Science.gov

Sample records for small direct effect

  1. Direct and Propagated Effects of Small Molecules on Protein–Protein Interaction Networks

    PubMed Central

    Cesa, Laura C.; Mapp, Anna K.; Gestwicki, Jason E.

    2015-01-01

    Networks of protein–protein interactions (PPIs) link all aspects of cellular biology. Dysfunction in the assembly or dynamics of PPI networks is a hallmark of human disease, and as such, there is growing interest in the discovery of small molecules that either promote or inhibit PPIs. PPIs were once considered undruggable because of their relatively large buried surface areas and difficult topologies. Despite these challenges, recent advances in chemical screening methodologies, combined with improvements in structural and computational biology have made some of these targets more tractable. In this review, we highlight developments that have opened the door to potent chemical modulators. We focus on how allostery is being used to produce surprisingly robust changes in PPIs, even for the most challenging targets. We also discuss how interfering with one PPI can propagate changes through the broader web of interactions. Through this analysis, it is becoming clear that a combination of direct and propagated effects on PPI networks is ultimately how small molecules re-shape biology. PMID:26380257

  2. Effect of Stepwise Pressure Change on Porosity Evolution during Directional Solidification in Small Cylindrical Channels

    NASA Technical Reports Server (NTRS)

    Grugel, R.N.; Lee, C.P.; Cox, M.C.; Blandford, B.T.; Anilkumar, A.V.

    2008-01-01

    Controlled directional solidification experiments were performed in capillary channels, using nitrogen-saturated succinonitrile, to examine the effect of an in-situ stepwise processing pressure increase on an isolated pore evolution. Two experiments were performed using different processing pressure input profiles. The results indicate that a processing pressure increase has a transient effect on pore growth geometry characterized by an initial phase of decreasing pore diameter, followed by a recovery phase of increasing pore diameter. The experimental results also show that processing pressure can be used as a control parameter to either increase or terminate porosity formation. A theoretical model is introduced which indicates that the pore formation process is limited by the diffusion of solute-gas through the melt, and that the observed response toa pressure increase is attributed to the re-equilibration of solute concentration in the melt associated with the increased melt pressure.

  3. Small-signal modeling with direct parameter extraction for impact ionization effect in high-electron-mobility transistors

    NASA Astrophysics Data System (ADS)

    Guan, He; Lv, Hongliang; Guo, Hui; Zhang, Yuming

    2015-11-01

    Impact ionization affects the radio-frequency (RF) behavior of high-electron-mobility transistors (HEMTs), which have narrow-bandgap semiconductor channels, and this necessitates complex parameter extraction procedures for HEMT modeling. In this paper, an enhanced small-signal equivalent circuit model is developed to investigate the impact ionization, and an improved method is presented in detail for direct extraction of intrinsic parameters using two-step measurements in low-frequency and high-frequency regimes. The practicability of the enhanced model and the proposed direct parameter extraction method are verified by comparing the simulated S-parameters with published experimental data from an InAs/AlSb HEMT operating over a wide frequency range. The results demonstrate that the enhanced model with optimal intrinsic parameter values that were obtained by the direct extraction approach can effectively characterize the effects of impact ionization on the RF performance of HEMTs.

  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. Antiviral Immunity Directed by Small RNAs

    PubMed Central

    Ding, Shou-Wei; Voinnet, Olivier

    2009-01-01

    Plants and invertebrates can protect themselves from viral infection through RNA silencing. This antiviral immunity involves production of virus-derived small interfering RNAs (viRNAs) and results in specific silencing of viruses by viRNA-guided effector complexes. The proteins required for viRNA production as well as several key downstream components of the antiviral immunity pathway have been identified in plants, flies, and worms. Meanwhile, viral mechanisms to suppress this small RNA-directed immunity by viruses are being elucidated, thereby illuminating an ongoing molecular arms race that likely impacts the evolution of both viral and host genomes. PMID:17693253

  6. 75 FR 15756 - Small Business Innovation Research Program Policy Directive

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ...to the Small Business Innovation Research (SBIR) Program...Directive; Small Business Innovation Research Program To...Directors, Small Business Innovation Research (SBIR) Program...with the issuance and management of funding...

  7. Direct Modulation of Small GTPase Activity and Function.

    PubMed

    Cromm, Philipp M; Spiegel, Jochen; Grossmann, Tom N; Waldmann, Herbert

    2015-11-01

    Small GTPases are a family of GDP-/GTP-binding proteins that serve as biomolecular switches inside cells to control a variety of essential cellular processes. Aberrant function and regulation of small GTPases is associated with a variety of human diseases, thus rendering these proteins highly interesting targets in drug discovery. However, this class of proteins has been considered "undruggable", as intensive decade-long efforts did not yield clinically relevant direct modulators of small GTPases. Recently, the targeting of small GTPases has gained fresh impetus through the discovery of novel transient cavities on the protein surfaces and the application of new targeting strategies. Besides Ras proteins, other small GTPases have attracted increased attention since improved biological insight in combination with novel targeting strategies identified them as promising targets in drug discovery. This Review gives an overview of relevant aspects of the superfamily of small GTPases and summarizes recent progress and perspectives for the direct modulation of these challenging targets. PMID:26470842

  8. 75 FR 15756 - Small Business Innovation Research Program Policy Directive

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... Phase II award threshold amount from $750,000 to $1,000,000 (FR 48004). Congress established the current... (67 FR 6008, Sept. 24, 2002). SBA has determined that to restore the average economic value of the... RIN 3244-AF61 Small Business Innovation Research Program Policy Directive AGENCY: U.S. Small...

  9. 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,…

  10. 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…

  11. 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.

  12. EFFECTIVE FILTRATION METHODS FOR SMALL WATER SUPPLIES

    EPA Science Inventory

    A 2-year study was conducted of various simple water filtration systems potentially appropriate for high-quality surface waters serving small systems. A slow sand filter without coagulant and a direct, rapid filter with coagulant were operated in parallel. Direct filtration with ...

  13. An Automated Directed Spectral Search Methodology for Small Target Detection

    NASA Astrophysics Data System (ADS)

    Grossman, Stanley I.

    Much of the current efforts in remote sensing tackle macro-level problems such as determining the extent of wheat in a field, the general health of vegetation or the extent of mineral deposits in an area. However, for many of the remaining remote sensing challenges being studied currently, such as border protection, drug smuggling, treaty verification, and the war on terror, most targets are very small in nature - a vehicle or even a person. While in typical macro-level problems the objective vegetation is in the scene, for small target detection problems it is not usually known if the desired small target even exists in the scene, never mind finding it in abundance. The ability to find specific small targets, such as vehicles, typifies this problem. Complicating the analyst's life, the growing number of available sensors is generating mountains of imagery outstripping the analysts' ability to visually peruse them. This work presents the important factors influencing spectral exploitation using multispectral data and suggests a different approach to small target detection. The methodology of directed search is presented, including the use of scene-modeled spectral libraries, various search algorithms, and traditional statistical and ROC curve analysis. The work suggests a new metric to calibrate analysis labeled the analytic sweet spot as well as an estimation method for identifying the sweet spot threshold for an image. It also suggests a new visualization aid for highlighting the target in its entirety called nearest neighbor inflation (NNI). It brings these all together to propose that these additions to the target detection arena allow for the construction of a fully automated target detection scheme. This dissertation next details experiments to support the hypothesis that the optimum detection threshold is the analytic sweet spot and that the estimation method adequately predicts it. Experimental results and analysis are presented for the proposed directed search techniques of spectral image based small target detection. It offers evidence of the functionality of the NNI visualization and also provides evidence that the increased spectral dimensionality of the 8-band Worldview-2 datasets provides noteworthy improvement in results over traditional 4-band multispectral datasets. The final experiment presents the results from a prototype fully automated target detection scheme in support of the overarching premise. This work establishes the analytic sweet spot as the optimum threshold defined as the point where error detection rate curves -- false detections vs. missing detections -- cross. At this point the errors are minimized while the detection rate is maximized. It then demonstrates that taking the first moment statistic of the histogram of calculated target detection values from a detection search with test threshold set arbitrarily high will estimate the analytic sweet spot for that image. It also demonstrates that directed search techniques -- when utilized with appropriate scene-specific modeled signatures and atmospheric compensations -- perform at least as well as in-scene search techniques 88% of the time and grossly under-performing only 11% of the time; the in-scene only performs as well or better 50% of the time. It further demonstrates the clear advantage increased multispectral dimensionality brings to detection searches improving performance in 50% of the cases while performing at least as well 72% of the time. Lastly, it presents evidence that a fully automated prototype performs as anticipated laying the groundwork for further research into fully automated processes for small target detection.

  14. 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...

  15. Small-RNA asymmetry is directly driven by mammalian Argonautes.

    PubMed

    Suzuki, Hiroshi I; Katsura, Akihiro; Yasuda, Takahiko; Ueno, Toshihide; Mano, Hiroyuki; Sugimoto, Koichi; Miyazono, Kohei

    2015-07-01

    Asymmetric selection of single-stranded guide RNAs from double-stranded RNA precursors is crucial in RNA silencing-mediated gene regulation. However, the precise mechanisms of small-RNA asymmetry are unclear, especially because asymmetric selection can still occur when the putative asymmetry sensors Drosophila R2D2 and mammalian Dicer are depleted. Here we report a direct contribution of mammalian Argonaute 2 (Ago2) to microRNA (miRNA) asymmetry. Ago2 selects strands with 5'-uridine or 5'-adenosine and thermodynamically unstable 5' ends in parallel through its two sensor regions, which contact the 5' nucleobases and 5'-phosphates of prospective guide strands. Hence, miRNA asymmetry shows superposed patterns reflecting 5'-end nucleotide identity ('digital' pattern) and thermodynamic stability ('analog' pattern). Furthermore, we demonstrate that cancer-associated miRNA variations reprogram asymmetric selection. Finally, our study presents a model of this universal principle, to aid in comprehensive understanding of miRNA function and development of new RNA-silencing therapies in precision medicine. PMID:26098316

  16. Rupture directivity of small earthquakes at Parkfield Deborah L. Kane,1,2

    E-print Network

    Shearer, Peter

    Rupture directivity of small earthquakes at Parkfield Deborah L. Kane,1,2 Peter M. Shearer,1 directivity model but suggest that directivity is likely due to several contributing factors. Citation: Kane

  17. 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…

  18. 77 FR 46855 - Small Business Technology Transfer Program Policy Directive

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ... award process, STTR Program administration, and fraud, waste and abuse and SBA has addressed these..., but does not fit into any of the other databases. D. Fraud, Waste and Abuse Finally, this Policy Directive incorporates several amendments relating to fraud, waste and abuse, such as: Requiring...

  19. Oligosaccharide-assisted direct immunosensing of small molecules.

    PubMed

    Kobayashi, Norihiro; Oyama, Hiroyuki; Suzuki, Iwao; Kato, Yoshinori; Umemura, Takeo; Goto, Junichi

    2010-06-01

    "Sandwich-type" noncompetitive (immunometric) assays allow for high-sensitivity high-throughput macromolecule sensing and determination but cannot be used on small molecules (haptens). Here, we isolated single-chain Fv fragments from a phage-display library, which bound to complexes of particular haptens (vitamin D and A derivatives) with immobilized beta-cyclodextrin or beta-maltosyl residues, and formed ternary complexes. These scFvs enabled novel "semisandwich-type" immunometric assays of haptens with nanomole-range sensitivities. PMID:20459059

  20. Direct connections assist neurons to detect correlation in small amplitude noises

    PubMed Central

    Bolhasani, E.; Azizi, Y.; Valizadeh, A.

    2013-01-01

    We address a question on the effect of common stochastic inputs on the correlation of the spike trains of two neurons when they are coupled through direct connections. We show that the change in the correlation of small amplitude stochastic inputs can be better detected when the neurons are connected by direct excitatory couplings. Depending on whether intrinsic firing rate of the neurons is identical or slightly different, symmetric or asymmetric connections can increase the sensitivity of the system to the input correlation by changing the mean slope of the correlation transfer function over a given range of input correlation. In either case, there is also an optimum value for synaptic strength which maximizes the sensitivity of the system to the changes in input correlation. PMID:23966940

  1. Note: Direct piezoelectric effect microscopy.

    PubMed

    Mori, T J A; Stamenov, P; Dorneles, L S

    2015-07-01

    An alternative method for investigating piezoelectric surfaces is suggested, exploiting the direct piezoeffect. The technique relies on acoustic (ultrasonic) excitation of the imaged surface and mapping of the resulting oscillatory electric potential. The main advantages arise from the spatial resolution of the conductive scanning probe microscopy in combination with the relatively large magnitude of the forward piezo signal Upf, which can be of the order of tens of mV even for non-ferroelectric piezoelectric materials. The potency of this experimental strategy is illustrated with measurements on well-crystallized quartz surfaces, where Upf ? 50 mV, for a piezoelectric coefficient of d33 = - 2.27? × ?10(-12) m/V, and applied stress of about T3 ? 5.7 kPa. PMID:26233416

  2. Note: Direct piezoelectric effect microscopy

    NASA Astrophysics Data System (ADS)

    Mori, T. J. A.; Stamenov, P.; Dorneles, L. S.

    2015-07-01

    An alternative method for investigating piezoelectric surfaces is suggested, exploiting the direct piezoeffect. The technique relies on acoustic (ultrasonic) excitation of the imaged surface and mapping of the resulting oscillatory electric potential. The main advantages arise from the spatial resolution of the conductive scanning probe microscopy in combination with the relatively large magnitude of the forward piezo signal Upf, which can be of the order of tens of mV even for non-ferroelectric piezoelectric materials. The potency of this experimental strategy is illustrated with measurements on well-crystallized quartz surfaces, where Upf ˜ 50 mV, for a piezoelectric coefficient of d33 = - 2.27 × 10-12 m/V, and applied stress of about T3 ˜ 5.7 kPa.

  3. Power-Efficient Directional Wireless Communication on Small Form-Factor Mobile Devices

    E-print Network

    Zhong, Lin

    in this work: · We present BeamSwitch, a design that realizes directional communication on mobile devicesPower-Efficient Directional Wireless Communication on Small Form-Factor Mobile Devices Ardalan to be power-hungry for mobile devices. A key reason is that devices radiate power in all directions and much

  4. 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…

  5. 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.

  6. Power generation performance of direct flame fuel cell (DFFC) impinged by small jet flames

    NASA Astrophysics Data System (ADS)

    Nakamura, Yuji; Endo, Shota

    2015-10-01

    This paper investigated the effect of cell temperature and product species concentration induced by a small jet flame on the power generation performance of a direct flame fuel cell (DFFC). The cell is placed above the small-scale jet flame and the heated product’s gases are impinged toward it. This system is considered to be the simplest and smallest unit of such power generation devices to have been developed. Methane is used as fuel and an equivalence ratio (? ) of the mixture (with oxygen) and the distance between the cell and the burner surface (d) are considered as the experimental parameters. It turns out that open circuit voltage increases linearly with the increase of temperature in a wide range of equivalence ratios. However, it increases drastically to the point at which the equivalence ratio becomes small enough (? ?????2.0 in the present study) within the specific distance range to bring about the appearance of an inner flame. This could provide sufficient heat and oxygen for the anode, contributing to the generation of the cell’s high electric potential. It is also noted that the appearance of the inner flame does not promise to better the performance unless the preferred conditions (high temperature, low oxygen, rich fuel) near the cell are achieved. The Nernst equation works well for predicting the open circuit voltage under the conditions studied. Systematic design of the entire power generation system is preferable when a miniaturized power generation system is considered by applying DFFC.

  7. Process Evaluation Results from the Healthy Directions-Small Business Study

    ERIC Educational Resources Information Center

    Hunt, Mary K.; Barbeau, Elizabeth M.; Lederman, Ruth; Stoddard, Anne M.; Chetkovich, Carol; Goldman, Roberta; Wallace, Lorraine; Sorensen, Glorian

    2007-01-01

    The Healthy Directions-Small Business randomized, controlled study aimed to reduce cancer risk among multiethnic workers in small manufacturing businesses by increasing fruit and vegetable consumption, physical activity, and daily multivitamin in take and decreasing consumption of red meat. The intervention incorporated participatory strategies…

  8. 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.

  9. Laser direct synthesis of silicon nanowire field effect transistors.

    PubMed

    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. PMID:25590692

  10. Optimising thermal efficiency of direct contact membrane distillation by brine recycling for small-scale seawater desalination

    E-print Network

    Optimising thermal efficiency of direct contact membrane distillation by brine recycling for small Keywords: Direct contact membrane distillation (DCMD) Seawater desalination Thermal efficiency Brine during direct contact membrane distillation (DCMD) of seawater was investigated. By returning the hot

  11. Ising model on directed small-world Voronoi Delaunay random lattices

    NASA Astrophysics Data System (ADS)

    Sousa, Ediones M.; Lima, F. W. S.

    2013-12-01

    We investigate the critical properties of the Ising model in two dimensions on directed small-world lattice with quenched connectivity disorder. The disordered system is simulated by applying the Monte Carlo update heat bath algorithm. We calculate the critical temperature, as well as the critical exponents ?/ ?, ?/ ?, and 1/ ? for several values of the rewiring probability p . We find that this disorder system does not belong to the same universality class as the regular two-dimensional ferromagnetic model. The Ising model on directed small-world lattices presents in fact a second-order phase transition with new critical exponents which do not depend on p (0 < p < 1), but are identical to the exponents of the Ising model and the spin-1 Blume-Capel model on directed small-world network.

