic cell (DC)-intrinsic expression of the signaling mediator TRAF6 is ablated. Interestingly, broad-spectrum antibiotic treatment ameliorates TRAF6?DC disease, implying a role for commensal microbiota in disease development. However, the relationship between the drug effects and commensal microbiota status remains to be formally demonstrated. To directly assess this relationship, we have now generated TRAF6?DC bone marrow chimera mice under germ-free (GF) conditions lacking commensal microbiota, and found, unexpectedly, that Th2-associated disease is actually exacerbated in GF TRAF6?DC mice compared to specific pathogen-free (SPF) TRAF6?DC mice. At the same time, broad-spectrum antibiotic treatment of GF TRAF6?DC mice has an ameliorative effect similar to that observed in antibiotics-treated SPF TRAF6?DC mice, implying a commensal microbiota-independent effect of broad-spectrum antibiotic treatment. We further found that treatment of GF TRAF6?DC mice with broad-spectrum antibiotics increases Foxp3+ Treg populations in lymphoid organs and the small intestine, pointing to a possible mechanism by which treatment may directly exert an immunomodulatory effect. To investigate links between the exacerbated phenotype of the small intestines of GF TRAF6?DC mice and local microbiota, we performed microbiotic profiling of the luminal contents specifically within the small intestines of diseased TRAF6?DC mice, and, when compared to co-housed control mice, found significantly increased total bacterial content characterized by specific increases in Firmicutes Lactobacillus species. These data suggest a protective effect of Firmicutes Lactobacillus against the spontaneous Th2-related inflammation of the small intestine of the TRAF6?DC model, and may represent a potential mechanism for related disease phenotypes. PMID:25689829

  10. Microbiota-Independent Ameliorative Effects of Antibiotics on Spontaneous Th2-Associated Pathology of the Small Intestine

    PubMed Central

    Han, Daehee; Walsh, Matthew C.; Kim, Kwang Soon; Hong, Sung-Wook; Lee, Junyoung; Yi, Jaeu; Rivas, Gloriany; Surh, Charles D.; Choi, Yongwon

    2015-01-01

    We have previously generated a mouse model of spontaneous Th2-associated disease of the small intestine called TRAF6?DC, in which dendritic cell (DC)-intrinsic expression of the signaling mediator TRAF6 is ablated. Interestingly, broad-spectrum antibiotic treatment ameliorates TRAF6?DC disease, implying a role for commensal microbiota in disease development. However, the relationship between the drug effects and commensal microbiota status remains to be formally demonstrated. To directly assess this relationship, we have now generated TRAF6?DC bone marrow chimera mice under germ-free (GF) conditions lacking commensal microbiota, and found, unexpectedly, that Th2-associated disease is actually exacerbated in GF TRAF6?DC mice compared to specific pathogen-free (SPF) TRAF6?DC mice. At the same time, broad-spectrum antibiotic treatment of GF TRAF6?DC mice has an ameliorative effect similar to that observed in antibiotics-treated SPF TRAF6?DC mice, implying a commensal microbiota-independent effect of broad-spectrum antibiotic treatment. We further found that treatment of GF TRAF6?DC mice with broad-spectrum antibiotics increases Foxp3+ Treg populations in lymphoid organs and the small intestine, pointing to a possible mechanism by which treatment may directly exert an immunomodulatory effect. To investigate links between the exacerbated phenotype of the small intestines of GF TRAF6?DC mice and local microbiota, we performed microbiotic profiling of the luminal contents specifically within the small intestines of diseased TRAF6?DC mice, and, when compared to co-housed control mice, found significantly increased total bacterial content characterized by specific increases in Firmicutes Lactobacillus species. These data suggest a protective effect of Firmicutes Lactobacillus against the spontaneous Th2-related inflammation of the small intestine of the TRAF6?DC model, and may represent a potential mechanism for related disease phenotypes. PMID:25689829

  11. Small mammals cause non-trophic effects on habitat and associated snails in a native system.

    PubMed

    Huntzinger, Mikaela; Karban, Richard; Maron, John L

    2011-12-01

    Legacy effects occur when particular species or their interactions with others have long-lasting impacts, and they are increasingly recognized as important determinants of ecological processes. However, when such legacy effects have been explicitly explored, they most often involve the long-term direct effects of species on systems, as opposed to the indirect effects. Here, we explore how a legacy of small mammal exclusion on the abundance of a shrub, bush lupine (Lupinus arboreus), influences the abundance of a native land snail (Helminthoglypta arrosa) in coastal prairie and dune habitats in central California. The factors that limit populations of land snails are very poorly known despite the threats to the persistence of this group of species. In grasslands, prior vole (Microtus californicus) exclusion created long-lasting gains in bush lupine abundance, mediated through the seedbank, and was associated with increased snail numbers (10×) compared to control plots where mammals were never excluded. Similar plots in dune habitat showed no difference in snail numbers due to previous mammal exclusion. We tested whether increased competition for food, increased predation, and/or lower desiccation explained the decline in snail numbers in plots with reduced lupine cover. Tethering experiments supported the hypothesis that voles can have long-lasting impacts as ecosystem engineers, reducing woody lupine habitat required for successful aestivation by snails. These results add to a growing list of studies that have found that non-trophic interactions can be limiting to invertebrate consumers. PMID:21691854

  12. Small Sample Size Effects in Statistical Pattern Recognition: Recommendations for Practitioners

    Microsoft Academic Search

    Sarunas Raudys; Anil K. Jain

    1991-01-01

    The effects of sample size on feature selection and error estimation for several types of classifiers are discussed. The focus is on the two-class problem. Classifier design in the context of small design sample size is explored. The estimation of error rates under small test sample size is given. Sample size effects in feature selection are discussed. Recommendations for the

  13. Effects of Small-Group Learning on Transfer: A Meta-Analysis

    ERIC Educational Resources Information Center

    Pai, Hui-Hua; Sears, David A.; Maeda, Yukiko

    2015-01-01

    This study investigated the potential benefit of small-group learning on transfer performance using the method of meta-analysis. Results showed positive support for the hypothesis that small-group learning can increase students' transfer performance (average effect size of 0.30). Unlike reviews of effects of cooperation on learning, this…

  14. Small Space Nuclear Reactors, Closed Brayton Cycle and Effective Moderators

    Microsoft Academic Search

    Z. P. Tilliette

    1990-01-01

    Space nuclear power systems in the range of 10-30 kWe are concerned in this paper. It has been thought advisable to widen the basis for future technical choices within the French preliminary studies in this low power range. In addition to a reference Brayton cycle, NaK-cooled, fast spectrum, 930 K reactor system, a 1130 K, direct cycle, gas-cooled, ZrH moderated

  15. Metastable structures and size effects in small group dynamics

    PubMed Central

    Lauro Grotto, Rosapia; Guazzini, Andrea; Bagnoli, Franco

    2014-01-01

    In his seminal works on group dynamics Bion defined a specific therapeutic setting allowing psychoanalytic observations on group phenomena. In describing the setting he proposed that the group was where his voice arrived. This physical limit was later made operative by assuming that the natural dimension of a therapeutic group is around 12 people. Bion introduced a theory of the group aspects of the mind in which proto-mental individual states spontaneously evolve into shared psychological states that are characterized by a series of features: (1) they emerge as a consequence of the natural tendency of (both conscious and unconscious) emotions to combine into structured group patterns; (2) they have a certain degree of stability in time; (3) they tend to alternate so that the dissolution of one is rapidly followed by the emergence of another; (4) they can be described in qualitative terms according to the nature of the emotional mix that dominates the state, in structural terms by a kind of typical “leadership” pattern, and in “cognitive” terms by a set of implicit expectations that are helpful in explaining the group behavior (i.e., the group behaves “as if” it was assuming that). Here we adopt a formal approach derived from Socio-physics in order to explore some of the structural and dynamic properties of this small group dynamics. We will described data from an analytic DS model simulating small group interactions of agents endowed with a very simplified emotional and cognitive dynamic in order to assess the following main points: (1) are metastable collective states allowed to emerge in the model and if so, under which conditions in the parameter space? (2) can these states be differentiated in structural terms? (3) to what extent are the emergent dynamic features of the systems dependent of the system size? We will finally discuss possible future applications of the quantitative descriptions of the interaction structure in the small group clinical setting. PMID:25071665

  16. Metastable structures and size effects in small group dynamics.

    PubMed

    Lauro Grotto, Rosapia; Guazzini, Andrea; Bagnoli, Franco

    2014-01-01

    In his seminal works on group dynamics Bion defined a specific therapeutic setting allowing psychoanalytic observations on group phenomena. In describing the setting he proposed that the group was where his voice arrived. This physical limit was later made operative by assuming that the natural dimension of a therapeutic group is around 12 people. Bion introduced a theory of the group aspects of the mind in which proto-mental individual states spontaneously evolve into shared psychological states that are characterized by a series of features: (1) they emerge as a consequence of the natural tendency of (both conscious and unconscious) emotions to combine into structured group patterns; (2) they have a certain degree of stability in time; (3) they tend to alternate so that the dissolution of one is rapidly followed by the emergence of another; (4) they can be described in qualitative terms according to the nature of the emotional mix that dominates the state, in structural terms by a kind of typical "leadership" pattern, and in "cognitive" terms by a set of implicit expectations that are helpful in explaining the group behavior (i.e., the group behaves "as if" it was assuming that). Here we adopt a formal approach derived from Socio-physics in order to explore some of the structural and dynamic properties of this small group dynamics. We will described data from an analytic DS model simulating small group interactions of agents endowed with a very simplified emotional and cognitive dynamic in order to assess the following main points: (1) are metastable collective states allowed to emerge in the model and if so, under which conditions in the parameter space? (2) can these states be differentiated in structural terms? (3) to what extent are the emergent dynamic features of the systems dependent of the system size? We will finally discuss possible future applications of the quantitative descriptions of the interaction structure in the small group clinical setting. PMID:25071665

  17. On some thermodynamic effects in small molecular systems

    NASA Astrophysics Data System (ADS)

    Aslyamov, T. F.; Dinariev, O. Yu.

    2014-06-01

    The behavior of a gas-liquid system in a small volume has been studied. In the absence of the thermodynamic limit, the problem has been examined by methods of statistical physics. This allows the use of new mathematical methods previously applied in nuclear physics. Within the modified droplet model of a real gas sandwiched between two extended plates, an additional component of the pressure, which was previously discussed and exhibits characteristic oscillations at change in the volume, has been found. Qualitative coincidence with the previously reported molecular dynamics simulations has been found.

  18. Edge Effects in Four Point Direct Current Potential Drop Measurement

    NASA Astrophysics Data System (ADS)

    Lu, Yi; Bowler, John R.; Zhang, Chongxue; Bowler, Nicola

    2009-03-01

    The four point direct current potential drop (DCPD) technique is used to measure electrical conductivity and crack depth. It is also used, together with Hall voltage measurements, to evaluate carrier concentration and mobility in semiconductors. Here the theory of DCPD is studied for planar structures in which edge effects may have to be taken into account and correction made to ensure accuracy. The current injected at a point on the surface of an infinite plate of finite thickness gives rise to a field that can be expressed as a summation derived using image theory. Because the images are periodic in the direction perpendicular to the plate surface, the field can also be conveniently expressed in the form of a Fourier series. The two basic formulas; image summation and Fourier series, can be modified for the case where the probe points are near the edge of a plate by further applying image theory and summing image/Fourier terms in two dimensions. Both of these approaches agree with measurement results very well.

  19. Table 1: Examples of direct and indirect effects of parasites in biological invasions. Host(s)Parasite(s) system Direct effect of parasite on

    E-print Network

    Holt, Robert D.

    1 Table 1: Examples of direct and indirect effects of parasites in biological invasions. Host(s)­Parasite(s) system Direct effect of parasite on the host(s) Indirect effect and wider impact Example citation increased competitive replacement of reds Tompkins White & Boots 2003; H: Invasive Asian cyprinid fish

  20. Direct and indirect effects of UVA on skin vessel leakiness

    SciTech Connect

    Staberg, B.; Worm, A.M.; Brodthagen, H.; Rossing, N.

    1982-12-01

    By using the suction blister technique we have investigated the leakiness of skin vessels in healthy volunteers after whole-body suberythemogenic doses of UVA radiation (a quadrant on one side of the abdominal skin was shielded with lead-rubber). The accumulation of intravenously injected labeled albumin in blister fluid was slightly elevated 1 day after irradiation and increased significantly 2 days later. The blister concentrations of 4 endogenous plasma proteins (albumin, transferrin, IgG, and alpha 2-macroglobulin) were elevated 1 day after radiation exposure and normalized 2 days later. All changes were equal on irradiated and nonirradiated skin. It is concluded that UVA radiation can induce a continued or biphasic increased leakage of plasma proteins in the skin vessels, due to a humoral rather than to a direct physical effect of the radiation on the vessel walls. It is suggested that an increased microvascular leakiness in organs other than the skin might be present.

  1. Effects of changing canopy directional reflectance on feature selection.

    PubMed

    Smith, J A; Oliver, R E

    1974-07-01

    A Monte Carlo model was used to predict the mean apparent directional reflectance of a simulated plant canopy and the covariance for seven wavelength channels in the visible portion of the spectrum. The non-Lambertian spectral response from Bouteloua gracilis canopies possessing two plant cover densities was simulated for two solar positions. The calculated spectral signatures as a function of look angle were then analyzed using the divergence criteria to select the best two wavelength channels for discrimination. These calculations indicate that different combinations of wavelength channels are appropriate for various sensor look angles, that target signatures have greater statistical separation for some scan angles than others, and that these effects are time varying. PMID:20134516

  2. Effect of nuclear response functions in dark matter direct detection

    NASA Astrophysics Data System (ADS)

    Gresham, Moira I.; Zurek, Kathryn M.

    2014-06-01

    We examine the effect of nuclear response functions, as laid out by Fitzpatrick et al. [J. Cosmol. Astropart. Phys. 02 (2013) 004], on dark matter (DM) direct detection in the context of well-motivated UV completions, including electric and magnetic dipoles, anapole, spin-orbit, and pseudoscalar-mediated DM. Together, these encompass five of the six nuclear responses extracted from the nonrelativistic effective theory of Fitzpatrick et al. [J. Cosmol. Astropart. Phys. 02 (2013) 004] (with the sixth difficult to UV complete), with two of the six combinations corresponding to standard spin-independent and spin-dependent responses. For constraints from existing direct detection experiments, we find that only the COUPP constraint, due to its heavy iodine target with large angular momentum and an unpaired spin, and its large energy range sensitivity, is substantially modified by the new responses compared to what would be inferred using the standard form factors to model the energy dependence of the response. For heavy targets such as xenon and germanium, the behavior of the new nuclear responses as recoil energy increases can be substantially different from that of the standard responses, but this has almost no impact on the constraints derived from experiments such as LUX, XENON100, and CDMS since the maximum nuclear recoil energy detected in these experiments is relatively low. We simulate mock data for 80 and 250 GeV DM candidates utilizing the new nuclear responses to highlight how they might affect a putative signal, and find the new responses are most important for highly momentum-suppressed interactions such as the magnetic dipole or pseudoscalar-mediated interaction when the target is relatively heavy (such as xenon and iodine).

  3. Effects of pointing direction and direction predictability on event-related lateralizations of the EEG

    Microsoft Academic Search

    Isabelle Berndt; Volker H. Franz; Heinrich H Bülthoff; Edmund Wascher

    2002-01-01

    In two experiments, we investigated hemispheric electroencephalography (EEG) differences in 9(12) healthy volunteers during pointing to lateral and central targets. The questions addressed were whether horizontal pointing direction and the predictability of pointing direction modulated hemispheric differences (event-related lateralizations of the EEG=ERLs). To vary pointing direction predictability, targets were displayed either randomly at one of nine different positions on a

  4. A direct arylation-derived DPP-based small molecule for solution-processed organic solar cells

    NASA Astrophysics Data System (ADS)

    Liu, Shi-Yong; Fu, Wei-Fei; Xu, Jing-Qi; Fan, Cong-Cheng; Jiang, Hao; Shi, Minmin; Li, Han-Ying; Chen, Jun-Wu; Cao, Yong; Chen, Hong-Zheng

    2014-01-01

    A diketo-pyrrolo-pyrrole (DPP) oligomer containing three DPP cores (Ph4Th4(DPP)3) was synthesized via direct arylation of C-H bonds (DACH). Ph4Th4(DPP)3 has good solubility in many organic solvents, and shows a broad absorption band from the visible to near-infrared region as well as a field-effect hole mobility as high as 0.006 cm2 V-1 s-1. Solution-processed bulk heterojunction organic solar cells based on blends of Ph4Th4(DPP)3 as electron donor and fullerene derivative as electron acceptor were fabricated. An optimized power conversion efficiency of 3.76% with a high open-circuit voltage of 0.85 V was achieved after finely tuning the morphology by changing the blend ratio and by adding additives. These results indicate that DACH is an effective way to produce ?-conjugated oligomers for organic solar cells.

  5. Effect of water on the chemical stability of amorphous pharmaceuticals: I. Small molecules.

    PubMed

    Ohtake, Satoshi; Shalaev, Evgenyi

    2013-04-01

    Amorphous states, ubiquitous in pharmaceutical products, possess higher tendency for chemical degradation in comparison to crystalline materials. This instability can be further enhanced by water, which is present even in nominally dry systems. It has been increasingly recognized that in addition to the plasticizing effect of lowering the glass transition temperature, water could influence the degradation rates through medium effects (e.g., through change in solvation of the reactants and the transition state) as well as by direct participation in solid-state hydrolytic degradation processes. In the current review, the impact of water on the chemical stability of small molecules is examined, with emphasis on hydrolysis reactions in freeze-dried materials remaining in the glassy state. Quantitative relationships between water content and stability are discussed, including molecular mobility (global and local) and solution-like mechanisms, using the medium effects concept that has been developed for liquid-state reactions. Further progress in this field requires the development of quantitative and mechanistic understanding of the relationship between local mobility and chemical reactivity in amorphous solids, as well as incorporating the learning from solution chemistry on the role of reaction media in chemical processes. PMID:23371547

  6. A review of the direct and indirect effects of neonicotinoids and fipronil on vertebrate wildlife.

    PubMed

    Gibbons, David; Morrissey, Christy; Mineau, Pierre

    2015-01-01

    Concerns over the role of pesticides affecting vertebrate wildlife populations have recently focussed on systemic products which exert broad-spectrum toxicity. Given that the neonicotinoids have become the fastest-growing class of insecticides globally, we review here 150 studies of their direct (toxic) and indirect (e.g. food chain) effects on vertebrate wildlife--mammals, birds, fish, amphibians and reptiles. We focus on two neonicotinoids, imidacloprid and clothianidin, and a third insecticide, fipronil, which also acts in the same systemic manner. Imidacloprid and fipronil were found to be toxic to many birds and most fish, respectively. All three insecticides exert sub-lethal effects, ranging from genotoxic and cytotoxic effects, and impaired immune function, to reduced growth and reproductive success, often at concentrations well below those associated with mortality. Use of imidacloprid and clothianidin as seed treatments on some crops poses risks to small birds, and ingestion of even a few treated seeds could cause mortality or reproductive impairment to sensitive bird species. In contrast, environmental concentrations of imidacloprid and clothianidin appear to be at levels below those which will cause mortality to freshwater vertebrates, although sub-lethal effects may occur. Some recorded environmental concentrations of fipronil, however, may be sufficiently high to harm fish. Indirect effects are rarely considered in risk assessment processes and there is a paucity of data, despite the potential to exert population-level effects. Our research revealed two field case studies of indirect effects. In one, reductions in invertebrate prey from both imidacloprid and fipronil uses led to impaired growth in a fish species, and in another, reductions in populations in two lizard species were linked to effects of fipronil on termite prey. Evidence presented here suggests that the systemic insecticides, neonicotinoids and fipronil, are capable of exerting direct and indirect effects on terrestrial and aquatic vertebrate wildlife, thus warranting further review of their environmental safety. PMID:24938819

  7. Effect of longer battery life on small bowel capsule endoscopy

    PubMed Central

    Ou, George; Shahidi, Neal; Galorport, Cherry; Takach, Oliver; Lee, Terry; Enns, Robert

    2015-01-01

    AIM: To determine if longer battery life improves capsule endoscopy (CE) completion rates. METHODS: A retrospective study was performed at a tertiary, university-affiliated hospital in Vancouver, Canada. Patients who underwent CE with either PillCam™ SB2 or SB2U between 01/2010 and 12/2013 were considered for inclusion. SB2 and SB2U share identical physical dimensions but differ in their battery lives (8 h vs 12 h). Exclusion criteria included history of gastric or small bowel surgery, endoscopic placement of CE, interrupted view of major landmarks due to technical difficulty or significant amount of debris, and repeat CE using same system. Basic demographics, comorbidities, medications, baseline bowel habits, and previous surgeries were reviewed. Timing of major landmarks in CE were recorded, and used to calculate gastric transit time, small bowel transit time, and total recording time. A complete CE study was defined as visualization of cecum. Transit times and completion rates were compared. RESULTS: Four hundred and eight patients, including 208 (51.0%) males, were included for analysis. The mean age was 55.5 ± 19.3 years. The most common indication for CE was gastrointestinal bleeding (n = 254, 62.3%), followed by inflammatory bowel disease (n = 86, 21.1%). There was no difference in gastric transit times (group difference 0.90, 95%CI: 0.72-1.13, P = 0.352) and small bowel transit times (group difference 1.07, 95%CI: 0.95-1.19, P = 0.261) between SB2U and SB2, but total recording time was about 14% longer in the SB2U group (95%CI: 10%-18%, P < 0.001) and there was a corresponding trend toward higher completion rate (88.2% vs 93.2%, OR = 1.78, 95%CI 0.88-3.63, P = 0.111). There was no statistically significant difference in the rates of positive findings (OR = 0.98, 95%CI: 0.64-1.51, P = 0.918). CONCLUSION: Extending the operating time of CE may be a simple method to improve completion rate although it does not affect the rate of positive findings.

  8. Direct and indirect effects of UV-B exposure on litter decomposition: a meta-analysis.

    PubMed

    Song, Xinzhang; Peng, Changhui; Jiang, Hong; Zhu, Qiuan; Wang, Weifeng

    2013-01-01

    Ultraviolet-B (UV-B) exposure in the course of litter decomposition may have a direct effect on decomposition rates via changing states of photodegradation or decomposer constitution in litter while UV-B exposure during growth periods may alter chemical compositions and physical properties of plants. Consequently, these changes will indirectly affect subsequent litter decomposition processes in soil. Although studies are available on both the positive and negative effects (including no observable effects) of UV-B exposure on litter decomposition, a comprehensive analysis leading to an adequate understanding remains unresolved. Using data from 93 studies across six biomes, this introductory meta-analysis found that elevated UV-B directly increased litter decomposition rates by 7% and indirectly by 12% while attenuated UV-B directly decreased litter decomposition rates by 23% and indirectly increased litter decomposition rates by 7%. However, neither positive nor negative effects were statistically significant. Woody plant litter decomposition seemed more sensitive to UV-B than herbaceous plant litter except under conditions of indirect effects of elevated UV-B. Furthermore, levels of UV-B intensity significantly affected litter decomposition response to UV-B (P<0.05). UV-B effects on litter decomposition were to a large degree compounded by climatic factors (e.g., MAP and MAT) (P<0.05) and litter chemistry (e.g., lignin content) (P<0.01). Results suggest these factors likely have a bearing on masking the important role of UV-B on litter decomposition. No significant differences in UV-B effects on litter decomposition were found between study types (field experiment vs. laboratory incubation), litter forms (leaf vs. needle), and decay duration. Indirect effects of elevated UV-B on litter decomposition significantly increased with decay duration (P<0.001). Additionally, relatively small changes in UV-B exposure intensity (30%) had significant direct effects on litter decomposition (P<0.05). The intent of this meta-analysis was to improve our understanding of the overall effects of UV-B on litter decomposition. PMID:23818993

  9. Comparing Direct and Semi-Direct Modes for Speaking Assessment: Affective Effects on Test Takers

    ERIC Educational Resources Information Center

    Qian, David D.

    2009-01-01

    In recent decades, with an increasing application of computer technology to the delivery of oral language proficiency assessment, there have been renewed debates over the appropriateness of two different testing modes, namely, (a) face-to-face, or direct, testing, and (b) person-to-machine, or semi-direct, testing. Previous research conducted in…

  10. Gas exchange dependency on diffusion coefficient: direct /sup 222/Rn and /sup 3/He comparisons in a small lake

    SciTech Connect

    Torgersen, T.; Mathieu, G.; Hesslein, R.H.; Broecker, W.S.

    1982-01-20

    A direct field comparison was conducted to determine the dependency of gas exchange coefficient (k/sub x/) on the diffusion coefficient (D/sub x/). The study also sought to confirm the enhanced vertical exchange properties of limnocorrals and similar enclosures. Gas exchange coefficients for /sup 222/Rn and /sup 3/He were determined in a small northern Ontario lake, using a /sup 226/Ra and /sup 3/H spike to gain the necessary precision. The results indicate that the gas exchange coefficient is functionally dependent on the diffusion coefficient raised to the 1.22/sub -35//sup + > 12/ power (k/sub x/ = f(D/sub x//sup 1.22)), clearly supporting the stagnant film model of gas exchange. Limnocorrals were found to have gas exchange rates up to 1.7 times higher than the whole lake in spite of the observation of more calm surface conditions in the corral than in the open lake. 33 references, 6 figures, 8 tables.

  11. Effect of reabsorbed recombination radiation on the saturation current of direct gap p-n junctions

    NASA Technical Reports Server (NTRS)

    Von Roos, O.; Mavromatis, H.

    1984-01-01

    The application of the radiative transfer theory for semiconductors to p-n homojunctions subject to low level injection conditions is discussed. By virtue of the interaction of the radiation field with free carriers across the depletion layer, the saturation current density in Shockley's expression for the diode current is reduced at high doping levels. The reduction, due to self-induced photon generation, is noticeable for n-type material owing to the small electron effective mass in direct band-gap III-V compounds. The effect is insignificant in p-type material. At an equilibrium electron concentration of 2 x 10 to the 18th/cu cm in GaAs, a reduction of the saturation current density by 15 percent is predicted. It is concluded that realistic GaAs p-n junctions possess a finite thickness.

  12. The Effectiveness of Leadership Development Programs on Small Farm Producers

    E-print Network

    Malone, Allen A.

    2011-10-21

    group in pursuit of a common or organizational goal. This framework, in combination with Maslow?s Hierarchy of Needs, will serve as a platform for measuring the effectiveness of the program. In 1943 Abraham Maslow formulated a needs based framework... ............................................ 15 Figure 2 Flamholtz?s Operational Leadership Effectiveness Overview ................. 19 Figure 3 Maslow?s Hierarchy of Needs Framework .............................................. 20 Figure 4 Malone?s Leadership Development & Delivery...

  13. Local-time effect on small space-time scale

    E-print Network

    V. A. Panchelyuga; V. A. Kolombet; M. S. Panchelyuga; S. E. Shnoll

    2006-10-18

    The paper presents an investigation of local-time effect - one of the manifestations of macroscopic fluctuations phenomena. Was shown the existence of the named effect for longitudinal distance between locations of measurements up to 500 meters. Also a structure of intervals distribution in neighborhood of local-time peak was studied and splitting of the peak was found out. Obtained results lead to conclusion about sharp anisotropy of space-time.

  14. The effective reference frame in perceptual judgments of motion direction.

    PubMed

    Agaoglu, Mehmet N; Herzog, Michael H; Ö?men, Haluk

    2015-02-01

    The retinotopic projection of stimulus motion depends both on the motion of the stimulus and the movements of the observer. In this study, we aimed to quantify the contributions of endogenous (retinotopic) and exogenous (spatiotopic and motion-based) reference frames on judgments of motion direction. We used a variant of the induced motion paradigm and we created different experimental conditions in which the predictions of each reference frame were different. Finally, assuming additive contributions from different reference frames, we used a linear model to account for the data. Our results suggest that the effective reference frame for motion perception emerges from an amalgamation of motion-based, retinotopic and spatiotopic reference frames. In determining the percept, the influence of relative motion, defined by a motion-based reference frame, dominates those of retinotopic and spatiotopic motions within a finite region. We interpret these findings within the context of the Reference Frame Metric Field (RFMF) theory, which states that local motion vectors might have perceptual reference-frame fields associated with them, and interactions between these fields determine the selection of the effective reference frame. PMID:25536467

  15. Final Environmental Assessment and Finding of No Significant Impact: Small-Scale Geothermal Power Plant and Direct-Use Geothermal Application at AmeriCulture Inc., Cotton City, NM

    SciTech Connect

    N /A

    2002-08-27

    The U.S. Department of Energy (DOE) conducted an Environmental Assessment (EA) of the Small-Scale Power Plant and Direct-Use Application at AmeriCulture, Inc. to evaluate potential impacts of construction and operations that would be funded in part by DOE. Small geothermal power plants have the potential for widespread application, but achieving cost-effectiveness in small plant sizes presents a number of challenges. To address these challenges, DOE is supporting the small-scale field verification projects to (1) determine and validate the economics, performance, and operational characteristics of small-scale geothermal electric power plants in different regions. and (2) determine their ability to provide distributed power in order to facilitate their increased use in the western United States. Through the Geothermal Energy Program, DOE is considering providing financial assistance to Exergy, Inc., of Hayward, California, for the development and field verification of a small-scale, approximately 1 megawatt (MVV), geothermal power plant. The proposed power plant would be located upstream of an existing geothermally-heated fish hatchery owned by AmeriCulture, Inc., of Cotton City, NM. DOE is also considering partially funding AmeriCulture, Inc., for a direct-use geothermal application using fluid discharged from the proposed power plant to heat water for the hatchery. The EA addresses the construction and operation of the small-scale, geothermal power plant and the direct use of geothermal fluid exhausted from the geothermal power plant as a heating source for the hatchery. Two system concepts were investigated. The preferred concept involves cascading the spent geothermal fluid from the proposed geothermal power plant to various thermal processes used for fish production. In the second concept, the proposed power plant would not be built, and the fluid from the existing geothermal well would be used for all direct-use operations associated with the project. DOE/NREL will take this opportunity to monitor and evaluate the technical and economic performance of the proposed power plant and the direct-use project. This information will be used to advance the design and use of small-scale geothermal technologies. The funding decision of the DOE is whether or not to partially fund the Proposed Action. The proposed power plant project would be administered and managed by the DOE Golden Field Office. Partial funding for the direct-use application project would be provided through a National Renewable Energy Laboratory (NREL) subcontract with AmeriCulture, Inc. The direct-use application would be managed by NREL.

  16. The Effects of Small Classes on Academic Achievement: The Results of the Tennessee Class Size Experiment

    Microsoft Academic Search

    Barbara Nye; Larry V. Hedges; Spyros Konstantopoulos

    2000-01-01

    The effects of class size on academic achievement have been studied for decades. Although the results of small scale randomized experiments and large-scale econometric studies point to positive effects of small classes, some scholar have seen the evidence as ambiguous. This paper reports analyses of a 4-year, large-scale randomized experiment on the effects of class size, project STAR in Tennessee.

  17. Intestinal hormones and growth factors: Effects on the small intestine

    PubMed Central

    Drozdowski, Laurie; Thomson, Alan BR

    2009-01-01

    There are various hormones and growth factors which may modify the intestinal absorption of nutrients, and which might thereby be useful in a therapeutic setting, such as in persons with short bowel syndrome. In partI, we focus first on insulin-like growth factors, epidermal and transferring growth factors, thyroid hormones and glucocorticosteroids. Part II will detail the effects of glucagon-like peptide (GLP)-2 on intestinal absorption and adaptation, and the potential for an additive effect of GLP2 plus steroids. PMID:19152442

  18. Functional Nanostructures for Effective Delivery of Small Interfering RNA Therapeutics

    PubMed Central

    Hong, Cheol Am; Nam, Yoon Sung

    2014-01-01

    Small interfering RNA (siRNA) has proved to be a powerful tool for target-specific gene silencing via RNA interference (RNAi). Its ability to control targeted gene expression gives new hope to gene therapy as a treatment for cancers and genetic diseases. However, siRNA shows poor pharmacological properties, such as low serum stability, off-targeting, and innate immune responses, which present a significant challenge for clinical applications. In addition, siRNA cannot cross the cell membrane for RNAi activity because of its anionic property and stiff structure. Therefore, the development of a safe, stable, and efficient system for the delivery of siRNA therapeutics into the cytoplasm of targeted cells is crucial. Several nanoparticle platforms for siRNA delivery have been developed to overcome the major hurdles facing the therapeutic uses of siRNA. This review covers a broad spectrum of non-viral siRNA delivery systems developed for enhanced cellular uptake and targeted gene silencing in vitro and in vivo and discusses their characteristics and opportunities for clinical applications of therapeutic siRNA. PMID:25285170

  19. The effect of crystal tilt on high resolution micrographs of small metal particles

    SciTech Connect

    Malm, J.O. [Lund Univ. (Sweden). Dept. of Inorganic Chemistry 2; O`Keefe, M.A. [Lawrence Berkeley Lab., CA (United States)

    1993-01-01

    The structure of small (1.5-5 nm) metal particles has been studied by high resolution transmission electron microscopy. For particles of this size, it is not possible to use tilting techniques (selected area diffraction), which means that the microscopist has to rely on the image when deciding in which direction the particle is viewed. This work points out some of the problems of intuitive determination of the viewing direction. (DLC)

  20. Small effective population size in the long-toed salamander

    Microsoft Academic Search

    W. Chris Funk; David A. Tallmon; Fred W. Allendorf

    1999-01-01

    The effective population sizes ( N e ) of six populations of the long-toed salamander ( Ambystoma macrodactylum ) from Montana and Idaho, USA were estimated from allozyme data from samples collected in 1978, 1996 and 1997 using the temporal allele frequency method. Five of the six estimates ranged from 23 to 207 (mean = 123 ? ? ? ?

  1. FATE AND EFFECTS OF ATRAZINE IN SMALL AQUATIC MICROCOSMS

    EPA Science Inventory

    Using continuous flow aquaria or static beakers and mixed biota communities, the fate and effects of atrazine were determined and the resilience of the systems after the removal of the compound were evaluated. In addition, the response of the different test systems to the herbici...

  2. The shielding effect of small-scale martian surface geometry on ultraviolet flux

    NASA Astrophysics Data System (ADS)

    Moores, J. E.; Smith, P. H.; Tanner, R.; Schuerger, A. C.; Venkateswaran, K. J.

    2007-12-01

    The atmosphere of Mars does little to attenuate incoming ultraviolet (UV) radiation. Large amounts of UV radiation sterilize the hardiest of terrestrial organisms within minutes, and chemically alter the soil such that organic molecules at or near the surface are rapidly destroyed. Thus the survival of any putative martian life near the surface depends to a large extent on how much UV radiation it receives. Variations in small-scale geometry of the surface such as pits, trenches, flat faces and overhangs can have a significant effect on the incident UV flux and may create "safe havens" for organisms and organic molecules. In order to examine this effect, a 1-D radiative transfer sky model with 836 meshed points (plus the Sun) was developed which includes both diffuse and direct components of the surface irradiance. This model derives the variation of UV flux with latitude and an object's Geometric Shielding Ratio (a ratio which describes the geometry of each situation). The best protection is offered by overhangs with flux reduced to a factor of 1.8±0.2×10 of the unprotected value, a reduction which does not vary significantly by latitude. Pits and cracks are less effective with a reduction in UV flux of only up to 4.5±0.5×10 for the modeled scenarios; however, they are more effective for the same geometric shielding ratio than overhangs at high latitudes due to the low height of the Sun in the sky. Lastly, polar faces of rocks have the least effective shielding geometry with at most a 1.1±0.1×10 reduction in UV flux. Polar faces of rocks are most effective at mid latitudes where the Sun is never directly overhead, as at tropical latitudes, and never exposes the back of the rock, as at polar latitudes. In the most favorable cases, UV flux is sufficiently reduced such that organic in-fall could accumulate beneath overhanging surfaces and in pits and cracks. As well, hardy terrestrial microorganisms such as Bacillus pumilus could persist for up to 100 sols on the outer surfaces of typical spacecraft or several tens of martian years in the most shielded surface niches.

  3. Photoacoustic imaging of acupuncture effect in small animals

    PubMed Central

    Li, Tingting; Xu, Xueliang; Chen, Bingzhang; Rong, Jian; Jiang, Huabei

    2015-01-01

    Acupuncture has been a powerful clinical tool for treating chronic diseases. However, there is currently no appropriate method to clarify the therapeutic effect of acupuncture. Here, we use photoacoustic tomography (PAT) to study the effect of acupuncture on mouse brain blood vessels. Ten healthy mice were stimulated with acupuncture needles on two acupoints. PAT images were obtained before and after acupuncture. We report that stimulation of certain acupoints resulted in changes in hemodynamics/blood flow at these points. The results demonstrate that PAT can non-invasively detect blood flow changes in mouse brain under acupuncture. This pilot study shows the potential of PAT as a visualization tool for illuminating the mechanism of acupuncture and promoting its clinical applications. PMID:25780734

  4. Health and environmental effects document for direct coal liquefaction - 1981.

    SciTech Connect

    Mellinger, P.J.; Wilson, B.W.; Mahlum, D.D.; Sever, L.E.; Olsen, A.R.

    1982-09-01

    This document presents initial estimates of potential human health effects from inhalation of nonmethane hydrocarbons (NMHC) that may be released from a future hypothetical industry producing about 600,000 bb1/day of synthetic fuel by direct liquefaction of coal. The assessment approach starts wth general assumptions that are then refined in a tiered sequence that considers available epidemiological, environmental and chemical data. The uncertainties involved in such an evaluation have been quantified where possible at this early stage of health risk analysis. Many surrogate data bases were considered for application to coal liquefaction including coke oven, British gas retort, roofing tar and asphalts, and cigarette smoke. The coke oven data base was selected for this assessment because the chemical and physical nature of coke oven emissions are judged to more closely approximate potential coal liquefaction emissions. Utilizing the extensive epidemiological data base for coke oven workers as a surrogate model, health effects from release of coal liquefaction NMHC may be quantified. This method results in estimates of about 1 x 10/sup -3/ excess cancer deaths/yr to an industrial work force of 7800 persons and 5 x 10/sup -2/ excess cancer deaths/yr in the U.S. population as a whole from NMHC that boil above 600/sup 0/F. Sources of uncertainty in the estimates are listed. Using these uncertainties, it is estimated that from 2 x 10/sup -4/ to 5 x 10/sup -3/ lung cancer deaths/yr may occur in the industrial work force and from 1 x 10/sup -2/ to 2.5 x 10/sup -1/ lung cancer deaths/yr in the U.S. population as a whole. On an individual basis, the excess lifetime risk to occupationally exposed workers is estimated to be 500 times greater than to members of the U.S. public.

  5. Effect of frequency deviance direction on performance and mismatch negativity.

    PubMed

    Karanasiou, Irene S; Papageorgiou, Charalabos; Kyprianou, Miltiades; Tsianaka, Eleni I; Matsopoulos, George K; Ventouras, Errikos M; Uzunoglu, Nikolaos K

    2011-12-01

    The mismatch negativity (MMN) component of the auditory event-related potential is associated with automatic perceptual inference concerning changes in auditory stimulation. Recent studies have addressed the question whether performance and MMN is affected by the direction of frequency deviance. In the present study, the frequency MMN and performance is investigated during an auditory identification task. Specifically, we examined the effect of positive and negative differences between the present stimulus and the previous response frequencies on performance as well as on the characteristics of stimulus-locked ERPs and brain activation maps. The results show that frequency deviants creating mismatch conditions increase the likelihood of error commission. The decrease in performance achieves statistical significance in the case of positive frequency deviants. In the latter case, ERP amplitude values of the Fz electrode at 164 ms after stimulus onset are statistically larger for mismatch as opposed to no-mismatch condition. This corresponds to significance differences in the activation maps at Brodmann area 11, superior frontal gyrus, and the frontal lobe. The present findings revealed dissociations in behavioral and ERP responses in the processing of positive and negative frequency deviance, lending support to the notion that MMN is more sensitive to increments than to decrements in frequency. PMID:22262539

  6. COLONY INVASION OF SMALL HIVE BEETLES: THE EFFECTS OF HONEY BEE TYPE AND ENTRANCE REDUCERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Frake, A. M. & L. I. de Guzman COLONY INVASION OF SMALL HIVE BEETLES: THE EFFECTS OF HONEY BEE TYPE AND ENTRANCE REDUCERS - First detected in Florida in 1998, small hive beetles (SHB) are now found in at least 30 states. Although SHB can kill colonies (Elzen et al., 1999, Apidologie 30: 361-366...

  7. Effects of Glucocorticoid Receptor Small Interfering RNA Delivered Using Poly Lactic-Co-Glycolic Acid Microparticles

    E-print Network

    Salem, Aliasger K.

    Effects of Glucocorticoid Receptor Small Interfering RNA Delivered Using Poly Lactic-Co-Glycolic receptor (GR) small interfering RNA (siRNA) delivered using biodegradable poly(lactic-co-glycolic acid) (PLGA) microparticles on proliferation and differentiation capabilities of human MSC in vitro

  8. Battery Voltage Stability Effects on Small Wind Turbine Energy Capture: Preprint

    Microsoft Academic Search

    D. Corbus; C. Newcomb; E. I. Baring-Gould; S. Friedly

    2002-01-01

    Previous papers on small wind turbines have shown that the ratio of battery capacity to wind capacity (known as battery-wind capacity ratio) for small wind systems with battery storage has an important effect on wind turbine energy output. Data analysis from pilot project performance monitoring has revealed shortcomings in wind turbine energy output up to 75% of expected due to

  9. Relevant Prior Knowledge Moderates the Effect of Elaboration during Small Group Discussion on Academic Achievement

    ERIC Educational Resources Information Center

    Van Blankenstein, Floris M.; Dolmans, Diana H. J. M.; Van der Vleuten, Cees P. M.; Schmidt, Henk G.

    2013-01-01

    This study set out to test whether relevant prior knowledge would moderate a positive effect on academic achievement of elaboration during small-group discussion. In a 2 × 2 experimental design, 66 undergraduate students observed a video showing a small-group problem-based discussion about thunder and lightning. In the video, a teacher asked…

  10. Small worlds and mega-minds: effects of neighborhood topology on particle swarm performance

    Microsoft Academic Search

    James Kennedy

    1999-01-01

    The study manipulated the neighborhood topologies of particle swarms optimizing four test functions. Several social network structures were tested, with “small-world” randomization of a specified number of links. Sociometric structure and the small-world manipulation interacted with function to produce a significant effect on performance

  11. Experimental search of parametric X-ray radiation in a silicon crystal at a small angle near the velocity direction of relativistic electrons

    Microsoft Academic Search

    B. N. Kalinin; G. A. Naumenko; D. V. Padalko; A. P. Potylitsyn; I. E. Vnukov

    2001-01-01

    At the Tomsk synchrotron measurements of X-ray yield for the energies ?=29–53keV emitted in the forward direction from a perfect silicon crystal bombarded by 500-MeV relativistic electrons have been carried out. The contribution of parametric X-ray radiation (PXR) at a small angle near the velocity direction of electrons has not been observed. The possible maximum value of this radiation is

  12. Predicting the effects of shade on water temperature in small streams

    Microsoft Academic Search

    J. Christopher Rutherford; Shane Blackett; Colin Blackett; Laurel Saito

    1997-01-01

    A computer model for stream water temperature was developed, and tested in a small pasture stream near Hamilton, New Zealand. The model quantifies shading by riparian vegetation, hillsides, and stream banks using three coefficients: canopy angle, topography angle, and canopy shade factor. Shade was measured directly and found to vary significantly along the channel. Using the maximum measured shade, a

  13. The Effect of Extra Small Group Session during PBL Implementation on Student's Achievement

    ERIC Educational Resources Information Center

    Khalil, Mahmoud Salah; Al Rukban, Mohammad Othman

    2010-01-01

    Problem based learning (PBL) started to spread in health professions in Saudi Arabia at the beginning of this century. There are several challenges facing its implementation such as defects on interpersonal communications and self-directed learning. These challenges would affect students' performance in small group discussions and their…

  14. Small Molecule Structure Correctors Abolish Detrimental Effects of Apolipoprotein E4 in Cultured Neurons*

    PubMed Central

    Chen, Hung-Kai; Liu, Zhaoping; Meyer-Franke, Anke; Brodbeck, Jens; Miranda, Rene D.; McGuire, James G.; Pleiss, Michael A.; Ji, Zhong-Sheng; Balestra, Maureen E.; Walker, David W.; Xu, Qin; Jeong, Dah-eun; Budamagunta, Madhu S.; Voss, John C.; Freedman, Stephen B.; Weisgraber, Karl H.; Huang, Yadong; Mahley, Robert W.

    2012-01-01

    Apolipoprotein E4 (apoE4), the major genetic risk factor for late onset Alzheimer disease, assumes a pathological conformation, intramolecular domain interaction. ApoE4 domain interaction mediates the detrimental effects of apoE4, including decreased mitochondrial cytochrome c oxidase subunit 1 levels, reduced mitochondrial motility, and reduced neurite outgrowth in vitro. Mutant apoE4 (apoE4-R61T) lacks domain interaction, behaves like apoE3, and does not cause detrimental effects. To identify small molecules that inhibit domain interaction (i.e. structure correctors) and reverse the apoE4 detrimental effects, we established a high throughput cell-based FRET primary assay that determines apoE4 domain interaction and secondary cell- and function-based assays. Screening a ChemBridge library with the FRET assay identified CB9032258 (a phthalazinone derivative), which inhibits domain interaction in neuronal cells. In secondary functional assays, CB9032258 restored mitochondrial cytochrome c oxidase subunit 1 levels and rescued impairments of mitochondrial motility and neurite outgrowth in apoE4-expressing neuronal cells. These benefits were apoE4-specific and dose-dependent. Modifying CB9032258 yielded well defined structure-activity relationships and more active compounds with enhanced potencies in the FRET assay (IC50 of 23 and 116 nm, respectively). These compounds efficiently restored functional activities of apoE4-expressing cells in secondary assays. An EPR binding assay showed that the apoE4 structure correction resulted from direct interaction of a phthalazinone. With these data, a six-feature pharmacophore model was constructed for future drug design. Our results serve as a proof of concept that pharmacological intervention with apoE4 structure correctors negates apoE4 detrimental effects in neuronal cells and could be further developed as an Alzheimer disease therapeutic. PMID:22158868

  15. Are tropical small mammals physiologically vulnerable to Arrhenius effects and climate change?

    PubMed

    Lovegrove, Barry G; Canale, Cindy; Levesque, Danielle; Fluch, Gerhard; Reháková-Petr?, Milada; Ruf, Thomas

    2014-01-01

    There is some urgency in the necessity to incorporate physiological data into mechanistic, trait-based, demographic climate change models. Physiological responses at the individual level provide the mechanistic link between environmental changes and individual performances and hence population dynamics. Here we consider the causal relationship between ambient temperature (Ta) and metabolic rate (MR), namely, the Arrhenius effect, which is directly affected by global warming through increases in average global air temperatures and the increase in the frequency and intensity of extreme climate events. We measured and collated data for several small, free-ranging tropical arboreal mammals and evaluated their vulnerability to Arrhenius effects and putative heat stress associated with climate change. Skin temperatures (Tskin) were obtained from free-ranging tarsiers (Tarsius syrichta) on Bohol Island, Philippines. Core body temperature (Tb) was obtained from the greater hedgehog tenrec (Setifer setosus) and the gray brown mouse lemur (Microcebus ravelobensis) from Ankarafantsika, Madagascar. Tskin for another mouse lemur, Microcebus griseorufus, was obtained from the literature. All four species showed evidence of hyperthermia during the daytime rest phase in the form of either Tskin or Tb that was higher than the normothermic Tb during the nighttime active phase. Potentially, tropical arboreal mammals with the lowest MRs and Tb, such as tarsiers, are the most vulnerable to sustained heat stress because their Tb is already close to Ta. Climate change may involve increases in MRs due to Arrhenius effects, especially during the rest phase or during torpor and hibernation. The most likely outcome of increased Arrhenius effects with climate change will be an increase in energy expenditure at the expense of other critical functions such as reproduction or growth and will thus affect fitness. However, we propose that these hypothetical Arrhenius costs can be, and in some species probably are, offset by the use of hyperthermic daily torpor, that is, hypometabolism at high Ta. PMID:24457919

  16. New Small-Molecule Inhibitors Effectively Blocking Picornavirus Replication

    PubMed Central

    Ford Siltz, Lauren A.; Viktorova, Ekaterina G.; Zhang, Ben; Kouiavskaia, Diana; Dragunsky, Eugenia; Chumakov, Konstantin; Isaacs, Lyle

    2014-01-01

    ABSTRACT Few drugs targeting picornaviruses are available, making the discovery of antivirals a high priority. Here, we identified and characterized three compounds from a library of kinase inhibitors that block replication of poliovirus, coxsackievirus B3, and encephalomyocarditis virus. Using an in vitro translation-replication system, we showed that these drugs inhibit different stages of the poliovirus life cycle. A4(1) inhibited both the formation and functioning of the replication complexes, while E5(1) and E7(2) were most effective during the formation but not the functioning step. Neither of the compounds significantly inhibited VPg uridylylation. Poliovirus resistant to E7(2) had a G5318A mutation in the 3A protein. This mutation was previously found to confer resistance to enviroxime-like compounds, which target a phosphatidylinositol 4-kinase III? (PI4KIII?)-dependent step in viral replication. Analysis of host protein recruitment showed that E7(2) reduced the amount of GBF1 on the replication complexes; however, the level of PI4KIII? remained intact. E7(2) as well as another enviroxime-like compound, GW5074, interfered with viral polyprotein processing affecting both 3C- and 2A-dependent cleavages, and the resistant G5318A mutation partially rescued this defect. Moreover, E7(2) induced abnormal recruitment to membranes of the viral proteins; thus, enviroxime-like compounds likely severely compromise the interaction of the viral polyprotein with membranes. A4(1) demonstrated partial protection from paralysis in a murine model of poliomyelitis. Multiple attempts to isolate resistant mutants in the presence of A4(1) or E5(1) were unsuccessful, showing that effective broad-spectrum antivirals could be developed on the basis of these compounds. IMPORTANCE Diverse picornaviruses can trigger multiple human maladies, yet currently, only hepatitis A virus and poliovirus can be controlled with vaccination. The development of antipicornavirus therapeutics is also facing significant difficulties because these viruses readily generate resistance to compounds targeting either viral or cellular factors. Here, we describe three novel compounds that effectively block replication of distantly related picornaviruses with minimal toxicity to cells. The compounds prevent viral RNA replication after the synthesis of the uridylylated VPg primer. Importantly, two of the inhibitors are strongly refractory to the emergence of resistant mutants, making them promising candidates for further broad-spectrum therapeutic development. Evaluation of one of the compounds in an in vivo model of poliomyelitis demonstrated partial protection from the onset of paralysis. PMID:25008939

  17. A character projection low energy electron beam direct writing system for device of small production lot with a variety of design

    NASA Astrophysics Data System (ADS)

    Nakamura, Fumihiko; Watanabe, Katsuhide; Kinoshita, Hidetoshi; Shinozaki, Hiroyuki; Kojima, Yasushi; Morita, Satoshi; Noguchi, Kouhei; Yamaguchi, Norihiro; Isokawa, Hisashi; Kushitani, Kazuhiko; Satoh, Takayuki; Koshiba, Takeshi; Oota, Takumi; Nakasugi, Tetsuro; Mizuno, Hiroyuki

    2006-03-01

    A character projection (CP)-type, low energy, electron beam direct writing (EBDW) system, for quick-turn-around-time and mask-less device fabrications of small production lots featuring a variety of designs has been developed. This system, named the EBIS (Electron Beam Integrated System), can satisfy a set of requirements for EBDWs, including higher throughput and mask-less exposure. A standardized CP aperture method that enables reduction in the number of EB shots without frequent aperture making has been applied as a means for attaining effective CP and mask-less fabrication. This breakthrough was able to be realized only by using low energy EB with the advantage of the free proximity effect. To resolve critical low energy EB issues, a compact EB column, equipped with monolithic deflectors and lenses for restricting beam blur caused by Coulomb interaction, was developed and put to use. Sufficient resolution, corresponding to 100 nm L/S patterns, was attained by using a thin-layered resist process. As the mark detection method, voltage contrast imaging using a micro channel plate was used. This method made it possible to detect buried marks when using low energy EB. The authors are currently verifying the basic performance of this EBIS. This paper outlines and discusses geometrical details and performance data of this system.

  18. Temporal dynamics of direct reciprocal and indirect effects in a host-parasite network.

    PubMed

    Pilosof, Shai; Fortuna, Miguel A; Vinarski, Maxim V; Korallo-Vinarskaya, Natalia P; Krasnov, Boris R

    2013-09-01

    1. Temporal variation in the direct and indirect influence that hosts and parasites exert on each other is still poorly understood. However, variation in species' influence due to species and interactions turnover can have important consequences for host community dynamics and/or for parasite transmission dynamics, and eventually for the risk of zoonotic diseases. 2. We used data on a network of small mammals and their ectoparasites surveyed over 6 years to test hypotheses exploring (i) the temporal variability in direct and indirect influences species exert on each other in a community, and (ii) the differences in temporal variability of direct/indirect influences between temporally persistent (TP) and temporally intermittent species. 3. We modelled the temporal variation in (i) direct reciprocal influence between hosts and parasites (hosts providing resources to parasites and parasites exploiting the resources of hosts), using an asymmetry index, and (ii) indirect influence among species within a community (e.g. facilitation of parasite infestation by other parasites), using betweenness centrality. We also correlated asymmetry and centrality to examine the relationship between them. 4. Network dynamics was determined by TP species but even those species had strong among-species heterogeneity in the temporal variation of the direct/indirect effects they exerted. In addition, there was a significant positive linear correlation between asymmetry and centrality. 5. We conclude that the temporal dynamics of host-parasite interactions is driven by TP hosts. However, even within this group of persistent species, some exhibit large temporal variation, such that the functional roles they play (e.g. in promoting parasite transmission) change over time. In addition, parasites having a large negative impact on hosts are also those facilitating the spread of other parasites through the entire host community. Our results provide new insights into community dynamics and can be applied in the management of antagonistic networks aimed at preventing disease outbreaks. PMID:23672501

  19. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    10 Energy 3 2010-01-01 2010-01-01 false Small electric motors energy conservation standards and their effective dates. [Reserved] 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION...

  20. Mapping small effect mutations in Saccharomyces cerevisiae: impacts of experimental design and mutational properties

    E-print Network

    Gruber, Jonathan

    1 Mapping small effect mutations in Saccharomyces cerevisiae: impacts responsible for three EMS-induced mutant phenotypes in Saccharomyces cerevisiae of experimental design and mutational properties Fabien Duveau*, Brian P.H. Metzger

  1. Analysis of small scale turbulent structures and the effect of spatial scales on gas transfer

    NASA Astrophysics Data System (ADS)

    Schnieders, Jana; Garbe, Christoph

    2014-05-01

    The exchange of gases through the air-sea interface strongly depends on environmental conditions such as wind stress and waves which in turn generate near surface turbulence. Near surface turbulence is a main driver of surface divergence which has been shown to cause highly variable transfer rates on relatively small spatial scales. Due to the cool skin of the ocean, heat can be used as a tracer to detect areas of surface convergence and thus gather information about size and intensity of a turbulent process. We use infrared imagery to visualize near surface aqueous turbulence and determine the impact of turbulent scales on exchange rates. Through the high temporal and spatial resolution of these types of measurements spatial scales as well as surface dynamics can be captured. The surface heat pattern is formed by distinct structures on two scales - small-scale short lived structures termed fish scales and larger scale cold streaks that are consistent with the footprints of Langmuir Circulations. There are two key characteristics of the observed surface heat patterns: 1. The surface heat patterns show characteristic features of scales. 2. The structure of these patterns change with increasing wind stress and surface conditions. In [2] turbulent cell sizes have been shown to systematically decrease with increasing wind speed until a saturation at u* = 0.7 cm/s is reached. Results suggest a saturation in the tangential stress. Similar behaviour has been observed by [1] for gas transfer measurements at higher wind speeds. In this contribution a new model to estimate the heat flux is applied which is based on the measured turbulent cell size und surface velocities. This approach allows the direct comparison of the net effect on heat flux of eddies of different sizes and a comparison to gas transfer measurements. Linking transport models with thermographic measurements, transfer velocities can be computed. In this contribution, we will quantify the effect of small scale processes on interfacial transport and relate it to gas transfer. References [1] T. G. Bell, W. De Bruyn, S. D. Miller, B. Ward, K. Christensen, and E. S. Saltzman. Air-sea dimethylsulfide (DMS) gas transfer in the North Atlantic: evidence for limited interfacial gas exchange at high wind speed. Atmos. Chem. Phys. , 13:11073-11087, 2013. [2] J Schnieders, C. S. Garbe, W.L. Peirson, and C. J. Zappa. Analyzing the footprints of near surface aqueous turbulence - an image processing based approach. Journal of Geophysical Research-Oceans, 2013.

  2. Effect of Health Literacy on the Utilization of Advance Directives Based on the Health Belief Model

    ERIC Educational Resources Information Center

    Henkelman, Wallace J.

    2010-01-01

    Research has demonstrated that only a small proportion of individuals in the United States complete advance directives as part of their planning for end-of-life care. This study sought to determine if health literacy is a significant factor in advance directive completion as has been posited by previous researchers. Analysis of the data collected…

  3. Effects of focused ion beam milling on the compressive behavior of directionally solidified micropillars and the nanoindentation response of an electropolished surface

    Microsoft Academic Search

    S. Shim; H. Bei; M. K. Miller; G. M. Pharr; E. P. George

    2009-01-01

    Focused ion beam (FIB) milling is the typical method used to fabricate micropillars to study small-scale plasticity and size effects in uniaxial compression. However, FIB milling can introduce defects into the milled pillars. To investigate the effects of FIB damage on mechanical behavior, we tested Mo-alloy micropillars that were FIB milled following directional solidification, and compared their compressive response to

  4. Synergistic effect of polymer and small molecules for high-performance ternary organic solar cells.

    PubMed

    Zhang, Yajie; Deng, Dan; Lu, Kun; Zhang, Jianqi; Xia, Benzheng; Zhao, Yifan; Fang, Jin; Wei, Zhixiang

    2015-02-01

    A ternary blend system with two donors and one acceptor provides an effective route to improve the performance of organic solar cells. A synergistic effect of polymer and small molecules is observed in ternary solar cells, and the power conversion effi ciency (PCE) of the ternary system (8.40%) is higher than those of binary systems based on small molecules (7.48%) or polymers (6.85%). PMID:25655181

  5. Direct ion heating effect on ignition conditions in spheromaks

    Microsoft Academic Search

    Mayo

    1996-01-01

    Fowler et al. recently reported the possibility of Ohmic ignition in spheromaks. In the present work, this case is extended to a two fluid model that includes direct ion heating through turbulent Taylor relaxation mechanisms. The contribution to direct ion heating through this non-Ohmic magnetic dissipation and confinement scaling are quantified through comparison with the latest results from the gun

  6. Whole blood transfusion in small animals: indications and effects.

    PubMed

    Godinho-Cunha, Luís F; Ferreira, Rui M R F; Silvestre-Ferreira, Ana C

    2011-06-01

    Transfusion therapy is a major resource that can improve the patient's capability to overcome the underlying disease. However, the effects of whole blood infusion, and how they affect the patient's outcome, are not yet clear. For this study, a protocol was developed in order to monitor a group of 15 animals (9 dogs, 6 cats) that received a total of 19 transfusions; 3 animals received more than one transfusion each. The most common indications for blood transfusion included acute blood loss (47%), coagulopathy (33%) and other anaemias (20%). The mean pre-transfusion packed cell volume (PCV) of animals with acute blood loss (18%) was higher than in the group of coagulopathy (15%) or other anaemias (15%). The survival rates at 6 days after transfusion were greater in the coagulopathy (80.0%) and other anaemias (66.7%) than in the group of acute blood loss (42.9%). After transfusion, pulse rate ( p <0.01) and platelet count ( p <0.05) decreased significantly, and there was a significant increase in body temperature of the animals that suffered from hypothermia before the transfusion ( p <0.05). Overall survival was predictable based upon posttransfusion body temperature, observed PCV change, the difference between the obtained and the calculated PCV, and administered transfusion volume ( p <0.05). PMID:21670882

  7. Delving into the carbon footprints of Singapore—comparing direct and indirect greenhouse gas emissions of a small and open economic system

    Microsoft Academic Search

    Niels B. Schulz

    2010-01-01

    Small and open economic systems like cities face specific challenges for greenhouse gas accounting. They typically import most of their energy requirements as secondary energy products based on conversion processes which caused emissions elsewhere. Emission estimates therefore already require attention not only to direct on-site activities. Moreover, for a comprehensive approach it is suggested to include upstream and downstream processes

  8. EFFECTS OF TRANSCRANIAL DIRECT CURRENT STIMULATION (tDCS) ON SENSORY EVOKED POTENTIALS: A COMPUTATIONAL MODELING

    E-print Network

    Paris-Sud XI, Université de

    EFFECTS OF TRANSCRANIAL DIRECT CURRENT STIMULATION (tDCS) ON SENSORY EVOKED POTENTIALS/computational modeling approach aimed at studying the effects of transcranial Direct Current Stimulation (t field, transcranial direct current stimulation, tDCS, local field potential, LFP, Evoked potential EP

  9. 26 CFR 1.927(e)-2T - Temporary regulations; effect of boycott participation on FSC and small FSC benefits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Temporary regulations; effect of boycott participation on FSC and small FSC benefits. 1.927(e)-2T Section 1.927(e...Temporary regulations; effect of boycott participation on FSC and small FSC benefits. (a) International...

  10. Target Repression Induced by Endogenous microRNAs: Large Differences, Small Effects

    PubMed Central

    Ninova, Maria; Griffiths-Jones, Sam; Ronshaugen, Matthew

    2014-01-01

    MicroRNAs are small RNAs that regulate protein levels. It is commonly assumed that the expression level of a microRNA is directly correlated with its repressive activity – that is, highly expressed microRNAs will repress their target mRNAs more. Here we investigate the quantitative relationship between endogenous microRNA expression and repression for 32 mature microRNAs in Drosophila melanogaster S2 cells. In general, we find that more abundant microRNAs repress their targets to a greater degree. However, the relationship between expression and repression is nonlinear, such that a 10-fold greater microRNA concentration produces only a 10% increase in target repression. The expression/repression relationship is the same for both dominant guide microRNAs and minor mature products (so-called passenger strands/microRNA* sequences). However, we find examples of microRNAs whose cellular concentrations differ by several orders of magnitude, yet induce similar repression of target mRNAs. Likewise, microRNAs with similar expression can have very different repressive abilities. We show that the association of microRNAs with Argonaute proteins does not explain this variation in repression. The observed relationship is consistent with the limiting step in target repression being the association of the microRNA/RISC complex with the target site. These findings argue that modest changes in cellular microRNA concentration will have minor effects on repression of targets. PMID:25141277

  11. Small high-yielding binary Ti vectors pLSU with co-directional replicons for Agrobacterium tumefaciens-mediated transformation of higher plants.

    PubMed

    Lee, Seokhyun; Su, Guiying; Lasserre, Eric; Aghazadeh, Monty Arta; Murai, Norimoto

    2012-05-01

    Small high-yielding binary Ti vectors of Agrobacterium tumefaciens were constructed to increase the cloning efficiency and plasmid yield in Escherichia coli and A. tumefaciens for transformation of higher plants. We reduced the size of the binary vector backbone to 4566bp with ColE1 replicon (715bp) for E. coli and VS1 replicon (2654bp) for A. tumefaciens, a bacterial kanamycin resistance gene (999bp), and the T-DNA region (152bp). The binary Ti vectors with the truncated VS1 replicon were stably maintained with more than 98% efficiency in A. tumefaciens without antibiotic selection for 4 days of successive transfers. The transcriptional direction of VS1 replicon can be the same as that of ColE1 replicon (co-directional transcription), or opposite (head-on transcription) as in the case of widely used vectors (pPZP or pCambia). New binary vectors with co-directional transcription yielded in E. coli up to four-fold higher transformation frequency than those with the head-on transcription. In A. tumefaciens the effect of co-directional transcription is still positive in up to 1.8-fold higher transformation frequency than that of head-on transcription. Transformation frequencies of new vectors are over six-fold higher than those of pCambia vector in A. tumefaciens. DNA yields of new vectors were three to five-fold greater than pCambia in E. coli. The proper functions of the new T-DNA borders and new plant selection marker genes were confirmed after A. tumefaciens-mediated transformation of tobacco leaf discs, resulting in virtually all treated leaf discs transformed and induced calli. Genetic analysis of kanamycin resistance trait among the progeny showed that the kanamycin resistance and sensitivity traits were segregated into the 3:1 ratio, indicating that the kanamycin resistance genes were integrated stably into a locus or closely linked loci of the nuclear chromosomal DNA of the primary transgenic tobacco plants and inherited to the second generation. PMID:22404832

  12. Palms, peccaries and perturbations: widespread effects of small-scale disturbance in tropical forests

    PubMed Central

    2012-01-01

    Background Disturbance is an important process structuring ecosystems worldwide and has long been thought to be a significant driver of diversity and dynamics. In forests, most studies of disturbance have focused on large-scale disturbance such as hurricanes or tree-falls. However, smaller sub-canopy disturbances could also have significant impacts on community structure. One such sub-canopy disturbance in tropical forests is abscising leaves of large arborescent palm (Arececeae) trees. These leaves can weigh up to 15 kg and cause physical damage and mortality to juvenile plants. Previous studies examining this question suffered from the use of static data at small spatial scales. Here we use data from a large permanent forest plot combined with dynamic data on the survival and growth of > 66,000 individuals over a seven-year period to address whether falling palm fronds do impact neighboring seedling and sapling communities, or whether there is an interaction between the palms and peccaries rooting for fallen palm fruit in the same area as falling leaves. We tested the wider generalisation of these hypotheses by comparing seedling and sapling survival under fruiting and non-fruiting trees in another family, the Myristicaceae. Results We found a spatially-restricted but significant effect of large arborescent fruiting palms on the spatial structure, population dynamics and species diversity of neighbouring sapling and seedling communities. However, these effects were not found around slightly smaller non-fruiting palm trees, suggesting it is seed predators such as peccaries rather than falling leaves that impact on the communities around palm trees. Conversely, this hypothesis was not supported in data from other edible species, such as those in the family Myristicaceae. Conclusions Given the abundance of arborescent palm trees in Amazonian forests, it is reasonable to conclude that their presence does have a significant, if spatially-restricted, impact on juvenile plants, most likely on the survival and growth of seedlings and saplings damaged by foraging peccaries. Given the abundance of fruit produced by each palm, the widespread effects of these small-scale disturbances appear, over long time-scales, to cause directional changes in community structure at larger scales. PMID:22429883

  13. Direct and indirect effects of alpha-particle irradiations of human prostate tumor cells

    E-print Network

    Wang, Rong, Ph. D. Massachusetts Institute of Technology

    2005-01-01

    The objective of this project is to establish a model system to study the direct effect, the bystander effect and the combinational effect of alpha-particle irradiations of human prostate tumor cells, toward the goal of ...

  14. Direct and indirect aerosol effects on the Indian monsoon in the CMIP5 integrations

    NASA Astrophysics Data System (ADS)

    Guo, L.; Highwood, E.; Turner, A. G.

    2013-12-01

    The South Asian monsoon represents one of the most dramatic components of the global climate system and the summer season provides around 80% of annual rainfall to over a billion people in India and surrounding regions. Future climate change projections of the South Asian monsoon based on increased concentrations of greenhouse gases generally suggest small increases in seasonal mean rainfall, due to enhanced availability of moisture from the warmer Indian Ocean. However, rapid population growth and increasing industrialisation in India has led to massive sources of anthropogenic aerosol emission both as sulphate and black carbon (from cooking fires). This is particularly focused on the densely-populated Indo-Gangetic Plains region in northern India, where aerosols accumulate against the Himalayan foothills. In this study we use 20th century historical integrations of the 5th Coupled Model Intercomparison Project (CMIP5). Firstly we compare the subset of models in which greenhouse gases-only and aerosols-only experiments have been performed with the all-forcings integrations. We analyse the spatial pattern of rainfall change from the pre-industrial period to the present day as well as time series of rainfall over South Asia during summer, and show that the aerosol-only experiments more closely match the changes occurring in the all-forcings experiment. This suggests that at their late 20th century concentrations, aerosols play a dominant role over South Asian monsoon rainfall. Next, we examine the all-forcing simulations and compare those models that feature some representation of aerosol indirect effects with those models that consider aerosol direct effects only. In the direct effects-only models, the precipitation change from the pre-industrial period to the present day is shown to be positive over South Asia. However in the indirect effect models, the signal is negative, suggesting the importance of sulphate interactions with low cloud. We also discuss implications for future projections of monsoon rainfall using representative concentration pathways (RCP) of CMIP5.

  15. Effects of scatter modeling on time-activity curves estimated directly from dynamic SPECT projections

    SciTech Connect

    Reutter, Bryan W.; Gullberg, Grant T.; Huesman, Ronald H.

    2003-10-29

    Quantitative analysis of uptake and washout of cardiac single photon emission computed tomography (SPECT) radiopharmaceuticals has the potential to provide better contrast between healthy and diseased tissue, compared to conventional reconstruction of static images. Previously, we used B-splines to model time-activity curves (TACs) for segmented volumes of interest and developed fast least-squares algorithms to estimate spline TAC coefficients and their statistical uncertainties directly from dynamic SPECT projection data. This previous work incorporated physical effects of attenuation and depth-dependent collimator response. In the present work, we incorporate scatter and use a computer simulation to study how scatter modeling affects directly estimated TACs and subsequent estimates of compartmental model parameters. An idealized single-slice emission phantom was used to simulate a 15 min dynamic {sup 99m}Tc-teboroxime cardiac patient study in which 500,000 events containing scatter were detected from the slice. When scatter was modeled, unweighted least-squares estimates of TACs had root mean square (RMS) error that was less than 0.6% for normal left ventricular myocardium, blood pool, liver, and background tissue volumes and averaged 3% for two small myocardial defects. When scatter was not modeled, RMS error increased to average values of 16% for the four larger volumes and 35% for the small defects. Noise-to-signal ratios (NSRs) for TACs ranged between 1-18% for the larger volumes and averaged 110% for the small defects when scatter was modeled. When scatter was not modeled, NSR improved by average factors of 1.04 for the larger volumes and 1.25 for the small defects, as a result of the better-posed (though more biased) inverse problem. Weighted least-squares estimates of TACs had slightly better NSR and worse RMS error, compared to unweighted least-squares estimates. Compartmental model uptake and washout parameter estimates obtained from the TACs were less sensitive to whether or not scatter was modeled, compared to the TACs themselves.

  16. Effective charge of a small absorbing body in highly collisional plasma subject to an external electric field

    SciTech Connect

    Chaudhuri, M.; Khrapak, S. A.; Morfill, G. E. [Max-Planck Institut fuer Extraterrestrische Physik, D-85741 Garching (Germany)

    2007-05-15

    The total force which is the resultant of the electric, ion, and electron drag forces has been calculated for a small absorbing spherical grain immersed in a highly collisional, weakly ionized plasma subject to a weak external electric field. Linear dielectric response formalism has been used and both ion and electron absorption on the grain have been taken into account. It is shown that the total force is always directed along the direction of the electric force. The 'effective' charge of the grain which can be defined as the ratio of the total force to the strength of the electric field is calculated. It is shown that its magnitude is comparable to the magnitude of the actual grain's charge.

  17. The Use of Owner Resources in Small and Family Owned Businesses: Literature Review and Future Research Directions

    Microsoft Academic Search

    Tansel Yilmazer; Holly Schrank

    2010-01-01

    This paper integrates relevant literature and the Sustainable Family Business Model regarding interchange of financial resources\\u000a between family and business. Two distinct literatures on the use of owner resources in small businesses are examined: the\\u000a intermingling of business and household resources from the family firm literature and financial bootstrapping studies from\\u000a the small business finance literature. What has not been

  18. Disentangling direct and indirect effects of experimental grassland management and plant functional-group manipulation on plant and leafhopper diversity

    PubMed Central

    2014-01-01

    Background Plant biodiversity can affect trophic interactions in many ways, including direct bottom-up effects on insects, but is negatively affected by agricultural intensification. Grassland intensification promotes plant productivity, resulting in changes in plant community composition, and impacts on higher trophic levels. Here, we use a novel grassland management experiment combining manipulations of cutting and fertilization with experimental changes in plant functional group composition (independent of management effects) to disentangle the direct and indirect effects of agricultural management on insect herbivore diversity and abundance. We used leafhoppers as model organisms as they are a key insect taxon in grasslands and react rapidly to management changes. Leafhoppers were sampled between May and September 2010 using standardized sweep netting and pan traps. Results Plant diversity, functional group composition and management regime in grasslands affected leafhopper species richness and abundance. Higher cutting frequencies directly led to decreasing leafhopper species richness, presumably due to the higher disturbance frequency and the reduction in food-resource heterogeneity. In contrast, fertilizer application had only a small indirect negative effect via enhanced aboveground plant biomass, reduced plant diversity and changes in functional group composition. The manipulated increase in grass cover had contrasting direct and indirect effects on leafhopper species richness: grass cover directly increased leafhopper species richness, but negatively affected plant diversity, which in turn was positively related to leafhopper species richness. In conclusion, insect diversity is driven in complex direct and indirect ways by grassland management, including changes in functional group composition. Conclusions The availability of preferred food sources and the frequency of disturbance are important direct and indirect drivers of leafhopper species richness, interacting in complex ways with plant diversity and food resource heterogeneity. PMID:24438134

  19. SUITABILITY OF SMALL FISH SPECIES FOR MONITORING THE EFFECTS OF PULP MILL EFFLUENT ON FISH

    E-print Network

    as "sentinels" for monitoring effluent related effects in river environments. The upper Fraser River#12;SUITABILITY OF SMALL FISH SPECIES FOR MONITORING THE EFFECTS OF PULP MILL EFFLUENT ON FISH POPULATIONS OF THE FRASER RIVER DOE FRAP 1995-11 Prepared for: Environment Canada Environmental Conservation

  20. A microfluidic platform for studying the effects of small temperature gradients in an incubator environment

    E-print Network

    Kamm, Roger D.

    A microfluidic platform for studying the effects of small temperature gradients in an incubator Studies on the effects of variations in temperature and mild temperature gradients on cells, gels- pable of controlling temperature gradients in an environment which mimics the range of physiological

  1. Effects of elevated water temperature on fish and macroinvertebrate communities below small dams

    Microsoft Academic Search

    JoAnna L. Lessard; Daniel B. Hayes

    2003-01-01

    Many studies have investigated the ecological changes that occur below dams that release cold, hypolimnetic water, but very few studies have looked at the effects of the release of warm, surface waters. The effect of small, surface release dams on downstream thermal regimes is a major habitat concern for many cold-water systems, however. The objective of this study was to

  2. Effects of ion drift on small-amplitude ion-acoustic solitons

    Microsoft Academic Search

    H. H. Kuehl; C. Y. Zhang

    1991-01-01

    Some properties of small-amplitude ion-acoustic solitons in a plasma consisting of nondrifting electrons and drifting ions are investigated. Electron inertia effects are shown to be considerably more important than relativistic effects. It is also shown that ion-acoustic soliton solutions exist only if the ion drift velocity is less than the electron thermal velocity.