  12. Direct detection of the asteroidal YORP effect.

    PubMed

    Lowry, Stephen C; Fitzsimmons, Alan; Pravec, Petr; Vokrouhlicky, David; Boehnhardt, Hermann; Taylor, Patrick A; Margot, Jean-Luc; Galád, Adrian; Irwin, Mike; Irwin, Jonathan; Kusnirák, Peter

    2007-04-13

    The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is believed to alter the spin states of small bodies in the solar system. However, evidence for the effect has so far been indirect. We report precise optical photometric observations of a small near-Earth asteroid, (54509) 2000 PH5, acquired over 4 years. We found that the asteroid has been continuously increasing its rotation rate omega over this period by domega/dt = 2.0 (+/-0.2) x 10(-4) degrees per day squared. We simulated the asteroid's close Earth approaches from 2001 to 2005, showing that gravitational torques cannot explain the observed spin rate increase. Dynamical simulations suggest that 2000 PH5 may reach a rotation period of approximately 20 seconds toward the end of its expected lifetime. PMID:17347414

  13. Effective field theory for the small-x evolution

    E-print Network

    Ian Balitsky

    2001-05-31

    The small-x behavior of structure functions in the saturation region is determined by the non-linear generalization of the BFKL equation. I suggest the effective field theory for the small-x evolution which solves formally this equation. The result is the 2+1 functional integral for the structure functions at small x.

  14. 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.

  15. Vegetated treatment area effectiveness at reducing nutrient runoff from small swine operations in central Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous modeling and field studies have evaluated the effectiveness of vegetative treatment systems in treating runoff from animal feeding operations; however, none have evaluated the effectiveness of vegetative treatment areas (VTA’s) receiving direct runoff from small swine operations during natu...

  16. 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.

  17. Thermal effects on chaotic directed transport

    E-print Network

    Gabriel G. Carlo; Maria E. Spina

    2008-12-03

    We study a chaotic ratchet system under the influence of a thermal environment. By direct integration of the Lindblad equation we are able to analyze its behavior for a wide range of couplings with the environment, and for different finite temperatures. We observe that the enhancement of the classical and quantum currents due to temperature depend strongly on the specific properties of the system. This makes difficult to extract universal behaviors. We have also found that there is an analogy between the effects of the classical thermal noise and those of the finite $\\hbar$ size. These results open many possibilities for their testing and implementation in kicked BECs and cold atoms experiments.

  18. Direct Measurement of the Chudakov Effect

    SciTech Connect

    Virkus, T.; Thomsen, H. D.; Uggerhoej, E.; Uggerhoej, U. I.; Ballestrero, S.; Sona, P.; Mangiarotti, A.; Ketel, T. J.; Dizdar, A.; Kartal, S.; Pagliarone, C.

    2008-04-25

    Experimental results for the restricted energy loss of pairs created from 1-178 GeV photons in a thin Au target and subsequently passing a CCD detector are presented. It is shown that pairs--when detected close to the creation vertex--suffer a reduced energy loss due to the internal screening of the charges constituting the pair. Furthermore, the ability to measure directly the energy of the pair by calorimetry enables a comparison with theory as a function of energy. The observed phenomenon is in good qualitative agreement with general expectations from the Chudakov effect but indicates a quantitative disagreement with either of two mutually disagreeing theories.

  19. A complex task? Direct modulation of transcription factors with small molecules

    PubMed Central

    Koehler, Angela N.

    2010-01-01

    Transcription factors with aberrant activity in disease are promising yet untested targets for therapeutic development, particularly in oncology. Directly inhibiting or activating the function of a transcription factor requires specific disruption or recruitment of protein-protein or protein-DNA interactions. The discovery or design of small molecules that specifically modulate these interactions has thus far proven to be a significant challenge and the protein class is often perceived to be ‘undruggable.’ This review will summarize recent progress in the development of small-molecule probes of transcription factors and provide evidence to challenge the notion that this important protein class is chemically intractable. PMID:20395165

  20. 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

  1. 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

  2. Duty cycle effects on small engine emissions

    SciTech Connect

    Gabele, P.

    1998-12-31

    The paper presents emissions data obtained from seven lawn mower engines that were tested using three duty cycles: a six mode steady-state test, a quasi-steady-state test, and a transient test. A comparison of emissions from the three duty cycles is made for non-methane organic gases, carbon monoxide, nitrogen oxides, detailed hydrocarbons (percent of total organic emissions that are paraffin, olefin, aromatic, or acetylene), and toxic compounds (benzene, 1,3-butadiene, formaldehyde, and acetaldehyde). Differences in ozone potential are also determined and reported for each duty cycle. The study includes both regulated and unregulated (not certified to any emission standard) test engines that have a wide range of emission rates. Results indicate that regulated emission rate differences due to duty cycle are fairly small (less than ten percent on the average). For over half of the regulated emissions data, there is no significant difference in emission rates between data obtained using the steady-state and the transient duty cycle. Emission comparisons are even better between the quasi-steady-state and steady-state data. Ozone potential and toxic emissions are ten to twenty percent higher with the transient test cycle and organic composition appears unaffected by duty cycle selection.

  3. Duty cycle effects on small engine emissions

    SciTech Connect

    Gabele, P.

    1998-06-01

    The paper presents emissions data obtained from seven lawn mower engines that were tested using three duty cycles: a six mode steady-state test, a quasi-steady-state test, and a transient test. A comparison of emissions from the three duty cycles is made for non-methane organic gases, carbon monoxide, nitrogen oxides, detailed hydrocarbons (percent of total organic emissions that are paraffin, olefin, aromatic, or acetylene), and toxic compounds (benzene, 1,3-butadiene, formaldehyde, and acetaldehyde). Dufferences in ozone potential are also determined and reported for each duty cycle. The study includes both regulated and unregulated (not certified to any emission standard) test engines that have a wide range of emission rates. Results indicate that regulated emission rate differences due to duty cycle are fairly small (less than ten percent on the average). For over half of the regulated emission data, there is no significant difference in emission rates between data obtained using the steady-state and transient duty cycle. Emission comparisons are even better between the quasi-steady-state and steady-state data.

  4. FY 2011 4th Quarter Metric: Estimate of Future Aerosol Direct and Indirect Effects

    SciTech Connect

    Koch, D

    2011-09-21

    The global and annual mean aerosol direct and indirect effects, relative to 1850 conditions, estimated from CESM simulations are 0.02 W m-2 and -0.39 W m-2, respectively, for emissions in year 2100 under the IPCC RCP8.5 scenario. The indirect effect is much smaller than that for 2000 emissions because of much smaller SO2 emissions in 2100; the direct effects are small due to compensation between warming by black carbon and cooling by sulfate.

  5. A Small Molecule Inhibits Akt through Direct Binding to Akt and Preventing Akt Membrane Translocation*

    PubMed Central

    Kim, Donghwa; Sun, Mei; He, Lili; Zhou, Qing-Hua; Chen, Jun; Sun, Xia-Meng; Bepler, Gerold; Sebti, Said M.; Cheng, Jin Q.

    2010-01-01

    The Akt pathway is frequently hyperactivated in human cancer and functions as a cardinal nodal point for transducing extracellular and intracellular oncogenic signals and, thus, presents an exciting target for molecular therapeutics. Here we report the identification of a small molecule Akt/protein kinase B inhibitor, API-1. Although API-1 is neither an ATP competitor nor substrate mimetic, it binds to pleckstrin homology domain of Akt and blocks Akt membrane translocation. Furthermore, API-1 treatment of cancer cells results in inhibition of the kinase activities and phosphorylation levels of the three members of the Akt family. In contrast, API-1 had no effects on the activities of the upstream Akt activators, phosphatidylinositol 3-kinase, phosphatidylinositol-dependent kinase-1, and mTORC2. Notably, the kinase activity and phosphorylation (e.g. Thr(P)308 and Ser(P)473) levels of constitutively active Akt, including a naturally occurring mutant AKT1-E17K, were inhibited by API-1. API-1 is selective for Akt and does not inhibit the activation of protein kinase C, serum and glucocorticoid-inducible kinase, protein kinase A, STAT3, ERK1/2, or JNK. The inhibition of Akt by API-1 resulted in induction of cell growth arrest and apoptosis selectively in human cancer cells that harbor constitutively activated Akt. Furthermore, API-1 inhibited tumor growth in nude mice of human cancer cells in which Akt is elevated but not of those cancer cells in which it is not. These data indicate that API-1 directly inhibits Akt through binding to the Akt pleckstrin homology domain and blocking Akt membrane translocation and that API-1 has anti-tumor activity in vitro and in vivo and could be a potential anti-cancer agent for patients whose tumors express hyperactivated Akt. PMID:20068047

  6. Capturing the complexity of first opinion small animal consultations using direct observation

    PubMed Central

    Robinson, N. J.; Brennan, M. L.; Cobb, M.; Dean, R. S.

    2015-01-01

    Various different methods are currently being used to capture data from small animal consultations. The aim of this study was to develop a tool to record detailed data from consultations by direct observation. A second aim was to investigate the complexity of the consultation by examining the number of problems discussed per patient. A data collection tool was developed and used during direct observation of small animal consultations in eight practices. Data were recorded on consultation type, patient signalment and number of problems discussed. During 16?weeks of data collection, 1901 patients were presented. Up to eight problems were discussed for some patients; more problems were discussed during preventive medicine consultations than during first consultations (P<0.001) or revisits (P<0.001). Fewer problems were discussed for rabbits than cats (P<0.001) or dogs (P<0.001). Age was positively correlated with discussion of specific health problems and negatively correlated with discussion of preventive medicine. Consultations are complex with multiple problems frequently discussed, suggesting comorbidity may be common. Future research utilising practice data should consider how much of this complexity needs to be captured, and use appropriate methods accordingly. The findings here have implications for directing research and education as well as application in veterinary practice. PMID:25262057

  7. Effects of Ocular Optics on Perceived Visual Direction and Depth

    NASA Astrophysics Data System (ADS)

    Ye, Ming

    Most studies of human retinal image quality have specifically addressed the issues of image contrast, few have examined the problem of image location. However, one of the most impressive properties of human vision involves the location of objects. We are able to identify object location with great accuracy (less than 5 arcsec). The sensitivity we exhibit for image location indicates that any optical errors, such as refractive error, ocular aberrations, pupil decentration, etc., may have noticeable effects on perceived visual direction and distance of objects. The most easily observed effects of these optical factors is a binocular depth illusion called chromostereopsis in which equidistance colored objects appear to lie at the different distances. This dissertation covers a series of theoretical and experimental studies that examined the effects of ocular optics on perceived monocular visual direction and binocular chromostereopsis. Theoretical studies included development of an adequate eye model for predicting chromatic aberration, a major ocular aberration, using geometric optics. Also, a wave optical analysis is used to model the effects of defocus, optical aberrations, Stiles-Crawford effect (SCE) and pupil location on retinal image profiles. Experimental studies used psychophysical methods such as monocular vernier alignment tests, binocular stereoscopic tests, etc. This dissertation concludes: (1) With a decentered large pupil, the SCE reduces defocused image shifts compare to an eye without the SCE. (2) The blurred image location can be predicted by the centroid of the image profile. (3) Chromostereopsis with small pupils can be precisely accounted for by the interocular difference in monocular transverse chromatic aberration. (4) The SCE also plays an important role in the effect of pupil size on chromostereopsis. The reduction of chromostereopsis with large pupils can be accurately predicted by the interocular difference in monocular chromatic diplopia which is also reduced with large pupils. This supports the hypothesis that the effect of pupil size on chromostereopsis is due to monocular mechanisms.

  8. 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 ...

  9. The effect of very small air gaps on small field dosimetry

    NASA Astrophysics Data System (ADS)

    Charles, P. H.; Crowe, S. B.; Kairn, T.; Kenny, J.; Lehmann, J.; Lye, J.; Dunn, L.; Hill, B.; Knight, R. T.; Langton, C. M.; Trapp, J. V.

    2012-11-01

    The purpose of this study was to investigate the effect of very small air gaps (less than 1 mm) on the dosimetry of small photon fields used for stereotactic treatments. Measurements were performed with optically stimulated luminescent dosimeters (OSLDs) for 6 MV photons on a Varian 21iX linear accelerator with a Brainlab µMLC attachment for square field sizes down to 6 mm × 6 mm. Monte Carlo simulations were performed using EGSnrc C++ user code cavity. It was found that the Monte Carlo model used in this study accurately simulated the OSLD measurements on the linear accelerator. For the 6 mm field size, the 0.5 mm air gap upstream to the active area of the OSLD caused a 5.3% dose reduction relative to a Monte Carlo simulation with no air gap. A hypothetical 0.2 mm air gap caused a dose reduction >2%, emphasizing the fact that even the tiniest air gaps can cause a large reduction in measured dose. The negligible effect on an 18 mm field size illustrated that the electronic disequilibrium caused by such small air gaps only affects the dosimetry of the very small fields. When performing small field dosimetry, care must be taken to avoid any air gaps, as can be often present when inserting detectors into solid phantoms. It is recommended that very small field dosimetry is performed in liquid water. When using small photon fields, sub-millimetre air gaps can also affect patient dosimetry if they cannot be spatially resolved on a CT scan. However the effect on the patient is debatable as the dose reduction caused by a 1 mm air gap, starting out at 19% in the first 0.1 mm behind the air gap, decreases to <5% after just 2 mm, and electronic equilibrium is fully re-established after just 5 mm.

  10. Direct Conversion of Normal and Alzheimer's Disease Human Fibroblasts into Neuronal Cells by Small Molecules.

    PubMed

    Hu, Wenxiang; Qiu, Binlong; Guan, Wuqiang; Wang, Qinying; Wang, Min; Li, Wei; Gao, Longfei; Shen, Lu; Huang, Yin; Xie, Gangcai; Zhao, Hanzhi; Jin, Ying; Tang, Beisha; Yu, Yongchun; Zhao, Jian; Pei, Gang

    2015-08-01

    Neuronal conversion from human fibroblasts can be induced by lineage-specific transcription factors; however, the introduction of ectopic genes limits the therapeutic applications of such induced neurons (iNs). Here, we report that human fibroblasts can be directly converted into neuronal cells by a chemical cocktail of seven small molecules, bypassing a neural progenitor stage. These human chemical-induced neuronal cells (hciNs) resembled hiPSC-derived neurons and human iNs (hiNs) with respect to morphology, gene expression profiles, and electrophysiological properties. This approach was further applied to generate hciNs from familial Alzheimer's disease patients. Taken together, our transgene-free and chemical-only approach for direct reprogramming of human fibroblasts into neurons provides an alternative strategy for modeling neurological diseases and for regenerative medicine. PMID:26253202

  11. 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.

  12. 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.

  13. 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.

  14. Small-angle scattering gives direct structural information about a membrane protein inside a lipid environment.

    PubMed

    Kynde, Søren A R; Skar-Gislinge, Nicholas; Pedersen, Martin Cramer; Midtgaard, Søren Roi; Simonsen, Jens Baek; Schweins, Ralf; Mortensen, Kell; Arleth, Lise

    2014-02-01

    Monomeric bacteriorhodopsin (bR) reconstituted into POPC/POPG-containing nanodiscs was investigated by combined small-angle neutron and X-ray scattering. A novel hybrid approach to small-angle scattering data analysis was developed. In combination, these provided direct structural insight into membrane-protein localization in the nanodisc and into the protein-lipid interactions. It was found that bR is laterally decentred in the plane of the disc and is slightly tilted in the phospholipid bilayer. The thickness of the bilayer is reduced in response to the incorporation of bR. The observed tilt of bR is in good accordance with previously performed theoretical predictions and computer simulations based on the bR crystal structure. The result is a significant and essential step on the way to developing a general small-angle scattering-based method for determining the low-resolution structures of membrane proteins in physiologically relevant environments. PMID:24531471

  15. Pulsed Direct Current Electrospray: Enabling Systematic Analysis of Small Volume Sample by Boosting Sample Economy.

    PubMed

    Wei, Zhenwei; Xiong, Xingchuang; Guo, Chengan; Si, Xingyu; Zhao, Yaoyao; He, Muyi; Yang, Chengdui; Xu, Wei; Tang, Fei; Fang, Xiang; Zhang, Sichun; Zhang, Xinrong

    2015-11-17

    We had developed pulsed direct current electrospray ionization mass spectrometry (pulsed-dc-ESI-MS) for systematically profiling and determining components in small volume sample. Pulsed-dc-ESI utilized constant high voltage to induce the generation of single polarity pulsed electrospray remotely. This method had significantly boosted the sample economy, so as to obtain several minutes MS signal duration from merely picoliter volume sample. The elongated MS signal duration enable us to collect abundant MS(2) information on interested components in a small volume sample for systematical analysis. This method had been successfully applied for single cell metabolomics analysis. We had obtained 2-D profile of metabolites (including exact mass and MS(2) data) from single plant and mammalian cell, concerning 1034 components and 656 components for Allium cepa and HeLa cells, respectively. Further identification had found 162 compounds and 28 different modification groups of 141 saccharides in a single Allium cepa cell, indicating pulsed-dc-ESI a powerful tool for small volume sample systematical analysis. PMID:26488206

  16. Rotation testing in gene set enrichment analysis for small direct comparison experiments.

    PubMed

    Dørum, Guro; Snipen, Lars; Solheim, Margrete; Saebø, Solve

    2009-01-01

    Gene Set Enrichment Analysis (GSEA) is a method for analysing gene expression data with a focus on a priori defined gene sets. The permutation test generally used in GSEA for testing the significance of gene set enrichment involves permutation of a phenotype vector and is developed for data from an indirect comparison design, i.e. unpaired data. In some studies the samples representing two phenotypes are paired, e.g. samples taken from a patient before and after treatment, or if samples representing two phenotypes are hybridised to the same two-channel array (direct comparison design). In this paper we will focus on data from direct comparison experiments, but the methods can be applied to paired data in general. For these types of data, a standard permutation test for paired data that randomly re-signs samples can be used. However, if the sample size is very small, which is often the case for a direct comparison design, a permutation test will give very imprecise estimates of the p-values. Here we propose using a rotation test rather than a permutation test for estimation of significance in GSEA of direct comparison data with a limited number of samples. Our proposed rotation test makes GSEA applicable to direct comparison data with few samples, by depending on rotations of the data instead of permutations. The rotation test is a generalisation of the permutation test, and can in addition be used on indirect comparison data and for testing significance of other types of test statistics outside the GSEA framework. PMID:19645689

  17. Investigating common clinical presentations in first opinion small animal consultations using direct observation

    PubMed Central

    Robinson, N. J.; Dean, R. S.; Cobb, M.; Brennan, M. L.