  3. Impacts of greenhouse gases and aerosol direct and indirect effects on clouds and

    E-print Network

    Dufresne, Jean-Louis

    Impacts of greenhouse gases and aerosol direct and indirect effects on clouds and radiation. Besides the direct impact on radiation through the greenhouse effect and scattering of sunlight decreasing the total greenhouse effect in the longwave spectrum and increasing absorption of solar radiation

  4. Effect of Court Dimensions on Players' External and Internal Load during Small-Sided Handball Games.

    PubMed

    Corvino, Matteo; Tessitore, Antonio; Minganti, Carlo; Sibila, Marko

    2014-05-01

    The aim of this study was to investigate the effect of three different court dimensions on the internal and external load during small-sided handball games. Six male amateur handball players took part in this study and participated in three different 8-min 3vs3 (plus goalkeepers) small-sided handball games (each repeated twice). The three court dimensions were 12×24m, 30×15m and 32×16m. Through Global Positioning System devices (SPI pro elite 15Hz, GPSports) and video analysis, the following parameters were recorded: cyclic and acyclic movements (distance covered and number of technical actions executed), heart rate, and rating of perceived exertion (RPE). Total distance travelled increased with court dimensions (885.2m ± 66.6m in 24×12m; 980.0m ± 73.4m in 30×15m; 1095.0m ± 112.9m in 32×16m, p < 0.05). The analysis of distance covered in the four speed zones (0-1.4 m·s(-1); 1.4-3.4 m·s(-1); 3.4-5.2 m·s(-1); >5.2 m·s(-1)) highlighted substantial differences: playing with the 30×15m court in comparison to the 24×12m, the players covered less distance in the first speed zone (p = 0.012; ES = 0.70) and more distance in the second (p = 0.049; ES = 0.73) and third (p = 0.012; ES = 0.51) speed zones. Statistical differences were also found between the 24×12m and 32×16m courts: the players covered more distance in the second and third speed zones (p = 0.013, ES = 0.76; p = 0.023 ES = 0.69) with the 32×16m court in comparison to the 24×12m. There was no significant effect of court dimensions on the technical parameters (number of team actions, passes, piston movements toward goal and defensive activities), the number of specific handball jumps and changes of direction, and the time spent in the different heart rate zones. Considering the average data of all the experimental conditions together (24×12m, 30×15m, 32×16m), a pronounced statistical difference was highlighted between the values in first two HR zones and the last two (p < 0.05; large ES). The rating of perceived exertion was significantly higher during the drill with the 32×16m court compared with the 24×12m one (p < 0.05; ES = 2.34). Our findings indicate that changing court dimensions during small-sided handball games can be used to manipulate both external and internal loads on the players. Key pointsTo cover the specific game demands, more specific training methodologies have been developed in many sport games.Specific game exercises may provide a useful conditioning stimulus, together with technical and tactical training components.Changing court dimensions during small-sided handball games can be used to manipulate both external and internal loads on the players.The high ratio of cyclic activity per minute and the high HR values recorded during SSHGs make this type of drills extremely useful for aerobic power training. PMID:24790482

  5. Direct and indirect effects of understorey bamboo shape tree regeneration niches in a mixed temperate forest.

    PubMed

    Caccia, Fernando D; Chaneton, Enrique J; Kitzberger, Thomas

    2009-10-01

    Plant cover plays a major role in shaping the nature of recruitment microsites through direct (resource mediated) and indirect (consumer mediated) interactions. Understorey plants may differentially affect seedling establishment, thus contributing to regeneration-niche separation among canopy tree species. We examined patterns of early tree seedling survival resulting from interactive effects of understorey bamboo (Chusquea culeou) and resident consumers in a mixed temperate Patagonian forest, Argentina. Newly germinated seedlings of Nothofagus dombeyi and Austrocedrus chilensis were planted in bamboo thickets and non-bamboo patches, with or without small-vertebrate exclosures. We found species-specific patterns of seedling survival in relation to bamboo cover. Nothofagus survival was generally low but increased under bamboo, irrespective of cage treatment. Desiccation stress accounted for most Nothofagus mortality in open, non-bamboo areas. In contrast, Austrocedrus survival was highest in non-bamboo microsites, as most seedlings beneath bamboo were killed by small vertebrates through direct consumption or non-trophic physical damage. There was little evidence for a negative impact of bamboo on tree seedling survival attributable to resource competition. The balance of simultaneous positive and negative interactions implied that bamboo presence facilitated Nothofagus early establishment but inhibited Austrocedrus recruitment via apparent competition. These results illustrate the potential for dominant understorey plants to promote microsite segregation during early stages of recruitment between tree seedlings having different susceptibilities to water stress and herbivory. We recognise, however, that patterns of bamboo-seedling interactions may be conditional on moisture levels and consumer activity during establishment. Hence, both biotic and abiotic heterogeneity in understorey environments should be incorporated into conceptual models of regeneration dynamics and tree coexistence in forest communities. PMID:19590896

  6. Effectiveness of Health and Safety in Small Enterprises: A Systematic Review of Quantitative Evaluations of Interventions

    Microsoft Academic Search

    F. Curtis Breslin; Natasha Kyle; Philip Bigelow; Emma Irvin; Sara Morassaei; Ellen MacEachen; Quenby Mahood; Rachel Couban; Harry Shannon; Benjamin C. Amick

    2010-01-01

    Introduction This systematic review was conducted to identify effective occupational health and safety interventions for small businesses.\\u000a Methods The review focused on peer-reviewed intervention studies conducted in small businesses with 100 or fewer employees, that\\u000a were published in English and several other languages, and that were not limited by publication date. Multidisciplinary members\\u000a of the review team identified relevant articles

  7. Small scale effects on the mechanical behaviors of protein microtubules based on the nonlocal elasticity theory

    SciTech Connect

    Gao, Yuanwen, E-mail: ywgao@lzu.edu.cn [Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education, Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000 (China)] [Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education, Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000 (China); Lei, Fang-Ming [Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education, Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000 (China)] [Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education, Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000 (China)

    2009-09-25

    Based on the nonlocal elastic theory, small scale effects are considered in the investigation of the mechanical properties of protein microtubules. A new prediction formula for the persistence lengths of microtubules with the consideration of the small scale effect is presented. Subsequently, the buckling of microtubules is studied based on a nonlocal elastic beam model. The predicted results of our model indicate that the length-dependence of persistence length is related not only to the shear terms, but also to the small scale effect. The Eular beam model, which is always considered unable to explain the length-dependence of microtubules, can capture the length-dependence of the persistence length of microtubules with the consideration of the small scale effect. The elastic buckling behaviors of microtubules in viscoelastic surrounding cytoplasm are also considered using the nonlocal Timoshenko beam model in this paper, and the results indicate that the small scale effect of microtubules also plays an important role in the buckling of microtubules.

  8. Goal Direction and Effectiveness, Emotional Maturity, and Nuclear Family Functioning

    ERIC Educational Resources Information Center

    Klever, Phillip

    2009-01-01

    Differentiation of self, a cornerstone concept in Bowen theory, has a profound influence over time on the functioning of the individual and his or her family unit. This 5-year longitudinal study tested this hypothesis with 50 developing nuclear families. The dimensions of differentiation of self that were examined were goal direction and…

  9. Effects of Small-Scale Turbulence on Bacteria: A Matter of Size

    Microsoft Academic Search

    A. Malits; F. Peters; C. Marrasé; A. Zoppini; O. Guadayol; M. Alcaraz

    2004-01-01

    We examined the influence of small-scale turbulence and its associated shear on bacterioplankton abundance and cell size. We incubated natural microbial assemblages and bacteria-only fractions and subjected them to treatments with turbulence and additions of mineral nutrients and\\/or organic carbon. Bacterial abundance was not affected directly by turbulence in bacteria-only incubations. In natural microbial assemblage incubations, bacterial concentrations were higher

  10. Direct and quantitative broadband absorptance spectroscopy on small objects using Fourier transform infrared spectrometer and bilayer cantilever probes

    E-print Network

    Hsu, Wei-Chun

    A measurement platform is introduced that combines a bilayer cantilever probe with a Fourier transform infrared spectrometer to measure absolute spectral absorptance between wavelengths of 3??m and 18??m directly and ...

  11. Cryogenic Transmission Electron Microscopy for Direct Observation of Polymer and Small-Molecule Materials and Structures in Solution

    Microsoft Academic Search

    Sheng Zhong; Darrin J. Pochan

    2010-01-01

    The application of cryogenic transmission electron microscopy (cryo-TEM) in the study of molecular self-assembly of amphiphilic macromolecules, lipid\\/surfactants, peptides, and other hybrid material systems is quickly growing in popularity as a standard characterization technique. Cryo-TEM allows the direct visualization of nanostructures and microstructures embedded in a thin film of vitrified solvent at liquid nitrogen temperature. This direct observation technique provides

  12. High-throughput screening identifies small molecules that enhance the pharmacological effects of oligonucleotides

    PubMed Central

    Yang, B.; Ming, X.; Cao, C.; Laing, B.; Yuan, A.; Porter, M. A.; Hull-Ryde, E. A.; Maddry, J.; Suto, M.; Janzen, W. P.; Juliano, R. L.

    2015-01-01

    The therapeutic use of antisense and siRNA oligonucleotides has been constrained by the limited ability of these membrane-impermeable molecules to reach their intracellular sites of action. We sought to address this problem using small organic molecules to enhance the effects of oligonucleotides by modulating their intracellular trafficking and release from endosomes. A high-throughput screen of multiple small molecule libraries yielded several hits that markedly potentiated the actions of splice switching oligonucleotides in cell culture. These compounds also enhanced the effects of antisense and siRNA oligonucleotides. The hit compounds preferentially caused release of fluorescent oligonucleotides from late endosomes rather than other intracellular compartments. Studies in a transgenic mouse model indicated that these compounds could enhance the in vivo effects of a splice-switching oligonucleotide without causing significant toxicity. These observations suggest that selected small molecule enhancers may eventually be of value in oligonucleotide-based therapeutics. PMID:25662226

  13. Effect of Transient Hydrogen Evolution/Oxidation Reactions on the OCV of Direct Methanol Fuel Cells

    E-print Network

    Zhao, Tianshou

    Effect of Transient Hydrogen Evolution/Oxidation Reactions on the OCV of Direct Methanol Fuel Cells of a direct methanol fuel cell DMFC was observed to undergo an overshoot before it stabilized during. Available electronically August 16, 2005. Direct methanol fuel cells DMFCs are considered as a hopeful

  14. Spectral effects on direct-insolation absorptance of five collector coatings

    Microsoft Academic Search

    G. B. Hotchkiss; F. F. Simon; L. C. Burmeister

    1979-01-01

    Absorptances for direct insolation of black chrome, black nickel, copper oxide, and two black zinc conversion selective coatings were calculated for a number of typical solar spectrums. Measured spectral reflectances were used while the effects of atmospheric ozone density, turbidity, and air mass were incorporated in calculated direct solar spectrums. Absorptance variation for direct insolation was found to be of

  15. Effects of air flow directions on composting process temperature profile

    SciTech Connect

    Kulcu, Recep [Akdeniz University, Faculty of Agriculture, Department of Farm Machinery, Antalya (Turkey); Yaldiz, Osman [Akdeniz University, Faculty of Agriculture, Department of Farm Machinery, Antalya (Turkey)], E-mail: yaldiz@akdeniz.edu.tr

    2008-07-01

    In this study, chicken manure mixed with carnation wastes was composted by using three different air flow directions: R1-sucking (downward), R2-blowing (upward) and R3-mixed. The aim was to find out the most appropriate air flow direction type for composting to provide more homogenous temperature distribution in the reactors. The efficiency of each aeration method was evaluated by monitoring the evolution of parameters such as temperature, moisture content, CO{sub 2} and O{sub 2} ratio in the material and dry material losses. Aeration of the reactors was managed by radial fans. The results showed that R3 resulted in a more homogenous temperature distribution and high dry material loss throughout the composting process. The most heterogeneous temperature distribution and the lowest dry material loss were obtained in R2.

  16. Effects of air flow directions on composting process temperature profile.

    PubMed

    Kulcu, Recep; Yaldiz, Osman

    2008-01-01

    In this study, chicken manure mixed with carnation wastes was composted by using three different air flow directions: R1-sucking (downward), R2-blowing (upward) and R3-mixed. The aim was to find out the most appropriate air flow direction type for composting to provide more homogenous temperature distribution in the reactors. The efficiency of each aeration method was evaluated by monitoring the evolution of parameters such as temperature, moisture content, CO(2) and O(2) ratio in the material and dry material losses. Aeration of the reactors was managed by radial fans. The results showed that R3 resulted in a more homogenous temperature distribution and high dry material loss throughout the composting process. The most heterogeneous temperature distribution and the lowest dry material loss were obtained in R2. PMID:17888646

  17. Consumer opinion and effectiveness of direct-to-consumer advertising

    Microsoft Academic Search

    Deborah F. Spake; Mathew Joseph

    2007-01-01

    Purpose – The purpose of the paper is to look at the relationship between attitudes toward direct-to-consumer (DTC) advertising and its impact on consumer requests for a particular drug. Design\\/methodology\\/approach – A sample of 154 consumers completed the survey on-site at a pharmacy while waiting for their prescription(s) to be filled. Based on exploratory research (focus groups), survey items were

  18. HUMIDITY EFFECTS ON THERMAL ATMOSPHERIC TRANSMISSIONS: STUDY OF POTENTIAL EFFECTS OF SMALL HYGROSCOPIC AEROSOL PARTICLES IN THE

    E-print Network

    Salvaggio, Carl

    HUMIDITY EFFECTS ON THERMAL ATMOSPHERIC TRANSMISSIONS: STUDY OF POTENTIAL EFFECTS OF SMALL region. This atmospheric anomaly has been linked to conditions of high environmental humidity for toxicology studies of environmental aerosols, the HUCAPS has the ability to control and vary properties

  19. Effect of Agricultural Practices on Hydrology and Water Chemistry in a Small Irrigated Catchment, Yakima River Basin, Washington

    USGS Publications Warehouse

    McCarthy, Kathleen A.; Johnson, Henry M.

    2009-01-01

    The role of irrigation and artificial drainage in the hydrologic cycle and the transport of solutes in a small agricultural catchment in central Washington's Yakima Valley were explored using hydrologic, chemical, isotopic, age-dating, and mineralogical data from several environmental compartments, including stream water, ground water, overland flow, and streambed pore water. A conceptual understanding of catchment hydrology and solute transport was developed and an inverse end-member mixing analysis was used to further explore the effects of agriculture in this small catchment. The median concentrations of major solutes and nitrates were similar for the single field site and for the catchment outflow site, indicating that the net effects of transport processes for these constituents were similar at both scales. However, concentrations of nutrients were different at the two sites, suggesting that field-scale variations in agricultural practices as well as nearstream and instream biochemical processes are important components of agricultural chemical transformation and transport in this catchment. This work indicates that irrigation coupled with artificial drainage networks may exacerbate the ecological effects of agricultural runoff by increasing direct connectivity between fields and streams and minimizing potentially mitigating effects (denitrification and dilution, for example) of longer subsurface pathways.

  20. Synergistic effect of Wnt modulatory small molecules and an osteoinductive ceramic on C2C12 cell osteogenic differentiation.

    PubMed

    Chen, Sigeng; Ryan, Daniel A; Dwyer, Mary A; Cashman, John R

    2014-10-01

    Although osteoinductive ceramics can induce osteoblast differentiation in vitro and bone regeneration in vivo, their effects rely solely on the limited number of endogenous stem cells. More recently, ceramic carriers seeded with culture-expanded stem cells have been reported as implants capable of in vivo bone formation. However, effective and safe signaling agents that promote cell differentiation to the osteogenic lineage are still needed. In the present report, two osteogenic small-molecules THQ-1a and PP-9 were identified by testing a series of compounds for Runx2 and BMP2 expression in C2C12 cells. Compounds THQ-1a and PP-9 modulated Wnt signaling and enhanced the expression of molecular markers of osteoblast differentiation. To probe the utility of these compounds for use with ceramic cell implants, the effect of THQ-1a and PP-9 on C2C12 cell osteogenic differentiation was investigated in the presence of a tricalcium phosphate (TCP) ceramic. The effect of THQ-1a and PP-9 on markers such as Osteocalcin and Collagen I was significantly increased in the presence of TCP ceramic. Additionally, THQ-1a or PP-9 in the presence of TCP ceramic gave a synergistic increase in alkaline phosphatase activity in the differentiation of C2C12 cells. Taken together, the results suggest an approach to directing cell lineage commitment for bone regeneration by the application of small-molecule osteogenic agents to cells in the presence of osteoinductive ceramics. PMID:24998670

  1. Effect of magnetization direction on irreversible magnet demagnetization in brushless dc motor

    NASA Astrophysics Data System (ADS)

    Kim, Tae Heoung

    2008-04-01

    The magnetization direction of a permanent magnet is an important variable in the design process of a brushless dc motor. This paper describes the effect of the magnetization direction on the various characteristics. Especially, we concentrate on the irreversible demagnetization characteristic of a permanent magnet. Two kinds of magnetization direction (radial and parallel direction) and finite element method are used to analyze the effect. From the simulation and experimental results, we suggest that the radial magnetization direction has more advantage in terms of the irreversible magnet demagnetization.

  2. Improving direct-mapped cache performance by the addition of a small fully-associative cache and prefetch buffers

    Microsoft Academic Search

    Norman P. Jouppi

    1990-01-01

    Projections of computer technology forecast processors with peak performance of 1,000 MIPS in the relatively near future. These processors could easily lose half or more of their performance in the memory hierarchy if the hierarchy design is based on conventional caching techniques. This paper presents hardware techniques to improve the performance of caches. Miss caching places a small fully-associative cache

  3. Effective PSHE Education: Values, Purposes and Future Directions

    ERIC Educational Resources Information Center

    Willis, Ben; Clague, Lucy; Coldwell, Mike

    2013-01-01

    This article explores the perceived effectiveness of personal, social, health and economic (PSHE) education in primary and secondary schools. It outlines the relationship between perceived effectiveness and a range of explanatory factors, linking these to the values and ethos of schools, differing views of the purposes of PSHE education, and…

  4. Enhanced hole carrier transport due to increased intermolecular contacts in small molecule based field effect transistors.

    PubMed

    Dharmapurikar, Satej S; Arulkashmir, Arulraj; Das, Chayanika; Muddellu, Pooja; Krishnamoorthy, Kothandam

    2013-08-14

    Small molecules and oligomers can be synthesized with very high purity and precise molecular weights, but they often do not form uniform thin films while processed from solution. Decreased intermolecular contacts between the small molecules are another disadvantage. To increase the intermolecular contacts in small molecules, we have chosen i-indigo, as one of the conjugated molecular units. The electron poor i-indigo has been connected with electron rich triphenylamine to synthesize a donor-acceptor-donor type small molecule. The propeller shaped triphenylamine helps to increase the solubility of the small molecule as well as isotropic charge transport. The intermolecular spacing between the molecules has been found to be low and did not vary as a function of thermal annealing. This implies that the intermolecular contacts between the small molecules are enhanced, and they do not vary as a function of thermal annealing. Organic field effect transistors (OFET) fabricated using a small molecule exhibited a hole carrier mobility (?) of 0.3 cm(2)/(V s) before thermal annealing. A marginal increase in ? was observed upon thermal annealing at 150 °C, which has been attributed to changes in thin film morphology. The morphology of the thin films plays an important role in charge transport in addition to the intermolecular spacing that can be modulated with a judicious choice of the conjugated molecular unit. PMID:23808768

  5. Similar Mechanisms of Movement Control in Target- and Effect-Directed Actions toward Spatial Goals?

    PubMed Central

    Walter, Andrea M.; Rieger, Martina

    2012-01-01

    Previous research has shown that actions conducted toward temporal targets and temporal effects are controlled in a similar way. To investigate whether these findings also apply to spatially restricted movements we analyzed movement kinematics of continuous reversal movements toward given spatial targets and toward self-produced spatial effects in two experiments. In Experiment 1 target- and effect-directed movements were investigated in three different goal constellations. A spatial target/effect was always presented/produced on one movement side, on the other side either (a) no target/effect, (b) the same target/effect, or (c) a more difficult target/effect was presented/produced. Results showed that both target-directed and effect-directed movements have a typical spatial kinematic pattern and that both can be equally well described by linear functions as suggested by Fitts’ Law. However, effect-directed movements have longer movement times. In Experiment 2 participants performed target-directed movements to the one side and effect-directed movements to the other side of a reversal movement. More pronounced spatial kinematics were observed in effect-directed than in target-directed movements. Together, the results suggest that actions conducted toward spatial targets and spatial effects are controlled in a similar manner. Gradual differences in the kinematic patterns may arise because effects are cognitively more demanding. They may therefore be represented less accurately than targets. However, there was no indication of qualitative differences in the cognitive representations of effects and targets. This strengthens our assumption that both targets and effects play a comparable role in action control: they can both be viewed as goals of an action. Thus, ideomotor theories of action control should incorporate action targets as goals similar to action effects. PMID:23230426

  6. Assessing the effectiveness of direct injection for ocean carbon sequestration under the influence of climate change

    E-print Network

    Jain, Atul K.

    Assessing the effectiveness of direct injection for ocean carbon sequestration under the influence, ISAM-2.5D. Following the OCMIP carbon sequestration protocol, we carried out a series of carbon., and L. Cao (2005), Assessing the effectiveness of direct injection for ocean carbon sequestration under

  7. Direct effects of energy-related air pollutants on plant sexual reproduction

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1987-12-08

    Our completed research program concentrated on the direct in vivo effects of energy-related air pollutants on plant sexual reproduction. Direct air pollution effects on plant sexual reproduction have been studied for SO{sub 2} and NO{sub 2}, two of the three major air pollutants.

  8. Academic Self-Concept and Learning Strategies: Direction of Effect on Student Academic Achievement

    ERIC Educational Resources Information Center

    McInerney, Dennis M.; Cheng, Rebecca Wing-yi; Mok, Magdalena Mo Ching; Lam, Amy Kwok Hap

    2012-01-01

    This study examined the prediction of academic self-concept (English and Mathematics) and learning strategies (deep and surface), and their direction of effect, on academic achievement (English and Mathematics) of 8,354 students from 16 secondary schools in Hong Kong. Two competing models were tested to ascertain the direction of effect: Model A…

  9. BOTULINUM TOXIN A INDUCES DIRECT ANALGESIC EFFECTS IN CHRONIC NEUROPATHIC PAIN

    E-print Network

    Paris-Sud XI, Université de

    BOTULINUM TOXIN A INDUCES DIRECT ANALGESIC EFFECTS IN CHRONIC NEUROPATHIC PAIN D. Ranoux1 , N. Such mechanism may be involved in peripheral neuropathic pain. Methods: A possible direct analgesic effect of BTX-A pain processing was investigated in 29 patients with focal painful neuropathies and mechanical

  10. Trophic Tangles through Time? Opposing Direct and Indirect Effects of an Invasive Omnivore on Stream

    E-print Network

    Carlson, Stephanie

    Trophic Tangles through Time? Opposing Direct and Indirect Effects of an Invasive Omnivore Service, Santa Cruz, California, United States of America Abstract Omnivores can impact ecosystems via opposing direct or indirect effects. For example, omnivores that feed on herbivores and plants could either

  11. Directive Versus Participative Leadership: Two Complementary Approaches to Managing School Effectiveness

    ERIC Educational Resources Information Center

    Somech, Anit

    2005-01-01

    Purpose: The educational literature reflects the widely shared belief that participative leadership has an overwhelming advantage over the contrasting style of directive leadership in organizational and team effectiveness. The purpose of this study was to examine the relative effect of a directive leadership approach as compared with a…

  12. A Longitudinal Twin Study of the Direction of Effects between Psychopathic Personality and Antisocial Behaviour

    ERIC Educational Resources Information Center

    Forsman, Mats; Lichtenstein, Paul; Andershed, Henrik; Larsson, Henrik

    2010-01-01

    Background: Antisocial behaviour may partly develop as a consequence of psychopathic personality. However, neither the direction of effects nor the aetiology of the association has previously been clarified. The aim in this study was to investigate the direction of effects between psychopathic personality and antisocial behaviour, and to…

  13. Effect of g-jitter on Directional Solidification of a Binary Alloy

    NASA Technical Reports Server (NTRS)

    Santiviriyapanich, P.; Benjapiyaporn, C.; Timchenko, V.; deVahlDavis, G.; Leonardi, E.; deGroh, H. C., III

    2000-01-01

    A study of directional solidification of a weak binary alloy (specifically, Bi - 1 at% Sn) based on the fixed grid single domain approach is being undertaken. The enthalpy method is used to solve for the temperature field over the computational domain including both the solid and liquid phases; latent heat evolution is treated with the aid of an effective specific heat coefficient. A source term accounting for the release of solute into the liquid during solidification has been incorporated into the solute transport equation. The vorticity-stream function formulation is used to describe thermosolutal convection in the liquid region. In this paper we present a numerical simulation of g-jitter: the small, rapid fluctuations in gravitational acceleration which may be experienced in an orbiting space vehicle. A background gravity of 1 micro-g has been assumed, and new results for the effects of orientation angle of the periodic disturbances over a range of amplitudes and frequencies on solute field and segregation have been presented.

  14. The effect of dissipation in direct communication scheme

    E-print Network

    Fu Li; Jun-Xiang Zhang; Shi-Yao Zhu

    2014-10-11

    The effect of the dissipation and finite number of beam splitters are discussed. A method using balanced dissipation to improve the communication for finite beam splitters, which greatly increases communication reliability with an expense of decreasing communication efficiency.

  15. Direct and semi-direct aerosol radiative effect on the Mediterranean climate variability using a coupled regional climate system model

    NASA Astrophysics Data System (ADS)

    Nabat, Pierre; Somot, Samuel; Mallet, Marc; Sevault, Florence; Chiacchio, Marc; Wild, Martin

    2015-02-01

    A fully coupled regional climate system model (CNRM-RCSM4) has been used over the Mediterranean region to investigate the direct and semi-direct effects of aerosols, but also their role in the radiation-atmosphere-ocean interactions through multi-annual ensemble simulations (2003-2009) with and without aerosols and ocean-atmosphere coupling. Aerosols have been taken into account in CNRM-RCSM4 through realistic interannual monthly AOD climatologies. An evaluation of the model has been achieved, against various observations for meteorological parameters, and has shown the ability of CNRM-RCSM4 to reproduce the main patterns of the Mediterranean climate despite some biases in sea surface temperature (SST), radiation and cloud cover. The results concerning the aerosol radiative effects show a negative surface forcing on average because of the absorption and scattering of the incident radiation. The SW surface direct effect is on average -20.9 Wm-2 over the Mediterranean Sea, -14.7 Wm-2 over Europe and -19.7 Wm-2 over northern Africa. The LW surface direct effect is weaker as only dust aerosols contribute (+4.8 Wm-2 over northern Africa). This direct effect is partly counterbalanced by a positive semi-direct radiative effect over the Mediterranean Sea (+5.7 Wm-2 on average) and Europe (+5.0 Wm-2) due to changes in cloud cover and atmospheric circulation. The total aerosol effect is consequently negative at the surface and responsible for a decrease in land (on average -0.4 °C over Europe, and -0.5 °C over northern Africa) and sea surface temperature (on average -0.5 °C for the Mediterranean SST). In addition, the latent heat loss is shown to be weaker (-11.0 Wm-2) in the presence of aerosols, resulting in a decrease in specific humidity in the lower troposphere, and a reduction in cloud cover and precipitation. Simulations also indicate that dust aerosols warm the troposphere by absorbing solar radiation, and prevent radiation from reaching the surface, thus stabilizing the troposphere. The comparison with the model response in atmosphere-only simulations shows that these feedbacks are attenuated if SST cannot be modified by aerosols, highlighting the importance of using coupled regional models over the Mediterranean. Oceanic convection is also strengthened by aerosols, which tends to reinforce the Mediterranean thermohaline circulation. In parallel, two case studies are presented to illustrate positive feedbacks between dust aerosols and regional climate. First, the eastern Mediterranean was subject to high dust aerosol loads in June 2007 which reduce land and sea surface temperature, as well as air-sea humidity fluxes. Because of northern wind over the eastern Mediterranean, drier and cooler air has been consequently advected from the sea to the African continent, reinforcing the direct dust effect over land. On the contrary, during the western European heat wave in June 2006, dust aerosols have contributed to reinforcing an important ridge responsible for dry and warm air advection over western Europe, and thus to increasing lower troposphere (+0.8 °C) and surface temperature (+0.5 °C), namely about 15 % of this heat wave.

  16. Type curve analyses of pneumatic single-hole tests in unsaturated fractured tuff: Direct evidence for a porosity scale effect

    NASA Astrophysics Data System (ADS)

    Illman, Walter A.

    2005-04-01

    A large number of single- and cross-hole pneumatic injection tests have been conducted in shallow vertical and inclined boreholes in unsaturated fractured tuff at the Apache Leap Research Site (ALRS) near Superior, Arizona. Previously, direct and indirect evidence for a permeability scale effect was provided through the analysis of these tests. Direct evidence was based on the comparison of small-scale single-hole and larger-scale cross-hole test results obtained through the type curve and steady state analysis of these data separately. Indirect evidence was provided by comparing cross-hole test analyses conducted at fine and coarse scales of resolution by means of a three-dimensional numerical inverse model. The latter study also provided indirect evidence for a porosity scale effect. However, there were no small-scale porosity data from single-hole tests to directly verify this indirect evidence. This paper presents such data generated through the type curve interpretation of the recovery phase of the single-hole tests conducted at a nominal 1-m scale providing direct evidence for a porosity scale effect at the site. Statistical analysis of results revealed a strong porosity scale effect confirming an earlier finding obtained indirectly. These results also showed that (1) the injection phase of the pneumatic single-hole tests do not yield reliable estimates of porosity but the recovery phase are amenable to type curve interpretation, (2) flow dimensionality of single-hole tests at 1-m scale are three-dimensional across the site except for a few tests which exhibited two-dimensional and fracture flow behavior, (3) there is a very weak correlation between permeability and porosity, and (4) there is a lack of correlation between fracture density and both permeability and porosity.

  17. Specific Microbiota Direct the Differentiation of IL17-Producing T-Helper Cells in the Mucosa of the Small Intestine

    Microsoft Academic Search

    Ivaylo I. Ivanov; Rosa de Llanos Frutos; Nicolas Manel; Keiji Yoshinaga; Daniel B. Rifkin; R. Balfour Sartor; B. Brett Finlay; Dan R. Littman

    2008-01-01

    SUMMARY The requirements for in vivo steady state differentia- tion of IL-17-producing T-helper (Th17) cells, which are potent inflammation effectors, remain obscure. We report that Th17 cell differentiation in the lamina propria (LP) of the small intestine requires specific commensal microbiota and is inhibited by treating mice with selective antibiotics. Mice from different sources had marked differences in their Th17

  18. New framework for analyzing the effects of small scale inhomogeneities in cosmology

    NASA Astrophysics Data System (ADS)

    Green, Stephen R.; Wald, Robert M.

    2011-04-01

    We develop a new, mathematically precise framework for treating the effects of nonlinear phenomena occurring on small scales in general relativity. Our approach is an adaptation of Burnett’s formulation of the shortwave approximation, which we generalize to analyze the effects of matter inhomogeneities as well as gravitational radiation. Our framework requires the metric to be close to a background metric, but allows arbitrarily large stress-energy fluctuations on small scales. We prove that, within our framework, if the matter stress-energy tensor satisfies the weak energy condition (i.e., positivity of energy density in all frames), then the only effect that small-scale inhomogeneities can have on the dynamics of the background metric is to provide an effective stress-energy tensor that is traceless and has positive energy density—corresponding to the presence of gravitational radiation. In particular, nonlinear effects produced by small-scale inhomogeneities cannot mimic the effects of dark energy. We also develop perturbation theory off of the background metric. We derive an equation for the long-wavelength part of the leading order deviation of the metric from the background metric, which contains the usual terms occurring in linearized perturbation theory plus additional contributions from the small-scale inhomogeneities. Under various assumptions concerning the absence of gravitational radiation and the nonrelativistic behavior of the matter, we argue that the short-wavelength deviations of the metric from the background metric near a point x should be accurately described by Newtonian gravity, taking into account only the matter lying within a homogeneity length scale of x. Finally, we argue that our framework should provide an accurate description of the actual universe.

  19. Small group effectiveness in a Caribbean medical school’s problem-based learning sessions

    PubMed Central

    2014-01-01

    Purpose: The Tutorial Group Effectiveness Instrument was developed to provide objective information on the effectiveness of small groups. Student perception of small group effectiveness during the problem base learning (PBL) process has not been previously studied in Xavier University School of Medicine (Aruba, Kingdom of the Netherlands); hence, the present study was carried out. Methods: The study was conducted among second and third semester undergraduate medical students during the last week of September 2013, at Xavier University School of Medicine of the Netherlands. Students were informed about the objectives of the study and invited to participate after obtaining written, informed consent. Demographic information like gender, age, nationality, and whether the respondent had been exposed to PBL before joining the institution was noted. Student perception about small group effectiveness was studied by noting their degree of agreement with a set of 19 statements using a Likert-type scale. Results: Thirty-four of the 37 (91.9%) second and third semester medical students participated in the study. The mean cognitive score was 3.76 while the mean motivational and de-motivational scores were 3.65 and 2.51, respectively. The median cognitive category score was 27 (maximum score 35) while the motivation score was 26 (maximum score 35) and the de-motivational score was 12 (maximum score25). There was no significant difference in scores according to respondents’ demographic characteristics. Conclusion: Student perception about small group effectiveness was positive. Since most medical schools worldwide already have or are introducing PBL as a learning modality, the Tutorial Group Effectiveness Instrument can provide valuable information about small group functioning during PBL sessions. PMID:24699510

  20. Site-directed mutations within the core "alpha-crystallin" domain of the small heat-shock protein, human alphaB-crystallin, decrease molecular chaperone functions.

    PubMed

    Muchowski, P J; Wu, G J; Liang, J J; Adman, E T; Clark, J I

    1999-06-01

    Site-directed mutagenesis was used to evaluate the effects on structure and function of selected substitutions within and N-terminal to the core "alpha-crystallin" domain of the small heat-shock protein (sHsp) and molecular chaperone, human alphaB-crystallin. Five alphaB-crystallin mutants containing single amino acid substitutions within the core alpha-crystallin domain displayed a modest decrease in chaperone activity in aggregation assays in vitro and in protecting cell viability of E. coli at 50 degrees C in vivo. In contrast, seven alphaB-crystallin mutants containing substitutions N-terminal to the core alpha-crystallin domain generally resembled wild-type alphaB-crystallin in chaperone activity in vitro and in vivo. Size-exclusion chromatography, ultraviolet circular dichroism spectroscopy and limited proteolysis were used to evaluate potential structural changes in the 12 alphaB-crystallin mutants. The secondary, tertiary and quaternary structures of mutants within and N-terminal to the core alpha-crystallin domain were similar to wild-type alphaB-crystallin. SDS-PAGE patterns of chymotryptic digestion were also similar in the mutant and wild-type proteins, indicating that the mutations did not introduce structural modifications that altered the exposure of proteolytic cleavage sites in alphaB-crystallin. On the basis of the similarities between the sequences of human alphaB-crystallin and the sHsp Mj HSP16.5, the only sHsp for which there exists high resolution structural information, a three-dimensional model for alphaB-crystallin was constructed. The mutations at sites within the core alpha-crystallin domain of alphaB-crystallin identify regions that may be important for the molecular chaperone functions of sHsps. PMID:10366513

  1. Synergistic Effect of Phenformin in Non-Small Cell Lung Cancer (NSCLC) Ionizing Radiation Treatment.

    PubMed

    Wang, Jia; Xia, Shi'an; Zhu, Zhizhen

    2015-03-01

    Biguanides, used for anti-diabetic drugs, bring more attention in cancer research for their beneficial effects. Phenformin is more potent than metformin. However its potential application as a anti-cancer regent is far behind metformin. In order to investigate any beneficial effect of combination of Phenformin and radiotherapy, non-small cell lung cancer cell lines A549 and H1299 were exposure under different dose of ionizing radiation with or without Phenformin. Results indicated Phenformin showed synergistic effect and could induce more cancer cell apoptosis and inhibition of tumor growth compared with ionizing radiation alone. Furthermore, this synergistic effect may be through different pathway according to cancer cell genotype background. Our results showed Phenformin induced AMPK activation in A549 but not H1299. However, Phenformin activated eIF2? in both cell lines. Our findings implicated Phenformin may be used as radiosensitizer for non-small cell lung cancer therapy. PMID:25312480

  2. The effect of parasitic diseases on nutrient metabolism and productivity in small ruminants

    Microsoft Academic Search

    O. O. Akinbamijo

    1994-01-01

    INTRODUCTION<\\/strong>The investigation of voluntary feed intake (VFI) and nitrogen retention (NRET) during parasitic infections in small ruminants is the central theme of this thesis. An attempt was made to examine the effects of trypanosomiasis on feed intake, digestibility, nitrogen retention and animal products. In addition, a similar investigation was conducted during a low to medium level fascioliasis infection in Menz

  3. Possible Effects of Small-Scale Intermittency in Turbulent Reacting Flows

    Microsoft Academic Search

    K. R. Sreenivasan

    2004-01-01

    It is now well established that quantities such as energy dissipation, scalar dissipation and enstrophy possess huge fluctuations in turbulent flows, and that the fluctuations become increasingly stronger with increasing Reynolds number of the flow. The effects of this small-scale “intermittenc” on various aspects of reacting flows have not been addressed fully. This paper draws brief attention to a few

  4. Combination muffler is more effective than reactive muffler even in small size

    Microsoft Academic Search

    S. Biswas

    2010-01-01

    Insertion loss of muffler mainly depends on proper selection of muffler volume which is proportional to Engine Swept volume. Thus, use of combination muffler is exceptionally rare in car segments (i.e. - low specific output engines) though it is more effective than other two main categories of mufflers namely Reactive and absorptive respectively. Perhaps configure the small volume is difficult

  5. Effects of a community restoration fire on small mammals and herpetofauna in the southern Appalachians

    Microsoft Academic Search

    William M. Ford; M. Alex Menzel; David W. McGill; Joshua Laerm; Timothy S. McCay

    1999-01-01

    As part of the Wine Spring Creek ecosystem management project on the Nantahala National forest, North Carolina, we assessed effects of a community restoration fire on small mammals and herpetofauna in the upper slope pitch pine (Pinus rigida) stands, neighboring midslope oak (Quercus spp.) stands and rhododendron (Rhododendron maximum) dominated riparian areas during 1995 and 1996. Using drift-fence arrays with

  6. Effect of small additions of rare-earth metal oxides on the properties of lithium ferrite

    Microsoft Academic Search

    M. P. Dimitrova; G. N. Revnyuk

    1973-01-01

    Ways of improving the characteristics of thermally stable square-loop ferrites based on lithium ferrite have been investigated by a number of authors. The synthesis of such ferrites can be improved, it is claimed, by employing additional heat treatment and intensified milling [1] and,even more effectively, by introducing small amounts of fluxes [2, 3] which lower the sintering temperature and ensure

  7. Effects of small sediment barrier removal on geomorphic complexity and habitat diversity

    Microsoft Academic Search

    J. P. Zunka; D. Tullos; S. T. Lancaster

    2009-01-01

    Dam removals can remobilize large volumes of sediment into channels, and the effects of these sediment pulses on channels downstream remain poorly understood. With increasing frequency of barrier removal, it is critical to understand what impacts the barrier removal may have on ecological integrity. In this study, we examine how a small barrier removal on the Calapooia River (Brownsville, OR)

  8. Effects of predator removal on vertebrate prey populations: birds of prey and small mammals

    Microsoft Academic Search

    Kai Norrdahl; Erkki Korpimäki

    1995-01-01

    We studied the effects of removal of breeding nomadic avian predators (the kestrel, Falco tinnunculus and Tengmalm's owl, Aegolius funereus) on small mammals (voles of the genera Microtus and Clethrionomys and the common shrew, Sorex araneus) during 1989–1992 in western Finland to find out if these predators have a regulating or limiting impact on their prey populations. We removed potential

  9. EFFECTS OF DIET ON THE MOTILITY OF THE SMALL INTESTINE AND PLASMA INSULIN LEVELS IN SHEEP

    E-print Network

    Boyer, Edmond

    EFFECTS OF DIET ON THE MOTILITY OF THE SMALL INTESTINE AND PLASMA INSULIN LEVELS IN SHEEP L. BUENO). Although a post- prandial elevation in plasma immunoreactive insulin (IRI) levels has been described. La teneur plasmatique en glucose et insuline a été évaluée à partir de prélèvements sanguins

  10. Improving Performance in Very Small Firms through Effective Assessment and Feedback

    ERIC Educational Resources Information Center

    Lorenzet, Steven J.; Cook, Ronald G.; Ozeki, Cynthia

    2006-01-01

    Purpose: The purpose of this paper is to improve assessment and feedback processes in the training practices of very small firms, thereby improving the firms' human capital. Design/methodology/approach: The paper reviews research and practice on effective assessment and feedback. Findings: Based on this paper, human resources are increasingly seen…

  11. Small, Rural and Effective: A Study of Secondary Schools. Warwick Papers on Education Policy, No. 1.

    ERIC Educational Resources Information Center

    Tomlinson, J. R. G.; Mortimore, Peter

    Amidst controversy over proposed school closings, Hereford and Worcester (England) local education authorities (LEA) asked for an evaluation of the effectiveness of six small rural "comprehensive" secondary schools (180-450 students) and their importance to surrounding communities. Data were collected on student achievement; teacher and school…

  12. EFFECTS OF WILDFIRE SEVERITY ON SMALL MAMMALS IN NORTHERN ARIZONA PONDEROSA PINE FORESTS

    E-print Network

    cinereicollis), in northern Arizona ponderosa pine (Pinus ponderosa) forests. We examined 2 fire severities, Peromyscus manicu- latus, Pinus ponderosa, ponderosa pine, Spermophilus lateralis, Tamias cinereicollisEFFECTS OF WILDFIRE SEVERITY ON SMALL MAMMALS IN NORTHERN ARIZONA PONDEROSA PINE FORESTS Sean C

  13. Detection of Small Low-Contrast Objects in Mammography: Effect of Viewbox Masking and Luminance

    Microsoft Academic Search

    Jihong Wang; Joel E. Gray

    OBJECTIVE. Viewing conditions can affect an observer's performance in object detection. Our objective was to determine the effect of viewbox masking and luminance on the detection of small low-contrast objects revealed by mammography. MATERIALS AND METHODS. Mammographic contrast-detail images having various film densities were viewed on masked and unmasked viewboxes. Similar images with fixed film con- trast and density were

  14. The effect of randomized cloud seeding on runoff depth from a small watershed in central Israel

    Microsoft Academic Search

    Arie Ben-Zvi; Ala Fanar

    1997-01-01

    The effect of randomized cloud seeding on daily depth of runoff, during 27 years of experiments in central Israel, is estimated through data for a small watershed. The estimation is carried out with respect to depths of precipitation over the watershed and at two control areas. Double ratio and linear regression models are applied for this estimation. Distribution of rainfall

  15. Effective Gene Selection Method With Small Sample Sets Using Gradient-Based and Point Injection Techniques

    Microsoft Academic Search

    D. Huang; Tommy Chow

    2007-01-01

    Microarray gene expression data usually consist of a large amount of genes. Among these genes, only a small fraction is informative for performing cancer diagnostic test. This paper focuses on effective identification of informative genes. We analyze gene selection models from the perspective of optimization theory. As a result, a new strategy is designed to modify conventional search engines. Also,

  16. Ecological effects of small-scale cutting of Philippine mangrove forests

    E-print Network

    Walters, Bradley B.