    2015-01-01

    Understanding more about the clinical presentations encountered in veterinary practice is vital in directing research towards areas relevant to practitioners. The aim of this study was to describe all problems discussed during a convenience sample of consultations using a direct observation method. A data collection tool was used to gather data by direct observation during small animal consultations at eight sentinel practices. Data were recorded for all presenting and non-presenting specific health problems discussed. A total of 1901 patients were presented with 3206 specific health problems discussed. Clinical presentation varied widely between species and between presenting and non-presenting problems. Skin lump, vomiting and inappetence were the most common clinical signs reported by the owner while overweight/obese, dental tartar and skin lump were the most common clinical examination findings. Skin was the most frequently affected body system overall followed by non-specific problems then the gastrointestinal system. Consultations are complex, with a diverse range of different clinical presentations seen. Considering the presenting problem only may give an inaccurate view of the veterinary caseload, as some common problems are rarely the reason for presentation. Understanding the common diagnoses made is the next step and will help to further focus questions for future research. PMID:25564472

  18. Effects of saltcedar invasion and biological control on small mammals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of invasive saltcedars (Tamarix spp.) on bird populations and communities have received considerable interest, but impacts on other vertebrate taxa have received less attention. Moreover, only one published study examined effects on vertebrates of biological control efforts directed at saltc...

  19. The effect of beam directivity on the inspection of anisotropic materials using ultrasonic arrays

    NASA Astrophysics Data System (ADS)

    Lane, C. J. L.; Wilcox, P. D.

    2012-05-01

    The beam directivity from an ultrasonic transducer in isotropic materials is well documented. However, beam directivities in elastically anisotropic materials and their effect on ultrasonic NDE inspection has been investigated far less extensively. In this paper, analytical and numerical finite element models are developed to predict the beam directivity in a single crystal nickel-based superalloy. This material is highly anisotropic and is used widely in the gas-turbine industry. The developed models are used to investigate the effect of the crystallographic orientation on the beam directivity. In turn, the effect of beam directivity on defect detection sensitivity and characterization capability using an ultrasonic array is demonstrated. It is shown that the effect is particularly important for the accurate sizing of small defects.

  20. 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.

  1. Direct and Indirect Effects (First Draft, Comments Welcome)

    E-print Network

    California at Los Angeles, University of

    Direct and Indirect Effects (First Draft, Comments Welcome) Judea Pearl Cognitive Systems@cs.ucla.edu Abstract The direct effect of one event on another can be defined and measured by holding constant all intermediate variables between the two. Indirect effects present concep­ tual and practical difficulties (in

  2. Bi-directional small form pluggable optical transceiver using an integrated WDM optical subassembly

    NASA Astrophysics Data System (ADS)

    Yoon, Hyun-Jae; Cho, Hyun-Woo; Cho, Young-Uk; Kim, Ki-Dae

    2006-09-01

    The 1.3/1.55 ?m bi-directional small form pluggable (SFP) optical transceiver with an integrated wavelength division multiplexing (WDM) subassembly using accurate ceramic blocks has been developed. The WDM subassembly on which a laser diode (LD), a receiver photodiode (r-PD), a WDM filter, and two micro lenses are integrated is only 2.0 x 2.1 x 0.6 mm 3 in size and inserted in a TO-CAN package. The SFP transceiver coupled with single mode fiber has been operated at a 622Mbps data rate. The transmitted optical output power is -2.8 dBm and the measured value of sensitivity is -32 dBm at 10 -10 Bit Error Rate (BER).

  3. Validation of the ultrastable low-noise current amplifier as travelling standard for small direct currents

    NASA Astrophysics Data System (ADS)

    Drung, D.; Krause, C.; Giblin, S. P.; Djordjevic, S.; Piquemal, F.; Séron, O.; Rengnez, F.; Götz, M.; Pesel, E.; Scherer, H.

    2015-12-01

    An interlaboratory comparison of small-current generation and measurement capability is presented with the ultrastable low-noise current amplifier (ULCA) acting as travelling standard. Various measurements at direct currents between 0.16 nA and 13 nA were performed to verify the degree of agreement between the three national metrology institutes involved in the study. Consistency well within one part per million (ppm) was found. Due to harsh environmental conditions during shipment, the ULCA’s transfer accuracy had been limited to about??±0.4 ppm. Supplemental measurements performed at PTB indicate that further improvements in accuracy are possible. Relative uncertainties of 0.1 ppm are achieved by applying on-site calibration of the ULCA with a suitable cryogenic current comparator.

  4. 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. Department of Physics, The College of Wooster, Wooster, Ohio 44691 Naval Surface Warfare Center, Silver Spring, Maryland 20902 )

    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.

  5. Small molecule-mediated directed differentiation of human embryonic stem cells toward ventricular cardiomyocytes.

    PubMed

    Karakikes, Ioannis; 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

  6. HORTICULTURAL ENTOMOLOGY Small Plot Trials Documenting Effective Mating Disruption of

    E-print Network

    Burns, Jacqueline K.

    HORTICULTURAL ENTOMOLOGY Small Plot Trials Documenting Effective Mating Disruption of Oriental were evaluated in 0.05-ha (12-tree) plots of ÔDeliciousÕ apples receiving regular maintenance according-Rosso ropes at 1.8 per tree (500/ha) and untreated control plots. Treatments were applied before the start

  7. Effects of Directional Exercise on Lingual Strength

    ERIC Educational Resources Information Center

    Clark, Heather M.; O'Brien, Katy; Calleja, Aimee; Corrie, Sarah Newcomb

    2009-01-01

    Purpose: To examine the application of known muscle training principles to tongue strengthening exercises and to answer the following research questions: (a) Did lingual strength increase following 9 weeks of training? (b) Did training conducted using an exercise moving the tongue in one direction result in strength changes for tongue movements in…

  8. Electrical response of an electrolytic cell submitted to a small direct current electric field when the electrodes are ohmic

    NASA Astrophysics Data System (ADS)

    Barbero, Giovanni; da Silva, Jonatan João; Figueiredo Neto, Antonio Martins

    2007-06-01

    We theoretically investigate the influence of the ohmic character of the electrodes on the direct current (dc) response and on the ionic relaxation time of an electrolytic cell, in the shape of a slab. The analysis is performed by assuming that the fundamental equations of the problem can be linearized. This implies that, for monovalent ions, the applied difference of potential is smaller than 25 mV. We show that the finite ohmic conductivity of the electrodes is responsible for a reduction of the relaxation time. An explicit expression for the relaxation time, valid when the Debye length is very small with respect to the thickness of the sample is deduced. The analysis of the dc current allows us to determine the contribution of the electrodes to the effective electrical resistance. We show also that the equivalent circuit relevant to the present problem cannot be used to evaluate the relaxation time of the cell.

  9. 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.

    . ____________________________ ____________________________ Robert Kelly, Ph.D. James Brown, Ph.D. Minor Chair Chair of Advisory Committee #12;ii DEDICATION, and the Small Ribosomal Subunit. (Under the Direction of James W. Brown). The term RNA world was first coined was predicated on the Watson Crick Model 3) Genetically encoded proteins were not catalytic. An example

  10. 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.

  11. Effects of small halocarbon molecules on reverse osmosis membrane performance

    SciTech Connect

    Cheng, R.C.; Glater, J.; Neethling, J.B. )

    1990-01-01

    The reverse osmosis (RO) membrane industry has long been concerned with problems of performance decline due to fouling. Colloidal and biological fouling have been discussed to some extent in the literature but little is known about the effect of small organic molecules on membrane performance. The work reported in this paper involved controlled laboratory experiments with three small halocarbons and three different types of commercial RO membranes. The compounds used were CHCl{sub 3}, CHBr{sub 3} and CCl{sub 4}. The first two represent typical small and large THM's. Carbon tetrachloride was selected as a non-polar model compound. Membranes representing three different polymer systems were provided by E. I. du Pont Inc.

  12. Synopsis of Direct and Indirect Lightning Effects on Composite Materials

    NASA Technical Reports Server (NTRS)

    Clark, Tony

    1998-01-01

    NASA's Space Environments and Effects (SEE) Program funded a study on electromagnetic environmental effect issues of composite materials used by the aerospace industry. The results of which are published by Ross Evans, Tec-Masters Inc., in NASA-CR-4783, "Test Report - Direct and Indirect Lightning Effects on Composite Materials." Indirect effects include the electric and magnetic field shielding provided by a composite material illuminated by a near or direct lightning strike. Direct effects includes the physical damage of composites and/or assembly joint with a direct strike injection. This paper provides a synopsis of NASA-CR-4783. A short description is provided of the direct and indirect tests performed during the sturdy. General results and design guidelines are discussed.

  13. 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

  14. Aspirin Induced Adverse Effects on the Small and Large Intestine.

    PubMed

    Pavlidis, Polychronis; Bjarnason, Ingvar

    2015-01-01

    Aspirin is in many ways a non- steroidal anti-inflammatory drug (NSAID) prototype. Similar to conventional NSAIDs the gastric side effects of aspirin are well studied. However its potential adverse effects on the small and large intestine are less well known and under- researched. Experimental studies support a pathogenic pathway leading to NSAID enteropathy involving the topical effects on the intestinal barrier (mucous layer, enterocytes) that lead to dysfunction and increased intestinal permeability followed by increased exposure to luminal triggers and acute inflammation. Although aspirin has a toxic effect in vitro, enteral or parenteral administration in vivo, in animal models, did not result to intestinal injury. In man, experimental studies have revealed changes in intestinal permeability similar to conventional NSAIDs but of lesser magnitude. The clinical implication of these changes though is not known. Population studies have associated aspirin use with occult gastrointestinal bleeding from the small or large bowel although the magnitude of this risk is difficult to estimate but certainly small. Associations to colitis flare-ups have been made in case reports and retrospective cohort studies but low dose aspirin appears safe. Complications of diverticular disease may also be more frequent with aspirin use. PMID:26369683

  15. A super multi-view display with small viewing zone tracking using directional backlight

    NASA Astrophysics Data System (ADS)

    Miyazaki, Jin; Yendo, Tomohiro

    2015-03-01

    A super multi-view display provides smooth motion parallax without special glasses, and it is expected that the observer is free from the visual fatigue caused by the accommodation-vergence conflict. However, a huge number of pixels are required on a display device because high-density rays are required for good quality images and each ray needs corresponding pixel. We have proposed a method to reduce the required number of pixels by limiting rays emitted to only around observer's pupils. The display is based on the lenticular method. As stated above, the rays should be shot out to only around observer's pupils. To do this, the lenticular lens of which viewing zone angle is narrowed is used and the lenticular lens is illuminated by directional light to suppress side lobes. The direction of directional light is changed to follow the observer's pupil. In this paper, we constructed a prototype display and conducted an experiment. The experimental result confirmed that we could see image corresponding from each viewpoint by the change of the photographing images. In addition, it confirmed suppression of the side lobes by couldn't see the image outside the viewing zone. By these results, we showed the effectiveness of the proposed method.

  16. 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.

  17. Small-angle light scattering to detect strain-directed collagen degradation in native tissue

    PubMed Central

    Robitaille, Michael C.; Zareian, Ramin; DiMarzio, Charles A.; Wan, Kai-Tak; Ruberti, Jeffrey W.

    2011-01-01

    It has been demonstrated that there is a mechanochemical relationship between collagen and collagenolytic enzymes such that increased tensile mechanical strain reduces the enzymatic cutting rate. This mechanochemical relationship has the potential to permit directed remodelling of tissue-engineered constructs in vitro and to shed light on the generation of load-adapted collagen-based connective tissue. In this investigation, we demonstrate that small-angle light scattering (SALS) has the sensitivity to dynamically detect the preferential enzymatic degradation of a subset of unloaded collagen fibrils within differentially loaded native tissue. Detection of the difference in the relative degradation rate of unloaded fibrils versus loaded fibrils was manifested through changes in the spatial distribution of the SALS signal. Specifically, we found a linear increase in the eccentricity of the SALS data that was consistent with preferential retention of the collagen fibrils aligned with the applied tensile strain. We conclude that SALS is simple, inexpensive and may provide a useful optical screening method permitting real-time monitoring of strain-controlled tissue and construct remodelling. PMID:23050081

  18. Small-angle light scattering to detect strain-directed collagen degradation in native tissue.

    PubMed

    Robitaille, Michael C; Zareian, Ramin; Dimarzio, Charles A; Wan, Kai-Tak; Ruberti, Jeffrey W

    2011-10-01

    It has been demonstrated that there is a mechanochemical relationship between collagen and collagenolytic enzymes such that increased tensile mechanical strain reduces the enzymatic cutting rate. This mechanochemical relationship has the potential to permit directed remodelling of tissue-engineered constructs in vitro and to shed light on the generation of load-adapted collagen-based connective tissue. In this investigation, we demonstrate that small-angle light scattering (SALS) has the sensitivity to dynamically detect the preferential enzymatic degradation of a subset of unloaded collagen fibrils within differentially loaded native tissue. Detection of the difference in the relative degradation rate of unloaded fibrils versus loaded fibrils was manifested through changes in the spatial distribution of the SALS signal. Specifically, we found a linear increase in the eccentricity of the SALS data that was consistent with preferential retention of the collagen fibrils aligned with the applied tensile strain. We conclude that SALS is simple, inexpensive and may provide a useful optical screening method permitting real-time monitoring of strain-controlled tissue and construct remodelling. PMID:23050081

  19. An interface for the direct coupling of small liquid samples to AMS

    NASA Astrophysics Data System (ADS)

    Ognibene, T. J.; Thomas, A. T.; Daley, P. F.; Bench, G.; Turteltaub, K. W.

    2015-10-01

    We describe the moving wire interface attached to the 1-MV AMS system at LLNL's Center for Accelerator Mass Spectrometry for the analysis of nonvolatile liquid samples as either discrete drops or from the direct output of biochemical separatory instrumentation, such as high-performance liquid chromatography (HPLC). Discrete samples containing at least a few 10 s of nanograms of carbon and as little as 50 zmol 14C can be measured with a 3-5% precision in a few minutes. The dynamic range of our system spans approximately 3 orders in magnitude. Sample to sample memory is minimized by the use of fresh targets for each discrete sample or by minimizing the amount of carbon present in a peak generated by an HPLC containing a significant amount of 14C. Liquid sample AMS provides a new technology to expand our biomedical AMS program by enabling the capability to measure low-level biochemicals in extremely small samples that would otherwise be inaccessible.

  20. Measuring Bi-Directional Reflectance with a Constellation of SmallSats

    NASA Astrophysics Data System (ADS)

    Nag, S.; Gatebe, C. K.; Wiscombe, W. J.; de Weck, O. L.

    2013-12-01

    : The "missing carbon" problem has plagued the carbon cycle field for over 30 years. A newly proposed constellation of satellites promises to finally close the gap and find the missing carbon. This constellation would measure vegetation from multiple angles at solar wavelengths, essentially measuring the bidirectional reflectance (BRDF), and from this retrieve the Gross Primary Productivity, something that has eluded space remote sensing up until now. The science value of such an approach is demonstrated by using multi-angle, multi-spectral measurements from various deployments of the Cloud Absorption Radiometer (CAR) as the 'gold standard' data for BRDF estimation. CAR is an airborne instrument operated by NASA Goddard Space Flight Center. CAR data are used to estimate the parameters of the widely-used Rahman-Pinty-Verstraete (RPV) and RossThin-LiSparseReciprocal (RTnLS) BRDF models. While CAR reflectance data is obtained at 360 view-azimuth directions and 90 view-zenith directions, satellite clusters will be able to sample only a part of this angular space. To make best use of the satellite-cluster BRDF data, a heuristic optimization method is used to find the best angular sub-sampling. Also, different closed loop formation-flying geometries are considered. We will show the effect of these formation-flying architectures on BRDF estimation errors and identify an optimal baseline architecture that will reduce errors when compared to existing spaceborne instruments like MODIS and MISR.

  1. Effects of 2D small-scale sedimentary basins on strong ground motion characteristics

    NASA Astrophysics Data System (ADS)

    Movahedasl, R.; Ghayamghamian, M. R.

    2015-08-01

    A lot of research on the 2D or 3D effects of large-scale basins (within several kilometers depth) have been conducted in the past. However, different 2D aspects of small-scale sedimentary basins (within tens of meters depth) remain in the developing stage. Here, an attempt is made to analyze different aspects of small-scale basins using both numerical and empirical investigations. In the first step, the 2D effects of small-scale basins on strong motion characteristics are numerically examined both in the time and frequency domains. In addition, the effects of input motion are also explained by the results of model excitation in different orthogonal directions. Then, the numerical outcomes are verified by the analysis of actual earthquake data recorded at a downhole array in the Fujisawa small basin, Japan. In the second step, since available recorded earthquake data in small basins with a clear understanding of subsurface geology are very limited, different 2D aspects of the small basin are parametrically investigated. For this purpose, extensive parametrical studies are carried out on the main features of a small basin such as slope angle, shape, infill soil properties, and basin thickness by using the finite difference numerical method. The horizontal and vertical peak ground accelerations of 2D with respect to 1D ones are defined as the horizontal and vertical aggravation factors (AGH and AGV). The AGH and AGV factors show large sensitivity to infill soil properties, shape and thickness, and small sensitivity to slope angle. The values of AGH and AGV factors vary in the range of 0.5-2 with large variations around small basin edges due to wave coupling, conversion, scattering and focusing in the vicinity of small basin edges. These cause a complicated pattern of 2D de-amplification and amplification, which mostly affect the motion in the high frequency range (>1?Hz). Finally, the outcomes provide numerical and field evidence on the 2D effects of small basins, and give some recommendations for design codes.