    Ecological effects of small-scale cutting of Philippine mangrove forests Bradley B. Walters of mangrove forests in the Philippines. Information for the study was obtained through the application of extensive bio-ecological assessments of forests and interviews of forest users. Cut mangrove forests were

  17. Influence of observed diurnal cycles of aerosol optical depth on aerosol direct radiative effect

    NASA Astrophysics Data System (ADS)

    Eck, T. F.; Huttunen, J.; Lehtinen, K. E. J.; Lindfors, A. V.; Myhre, G.; Smirnov, A.; Tripathi, S. N.; Yu, H.

    2013-08-01

    The diurnal variability of aerosol optical depth (AOD) can be significant, depending on location and dominant aerosol type. However, these diurnal cycles have rarely been taken into account in measurement-based estimates of aerosol direct radiative forcing (ADRF) or aerosol direct radiative effect (ADRE). The objective of our study was to estimate the influence of diurnal aerosol variability at the top of the atmosphere ADRE estimates. By including all the possible AERONET sites, we wanted to assess the influence on global ADRE estimates. While focusing also in more detail on some selected sites of strongest impact, our goal was to also see the possible impact regionally. We calculated ADRE with different assumptions about the daily AOD variability: taking the observed daily AOD cycle into account and assuming diurnally constant AOD. Moreover, we estimated the corresponding differences in ADREs, if the single AOD value for the daily mean was taken from the the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra or Aqua overpass times, instead of accounting for the true observed daily variability. The mean impact of diurnal AOD variability on 24 h ADRE estimates, averaged over all AERONET sites, was rather small and it was relatively small even for the cases when AOD was chosen to correspond to the Terra or Aqua overpass time. This was true on average over all AERONET sites, while clearly there can be much stronger impact in individual sites. Examples of some selected sites demonstrated that the strongest observed AOD variability (the strongest morning afternoon contrast) does not typically result in a significant impact on 24 h ADRE. In those cases, the morning and afternoon AOD patterns are opposite and thus the impact on 24 h ADRE, when integrated over all solar zenith angles, is reduced. The most significant effect on daily ADRE was induced by AOD cycles with either maximum or minimum AOD close to local noon. In these cases, the impact on 24 h ADRE was typically around 0.1-0.2 W m-2 (both positive and negative) in absolute values, 5-10% in relative ones.

  18. Effect of small additions of silicon on the amorphization of Zr-Cu-Nb-Fe alloys

    NASA Astrophysics Data System (ADS)

    Arutyunyan, N. A.; Zaitsev, A. I.; Dunaev, S. F.; Fedotova, N. L.

    2015-02-01

    Effect of small additions of silicon on the glass-forming ability and thermal stability of Zr-Cu-Nb-Fe amorphous alloys is studied. It is found that adding 0.5 at % silicon has a positive effect on the alloys' tendency toward amorphization. The possibility of using the region of thermal stability of amorphous alloys as a criterion of glass-forming ability is analyzed.

  19. Review of negative effects of introduced rodents on small mammals on islands

    Microsoft Academic Search

    Donna B. Harris

    2009-01-01

    In this first comprehensive review of negative effects of introduced rodents on insular small mammals, the focal species Rattus rattus, R. norvegicus, R. exulans and Mus musculus are implicated in at least 11 extinctions. Furthermore, removal experiments, eradication campaigns and control programmes\\u000a provide evidence for negative effects on extant populations. While data are currently insufficient for meaningful generalisation\\u000a with regard

  20. Combined effect of YORP and collisions on the rotation rate of small Main Belt asteroids

    NASA Astrophysics Data System (ADS)

    Marzari, F.; Rossi, A.; Scheeres, D. J.

    2011-08-01

    The rotation rate distribution of small Main Belt asteroids is dominated by YORP and collisions. These mechanism act differently depending on the size of the bodies and give rise to non-linear effects when they both operate. Using a Monte Carlo method we model the formation of a steady state population of small asteroids under the influence of both mechanisms and the rotation rate distribution is compared to the observed one as derived from Pravec et al. (Pravec, P. et al. [2008]. Icarus 197, 497-504). A better match to observations is obtained with respect to the case in which only YORP is considered. In particular, an excess of slow rotators is produced in the model with both collisions and YORP because bodies driven to slow rotation by YORP have a random walk-like evolution of the spin induced by repeated collisions with small projectiles. This is a dynamical evolution different from tumbling and it lasts until a large impact takes the body to a faster rotation rate. According to our model, the rotational fission of small asteroids is a very frequent event and might explain objects like P/2010 A2 and its associated tail of millimeter-sized dust particles. The mass loss during fission of small asteroids might significantly influence the overall collisional evolution of the belt. Fission can in fact be considered as an additional erosion mechanism, besides cratering and fragmentation, acting only at small diameters.

  1. Observe how the Coriolis effect influences wind direction

    NSDL National Science Digital Library

    TERC. Center for Earth and Space Science Education

    2003-01-01

    This animated series of satellite images shows Earth science students how the Coriolis effect causes winds in the Northern Hemisphere to veer to the right of their predicted course. Movie controls allow students to repeat, pause, or step through the animation, which can give students more time to analyze the images. Copyright 2005 Eisenhower National Clearinghouse

  2. Effects of entrance crossflow directions to film cooling holes.

    PubMed

    Saumweber, C; Schulz, A; Wittig, S; Gritsch, M

    2001-05-01

    Two-dimensional distributions of local adiabatic film cooling effectiveness as well as discharge coefficients have been measured to investigate the effect of different entrance crossflow orientations and magnitudes on film-cooling performance. Operating conditions have been varied in terms of hot gas Mach number (up to 0.6), coolant crossflow Mach number (up to 0.6), coolant crossflow orientation (perpendicular or parallel with respect to the mainflow), and blowing ratio (0.5-1.5). The temperature ratio of coolant and hot gas was kept constant at 0.56 for the effectiveness tests, leading to an enginelike density ratio of 1.8. Infrared thermography was applied to perform local measurements of the surface temperatures with high resolution. The results indicate that the impact of hot gas crossflow Mach number is not very pronounced within the range of Mach numbers investigated. In contrast to this finding, the effect of internal coolant crossflow is very pronounced and strongly depends on coolant crossflow orientation and the ejected mass flow rate. PMID:11460654

  3. Effectiveness of lethal, directed wolf-depredation control in Minnesota

    USGS Publications Warehouse

    Harper, E.K.; Paul, W.J.; Mech, L.D.; Weisberg, S.

    2008-01-01

    Wolf (Canis lupus) depredations on livestock in Minnesota, USA, are an economic problem for many livestock producers, and depredating wolves are lethally controlled. We sought to determine the effectiveness of lethal control through the analysis of data from 923 government-verified wolf depredations from 1979 to 1998. We analyzed the data by 1) assessing the correlations between the number of wolves killed in response to depredations with number of depredations the following year at state and local levels, and 2) the time to the next depredation. No analysis indicated that trapping wolves substantially reduced the following year's depredations at state or local levels. However, more specific analyses indicated that in certain situations, killing wolves was more effective than no action (i.e., not trapping). For example, trapping and killing adult males decreased the re-depredation risk. At sheep farms, killing wolves was generally effective. Attempting to trap, regardless of the results, seemed more effective at reducing depredations than not trapping, suggesting that mere human activity near depredation sites might deter future depredations.

  4. Acute Stressor Effects on Goal-Directed Action in Rats

    ERIC Educational Resources Information Center

    Braun, Stephanie; Hauber, Wolfgang

    2013-01-01

    Here we examined effects of acute stressors that involve either systemic coadministration of corticosterone/yohimbine (3 mg/kg each) to increase glucocorticoid/noradrenaline activity (denoted as "pharmacological" stressor) or one or several distinct restraint stressors (denoted as "single" vs. "multiple" stressor) on…

  5. Impairment of small airways in COPD patients with frequent exacerbations and effects of treatment with tiotropium

    PubMed Central

    Incorvaia, Cristoforo; Riario-Sforza, Gian Galeazzo; Pravettoni, Chiara; Yacoub, Mona-Rita; Frati, Franco

    2008-01-01

    Disease exacerbations are an important aspect of COPD, because they affect its course and are associated with higher lung function decline. On the other hand, data obtained by biopsies have demonstrated that the progression of COPD is related to an increasing impairment of small airways. We sought to evaluate the small airway impairment (FEF25–75) in two groups of COPD patients (each group had 37 subjects) in relation to the frequency of exacerbations and the effectiveness of treatment with tiotropium bromide on the small airway impairment. The mean number of exacerbations was 3.6/year and 1.38/year in frequent and in infrequent exacerbators, respectively (p < 0.001). The mean value of FEF25–75 at baseline was 624 mL and 865 mL in frequent and in infrequent exacerbators respectively (p = 0.002). The changes in respiratory parameters versus baseline showed increases in mean FEV1, FVC, and FEF25–75 in both groups but only the increase in FEF25–75 in frequent exacerbators was statistically significantly (p = 0.013). During the 3-month period of the study the mean number of exacerbations was 0.66 in frequent and 0.12 in infrequent exacerbators. These findings indicate that COPD patients with frequent exacerbations have a higher impairment of small airways. Treatment with tiotropium in COPD subjects with frequent exacerbations proved to be effective in improving small airway impairment. PMID:18488435

  6. Climate change and wildlife health: direct and indirect effects

    USGS Publications Warehouse

    Hofmeister, Erik; Rogall, Gail Moede; eWsenberg, Kathy; Abbott, Rachel; Work, Thierry; Schuler, Krysten; Sleeman, Jonathan; Winton, James

    2010-01-01

    Climate change will have significant effects on the health of wildlife, domestic animals, and humans, according to scientists. The Intergovernmental Panel on Climate Change projects that unprecedented rates of climate change will result in increasing average global temperatures; rising sea levels; changing global precipitation patterns, including increasing amounts and variability; and increasing midcontinental summer drought (Intergovernmental Panel on Climate Change, 2007). Increasing temperatures, combined with changes in rainfall and humidity, may have significant impacts on wildlife, domestic animal, and human health and diseases. When combined with expanding human populations, these changes could increase demand on limited water resources, lead to more habitat destruction, and provide yet more opportunities for infectious diseases to cross from one species to another. Awareness has been growing in recent years about zoonotic diseases— that is, diseases that are transmissible between animals and humans, such as Lyme disease and West Nile virus. The rise of such diseases results from closer relationships among wildlife, domestic animals, and people, allowing more contact with diseased animals, organisms that carry and transmit a disease from one animal to another (vectors), and people. Disease vectors include insects, such as mosquitoes, and arachnids, such as ticks. Thus, it is impossible to separate the effects of global warming on wildlife from its effects on the health of domestic animals or people. Climate change, habitat destruction and urbanization, the introduction of exotic and invasive species, and pollution—all affect ecosystem and human health. Climate change can also be viewed within the context of other physical and climate cycles, such as the El Niño Southern Oscillation (El Niño), the North Atlantic Oscillation, and cycles in solar radiation that have profound effects on the Earth’s climate. The effects of climate change on wildlife disease are summarized in several areas of scientific study discussed briefly below: geographic range and distribution of wildlife diseases, plant and animal phenology (Walther and others, 2002), and patterns of wildlife disease, community and ecosystem composition, and habitat degradation.

  7. Personality, Problem Drinking, and Drunk Driving: Mediating, Moderating, and Direct-Effect Models

    Microsoft Academic Search

    Alan W. Stacy; Michael D. Newcomb; Peter M. Bentler

    1991-01-01

    Three different general explanations of the effect of personality on problems from drinking alcohol were investigated. One general explanation involved mediating effects. The 2nd explanation involved direct effects of personality. The 3rd general personality process held that alcohol consumption and personality interact as moderating effects on drinking problems. Results provided support for each of the 3 general explanations of personality

  8. The matrix influences direct and indirect effects of an anthropogenic disturbance on marine organisms.

    PubMed

    Mayer-Pinto, Mariana; Underwood, Antony J; Marzinelli, Ezequiel M

    2015-01-01

    The magnitude and direction of direct and indirect effects of disturbances can be context-dependent, with the matrix (surrounding habitat) in which populations are embedded either mitigating or worsening the impacts of disturbances. Chemical disturbances are particularly harmful and can affect organisms directly or indirectly. We used bleach, a common stressor in marine systems, to test hypotheses about direct and indirect effects of anthropogenic disturbances on intertidal grazers and the influence of the surrounding macro-algal matrix on such effects. We manipulated the contaminant, food (biofilm) and surrounding macro-algal matrix. Fewer limpets were found in contaminated areas. Bleach had a strong direct negative effect on limpets and caused a reduction in biofilm food, indirectly affecting limpets. This effect was strongest in the presence of macro-algal matrix. Anthropogenic disturbances can have major consequences via direct and indirect effects on key interacting species. We showed that such effects are, however, context-dependent. Capsule: Pollution is a major driver of biodiversity declines. We show that direct and indirect effects of contaminants on organisms depend on the context in which they occur. PMID:25460615

  9. Effect of hypocholesterolemia on cholesterol synthesis in small intestine of diabetic rats

    SciTech Connect

    Feingold, K.R.; Moser, A.H.

    1987-11-01

    Studies by our and other laboratories have demonstrated that cholesterol synthesis is increased in the small intestine of insulinopenic diabetic animals. In normal animals, many factors have been shown to regulate cholesterol synthesis in the small intestine, including changes in plasma cholesterol levels. The purpose of this study was to determine the effect of lowering plasma cholesterol levels on small intestine cholesterol synthesis in streptozocin-induced diabetic rats. In diabetic rats, 4-aminopyrazolo(3,4-d)pyrimidine (4-APP)-induced hypocholesterolemia (plasma cholesterol levels less than 20 mg/dl) resulted in a 2.5-fold increase in small intestine cholesterol synthesis, which was most marked in the distal small intestine, decreasing proximally. In the distal small intestine the incorporation of /sup 3/H/sub 2/O into cholesterol was 0.28 +/- 0.04 mumol.h-1.g-1 in diabetic rats versus 1.60 +/- 0.38 in diabetic rats administered 4-APP (P less than .01). This stimulation of cholesterol synthesis occurred in the upper villus, middle villus, and crypt cells isolated from the middle intestine of the 4-APP-treated diabetic animals. In agreement with these observations, functional hypocholesterolemia due to Triton WR-1339 administration also stimulated cholesterol synthesis 2.5-fold in the small intestine of normal and diabetic animals. In the distal small intestine, cholesterol synthesis was 0.43 +/- 0.10 mumol.h-1.g-1 in the diabetic rats versus 1.08 +/- 0.21 in diabetic rats treated with Triton WR-1339 (P less than .05). In both the 4-APP and Triton WR-1339 experiments, the response of the diabetic rats was similar to that observed in normal rats.

  10. The effect of sweep direction on avian auditory brainstem responses

    NASA Astrophysics Data System (ADS)

    Brittan-Powell, Elizabeth; Lauer, Amanda; Callahan, Julia; Dooling, Robert; Leek, Marjorie; Gleich, Otto

    2005-04-01

    In mammals, brief rising frequency sweeps result in increased amplitudes for both auditory brainstem response (ABR) and compound action potential (CAP) recordings (Dau, 2000; Shore and Nuttall, 1985). The rising sweep is thought to result in increased synchronous activity. Changing the direction of the sweep exaggerated the delay of processing along the basilar membrane and decreased synchrony of neural responses. Here we recorded ABRs from budgerigars, canaries, and zebra finches to a variety of stimulus parameters, including rising and falling sweeps with different sweep rates, determined by changing duration and frequency range. Both linear and nonlinear sweeps in frequency over time were tested. Results show that rising sweeps produce larger peak amplitudes, shorter latencies and changes in wave morphology such as a narrower wave 1 width than falling sweeps, suggesting greater synchrony of response to sweeps moving from low to high frequency. These data are consistent with mammalian results, but with a different time scale related to temporal characteristics of cochlear stimulation on the short basilar papilla in birds. [Work supported by NIH DC00198, DC001372, DC04664.

  11. Electrocortical effects of directing attention during visual exposure in dentophobia.

    PubMed

    Leutgeb, Verena; Schöngassner, Florian; Schienle, Anne

    2014-08-01

    Fear of pain is a main motivator for avoidance or delay of dental treatment in patients afflicted with dentophobia. Studies employing passive viewing paradigms found motivated attention to the phobic object to be associated with enhanced amplitudes of the late positive potential (LPP). The aim of the current study was to investigate, if explicit attention-guiding instructions are able to modify the LPP. Twenty-three patients suffering from dentophobia and 23 controls were presented with pictures showing disorder-relevant or neutral contents, which were combined with different instructions: to distract the attention away from the picture, to classify the content, or to decide whether the scene elicited fear of pain. Relative to controls, dentophobics displayed enhanced late positivity (300-1000 ms after picture onset) in the fear of pain condition at frontal and central recording sites, whereas there was no group difference during classification and distraction. Within patients, fear of pain elicited greater positivity than classification and distraction. The findings are discussed within the framework of attentional direction. Future studies could investigate whether psychotherapy differentially affects neural correlates of attention regulation. PMID:24837975

  12. Directional and polarimetric effects in the optical domain

    NASA Technical Reports Server (NTRS)

    Vanderbilt, V. C.; Leroy, M.

    1994-01-01

    Papers focused on land surface, atmospheric, and ocean properties are reported. Specific comments pertaining to polarization, models and inversion, and measurements, are given. Recommendations are: continued research into the application potential of the BRDF (Bidirectional Reflectance Distribution Function) and polarization properties of ground surface and atmospheric targets; three dimensional models, which account for the statistical behavior of remotely sensed data, should be extended and inverted in order to support analysis of data potentially covering rolling terrain such that pixels represent heterogeneous mixtures of surface cover types and project ground footprints with sizes between 10 to 6 km, the ground pixel sizes of planned future sensors; available reflectance models should be further validated by means of multi dimensional (directional, spectral, temporal) field data and existing models should be intercompared in more depth to evaluate their performance and limitations; existing methods for model inversion should be validated in more depth in order to quantify the practical limitations and the expected accuracy of the parameters retrieved and new approaches should be developed based upon apriori knowledge of plant canopy development and spectral BRDF properties; there is a need to establish a protocol of validation and intercomparison of the indices and compositing techniques which have been proposed during these last years.

  13. Direct effects of recurrent hypoglycaemia on adrenal catecholamine release.

    PubMed

    Orban, Branly O; Routh, Vanessa H; Levin, Barry E; Berlin, Joshua R

    2015-01-01

    In Type 1 and advanced Type 2 diabetes mellitus, elevation of plasma epinephrine plays a key role in normalizing plasma glucose during hypoglycaemia. However, recurrent hypoglycaemia blunts this elevation of plasma epinephrine. To determine whether recurrent hypoglycaemia affects peripheral components of the sympatho-adrenal system responsible for epinephrine release, male rats were administered subcutaneous insulin daily for 3 days. These recurrent hypoglycaemic animals showed a smaller elevation of plasma epinephrine than saline-injected controls when subjected to insulin-induced hypoglycaemia. Electrical stimulation of an adrenal branch of the splanchnic nerve in recurrent hypoglycaemic animals elicited less release of epinephrine and norepinephrine than in controls, without a change in adrenal catecholamine content. Responsiveness of isolated, perfused adrenal glands to acetylcholine and other acetylcholine receptor agonists was also unchanged. These results indicate that recurrent hypoglycaemia compromised the efficacy with which peripheral neuronal activity stimulates adrenal catecholamine release and demonstrate that peripheral components of the sympatho-adrenal system were directly affected by recurrent hypoglycaemia. PMID:25268022

  14. Mapping small effect mutations in Saccharomyces cerevisiae: impacts of experimental design and mutational properties.

    PubMed

    Duveau, Fabien; Metzger, Brian P H; Gruber, Jonathan D; Mack, Katya; Sood, Natasha; Brooks, Tiffany E; Wittkopp, Patricia J

    2014-07-01

    Genetic variants identified by mapping are biased toward large phenotypic effects because of methodologic challenges for detecting genetic variants with small phenotypic effects. Recently, bulk segregant analysis combined with next-generation sequencing (BSA-seq) was shown to be a powerful and cost-effective way to map small effect variants in natural populations. Here, we examine the power of BSA-seq for efficiently mapping small effect mutations isolated from a mutagenesis screen. Specifically, we determined the impact of segregant population size, intensity of phenotypic selection to collect segregants, number of mitotic generations between meiosis and sequencing, and average sequencing depth on power for mapping mutations with a range of effects on the phenotypic mean and standard deviation as well as relative fitness. We then used BSA-seq to map the mutations responsible for three ethyl methanesulfonate-induced mutant phenotypes in Saccharomyces cerevisiae. These mutants display small quantitative variation in the mean expression of a fluorescent reporter gene (-3%, +7%, and +10%). Using a genetic background with increased meiosis rate, a reliable mating type marker, and fluorescence-activated cell sorting to efficiently score large segregating populations and isolate cells with extreme phenotypes, we successfully mapped and functionally confirmed a single point mutation responsible for the mutant phenotype in all three cases. Our simulations and experimental data show that the effects of a causative site not only on the mean phenotype, but also on its standard deviation and relative fitness should be considered when mapping genetic variants in microorganisms such as yeast that require population growth steps for BSA-seq. PMID:24789747

  15. Aerosol direct effect retrieval over clouds from space-borne passive hyperspectral measurements (Invited)

    NASA Astrophysics Data System (ADS)

    de Graaf, M.; Tilstra, L.; Stammes, P.

    2013-12-01

    A novel approach for the retrieval of the aerosol direct radiative effect (DRE) over clouds will be presented, which is independent of aerosol parameters estimates. The direct effect at the top of the atmosphere (TOA) of aerosols over clouds can be estimated using hyperspectral reflectance measurements from space-borne spectrometers, when the equivalent aerosol-unpolluted cloud scene reflectance spectrum is known. For smoke over clouds the cloud parameters can be estimated from the shortwave infrared (SWIR), where the absorption of the small smoke particles becomes sufficiently small. Using precomputed tables of cloud reflectance spectra, the unpolluted cloud scene spectrum can then be simulated and compared to the real measured polluted cloud scene reflectance spectrum. The UV-radiation absorption by the smoke will lead to a difference between the measured and simulated spectra, which is proportional to the aerosol DRE at TOA. Aerosol microphysical assumptions and retrievals are avoided by modeling only the aerosol-free scene spectra, all the aerosol effects are in the reflectance measurements. The method works especially well for cloud scenes, which can be simulated relatively accurately. An algorithm was developed to derive the aerosol DRE over marine clouds, using the space-borne spectrometer SCIAMACHY, which produced shortwave reflectance spectra (from 240 to 1700 nm contiguously) from 2002 till 2012. These are ideally suited to study the effect of aerosols on the shortwave spectrum. However, since aerosols in general do not have high resolution spectral features, the algorithm can be adapted to suit data from any combination of instruments that measures UV, visible and SWIR reflectances simultaneously. Examples include OMI and MODIS, flying in the A-Train constellation, and TROPOMI, on the future Sentinel 5 precursor mission, combined with NOAA's NPP VIIRS. This would produce aerosol DRE estimates with unprecedented accuracy and spatial resolution. The aerosol DRE was studied over the southeast Atlantic Ocean (seAO), where smoke over clouds occurs during the dry season in southern Africa, one of the major sources for biomass burning aerosols. The smoke is episodically advected away from the continent in a westerly direction to the seAO, where it overlies a semi-permanent stratocumulus deck at altitudes between about 2 - 5 km, absorbing UV radiation. The aerosol DRE over clouds over the seAO averaged through August 2006 was found to be 23 × 8 Wm-2 with a mean variation over the region in this month of 22 Wm-2. Locally the aerosol DRE over clouds in that month was as high as 132 × 8 Wm-2, absorbing about 10% of the local incoming solar radiation. SCIAMACHY measured (black) and simulated aerosol-free cloud spectra for 10 Aug. 2006, 9:13:51 UTC over the southeast Atlantic

  16. Basic steps in establishing effective small group teaching sessions in medical schools

    PubMed Central

    Meo, Sultan Ayoub

    2013-01-01

    Small-group teaching and learning has achieved an admirable position in medical education and has become more popular as a means of encouraging the students in their studies and enhance the process of deep learning. The main characteristics of small group teaching are active involvement of the learners in entire learning cycle and well defined task orientation with achievable specific aims and objectives in a given time period. The essential components in the development of an ideal small group teaching and learning sessions are preliminary considerations at departmental and institutional level including educational strategies, group composition, physical environment, existing resources, diagnosis of the needs, formulation of the objectives and suitable teaching outline. Small group teaching increases the student interest, teamwork ability, retention of knowledge and skills, enhance transfer of concepts to innovative issues, and improve the self-directed learning. It develops self-motivation, investigating the issues, allows the student to test their thinking and higher-order activities. It also facilitates an adult style of learning, acceptance of personal responsibility for own progress. Moreover, it enhances student-faculty and peer-peer interaction, improves communication skills and provides opportunity to share the responsibility and clarify the points of bafflement. PMID:24353692

  17. Basic steps in establishing effective small group teaching sessions in medical schools.

    PubMed

    Meo, Sultan Ayoub

    2013-07-01

    Small-group teaching and learning has achieved an admirable position in medical education and has become more popular as a means of encouraging the students in their studies and enhance the process of deep learning. The main characteristics of small group teaching are active involvement of the learners in entire learning cycle and well defined task orientation with achievable specific aims and objectives in a given time period. The essential components in the development of an ideal small group teaching and learning sessions are preliminary considerations at departmental and institutional level including educational strategies, group composition, physical environment, existing resources, diagnosis of the needs, formulation of the objectives and suitable teaching outline. Small group teaching increases the student interest, teamwork ability, retention of knowledge and skills, enhance transfer of concepts to innovative issues, and improve the self-directed learning. It develops self-motivation, investigating the issues, allows the student to test their thinking and higher-order activities. It also facilitates an adult style of learning, acceptance of personal responsibility for own progress. Moreover, it enhances student-faculty and peer-peer interaction, improves communication skills and provides opportunity to share the responsibility and clarify the points of bafflement. PMID:24353692

  18. How to enhance effectiveness of Direct Attack Judo throws

    E-print Network

    Sacripanti, Attilio

    2014-01-01

    In this paper is performed an appraisal of the Olympic Sport Judo effectiveness in the optics of Biomechanics. To broaden the classical view,the field of experimentation is obviously the high level competition in which most of rotational application can be found applied more or less instinctively by high level Athletes. Considering the two biomechanical tools that are the physical basis of judo throws it is possible to obtain such results from the analysis of high competition application:Lever Techniques are enhanced in their effectiveness in three ways: The rotational movements, strictly connected to the Lever techniques mechanics achieving victory in competition, can be extended to the unbalance phase. The rotational movements can be applied in a totally new way putting away even the unbalance that is basic in the Lever techniques. The Lever tool can be hybridized with the Couple tool to lower the energy consumption. Couple Techniques are enhanced in their effectiveness also in three ways: The Couple tool t...

  19. Effects of transcranial direct current stimulation (tDCS) on human regional cerebral blood flow

    Microsoft Academic Search

    Xin Zheng; David C. Alsop; Gottfried Schlaug

    2011-01-01

    Transcranial direct current stimulation (tDCS) can up- and down-regulate cortical excitability depending on current direction, however our abilities to measure brain-tissue effects of the stimulation and its after-effects have been limited so far. We used regional cerebral blood flow (rCBF), a surrogate measure of brain activity, to examine regional brain-tissue and brain-network effects during and after tDCS. We varied the

  20. Effect of hypokinesia on invertase activity of the mucosa of the small intestine

    NASA Technical Reports Server (NTRS)

    Abdusattarov, A.

    1980-01-01

    The effect of prolonged hypokinesia on the enzyme activity of the middle portion of the small intestine was investigated. Eighty-four mongrel white male rats weighing 170-180 g were divided into two equal groups. The experimental group were maintained in single cages under 30 days of hypokinetic conditions and the control animals were maintained under ordinary laboratory conditions. It is concluded that rates of invertase formation and its inclusion in the composition if the cellular membrane, if judged by the enzyme activity studied in sections of the small intestine, are subject to phase changes in the course of prolonged hypokinesia.

  1. Decadal trends in marine reserves reveal differential rates of change in direct and indirect effects

    USGS Publications Warehouse

    Babcock, R.C.; Shears, N.T.; Alcala, A.C.; Barrett, N.S.; Edgar, G.J.; Lafferty, K.D.; McClanahan, T.R.; Russ, G.R.

    2010-01-01

    Decadal-scale observations of marine reserves suggest that indirect effects on taxa that occur through cascading trophic interactions take longer to develop than direct effects on target species. Combining and analyzing a unique set of long-term time series of ecologic data in and out of fisheries closures from disparate regions, we found that the time to initial detection of direct effects on target species (+ or -SE) was 5.13 + or - 1.9 years, whereas initial detection of indirect effects on other taxa, which were often trait mediated, took significantly longer (13.1 + or - 2.0 years). Most target species showed initial direct effects, but their trajectories over time were highly variable. Many target species continued to increase, some leveled off, and others decreased. Decreases were due to natural fluctuations, fishing impacts from outside reserves, or indirect effects from target species at higher trophic levels. The average duration of stable periods for direct effects was 6.2 + or - 1.2 years, even in studies of more than 15 years. For indirect effects, stable periods averaged 9.1 + or - 1.6 years, although this was not significantly different from direct effects. Populations of directly targeted species were more stable in reserves than in fished areas, suggesting increased ecologic resilience. This is an important benefit of marine reserves with respect to their function as a tool for conservation and restoration.

  2. Direct Evidence for Natural Transmission of Small-Ruminant Lentiviruses of Subtype A4 from Goats to Sheep and Vice Versa

    PubMed Central

    Shah, Cyril; Huder, Jon B.; Böni, Jürg; Schönmann, Marietta; Mühlherr, Janine; Lutz, Hans; Schüpbach, Jörg

    2004-01-01

    Small-ruminant lentiviruses (SRLV), which include the caprine arthritis-encephalitis and the maedi-visna virus, cause persistent inflammatory infections in goats and sheep. SRLV are mainly transmitted from mother to offspring through milk. Transmission after prolonged contact between adult animals has also been observed. The observation that certain SRLV subtypes are found in both goats and sheep suggests that interspecies transmission has occurred on several occasions in the past. We investigated seropositive goats and sheep that were kept together in small mixed herds. Phylogenetic analysis of long proviral sequences in gag and pol, combined with epidemiologic information, demonstrated natural sheep-to-goat transmission of the recently identified SRLV subtype A4 in two instances and goat-to-sheep transmission of the same subtype in one instance. In a further mixed cluster, the direction of the interspecies transmission could not be determined. These findings present for the first time direct evidence that natural interspecies transmission of SRLV is ongoing in both directions. The findings are of relevance to virus eradication programs in both species. PMID:15220425

  3. Future Directions for Cardiovascular Disease Comparative Effectiveness Research

    PubMed Central

    Hlatky, Mark A; Douglas, Pamela S; Cook, Nakela L; Wells, Barbara; Benjamin, Emelia J; Dickersin, Kay; Goff, David C; Hirsch, Alan T; Hylek, Elaine M; Peterson, Eric; Roger, Véronique L; Selby, Joseph V; Udelson, James E; Lauer, Michael S

    2012-01-01

    Comparative effectiveness research (CER) aims to provide decision-makers the evidence needed to evaluate the benefits and harms of alternative clinical management strategies. CER has become a national priority, with considerable new research funding allocated. Cardiovascular disease is a priority area for CER. This workshop report provides an overview of CER methods, with an emphasis on practical clinical trials and observational treatment comparisons. The report also details recommendations to the National Heart Lung and Blood Institute for a new framework for evidence development to foster cardiovascular CER, and specific studies to address eight clinical issues identified by the Institute of Medicine as high priorities for cardiovascular CER. PMID:22796257

  4. Interaction between directional epistasis and average mutational effects

    E-print Network

    Claus O. Wilke; Christoph Adami

    2001-06-28

    We investigate the relationship between the average fitness decay due to single mutations and the strength of epistatic interactions in genetic sequences. We observe that epistatic interactions between mutations are correlated to the average fitness decay, both in RNA secondary structure prediction as well as in digital organisms replicating in silico. This correlation implies that during adaptation, epistasis and average mutational effect cannot be optimized independently. In experiments with RNA sequences evolving on a neutral network, the selective pressure to decrease the mutational load then leads to a reduction of the amount of sequences with strong antagonistic interactions between deleterious mutations in the population.

  5. Aminoguanidine Alleviates Radiation-Induced Small-Bowel Damage Through Its Antioxidant Effect

    SciTech Connect

    Huang, E.-Y. [Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); School of Traditional Chinese Medicine, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Wang, F.-S. [Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Department of Medical Research, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Lin, I-H. [Department of Radiation Oncology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Yang, Kuender D. [Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Department of Medical Research, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China)], E-mail: yangkd@adm.cgmh.org.tw

    2009-05-01

    Purpose: To evaluate the effect and its mechanism of aminoguanidine (AG) on small-bowel protection after whole-abdominal irradiation (WAI) in rats. Methods and Materials: Male Sprague-Dawley rats (300-400 g) subjected to 12 Gy WAI were used for the study. Aminoguanidine at a dose of 50-800 mg/kg was administered by the gavage route 2 h before WAI. Mucosal damage of small bowel was evaluated by the grade of diarrhea and crypt survival; oxidative stress was determined by the level of 8-hydroxy 2'-deoxyguanosine (8-OHdG) with immunohistochemistry (IHC). Nitrosative stress was evaluated by the expression of inducible nitric oxide synthase (iNOS) and 3-nitrotyrosine (3-NT) with IHC, and systemic and portal vein NOx (nitrite + nitrate) levels were measured and compared with and without AG treatment after WAI. Results: Aminoguanidine showed a dose-dependent effect against WAI-induced diarrhea. Aminoguanidine at a dose of 400 mg/kg had the best protective effect, from 92% to 17% (p = 0.002). Aminoguanidine increased crypt survival from 23% to 46% (p = 0.003). It also significantly attenuated 8-OHdG expression but not 3-NT and iNOS expression at both 4 and 8 h after 12-Gy WAI. Aminoguanidine did not alter the portal vein NOx levels 4 and 8 h after 12-Gy WAI. Conclusion: Aminoguanidine has a radioprotective effect against radiation-induced small-bowel damage due to its antioxidant effect but not inhibition of nitric oxide production. Dietary AG may have a potentially protective effect on the small intestine of patients subjected to pelvic and abdominal radiotherapies.