  2. Effective Practice in the Design of Directed Independent Learning Opportunities

    ERIC Educational Resources Information Center

    Thomas, Liz; Jones, Robert; Ottaway, James

    2015-01-01

    This study, commissioned by the HEA and the QAA focuses on directed independent learning practices in UK higher education. It investigates what stakeholders (including academic staff and students) have found to be the most effective practices in the inception, design, quality assurance and enhancement of directed independent learning and explores…

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

    E-print Network

    Schneck, K.

    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 ...

  4. Cost-Effective Icy Bodies Exploration using Small Satellite Missions

    NASA Technical Reports Server (NTRS)

    Jonsson, Jonas; Mauro, David; Stupl, Jan; Nayak, Michael; Aziz, Jonathan; Cohen, Aaron; Colaprete, Anthony; Dono-Perez, Andres; Frost, Chad; Klamm, Benjamin; McCafferty, Julian; McKay, Chris; Sears, Derek; Soulage, Michael; Swenson, Jason; Weston, Sasha; Yang Yang, Fan

    2015-01-01

    It has long been known that Saturn's moon Enceladus is expelling water-rich plumes into space, providing passing spacecraft with a window into what is hidden underneath its frozen crust. Recent discoveries indicate that similar events could also occur on other bodies in the solar system, such as Jupiter's moon Europa and the dwarf planet Ceres in the asteroid belt. These plumes provide a possible giant leap forward in the search for organics and assessing habitability beyond Earth, stepping stones toward the long-term goal of finding extraterrestrial life. The United States Congress recently requested mission designs to Europa, to fit within a cost cap of $1B, much less than previous mission designs' estimates. Here, innovative cost-effective small spacecraft designs for the deep-space exploration of these icy worlds, using new and emerging enabling technologies, and how to explore the outer solar system on a budget below the cost horizon of a flagship mission, are investigated. Science requirements, instruments selection, rendezvous trajectories, and spacecraft designs are some topics detailed. The mission concepts revolve around a comparably small-sized and low-cost Plume Chaser spacecraft, instrumented to characterize the vapor constituents encountered on its trajectory. In the event that a plume is not encountered, an ejecta plume can be artificially created by a companion spacecraft, the Plume Maker, on the target body at a location timed with the passage of the Plume Chaser spacecraft. Especially in the case of Ceres, such a mission could be a great complimentary mission to Dawn, as well as a possible future Europa Clipper mission. The comparably small volume of the spacecraft enables a launch to GTO as a secondary payload, providing multiple launch opportunities per year. Plume Maker's design is nearly identical to the Plume Chaser, and fits within the constraints for a secondary payload launch. The cost-effectiveness of small spacecraft missions enables the exploration of multiple solar system bodies in reasonable timeframes despite budgetary constraints, with only minor adaptations. The work presented here is a summary of concepts targeting icy bodies, such as Europa and Ceres, which have been developed over the last year at NASA Ames Research Center's Mission Design Division. The platforms detailed in this work are also applicable to the cost-effective exploration of many other small icy bodies in the solar system.

  5. 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.

  6. Direct radiative effect by multicomponent aerosol over China

    SciTech Connect

    Huang, Xin; Song, Yu; Zhao, Chun; Cai, Xuhui; Zhang, Hongsheng; Zhu, Tong

    2015-05-01

    The direct radiative effect (DRE) of multiple aerosol species (sulfate, nitrate, ammonium, black carbon (BC), organic carbon (OC), and mineral aerosol) and their spatiotemporal variations over China were investigated using a fully coupled meteorology–chemistry model (WRF-Chem) for the entire year of 2006. We made modifications to improve model performance, including updating land surface parameters, improving the calculation of transition metal-catalyzed oxidation of SO2, and adding in heterogeneous reactions between mineral aerosol and acid gases. The modified model well reproduced the magnitude, seasonal pattern, and spatial distribution of the measured meteorological conditions, concentrations of PM10 and its components, and aerosol optical depth (AOD). A diagnostic iteration method was used to estimate the overall DRE of aerosols and contributions from different components. At the land surface, all kinds of aerosol species reduced the incident net radiation flux with a total DRE of 10.2 W m-2 over China. Aerosols significantly warm the atmosphere with the national mean DRE of +10.8 W m-2. BC was the leading radiative-heating component (+8.7 W m-2), followed by mineral aerosol (+1.1 W m-2). At the top of the atmosphere (TOA), BC introduced the largest radiative perturbation (+4.5 W m-2), followed by sulfate (-1.4 W m-2). The overall perturbation of aerosols on radiation transfer is quite small over China, demonstrating the counterbalancing effect between scattering and adsorbing aerosols. Aerosol DRE at the TOA had distinct seasonality, generally with a summer maximum and winter minimum, mainly determined by mass loadings, hygroscopic growth, and incident radiation flux.

  7. Why is the electrocaloric effect so small in ferroelectrics?

    NASA Astrophysics Data System (ADS)

    Guzman-Verri, Gian G.; Littlewood, Peter B.

    2015-03-01

    Ferroelectrics are attractive candidate materials for environmentally friendly solid state refrigeration free of greenhouse gases. Their thermal response upon variations of external electric fields is largest in the vicinity of their phase transitions, which may occur near room temperature. The magnitude of the effect, however, is too small for useful cooling applications even when they are driven close to dielectric breakdown. Insight from microscopic theory is therefore needed to characterize materials and provide guiding principles to search for new ones with enhanced electrocaloric performance. Here, we present meaningful figures of merit derived from well-known microscopic models of ferroelectricity which provide insight into the relation between the strength of the effect and the characteristic interactions of ferroelectrics such as dipole forces. We find that the long range nature of these interactions results in a small effect. A strategy is proposed to make it larger by shortening the correlation lengths of fluctuations of polarization. Work at Argonne is supported by the U.S. Department of Energy, Office of Basic Energy Sciences under Contract No. DE-AC02-06CH11357.

  8. 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-microscopy from cryo-electron microscopy supports the correctness of the polyoma structure solved structures: image analysis of electron micrographs of frozen- hydrated samples (SV40 virions

  9. Nonlinear Superposition of Direct and Inverse Cascades in Two-Dimensional Turbulence Forced at Large and Small Scales

    E-print Network

    Cencini, Massimo

    at large and small scale and exhibiting a direct enstrophy and an inverse-energy cascade, respectively cascade proceeds undisturbed, with a negative energy flux (% Ã?), unless large-scale friction stops it at a scale ) `f [4]. For a recent numerical study of the dual cascade see [5]. In 3D layers

  10. Direct Kerr electro-optic effect in noncentrosymmetric materials

    SciTech Connect

    Melnichuk, Mike; Wood, Lowell T.

    2010-07-15

    In materials lacking inversion symmetry, both Pockels and Kerr electro-optic effects are simultaneously present, with the former effect generally dominating the latter one. The theoretical findings of this article provide the crystal physics community with concrete tabulated evidence showing that it is possible in principle to selectively bypass contributions from the linear effect(s) and directly obtain information only about the genuine (Kerr-like) quadratic effects in 90% of the noncentrosymmetric point groups. The general idea and treatment used for the electro-optic effect can be extended and adapted to other optical or non-optical (phenomenological) purely quadratic effects in media lacking inversion symmetry.

  11. Using network meta-analysis to evaluate the existence of small-study effects in a network of interventions.

    PubMed

    Chaimani, Anna; Salanti, Georgia

    2012-06-01

    Suggested methods for exploring the presence of small-study effects in a meta-analysis and the possibility of publication bias are associated with important limitations. When a meta-analysis comprises only a few studies, funnel plots are difficult to interpret, and regression-based approaches to test and account for small-study effects have low power. Assuming that the cause of funnel plot asymmetry is likely to affect an entire research field rather than only a particular comparison of interventions, we suggest that network meta-regression is employed to account for small-study effects in a set of related meta-analyses. We present several possible models for the direction and distribution of small-study effects and we describe the methods by re-analysing two published networks. Copyright © 2012 John Wiley & Sons, Ltd. PMID:26062088

  12. 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

  13. Measuring Bi-Directional Reflectance for Gross Primary Productivity with a Constellation of SmallSats

    NASA Astrophysics Data System (ADS)

    Nag, S.; Gatebe, C. K.; Hilker, T.; Hall, F. G.; de Weck, O. L.

    2014-12-01

    The "missing carbon" problem has plagued the carbon cycle field for over 30 years. A newly proposed constellation of satellites promises to finally close the gap and find the missing carbon. This constellation would measure vegetation from multiple angles at solar wavelengths, essentially measuring the bidirectional reflectance (BRDF), and from this retrieve the Gross Primary Productivity (GPP), something that has eluded space remote sensing community up until now, showing up to 40% uncertainty. The science value of such a BRDF retrieval approach has been demonstrated using multi-angle, multi-spectral measurements from various deployments of the Cloud Absorption Radiometer (CAR) as the "gold standard" data for BRDF estimation. CAR is an airborne instrument operated by NASA Goddard Space Flight Center. Initial observing system simulations (OSSE) with four satellites launched as secondary payloads and operating in different imaging modes show BRDF error estimates of less than 12% when compared to CAR measurements, a 50% improvement to the worst case BRDF error produced by corresponding monoliths. However, GPP products require estimating the BRDF of photochemical reflectance index (PRI), which needs angular measurements at the xanthophyll sensitive band (533nm) - unavailable in CAR. The satellite OSSEs will be repeated using AMPSEC tower measurements. AMPSEC is a Unispec-DC (PP Systems, Amesbury,MA, USA) spectroradiometer with 256 contiguous bands with a nominal band spacing of 3 nm and a nominal range of operation between 350 and 1200 nm. The data will be used to estimate parameters of the widely-used Rahman-Pinty-Verstraete (RPV) and RossThin-LiSparseReciprocal (RTnLS) BRDF models. Since AMPSEC reflectance data is obtained at 360 view-azimuth directions and 90 view-zenith directions, satellite clusters will be able to sample only a part of this angular space. To make best use of the satellite-cluster BRDF data, a heuristic optimization method is used to find the best angular sub-sampling. Also, different closed loop formation-flying geometries are considered. We will show the effect of these formation-flying architectures on BRDF, PRI and GPP estimation errors and identify an optimal baseline architecture that will reduce errors when compared to existing spaceborne instruments such as MODIS and MISR.

  14. Radiation Synovectomy: an effective alternative treatment for inflamed small joints

    PubMed Central

    Karavida, N; Notopoulos, A

    2010-01-01

    An inflamed painful joint is one of the most common indications for the patient to be referred to a rheumatologist or an orthopedician. In relation to the aetiology, the therapeutic approach might be systemic, local or a combination of them in some cases, always with the thought of balancing risk with benefit for the patient. In all cases, independently of the cause, the goal of therapy is to improve the quality of life through the reduction of pain, improvement of mobility and preservation of function. Nuclear Medicine has to offer Radiosynoviorthesis, an effective alternative procedure for treating inflamed small joints. Various radionuclides are available for radiosynoviorthesis. Their selection depends on the size of the joint to be treated. Small joints are mainly treated with [169Er] erbium under a fluoroscopic or sonographic guidance, usually with a simultaneous instillation of a corticoid. Candidates for radiosynoviorthesis should have been under a six-month systemic treatment without encouraging results or should have undergone at least one unsuccessful intra-articular injection of a long acting glucocorticoid. Since 1973, when [169Er] erbium was firstly suggested as a therapeutic agent for radiosynoviorthesis of the finger joints, there has been quite enough experience in its' application. It has been found to be cost effective in providing long term relief of pain and deformity of the inflamed joints in comparison to other therapeutic approaches. Additionally, there is no radiation risk and can be performed on an out patient basis. Therefore it can stand as an effective alternative procedure for treating early stages of chronic synovitis in RA (rheumatoid arthritis) patients, with minor damage of the cartilage and the adjacent bones, and for synovitis secondary to inflammatory arthropathies. PMID:20411055

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

    SciTech Connect

    Slotman, Ben J.; Senan, Suresh

    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.

  16. Sequence-Defined Peptidocopolymers: The Effect of Small Molecular Linkers.

    PubMed

    Liu, Yijiang; Kang, Yu; Wang, Jue; Wang, Zheyu; Chen, Guosong; Jiang, Ming

    2015-12-14

    In this paper, the contribution of nonpeptido small molecular linkers to the properties of sequence-defined peptidocopolymers was investigated. We synthesized four novel bioinspired peptidocopolymers (P1-P4) based on elastin motif pentapeptide (Gly-Pro-Gly-Gly-Ala) by step growth polymerization. Small molecular linkers, including tetraethylene glycol (M1), adipic acid (M2), isophthalic acid (M3), and terephthalic acid (M4) with different length and flexibility are employed to tune the conformation, physical, and mechanical properties of the corresponding peptidocopolymers P1-P4 respectively. Raman spectroscopy, solid state NMR, and circular dichroism spectroscopy were used to characterize the conformation of the four peptidocopolymers. The experimental results were further confirmed by molecular dynamics simulation of typical P2 and P4 with different repeating units. High ratio of ?-turn conformation was observed in P2 due to flexible linker M2; while affected by the hydrophobic and rigid M4 linker, P4 retained less ?-turn conformation and showed drastic difference on macroscopic properties. These simple step growth synthesis techniques provide an efficient approach toward a broad range of bioinspired peptidocopolymers, which takes a further insight into the significant effect of nonpeptido linkages toward chemical-synthesized peptidocopolymers. PMID:26538230

  17. 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.

  18. Direction of movement effects under transformed visual/motor mappings

    NASA Technical Reports Server (NTRS)

    Cunningham, H. A.; Pavel, M.

    1989-01-01

    Performance in a discrete aiming task was compared under several transformed visual/motor mappings: rotations by 45, 90, 135, and 180 deg and reflections about the horizontal and the vertical midlines. Eight aiming targets were used, corresponding to eight directions of movement: up, down, right, left, up-right, down-left, up-left, and down-right. Direction of movements were characterized in terms of separable visual and motor components, and two kinds of direction of movement effects were considered. First, a direction of movement effect paralleling that seen in rapid aiming under the usual nontransformed mapping. Second, because rotations, but not reflections, are physically realizable 2-D transformations, a visual/motor control system which is sensitive to physical constraints should perform reflections, but not rotations, in a piecemeal fashion. Results supported the hypothesis that a motor factor having to do with complexity of limb movement accounts for differences in movement accuracy between right and left oblique directions. Direction of movement effects were more evident in reflections than in rotations, and were consistent with the hypothesis that the visual/motor-control system seeks a physically realizable 2-D rotation solution to reflections. Results also suggested that reversal of two orthogonal basis dimensions is far less difficult than reversing only one and leaving the other intact.

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

    NASA Technical Reports Server (NTRS)

    Schnitzler, Bruce G.; Borowski, Stanley K.

    2012-01-01

    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 the 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.

  20. 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.

  1. 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.

  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. Why do pitched horizontal lines have such a small effect on visually perceived eye level?

    NASA Technical Reports Server (NTRS)

    Post, R. B.; Welch, R. B.; Clark, V. D.

    2000-01-01

    In two experiments, visually perceived eye level (VPEL) was measured while subjects viewed two-dimensional displays that were either upright or pitched 20 degrees top-toward or 20 degrees top-away from them. In Experiment 1, it was demonstrated that binocular exposure to a pair of pitched vertical lines or to a pitched random dot pattern caused a substantial upward VPEL shift for the top-toward pitched array and a similarly large downward shift for the top-away array. On the other hand, the same pitches of a pair of horizontal lines (viewed binocularly or monocularly) produced much smaller VPEL shifts. Because the perceived pitch of the pitched horizontal line display was nearly the same as the perceived pitch of the pitched vertical line and dot array, the relatively small influence of pitched horizontal lines on VPEL cannot be attributed simply to an underestimation of their pitch. In Experiment 2, the effects of pitched vertical lines, dots, and horizontal lines on VPEL were again measured, together with their effects on resting gaze direction (in the vertical dimension). As in Experiment 1, vertical lines and dots caused much larger VPEL shifts than did horizontal lines. The effects of the displays on resting gaze direction were highly similar to their effects on VPEL. These results are consistent with the hypothesis that VPEL shifts caused by pitched visual arrays are due to the direct influence of these arrays on the oculomotor system and are not mediated by perceived pitch.

  4. 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.

  5. 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.

  6. 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

  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. 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…

  9. Effect of spine hardware on small spinal stereotactic radiosurgery dosimetry.

    PubMed

    Wang, Xin; Yang, James N; Li, Xiaoqiang; Tailor, Ramesh; Vassilliev, Oleg; Brown, Paul; Rhines, Laurence; Chang, Eric

    2013-10-01

    Monte Carlo (MC) modeling of a 6 MV photon beam was used to study the dose perturbation from a titanium rod 5 mm in diameter in various small fields range from 2 × 2 to 5 × 5 cm(2). The results showed that the rod increased the dose to water by ?6% at the water-rod interface because of electron backscattering and decreased the dose by ?7% in the shadow of the rod because of photon attenuation. The Pinnacle(3) treatment planning system calculations matched the MC results at the depths more than 1 cm past the rod when the correct titanium density of 4.5 g cm(-3) was used, but significantly underestimated the backscattering dose at the water-rod interface. A CT-density table with a top density of 1.82 g cm(-3) (cortical bone) is a practical way to reduce the dosimetric error from the artifacts by preventing high density assignment to them, but can underestimates the attenuation by the titanium rod by 6%. However, when multi-beam with intensity modulation is used in actual patient spinal stereotactic radiosurgery treatment, the dosimetric effect of assigning 4.5 instead of 1.82 g cm(-3) to titanium implants is complicated. It ranged from minimal effect to 2% dose difference affecting 15% target volume in the study. When hardware is in the beam path, density override to the titanium hardware is recommended. PMID:24018829

  10. Changing Directions: Young People and Effective Work against Racism

    ERIC Educational Resources Information Center

    Thomas, Paul; Henri, Tom

    2011-01-01

    This article explores effective approaches against racism in work with young people, and the relevance of new policy agendas in the UK. Since the 2001 disturbances, the UK has controversially prioritised "Community Cohesion", with the accusation that this new direction represents the "death of multiculturalism". Drawing on empirical evidence from…

  11. Wind-Direction Effects on Urban-Type Flows

    NASA Astrophysics Data System (ADS)

    Claus, Jean; Coceal, O.; Thomas, T. Glyn; Branford, S.; Belcher, S. E.; Castro, Ian P.

    2012-02-01

    Practically all extant work on flows over obstacle arrays, whether laboratory experiments or numerical modelling, is for cases where the oncoming wind is normal to salient faces of the obstacles. In the field, however, this is rarely the case. Here, simulations of flows at various directions over arrays of cubes representing typical urban canopy regions are presented and discussed. The computations are of both direct numerical simulation and large-eddy simulation type. Attention is concentrated on the differences in the mean flow within the canopy region arising from the different wind directions and the consequent effects on global properties such as the total surface drag, which can change very significantly—by up to a factor of three in some circumstances. It is shown that for a given Reynolds number the typical viscous forces are generally a rather larger fraction of the pressure forces (principally the drag) for non-normal than for normal wind directions and that, dependent on the surface morphology, the average flow direction deep within the canopy can be largely independent of the oncoming wind direction. Even for regular arrays of regular obstacles, a wind direction not normal to the obstacle faces can in general generate a lateral lift force (in the direction normal to the oncoming flow). The results demonstrate this and it is shown how computations in a finite domain with the oncoming flow generated by an appropriate forcing term (e.g. a pressure gradient) then lead inevitably to an oncoming wind direction aloft that is not aligned with the forcing term vector.

  12. Measurement of illite particle thickness using a direct Fourier transform of small-angle X-ray scattering data

    USGS Publications Warehouse

    Shang, C.; Rice, J.A.; Eberl, D.D.; Lin, S.-J.

    2003-01-01

    It has been suggested that interstratified illite-smectite (I-S) minerals are composed of aggregates of fundamental particles. Many attempts have been made to measure the thickness of such fundamental particles, but each of the methods used suffers from its own limitations and uncertainties. Small-angle X-ray scattering (SAXS) can be used to measure the thickness of particles that scatter X-rays coherently. We used SAXS to study suspensions of Na-rectorite and other illites with varying proportions of smectite. The scattering intensity (I) was recorded as a function of the scattering vector, q = (4 ??/??) sin(??/2), where ?? is the X-ray wavelength and ?? is the scattering angle. The experimental data were treated with a direct Fourier transform to obtain the pair distance distribution function (PDDF) that was then used to determine the thickness of illite particles. The Guinier and Porod extrapolation were used to obtain the scattering intensity beyond the experimental q, and the effects of such extrapolations on the PDDF were examined. The thickness of independent rectorite particles (used as a reference mineral) is 18.3 A??. The SAXS results are compared with those obtained by X-ray diffraction peak broadening methods. It was found that the power-law exponent (??) obtained by fitting the data in the region of q = 0.1 -0.6 nm-1 to the power law (I = Ioq-??) is a linear function of illite particle thickness. Therefore, illite particle thickness could be predicted by the linear relationship as long as the thickness is within the limit where ?? <4.0.

  13. 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. . Dept. of Zoology); Rose, K.A. )

    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.

  14. 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.; Rose, K.A.

    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.

  15. Direct experimental determination of the anisotropic magnetoresistive effects

    NASA Astrophysics Data System (ADS)

    Perna, P.; Maccariello, D.; Rodrigo, C.; Cuñado, J. L. F.; Muñoz, M.; Prieto, J. L.; Niño, M. A.; Bollero, A.; Camarero, J.; Miranda, R.

    2014-05-01

    We present an experimental study devoted to determine the magnetoresistive signals as imposed by the system magnetic anisotropy and applied current direction in a model ferromagnetic system. By having direct experimental access to the magnetization vector during the reversal (measured through angular- and field-dependent vectorial-resolved magnetization loops), we can predict both longitudinal and transverse magnetoresistive signals, i.e., anisotropic magnetoresistance and planar Hall effect. This has been done by experimentally disclosing the resistance changes occurring during (and simultaneously to) the magnetization reversal processes.

  16. Effects of directed and kinetic energy weapons on spacecraft

    SciTech Connect

    Fraas, A P

    1986-12-01

    The characteristics of the various directed energy beams are reviewed, and their damaging effects on typical materials are examined for a wide range of energy pulse intensities and durations. Representative cases are surveyed, and charts are presented to indicate regions in which damage to spacecraft structures, particularly radiators for power plants, would be likely. The effects of kinetic energy weapons, such as bird-shot, are similarly examined. The charts are then applied to evaluate the effectiveness of various measures designed to reduce the vulnerability of spacecraft components, particularly nuclear electric power plants.

  17. The study of effects of small perturbations on chaotic systems

    SciTech Connect

    Grebogi, C. . Lab. for Plasma Research); Yorke, J.A. . Inst. for Physical Science and Technology)

    1990-12-01

    This report discusses the following topics on small perturbations on chaotic systems: controlling chaos; shadowing and noise reduction; chaotic scattering; random maps; magnetic dynamo; and aids transmission. (LSP)

  18. Opinion dynamics within a virtual small group: the stubbornness effect

    NASA Astrophysics Data System (ADS)

    Guazzini, Andrea; Cini, Alessandro; Bagnoli, Franco; Ramasco, José

    2015-09-01

    The modeling of opinion dynamics is social systems has attracted a good deal of attention in the last decade. Even though based on intuition and observation, the mechanisms behind many of these models need solid empirical grounding. In this work, we investigate the relation among subjective variables (such as the personality), the dynamics of the affinity network dynamics, the communication patterns emerging throughout the social interactions and the opinions dynamics in a series of experiments with five small groups of ten people each. In order to ignite the discussion, the polemic topic of animal experimentation was proposed. The groups essentially polarized in two factions with a set of stubborn individuals (those not changing their opinions in time) playing the role of anchors. Our results suggest that the different layers present in the group dynamics (i.e., individual level, group dynamics and meso-communication) are deeply intermingled, specifically the stubbornness effect appears to be related to the dynamical features of the network topologies, and only in an undirected way to the personality of the participants.

  19. [Effects of food on motility of the small intestine].

    PubMed

    Ducrotté, P; Denis, P; Colin, R

    1989-02-15

    It is now well-known that feeding suppresses the phase 3 propagated waves for 2.30 to 10 hours in the small intestine. This finding can be influenced by subject's age, ingestion time and nature of food. The influence of extraluminal factors, i.e. nervous or hormonal, is probable. First, a reduction of jejunal contractions frequency without alteration of their amplitude can be found in the elderly. Second, a late dinner can shorten by 50 per cent the duration of the post-prandial motor profile, which is followed by an irregular activity normally nearly absent and without reappearance of a reduced periodicity of phase 3. In man as in animal, the duration of the post-prandial inhibition is correlated with the caloric content of the meal. At equal colonic content a lipidic meal induces a stronger effect than a glucidic meal which has itself a stronger effect than a protidic one. Fibres eventually increase by 40 to 50 per cent the duration of the post-prandial continuous motor activity in the duodenum, and have, depending on their nature, a variable effect on the jejunum. Digestion and absorption of nutrients also appear to be involved through probable nervous and/or hormonal pathways. In animals, an increased absorption of lipids by addition of bile lengthens the inhibition duration; in man intravenous infusion of a lipidic emulsion can induce a typical post-prandial motor profile. Clinical implications of these results involve at the moment a hypothesis on the physiopathology of diarrhea and artificial, enteral or parenteral, nutrition. On the model of vagotomised patients, it was shown that diarrheic patients exhibited a shorter post-prandial activity. Enteral feeding can interrupt phase 3 on the one hand temporarily and on the other under the conditions of a minimal caloric flow and molecular weight of peptides in case of protidic infusion. Preliminary results with parenteral alimentation were found to be similar, with in particular a strong inhibitory effect of perfusion of lipids. PMID:2522222

  20. 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

  1. 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

  2. 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.

  3. Simulation of the direct production of 99mTc at a small cyclotron

    NASA Astrophysics Data System (ADS)

    Eslami, M.; Kakavand, T.

    2014-06-01

    Usually 99mTc is produced indirectly through generator 99Mo/99mTc. In the present study, the direct production of this radioisotope by charged particle irradiation was investigated using Monte Carlo method. After scouting of the reactions that produce 99mTc, excitation functions of these reactions were predicted by optical model components in the TALYS-1.6 code. Suitable energy range of projectile for this production was selected by spotting of maximum cross section and minimum impurity due to other emission channels. Then target geometry was designed based on stopping power calculation by the SRIM code. Thick target yield of 100Mo(p,2n)99mTc, 98Mo(p,?)99mTc and natMo(p,x)99mTc reactions was predicted by the result of excitation function and stopping power calculations. Finally, 100Mo(p,2n)99mTc reaction was selected as a primary reaction for the direct production of 99mTc and its process was simulated by employing the MCNPX code to calculate the energy distribution of proton in the 100Mo target body and estimation of residual nuclei during irradiation. Good agreement was obtained between the experimental, the theoretical, and the simulation-based (analytical and directly) production yields. This study demonstrated that Monte Carlo provides a method for the design and optimization of targets for the radionuclide production purposes.

  4. 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.

  5. 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…

  6. 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.

  7. Size-independent age effects on reproductive effort in a small, short-lived fish

    E-print Network

    García-Berthou, Emili

    Size-independent age effects on reproductive effort in a small, short-lived fish PABLO A. TEDESCO-independent age effect on reproductive effort was predicted based on previous studies of mosquitofish) and when the effect of size is removed, the effect of age on fecundity may be small or inconsistent

  8. Performance of a GPU-based Direct Summation Algorithm for Computation of Small Angle Scattering Profile

    E-print Network

    Berlin, Konstantin; Duraiswami, Ramani; Fushman, David

    2013-01-01

    Small Angle Scattering (SAS) of X-rays or neutrons is an experimental technique that provides valuable structural information for biological macromolecules under physiological conditions and with no limitation on the molecular size. In order to refine molecular structure against experimental SAS data, ab initio prediction of the scattering profile must be recomputed hundreds of thousands of times, which involves the computation of the sinc kernel over all pairs of atoms in a molecule. The quadratic computational complexity of predicting the SAS profile limits the size of the molecules and and has been a major impediment for integration of SAS data into structure refinement protocols. In order to significantly speed up prediction of the SAS profile we present a general purpose graphical processing unit (GPU) algorithm, written in OpenCL, for the summation of the sinc kernel (Debye summation) over all pairs of atoms. This program is an order of magnitude faster than a parallel CPU algorithm, and faster than an ...

  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 Effect of Zinc on Mitochondrial Apoptogenesis in Prostate Cells

    PubMed Central

    Feng, Pei; Li, Tie-Luo; Guan, Zhi-Xin; Franklin, Renty B.; Costello, Leslie C.

    2015-01-01

    BACKGROUND Prostate epithelial cells uniquely accumulate significantly higher levels of zinc than other mammalian cells. We previously showed that the accumulation of high intracellular zinc levels in specific prostate cells results in the induction of apoptosis and the inhibition of cell growth. The apoptotic effect is due to zinc induction of mitochondrial apoptogenesis. We now report additional studies that corroborate this effect of zinc and provide insight into the mechanism of this unique effect. METHODS The effect of exposure to physiological levels of zinc on apoptosis was determined for three human prostate cell lines (PC-3, BPH, and HPR-1). Zinc-induced apoptosis was identified by DNA fragmentation. The direct effect of zinc on isolated mitochondrial preparations from each cell line was determined. The mitochondrial release of cytochrome c was determined by Western blot. RESULTS Exposure to zinc induced apoptosis in PC-3 and BPH cells but not in HPR-1 cells. The zinc accumulation in PC-3 (4.3 ± 0.3) and BPH (2.8 ± 0.4) was higher than that in HPR-1 cells (1.8 ± 0.1). The apoptotic effect of zinc on PC-3 cells could be observed as early as 4–6 hr of zinc treatment, and this effect was not reversible. The exposure of isolated mitochondria from PC-3 and BPH cells to zinc resulted in the release of cytochrome c; but zinc had no effect on mitochondria from HPR-1 cells. CONCLUSIONS Exposure to zinc induces apoptosis in PC-3 and BPH cells, which accumulate high intracellular levels of zinc, but not in HPR-1 cells, which do not accumulate high levels of zinc. Once initiated, the induction of apoptosis is not reversed by the removal of zinc, i.e., it is an irreversible process. The apoptogenic effect is due to a direct effect of zinc on mitochondria that results in the release of cytochrome c. The cell specificity of zinc induction of apoptogenesis is dependent on the ability of the cells to accumulate high levels of intracellular zinc and on the ability of the mitochondria to respond to the direct effect of zinc. PMID:12210492

  11. Earth's Stopping Effect in Directional Dark Matter Detectors

    E-print Network

    Chris Kouvaris

    2015-09-29

    We explore the stopping effect that results from interactions between dark matter and nuclei as the dark matter particles travel undergound towards the detector. Although this effect is negligible for heavy dark matter particles, there is parameter phase space where the underground interactions of the dark matter particles with the nuclei can create observable differences in the spectrum. Dark matter particles that arrive on the detector from below can have less energy from the ones arriving from above. These differences can be potentially detectable by upcoming directional detectors. This can unveil a large amount of information regarding the type and strength of interactions between nuclei and light dark matter candidates.

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

    PubMed

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

    2012-09-01

    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. PMID:22878498

  13. 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 $N=152$.

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

    E-print Network

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

    2014-01-01

    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 $N=152$.

  15. Direct control of the small-scale energy balance in two-dimensional fluid dynamics

    NASA Astrophysics Data System (ADS)

    Frank, Jason; Leimkuhler, Benedict; Myerscough, Keith W.

    2015-11-01

    We explore the direct modification of the pseudo-spectral truncation of 2D, incompressible fluid dynamics to maintain a prescribed kinetic energy spectrum. The method provides a means of simulating fluid states with defined spectral properties, for the purpose of matching simulation statistics to given information, arising from observations, theoretical prediction or high fidelity simulation. In the scheme outlined here, Nos\\'e-Hoover thermostats, commonly used in molecular dynamics, are introduced as feedback controls applied to energy shells of the Fourier-discretized Navier-Stokes equations. As we demonstrate in numerical experiments, the dynamical properties (quantified using autocorrelation functions) are only modestly perturbed by our device, while ensemble dispersion is significantly enhanced in comparison with simulations of a corresponding truncation incorporating hyperviscosity.

  16. Small-molecule-directed, efficient generation of retinal pigment epithelium from human pluripotent stem cells.

    PubMed

    Maruotti, Julien; Sripathi, Srinivas R; Bharti, Kapil; Fuller, John; Wahlin, Karl J; Ranganathan, Vinod; Sluch, Valentin M; Berlinicke, Cynthia A; Davis, Janine; Kim, Catherine; Zhao, Lijun; Wan, Jun; Qian, Jiang; Corneo, Barbara; Temple, Sally; Dubey, Ramin; Olenyuk, Bogdan Z; Bhutto, Imran; Lutty, Gerard A; Zack, Donald J

    2015-09-01

    Age-related macular degeneration (AMD) is associated with dysfunction and death of retinal pigment epithelial (RPE) cells. Cell-based approaches using RPE-like cells derived from human pluripotent stem cells (hPSCs) are being developed for AMD treatment. However, most efficient RPE differentiation protocols rely on complex, stepwise treatments and addition of growth factors, whereas small-molecule-only approaches developed to date display reduced yields. To identify new compounds that promote RPE differentiation, we developed and performed a high-throughput quantitative PCR screen complemented by a novel orthogonal human induced pluripotent stem cell (hiPSC)-based RPE reporter assay. Chetomin, an inhibitor of hypoxia-inducible factors, was found to strongly increase RPE differentiation; combination with nicotinamide resulted in conversion of over one-half of the differentiating cells into RPE. Single passage of the whole culture yielded a highly pure hPSC-RPE cell population that displayed many of the morphological, molecular, and functional characteristics of native RPE. PMID:26269569

  17. Greenhouse Gas Sensing Using Small Unmanned Aerial Systems - Field Experiment Results and Future Directions

    NASA Astrophysics Data System (ADS)

    Aubrey, A. D.; Christensen, L. E.; Brockers, R.; Thompson, D. R.