  6. Separation and measurement of direct and indirect effects of light on stomata

    SciTech Connect

    Sharkey, T.D.; Raschke, K.

    1981-07-01

    Conductance for water vapor, assimilation of CO/sub 2/, and intercellular CO/sub 2/ concentration of leaves of five species were determined at various irradiances and ambient CO/sub 2/ concentrations. Conductance and assimilation were then plotted as functions of irradiance and intercellular CO/sub 2/ concentration. On leaves of Xanthium strumarium L., Gossypium hirsutum L., Phaseolus vulgaris L., and Perilla frutescens (L.), Britt., the stomatal response to light was mainly a direct response to light and to a small extent only a response to changes in intercellular CO/sub 2/ concentration. This was also true for stomata of Zea mays L., except at irradiances <150 watts per square meter. Stomata responded to light even in leaves whose net exchange of CO/sub 2/ was reduced to zero. When leaves were inverted and irradiated on the abaxial surface, conductance decreased in the shaded and increased in the illuminated epidermis, indicating that the photoreceptor pigment(s) involved are located in the epidermis. In leaves of X. strumarium, the direct effect of light on conductance is primarily a response to blue light. Stomatal responses to CO/sub 2/ and to light opposed each other. In X. strumarium, stomatal opening in response to light was strongest in CO/sub 2/-free air and saturated at lower irradiances than in CO/sub 2/-containing air. Conversely, stomatal closure in response to CO/sub 2/ was strongest in darkness and it decreased as irradiance increased. In X. strumarium, P. vulgaris, and P. frutescens, an irradiance of 300 watts per square meter was sufficient to eliminate the stomatal response to CO/sub 2/ altogether. Application of abscisic acid, or an increase in vapor pressure deficit, or a decrease in leaf temperature reduced the stomatal conductance at light saturation.

  7. Direct differentiation of hepatic stem-like WB cells into insulin-producing cells using small molecules

    PubMed Central

    Liu, Jianping; Liu, Yanmei; Wang, Honggang; Hao, Haojie; Han, Qingwang; Shen, Jing; Shi, Jun; Li, Chunlin; Mu, Yiming; Han, Weidong

    2013-01-01

    Recent evidence suggests that experimental induction of hepatocytes into pancreatic cells provides new cell transplantation therapy prospects for type 1 diabetes mellitus. Stepwise differentiation from rat liver epithelial stem-like WB-F344 cells (WB cells) into functional insulin-secreting cells will identify key steps in ?-cell development and may yet prove useful for transplantation therapy for diabetic patients. An essential step in this protocol was the generation of pancreatic precursor cell that express Pdx1 based on induction by a combination of 5-aza-2?-deoxycytidine, trichostatin A, retinoic acid, and a mix of insulin, transferrin and selenite. The Pdx1-expressing cells express other pancreatic markers and contribute to endocrine cells in vitro and in vivo. This study indicates an efficient chemical protocol for differentiating WB cells into functional insulin-producing cells using small molecules, and represents a promising hepatocyte-based treatment for diabetes mellitus. PMID:23378917

  8. Comparative effects of avoidance and vaccination in disease spread on a dynamic small-world network

    NASA Astrophysics Data System (ADS)

    Stone, Thomas E.; Jones, Matthew M.; McKay, Susan R.

    2010-12-01

    Dynamic small-world contact networks have fixed short range links and time-varying stochastic long range links. They are used to model mobile populations or as minimal models for traditional small-world networks. Here we study the relative effects of vaccinations and avoidance of infected individuals in a susceptible-infected-recovered (SIR) epidemic model on a dynamic small-world network. We derive the critical mobility required for an outbreak to occur as a function of the disease’s infectivity, recovery rate, avoidance rate, and vaccination rate. We also derive an expression that allows us to calculate the amount of vaccination and/or avoidance necessary to prevent an epidemic. Calculated quantities show excellent agreement with simulations.

  9. A uniform model for direct and converse magnetoelectric effect in laminated composite

    NASA Astrophysics Data System (ADS)

    Zhou, Jian-Ping; Ma, Yuan-Jun; Zhang, Guang-Bin; Chen, Xiao-Ming

    2014-05-01

    Direct and converse magnetoelectric effects are two opposite processes, which were integrated in a model based on equivalent circuit. Following the piezoelectric and magnetostrictive constitutive equations, we obtained magnetic-mechanical-electric equations, and then built a symmetric equivalent circuit about the magnetoelectric coupling. We equivalently analyzed the direct and converse magnetoelectric effects with this equivalent circuit. The numerical calculations fit the reported results very well, including the magnetoelectric changes with the thickness ratio and frequency, the relative lower converse magnetoelectric resonance frequency, and the phase increase of ? around the direct and converse magnetoelectric resonance frequencies. This model helps us understand the magnetoelectric properties deeply, especially for the converse magnetoelectric effect.

  10. The effect of urban street gang densities on small area homicide incidence in a large metropolitan county, 1994-2002.

    PubMed

    Robinson, Paul L; Boscardin, W John; George, Sheba M; Teklehaimanot, Senait; Heslin, Kevin C; Bluthenthal, Ricky N

    2009-07-01

    The presence of street gangs has been hypothesized as influencing overall levels of violence in urban communities through a process of gun-drug diffusion and cross-type homicide. This effect is said to act independently of other known correlates of violence, i.e., neighborhood poverty. To test this hypothesis, we independently assessed the impact of population exposure to local street gang densities on 8-year homicide rates in small areas of Los Angeles County, California. Homicide data from the Los Angeles County Coroners Office were analyzed with original field survey data on street gang locations, while controlling for the established covariates of community homicide rates. Bivariate and multivariate regression analyses explicated strong relationships between homicide rates, gang density, race/ethnicity, and socioeconomic structure. Street gang densities alone had cumulative effects on small area homicide rates. Local gang densities, along with high school dropout rates, high unemployment rates, racial and ethnic concentration, and higher population densities, together explained 90% of the variation in local 8-year homicide rates. Several other commonly considered covariates were insignificant in the model. Urban environments with higher densities of street gangs exhibited higher overall homicide rates, independent of other community covariates of homicide. The unique nature of street gang killings and their greater potential to influence future local rates of violence suggests that more direct public health interventions are needed alongside traditional criminal justice mechanisms to combat urban violence and homicides. PMID:19247837

  11. Direct and contextual effects of individual values on organizational citizenship behavior in teams.

    PubMed

    Arthaud-Day, Marne L; Rode, Joseph C; Turnley, William H

    2012-07-01

    The authors use Schwartz's values theory as an integrative framework for testing the relationship between individual values and peer-reported organizational citizenship behavior (OCB) in teams, controlling for sex, satisfaction, and personality traits. Using hierarchical linear modeling in a sample of 582 students distributed across 135 class project teams, the authors find positive, direct effects for achievement on citizenship behaviors directed toward individuals (OCB-I), for benevolence on citizenship behaviors directed toward the group (OCB-O), and for self-direction on both OCB-I and OCB-O. Applying relational demography techniques to test for contextual effects, the authors find that group mean power scores negatively moderate the relationship between individual power and OCB-I, whereas group mean self-direction scores positively moderate the relationship between self-direction and both OCB-I and OCB-O. PMID:22369271

  12. The direct effects of manipulating body checking in men.

    PubMed

    Walker, D Catherine; Murray, Andrea D; Lavender, Jason M; Anderson, Drew A

    2012-09-01

    The purpose of the current study was to examine how body checking affects men's state body image and state muscle dissatisfaction using an experimental design. Male undergraduates (N=234) were randomly assigned to a high body checking group, in which they were asked to focus their attention on typically disliked body parts, and a low body checking group, in which they were asked to focus on their bodies as a whole and describe themselves using neutral, nonjudgmental terms. Contrary to initial hypotheses, regardless of condition, participants' body image satisfaction decreased significantly following the body checking procedure and did not change significantly after a 10-min delay. Additionally, in both conditions, participants' muscle dissatisfaction did not immediately change, but muscle dissatisfaction increased significantly following the 10-min delay. One mirror exposure session had similar effects on men's body image and muscle dissatisfaction regardless of how they were asked to examine their bodies. PMID:22770996

  13. Effects of Fluid Directions on Heat Exchange in Thermoelectric Generators

    NASA Astrophysics Data System (ADS)

    Suzuki, Ryosuke O.; Sasaki, Yuto; Fujisaka, Takeyuki; Chen, Min

    2012-06-01

    Thermal fluids can transport heat to the large surface of a thermoelectric (TE) panel from hot and/or cold sources. The TE power thus obtainable was precisely evaluated using numerical calculations based on fluid dynamics and heat transfer. The commercial software FLUENT was coupled with a TE model for this purpose. The fluid velocity distribution and the temperature profiles in the fluids and TE modules were calculated in two-dimensional space. The electromotive force was then evaluated for counter-flow and split-flow models to show the effect of a stagnation point. Friction along the fluid surface along a long, flat path was larger than that along a short path split into two parts. The power required to circulate the fluids along the flow path is not negligible and should be considered in TE generation system design.

  14. Simulation model of bi-directional pedestrian considering potential effect ahead and behind

    NASA Astrophysics Data System (ADS)

    Zhang, Qi

    2015-02-01

    This paper presents a simulation model for bi-directional pedestrian behavior. Guide effect and press effect performed by pedestrians with same direction, and contain effect performed by opposite pedestrians were considered as potential effects. Potential field was defined to simulate the complex interactions, which provided an effective and integrated approach to depict the immediate effects imposed by individuals ahead and behind, with different directions. The number of following pedestrians was regarded as a factor for lane change decision. Experiments ran for the model validation and coefficient performance verification. Preventative steering behavior and congestion unlock phenomenon were observed in the simulation. Velocity-density and flow rate-density curves with different coefficients show the effectiveness of the presented model to capture self-organization phenomenon in counter flow. Coefficient performance reveals the flexibility and controllability of the model to apply on various circumstances.

  15. Effect of downed woody debris on small mammal anti-predator behavior.

    SciTech Connect

    Hinkleman, Travis, M.; Orrock, John, L.; Loeb, Susan, C.

    2011-10-01

    Anti-predator behavior can affect prey growth, reproduction, survival, and generate emergent effects in food webs. Small mammals often lower the cost of predation by altering their behavior in response to shrubs,but the importance of other microhabitat features, such as downed woody debris, for anti-predator behavior is unknown. We used givingup densities to quantify the degree to which downed woody debris alters perceived predation risk by small mammals in southeastern pineforests. We placed 14 foraging trays next to large downed woody debris,shrubs, and in open areas for 12 consecutive nights. Moon illumination, a common indicator of predation risk, led to a similar reduction in small mammal foraging in all three microhabitats (open, downed woody debris,and shrub). Small mammals perceived open microhabitats as riskier than shrub microhabitats, with downed woody debris habitats perceived as being of intermediate risk between shrub and open microhabitats. Despite the presumed benefits of the protective cover of downed woody debris, small mammals may perceive downed woody debris as a relatively risky foraging site in southeastern pine forests where the high diversity and abundance of rodent-eating snakes may provide a primary predatory threat.

  16. Observation of Small-scale Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC

    NASA Astrophysics Data System (ADS)

    Abeysekara, A. U.; Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Ayala Solares, H. A.; Barber, A. S.; Baughman, B. M.; Bautista-Elivar, N.; Belmont, E.; BenZvi, S. Y.; Berley, D.; Bonilla Rosales, M.; Braun, J.; Caballero-Mora, K. S.; Carramiñana, A.; Castillo, M.; Cotti, U.; Cotzomi, J.; de la Fuente, E.; De León, C.; DeYoung, T.; Diaz Hernandez, R.; Díaz-Vélez, J. C.; Dingus, B. L.; DuVernois, M. A.; Ellsworth, R. W.; Fiorino, D. W.; Fraija, N.; Galindo, A.; Garfias, F.; González, M. M.; Goodman, J. A.; Gussert, M.; Hampel-Arias, Z.; Harding, J. P.; Hüntemeyer, P.; Hui, C. M.; Imran, A.; Iriarte, A.; Karn, P.; Kieda, D.; Kunde, G. J.; Lara, A.; Lauer, R. J.; Lee, W. H.; Lennarz, D.; León Vargas, H.; Linnemann, J. T.; Longo, M.; Luna-García, R.; Malone, K.; Marinelli, A.; Marinelli, S. S.; Martinez, H.; Martinez, O.; Martínez-Castro, J.; Matthews, J. A. J.; McEnery, J.; Mendoza Torres, E.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Noriega-Papaqui, R.; Oceguera-Becerra, T.; Patricelli, B.; Pelayo, R.; Pérez-Pérez, E. G.; Pretz, J.; Rivière, C.; Rosa-González, D.; Ruiz-Velasco, E.; Ryan, J.; Salazar, H.; Salesa Greus, F.; Sandoval, A.; Schneider, M.; Sinnis, G.; Smith, A. J.; Sparks Woodle, K.; Springer, R. W.; Taboada, I.; Toale, P. A.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Villaseñor, L.; Weisgarber, T.; Westerhoff, S.; Wisher, I. G.; Wood, J.; Yodh, G. B.; Younk, P. W.; Zaborov, D.; Zepeda, A.; Zhou, H.; HAWC Collaboration

    2014-12-01

    The High-Altitude Water Cherenkov (HAWC) Observatory is sensitive to gamma rays and charged cosmic rays at TeV energies. The detector is still under construction, but data acquisition with the partially deployed detector started in 2013. An analysis of the cosmic-ray arrival direction distribution based on 4.9 × 1010 events recorded between 2013 June and 2014 February shows anisotropy at the 10-4 level on angular scales of about 10°. The HAWC cosmic-ray sky map exhibits three regions of significantly enhanced cosmic-ray flux; two of these regions were first reported by the Milagro experiment. A third region coincides with an excess recently reported by the ARGO-YBJ experiment. An angular power spectrum analysis of the sky shows that all terms up to l = 15 contribute significantly to the excesses.

  17. Advanced dynamical models for very well observed asteroids : perturbations from small bodies, relativity, non - gravitational effects.

    NASA Astrophysics Data System (ADS)

    Bernardi, Fabrizio; Farnocchia, Davide; Milani, Andrea

    2012-08-01

    The availability of radar data and high precision optical observations has increased the number of objects with a very well constrained orbit, especially for those objects with a long observed arc. In these cases, the uncertainty of orbital predictions is often dominated by the inaccuracy of the dynamical model. However, the motion of small solar system bodies poses a serious challenge in modeling their dynamics. In particular, for those objects with a chaotic motion small differences in the model are amplified with propagation. Thus, we need to take into account small perturbations too, especially for long - term prediction. An improved dynamical model is relevant in several applications such as assessing the risk of an impact between an asteroid and the Earth. The N - body model describing the motion of a small solar system body includes the Newtonian attraction of the planets. The contribution o f other perturbing bodies has to be taken into account. We propose to include the Moon, two dwarf planets (Ceres and Pluto) and fifteen asteroids (Pallas, Vesta, Juno, Metis, Hygiea, Eunomia, Psyche, Amphitrite, Euphrosyne, Europa, Cybele, Sylvia, Davida, Herculina, Interamnia). The next step is the introduction of the relativity terms due to both the Sun and the planets . Despite their small magnitude, planetary relativistic terms turn out to be relevant for objects experiencing close approaches with a planet. Finally, we discuss non - gravitational effects such as solar radiation pressure and the Yarkovsky effect. In particular, the latter acts as a tiny but secular semimajor axis drift that may decisively drive long - term predictions. These non - gravitational effects are difficult to model as they depend on object ’ s physical properties that are typically unknown. However, a very well observed object can have an orbit precise enough to allow the determination of the parameters defining a non - gravitational perturbation and thus the modeling of the corresponding acceleration.

  18. Pathology-Dependent Effects Linked to Small Heat Shock Proteins Expression: An Update

    PubMed Central

    Arrigo, A.-P.

    2012-01-01

    Small heat shock proteins (small Hsps) are stress-induced molecular chaperones that act as holdases towards polypeptides that have lost their folding in stress conditions or consequently of mutations in their coding sequence. A cellular protection against the deleterious effects mediated by damaged proteins is thus provided to cells. These chaperones are also highly expressed in response to protein conformational and inflammatory diseases and cancer pathologies. Through specific and reversible modifications in their phospho-oligomeric organization, small Hsps can chaperone appropriate client proteins in order to provide cells with resistance to different types of injuries or pathological conditions. By helping cells to better cope with their pathological status, their expression can be either beneficial, such as in diseases characterized by pathological cell degeneration, or deleterious when they are required for tumor cell survival. Moreover, small Hsps are actively released by cells and can act as immunogenic molecules that have dual effects depending on the pathology. The cellular consequences linked to their expression levels and relationships with other Hsps as well as therapeutic strategies are discussed in view of their dynamic structural organization required to interact with specific client polypeptides. PMID:24278676

  19. Effect of different treatment plans on irradiated small-bowel volume in gynecologic patients undergoing whole-pelvic irradiation

    PubMed Central

    Chang, Shih-Chen; Lee, Hsiao-Fei; Ting, Hui-Min; Pan, Tzu-Chao; Liu, Shu-Yu; Chen, Chien-Fu; Wang, Teng-Yi; Juan, Kuo-Jung; Liao, Tsung-I; Huang, Eng-Yen

    2013-01-01

    To evaluate the effect of different treatment plans for whole-pelvic irradiation on small-bowel volumes (SBVs) in patients with gynecologic malignancies, 40 patients were enrolled in this study. Computed tomography (CT) simulations were performed, and the small bowel of each patient was outlined manually. Treatment plans with equal-weighted (EW) and non-equal-weighted (NEW) (70% in bilateral directions) techniques of four-field and intensity-modulated radiation therapy (IMRT) were performed. The V10–V100 represented the volume (cm3) at different levels of the prescribed doses (10–100%). The V10–V100 was compared among the different treatment planning techniques, and patients who were suitable for IMRT or NEW were identified. IMRT and NEW significantly reduced the V50–V100 and V40–V60 levels compared with EW, respectively. NEW caused a significant reduction in the V30–V60 levels in patients with a BMI ?26 kg/m2. Patients with IMRT demonstrated lower V70–V100 levels compared with those with NEW. In patients with a BMI ?26 kg/m2 or an age ?55 years, lower V20–V50 levels were noted using NEW compared with IMRT. Treatment planning with larger weighting in the bilateral directions in four-field radiotherapy reduces the low-dose SBV in patients with gynecologic malignancies, especially in those with a high BMI or the elderly. IMRT effectively reduces high-dose SBV, especially in patients with a low BMI. PMID:23536544

  20. Investigations of surface-tension effects due to small-scale complex boundaries

    NASA Astrophysics Data System (ADS)

    Feng, Jiansheng

    In this Ph.D. dissertation, we have investigated some important surface-tension phenomena including capillarity, wetting, and wicking. We mainly focus on the geometric aspects of these problems, and to learn about how structures affect properties. . In the first project (Chapter 2), we used numerical simulations and experiments to study the meniscus of a fluid confined in capillaries with complicated cross-sectional geometries. In the simulations, we computed the three-dimensional shapes of the menisci formed in polygonal and star-shaped capillaries with sharp or rounded corners. Height variations across the menisci were used to quantify the effect of surface tension. Analytical solutions were derived for all the cases where the cross-sectional geometry was a regular polygon or a regular star-shape. Power indices that characterize the effects of corner rounding were extracted from simulation results. These findings can serve as guide for fabrications of unconventional three-dimensional structures in Capillary Force Lithography experiments. Experimental demonstrations of the working principle was also performed. Although quantitative matching between simulation and experimental results was not achieved due to the limitation of material properties, clear qualitative trends were observed and interesting three-dimensional nano-structures were produced. A second project (Chapter 3) focused on developing techniques to produce three-dimensional hierarchically structured superhydrophobic surfaces with high aspect ratios. We experimented with two different high-throughput electron-beam-lithography processes featuring single and dual electron-beam exposures. After a surface modification procedure with a hydrophobic silane, the structured surfaces exhibited two distinct superhydrophobic behaviors---high and low adhesion. While both types of superhydrophobic surfaces exhibited very high (approximately 160° water advancing contact angles, the water receding contact angles on these two different types of surfaces differed by about 50° ˜ 60°, with the low-adhesion surfaces at about 120° ˜ 130° and the high-adhesion surfaces at about 70° ˜ 80°. Characterizations of both the microscopic structures and macroscopic wetting properties of these product surfaces allowed us to pinpoint the structural features responsible for specific wetting properties. It is found that the advancing contact angle was mainly determined by the primary structures while the receding contact angle is largely affected by the side-wall slope of the secondary features. This study established a platform for further exploration of the structure aspects of surface wettability. In the third and final project (Chapter 4), we demonstrated a new type of microfluidic channel that enable asymmetric wicking of wetting fluids based on structure-induced direction-dependent surface-tension effect. By decorating the side-walls of open microfluidic channels with tilted fins, we were able to experimentally demonstrate preferential wicking behaviors of various IPA-water mixtures with a range of contact angles in these channels. A simplified 2D model was established to explain the wicking asymmetry, and a complete 3D model was developed to provide more accurate quantitative predictions. The design principles developed in this study provide an additional scheme for controlling the spreading of fluids. The research presented in this dissertation spreads out across a wide range of physical phenomena (wicking, wetting, and capillarity), and involves a number of computational and experimental techniques, yet all of these projects are intrinsically united under a common theme: we want to better understand how simple fluids respond to small-scale complex surface structures as manifestations of surface-tension effects. We hope our findings can serve as building blocks for a larger scale endeavor of scientific research and engineering development. After all, the pursue of knowledge is most meaningful if the results improve the well-being of the society and the advancement of humanity

  1. Measurement of rainfall distribution on a small catchment for the evaluation of canopy interception effects

    NASA Astrophysics Data System (ADS)

    Maurer, Thomas; Schapp, Andrea; Büchner, Steffen; Menzel, Hannes; Hinz, Christoph

    2014-05-01

    Variability of rainfall and throughfall is an essential characteristic of the water balance at spatial scales ranging from meters to hundreds of meters or even kilometers. The amount of throughfall is governed by the characteristics of the vegetation canopy and the involved interception and stemflow effects. In initial, developing ecosystems, distinct patterns of the growing vegetation (e.g. patchiness) supposedly govern the spatial distribution of water in the system, thereby initiating and supporting hydro-ecological feedback processes. Questions are i) is the spatial variability of vegetation relevant for the system as a whole, and ii) how does the distribution of the effective precipitation (i.e. the infiltration) change over time in dependency of vegetation succession? We present the first results of a spatially distributed measurement approach of surface-near precipitation on the constructed catchment "Hühnerwasser" ("Chicken Creek"). The 6-ha site is located in the recultivation area of the lignite open-cast mine "Welzow-Süd" in Lower Lusatia, Brandenburg, Germany. Here, the free development of an initial ecosystem is investigated since September 2005. After eight years of succession, the spatial distribution of plant species is highly heterogeneous, and gains increasing influence on throughfall patterns, thus impacting the distribution of soil humidity and possibly even surface runoff. For spatially distributed precipitation measurement, 47 tipping bucket rain gauges were installed in heights of 0.5 m and 1.0 m along two transects on the catchment. Rain gauge data were collected by a wireless sensor node network provided by the Sens4U joint research project. The transects run NW-SE and NE-SW and cover the range of plant communities presently existing in the ecosystem: locust copses, dense sallow thorn bushes and reeds, base herbaceous and medium-rise small-reed vegetation, and open areas covered by moss and lichens. The raw measurement data were temporally aggregated using a VBA script in order to characterize interception for various types of precipitation events on different time scales. First results from the measurement period 17th July - 3rd September 2013 widely exhibit a good accordance with reference data from on-site weather stations for sites on open ground, while canopy sites show more heterogeneous values, either due to interception or due to canopy collection effects. However, it was found that the explanation of the differences between comparable sites requires an additional inclusion of other relevant parameters, e.g. wind speed and direction, screening effects, and specific canopy characteristics. Moreover, extreme precipitation events sometimes seemed to lead to incorrect measurements either by the sensor and / or node, which required supplementary quality controls of equipment and data. Results from future long-term measurements on the "Hühnerwasser" catchment will be used to identify possible plant-soil feedback mechanisms and to parameterize models that simulate the behavior of initial eco-hydrological systems.

  2. Directly Mapping Magnetic Field Effects of Neuronal Activity by Magnetic Resonance

    E-print Network

    Gabrieli, John

    Directly Mapping Magnetic Field Effects of Neuronal Activity by Magnetic Resonance Imaging Jinhu Center at San Antonio, San Antonio, Texas Abstract: Magnetic resonance imaging (MRI) of brain functional functional activity by directly detecting magnetic fields induced by neuronal firing. Using a well

  3. Effects of Foreign Direct Investment and Human capital formation on labour markets in India

    E-print Network

    Bandyopadhyay, Antar

    Effects of Foreign Direct Investment and Human capital formation on labour markets in India Gunja@gmail.com +91-7890059582 #12;Abstract Foreign Direct Investment (FDI) and human capital formation's interaction between FDI and human capital raises wage inequality, though human capital itself is negatively associated

  4. The Effects of Directionality Training on Reversals in Reading and Writing.

    ERIC Educational Resources Information Center

    Steen, Marcia; Jansson, Deborah

    The effectiveness of directionality training in alleviating a tendency to reverse letters and/or words was tested with 24 children (ages 8-9 years) with reading and math problems, who had such tendencies. The strategies used to teach directionality were based upon strategies used in previous studies with younger children that resulted in a…

  5. Effects of Direct and Indirect Instruction on Fostering Decision-Making Competence in Socioscientific Issues

    ERIC Educational Resources Information Center

    Bottcher, Florian; Meisert, Anke

    2013-01-01

    In this study the effects of different learning environments on the promotion of decision-making competence for the socioscientific issue of genetically modified crops is investigated. The comparison focuses on direct vs. indirect instructions. Therefore on the one hand a sophisticated decision-making strategy was presented to the directly

  6. Compensation for the effects of mutual coupling on direct data domain adaptive algorithms

    Microsoft Academic Search

    Raviraj S. Adve; Tapan Kumar Sarkar

    2000-01-01

    This paper investigates the effects of mutual coupling between the elements of an array on direct data domain algorithms. Mutual coupling severely undermines the interference suppression capabilities of direct data domain algorithms. The method of moments (MoM) is used to evaluate the mutual coupling between the elements of a given array. The MoM admittance matrix is then used to eliminate

  7. The Effects of Direct Training and Treatment Integrity on Treatment Outcomes in School Consultation.

    ERIC Educational Resources Information Center

    Sterling-Turner, Heather E.; Watson, T. Steuart; Moore, James W.

    2002-01-01

    Study attempts to expand the empirical consultation research base by examining the effects of direct and indirect consultee training methods on treatment integrity and treatment outcomes. A multiple baseline design across consultation dyads was used to investigate the influence of these variables. Results suggest that direct consultee training led…

  8. EFFECT OF DIRECTIONAL SWITCHING FREQUENCY ON TOLUENE DEGRADATION IN A VAPOR-PHASE BIOREACTOR. (R826168)

    EPA Science Inventory

    A potential method to improve biomass distribution and the stability of vapor-phase bioreactors is to operate them in a directionally switching mode such that the contaminant air stream direction is periodically reversed through the reactor. In this study, the effect of switching...

  9. Direct and Contextual Effects of Individual Values on Organizational Citizenship Behavior in Teams

    Microsoft Academic Search

    Marne L. Arthaud-Day; Joseph C. Rode; William H. Turnley

    2012-01-01

    The authors use Schwartz's values theory as an integrative framework for testing the relationship between individual values and peer-reported organizational citizenship behavior (OCB) in teams, controlling for sex, satisfaction, and personality traits. Using hierarchical linear modeling in a sample of 582 students distributed across 135 class project teams, the authors find positive, direct effects for achievement on citizenship behaviors directed

  10. Effects of Direct Instruction and Metacomprehension Training on Finding Main Ideas.

    ERIC Educational Resources Information Center

    Graves, Anne W.

    1986-01-01

    Twenty-four learning disabled children (grades 5-8) with adequate decoding skills, but who demonstrated problems in reading comprehension, received training in finding the main idea. Among several findings was that metacomprehension (self-monitoring) plus direct instruction was more effective than direct instruction alone. (Author/JW)

  11. Effects of uncertain geoacoustic parameters and coastal shipping densities on shipping noise directionality

    Microsoft Academic Search

    Thomas J. Hayward; Richard M. Heitmeyer

    2005-01-01

    The bearing-elevation directionality of low-frequency shipping noise is influenced both by the sediment geoacoustic parameters and by the coastal shipping density. This study examines the effects of geoacoustic parameter and shipping density uncertainties on noise directionality through simulations for a North Pacific site. The simulations are based in part on stochastic models of the spatial variations of geoacoustic parameters that

  12. An empirical study of direct rebound effect for passenger transport in urban China

    Microsoft Academic Search

    H. Wang; P. Zhou; D. Q. Zhou

    2012-01-01

    Transport sector accounts for about 8% of total energy consumption in China and this share will likely increase in the visible future. Improving energy efficiency has been considered as a major way for reducing transport energy use, whereas its effectiveness might be affected by the rebound effect. This paper estimates the direct rebound effect for passenger transport in urban China

  13. Academic Libraries: The Dimensions of Their Effectiveness. New Directions in Information Management, Number 32.

    ERIC Educational Resources Information Center

    McDonald, Joseph A.; Micikas, Lynda Basney

    Librarians have not been able to agree on a meaning for library effectiveness that is both comprehensive and practical, expressed in terms that suggest directions for improvement. This book applies Kim Cameron's principles of organization effectiveness to the traditional issues of academic library effectiveness. The investigation described is…

  14. Non-contact small animal fluorescence imaging system for simultaneous multi-directional angular-dependent data acquisition

    PubMed Central

    Lee, Jong Hwan; Kim, Hyun Keol; Chandhanayingyong, Chandhanarat; Lee, Francis Young-In; Hielscher, Andreas H.

    2014-01-01

    We present a novel non-contact small animal fluorescent molecular tomography (FMT) imaging system. At the heart of the system is a new mirror-based imaging head that was designed to provide 360-degree measurement data from an entire animal surface in one step. This imaging head consists of two conical mirrors, which considerably reduce multiple back reflections between the animal and mirror surfaces. These back reflections are common in existing mirror-based imaging heads and tend to degrade the quality of raw measurement data. In addition, the introduction of a novel ray-transfer operator allows for the inclusion of the angular dependent data in the image reconstruction process, which results in higher image resolution. We describe in detail the system design and implementation of the hardware components as well as the transport-theory-based image reconstruction algorithm. Using numerical simulations, measurements on a well-defined phantom and a live animal, we evaluate the system performance and show the advantages of our approach. PMID:25071965

  15. Non-contact small animal fluorescence imaging system for simultaneous multi-directional angular-dependent data acquisition.

    PubMed

    Lee, Jong Hwan; Kim, Hyun Keol; Chandhanayingyong, Chandhanarat; Lee, Francis Young-In; Hielscher, Andreas H

    2014-07-01

    We present a novel non-contact small animal fluorescent molecular tomography (FMT) imaging system. At the heart of the system is a new mirror-based imaging head that was designed to provide 360-degree measurement data from an entire animal surface in one step. This imaging head consists of two conical mirrors, which considerably reduce multiple back reflections between the animal and mirror surfaces. These back reflections are common in existing mirror-based imaging heads and tend to degrade the quality of raw measurement data. In addition, the introduction of a novel ray-transfer operator allows for the inclusion of the angular dependent data in the image reconstruction process, which results in higher image resolution. We describe in detail the system design and implementation of the hardware components as well as the transport-theory-based image reconstruction algorithm. Using numerical simulations, measurements on a well-defined phantom and a live animal, we evaluate the system performance and show the advantages of our approach. PMID:25071965

  16. The effects of land use change and precipitation change on direct runoff in Wei River watershed, China.

    PubMed

    Dong, Leihua; Xiong, Lihua; Lall, Upmanu; Wang, Jiwu

    2015-01-01

    The principles and degrees to which land use change and climate change affect direct runoff generation are distinctive. In this paper, based on the MODIS data of land use in 1992 and 2003, the impacts of land use and climate change are explored using the Soil Conservation Service Curve Number (SCS-CN) method under two defined scenarios. In the first scenario, the precipitation is assumed to be constant, and thus the consequence of land use change could be evaluated. In the second scenario, the condition of land use is assumed to be constant, so the influence only induced by climate change could be assessed. Combining the conclusions of two scenarios, the effects of land use and climate change on direct runoff volume can be separated. At last, it is concluded: for the study basin, the land use types which have the greatest effect on direct runoff generation are agricultural land and water body. For the big sub basins, the effect of land use change is generally larger than that of climate change; for middle and small sub basins, most of them suffer more from land use change than from climate change. PMID:25633954

  17. Direct investment by stepfathers can mitigate effects on educational outcomes but does not improve behavioural difficulties

    PubMed Central

    Emmott, Emily H.; Mace, Ruth

    2014-01-01

    In contemporary developed populations, stepfather presence has been associated with detrimental effects on child development. However, the proximate mechanisms behind such effects are yet to be fully explored. From a behavioural ecological perspective, the negative effects associated with stepfathers may be due to the reduced quantity and quality of investments children receive within stepfather households. Here, we build on previous studies by investigating whether the effects of stepfather presence on child outcomes are driven by differences in maternal and partner (i.e., father or stepfather) direct investments. We use data from the Avon Longitudinal Study of Parents and Children to explore stepfather effects on children’s educational achievement and behavioural difficulties at age 7. Our results indicate that, for educational achievement, stepfather effects are due to the lower levels of direct investments children receive. For behavioural difficulty, stepfather effects are due to multiple factors whereby stepfather presence is associated with greater difficulties independent of investment levels, and direct investments from stepfathers are ineffective. Our results suggest that the negative effects of stepfathers on child outcomes can be explained, in part, by the reduced quantity and the ineffectiveness of direct investments children receive from stepfathers. Furthermore, the effects of stepfather direct investments seem to vary between child outcomes. PMID:25214758

  18. COMMUNITY ECOLOGY -ORIGINAL RESEARCH Direct versus indirect effects of habitat fragmentation

    E-print Network

    With, Kimberly A.

    richness than interior cells. Frag- mentation per se did not have a direct effect on local-scale diversity patches. Thus, although frag- mentation typically entails habitat loss, habitat loss can occur in ways

  19. Modeling the Direct and Indirect Effects of Atmospheric Aerosols on Tropical Cyclones

    E-print Network

    Lee, Keun-Hee

    2012-02-14

    The direct and indirect effects of aerosols on the hurricane ‘Katrina’ have been investigated using the WRF model with a two-moment bulk microphysical scheme and modified Goddard shortwave radiation scheme. Simulations of the hurricane ‘Katrina...

  20. Effects of temperature on pacemaker potentials in the mouse small intestine

    Microsoft Academic Search

    Yoshihiko Kito; Hikaru Suzuki

    2007-01-01

    The effects of temperature on the generation of pacemaker potentials recorded from myenteric interstitial cells of Cajal (ICC-MY)\\u000a distributed in the mouse small intestine were investigated using intracellular recording techniques. In response to increasing\\u000a temperatures in the range of 26–40C, the frequency and maximum rate of rise (dV\\/dt\\u000a max) of pacemaker potentials were increased while their duration was decreased. The

  1. Solvent additive effects on small molecule crystallization in bulk heterojunction solar cells probed during spin casting.

    PubMed

    Perez, Louis A; Chou, Kang Wei; Love, John A; van der Poll, Thomas S; Smilgies, Detlef-M; Nguyen, Thuc-Quyen; Kramer, Edward J; Amassian, Aram; Bazan, Guillermo C

    2013-11-26

    Solvent additive processing can lead to drastic improvements in the power conversion efficiency (PCE) in solution processable small molecule (SPSM) bulk heterojunction solar cells. In situ grazing incidence wide-angle X-ray scattering is used to investigate the kinetics of crystallite formation during and shortly after spin casting. The additive is shown to have a complex effect on structural evolution invoking polymorphism and enhanced crystalline quality of the donor SPSM. PMID:24002890

  2. A site-directed Staphylococcus aureus hemB mutant is a small-colony variant which persists intracellularly.

    PubMed Central

    von Eiff, C; Heilmann, C; Proctor, R A; Woltz, C; Peters, G; Götz, F

    1997-01-01

    Although small-colony variants (SCVs) of Staphylococcus aureus have been recognized for many years, this phenotype has only recently been related to persistent and recurrent infections. Clinical S. aureus SCVs are frequently auxotrophic for menadione or hemin, two compounds involved in the biosynthesis of the electron transport chain elements menaquinone and cytochromes, respectively. While this observation as well as other biochemical characteristics of SCVs suggests a link between electron-transport-defective strains and persistent infections, the strains examined thus far have been genetically undefined SCVs. Therefore, we generated a stable mutant in electron transport by interrupting one of the hemin biosynthetic genes, hemB, in S. aureus by inserting an ermB cassette into hemB. We isolated a hemB mutant, due to homologous recombination, by growth at a nonpermissive temperature and selection for erythromycin resistance. This mutant showed typical characteristics of clinical SCVs, such as slow growth, decreased pigment formation, low coagulase activity, reduced hemolytic activity, and resistance to aminoglycosides. Additionally, the mutant was able to persist within cultured endothelial cells due to decreased alpha-toxin production. Northern and Western blot analyses showed that expression of alpha-toxin and that of protein A were markedly reduced, at both the mRNA and the protein level. The SCV phenotype of the hemB mutant was reversed by growth with hemin or by complementation with intact hemB. Hence, a defect in the electron transport system allows S. aureus SCVs to resist aminoglycosides and persist intracellularly. PMID:9244256

  3. Noise directivity and group velocity tomography in a region with small velocity contrasts: the northern Baltic shield

    NASA Astrophysics Data System (ADS)

    Poli, P.; Pedersen, H. A.; Campillo; , M.; Polenet/Lapnet Working Group

    2013-01-01

    Ambient noise tomography (ANT) is widely used to image strong velocity variations within the upper crust. Using careful processing, we obtained a 3-D model of shear velocities in the upper crust beneath northern Finland, where the lateral velocity variations are less than 3 per cent. As part of the tomography, the noise field is analysed. It is strongly heterogeneous but the signal-to-noise ratio is sufficient to obtain stable dispersion curves for all profile azimuths. Our results show that the directions of dominant noise sources of Rayleigh and Love waves are the same, but the amplitude distribution with azimuth is different for the two types of waves. More intriguingly, the high frequency Love waves are dominated by a mixture of higher modes rather than the fundamental mode. The reconstructed 3-D model shows the Lapland Granulite Belt as a high velocity body with a limit at surface in excellent agreement with geological observations at surface. Following this interface at depth, our results are compatible with previous studies suggesting an Archean north oriented subduction.

  4. Estimation of direct additive, maternal additive, heterotic and maternal heterotic effects from crossbreeding goats in Kenya

    E-print Network

    Ahuya, Camillus Osundo

    1987-01-01

    ESTIMATION OF DIRECT ADDITIVE, MATERNAL ADDITIVE, HETEROTIC AND MATERNAL HETEROTIC EFFECTS FROM CROSSBREEDING GOATS IN KENYA A Thesis by CAMILLIJS OSUNDO AJJJJYA Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 1987 t'Jajor Subject: Animal Breeding ESTIMATION OF DIRECT ADDITIVE, MATERNAL ADDITIVE, HETEROTIC AND MATERNAL HETEROTIC EFFECTS FROM CROSSBREEDING GOATS IN KENYA A Thesis CAMILLUS OSUNDO AHUYA...

  5. Firm-specific Effects on Location Decisions of Foreign Direct Investment in China's Logistics Industry

    Microsoft Academic Search

    Junjie Hong

    2007-01-01

    Hong J. (2007) Firm-specific effects on location decisions of foreign direct investment in China's logistics industry, Regional Studies41, 673–683. This paper uses conditional logit models to investigate firms-specific effects on location decisions of foreign direct investment in China's logistics industry. Based on a recent census database, the empirical results indicate that the importance of some location factors varies with firm

  6. The effect of small-wave modulation on the electromagnetic bias

    NASA Technical Reports Server (NTRS)

    Rodriguez, Ernesto; Kim, Yunjin; Martin, Jan M.

    1992-01-01

    The effect of the modulation of small ocean waves by large waves on the physical mechanism of the EM bias is examined by conducting a numerical scattering experiment which does not assume the applicability of geometric optics. The modulation effect of the large waves on the small waves is modeled using the principle of conservation of wave action and includes the modulation of gravity-capillary waves. The frequency dependence and magnitude of the EM bias is examined for a simplified ocean spectral model as a function of wind speed. These calculations make it possible to assess the validity of previous assumptions made in the theory of the EM bias, with respect to both scattering and hydrodynamic effects. It is found that the geometric optics approximation is inadequate for predictions of the EM bias at typical radar altimeter frequencies, while the improved scattering calculations provide a frequency dependence of the EM bias which is in qualitative agreement with observation. For typical wind speeds, the EM bias contribution due to small-wave modulation is of the same order as that due to modulation by the nonlinearities of the large-scale waves.

  7. From hot hands to declining effects: the risks of small numbers.

    PubMed

    Lauer, Michael S

    2012-07-01

    About 25 years ago, a group of researchers demonstrated that there is no such thing as the "hot hand" in professional basketball. When a player hits 5 or 7 shots in a row (or misses 10 in a row), what's at work is random variation, nothing more. However, random causes do not stop players, coaches, fans, and media from talking about and acting on "hot hands," telling stories and making choices that ultimately are based on randomness. The same phenomenon is true in medicine. Some clinical trials with small numbers of events yielded positive findings, which in turn led clinicians, academics, and government officials to talk, telling stories and sometimes making choices that were later shown to be based on randomness. I provide some cardiovascular examples, such as the use of angiotensin receptor blockers for chronic heart failure, nesiritide for acute heart failure, and cytochrome P-450 (CYP) 2C19 genotyping for the acute coronary syndromes. I also review the more general "decline effect," by which drugs appear to yield a lower effect size over time. The decline effect is due at least in part to over interpretation of small studies, which are more likely to be noticed because of publication bias. As funders of research, we at the National Heart, Lung, and Blood Institute seek to support projects that will yield robust, credible evidence that will affect practice and policy in the right way. We must be alert to the risks of small numbers. PMID:22742403

  8. The role of effective discharge in the ocean delivery of particulate organic carbon by small, mountainous river systems

    USGS Publications Warehouse

    Wheatcroft, R.A.; Goni, M.A.; Hatten, J.A.; Pasternack, G.B.; Warrick, J.A.

    2010-01-01

    Recent research has shown that small, mountainous river systems (SMRS) account for a significant fraction of the global flux of sediment and particulate organic carbon (POC) to the ocean. The enormous number of SMRS precludes intensive studies of the sort conducted on large systems, necessitating development of a conceptual framework that permits cross-system comparison and scaling up. Herein, we introduce the geomorphic concept of effective discharge to the problem of source-to-sink POC transport. This idea recognizes that transport effectiveness is the product of discharge frequency and magnitude, wherein the latter is quantified as a power-law relationship between discharge and load (the 'rating curve'). An analytical solution for effective discharge (Qe) identifies two key variables: the standard deviation of the natural logarithm of discharge (??q), and the rating exponent of constituent i (bi Data from selected SMRS are used to show that for a given river Qe-POC < Qesediment, Qe for different POC constituents (e.g., POCfossil vs. POC(modern) differs in predictable ways, and Qe for a particular constituent can vary seasonally. When coupled with the idea that discharge peaks of small rivers may be coincident with specific oceanic conditions (e.g., large waves, wind from a certain direction) that determine dispersal and burial, these findings have potentially important implications for POC fate on continental margins. Future studies of POC transport in SMRS should exploit the conceptual framework provided herein and seek to identify how constituent-specific effective discharges vary between rivers and respond to perturbations. ?? 2010, by the American Society of Limnology and Oceanography, Inc.

  9. [Comparison of cost-effectiveness between urimem and direct freezing for urinary protein preservation].

    PubMed

    Wang, Mingming; Liu, Xuejiao; Jia, Lulu; Sun, Ying; Gao, Youhe; Li, Mingxi

    2014-07-01

    To compare two enrichment and preservation methods of urinary proteins, stored in polyvinylidene difluoride (PVDF) membrane (Urimem) or direct freezing, we examined the differences between the two methods in time, space, costs of supplies and electricity, degree of protein degradation and convenience of the sample handling. The urimem method is superior in the storage space, the cost of electricity and the clinical convenience compared to the direct freezing method. However, the direct freezing method is superior in the time and the cost of supplies to the urimem method. The enrichment and preservation of urinary proteins using urimem have more cost-effective benefits compared to those of the direct freezing method. PMID:25345013

  10. Temperature effect on the small-to-large crossover lengthscale of hydrophobic hydration

    SciTech Connect

    Djikaev, Y. S., E-mail: idjikaev@buffalo.edu; Ruckenstein, E. [Department of Chemical and Biological Engineering, SUNY at Buffalo, Buffalo, New York 14260 (United States)] [Department of Chemical and Biological Engineering, SUNY at Buffalo, Buffalo, New York 14260 (United States)

    2013-11-14

    The thermodynamics of hydration is expected to change gradually from entropic for small solutes to enthalpic for large ones. The small-to-large crossover lengthscale of hydrophobic hydration depends on the thermodynamic conditions of the solvent such as temperature, pressure, presence of additives, etc. We attempt to shed some light on the temperature dependence of the crossover lengthscale by using a probabilistic approach to water hydrogen bonding that allows one to obtain an analytic expression for the number of bonds per water molecule as a function of both its distance to a solute and solute radius. Incorporating that approach into the density functional theory, one can examine the solute size effects on its hydration over the entire small-to-large lengthscale range at a series of different temperatures. Knowing the dependence of the hydration free energy on the temperature and solute size, one can also obtain its enthalpic and entropic contributions as functions of both temperature and solute size. These functions can provide some interesting insight into the temperature dependence of the crossover lengthscale of hydrophobic hydration. The model was applied to the hydration of spherical particles of various radii in water in the temperature range from T = 293.15 K to T = 333.15 K. The model predictions for the temperature dependence of the hydration free energy of small hydrophobes are consistent with the experimental and simulational data on the hydration of simple molecular solutes. Three alternative definitions for the small-to-large crossover length-scale of hydrophobic hydration are proposed, and their temperature dependence is obtained. Depending on the definition and temperature, the small-to-large crossover in the hydration mechanism is predicted to occur for hydrophobes of radii from one to several nanometers. Independent of its definition, the crossover length-scale is predicted to decrease with increasing temperature.

  11. Temperature effect on the small-to-large crossover lengthscale of hydrophobic hydration

    NASA Astrophysics Data System (ADS)

    Djikaev, Y. S.; Ruckenstein, E.

    2013-11-01

    The thermodynamics of hydration is expected to change gradually from entropic for small solutes to enthalpic for large ones. The small-to-large crossover lengthscale of hydrophobic hydration depends on the thermodynamic conditions of the solvent such as temperature, pressure, presence of additives, etc. We attempt to shed some light on the temperature dependence of the crossover lengthscale by using a probabilistic approach to water hydrogen bonding that allows one to obtain an analytic expression for the number of bonds per water molecule as a function of both its distance to a solute and solute radius. Incorporating that approach into the density functional theory, one can examine the solute size effects on its hydration over the entire small-to-large lengthscale range at a series of different temperatures. Knowing the dependence of the hydration free energy on the temperature and solute size, one can also obtain its enthalpic and entropic contributions as functions of both temperature and solute size. These functions can provide some interesting insight into the temperature dependence of the crossover lengthscale of hydrophobic hydration. The model was applied to the hydration of spherical particles of various radii in water in the temperature range from T = 293.15 K to T = 333.15 K. The model predictions for the temperature dependence of the hydration free energy of small hydrophobes are consistent with the experimental and simulational data on the hydration of simple molecular solutes. Three alternative definitions for the small-to-large crossover length-scale of hydrophobic hydration are proposed, and their temperature dependence is obtained. Depending on the definition and temperature, the small-to-large crossover in the hydration mechanism is predicted to occur for hydrophobes of radii from one to several nanometers. Independent of its definition, the crossover length-scale is predicted to decrease with increasing temperature.

  12. The effect of poverty and social protection on national homicide rates: Direct and moderating effects.

    PubMed

    Rogers, Meghan L; Pridemore, William Alex

    2013-05-01

    Social protection is the ability of a government to insulate its citizens from the problems associated with poverty and market forces that negatively affect their quality of life. Prior research shows that government policies that provide social protection moderate the influence of inequality on national homicide rates. Recent research, however, reveals a strong association between poverty and national homicide rates. Further, theory and evidence suggest that social protection policies are meant to aid in providing a subsistence level of living, and thus to alleviate the vagaries of poverty not inequality. To this point, however, no studies have examined the potentially moderating effect of social protection on the strength of the association between poverty and homicide rates cross-nationally. We do so in the present study. Employing data for the year 2004 from a sample of 30 nations, we estimate a series of weighted least squares regression models to test three hypotheses: the association between poverty and homicide will remain significant and positive when controlling for social protection, social protection will have a significant negative direct effect on national homicide rates, and social protection will diminish the strength of the poverty-homicide association. The results provided evidence supporting all three hypotheses. We situate our findings in the cross-national empirical literature on social structure and homicide and discuss our results in the theoretical context of social protection. PMID:23521982

  13. The effect of strip-mining and reclamation on small mammal communities

    E-print Network

    Waggoner, Kenneth Van

    1975-01-01

    TRE EFFECT OF STRIP-MINING AND RECLAMATION ON SMALL ~L CO?iUITIES A Thesis Kenneth Van Waggoner Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December... land. s and. spoils as much as possible. In certain states (Ohio, Pennsylvania, snd Illinois) strip-mining and reclamation practices are regulated 'by law (Riley, 1954). The purpose of this study is to assess the effects of strip...

  14. Reynolds number and pitch blade effects on aerodynamic performances of small VAWTs in starting phase

    NASA Astrophysics Data System (ADS)

    Dumitrache, Alexandru; Dumitrescu, Horia; Frunzulica, Florin

    2013-10-01

    Many small vertical axis wind tubines operate at Reynolds number around 105, when the NACA series airfoils have some specific aerodynamic characteristics considered as "anomalies". These particularities influence on the turbine performance and their inability to self-start. Therefore, the present paper is focused on the symmetric NACA airfoils which for this Reynolds number range experience a dead band of negative torque at tip speed ratios (TSR) between 1 to 3. The effects of Reynolds number are discussed and the pitch blade effects is experimental evaluated, regarding to the starting phase behaviour.

  15. Moderate acute alcohol intoxication has minimal effect on surround suppression measured with a motion direction discrimination task.

    PubMed

    Read, Jenny C A; Georgiou, Renos; Brash, Claire; Yazdani, Partow; Whittaker, Roger; Trevelyan, Andrew J; Serrano-Pedraza, Ignacio

    2015-01-01

    A well-studied paradox of motion perception is that, in order to correctly judge direction in high-contrast stimuli, subjects need to observe motion for longer in large stimuli than in small stimuli. This effect is one of several perceptual effects known generally as "surround suppression." It is usually attributed to center-surround antagonism between neurons in visual cortex, believed to be mediated by GABA-ergic inhibition. Accordingly, several studies have reported that this index of surround suppression is reduced in groups known to have reduced GABA-ergic inhibition, including older people and people with schizophrenia and major depressive disorder. In this study, we examined the effect on this index of moderate amounts of ethanol alcohol. Among its many effects on the nervous system, alcohol potentiates GABA-ergic transmission. We therefore hypothesized that it should further impair the perception of motion in large stimuli, resulting in a stronger surround-suppression index. This prediction was not borne out. Alcohol consumption slightly worsened duration thresholds for both large and small stimuli, but their ratio did not change significantly. PMID:25583875

  16. Disproportionate effects of non-colonial small herbivores on structure and diversity of grassland dominated by large herbivores

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The response of semiarid grasslands to small, non-colonial herbivores has received little attention, focusing primarily on the effects of granivore assemblages on annual plant communities. We studied the long-term effects of small and large herbivores on vegetation structure and species diversity of...

  17. Pages 41-52 Short-term effects of small dam removal on a freshwater mussel assemblage.

    E-print Network

    Kwak, Thomas J.

    Pages 41-52 Short-term effects of small dam removal on a freshwater mussel assemblage. Ryan J 1053-637X EDITORIAL REVIEW BOARD #12;SHORT-TERM EFFECTS OF SMALL DAM REMOVAL ON A FRESHWATER MUSSEL 27606 U.S.A. chris_eads@ncsu.edu 1 Corresponding Author ABSTRACT Dam removal is increasingly used

  18. Ethanol Blend Effects On Direct Injection Spark-Ignition Gasoline Vehicle Particulate Matter Emissions

    Microsoft Academic Search

    John Morse Storey; Samuel Arthur Lewis Sr; Teresa L Barone

    2010-01-01

    Direct injection spark-ignition (DISI) gasoline engines can offer better fuel economy and higher performance over their port fuel-injected counterparts, and are now appearing increasingly in more U.S. vehicles. Small displacement, turbocharged DISI engines are likely to be used in lieu of large displacement engines, particularly in light-duty trucks and sport utility vehicles, to meet fuel economy standards for 2016. In

  19. Direct observation of rupture propagation during the 2011 off the Pacific coast of Tohoku Earthquake ( M w 9.0) using a small seismic array

    NASA Astrophysics Data System (ADS)

    Nakahara, Hisashi; Sato, Haruo; Nishimura, Takeshi; Fujiwara, Hiroyuki

    2011-07-01

    A great earthquake of M w 9.0 occurred on March 11, 2011 off the coast of Tohoku region, Northeast Honshu, Japan. Strong ground motions from the earthquake were recorded at 4 stations of a small seismic array, with an aperture of about 500 m, located 120 km away from the epicenter. Peak ground acceleration exceed the full scale of 2 g on the horizontal components, and was larger than 1 g even on the vertical component. Two prominent bursts and at least two following smaller bursts are identified on the strong-motion records which lasted for longer than 200 s. We have performed semblance analysis to estimate the rupture propagation during the earthquake using coherent seismograms at frequencies of 0.5-2 Hz. The rupture seems to consist of at least four stages. Rupture propagated in a northerly direction in the beginning 50 s forming the first burst, then proceeded to the southwest from the epicenter in the next 50 s during the second burst. The rupture further extended southwests in the following 40 s, and finally migrated to the south for about 30 s. A small seismic array makes it possible to observe rupture propagation during a large earthquake even with a small number of stations.

  20. Starting small and ending big -- the effect of monetary incentives on response rates in the 2003 Survey of Small Business Finances: an observational experiment

    Microsoft Academic Search

    Traci L. Mach; Lieu N. Hazelwood; John D. Wolken

    2008-01-01

    In 2003, the Survey of Small Business Finances (SSBF), conducted by the Federal Reserve Board, implemented the use of incentives to increase response rates. This study examines the effects of some of the characteristics of the implementation - such as level of effort, time in queue, and consecutively-increasing incentive amounts - on unit response. Our estimates suggest that as the

  1. Protective effect of geranylgeranylacetone against loxoprofen sodium-induced small intestinal lesions in rats.

    PubMed

    Iwai, Tomohisa; Ichikawa, Takafumi; Kida, Mitsuhiro; Goso, Yukinobu; Kurihara, Makoto; Koizumi, Wasaburo; Ishihara, Kazuhiko

    2011-02-10

    Nonsteroidal anti-inflammatory drugs induce small intestinal ulcers but the preventive measures against it remain unknown. So we evaluated the effect of geranylgeranylacetone (GGA), a mucosal protectant, on both the mucus content and loxoprofen sodium-induced lesions in the rat small intestine. Normal male Wistar rats were given GGA (200 or 400mg/kg p.o.) and euthanized 3h later for measurement of mucin content and immunoreactivity. Other Wistar rats were given loxoprofen sodium (30mg/kg s.c.) and euthanized 24h later. GGA (30-400mg/kg p.o.) was administered twice: 30min before and 6h after loxoprofen sodium. The total mucin content of the small intestinal mucosa increased, especially the ratio of sialomucin, which increased approximately 20% more than the control level after a single dose of GGA. Loxoprofen sodium provoked linear ulcers along the mesenteric margin of the distal jejunum, accompanied by an increase in enterobacterial translocation. Treatment of the animals with GGA dose-dependently prevented the development of intestinal lesions, and bacterial translocation following loxoprofen sodium was also significantly decreased. GGA protects the small intestine against loxoprofen sodium-induced lesions, probably by inhibiting enterobacterial invasion of the mucosa as a result of the increase in the mucosal barrier. PMID:21130762

  2. Direct and Terrestrial Vegetation-mediated Effects of Environmental Change on Aquatic Ecosystem Processes

    NSDL National Science Digital Library

    Becky Ball (Dartmouth College; )

    2010-09-01

    Global environmental changes have direct effects on aquatic ecosystems, as well as indirect effects through alterations of adjacent terrestrial ecosystem structure and functioning. For example, shifts in terrestrial vegetation communities resulting from global changes can affect the quantity and quality of water, organic matter, and nutrient inputs to aquatic ecosystems. The relative importance of these direct and terrestrial-vegetation-mediated effects is largely unknown, but understanding them is essential to our ability to predict the consequences of global changes for aquatic ecosystems. Here, we present a conceptual framework for considering the relative strengths of these effects and use case studies from xeric, wet and temperate, and boreal ecosystems to demonstrate that the responses of aquatic ecosystems to drivers of global changes may not be evident when the pathways are studied separately. Future studies examining changes in aquatic ecosystem structure and functioning should consider the relative contributions of both direct and terrestrial-vegetation-mediated effects of global changes.

  3. Dynamic Edge Effects in Small Mammal Communities across a Conservation-Agricultural Interface in Swaziland

    PubMed Central

    Hurst, Zachary M.; McCleery, Robert A.; Collier, Bret A.; Fletcher, Robert J.; Silvy, Nova J.; Taylor, Peter J.; Monadjem, Ara

    2013-01-01

    Across the planet, high-intensity farming has transformed native vegetation into monocultures, decreasing biodiversity on a landscape scale. Yet landscape-scale changes to biodiversity and community structure often emerge from processes operating at local scales. One common process that can explain changes in biodiversity and community structure is the creation of abrupt habitat edges, which, in turn, generate edge effects. Such effects, while incredibly common, can be highly variable across space and time; however, we currently lack a general analytical framework that can adequately capture such spatio-temporal variability. We extend previous approaches for estimating edge effects to a non-linear mixed modeling framework that captures such spatio-temporal heterogeneity and apply it to understand how agricultural land-uses alter wildlife communities. We trapped small mammals along a conservation-agriculture land-use interface extending 375 m into sugarcane plantations and conservation land-uses at three sites during dry and wet seasons in Swaziland, Africa. Sugarcane plantations had significant reductions in species richness and heterogeneity, and showed an increase in community similarity, suggesting a more homogenized small mammal community. Furthermore, our modeling framework identified strong variation in edge effects on communities across sites and seasons. Using small mammals as an indicator, intensive agricultural practices appear to create high-density communities of generalist species while isolating interior species in less than 225 m. These results illustrate how agricultural land-use can reduce diversity across the landscape and that effects can be masked or magnified, depending on local conditions. Taken together, our results emphasize the need to create or retain natural habitat features in agricultural mosaics. PMID:24040269

  4. Anti-tumor effect of bisphosphonate (YM529) on non-small cell lung cancer cell lines

    PubMed Central

    Koshimune, Ryuichiro; Aoe, Motoi; Toyooka, Shinichi; Hara, Fumikata; Ouchida, Mamoru; Tokumo, Masaki; Sano, Yoshifumi; Date, Hiroshi; Shimizu, Nobuyoshi

    2007-01-01

    Background YM529 is a newly developed nitrogen-containing bisphosphonate (BP) classified as a third-generation BP that shows a 100-fold greater potency against bone resorption than pamidronate, a second-generation BP. This agent is, therefore expected to be extremely useful clinically for the treatment of osteoporosis and hypercalcemia. Recently, YM529 as well as other third-generation BPs have also been shown to exert anti-tumor effects against various types of cancer cells both in vitro or/and in vivo. In this study, we investigate the anti-tumor effect of YM529 on non-small cell lung cancer (NSCLC). Methods Direct anti-tumor effect of YM529 against 8 NSCLC cell lines (adenocarcinoma: H23, H1299, NCI-H1819, NCI-H2009, H44, A549, adenosquamous cell carcinoma: NCI-H125, squamous cell carcinoma: NCI-H157) were measured by MTS assay and calculated inhibition concentration 50 % (IC50) values. YM529 induced apoptosis of NCI-H1819 was examined by DNA fragmentation of 2 % agarose gel electrophoresis and flowcytometric analysis (sub-G1 method). We examined where YM529 given effect to apoptosis of NSCLC cells in signaling pathway of the mevalonate pathway by western blotting analysis. Results We found that there was direct anti-tumor effect of YM529 on 8 NSCLC cell lines in a dose-dependent manner and their IC50 values were 2.1 to 7.9 ?M and YM529 induced apoptosis and G1 arrest cell cycle with dose-dependent manner and YM529 caused down regulation of phospholyration of ERK1/2 in signaling pathways of NSCLC cell line (NCI-H1819). Conclusion Our study demonstrate that YM529 showed direct anti-tumor effect on NSCLC cell lines in vitro, which supports the possibility that third-generation BPs including YM529 can be one of therapeutic options for NSCLC. PMID:17222343

  5. Effect of fasting in the digestive system: histological study of the small intestine in house sparrows.

    PubMed

    Funes, Samanta Celeste; Filippa, Verónica Palmira; Cid, Fabricio Damián; Mohamed, Fabián; Caviedes-Vidal, Enrique; Chediack, Juan Gabriel

    2014-10-01

    In birds and mammals the metabolic response to fasting has been studied and can be characterized by three consecutive phases reflecting metabolic and physiological adjustments. An effective way to minimize energy expenditure during food scarcity is to decrease the mass of the organs. As the digestive system is metabolically expensive to maintain, the small intestine and the liver are the most affected organs. We evaluated the effects of phase III starvation on the mass of the different organs and histological parameters on house sparrows, a small non-migrant bird. In a short period of time (34 h) we observed a larger reduction in the digestive organ mass when compared to the mass of the body and non-alimentary tissues. Furthermore, the intestinal mass was proportionally more reduced than its length and nominal surface area. A reduction on the intestinal mucosal layer also resulted in a shortening of villus (length and thickness) and crypt depth. Moreover, the morphology of the enterocytes changed from cylindrical to cubical, suggesting that the surface exposed to the lumen was conserved. This may indicate an adaptive response to the moment of refeeding. The nominal surface area/body mass remained constant in both groups and several histological parameters were reduced, suggesting that starving induces the atrophy of the small intestine. However, the goblet cells were conserved after fasting indicating a protective tendency. PMID:25035101

  6. Analytical characterization of four wave mixing effect in direct-detection double-sideband OFDM optical transmission systems.

    PubMed

    Alves, Tiago M F; Cartaxo, Adolfo V T

    2014-04-01

    A closed-form expression for the variance of the four-wave mixing (FWM) induced in each subcarrier of a double sideband orthogonal frequency division multiplexing (OFDM) system employing direct detection is proposed and validated. Particularly, using a small signal analysis, equivalent transfer functions that characterize the frequency response of the FWM effect are derived taking into account the walkoff effect between the modulated pump waves and the FWM wave. The accuracy of the variance estimates provided by the closed-form expression is assessed for different sets of system parameters. The closed-form expression provides good variance estimates of the FWM-induced degradation caused by degenerate and nonsymmetric nondegenerate FWM components. For symmetric non-degenerate FWM components, the proposed expression provides reliable but pessimistic variance estimates, not exceeding the actual FWM variance in 1.5 dB for modulation indexes of interest. PMID:24718231

  7. Common Crowding Agents Have Only a Small Effect on Protein-Protein Interactions

    PubMed Central

    Phillip, Yael; Sherman, Eilon; Haran, Gilad; Schreiber, Gideon

    2009-01-01

    Abstract Studies of protein-protein interactions, carried out in polymer solutions, are designed to mimic the crowded environment inside living cells. It was shown that crowding enhances oligomerization and polymerization of macromolecules. Conversely, we have shown that crowding has only a small effect on the rate of association of protein complexes. Here, we investigated the equilibrium effects of crowding on protein heterodimerization of TEM1-?-lactamase with ?-lactamase inhibitor protein (BLIP) and barnase with barstar. We also contrasted these with the effect of crowding on the weak binding pair CyPet-YPet. We measured the association and dissociation rates as well as the affinities and thermodynamic parameters of these interactions in polyethylene glycol and dextran solutions. For TEM1-BLIP and for barnase-barstar, only a minor reduction in association rate constants compared to that expected based on solution viscosity was found. Dissociation rate constants showed similar levels of reduction. Overall, this resulted in a binding affinity that is quite similar to that in aqueous solutions. On the other hand, for the CyPet-YPet pair, aggregation, and not enhanced dimerization, was detected in polyethylene glycol solutions. The results suggest that typical crowding agents have only a small effect on specific protein-protein dimerization reactions. Although crowding in the cell results from proteins and other macromolecules, one may still speculate that binding in vivo is not very different from that measured in dilute solutions. PMID:19651046

  8. Stabilizing effect of small concentrations of PAMAM dendrimers at the insulin aggregation.

    PubMed

    Nowacka, Olga; Shcharbin, Dzmitry; Klajnert-Maculewicz, Barbara; Bryszewska, Maria

    2014-04-01

    Dendrimers' action on proteins and peptides has a dual and controversial character. On one hand, they dissolve prion protein and amyloid fibrils aggregates, which are otherwise only soluble in solvents containing both detergents and high denaturant concentrations. On the other hand they are able to destabilize proteins in generation dependent manner. In present work we estimated the influence of small concentrations (up to 1.4 ?g/ml) of cationic, neutral and anionic poly(amidoamine) dendrimers of 3rd and 4th generations on dithiotreitol induced aggregation of insulin. It was found that cationic dendrimers decreased the insulin aggregation, while anionic and neutral ones did not. At the same time, destabilizing effect of dendrimers on insulin structure was not observed. The conclusion was made that small concentrations of dendrimers can be applied to prevent or decrease the formation of misfolded structures of protein. PMID:24572587

  9. Comparing the effectiveness of small-particle versus large-particle inhaled corticosteroid in COPD

    PubMed Central

    Postma, Dirkje S; Roche, Nicolas; Colice, Gene; Israel, Elliot; Martin, Richard J; van Aalderen, Willem MC; Grigg, Jonathan; Burden, Anne; Hillyer, Elizabeth V; von Ziegenweidt, Julie; Gopalan, Gokul; Price, David

    2014-01-01

    Purpose Small airway changes and dysfunction contribute importantly to airway obstruction in chronic obstructive pulmonary disease (COPD), which is currently treated with inhaled corticosteroids (ICS) and long-acting bronchodilators at Global initiative for Obstructive Lung Disease (GOLD) grades 2–4. This retrospective matched cohort analysis compared effectiveness of a representative small-particle ICS (extrafine beclomethasone) and larger-particle ICS (fluticasone) in primary care patients with COPD. Patients and methods Smokers and ex-smokers with COPD ?40 years old initiating or stepping-up their dose of extrafine beclomethasone or fluticasone were matched 1:1 for demographic characteristics, index prescription year, concomitant therapies, and disease severity during 1 baseline year. During 2 subsequent years, we evaluated treatment change and COPD exacerbations, defined as emergency care/hospitalization for COPD, acute oral corticosteroids, or antibiotics for lower respiratory tract infection. Results Mean patient age was 67 years, 57%–60% being male. For both initiation (n=334:334) and step-up (n=189:189) patients, exacerbation rates were comparable between extrafine beclomethasone and fluticasone cohorts during the 2 year outcome period. Odds of treatment stability (no exacerbation or treatment change) were significantly greater for patients initiating extrafine beclomethasone compared with fluticasone (adjusted odds ratio 2.50; 95% confidence interval, 1.32–4.73). Median ICS dose exposure during 2 outcome years was significantly lower (P<0.001) for extrafine beclomethasone than fluticasone cohorts (315 ?g/day versus 436 ?g/day for initiation, 438 ?g/day versus 534 ?g/day for step-up patients). Conclusion We observed that small-particle ICS at significantly lower doses had comparable effects on exacerbation rates as larger-particle ICS at higher doses, whereas initiation of small-particle ICS was associated with better odds of treatment stability during 2-years’ follow-up. PMID:25378918

  10. Effects of disturbance on small mammal community structure in the New Jersey Pinelands, USA.

    PubMed

    Shenko, Alicia N; Bien, Walter F; Spotila, James R; Avery, Harold W

    2012-03-01

    We compared small mammal community composition among undisturbed habitats and habitats disturbed by military operations on Warren Grove Gunnery Range (WGR) in the New Jersey Pinelands. WGR is one of the largest tracts of protected land within this globally rare ecosystem. Disturbance in the form of fire, mowing, soil disruption and logging has had a large effect on small mammal occurrence and distribution. Of the 14 small mammal species that occur in the Pinelands, 9 live on WGR, including large populations of the southern bog lemming (Synaptomys cooperi Baird, 1858) and meadow jumping mouse [Zapus hudsonius (Zimmermann, 1780)]. Simpson's Index of Diversity was 0 for most disturbed sites and was generally greater in wetlands than in uplands. White-footed mouse [Peromyscus leucopus (Rafinesque, 1818)] was the most common species on WGR and had a dominant effect on species diversity and community similarity indices. It dominated upland habitats and was the only species to occur in several disturbed habitats, whereas all 9 species occurred in wetlands. Principal components analysis indicated that most variation in species diversity was explained by disturbance and differences between upland and wetland habitats, due to presence of white-footed mice in disturbed and upland sites. Meadow jumping mice, southern bog lemmings and red-back voles [Myodes gapperi (Vigors, 1830)] were positively correlated with wetland habitats, and pine voles [Microtus pinetorum (Le Conte, 1830)], short-tail shrews [Blarina brevicauda (Say, 1823)] and eastern chipmunks [Tamias striatus (Linnaeus, 1758)] were associated with uplands. Habitat heterogeneity at WGR, including extensive undisturbed wetlands and uplands supported a rich diversity of small mammal species. PMID:22405445

  11. Effects of Transcranial Direct Current Stimulation (tDCS) on Behaviour and Electrophysiology of Language Production

    ERIC Educational Resources Information Center

    Wirth, Miranka; Rahman, Rasha Abdel; Kuenecke, Janina; Koenig, Thomas; Horn, Helge; Sommer, Werner; Dierks, Thomas

    2011-01-01

    Excitatory anodal transcranial direct current stimulation (A-tDCS) over the left dorsal prefrontal cortex (DPFC) has been shown to improve language production. The present study examined neurophysiological underpinnings of this effect. In a single-blinded within-subject design, we traced effects of A-tDCS compared to sham stimulation over the left…

  12. Negative direct effects of nutrient enrichment on the establishment of Fucus vesiculosus in the Baltic Sea

    Microsoft Academic Search

    Lena Bergström; Rita Berger; Lena Kautsky

    2003-01-01

    The direct effect of nutrient enrichment on the early life stages of Fucus vesiculosus in the brackish Baltic Sea was followed in laboratory experiments. The effects of nitrate and phosphate on the rate of attachment, on germination and on the development of the primary rhizoid were assessed. The rate of attachment was slow compared with similar studies in a marine

  13. Comparing Direct versus Indirect Measures of the Pedagogical Effectiveness of Team Testing

    ERIC Educational Resources Information Center

    Bacon, Donald R.

    2011-01-01

    Direct measures (tests) of the pedagogical effectiveness of team testing and indirect measures (student surveys) of pedagogical effectiveness of team testing were collected in several sections of an undergraduate marketing course with varying levels of the use of team testing. The results indicate that although students perceived team testing to…

  14. The effect of offset charge deposited directly onto single-electron devices

    Microsoft Academic Search

    M. R. Graham; H. Ahmed

    1998-01-01

    The effects of charge deposited directly in the vicinity of a multiple tunnel junction single-electron transistor have been investigated. Two regimes of offset effects have been observed with a continuous transition between them. The deposited charge causes the device current to oscillate in a manner analogous to sweeping the gate voltage, and an equivalence between the two phenomena has been

  15. Lack of Direct Effects of Agrochemicals on Zoonotic Pathogens and Fecal Indicator Bacteria

    PubMed Central

    Staley, Zachery R.; Senkbeil, Jacob K.; Rohr, Jason R.

    2012-01-01

    Agrochemicals, fecal indicator bacteria (FIB), and pathogens frequently contaminate water simultaneously. No significant direct effects of fertilizer, atrazine, malathion, and chlorothalonil on the survival of Escherichia coli, Enterococcus faecalis, Salmonella enterica, human polyomaviruses, and adenovirus were detected, supporting the assertion that previously observed effects of agrochemicals on FIB were indirect. PMID:22961900

  16. Predicting use of effective vegetable parenting practices with the Model of Goal Directed Behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objective was to model effective vegetable parenting practices using the Model of Goal Directed Vegetable Parenting Practices construct scales. An internet survey was conducted with 307 parents (mostly mothers) of preschoolers in Houston, Texas to assess their agreement with effective vegetable ...

  17. Direct effects of incubation temperature on morphology, thermoregulatory behaviour and locomotor performance

    E-print Network

    Keogh, Scott

    Direct effects of incubation temperature on morphology, thermoregulatory behaviour and locomotor May 2014 Keywords: Phenotypic plasticity Incubation temperature Maternal effects Jacky dragons Amphibolurus muricatus a b s t r a c t Incubation temperature is one of the most studied factors driving

  18. Long-term effects of precommercial thinning on small mammals in northern Maine

    USGS Publications Warehouse

    Homyack, J.A.; Harrison, D.J.; Krohn, W.B.

    2005-01-01

    Precommercial thinning (PCT) is being practiced increasingly throughout the Acadian forest of eastern North America to meet silvicultural objectives; however, effects of this practice on wildlife, both immediately and several years post-treatment are not well understood. Forest dependent small mammals have ecological roles as prey for numerous avian and mammalian predators, dispersers of seeds, fruit, and spores, and contribute to nutrient cycling. Researchers in the northwestern USA have suggested that thinning of young, regenerating clearcuts may increase the abundance and diversity of some forest-dependent small mammals by increasing rates of forest development and enhancing the ecological representation of mid-successional stands across managed landscapes. We examined the effects of PCT within conifer-dominated forest stands 1-, 6-, 11-, and 16-years post-treatment, on abundances of mice, voles, and shrews, and on within-stand structure in the commercially managed, Acadian forests of northern Maine. We live-trapped small mammals on 24 herbicide-treated clearcuts treated with PCT and on 13 similar, unthinned stands during summers of 2000 and 2001. Thinning of mid-successional conifer stands resulted in increased abundances, (red-backed voles, Clethrionomys gapperi, P = 0.008; masked shrews, Sorex cinereus, P < 0.001) or had no detectable effect on (deer mice, Peromyscus maniculatus, P = 0.544; short-tailed shrews, Blarina brevicauda, P = 0.517) the 4 most common species of Muridae and Soricidae in northern Maine. In general, abundance of deer mice responded more positively to increasing development class and to the number of years since thinning than other species of small mammals. Several within-stand habitat characteristics associated with stand maturity, such as larger stem diameters and a partially open canopy, occurred in thinned stands. Thus, PCT may accelerate the development of habitat attributes typical of mid-successional conifer stands in intensively managed stands within the Acadian Forest. PCT may increase abundances of small mammal species associated with mid-seral forest conditions at the scale of the forest stand. ?? 2004 Elsevier B.V. All rights reserved.

  19. Quantifying small molecule phenotypic effects using mitochondrial morpho-functional fingerprinting and machine learning

    NASA Astrophysics Data System (ADS)

    Blanchet, Lionel; Smeitink, Jan A. M.; van Emst-de Vries, Sjenet E.; Vogels, Caroline; Pellegrini, Mina; Jonckheere, An I.; Rodenburg, Richard J. T.; Buydens, Lutgarde M. C.; Beyrath, Julien; Willems, Peter H. G. M.; Koopman, Werner J. H.