    2014-12-01

    Requirements for greenhouse gas point source detection and quantification often require high spatial resolution on the order of meters. These applications, which help close the gap in emissions estimate uncertainties, also demand sensing with high sensitivity and in a fashion that accounts for spatiotemporal variability on the order of seconds to minutes. Low-cost vertical takeoff and landing (VTOL) small unmanned aerial systems (sUAS) provide a means to detect and identify the location of point source gas emissions while offering ease of deployment and high maneuverability. Our current fielded gas sensing sUAS platforms are able to provide instantaneous in situ concentration measurements at locations within line of sight of the operator. Recent results from field experiments demonstrating methane detection and plume characterization will be discussed here, including performance assessment conducted via a controlled release experiment in 2013. The logical extension of sUAS gas concentration measurement is quantification of flux rate. We will discuss the preliminary strategy for quantitative flux determination, including intrinsic challenges and heritage from airborne science campaigns, associated with this point source flux quantification. This system approach forms the basis for intelligent autonomous quantitative characterization of gas plumes, which holds great value for applications in commercial, regulatory, and safety environments.

  18. In vivo and in vitro toxicological effects of titanium dioxide nanoparticles on small intestine

    NASA Astrophysics Data System (ADS)

    Tassinari, Roberta; La Rocca, Cinzia; Stecca, Laura; Tait, Sabrina; De Berardis, Barbara; Ammendolia, Maria Grazia; Iosi, Francesca; Di Virgilio, Antonio; Martinelli, Andrea; Maranghi, Francesca

    2015-06-01

    In European Union, titanium dioxide (TiO2) as bulk material is a food additive (E171) and - as nanoparticle (NP) - is used as a white pigment in several products (e.g. food, cosmetics, drugs). E171 contains approximately 36% of particles less than 100 nm in at least one dimension and TiO2 NP exposure is estimated fairly below 2.5 mg/person/day. The gastrointestinal tract is a route of entry for NPs, thus representing a potential target of effects. In in vivo study, the effects of TiO2 NP in adult rat small intestine have been evaluated by oral administration of 0 (CTRL), 1 and 2 mg/kg body weight per day - relevant to human dietary intake. Detailed quali/quantitative histopathological analyses were performed on CTRL and treated rat samples. Scanning electron microscopy (SEM) analysis was performed on small intestine. An in vitro study on Caco-2 cells was also used in order to evaluate the potential cytotoxic effects directly on enterocytes through the lactate dehydrogenase (LDH) assay. Suspensions of TiO2 NPs for in vitro and in vivo study were characterized by EM. Histomorphometrical data showed treatment-related changes of villus height and widths in male rats. Significantly different from CTRL decreased LDH levels in the medium were detected in vitro at 24h with 2.5, 5, 10 and 20 µg/cm2 levels of TiO2 NPs. SEM analysis showed no damaged areas. Overall the results showed that enterocytes may represent a target of TiO2 NP toxicity by direct exposure both in vivo and in vitro models.

  19. 7SK small nuclear RNA directly affects HMGA1 function in transcription regulation

    PubMed Central

    Eilebrecht, Sebastian; Brysbaert, Guillaume; Wegert, Thomas; Urlaub, Henning; Benecke, Bernd-Joachim; Benecke, Arndt

    2011-01-01

    Non-coding (nc) RNAs are increasingly recognized to play important regulatory roles in eukaryotic gene expression. The highly abundant and essential 7SK ncRNA has been shown to negatively regulate RNA Polymerase II transcription by inactivating the positive transcription elongation factor b (P-TEFb) in cellular and Tat-dependent HIV transcription. Here, we identify a more general, P-TEFb-independent role of 7SK RNA in directly affecting the function of the architectural transcription factor and chromatin regulator HMGA1. An important regulatory role of 7SK RNA in HMGA1-dependent cell differentiation and proliferation regulation is uncovered with the identification of over 1500 7SK-responsive HMGA1 target genes. Elevated HMGA1 expression is observed in nearly every type of cancer making the use of a 7SK substructure in the inhibition of HMGA1 activity, as pioneered here, potentially useful in therapy. The 7SK-HMGA1 interaction not only adds an essential facet to the comprehension of transcriptional plasticity at the coupling of initiation and elongation, but also might provide a molecular link between HIV reprogramming of cellular gene expression-associated oncogenesis. PMID:21087998

  20. 7SK small nuclear RNA directly affects HMGA1 function in transcription regulation.

    PubMed

    Eilebrecht, Sebastian; Brysbaert, Guillaume; Wegert, Thomas; Urlaub, Henning; Benecke, Bernd-Joachim; Benecke, Arndt

    2011-03-01

    Non-coding (nc) RNAs are increasingly recognized to play important regulatory roles in eukaryotic gene expression. The highly abundant and essential 7SK ncRNA has been shown to negatively regulate RNA Polymerase II transcription by inactivating the positive transcription elongation factor b (P-TEFb) in cellular and Tat-dependent HIV transcription. Here, we identify a more general, P-TEFb-independent role of 7SK RNA in directly affecting the function of the architectural transcription factor and chromatin regulator HMGA1. An important regulatory role of 7SK RNA in HMGA1-dependent cell differentiation and proliferation regulation is uncovered with the identification of over 1500 7SK-responsive HMGA1 target genes. Elevated HMGA1 expression is observed in nearly every type of cancer making the use of a 7SK substructure in the inhibition of HMGA1 activity, as pioneered here, potentially useful in therapy. The 7SK-HMGA1 interaction not only adds an essential facet to the comprehension of transcriptional plasticity at the coupling of initiation and elongation, but also might provide a molecular link between HIV reprogramming of cellular gene expression-associated oncogenesis. PMID:21087998

  1. 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.

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

    E-print Network

    #12;SUITABILITY OF SMALL FISH SPECIES FOR MONITORING THE EFFECTS OF PULP MILL EFFLUENT ON FISH;SUITABILITY OF SMALL FISH SPECIES FOR MONITORING THE EFFECTS OF PULP MILL EFFLUENT ON FISH POPULATIONS of the elements of study included monitoring the effects of pulp mill effluent on resident fish populations

  3. 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.

  4. 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)

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

    E-print Network

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

    2015-06-22

    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.

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

    NASA Astrophysics Data System (ADS)

    Schneck, K.; Cabrera, B.; Cerdeño, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; 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.; Lopez Asamar, E.; Lukens, P.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; 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.; SuperCDMS Collaboration

    2015-05-01

    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.

  7. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Small electric motors energy conservation standards and their effective dates. 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation Standards § 431.446 Small electric...

  8. 26 CFR 1.1202-2 - Qualified small business stock; effect of redemptions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Qualified small business stock; effect of.... Stock acquired by a taxpayer is not qualified small business stock if, in one or more purchases during.... Stock is not qualified small business stock if, in one or more purchases during the 2-year...

  9. EFFECTS OF WATERSHED ALTERATION ON THE BROOK TROUT POPULATION OF A SMALL BLACK HILLS STREAM

    E-print Network

    EFFECTS OF WATERSHED ALTERATION ON THE BROOK TROUT POPULATION OF A SMALL BLACK HILLS STREAM Timothy and livestock presence on the brook trout (Salvelinus fontinalis) population of a small Black Hills stream were) population to water quality and habi- tat changes in a small Black Hills stream sub- jected to landscaping

  10. The effect of directivity in a PSHA framework

    NASA Astrophysics Data System (ADS)

    Spagnuolo, E.; Herrero, A.; Cultrera, G.

    2012-09-01

    We propose a method to introduce a refined representation of the ground motion in the framework of the Probabilistic Seismic Hazard Analysis (PSHA). This study is especially oriented to the incorporation of a priori information about source parameters, by focusing on the directivity effect and its influence on seismic hazard maps. Two strategies have been followed. One considers the seismic source as an extended source, and it is valid when the PSHA seismogenetic sources are represented as fault segments. We show that the incorporation of variables related to the directivity effect can lead to variations up to 20 per cent of the hazard level in case of dip-slip faults with uniform distribution of hypocentre location, in terms of spectral acceleration response at 5 s, exceeding probability of 10 per cent in 50 yr. The second one concerns the more general problem of the seismogenetic areas, where each point is a seismogenetic source having the same chance of enucleate a seismic event. In our proposition the point source is associated to the rupture-related parameters, defined using a statistical description. As an example, we consider a source point of an area characterized by strike-slip faulting style. With the introduction of the directivity correction the modulation of the hazard map reaches values up to 100 per cent (for strike-slip, unilateral faults). The introduction of directivity does not increase uniformly the hazard level, but acts more like a redistribution of the estimation that is consistent with the fault orientation. A general increase appears only when no a priori information is available. However, nowadays good a priori knowledge exists on style of faulting, dip and orientation of faults associated to the majority of the seismogenetic zones of the present seismic hazard maps. The percentage of variation obtained is strongly dependent on the type of model chosen to represent analytically the directivity effect. Therefore, it is our aim to emphasize more on the methodology following which, all the information collected may be easily converted to obtain a more comprehensive and meaningful probabilistic seismic hazard formulation.

  11. 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…

  12. Experimental studies of the direct flexoelectric effect in bone materials

    NASA Astrophysics Data System (ADS)

    Fu, John

    2010-03-01

    The piezoelectric effect in biological tissues has been attracting research interest due to the hypothesis that it may behave as a biological transducer, which can convert external stimuli into biologically-recognizable signals capable of controlling growth or resorptive processes. The piezoelectric effect in dried bone materials was first observed in 1957 [1]. A link between the effect and the adaptive response of bone cells was proposed in 1970 [2]. In this paper, we report our recent measurements on the direct flexoelectric effect in bone materials. Our specimens are both dried and wet bones. The origin of both piezoelectricity and flexoelectricity in bone may be ascribed to the crystalline alignment of the micelle of collagen molecules. The Curie group symmetries of the configuration of collagen fibres in the bone texture demonstrate the existence of both effects. However, our experimental results show that the piezoelectric responses in bone materials may be dominated by flexoelectricity at the micro and nano scales. Finally, we propose a link between the flexoelectric effect and bone spur (osteophyte). [1] E. Fukada and I. Yasuda, J. Phys. Soc. Jpn. 12, 1158 (1957). [2] A. Marino and R. Becker, Nature 228, 78 (1970).

  13. Direct effects of increasing carbon dioxide on vegetation

    SciTech Connect

    Strain, B R; Cure, J D

    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)

  14. Vascular endothelial growth factor directly stimulates tumour cell proliferation in non-small cell lung cancer

    PubMed Central

    DEVERY, AOIFE M.; WADEKAR, REKHA; BOKOBZA, SIVAN M.; WEBER, ANIKA M.; JIANG, YANYAN; RYAN, ANDERSON J.

    2015-01-01

    Vascular endothelial growth factor (VEGF) is a key stimulator of physiological and pathological angiogenesis. VEGF signals primarily through VEGF receptor 2 (VEGFR2), a receptor tyrosine kinase whose expression is found predominantly on endothelial cells. The purpose of this study was to determine the role of VEGFR2 expression in NSCLC cells. NSCLC cells and tissue sections were stained for VEGFR2 expression by immunohistochemistry (IHC). Immunoblotting and ELISA were used to determine the activation and inhibition of VEGFR2 and its downstream signalling pathways. Five-day proliferation assays were carried out in the presence or absence of VEGF. IHC analysis of NSCLC demonstrated tumour cell VEGFR2 expression in 20% of samples. Immunoblot analysis showed expression of VEGFR2 protein in 3/8 NSCLC cell lines that correlated with VEGFR2 mRNA expression levels. VEGF-dependent VEGFR2 activation was apparent in NSCLC cells, and was associated with increased tumor cell proliferation. Cediranib treatment or siRNA against VEGFR2 inhibited VEGF-dependent increases in cell proliferation. Inhibition of VEGFR2 tyrosine kinase activity using cediranib was more effective than inhibition of AKT (MK2206) or MEK (AZD6244) for overcoming VEGFR2-driven cell proliferation. VEGF treatment did not affect cell survival following treatment with radiation, cisplatin, docetaxel or gemcitabine. Our data suggest that a subset of NSCLC tumour cells express functional VEGFR2 which can act to promote VEGF-dependent tumour cell growth. In this tumour subset, therapies targeting VEGFR2 signalling, such as cediranib, have the potential to inhibit both tumour cell proliferation and angiogenesis. PMID:26179332

  15. 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

  16. 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

  17. The direct magnetoelectric effect in ferroelectric-ferromagnetic epitaxial heterostructures.

    PubMed

    Fina, I; Dix, N; Rebled, J M; Gemeiner, P; Martí, X; Peiró, F; Dkhil, B; Sánchez, F; Fàbrega, L; Fontcuberta, J

    2013-09-01

    Ferroelectric (FE) and ferromagnetic (FM) materials engineered in horizontal heterostructures allow interface-mediated magnetoelectric coupling. The so-called converse magnetoelectric effect (CME) has been already demonstrated by electric-field poling of the ferroelectric layers and subsequent modification of the magnetic state of adjacent ferromagnetic layers by strain effects and/or free-carrier density tuning. Here we focus on the direct magnetoelectric effect (DME) where the dielectric state of a ferroelectric thin film is modified by a magnetic field. Ferroelectric BaTiO3 (BTO) and ferromagnetic CoFe2O4 (CFO) oxide thin films have been used to create epitaxial FE/FM and FM/FE heterostructures on SrTiO3(001) substrates buffered with metallic SrRuO3. It will be shown that large ferroelectric polarization and DME can be obtained by appropriate selection of the stacking order of the FE and FM films and their relative thicknesses. The dielectric permittivity, at the structural transitions of BTO, is strongly modified (up to 36%) when measurements are performed under a magnetic field. Due to the insulating nature of the ferromagnetic layer and the concomitant absence of the electric-field effect, the observed DME effect solely results from the magnetostrictive response of CFO elastically coupled to the BTO layer. These findings show that appropriate architecture and materials selection allow overcoming substrate-induced clamping in multiferroic multi-layered films. PMID:23872985

  18. MicroRNAs: small RNAs with big effects.

    PubMed

    Anglicheau, Dany; Muthukumar, Thangamani; Suthanthiran, Manikkam

    2010-07-27

    MicroRNAs (miRNAs) are evolutionarily conserved, small ( approximately 20-25 nucleotides), single-stranded molecules that suppress the expression of protein-coding genes by translational repression, messenger RNA degradation, or both. More than 700 miRNAs have been identified in the human genome. Amazingly, a single miRNA can regulate the expression of hundreds of mRNAs or proteins within a cell. The small RNAs are fast emerging as master regulators of innate and adaptive immunity and likely to play a pivotal role in transplantation. The clinical application of RNA sequencing ("next-generation sequencing") should facilitate transcriptome profiling at an unprecedented resolution. We provide an overview of miRNA biology and their hypothesized roles in transplantation. PMID:20574417

  19. 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.

  20. An effective plasma membrane proteomics approach for small tissue samples

    PubMed Central

    Smolders, Katrien; Lombaert, Nathalie; Valkenborg, Dirk; Baggerman, Geert; Arckens, Lutgarde

    2015-01-01

    Advancing the quest for new drug targets demands the development of innovative plasma membrane proteome research strategies applicable to small, functionally defined tissue samples. Biotinylation of acute tissue slices and streptavidin pull-down followed by shotgun proteomics allowed the selective extraction and identification of >1,600 proteins of which >60% are associated with the plasma membrane, including (G-protein coupled) receptors, ion channels and transporters, and this from mm3-scale tissue. PMID:26047021

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

    NASA Astrophysics Data System (ADS)

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

    1994-05-01

    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.

  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 effects of leptin on brown and white adipose tissue.