    2015-01-01

    In primary fibroblasts from Leigh Syndrome (LS) patients, isolated mitochondrial complex I deficiency is associated with increased reactive oxygen species levels and mitochondrial morpho-functional changes. Empirical evidence suggests these aberrations constitute linked therapeutic targets for small chemical molecules. However, the latter generally induce multiple subtle effects, meaning that in vitro potency analysis or single-parameter high-throughput cell screening are of limited use to identify these molecules. We combine automated image quantification and artificial intelligence to discriminate between primary fibroblasts of a healthy individual and a LS patient based upon their mitochondrial morpho-functional phenotype. We then evaluate the effects of newly developed Trolox variants in LS patient cells. This revealed that Trolox ornithylamide hydrochloride best counterbalanced mitochondrial morpho-functional aberrations, effectively scavenged ROS and increased the maximal activity of mitochondrial complexes I, IV and citrate synthase. Our results suggest that Trolox-derived antioxidants are promising candidates in therapy development for human mitochondrial disorders.

  20. Quantifying small molecule phenotypic effects using mitochondrial morpho-functional fingerprinting and machine learning.

    PubMed

    Blanchet, Lionel; Smeitink, Jan A M; van Emst-de Vries, Sjenet E; Vogels, Caroline; Pellegrini, Mina; Jonckheere, An I; Rodenburg, Richard J T; Buydens, Lutgarde M C; Beyrath, Julien; Willems, Peter H G M; Koopman, Werner J H

    2015-01-01

    In primary fibroblasts from Leigh Syndrome (LS) patients, isolated mitochondrial complex I deficiency is associated with increased reactive oxygen species levels and mitochondrial morpho-functional changes. Empirical evidence suggests these aberrations constitute linked therapeutic targets for small chemical molecules. However, the latter generally induce multiple subtle effects, meaning that in vitro potency analysis or single-parameter high-throughput cell screening are of limited use to identify these molecules. We combine automated image quantification and artificial intelligence to discriminate between primary fibroblasts of a healthy individual and a LS patient based upon their mitochondrial morpho-functional phenotype. We then evaluate the effects of newly developed Trolox variants in LS patient cells. This revealed that Trolox ornithylamide hydrochloride best counterbalanced mitochondrial morpho-functional aberrations, effectively scavenged ROS and increased the maximal activity of mitochondrial complexes I, IV and citrate synthase. Our results suggest that Trolox-derived antioxidants are promising candidates in therapy development for human mitochondrial disorders. PMID:25620325

  1. Quantifying small molecule phenotypic effects using mitochondrial morpho-functional fingerprinting and machine learning

    PubMed Central

    Blanchet, Lionel; Smeitink, Jan A. M.; van Emst - de Vries, Sjenet E.; Vogels, Caroline; Pellegrini, Mina; Jonckheere, An I.; Rodenburg, Richard J. T.; Buydens, Lutgarde M. C.; Beyrath, Julien; Willems, Peter H. G. M.; Koopman, Werner J. H.

    2015-01-01

    In primary fibroblasts from Leigh Syndrome (LS) patients, isolated mitochondrial complex I deficiency is associated with increased reactive oxygen species levels and mitochondrial morpho-functional changes. Empirical evidence suggests these aberrations constitute linked therapeutic targets for small chemical molecules. However, the latter generally induce multiple subtle effects, meaning that in vitro potency analysis or single-parameter high-throughput cell screening are of limited use to identify these molecules. We combine automated image quantification and artificial intelligence to discriminate between primary fibroblasts of a healthy individual and a LS patient based upon their mitochondrial morpho-functional phenotype. We then evaluate the effects of newly developed Trolox variants in LS patient cells. This revealed that Trolox ornithylamide hydrochloride best counterbalanced mitochondrial morpho-functional aberrations, effectively scavenged ROS and increased the maximal activity of mitochondrial complexes I, IV and citrate synthase. Our results suggest that Trolox-derived antioxidants are promising candidates in therapy development for human mitochondrial disorders. PMID:25620325

  2. Complementary effects of gaze direction and early saliency in guiding fixations during free viewing.

    PubMed

    Borji, Ali; Parks, Daniel; Itti, Laurent

    2014-01-01

    Gaze direction provides an important and ubiquitous communication channel in daily behavior and social interaction of humans and some animals. While several studies have addressed gaze direction in synthesized simple scenes, few have examined how it can bias observer attention and how it might interact with early saliency during free viewing of natural and realistic scenes. Experiment 1 used a controlled, staged setting in which an actor was asked to look at two different objects in turn, yielding two images that differed only by the actor's gaze direction, to causally assess the effects of actor gaze direction. Over all scenes, the median probability of following an actor's gaze direction was higher than the median probability of looking toward the single most salient location, and higher than chance. Experiment 2 confirmed these findings over a larger set of unconstrained scenes collected from the Web and containing people looking at objects and/or other people. To further compare the strength of saliency versus gaze direction cues, we computed gaze maps by drawing a cone in the direction of gaze of the actors present in the images. Gaze maps predicted observers' fixation locations significantly above chance, although below saliency. Finally, to gauge the relative importance of actor face and eye directions in guiding observer's fixations, in Experiment 3, observers were asked to guess the gaze direction from only an actor's face region (with the rest of the scene masked), in two conditions: actor eyes visible or masked. Median probability of guessing the true gaze direction within ±9° was significantly higher when eyes were visible, suggesting that the eyes contribute significantly to gaze estimation, in addition to face region. Our results highlight that gaze direction is a strong attentional cue in guiding eye movements, complementing low-level saliency cues, and derived from both face and eyes of actors in the scene. Thus gaze direction should be considered in constructing more predictive visual attention models in the future. PMID:25371549

  3. Effect of small-molecule modification on single-cell pharmacokinetics of PARP inhibitors.

    PubMed

    Thurber, Greg M; Reiner, Thomas; Yang, Katherine S; Kohler, Rainer H; Weissleder, Ralph

    2014-04-01

    The heterogeneous delivery of drugs in tumors is an established process contributing to variability in treatment outcome. Despite the general acceptance of variable delivery, the study of the underlying causes is challenging, given the complex tumor microenvironment including intra- and intertumor heterogeneity. The difficulty in studying this distribution is even more significant for small-molecule drugs where radiolabeled compounds or mass spectrometry detection lack the spatial and temporal resolution required to quantify the kinetics of drug distribution in vivo. In this work, we take advantage of the synthesis of fluorescent drug conjugates that retain their target binding but are designed with different physiochemical and thus pharmacokinetic properties. Using these probes, we followed the drug distribution in cell culture and tumor xenografts with temporal resolution of seconds and subcellular spatial resolution. These measurements, including in vivo permeability of small-molecule drugs, can be used directly in predictive pharmacokinetic models for the design of therapeutics and companion imaging agents as demonstrated by a finite element model. PMID:24552776

  4. Effect of Small Molecule Modification on Single Cell Pharmacokinetics of PARP Inhibitors

    PubMed Central

    Thurber, Greg M.; Reiner, Thomas; Yang, Katherine S; Kohler, Rainer; Weissleder, Ralph

    2014-01-01

    The heterogeneous delivery of drugs in tumors is an established process contributing to variability in treatment outcome. Despite the general acceptance of variable delivery, the study of the underlying causes is challenging given the complex tumor microenvironment including intra- and inter-tumor heterogeneity. The difficulty in studying this distribution is even more significant for small molecule drugs where radiolabeled compounds or mass spectrometry detection lack the spatial and temporal resolution required to quantify the kinetics of drug distribution in vivo. In this work, we take advantage of the synthesis of fluorescent drug conjugates that retain their target binding but are designed with different physiochemical and thus pharmacokinetic properties. Using these probes, we followed the drug distribution in cell culture and tumor xenografts with temporal resolution of seconds and subcellular spatial resolution. These measurements, including in vivo permeability of small molecule drugs, can be used directly in predictive pharmacokinetic models for the design of therapeutics and companion imaging agents as demonstrated by a finite element model. PMID:24552776

  5. Can bioadhesive nanoparticles allow for more effective particle uptake from the small intestine?

    PubMed

    Reineke, J; Cho, D Y; Dingle, Y L; Cheifetz, P; Laulicht, B; Lavin, D; Furtado, S; Mathiowitz, E

    2013-09-28

    There has been increasing interest in developing bioadhesive nanoparticles due to their great potential as carriers for therapeutics in oral drug delivery systems. Despite decades of research, such a system still has not been successfully implemented. This paper demonstrates the enormous potential of such engineered systems: the incorporation of a bioadhesive coating, poly(butadiene-maleic anhydride-co-L-DOPA) (PBMAD), to non-bioadhesive nanospheres resulted in an enhancement of particle uptake in the small intestine from 5.8±1.9% to 66.9±12.9%. Direct correlation was obtained between bulk tensile strength, in vitro binding to everted intestinal sacs and quantitative in vivo uptake; this data suggests that bulk properties of polymers can be used to predict bioadhesive properties of nano- and microparticles. The differential distribution of the nanospheres to various tissues following uptake suggests surface chemistry plays a significant role in their localization within the body. The results of these studies provide strong support for the use of bioadhesive polymers to enhance nano- and micro-particle uptake from the small intestine for oral drug delivery. PMID:23796432

  6. Ground Motion Prediction Equations in the San Jacinto Fault Zone: Significant Effects of Rupture Directivity and Fault Zone Amplification

    NASA Astrophysics Data System (ADS)

    Kurzon, I.; Vernon, F. L.; Ben-Zion, Y.; Atkinson, G.

    2014-11-01

    We present a new set of Ground Motion Prediction Equations (GMPEs) for horizontal Peak Ground Acceleration, Peak Ground Velocity, and 5 % damped pseudo-spectral acceleration (PSA), developed for the San Jacinto Fault Zone (SJFZ) area. Besides using these equations to quantify seismic shaking in the area, the results allow us to examine the physics and local properties controlling the observed ground motions. The analyzed dataset includes ~30,000 observations from ~800 events spanning a magnitude range of 1.5 < M < 6.0 and recorded by up to 140 stations at epicentral distances ranging from essentially zero to 150 km. The local GMPE is developed for the SJFZ by applying classical regression techniques with predictive variables that include first distance and magnitude, and then site characteristics, rupture directivity, and fault zone amplification. The significance of these effects is determined by measuring the uncertainty-reduction of the GMPE due to each factor. The results show that, in contrast to many regional studies, traditional site characteristic has a relatively minor effect on peak amplitudes in our study area. However, rupture directivity is a significant factor controlling the amplitudes of ground motion even for small events. The dense seismic network and newly developed directivity tool enable us to extract efficiently directivity effects with statistical significance, using the ground-motion dataset during the regression analysis process. The obtained rupture directivities are consistent with the main focal mechanism orientations and surface trace orientations, known from other studies, and predictions for bimaterial ruptures in the trifurcation area of the SJFZ. Fault zone amplification is a second important factor, showing strong impact on the peak ground motion values, with increasing role for the lower frequency range (<10 Hz) examined in the 5 % damped PSA values. We also observe signatures of large amplitude-variances, which indicate additional source-related control on the distribution of amplitudes (besides rupture directivity) for aftershocks close in time and location to the M L 5.1 earthquake of March 2013. Using the full set of records we present the most complete set of GMPEs for the SJFZ area, including a higher-amplitude prediction for regions in the direction of rupture.

  7. The effects of long-term captivity on the metabolic parameters of a small Afrotropical bird.

    PubMed

    Thompson, Lindy J; Brown, Mark; Downs, Colleen T

    2015-04-01

    The few within-species studies on the effects of long-term captivity on avian physiological variables have small samples sizes and contradictory results. Nevertheless, many physiological studies make use of long-term captive birds, assuming the results will be applicable to wild populations. Here we investigated the effects of long-term captivity on a variety of physiological measurements in a relatively small (~12 g) southern African endemic bird, the Cape white-eye (Zosterops virens). Whole animal basal metabolic rate (BMR) and body mass (Mb) were influenced more by long-term captivity than by season, while mass-specific BMR, standard and basal whole animal and mass-specific evaporative water loss (EWL), and respiratory quotient (RQ), were all affected primarily by season, with long-term captivity having less of an effect. We therefore caution that whole animal BMR and Mb of long-term captive birds should not be used as representative of wild populations, and that the origin of study birds should be considered when comparing EWL and RQ of wild and long-term captive birds. PMID:25636901

  8. [Effects of UV radiation on the aggregation performance of small molecular organic acids].

    PubMed

    Wang, Wen-Dong; Wang, Ya-Bo; Fan, Qing-Hai; Ding, Zhen-Zhen; Wang, Wen; Song, Shan; Zhang, Yin-Ting

    2014-10-01

    This study systematically investigated the effects of UV radiation on the aggregation of small molecular aliphatic carboxylic acids and phenolic acids by jar test. Experimental results show that solution pH has little effect on the coagulation of small molecular aliphatic carboxylic acids including citric acid, oxalic acid, tartaric acid, and succinic acid. For the solutions pretreated with UV light, the removal rates of the selected aliphatic carboxylic acids in coagulation are higher than that without UV radiation. Further study shows that photochemical reactions occur during UV radiation which decreases the negative charge in aliphatic carboxylic acids, and thereby increases their aggregation properties. Different from aliphatic carboxylic acids, phenol, salicylic acid, and benzoic acid have poor coagulation properties, and UV radiation does not have notable effects on their aggregation in the coagulation process. The coagulation performance of tannic acid is better than the other phenolic acids. At pH = 6, its removal rate is above 90%, which may be contributed to the aliphatic carboxylic acid structure in its molecular. Meanwhile, the large molecular of tannic acid is also easier to be adsorbed by the hydrolysis products of PAC1. PMID:25693384

  9. Using an Index of Biotic Integrity to Assess the Effects of Conservation in Small Watersheds

    NASA Astrophysics Data System (ADS)

    Teels, B. M.

    2002-05-01

    During the past century, the use of biological indicators to monitor environmental quality has evolved from simple diversity indexes into a variety of approaches. One of the more recent and successful has been the development of the Index of Biotic Integrity (IBI), a multimetric approach that uses species assemblages to assess the biological condition of streams. Now well documented and widely used, the IBI combines multiple metrics with appropriate sampling design and statistical analysis to evaluate a stream's ability to support undisturbed living systems. In this study, an IBI tailored for small watersheds was used to characterize the condition of Northern Virginia streams and serve as a benchmark to measure the effects of future conservation in that region. Metrics for the IBI were chosen on the basis of how well they reflected specific and predictable responses of fish assemblages to human influences. The process for selecting metrics involved the testing of a larger set of biological attributes to select those few metrics that were highly sensitive, yet not redundant. A gradient of human influence was established for the region to help evaluate the performance of each individual metric. The study concluded that by adapting the technique to account for regional variations in human influence and fish fauna, an IBI can effectively measure the condition of streams and small watersheds. The study also concluded that the IBI has potential for evaluating the effectiveness of locally applied conservation measures, such as riparian buffers, in restoring aquatic health.

  10. Dynamical Casimir Effect in a small compact manifold for the Maxwell vacuum

    E-print Network

    Ariel R. Zhitnitsky

    2015-01-29

    We study novel type of contributions to the partition function of the Maxwell system defined on a small compact manifold ${\\mathbb{M}}$ such as torus. These new terms can not be described in terms of the physical propagating photons with two transverse polarizations. Rather, these novel contributions emerge as a result of tunnelling events when transitions occur between topologically different but physically identical vacuum winding states. These new terms give an extra contribution to the Casimir pressure, yet to be measured. We argue that if the same system is considered in the background of a small external time-dependent magnetic field, than there will be emission of photons from the vacuum, similar to the Dynamical Casimir Effect (DCE) when real particles are radiated from the vacuum due to the time-dependent boundary conditions. The difference with conventional DCE is that the dynamics of the vacuum in our system is not related to the fluctuations of the conventional degrees of freedom, the virtual photons. Rather, the radiation in our case occurs as a result of tunnelling events between topologically different but physically identical $|k>$ sectors in a time -dependent background. We comment on relation of this novel effect with the well-known, experimentally observed, and theoretically understood phenomena of the persistent currents in normal metal rings. We also comment on possible cosmological applications of this effect.

  11. Analyzing the Effects of Spatial Resolution for Small Landslide Susceptibility and Hazard Mapping

    NASA Astrophysics Data System (ADS)

    Mora, O. E.; Lenzano, M. G.; Toth, C. K.; Grejner-Brzezinska, D. A.

    2014-11-01

    Spatial resolution plays an important role in remote sensing technology as it defines the smallest scale at which surface features may be extracted, identified, and mapped. Remote sensing technology has become a vital component in recent developments for landslide susceptibility mapping. The spatial resolution is essential, especially when landslides are small and the dimensions of slope failures vary. If the spatial resolution is relevant to the surface features found in the landslide morphology, it will help improve the extraction, identification and mapping of landslide surface features. Although, the spatial resolution is a well-known issue, few studies have demonstrated the potential effects it may have on small landslide susceptibility mapping. For these reasons, an evaluation to assess the impact of spatial resolution was performed using data acquired along a transportation corridor in Zanesville, Ohio. Using a landslide susceptibility mapping algorithm, landslide surface features were extracted and identified on a cell-by-cell basis from Digital Elevation Models (DEM) generated at 50, 100, 200 and 400 cm spatial resolution. The performance of the landslide surface feature extraction algorithm was then evaluated using an inventory map and a confusion matrix to assess the effects of spatial resolution. In addition to assessing the performance of the algorithm, we statistically analyzed the surface features and their relevant patterns. The results from this evaluation reveal patterns caused by the varying spatial resolution. From this study we can conclude that the spatial resolution has an effect on the accuracy and surface features extracted for small landslide susceptibility mapping, as the performance is dependent on the scale of the landslide morphology.

  12. Antispasmodic Effects of Myrrh due to Calcium Antagonistic Effects in Inflamed Rat Small Intestinal Preparations.

    PubMed

    Vissiennon, Cica; Goos, Karl-Heinz; Goos, Ole; Nieber, Karen

    2015-01-01

    Myrrh is the oleo-gum resin of mainly Commiphora molmol and as a powdered substance, one compound in the traditional medicinal product Myrrhinil-Intest®, which has been used for the treatment of unspecific, inflammatory intestinal disorders. The aim of the present study was to evaluate the antispasmodic effect of myrrh under healthy and inflamed conditions, and to evaluate a calcium-antagonistic effect as a possible mode of action. Therefore, an ethanolic myrrh extract was tested for its effects on muscle tone and acetylcholine-induced contractions in untreated and inflamed rat ileum/jejunum preparations. Inflammation was experimentally induced by 2,4,6-trinitrobenzene sulfonic acid (10?mM, 30?min). Additionally, the effect of the calcium channel agonist Bay K8644 in the presence of varying myrrh extract concentrations was examined. Myrrh extract (0.99?mg/mL) suppressed the acetylcholine-induced contraction down to 25.8?% in untreated and 15.2?% in inflamed preparations. Myrrh extract (0.15; 0.25 and 0.35?mg/mL) induced a concentration-dependent rightward shift of the Bay K8644 concentration-response curve in untreated and inflamed preparations with a significant EC50 shift. Schild analysis resulted in a pA2 value of 0.93 for untreated preparations. Increasing myrrh extract concentrations induced a concentration-dependent decrease of the agonistic maximum effect in untreated and inflamed preparations down to 15.8?% and 25.8?%, respectively, for the highest concentration leading to a pD2 value of 0.58. Myrrh extract reduced intestinal muscle tone and acetylcholine-induced contraction of untreated and inflamed ileum/jejunum preparations based on dual calcium antagonism characterized by a right shift of the agonistic dose-response curve and a depression of the maximum effect. The resulting reduction of intestinal motility and spasmolytic effects provide a rationale for the symptom treatment of intestinal disorders such as irritable bowel syndrome. PMID:25590370

  13. Third-order effect in magnetic small-angle neutron scattering by a spatially inhomogeneous medium

    NASA Astrophysics Data System (ADS)

    Metlov, Konstantin L.; Michels, Andreas

    2015-02-01

    Magnetic small-angle neutron scattering (SANS) is a powerful tool for investigating nonuniform magnetization structures inside magnetic materials. Here, we consider a ferromagnetic medium with weakly inhomogeneous uniaxial magnetic anisotropy, saturation magnetization, and exchange stiffness, and derive, to second order in the amplitudes of the inhomogeneities, the micromagnetic solutions for the equilibrium magnetization textures. Further, we compute the corresponding magnetic SANS cross section up to the third order. For the special case of scattering geometry where the incident neutron beam is perpendicular to the applied magnetic field, twice the cross section along the direction orthogonal to both the field and the neutron beam cancels the cross section along the field direction in the second order. This cancellation does not depend on the defect shape and amplitudes of the exchange inhomogeneities. Hence, such a cross-section difference has only a third-order contribution in the amplitudes of the inhomogeneities. It provides a separate gateway for a deeper analysis of the sample's magnetic structure. We derive and analyze analytical expressions for the dependence of this difference on the scattering-vector magnitude for the case of spherical Gaussian inhomogeneities.

  14. Use of Delayed Praise as a Directive and Its Effectiveness on On-Task Behavior

    Microsoft Academic Search

    Dorothy M. Trolinder; Hee-sook Choi; Theron B. Proctor

    2004-01-01

    This study investigated the effectiveness of delayed, directive praise on the on-task behavior of children identified as having a low level of attention. Utilizing an A-B-A-B single subject design, each child received delayed praise, employed as a directive for future behavior, from his or her classroom teacher during the treatment phases. The on-task behavior of each participant rose substantially between

  15. Numerical Experiments for Quantification of Small-Scale Effects in Particle-Laden Turbulent Flow

    Microsoft Academic Search

    Ch. Gobert; M. Manhart

    \\u000a The present work contains results from numerical simulations of particle-laden isotropic turbulence at high Reynolds and Stokes\\u000a numbers (up to Re\\u000a \\u000a ?\\u000a =265 and St=100 based on the Taylor length scale and Kolmogorov time scale, respectively). The focus is on the effect of small-scale\\u000a turbulence on the particles, a modelling issue for LES of particle-laden flow. The results show that

  16. Effects of Small Additions of Copper and Copper + Nickel on the Oxidation Behavior of Iron

    Microsoft Academic Search

    Bryan Webler; Lan Yin; Seetharaman Sridhar

    2008-01-01

    This study was undertaken to investigate the effect of small amounts of copper and copper + nickel additions on the oxidation\\u000a rate and oxide\\/metal interface microstructure of iron. Three iron-based alloys were compared: 0.3 wt pct copper, 0.3 wt pct\\u000a copper-0.1 wt pct nickel, and 0.3 wt pct copper-0.05 wt pct nickel. Alloy samples were oxidized in air at 1150 °C for 60,\\u000a 300, and 600 seconds. Pure iron

  17. Effect of a curved duct upstream on performance of small centrifugal compressors for automobile turbochargers

    NASA Astrophysics Data System (ADS)

    Kikuchi, Shigeta; Yamasaki, Nobuhiko; Yamagata, Akihiro

    2013-02-01

    Since the automobile turbochargers are installed in an engine compartment with limited space, the ducts upstream of the turbocharger compressor may be curved in a complex manner. In the present paper, the effect of a curved duct upstream on performance of small centrifugal compressors for automobile turbochargers is discussed. The computational fluid dynamics (CFD) analysis of a turbocharger compressor validated for the compressor model with the straight pipe applied to the compressor with the curved pipe are executed, and the deterioration of the performance for the curved pipe is confirmed. It is also found that the deterioration of compressor performance is caused by the interaction of the secondary flow and the impeller.

  18. The effect of acute hyperglycaemia on small intestinal motility in normal subjects

    Microsoft Academic Search

    A. Russo; R. Fraser; M. Horowitz

    1996-01-01

    Summary  The effects of hyperglycaemia on postprandial small intestinal motor activity are unclear. Duodenal and jejunal pressures\\u000a and duodeno-caecal transit were measured in eight healthy male volunteers during euglycaemia (blood glucose 4–6 mmol\\/l) and\\u000a hyperglycaemia (blood glucose 12–15 mmol\\/l). Duodenal and jejunal pressures were recorded with a manometric assembly during\\u000a intraduodenal infusion of 100 ml nutrient liquid comprising 14% protein, 31.5%

  19. Polarity-Dependent Transcranial Direct Current Stimulation Effects on Central Auditory Processing

    Microsoft Academic Search

    Andrea Ladeira; Felipe Fregni; Camila Campanhã; Cláudia Aparecida Valasek; Dirk De Ridder; André Russwsky Brunoni; Paulo Sérgio Boggio; Manuel S. Malmierca

    2011-01-01

    Given the polarity dependent effects of transcranial direct current stimulation (tDCS) in facilitating or inhibiting neuronal processing, and tDCS effects on pitch perception, we tested the effects of tDCS on temporal aspects of auditory processing. We aimed to change baseline activity of the auditory cortex using tDCS as to modulate temporal aspects of auditory processing in healthy subjects without hearing

  20. The Effects Of Self-Directed Teams In An Automotive Manufacturing Environment

    Microsoft Academic Search

    David Wayne Shall

    2010-01-01

    \\u000aTHE EFFECTS OF SELF DIRECTED TEAMS IN AN AUTOMOTIVE MANUFACTURING ENVIRONMENT\\u000aby\\u000aDAVID W. SHALL\\u000aDecember 2010\\u000aAdvisor:\\u0009James L. Moseley, EdD, LPC, CHES, CPT\\u000aMajor:\\u0009\\u0009Instructional Technology\\u000aDegree:\\u0009Doctor of Philosophy\\u000aThis study compares self-directed work structures to more traditional supervised work structures in order to determine if the expenditures and efforts required to implement self-directed work teams are

  1. The role of small, cost effective spacecraft in the developing countries: the Algerian experience.

    NASA Astrophysics Data System (ADS)

    Bekhti, M.; Benmohamed, M.; Sweeting, M. N.

    2004-11-01

    Small satellites are becoming increasingly important in the context of capability building in space technology for the developing countries. The use of commercial of the shelf technology "COST" and focus on specific missions can speed up the development process, providing faster as well as cheaper access to space. This paper describes a highly successful small satellite programme which has also demonstrated a rapid, cost effective method of transferring expertise in spacecraft engineering, satellite orbital manoeuvres and orbital operations for a core team of eleven engineers from the National Centre of Space Techniques using Alsat-1, Algeria's first enhanced earth observation microsatellite. The approach was based on "learning by doing" in a sense that the know how transfer team had to entirely construct and fully test their own training model TM which represents one of SSTL's recent microsatellite missions. The TM microsatellite uses a modular multipurpose bus capable of supporting communications and earth observation payloads. The primary conclusions of this paper are that small satellite programmes can provide low cost, rapid response access to the space environment and an ideal technology transfer mechanism for countries with low financial inputs for space and wishing to take their first steps toward a national space programme.

  2. Effect of viscous fiber (guar) on postprandial motor activity in human small bowel.

    PubMed

    Schönfeld, J; Evans, D F; Wingate, D L

    1997-08-01

    Both caloric value and chemical composition of a meal have been shown to regulate postprandial small bowel motility in dog. In the same species, duration of and contractile activity within the postprandial period also depends on mean viscosity. It is unknown, however, whether meal viscosity and fiber content also regulate small bowel motor activity in man. In human volunteers, we therefore studied the effect of guar gum on small bowel motor response to liquid and solid meals. Twenty-six prolonged ambulatory small bowel manometry studies were performed in 12 volunteers. A total of 620 hr of recording were analyzed visually for phase III of the MMC and a validated computer program calculated the incidence and amplitude of contractions after ingestion of water (300 ml), a pure glucose drink (300 ml/330 kcal) or a solid meal (530 kcal) with and without 5 g of guar gum. Addition of 5 g of guar gum did not significantly delay reappearance of phase III after ingestion of water (59 +/- 11 vs 106 +/- 21 min; P = 0.09). However, guar gum significantly prolonged duration of postprandial motility pattern both after the glucose drink (123 +/- 19 vs 199 +/- 24 min; P < 0.05) and after the solid meal (310 +/- 92 vs 419 +/- 22 min; P = 0.005). Contractile activity during these periods was not affected by guar gum. This was true for mean incidence of contractions after water (1.9 +/- 0.3 vs 1.8 +/- 0.5 min-1), after the glucose drink (1.6 +/- 0.4 vs. 1.7 +/- 0.3 min-1) and after the solid meal (2.4 +/- 0.4 vs 2.6 +/- 0.4 min-1). Likewise, mean amplitude of contractions was not affected by guar gum after water (22.8 +/- 1.4 vs 20.9 +/- 1.9 mm Hg), after the glucose drink (20.5 +/- 1.4 vs 21.3 +/- 1.2), and after the solid meal (20.3 +/- 1.5 vs 21.5 +/- 1.6 mm Hg). Thus a guar gum-induced increase in chyme viscosity markedly prolonged duration of postprandial motor activity in the human small bowel. Contractile activity within the postprandial period, however, was not affected. We suggest that the postprandial motility pattern persisted longer after the more viscous meals, because gastric emptying and intestinal transit were delayed by guar gum. We conclude that it is essential to define meal viscosity and fiber contents when studying postprandial small bowel motility. PMID:9286225

  3. Anti-obesity effects of 3-hydroxychromone derivative, a novel small-molecule inhibitor of glycogen synthase kinase-3.

    PubMed

    Lee, Sooho; Yang, Woo Kyeom; Song, Ji Ho; Ra, Young Min; Jeong, Jin-Hyun; Choe, Wonchae; Kang, Insug; Kim, Sung-Soo; Ha, Joohun

    2013-04-01

    Glycogen synthase kinase 3 (GSK-3) plays a central role in cellular energy metabolism, and dysregulation of GSK-3 activity is implicated in a variety of metabolic disorders, including obesity, type 2 diabetes, and cancer. Hence, GSK-3 has emerged as an attractive target molecule for the treatment of metabolic disorders. Therefore, this research focused on identification and characterization of a novel small-molecule GSK-3 inhibitor. Compound 1a, a structure based on 3-hydroxychromone bearing isothiazolidine-1,1-dione, was identified from chemical library as a highly potent GSK-3 inhibitor. An in vitro kinase assay utilizing a panel of kinases demonstrated that compound 1a strongly inhibits GSK-3?. The potential effects of compound 1a on the inactivation of GSK-3 were confirmed in human liver HepG2 and human embryonic kidney HEK293 cells. Stabilization of glycogen synthase and ?-catenin, which are direct targets of GSK-3, by compound 1a was assessed in comparison with two other GSK-3 inhibitors: LiCl and SB-415286. In mouse 3T3-L1 preadipocytes, compound 1a markedly blocked adipocyte differentiation. Consistently, intraperitoneal administration of compound 1a to diet-induced obese mice significantly ameliorated their key symptoms such as body weight gain, increased adiposity, dyslipidemia, and hepatic steatosis due to the marked reduction of whole-body lipid level. In vitro and in vivo effects were accompanied by upregulation of ?-catenin stability and downregulation of the expression of several critical genes related to lipid metabolism. From these results, it can be concluded that compound 1a, a novel small-molecule inhibitor of GSK-3, has potential as a new class of therapeutic agent for obesity treatment. PMID:23337568

  4. Synergistic effects of Clostridium perfringens enterotoxin and beta toxin in rabbit small intestinal loops.

    PubMed

    Ma, Menglin; Gurjar, Abhijit; Theoret, James R; Garcia, Jorge P; Beingesser, Juliann; Freedman, John C; Fisher, Derek J; McClane, Bruce A; Uzal, Francisco A

    2014-07-01

    The ability of Clostridium perfringens type C to cause human enteritis necroticans (EN) is attributed to beta toxin (CPB). However, many EN strains also express C. perfringens enterotoxin (CPE), suggesting that CPE could be another contributor to EN. Supporting this possibility, lysate supernatants from modified Duncan-Strong sporulation (MDS) medium cultures of three CPE-positive type C EN strains caused enteropathogenic effects in rabbit small intestinal loops, which is significant since CPE is produced only during sporulation and since C. perfringens can sporulate in the intestines. Consequently, CPE and CPB contributions to the enteropathogenic effects of MDS lysate supernatants of CPE-positive type C EN strain CN3758 were evaluated using isogenic cpb and cpe null mutants. While supernatants of wild-type CN3758 MDS lysates induced significant hemorrhagic lesions and luminal fluid accumulation, MDS lysate supernatants of the cpb and cpe mutants caused neither significant damage nor fluid accumulation. This attenuation was attributable to inactivating these toxin genes since complementing the cpe mutant or reversing the cpb mutation restored the enteropathogenic effects of MDS lysate supernatants. Confirming that both CPB and CPE are needed for the enteropathogenic effects of CN3758 MDS lysate supernatants, purified CPB and CPE at the same concentrations found in CN3758 MDS lysates also acted together synergistically in rabbit small intestinal loops; however, only higher doses of either purified toxin independently caused enteropathogenic effects. These findings provide the first evidence for potential synergistic toxin interactions during C. perfringens intestinal infections and support a possible role for CPE, as well as CPB, in some EN cases. PMID:24778117

  5. Cost-effectiveness of using small vertebrates as indicators of disturbance.

    PubMed

    Peck, Mika Robert; Maddock, Simon T; Morales, Jorge Noe; Oñate, Hugolino; Mafla-Endara, Paola; Peñafiel, Vanessa Aguirre; Torres-Carvajal, Omar; Pozo-Rivera, Wilmer E; Cueva-Arroyo, Xavier A; Tolhurst, Bryony A

    2014-10-01

    In species-rich tropical forests, effective biodiversity management demands measures of progress, yet budgetary limitations typically constrain capacity of decision makers to assess response of biological communities to habitat change. One approach is to identify ecological-disturbance indicator species (EDIS) whose monitoring is also monetarily cost-effective. These species can be identified by determining individual species' responses to disturbance across a gradient; however, such responses may be confounded by factors other than disturbance. For example, in mountain environments the effects of anthropogenic habitat alteration are commonly confounded by elevation. EDIS have been identified with the indicator value (IndVal) metric, but there are weaknesses in the application of this approach in complex montane systems. We surveyed birds, small mammals, bats, and leaf-litter lizards in differentially disturbed cloud forest of the Ecuadorian Andes. We then incorporated elevation in generalized linear (mixed) models (GL(M)M) to screen for EDIS in the data set. Finally, we used rarefaction of species accumulation data to compare relative monetary costs of identifying and monitoring EDIS at equal sampling effort, based on species richness. Our GL(M)M generated greater numbers of EDIS but fewer characteristic species relative to IndVal. In absolute terms birds were the most cost-effective of the 4 taxa surveyed. We found one low-cost bird EDIS. In terms of the number of indicators generated as a proportion of species richness, EDIS of small mammals were the most cost-effective. Our approach has the potential to be a useful tool for facilitating more sustainable management of Andean forest systems. PMID:25124528

  6. Global modelling of direct and indirect effects of sea spray aerosol using a source function encapsulating wave state

    NASA Astrophysics Data System (ADS)

    Partanen, A.-I.; Dunne, E. M.; Bergman, T.; Laakso, A.; Kokkola, H.; Ovadnevaite, J.; Sogacheva, L.; Baisnée, D.; Sciare, J.; Manders, A.; O'Dowd, C.; de Leeuw, G.; Korhonen, H.

    2014-02-01

    Recently developed parameterizations for the sea spray aerosol source flux, encapsulating wave state, and its organic fraction were incorporated into the aerosol-climate model ECHAM-HAMMOZ to investigate the direct and indirect radiative effects of sea spray aerosol particles. Our simulated global sea salt emission of 805 Tg yr-1 (uncertainty range 378-1233 Tg yr-1) was much lower than typically found in previous studies. Modelled sea salt and sodium ion concentrations agreed relatively well with measurements in the smaller size ranges at Mace Head (annual normalized mean model bias -13% for particles with vacuum aerodynamic diameter Dva < 1 ?m), Point Reyes (-29% for particles with aerodynamic diameter Da < 2.5 ?m) and Amsterdam Island (-52% for particles with Da < 1 ?m) but the larger sizes were overestimated (899% for particles with 2.5 ?m effect was positive (0.3 W m-2), in contrast to previous studies. This positive effect was ascribed to the tendency of sea salt aerosol to suppress both the in-cloud supersaturation and the formation of cloud condensation nuclei from sulphate. These effects can be accounted for only in models with sufficiently detailed aerosol microphysics and physics-based parameterizations of cloud activation. However, due to a strong negative direct effect, the simulated effective radiative forcing (total radiative) effect was -0.2 W m-2. The simulated radiative effects of the primary marine organic emissions were small, with a~direct effect of 0.03 W m-2 and an indirect effect of -0.07 W m-2.

  7. Global modelling of direct and indirect effects of sea spray aerosol using a source function encapsulating wave state

    NASA Astrophysics Data System (ADS)

    Partanen, A.-I.; Dunne, E. M.; Bergman, T.; Laakso, A.; Kokkola, H.; Ovadnevaite, J.; Sogacheva, L.; Baisnée, D.; Sciare, J.; Manders, A.; O'Dowd, C.; de Leeuw, G.; Korhonen, H.

    2014-11-01

    Recently developed parameterizations for the sea spray aerosol source flux, encapsulating wave state, and its organic fraction were incorporated into the aerosol-climate model ECHAM-HAMMOZ to investigate the direct and indirect radiative effects of sea spray aerosol particles. Our simulated global sea salt emission of 805 Tg yr-1 (uncertainty range 378-1233 Tg yr-1) was much lower than typically found in previous studies. Modelled sea salt and sodium ion concentrations agreed relatively well with measurements in the smaller size ranges at Mace Head (annual normalized mean model bias -13% for particles with vacuum aerodynamic diameter Dva < 1 ?m), Point Reyes (-29% for particles with aerodynamic diameter Da < 2.5 ?m) and Amsterdam Island (-52% for particles with Da < 1 ?m) but the larger sizes were overestimated (899% for particles with 2.5 ?m < Da < 10 ?m) at Amsterdam Island. This suggests that at least the high end of the previous estimates of sea spray mass emissions is unrealistic. On the other hand, the model clearly underestimated the observed concentrations of organic or total carbonaceous aerosol at Mace Head (-82%) and Amsterdam Island (-68%). The large overestimation (212%) of organic matter at Point Reyes was due to the contribution of continental sources. At the remote Amsterdam Island site, the organic concentration was underestimated especially in the biologically active months, suggesting a need to improve the parameterization of the organic sea spray fraction. Globally, the satellite-retrieved AOD over the oceans, using PARASOL data, was underestimated by the model (means over ocean 0.16 and 0.10, respectively); however, in the pristine region around Amsterdam Island the measured AOD fell well within the simulated uncertainty range. The simulated sea spray aerosol contribution to the indirect radiative effect was positive (0.3 W m-2), in contrast to previous studies. This positive effect was ascribed to the tendency of sea salt aerosol to suppress both the in-cloud supersaturation and the formation of cloud condensation nuclei from sulfate. These effects can be accounted for only in models with sufficiently detailed aerosol microphysics and physics-based parameterizations of cloud activation. However, due to a strong negative direct effect, the simulated effective radiative forcing (total radiative) effect was -0.2 W m-2. The simulated radiative effects of the primary marine organic emissions were small, with a direct effect of 0.03 W m-2 and an indirect effect of -0.07 W m-2.