    PubMed

    Siegrist-Kaiser, C A; Pauli, V; Juge-Aubry, C E; Boss, O; Pernin, A; Chin, W W; Cusin, I; Rohner-Jeanrenaud, F; Burger, A G; Zapf, J; Meier, C A

    1997-12-01

    Leptin is thought to exert its actions on energy homeostasis through the long form of the leptin receptor (OB-Rb), which is present in the hypothalamus and in certain peripheral organs, including adipose tissue. In this study, we examined whether leptin has direct effects on the function of brown and white adipose tissue (BAT and WAT, respectively) at the metabolic and molecular levels. The chronic peripheral intravenous administration of leptin in vivo for 4 d resulted in a 1.6-fold increase in the in vivo glucose utilization index of BAT, whereas no significant change was found after intracerebroventricular administration compared with pair-fed control rats, compatible with a direct effect of leptin on BAT. The effect of leptin on WAT fat pads from lean Zucker Fa/ fa rats was assessed ex vivo, where a 9- and 16-fold increase in the rate of lipolysis was observed after 2 h of exposure to 0.1 and 10 nM leptin, respectively. In contrast, no increase in lipolysis was observed in the fat pads from obese fa/fa rats, which harbor an inactivating mutation in the OB-Rb. At the level of gene expression, leptin treatment for 24 h increased malic enzyme and lipoprotein lipase RNA 1.8+/-0.17 and 1.9+/-0.14-fold, respectively, while aP2 mRNA levels were unaltered in primary cultures of brown adipocytes from lean Fa/fa rats. Importantly, however, no significant effect of leptin was observed on these genes in brown adipocytes from obese fa/fa animals. The presence of OB-Rb receptors in adipose tissue was substantiated by the detection of its transcripts by RT-PCR, and leptin treatment in vivo and in vitro activated the specific STATs implicated in the signaling pathway of the OB-Rb. Taken together, our data strongly suggest that leptin has direct effects on BAT and WAT, resulting in the activation of the Jak/STAT pathway and the increased expression of certain target genes, which may partially account for the observed increase in glucose utilization and lipolysis in leptin-treated adipose tissue. PMID:9389752

  4. Direct effects of leptin on brown and white adipose tissue.

    PubMed Central

    Siegrist-Kaiser, C A; Pauli, V; Juge-Aubry, C E; Boss, O; Pernin, A; Chin, W W; Cusin, I; Rohner-Jeanrenaud, F; Burger, A G; Zapf, J; Meier, C A

    1997-01-01

    Leptin is thought to exert its actions on energy homeostasis through the long form of the leptin receptor (OB-Rb), which is present in the hypothalamus and in certain peripheral organs, including adipose tissue. In this study, we examined whether leptin has direct effects on the function of brown and white adipose tissue (BAT and WAT, respectively) at the metabolic and molecular levels. The chronic peripheral intravenous administration of leptin in vivo for 4 d resulted in a 1.6-fold increase in the in vivo glucose utilization index of BAT, whereas no significant change was found after intracerebroventricular administration compared with pair-fed control rats, compatible with a direct effect of leptin on BAT. The effect of leptin on WAT fat pads from lean Zucker Fa/ fa rats was assessed ex vivo, where a 9- and 16-fold increase in the rate of lipolysis was observed after 2 h of exposure to 0.1 and 10 nM leptin, respectively. In contrast, no increase in lipolysis was observed in the fat pads from obese fa/fa rats, which harbor an inactivating mutation in the OB-Rb. At the level of gene expression, leptin treatment for 24 h increased malic enzyme and lipoprotein lipase RNA 1.8+/-0.17 and 1.9+/-0.14-fold, respectively, while aP2 mRNA levels were unaltered in primary cultures of brown adipocytes from lean Fa/fa rats. Importantly, however, no significant effect of leptin was observed on these genes in brown adipocytes from obese fa/fa animals. The presence of OB-Rb receptors in adipose tissue was substantiated by the detection of its transcripts by RT-PCR, and leptin treatment in vivo and in vitro activated the specific STATs implicated in the signaling pathway of the OB-Rb. Taken together, our data strongly suggest that leptin has direct effects on BAT and WAT, resulting in the activation of the Jak/STAT pathway and the increased expression of certain target genes, which may partially account for the observed increase in glucose utilization and lipolysis in leptin-treated adipose tissue. PMID:9389752

  5. 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

  6. 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…

  7. An Effective Approach for NRSFM of Small-Size Image Sequences

    PubMed Central

    Wang, Ya-Ping; Sun, Zhan-Li; Lam, Kin-Man

    2015-01-01

    In recent years, non-rigid structure from motion (NRSFM) has become one of the hottest issues in computer vision due to its wide applications. In practice, the number of available high-quality images may be limited in many cases. Under such a condition, the performances may not be satisfactory when existing NRSFM algorithms are applied directly to estimate the 3D coordinates of a small-size image sequence. In this paper, a sub-sequence-based integrated algorithm is proposed to deal with the NRSFM problem with small sequence sizes. In the proposed method, sub-sequences are first extracted from the original sequence. In order to obtain diversified estimations, multiple weaker estimators are constructed by applying the extracted sub-sequences to a recent NRSFM algorithm with a rotation-invariant kernel (RIK). Compared to other first-order statistics, the trimmed mean is a relatively robust statistic. Considering the fact that the estimations of some weaker estimators may have large errors, the trimmed means of the outputs for all the weaker estimators are computed to determine the final estimated 3D shapes. Compared to some existing methods, the proposed algorithm can achieve a higher estimation accuracy, and has better robustness. Experimental results on several widely used image sequences demonstrate the effectiveness and feasibility of the proposed algorithm. PMID:26161521

  8. 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

  9. 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

  10. 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

  11. 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

  12. Effect of occlusion, directionality and age on horizontal localization

    NASA Astrophysics Data System (ADS)

    Alworth, Lynzee Nicole

    Localization acuity of a given listener is dependent upon the ability discriminate between interaural time and level disparities. Interaural time differences are encoded by low frequency information whereas interaural level differences are encoded by high frequency information. Much research has examined effects of hearing aid microphone technologies and occlusion separately and prior studies have not evaluated age as a factor in localization acuity. Open-fit hearing instruments provide new earmold technologies and varying microphone capabilities; however, these instruments have yet to be evaluated with regard to horizontal localization acuity. Thus, the purpose of this study is to examine the effects of microphone configuration, type of dome in open-fit hearing instruments, and age on the horizontal localization ability of a given listener. Thirty adults participated in this study and were grouped based upon hearing sensitivity and age (young normal hearing, >50 years normal hearing, >50 hearing impaired). Each normal hearing participant completed one localization experiment (unaided/unamplified) where they listened to the stimulus "Baseball" and selected the point of origin. Hearing impaired listeners were fit with the same two receiver-in-the-ear hearing aids and same dome types, thus controlling for microphone technologies, type of dome, and fitting between trials. Hearing impaired listeners completed a total of 7 localization experiments (unaided/unamplified; open dome: omnidirectional, adaptive directional, fixed directional; micromold: omnidirectional, adaptive directional, fixed directional). Overall, results of this study indicate that age significantly affects horizontal localization ability as younger adult listeners with normal hearing made significantly fewer localization errors than older adult listeners with normal hearing. Also, results revealed a significant difference in performance between dome type; however, upon further examination was not significant. Therefore, results examining type of dome should be viewed with caution. Results examining microphone configuration and microphone configuration by dome type were not significant. Moreover, results evaluating performance relative to unaided (unamplified) were not significant. Taken together, these results suggest open-fit hearing instruments, regardless of microphone or dome type, do not degrade horizontal localization acuity within a given listener relative to their 'older aged' normal hearing counterparts in quiet environments.

  13. Effect of intestinal resection on human small bowel motility.

    PubMed Central

    Schmidt, T; Pfeiffer, A; Hackelsberger, N; Widmer, R; Meisel, C; Kaess, H

    1996-01-01

    BACKGROUND: Few data are available on adaptive changes of human small bowel motility after intestinal resection. AIM: To characterise jejunal motility after extensive and limited distal intestinal resection. METHODS: Seven patients with a short bowel syndrome after total ileal and partial jejunal resection (residual jejunal segments between 60 and 100 cm) and six patients with limited distal ileal resection (resected segment between 30 and 70 cm) underwent ambulatory 24 hour jejunal manometry 15 (6-24) months after the operation. Normal values were obtained from 50 healthy subjects. Fasting motility and the motor response to a 600 kcal solid meal were analysed visually and by a computer program. RESULTS: Limited ileal resection did not result in changed jejunal motility. After extensive distal resection, patients had a significantly shorter migrating motor complex (MMC) cycle and a significantly shorter duration of the postprandial motor response compared with controls (p < 0.005). Intestinal resection had no influence on jejunal contraction frequency and amplitude and did not lead to any abnormal motor pattern. CONCLUSION: Extensive distal resection of the small intestine produces distinct abnormalities of fasting and postprandial motility in the intestinal remnant. The shortening of digestive motility and the increased frequency of MMC cycling could contribute to malabsorption and diarrhoea in the short bowel syndrome. PMID:8984024

  14. Effects of thermal inflation on small scale density perturbations

    NASA Astrophysics Data System (ADS)

    Hong, Sungwook E.; Lee, Hyung-Joo; Lee, Young Jae; Stewart, Ewan D.; Zoe, Heeseung

    2015-06-01

    In cosmological scenarios with thermal inflation, extra eras of moduli matter domination, thermal inflation and flaton matter domination exist between primordial inflation and the radiation domination of Big Bang nucleosynthesis. During these eras, cosmological perturbations on small scales can enter and re-exit the horizon, modifying the power spectrum on those scales. The largest modified scale, kb, touches the horizon size when the expansion changes from deflation to inflation at the transition from moduli domination to thermal inflation. We analytically calculate the evolution of perturbations from moduli domination through thermal inflation and evaluate the curvature perturbation on the constant radiation density hypersurface at the end of thermal inflation to determine the late time curvature perturbation. Our resulting transfer function suppresses the power spectrum by a factor 0~ 5 at k gg kb, with kb corresponding to anywhere from megaparsec to subparsec scales depending on the parameters of thermal inflation. Thus, thermal inflation might be constrained or detected by small scale observations such as CMB distortions or 21cm hydrogen line observations.

  15. The direct magnetoelectric effect in ferroelectric-ferromagnetic epitaxial heterostructures

    NASA Astrophysics Data System (ADS)

    Fina, I.; Dix, N.; Rebled, J. M.; Gemeiner, P.; Martí, X.; Peiró, F.; Dkhil, B.; Sánchez, F.; Fàbrega, L.; Fontcuberta, J.

    2013-08-01

    Ferroelectric (FE) and ferromagnetic (FM) materials engineered in horizontal heterostructures allow interface-mediated magnetoelectric coupling. The so-called converse magnetoelectric effect (CME) has been already demonstrated by electric-field poling of the ferroelectric layers and subsequent modification of the magnetic state of adjacent ferromagnetic layers by strain effects and/or free-carrier density tuning. Here we focus on the direct magnetoelectric effect (DME) where the dielectric state of a ferroelectric thin film is modified by a magnetic field. Ferroelectric BaTiO3 (BTO) and ferromagnetic CoFe2O4 (CFO) oxide thin films have been used to create epitaxial FE/FM and FM/FE heterostructures on SrTiO3(001) substrates buffered with metallic SrRuO3. It will be shown that large ferroelectric polarization and DME can be obtained by appropriate selection of the stacking order of the FE and FM films and their relative thicknesses. The dielectric permittivity, at the structural transitions of BTO, is strongly modified (up to 36%) when measurements are performed under a magnetic field. Due to the insulating nature of the ferromagnetic layer and the concomitant absence of the electric-field effect, the observed DME effect solely results from the magnetostrictive response of CFO elastically coupled to the BTO layer. These findings show that appropriate architecture and materials selection allow overcoming substrate-induced clamping in multiferroic multi-layered films.Ferroelectric (FE) and ferromagnetic (FM) materials engineered in horizontal heterostructures allow interface-mediated magnetoelectric coupling. The so-called converse magnetoelectric effect (CME) has been already demonstrated by electric-field poling of the ferroelectric layers and subsequent modification of the magnetic state of adjacent ferromagnetic layers by strain effects and/or free-carrier density tuning. Here we focus on the direct magnetoelectric effect (DME) where the dielectric state of a ferroelectric thin film is modified by a magnetic field. Ferroelectric BaTiO3 (BTO) and ferromagnetic CoFe2O4 (CFO) oxide thin films have been used to create epitaxial FE/FM and FM/FE heterostructures on SrTiO3(001) substrates buffered with metallic SrRuO3. It will be shown that large ferroelectric polarization and DME can be obtained by appropriate selection of the stacking order of the FE and FM films and their relative thicknesses. The dielectric permittivity, at the structural transitions of BTO, is strongly modified (up to 36%) when measurements are performed under a magnetic field. Due to the insulating nature of the ferromagnetic layer and the concomitant absence of the electric-field effect, the observed DME effect solely results from the magnetostrictive response of CFO elastically coupled to the BTO layer. These findings show that appropriate architecture and materials selection allow overcoming substrate-induced clamping in multiferroic multi-layered films. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr01011b

  16. Differential effects of dopamine-directed treatments on cognition

    PubMed Central

    Ashby, F Gregory; Valentin, Vivian V; von Meer, Stella S

    2015-01-01

    Dopamine, a prominent neuromodulator, is implicated in many neuropsychiatric disorders. It has wide-ranging effects on both cortical and subcortical brain regions and on many types of cognitive tasks that rely on a variety of different learning and memory systems. As neuroscience and behavioral evidence for the existence of multiple memory systems and their corresponding neural networks accumulated, so did the notion that dopamine’s role is markedly different depending on which memory system is engaged. As a result, dopamine-directed treatments will have different effects on different types of cognitive behaviors. To predict what these effects will be, it is critical to understand: which memory system is mediating the behavior; the neural basis of the mediating memory system; the nature of the dopamine projections into that system; and the time course of dopamine after its release into the relevant brain regions. Consideration of these questions leads to different predictions for how changes in brain dopamine levels will affect automatic behaviors and behaviors mediated by declarative, procedural, and perceptual representation memory systems. PMID:26251602

  17. Direct numerical simulation of Coriolis effects on cylindrical gravity currents

    NASA Astrophysics Data System (ADS)

    Cantero, Mariano; Salinas, Jorge; Bonometti, Thomas; Dari, Enzo

    2013-11-01

    Gravity currents are generated by the action of gravity (or other volumetric force) on changes in fluid density. When they appear in turbulent regime, gravity currents are of a non-linear nature and have a wide range of temporal and spatial scales. In these systems there is a strong coupling between turbulence and stratification effects, with important consequences in the exchange of mass, momentum and energy. At geophysical scale, the analysis of these type of flows is further complicated by the influence of rotation effects by the Coriolis forces originated by earth's rotation. In this work we address the rotational effects in gravity currents with cylindrical initial condition by means of direct numerical simulations (DNS). We report results on five three dimensional DNS with grid resolutions up to 166-million points, with different boundary conditions, Reynolds numbers (Re=4000 and Re=8000), and different conditions of rotation. The results focus mainly on the distance of propagation of the fronts, frequency of the successive outward fronts, and the turbulent structures present in the currents and their influence in flow dynamics. Support from CONICET, CNEA, ANPCyT, UPS and IMFT is greatly acknowledged.

  18. Direct effects of cattle on grassland birds in Canada.

    PubMed

    Bleho, Barbara I; Koper, Nicola; Machtans, Craig S

    2014-06-01

    Effects of grazing on grassland birds are generally thought to be indirect, through alteration of vegetation structure; however, livestock can also affect nest survival directly through trampling and other disturbances (e.g., livestock-induced abandonment). We extracted data on nest fates from 18 grazing studies conducted in Canada. We used these data to assess rates of nest destruction by cattle among 9 ecoregions and between seasonal and rotational grazing systems. Overall, few nests were destroyed by cattle (average 1.5% of 9132 nests). Nest destruction was positively correlated with grazing pressure (i.e., stocking rate or grazing intensity), but nest survival was higher in more heavily grazed areas for some species. Because rates of destruction of grassland bird nests by cattle are low in Canada, management efforts to reduce such destruction may not be of ecological or economic value in Canada. PMID:24617945

  19. Direct and indirect effects of climate change on amphibian populations

    USGS Publications Warehouse

    Blaustein, Andrew R.; Walls, Susan C.; Bancroft, Betsy A.; Lawler, Joshua J.; Searle, Catherine L.; Gervasi, Stephanie S.

    2010-01-01

    As part of an overall decline in biodiversity, populations of many organisms are declining and species are being lost at unprecedented rates around the world. This includes many populations and species of amphibians. Although numerous factors are affecting amphibian populations, we show potential direct and indirect effects of climate change on amphibians at the individual, population and community level. Shifts in amphibian ranges are predicted. Changes in climate may affect survival, growth, reproduction and dispersal capabilities. Moreover, climate change can alter amphibian habitats including vegetation, soil, and hydrology. Climate change can influence food availability, predator-prey relationships and competitive interactions which can alter community structure. Climate change can also alter pathogen-host dynamics and greatly influence how diseases are manifested. Changes in climate can interact with other stressors such as UV-B radiation and contaminants. The interactions among all these factors are complex and are probably driving some amphibian population declines and extinctions.

  20. QCD Effective action at high temperature and small chemical potential

    E-print Network

    C. Villavicencio; E. S. Fraga

    2006-08-14

    We present a construction of an effective Yang-Mills action for QCD, from the expansion of the fermionic determinant in terms of powers of the chemical potential at high temperature, for the case of massless quarks. We analyze this expansion in the perturbative region and find that it gives extra spurious information. We propose for the non-perturbative sector a simplified effective action which, in principle, contains only the relevant information.

  1. 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...

  2. 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.

  3. Wave and Wind Direction Effects on SFMR Brightness Temperatures

    NASA Astrophysics Data System (ADS)

    Holbach, Heather; Uhlhorn, Eric; Bourassa, Mark

    2015-04-01

    Surface winds in a tropical cyclone are essential for determining its strength. Currently the Stepped-Frequency Microwave Radiometer (SFMR) and Global Positioning System (GPS) dropwindsondes are the main instruments used for obtaining in situ surface wind measurements. The platforms for these instruments are the National Oceanographic and Atmospheric Administration (NOAA) P-3 and Air Force C-130J hurricane hunter aircraft. The SFMR measures sea surface microwave brightness temperatures at six frequencies ranging from 4.7 to 7.2 GHz. Surface wind speed estimates are obtained from these brightness temperatures by using a retrieval algorithm that employs a geophysical model function relating surface emissivity and wind speed. The SFMR is designed to obtain a single nadir track of surface wind speeds directly beneath the aircraft during level flight and not when turning because of the complexity of the wave field and foam distribution when the SFMR views the surface off-nadir or during aircraft rolls. However, the effects of the wave field on the measurements can be investigated using measurements obtained during the 2008 and 2014 Atlantic hurricane seasons. An SFMR module was flown in precipitation-free regions of the tropical cyclones to collect data at specified roll angles of 15°, 30°, 45°, and 60° in some cases. Excess brightness temperatures are then calculated with respect to zero wind speed values and independent of wind direction. An asymmetry is found in the resulting excess brightness temperatures. It is hypothesized that this asymmetry is caused by the direction of wave propagation and the angle at which the wave field is viewed by the SFMR. Wind direction may also play a role in the asymmetry. To analyze the asymmetry further measurement from WindSat will be used. Once the relationship is determined between surface wind speed, brightness temperature, and incidence angle a technique will be developed to obtain a surface wind speed when the aircraft is turning. This will begin to improve the spatial coverage of measurements of the tropical cyclone wind field to try to increase the probability that the maximum sustained wind speed within the tropical cyclone will be measured during the flight.

  4. Direct observation of finite size effects in chains of antiferromagnetically coupled spins

    PubMed Central

    Guidi, T.; Gillon, B.; Mason, S. A.; Garlatti, E.; Carretta, S.; Santini, P.; Stunault, A.; Caciuffo, R.; van Slageren, J.; Klemke, B.; Cousson, A.; Timco, G. A.; Winpenny, R. E. P.