  8. Effect of additives on distributions of lamellar structures in sheared polymer: a study of synchrotron small-angle x-ray scattering

    NASA Astrophysics Data System (ADS)

    Zhu, Peng-Wei; Edward, Graham; Nichols, Lance

    2009-12-01

    The effects of additives on the distributions of lamellar morphology and orientation in sheared isotactic polypropylene were investigated using the small beam of synchrotron small-angle x-ray scattering. The Cu-phthalocyanine can template the lamellar orientation even under low shear rates, whereas the ultramarine blue cannot. The surface contact is suggested to play a role in stabilizing the formation of oriented nuclei which subsequently direct the growth of oriented lamellae. The additives have no notable effects on the long spacing in the shear region. However, at high shear rates, they decrease the thickness of crystalline lamellae or increase the thickness of amorphous lamellae. Since the additives increase the degree of volume crystalline in the shear region, the number of crystalline lamellae should be increased. The results are helpful in designing and selecting suitable additives for controlling lamellar morphology and orientation.

  9. Small high directivity ferrite antennas

    NASA Astrophysics Data System (ADS)

    Wright, T. M. B.

    A centimeter-wavelength antenna of millimetric dimensions, which uses the intrinsic angular sensitivity of ferrites, is described, with an emphasis on the modification of the material's permeability. The construction of both the ferrite film lens antenna and the ferrite film cassegrain antenna are detailed; both can be devised in a number of configurations for appropriate beam positioning and rf filtering. The antenna design, discussed primarily in the context of smart missiles, electronic warfare, and satellite systems, presents the possibility of magnetically switching between the transmit and receive modes within the antenna structure itself. Finally, it is noted that for a simple 2-dipole array the angular resolution can be two orders of magnitude higher than with the conventional techniques.

  10. High-frequency directivity effects: evidence from analysis of the Les Saintes records

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Letort, J.; Cotton, F.; Drouet, S.

    2014-07-01

    The main-shock (Mw, 6.3) and the aftershocks of the `Les Saintes' earthquake sequence (French Indies) were analyzed to quantify high-frequency directivity effects. A correction method was applied to isolate source spectra within a large frequency range (0.5 to 25 Hz). Most of the aftershocks source spectra are fully consistent with a Brune spectrum point-source shape and do not show any azimuthal dependence. The main-shock (Mw, 6.3) and the two largest aftershocks (Mw, 5.8, 5.3) show, however, a clear azimuthal dependence that indicates significant directivity effect. The discrepancy of the radiated spectral energy and the change in the corner frequencies introduced by directivity effects show that such an effect is significant at high frequency (from 1 to 25 Hz). Our data suggest that the amplitudes in the main-shock Fourier spectrum at directive sites are around a factor of 2.5 higher with respect to anti-directive sites.

  11. Effect of an inlet temperature disturbance on the propagation of methane-air premixed flames in small tubes

    SciTech Connect

    Kim, Nam Il [School of Mechanical Engineering, Chung-Ang University, 221, Heukseok, Dongjak, Seoul 156-756 (Korea)

    2009-07-15

    A flame stabilized in a tube is affected by the temperature disturbance and velocity profile at the inlet boundary. Thus, a multi-dimensional analysis is necessary near the flame. The deviation between one-dimensional and two-dimensional analyses near the flame was investigated quantitatively. The temperature profile in the radial direction was varied to investigate its effects on the propagation of methane-air premixed flames in small tubes. A numerical experiment with Navier-Stokes equations, an energy equation and species equations was conducted coupled with a single-step global-reaction model. Three different temperature profiles were examined for slip and no-slip wall boundary conditions. The effect of temperature profiles on the flame propagation velocity and flame shapes was not negligible depending on the magnitude of the temperature deviation and the tube diameter. This study evaluated a critical length scale of a computational domain or a thermal entrance length of a premixed flame over which the inlet temperature disturbance does not affect the flame characteristics. (author)

  12. Direct and indirect effects of mood on risk decision making in safety-critical workers.

    PubMed

    Morgan, James I; Jones, Fiona A; Harris, Peter R

    2013-01-01

    The study aimed to examine the direct influence of specific moods (fatigue, anxiety, happiness) on risk in safety-critical decision making. It further aimed to explore indirect effects, specifically, the potential mediating effects of information processing assessed using a goodness-of-simulation task. Trait fatigue and anxiety were associated with an increase in risk taking on the Safety-Critical Personal Risk Inventory (S-CPRI), however the effect of fatigue was partialled out by anxiety. Trait happiness, in contrast was related to less risky decision making. Findings concerning the ability to simulate suggest that better simulators made less risky decisions. Anxious workers were generally less able to simulate. It is suggested that in this safety-critical environment happiness had a direct effect on risk decision making while the effect of trait anxiety was mediated by goodness-of-simulation. PMID:22742773

  13. A small cosmological constant due to non-perturbative quantum effects

    NASA Astrophysics Data System (ADS)

    Holland, Jan; Hollands, Stefan

    2014-06-01

    We propose an explanation for the ‘unnatural smallness’ of the cosmological constant, arguing that the stress-energy tensor of the Standard Model should be given by = ?vac????, with a vacuum energy ?vac that differs from the usual ‘dimensional analysis’ result by an exponentially small factor associated with non-perturbative effects. We substantiate our proposal by a rigorous analysis of a toy model, namely the two-dimensional Gross-Neveu model. The stress energy operator is constructed concretely via the operator-product-expansion, and the inherent ambiguities in its construction are carefully examined. Our result for the vacuum energy is then obtained from the assumptions that (a) the OPE-coefficients have an analytic dependence on g, which we propose to be a generic feature of QFT, and that (b) the vacuum energy vanishes to all orders in perturbation theory. Our result can also be interpreted as saying that, while the semi-classical Einstein’s equation can be fulfilled in Minkowski space at the perturbative level, it cannot at the non-perturbative level. Extrapolating our result from the Gross-Neveu model to the Standard Model, one would expect to find \\rho _vac\\sim \\Lambda ^4 e^{-O(1)/g^2}, where ? is an energy scale such as ? = MH, and g is a gauge coupling such as g2/4? = ?EW. Assuming this extrapolation is justified, the exponentially small factor due to non-perturbative effects would explain why this quantity is tiny, instead of strictly zero.

  14. Effect of membrane thickness of collodion coated activated charcoal on adsorption of small and middle molecules.

    PubMed

    Morley, D; Chang, T M

    1987-01-01

    Different thicknesses of a cellulose nitrate (CN) coating were applied to petroleum pitch bead activated charcoal. The effect of this on the adsorption of small and middle molecules in vitro was studied. This was done by measuring the rate of adsorption of Vitamin B12, creatinine and uric acid from aqueous solution by activated charcoal having CN coatings of varying thickness (0.1% to 4.0% by weight). A CN coating weight of up to 0.2% caused negligible or no decrease in the rate of adsorption of all three solutes as compared with uncoated charcoal. Coating weights greater than 0.2% caused a significant decrease in the rate of adsorption of Vitamin B12, and uric acid but had little effect on the rate of adsorption of creatinine. Coating weights greater than 1.8% caused a significant decrease in the rate of adsorption of creatinine. PMID:3440135

  15. Effects of temporally varying inlet conditions on flow and particle deposition in the small bronchial tubes.

    PubMed

    Soni, Bela; Thompson, David

    2012-09-01

    The laminar flow in the small bronchial tubes is quite complex because of the presence of vortex-dominated, secondary flows. Factors contributing to this complexity are the unsteady nature of the inhale-exhale breathing cycle and the geometrical characteristics of the bronchial tubes. To investigate unsteady effects on flows and particle transport, unsteady inhalation flows at a 30-respiration-per-minute frequency, corresponding to a moderate activity level, were simulated for a three-generation, asymmetric, planar bronchial tube model. Ten-micron diameter water droplets were introduced at the inlet at different times during inhalation to develop particle destination maps. The differences in the flow fields and destination maps obtained at the unsteady peak flow and the comparable steady-state inflow condition were minimal. However, particles released at equivalent instantaneous off-peak inflow conditions produced different destination maps. The differences were attributed to the temporal variations of the fluid velocities and history effects. PMID:22941923

  16. A Central Limit Theorem for the Effective Conductance: Linear Boundary Data and Small Ellipticity Contrasts

    NASA Astrophysics Data System (ADS)

    Biskup, M.; Salvi, M.; Wolff, T.

    2014-06-01

    Given a resistor network on with nearest-neighbor conductances, the effective conductance in a finite set with a given boundary condition is the minimum of the Dirichlet energy over functions with the prescribed boundary values. For shift-ergodic conductances, linear (Dirichlet) boundary conditions and square boxes, the effective conductance scaled by the volume of the box converges to a deterministic limit as the box-size tends to infinity. Here we prove that, for i.i.d. conductances with a small ellipticity contrast, also a (non-degenerate) central limit theorem holds. The proof is based on the corrector method and the Martingale Central Limit Theorem; a key integrability condition is furnished by the Meyers estimate. More general domains, boundary conditions and ellipticity contrasts will be addressed in a subsequent paper.

  17. Fuel properties effect on the performance of a small high temperature rise combustor

    NASA Technical Reports Server (NTRS)

    Acosta, Waldo A.; Beckel, Stephen A.

    1989-01-01

    The performance of an advanced small high temperature rise combustor was experimentally determined at NASA-Lewis. The combustor was designed to meet the requirements of advanced high temperature, high pressure ratio turboshaft engines. The combustor featured an advanced fuel injector and an advanced segmented liner design. The full size combustor was evaluated at power conditions ranging from idle to maximum power. The effect of broad fuel properties was studied by evaluating the combustor with three different fuels. The fuels used were JP-5, a blend of Diesel Fuel Marine/Home Heating Oil, and a blend of Suntec C/Home Heating Oil. The fuel properties effect on the performance of the combustion in terms of pattern factor, liner temperatures, and exhaust emissions are documented.

  18. A single-cell imaging screen reveals multiple effects of secreted small molecules on bacteria

    PubMed Central

    Salje, Jeanne

    2014-01-01

    Bacteria cells exist in close proximity to other cells of both the same and different species. Bacteria secrete a large number of different chemical species, and the local concentrations of these compounds at the surfaces of nearby cells may reach very high levels. It is fascinating to imagine how individual cells might sense and respond to the complex mix of signals at their surface. However, it is difficult to measure exactly what the local environmental composition looks like, or what the effects of individual compounds on nearby cells are. Here, an electron microscopy imaging screen was designed that would detect morphological changes induced by secreted small molecules. This differs from conventional approaches by detecting structural changes in individual cells rather than gene expression or growth rate changes at the population level. For example, one of the changes detected here was an increase in outer membrane vesicle production, which does not necessarily correspond to a change in gene expression. This initial study focussed on Pseudomonas aeruginosa, Escherichia coli, and Burkholderia dolosa, and revealed an intriguing range of effects of secreted small molecules on cells both within and between species. PMID:24910069

  19. Effect of small nuclear ribonucleoprotein-associated polypeptide N on the proliferation of medulloblastoma cells

    PubMed Central

    JING, JUNJIE; ZHAO, YANG; WANG, CHENGFENG; ZHAO, QINGSHUANG; LIANG, QINCHUAN; WANG, SHOUSEN; MA, JIE

    2015-01-01

    Spliceosome mutations have been reported in various types of cancer and a number of antitumor drugs have been observed to tightly bind to spliceosome components. Small nuclear ribonucleoprotein-associated polypeptide N (SNRPN) is a small ribonuclear protein and is a key spliceosome constituent. However, the role of SNRPN in human medulloblastoma remains unknown. In the present study, the effect of SNRPN on cell growth was investigated in vitro using the Daoy human medulloblastoma cell line. Lentivirus (Lv)-mediated short hairpin (sh) RNA was used to silence SNRPN expression, which was verified by reverse transcription-quantitative polymerase chain reaction and western blotting. Cell proliferation was examined by MTT and colony formation assays. Knockdown of SNRPN markedly reduced the proliferation and colony formation ability of Daoy medulloblastoma cells. In addition, flow cytometric analysis revealed that the cell cycle distribution was altered when the Daoy cells were infected with Lv-shSNRPN. To the best of our knowledge, this is the first study to investigate the effect of SNRPN on cell proliferation in medulloblastoma. The results indicate that SNRPN may be a potential novel target for the development of pharmacological therapeutics in human medulloblastoma. PMID:25571951

  20. Effect of small nuclear ribonucleoprotein-associated polypeptide N on the proliferation of medulloblastoma cells.

    PubMed

    Jing, Junjie; Zhao, Yang; Wang, Chengfeng; Zhao, Qingshuang; Liang, Qinchuan; Wang, Shousen; Ma, Jie

    2015-05-01

    Spliceosome mutations have been reported in various types of cancer and a number of antitumor drugs have been observed to tightly bind to spliceosome components. Small nuclear ribonucleoprotein?associated polypeptide N (SNRPN) is a small ribonuclear protein and is a key spliceosome constituent. However, the role of SNRPN in human medulloblastoma remains unknown. In the present study, the effect of SNRPN on cell growth was investigated in vitro using the Daoy human medulloblastoma cell line. Lentivirus (Lv)-mediated short hairpin (sh) RNA was used to silence SNRPN expression, which was verified by reverse transcription?quantitative polymerase chain reaction and western blotting. Cell proliferation was examined by MTT and colony formation assays. Knockdown of SNRPN markedly reduced the proliferation and colony formation ability of Daoy medulloblastoma cells. In addition, flow cytometric analysis revealed that the cell cycle distribution was altered when the Daoy cells were infected with Lv?shSNRPN. To the best of our knowledge, this is the first study to investigate the effect of SNRPN on cell proliferation in medulloblastoma. The results indicate that SNRPN may be a potential novel target for the development of pharmacological therapeutics in human medulloblastoma. PMID:25571951

  1. The Effect of Variable End of Charge Battery Management on Small-Cell Batteries

    NASA Technical Reports Server (NTRS)

    Neubauer, Jeremy; Simmons, Nick; Bennetti, Andrea; Pearson, Chris; Reid, Concha

    2007-01-01

    ABSL Space Products is the world leading supplier of Lithium-ion batteries for space applications and has pioneered the use of small capacity COTS cells within large arrays. This small-cell approach has provided many benefits to space application designers through increased flexibility and reliability over more traditional battery designs. The ABSL 18650HC cell has been used in most ABSL space battery applications to date and has a recommended End Of Charge Voltage (EOCV) of 4.2V per cell. For all space applications using the ABSL 18650HC so far, this EOCV has been used at all stages of battery life from ground checkout to in orbit operations. ABSL and NASA have identified that, by using a lower EOCV for the same equivalent Depth Of Discharge (DOD), battery capacity fade could be reduced. The intention of this paper is to compare battery performance for systems with fixed and variable EOCV. In particular, the effect of employing the blanket value of 4.2V per cell versus utilizing a lower EOCV at Beginning Of Life (BOL) before gradually increasing it (as the effects of capacity fade drive the End Of Discharge Voltage closer to the acceptable system level minimum) is analyzed. Data is compared from ABSL in-house and NASA GRC tests that have been run under fixed and variable EOCV conditions. Differences in capacity fade are discussed and projections are made as to potential life extension capability by utilizing a variable EOCV strategy.

  2. Effects of hybrid synapses on the vibrational resonance in small-world neuronal networks

    NASA Astrophysics Data System (ADS)

    Yu, Haitao; Wang, Jiang; Sun, Jianbing; Yu, Haifeng

    2012-09-01

    We investigate the effect of vibrational resonance in small-world neuronal networks with hybrid chemical and electrical synapses. It is shown that, irrespective of the probability of chemical synapses, an optimal amplitude of high-frequency component of the signal can optimize the dynamical response of neuron populations to the low-frequency component, which encodes the information. This effect of vibrational resonance of neuronal systems depends extensively on the network structure and parameters, which determine the ability of neuronal networks to enhance the outreach of localized subthreshold low-frequency signal. In particular, chemical synaptic coupling is more efficient than the electrical coupling for the transmission of local input signal due to its selective coupling. Moreover, there exists an optimal small-world topology characterized by an optimal value of rewiring probability, warranting the largest peak value of the system response. Considering that two-frequency signals are ubiquity in brain dynamics, we expect the presented results could have important implications for signal processing in neuronal systems.

  3. EVOLVING EXPECTATIONS OF DAM REMOVAL OUTCOMES: DOWNSTREAM GEOMORPHIC EFFECTS FOLLOWING REMOVAL OF A SMALL, GRAVEL-FILLED DAM1

    E-print Network

    Tullos, Desiree

    EVOLVING EXPECTATIONS OF DAM REMOVAL OUTCOMES: DOWNSTREAM GEOMORPHIC EFFECTS FOLLOWING REMOVAL OF A SMALL, GRAVEL-FILLED DAM1 Kelly Kibler, Desiree Tullos, and Mathias Kondolf 2 ABSTRACT: Dam removal is a promising river restoration technique, particularly for the vast number of rivers impounded by small dams

  4. Effects of Surgically Implanted Transmitter Weights on Growth and Swimming Stamina of Small Adult Westslope Cutthroat Trout

    Microsoft Academic Search

    Alexander V. Zale; Carrie Brooke; William C. Fraser

    2005-01-01

    The generally accepted 2% ratio of transmitter weight to body weight constrains or precludes telemetry studies examining the timing and location of spawning of small adult westslope cutthroat trout Oncorhynchus clarkii lewisi in headwater streams. We empirically determined effects of surgically implanted dummy transmitters ranging in weight from 1 to 5 g on the swimming stamina and growth of small

  5. Barnacles, limpets and periwinkles: the effects of direct and indirect interactions on cyprid settlement and success

    NASA Astrophysics Data System (ADS)

    Holmes, Sebastian P.; Walker, Graham; van der Meer, Jaap

    2005-02-01

    Conventionally, direct interactions between species are considered to be the most important biological factors determining community composition, structure and stability. However, it has been suggested that the indirect interactions occurring between species may be as important. One area of ecology where the direct effects of one species on another have been well studied is in the rocky intertidal. Examination of the effect of the presence of P. vulgata (limpets) and L. littorea (periwinkles) on the settlement and development of S. balanoides (cyprids/barnacles), over a cyprid settlement season and some six months later, in four different treatments (limpets only, limpets and periwinkles combined, periwinkles only and control (no animals)) revealed the following: (1) that the presence of limpets increased cyprid settlement and recruitment success above treatments containing no limpets; (2) that cyprid settlement and success were greatest on the limpets-only treatment, followed by the limpets-and-periwinkles treatment, then by the control treatment and then by the periwinkles-only treatment; (3) that the initial effects observed in the treatments were reflected in the long-term community structure; (4) that the effects of the treatments were independent of variations in algal biomass between treatments, i.e. the effects were not indirectly mediated through a second species (host); (5) that cyprid mortality was greatest on the periwinkles-only treatment; (6) that the source of the effect of limpets on cyprid settlement appeared to originate indirectly through the action of their residual pedal mucus trails. It is concluded that periwinkles can affect the settlement and success of barnacles directly through biological disturbance (i.e. surface ablation). However, although limpets may have a direct negative effect on barnacle settlement and success, at low to medium densities, limpets can positively indirectly influence the cyprid settlement and success. This effect operates at a factor greater than that afforded by the direct negative effects of periwinkles in a mixed-species treatment. These results illustrate how the indirect effects of one species on another can have a more important structuring effect than those derived from direct effects alone.

  6. Hsp72 mediates TAp73? anti-apoptotic effects in small cell lung carcinoma cells

    PubMed Central

    Nyman, Ulrika; Muppani, Naveen Reddy; Zhivotovsky, Boris; Joseph, Bertrand

    2011-01-01

    Abstract The transcription factor p73, a member of the p53 family of proteins, is involved in the regulation of cell cycle progression and apoptosis. Due to alternative promoters and carboxy-terminal splicing, the P73 gene gives rise to a range of different isoforms. Interestingly, a particular increase in expression of the TAp73? isoform has been reported in various tumours. In addition, TAp73? has been shown to inhibit Bax activation and mitochondrial dysfunctions and thereby to confer small cell lung carcinoma (SCLC) cells resistance to drug-induced apoptosis. However, the precise mechanism by which TAp73? exerts its pro-survival effect is yet unclear. Here we report that TAp73?, but not TAp73?, regulates the expression of inducible Hsp72/HSPA1A. Hsp72 proved to be required for the survival effects of TAp73? as antisense knockdown of Hsp72 resulted in an abolishment of the anti-apoptotic effect of TAp73? in SCLC cells upon Etoposide treatment. Importantly, depletion of Hsp72 allowed activation of Bax, loss of mitochondrial membrane potential and lysosomal membrane permeabilization in SCLC cells even in the presence of TAp73?. Finally, we revealed that TAp73? counteracts the anti-apoptotic effect of TAp73? by preventing Hsp72 induction. Our results thus provide additional evidence for the potential oncogenic role of TAp73?, and extend the understanding of the mechanism for its anti-apoptotic effect. PMID:20807285

  7. Effect of small-scale fractures on flow and transport processes at Yucca Mountain, Nevada

    SciTech Connect

    Wu, Yu-Shu; Liu, H.H.; Bodvarsson, G.S.

    2002-12-05

    Although many conceptual models for fracture-matrix interaction have been evaluated for Yucca Mountain site-characterization studies, the most widely used model is currently based on the dual-permeability concept. It was chosen for use in site-characterization partially because it has proved to be capable of matching many types of field observed data. Another consideration is that net infiltration rates at the site are estimated to be very low (on the order of millimeters/year), or close to saturated matrix hydraulic conductivity. Recent field studies and tests, in particular, fracture mapping data, collected along the walls of the underground tunnels reveal that there exists a significantly large variety in fracture sizes from centimeters to tens of meters. There is a considerable amount of small-scale fractures that have not been considered in the previous modeling studies. Although the majority of these small fractures may not contribute much to global flow and transport through the fracture-matrix system, they may provide large amounts of storage pore space and allow for additional connection areas for well-connected, large-scale fractures and surrounding matrix blocks, which ultimately affect fracture-matrix interactions. However, the currently used dual-permeability model is unable to include the potentially important effect of small fractures. To overcome the limitations of the dual-permeability approach, we have developed a triple-continuum conceptual model to investigate the impact of small-scale fractures on flow and transport processes in fractured rocks. This new conceptual model subdivides fractures into two types: large-scale and small-scale. Large-scale fractures are those responsible for global connections; small-scale fractures are those that provide large-fracture storage space and enhance the local connections to the matrix system without contributing to global flow or transport. Because the triple-continuum model is composed of the rock matrix and two types of fractures, it can be regarded as an extension of the traditional dual-permeability model. Using a generalized triple-continuum approach, the model formulation uses three parallel sets of conservation equations to describe flow and transport processes at each location of the system, for the two-fracture and one-matrix systems, respectively. The proposed triple-continuum model has been implemented using both analytical and numerical approaches and applied to field problems at Yucca Mountain. First we apply the new conceptual model to estimate model-related fracture-matrix parameters using field observation data and inverse modeling approach. Then we incorporate the estimated parameters to perform 3-D site-scale flow and transport simulations with the current hydrogeological model of Yucca Mountain. The 3-D modeling results with the triple-continuum model indicate that small fractures have significant impact on radionuclide transport in the UZ system, while their effects on flow and heat transfer are insignificant.

  8. A single climate driver has direct and indirect effects on insect population dynamics.

    PubMed

    Boggs, Carol L; Inouye, David W

    2012-05-01

    Weather drives population dynamics directly, through effects on vital rates, or indirectly, through effects on the population's competitors, predators or prey and thence on vital rates. Indirect effects may include non-additive interactions with density dependence. Detection of climate drivers is critical to predicting climate change effects, but identification of potential drivers may depend on knowing the underlying mechanisms. For the butterfly Speyeria mormonia, one climate driver, snow melt date, has multiple effects on population growth. Snow melt date in year t has density-dependent indirect effects. Through frost effects, early snow melt decreases floral resources, thence per-capita nectar availability, which determines fecundity in the lab. Snow melt date in year t?+?1 has density-independent direct effects. These effects explain 84% of the variation in population growth rate. One climate parameter thus has multiple effects on the dynamics of a species with non-overlapping generations, with one effect not detectable without understanding the underlying mechanism. PMID:22414183

  9. Effects of inbreeding on fitness-related traits in a small isolated moose population

    PubMed Central

    Haanes, Hallvard; Markussen, Stine S; Herfindal, Ivar; Røed, Knut H; Solberg, Erling J; Heim, Morten; Midthjell, Liv; Sæther, Bernt-Erik

    2013-01-01

    Inbreeding can affect fitness-related traits at different life history stages and may interact with environmental variation to induce even larger effects. We used genetic parentage assignment based on 22 microsatellite loci to determine a 25 year long pedigree for a newly established island population of moose with 20–40 reproducing individuals annually. We used the pedigree to calculate individual inbreeding coefficients and examined for effects of individual inbreeding (f) and heterozygosity on fitness-related traits. We found negative effects of f on birth date, calf body mass and twinning rate. The relationship between f and calf body mass and twinning rate were found to be separate but weaker after accounting for birth date. We found no support for an inbreeding effect on the age-specific lifetime reproductive success of females. The influence of f on birth date was related to climatic conditions during the spring prior to birth, indicating that calves with a low f were born earlier after a cold spring than calves with high f. In years with a warm spring, calf f did not affect birth date. The results suggest that severe inbreeding in moose has both indirect effects on fitness through delayed birth and lower juvenile body mass, as well as separate direct effects, as there still was a significant relationship between f and twinning rate after accounting for birth date and body mass as calf. Consequently, severe inbreeding as found in the study population may have consequences for population growth and extinction risk. PMID:24324873

  10. Small molecule-directed specification of sclerotome-like chondroprogenitors and induction of a somitic chondrogenesis program from embryonic stem cells.

    PubMed

    Zhao, Jiangang; Li, Songhui; Trilok, Suprita; Tanaka, Makoto; Jokubaitis-Jameson, Vanta; Wang, Bei; Niwa, Hitoshi; Nakayama, Naoki

    2014-10-01

    Pluripotent embryonic stem cells (ESCs) generate rostral paraxial mesoderm-like progeny in 5-6?days of differentiation induced by Wnt3a and Noggin (Nog). We report that canonical Wnt signaling introduced either by forced expression of activated ?-catenin, or the small-molecule inhibitor of Gsk3, CHIR99021, satisfied the need for Wnt3a signaling, and that the small-molecule inhibitor of BMP type I receptors, LDN193189, was able to replace Nog. Mesodermal progeny generated using such small molecules were chondrogenic in vitro, and expressed trunk paraxial mesoderm markers such as Tcf15 and Meox1, and somite markers such as Uncx, but failed to express sclerotome markers such as Pax1. Induction of the osteochondrogenically committed sclerotome from somite requires sonic hedgehog and Nog. Consistently, Pax1 and Bapx1 expression was induced when the isolated paraxial mesodermal progeny were treated with SAG1 (a hedgehog receptor agonist) and LDN193189, then Sox9 expression was induced, leading to cartilaginous nodules and particles in the presence of BMP, indicative of chondrogenesis via sclerotome specification. By contrast, treatment with TGF? also supported chondrogenesis and stimulated Sox9 expression, but failed to induce the expression of Pax1 and Bapx1. On ectopic transplantation to immunocompromised mice, the cartilage particles developed under either condition became similarly mineralized and formed pieces of bone with marrow. Thus, the use of small molecules led to the effective generation from ESCs of paraxial mesodermal progeny, and to their further differentiation in vitro through sclerotome specification into growth plate-like chondrocytes, a mechanism resembling in vivo somitic chondrogenesis that is not recapitulated with TGF?. PMID:25294938

  11. Are self-directed work teams successful and effective tools for today`s organization?

    SciTech Connect

    Arnwine, A.D.

    1995-03-01

    The purpose of this research is to (1) show the effectiveness and success of self-directed work teams within the organization, (2) emphasize the importance of team building in the success of the team, and (3) assist organizations in building self-directed work teams. The researcher used a direct survey and studied the following team building techniques: (1) Is the team`s mission clearly defined to each team member? (2) Are the goals clearly defined and achievable by all team members? (3) Will empowerment (decision-making power) be given equally to all team members? (4) Will open and honest communication be allowed among team members? (5) Will each team member be respected and valued for his/her position on the team? (6) Are self-directed work teams effectively rewarded for accomplishments? (7) Have team members received adequate training to effectively complete their job tasks? Upon completion of the literature review and statistical data, and after analyzing the seven areas of team building techniques, it was determined three of the four teams were successful and effective. The only area of concern to the organization is that the participants felt they did not have true ownership of their teams; that is, team members were not given full empowerment. According to this study and the review of literature, full empowerment must be given to achieve successful and effective teams. If true empowerment is not given, the team will suffer in other areas of team building, and the organization will lose a valuable tool.

  12. The complex duration perception of emotional faces: effects of face direction

    PubMed Central

    Kliegl, Katrin M.; Limbrecht-Ecklundt, Kerstin; Dürr, Lea; Traue, Harald C.; Huckauf, Anke

    2015-01-01

    The perceived duration of emotional face stimuli strongly depends on the expressed emotion. But, emotional faces also differ regarding a number of other features like gaze, face direction, or sex. Usually, these features have been controlled by only using pictures of female models with straight gaze and face direction. Doi and Shinohara (2009) reported that an overestimation of angry faces could only be found when the model’s gaze was oriented toward the observer. We aimed at replicating this effect for face direction. Moreover, we explored the effect of face direction on the duration perception sad faces. Controlling for the sex of the face model and the participant, female and male participants rated the duration of neutral, angry, and sad face stimuli of both sexes photographed from different perspectives in a bisection task. In line with current findings, we report a significant overestimation of angry compared to neutral face stimuli that was modulated by face direction. Moreover, the perceived duration of sad face stimuli did not differ from that of neutral faces and was not influenced by face direction. Furthermore, we found that faces of the opposite sex appeared to last longer than those of the same sex. This outcome is discussed with regards to stimulus parameters like the induced arousal, social relevance, and an evolutionary context. PMID:25852589

  13. Direct and Indirect Effects of Climate Change on a Prairie Plant Community

    PubMed Central

    Adler, Peter B.; Leiker, James; Levine, Jonathan M.

    2009-01-01

    Background Climate change directly affects species by altering their physical environment and indirectly affects species by altering interspecific interactions such as predation and competition. Recent studies have shown that the indirect effects of climate change may amplify or counteract the direct effects. However, little is known about the the relative strength of direct and indirect effects or their potential to impact population persistence. Methodology/Principal Findings We studied the effects of altered precipitation and interspecific interactions on the low-density tiller growth rates and biomass production of three perennial grass species in a Kansas, USA mixed prairie. We transplanted plugs of each species into local neighborhoods of heterospecific competitors and then exposed the plugs to a factorial manipulation of growing season precipitation and neighbor removal. Precipitation treatments had significant direct effects on two of the three species. Interspecific competition also had strong effects, reducing low-density tiller growth rates and aboveground biomass production for all three species. In fact, in the presence of competitors, (log) tiller growth rates were close to or below zero for all three species. However, we found no convincing evidence that per capita competitive effects changed with precipitation, as shown by a lack of significant precipitation × competition interactions. Conclusions/Significance We found little evidence that altered precipitation will influence per capita competitive effects. However, based on species' very low growth rates in the presence of competitors in some precipitation treatments, interspecific interactions appear strong enough to affect the balance between population persistence and local extinction. Therefore, ecological forecasting models should include the effect of interspecific interactions on population growth, even if such interaction coefficients are treated as constants. PMID:19727390

  14. Direct and indirect effects of copper-contaminated sediments on the functions of model freshwater ecosystems.

    PubMed

    Gardham, Stephanie; Chariton, Anthony A; Hose, Grant C

    2015-01-01

    Copper is acutely toxic to, and directly affects, primary producers and decomposers, which are key players in essential processes such as the nutrient cycle in freshwater ecosystems. Even though the indirect effects of metals (for example effects due to changes in species interactions) may be more common than direct effects, little is known about the indirect effects of copper on primary producers and decomposers. The effects of copper on phytoplankton, macrophytes, periphyton and organic matter decomposition in an outdoor lentic mesocosm facility were assessed, and links between the responses examined. Copper directly decreased macrophyte growth, subsurface organic matter decomposition, and the potential for high phytoplankton Chlorophyll a concentrations. However, periphyton cover and organic matter decomposition on the surface of the sediment were stimulated by the presence of copper. These latter responses were attributed to indirect effects, due to a reduction in grazing pressure from snails, particularly Physa acuta, in the higher copper-contaminated mesocosms. This permitted the growth of periphyton and other heterotrophs, ultimately increasing decomposition at the sediment surface. The present study demonstrates the pronounced influence indirect effects may have on ecological function, findings that may not be observed in traditional laboratory studies (which utilize single species or simplistic communities). PMID:25261958

  15. Is Direct Access to Obstetricians/Gynecologists Effective at Improving Maternal Health Behaviors?

    PubMed Central

    Durrance, Christine Piette; Hankins, Scott

    2011-01-01

    Objective To examine the effects of state legislation mandating direct access to obstetricians and gynecologists (OB/GYNs) on maternal health behaviors and infant health outcomes. Data Sources 1992–2002 Natality Detail File; 1994–2002 Pregnancy Assessment and Monitoring Survey (PRAMS). Study Design Using variation in state policy over time, we use individual-level data from two sources to consider the effects of direct access legislation on prenatal care utilization, maternal health behaviors during pregnancy, and infant health outcomes. Principal Findings Our results suggest that there is little evidence that direct access laws are effective at improving prenatal care access or conferring benefits to mothers and infants. These results are consistent across two data sets, a variety of specifications, and specific subgroups of women who are most likely to be affected by direct access legislation. Conclusion We conclude that direct access to OB/GYNs is not related to improvements in maternal health behaviors or infant health outcomes. If policy makers are interested in reforms that improve maternal and infant health, we recommend a focus on alternative policies. PMID:21449955

  16. The Effect of Direct and Indirect Monitoring on Generosity Among Preschoolers

    PubMed Central

    Fujii, Takayuki; Takagishi, Haruto; Koizumi, Michiko; Okada, Hiroyuki

    2015-01-01

    The purpose of this study is to examine the effect of direct and indirect monitoring on generosity among five-year-old preschoolers and to reveal the primary motivation for their generosity. Forty-two preschoolers completed one-shot dictator games in Condition 1 while being monitored by the experimenter (the direct monitoring condition). In Condition 2, an image of staring eyes was displayed on the computer monitor (the indirect monitoring condition). In Condition 3, the computer monitor showed a picture of flowers (the non-monitoring condition). The results showed that while there was no difference between the mean levels of allocation in the indirect and non-monitoring conditions, the mean level of allocation in the direct monitoring condition was significantly higher than in the non-monitoring condition. These results showed that five-year-old preschoolers concerned with being monitored by, and receiving direct responses from, others tend to be more generous. PMID:25762347

  17. The effect of direct and indirect monitoring on generosity among preschoolers.

    PubMed

    Fujii, Takayuki; Takagishi, Haruto; Koizumi, Michiko; Okada, Hiroyuki

    2015-01-01

    The purpose of this study is to examine the effect of direct and indirect monitoring on generosity among five-year-old preschoolers and to reveal the primary motivation for their generosity. Forty-two preschoolers completed one-shot dictator games in Condition 1 while being monitored by the experimenter (the direct monitoring condition). In Condition 2, an image of staring eyes was displayed on the computer monitor (the indirect monitoring condition). In Condition 3, the computer monitor showed a picture of flowers (the non-monitoring condition). The results showed that while there was no difference between the mean levels of allocation in the indirect and non-monitoring conditions, the mean level of allocation in the direct monitoring condition was significantly higher than in the non-monitoring condition. These results showed that five-year-old preschoolers concerned with being monitored by, and receiving direct responses from, others tend to be more generous. PMID:25762347

  18. 76 FR 16703 - Small Business Jobs Act Tour: Selected Provisions Having an Effect on Government Contracting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-25

    ...small firms start or increase exporting. All small business owners...help provide. C. Expanding Exporting Opportunities for Small Business...sales and profit, and take advantage of increased demand for high-quality...services, should consider exporting. The Small Business...

  19. Effect of various structure directing agents on the physicochemical properties of the silica aerogels prepared at an ambient pressure

    NASA Astrophysics Data System (ADS)

    Sarawade, Pradip B.; Shao, Godlisten N.; Quang, Dang Viet; Kim, Hee Taik

    2013-12-01

    We studied the effects of various surfactants on the textural properties (BET surface area, pore size, and pore volume) of the silica aerogels prepared at an ambient pressure. A simple surface modification of silica gel prepared at an ambient pressure through hydrolysis and polycondensation of TEOS as a silica precursor was conducted using various structure directing agents. The treatment was found to induce a significant difference in the porosity of the silica aerogel. Highly porous silica aerogels with bimodal porous structures were prepared by modifying the surface of the silica wet-gel (alcogel) with trimethylchlorosilane (TMCS) in order to preserve its porosity. The samples were analyzed by small-angle X-ray scattering and nitrogen adsorption. In this work, a possible new type of highly porous hydrophobic silica aerogel with a bimodal porous structure is presented. A hydrophilic extremely porous (high surface area and large pore volume) silica aerogel was obtained by heating the as-synthesized hydrophobic silica aerogel at 400 °C for 1 h. There was a significant effect of structure directing agent on the textural properties, such as specific surface area, pore size distribution and cumulative pore volume of the silica aerogels.

  20. Photoacoustic Doppler Effect from Flowing Small Light-Absorbing Particles Hui Fang, Konstantin Maslov, and Lihong V. Wang*

    E-print Network

    Wang, Lihong

    Photoacoustic Doppler Effect from Flowing Small Light-Absorbing Particles Hui Fang, Konstantin.55.Kf, 87.80.ÿy Laser flowmetry and acoustic flowmetry based on the Doppler effect [1] have become physical phenomenon--the photoacoustic Doppler (PAD) effect from moving particles--and its application