    2015-01-01

    Finite spin chains made of few magnetic ions are the ultimate-size structures that can be engineered to perform spin manipulations for quantum information devices. Their spin structure is expected to show finite size effects and its knowledge is of great importance both for fundamental physics and applications. Until now a direct and quantitative measurement of the spatial distribution of the magnetization of such small structures has not been achieved even with the most advanced microscopic techniques. Here we present measurements of the spin density distribution of a finite chain of eight spin-3/2 ions using polarized neutron diffraction. The data reveal edge effects that are a consequence of the finite size and of the parity of the chain and indicate a noncollinear spin arrangement. This is in contrast with the uniform spin distribution observed in the parent closed chain and the collinear arrangement in odd-open chains. PMID:25952539

  5. 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.

  6. Small power plants; Seminar on Small Power Plants - Technology and Cost Effectiveness, Technische Universitaet Wien, Vienna, Austria, January 15, 16, 1981, Reports

    NASA Astrophysics Data System (ADS)

    Bauer, L.

    Progress in the production of small power plants is discussed. The topics considered include small power plants in Switzerland, the BRD, and Hungary, and the use of nontraditional energy sources in the USSR. The economic aspects of small power plants are examined, and direct and indirect means of producing solar energy are studied. The direct forms include the Austrian 10-kW plant, while the indirect forms discussed include water and wind power, biomass, hay, biogas, and wood. Unit power plants are discussed along with geothermal energy, heat pumps, the role of systems analysis, and the impact of energy production on the environment.

  7. Dry paths effectively reduce road mortality of small and medium-sized terrestrial vertebrates.

    PubMed

    Niemi, Milla; Jääskeläinen, Niina C; Nummi, Petri; Mäkelä, Tiina; Norrdahl, Kai

    2014-11-01

    Wildlife passages are widely used mitigation measures designed to reduce the adverse impacts of roads on animals. We investigated whether road kills of small and medium-sized terrestrial vertebrates can be reduced by constructing dry paths adjacent to streams that pass under road bridges. The study was carried out in southern Finland during the summer of 2008. We selected ten road bridges with dry paths and ten bridges without them, and an individual dry land reference site for each study bridge on the basis of landscape and traffic features. A total of 307 dead terrestrial vertebrates were identified during the ten-week study period. The presence of dry paths decreased the amount of road-killed terrestrial vertebrates (Poisson GLMM; p < 0.001). That was true also when considering amphibians alone (p < 0.001). The evidence on road-kills on mammals was not such clear. In the mammal model, a lack of dry paths increased the amount of carcasses (p = 0.001) whereas the number of casualties at dry path bridges was comparable with dry land reference sites. A direct comparison of the dead ratios suggests an average efficiency of 79% for the dry paths. When considering amphibians and mammals alone, the computed effectiveness was 88 and 70%, respectively. Our results demonstrate that dry paths under road bridges can effectively reduce road-kills of small and medium-sized terrestrial vertebrates, even without guiding fences. Dry paths seemed to especially benefit amphibians which are a threatened species group worldwide and known to suffer high traffic mortality. PMID:24921961

  8. Effective gene suppression using small interfering RNA in hard-to-transfect human T cells.

    PubMed

    Yin, Jiyi; Ma, Zhengyu; Selliah, Nithianandan; Shivers, Debra K; Cron, Randy Q; Finkel, Terri H

    2006-05-30

    RNA interference (RNAi) is an evolutionarily conserved cellular defense mechanism that protects cells from hostile genes and regulates the function of normal genes during growth and development. In this study, we established proof of principle of small interfering RNA (siRNA) silencing in hard-to-transfect human T cell lines and primary human CD4 T cells. We used public and in-house programs to design four siRNAs each for GFP, for our novel cellular gene HALP, and for their corresponding scrambled siRNA controls. We generated siRNA expression cassettes (SECs) by PCR and directly transfected the PCR products into T cells using amaxa Nucleofector technology. The most effective SECs were selected and cloned into a TA cloning vector and titered with their respective controls to increase transfection efficiency. Flow cytometry and fluorescence microscopy analyses were performed for GFP siRNAs, and Northern blot analysis was done to assess the HALP silencing effect. These experiments demonstrate that SECs are an excellent screening tool to identify siRNA sequences effective in silencing expression of genes of interest. The vector expressing the most effective siRNA robustly inhibited GFP expression (up to 92%) in the context of co-transfection in human T cell lines and primary CD4 T cells. The optimized siRNA for our endogenous cellular gene HALP also silenced its target RNA expression by more than 90%. These studies demonstrate that the combination of SEC, siRNA expression vectors and Nucleofector technology can be successfully applied to hard-to-transfect human T cell lines and primary T cells to effectively silence genes. PMID:16603179

  9. 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

  10. Antiobesity Effect of a Small Molecule Repressor of ROR?

    PubMed Central

    Chang, Mi Ra; He, Yuanjun; Khan, Tanya M.; Kuruvilla, Dana S.; Garcia-Ordonez, Ruben; Corzo, Cesar A.; Unger, Thaddeus J.; White, David W.; Khan, Susan; Lin, Li; Cameron, Michael D.; Kamenecka, Theodore M.

    2015-01-01

    The orphan nuclear receptor ROR? is a key regulator for T helper 17 (TH17) cell differentiation, which regulates metabolic and circadian rhythm genes in peripheral tissues. Previously, it was shown that the small molecule inverse agonist of ROR? SR1555 [1-(4-((4?-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)-[1,1?-biphenyl]-4-yl)methyl)piperazin-1-yl) ethanone] suppressed TH17 differentiation and stimulated induced T regulatory (iTreg) cells. Here, we show that treatment of cultured pre-adipocyctes with SR1555 represses the expression of ROR? while leading to increased expression of FGF21 and adipoQ. Chronic administration of SR1555 to obese diabetic mice resulted in a modest reduction in food intake accompanied with significant reduction in fat mass, resulting in reduced body weight and improved insulin sensitivity. Analysis ex vivo of treated mice demonstrates that SR1555 induced expression of the thermogenic gene program in fat depots. Further studies in cultured cells showed that SR1555 inhibited activation of hormone-sensitive lipase and increased fatty acid oxidation. Combined, these results suggest that pharmacological repression of ROR? may represent a strategy for treatment of obesity by increasing thermogenesis and fatty acid oxidation, while inhibition of hormone-sensitive lipase activity results in a reduction of serum free fatty acids, leading to improved peripheral insulin sensitivity. PMID:25904554

  11. Effect of geometry on magnetism in small antiferromagnetic clusters

    SciTech Connect

    Reddy, B.V.; Khanna, S.N. )

    1992-05-01

    The magnetic behavior of small clusters with antiferromagnetic interactions has been studied. The clusters are modeled as Ising spins located at the atomic sites, interacting via a nearest-neighbor antiferromagnetic coupling. The magnetic moments of these Ising clusters at various temperatures and magnetic fields have been calculated using Monte Carlo simulations. We have studied clusters having icosahedral and cuboctahedral arrangements and containing between 13 and 561 atoms. Our results show that the variation of magnetization with applied field and the temperature depends on the geometry of the clusters. For icosahedral clusters, the calculated behavior indicates that the clusters have free spins and behave as frustrated paramagnets. On the other hand, cuboctahedral clusters show well-defined ground states indicating that the finite size quenches the frustration inherent in the fcc lattice. We also show that the magnetization for a given cluster size depends on the cluster geometry. The theoretical predictions will be compared with recent measurements of the magnetic moment of the Cr{sub {ital n}} clusters.

  12. Irrigated small grain residue management effects on soil properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of straw removal from fields under irrigated wheat and barley on soil properties has become a potential concern in Idaho. The demand of straw for animal bedding and feed, and the potential development of cellulosic ethanol production will likely increase in the future. This paper revie...

  13. Effect of small cage guests on hydrogen bonding of tetrahydrofuran in binary structure II clathrate hydrates.

    PubMed

    Alavi, Saman; Ripmeester, John A

    2012-08-01

    Molecular dynamics simulations of the pure structure II tetrahydrofuran clathrate hydrate and binary structure II tetrahydrofuran clathrate hydrate with CO(2), CH(4), H(2)S, and Xe small cage guests are performed to study the effect of the shape, size, and intermolecular forces of the small cages guests on the structure and dynamics of the hydrate. The simulations show that the number and nature of the guest in the small cage affects the probability of hydrogen bonding of the tetrahydrofuran guest with the large cage water molecules. The effect on hydrogen bonding of tetrahydrofuran occurs despite the fact that the guests in the small cage do not themselves form hydrogen bonds with water. These results indicate that nearest neighbour guest-guest interactions (mediated through the water lattice framework) can affect the clathrate structure and stability. The implications of these subtle small guest effects on clathrate hydrate stability are discussed. PMID:22894376

  14. Renoprotective Effects of Direct Renin Inhibition in Glomerulonephritis

    PubMed Central

    Miyata, Kayoko; Satou, Ryousuke; Inui, Daisuke; Katsurada, Akemi; Seth, Dale; Davis, Allison; Urushihara, Maki; Kobori, Hiroyuki; Mitchell, Kenneth D.; Navar, L. Gabriel

    2013-01-01

    The development of glomerulonephritis causes glomerular injury and renal dysfunction and is thought to increase renin release thus activating the renin-angiotensin system (RAS). The aims of this study were to demonstrate activation of the intrarenal RAS and determine the effects of direct renin inhibition (DRI) on the progression of glomerulonephritis. Rats were treated with anti-Thy1.1 antibody with or without DRI, aliskiren (30 mg/kg/day). In the glomerulonephritic rats, protein, microalbumin excretion levels and urinary angiotensinogen excretion, glomerular expansion score, and intrarenal TGF-? and PAI-1 mRNA levels were augmented compared with control rats; however, hypertension was not observed in the glomerulonephritic rats and aliskiren treatment did not modify their blood pressure. The increases in urinary protein (94.7 ± 13.0 mg/day) and microalbumin (7.52 ± 2.6 mg/day) excretion were reduced by aliskiren (43.6 ± 4.5 mg/day of protein and 2.57 ± 0.7 mg/day of microalbumin). Furthermore, the progression of glomerular expansion and elevation of intrarenal TGF-? and PAI-1 levels were prevented by aliskiren. Importantly, aliskiren suppressed the augmentation of urinary angiotensinogen levels, the increased angiotensinogen expression in the kidneys and the increases in Ang II levels in renal medulla induced by the anti-Thy1.1 antibody. These results suggest that DRI with aliskiren prevents intrarenal RAS activation leading to mitigation of the development of glomerulonephritis. In addition, the renoprotective effects of DRI on glomerulonephritis occur in a blood pressure-independent manner. Accordingly, treatment with aliskiren may be an effective approach to treat glomerulonephritis as well as other intrarenal RAS associated kidney diseases. PMID:24165783

  15. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Small electric motors energy conservation standards and their effective dates. 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy...

  16. 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. 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy...

  17. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Small electric motors energy conservation standards and their effective dates. 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy...

  18. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Small electric motors energy conservation standards and their effective dates. 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy...

  19. 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…

  20. The Effect of Small Group Discussion on Cutoff Scores during Standard Setting

    ERIC Educational Resources Information Center

    Deunk, Marjolein I.; van Kuijk, Mechteld F.; Bosker, Roel J.

    2014-01-01

    Standard setting methods, like the Bookmark procedure, are used to assist education experts in formulating performance standards. Small group discussion is meant to help these experts in setting more reliable and valid cutoff scores. This study is an analysis of 15 small group discussions during two standards setting trajectories and their effect

  1. Assessing the Effects of Small School Size on Mathematics Achievement: A Propensity Score-Matching Approach

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Keesler, Venessa; Schneider, Barbara

    2008-01-01

    Background: Small schools have been promoted as an educational reform that is capable of improving student outcomes. However, a survey of the research on small schools indicates that much of the movement for decreasing school size is based primarily on correlational methods that do not control for selection effects in the data. In addition,…

  2. 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.

  3. Polydopamine-coated magnetic nanoparticles for enrichment and direct detection of small molecule pollutants coupled with MALDI-TOF-MS.

    PubMed

    Ma, Yu-rong; Zhang, Xiao-le; Zeng, Tao; Cao, Dong; Zhou, Zhen; Li, Wen-hui; Niu, Hongyun; Cai, Ya-qi

    2013-02-01

    Polydopamine-coated Fe(3)O(4) nanoparticles (Fe(3)O(4)@PDA NPs) were synthesized and applied as matrix for the detection of pollutants by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The synthesis of Fe(3)O(4)@PDA NPs was accomplished in 30 min by in situ polymerization of dopamine without any toxic reagent. Using Fe(3)O(4)@PDA NPs as matrix of MALDI-TOF, eleven small molecule pollutants (molecular weight from 251.6 to 499.3), including Benzo(a)pyrene (BaP), three perfluorinated compounds (PFCs), and seven antibiotics, were successfully detected in either positive or negative reflection mode without background interference. Furthermore, the Fe(3)O(4)@PDA NPs can also enrich trace amounts of hydrophobic target, such as BaP, from solution to nanoparticles surface. Then the Fe(3)O(4)@PDA-BaP can be isolated through magnetic sedimentation step and directly spotted on the stainless steel plate for MALDI measurement. With Fe(3)O(4)@PDA NPs as adsorbent and matrix, we also realized the analysis of BaP in tap water and lake water samples. Thus, a magnetic solid-phase extraction (MSPE)-MALDI-TOF-MS method was established for the measurement of BaP. PMID:23301525

  4. 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.

  5. Direct Determination of a Small-Molecule Drug, Valproic Acid, by an Electrically-Detected Microcantilever Biosensor for Personalized Diagnostics

    PubMed Central

    Huang, Long-Sun; Gunawan, Christian; Yen, Yi-Kuang; Chang, Kai-Fung

    2015-01-01

    Direct, small-molecule determination of the antiepileptic drug, valproic acid, was investigated by a label-free, nanomechanical biosensor. Valproic acid has long been used as an antiepileptic medication, which is administered through therapeutic drug monitoring and has a narrow therapeutic dosage range of 50–100 ?g·mL?1 in blood or serum. Unlike labeled and clinically-used measurement techniques, the label-free, electrical detection microcantilever biosensor can be miniaturized and simplified for use in portable or hand-held point-of-care platforms or personal diagnostic tools. A micromachined microcantilever sensor was packaged into the micro-channel of a fluidic system. The measurement of the antiepileptic drug, valproic acid, in phosphate-buffered saline and serum used a single free-standing, piezoresistive microcantilever biosensor in a thermally-controlled system. The measured surface stresses showed a profile over a concentration range of 50–500 ?g·mL?1, which covered the clinically therapeutic range of 50–100 ?g·mL?1. The estimated limit of detection (LOD) was calculated to be 45 ?g·mL?1, and the binding affinity between the drug and the antibody was measured at around 90 ± 21 ?g·mL?1. Lastly, the results of the proposed device showed a similar profile in valproic acid drug detection with those of the clinically-used fluorescence polarization immunoassay. PMID:25632826

  6. Rice Stripe Tenuivirus Nonstructural Protein 3 Hijacks the 26S Proteasome of the Small Brown Planthopper via Direct Interaction with Regulatory Particle Non-ATPase Subunit 3

    PubMed Central

    Xu, Yi; Wu, Jianxiang; Fu, Shuai; Li, Chenyang; Zhu, Zeng-Rong

    2015-01-01

    ABSTRACT The ubiquitin/26S proteasome system plays a vital role in regulating host defenses against pathogens. Previous studies have highlighted different roles for the ubiquitin/26S proteasome in defense during virus infection in both mammals and plants, but their role in the vectors that transmit those viruses is still unclear. In this study, we determined that the 26S proteasome is present in the small brown planthopper (SBPH) (Laodelphgax striatellus) and has components similar to those in plants and mammals. There was an increase in the accumulation of Rice stripe virus (RSV) in the transmitting vector SBPH after disrupting the 26S proteasome, indicating that the SBPH 26S proteasome plays a role in defense against RSV infection by regulating RSV accumulation. Yeast two-hybrid analysis determined that a subunit of the 26S proteasome, named RPN3, could interact with RSV NS3. Transient overexpression of RPN3 had no effect on the RNA silencing suppressor activity of RSV NS3. However, NS3 could inhibit the ability of SBPH rpn3 to complement an rpn3 mutation in yeast. Our findings also indicate that the direct interaction between RPN3 and NS3 was responsible for inhibiting the complementation ability of RPN3. In vivo, we found an accumulation of ubiquitinated protein in SBPH tissues where the RSV titer was high, and silencing of rpn3 resulted in malfunction of the SBPH proteasome-mediated proteolysis. Consequently, viruliferous SBPH in which RPN3 was repressed transmitted the virus more effectively as a result of higher accumulation of RSV. Our results suggest that the RSV NS3 protein is able to hijack the 26S proteasome in SBPH via a direct interaction with the RPN3 subunit to attenuate the host defense response. IMPORTANCE We show, for the first time, that the 26S proteasome components are present in the small brown planthopper and play a role in defense against its vectored plant virus (RSV). In turn, RSV encodes a protein that subverts the SBPH 26S proteasome via direct interaction with the 26S proteasome subunit RPN3. Our results imply that the molecular arms race observed in plant hosts can be extended to the insect vector that transmits those viruses. PMID:25653432

  7. 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

  8. 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…

  9. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...and their effective dates. [Reserved] 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy...

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

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...conservation standards and their effective dates. 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy...

  11. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...conservation standards and their effective dates. 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy...

  12. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...conservation standards and their effective dates. 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy...

  13. 10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...conservation standards and their effective dates. 431.446 Section 431.446 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy...

  14. 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.

  15. Tidal Effect in Small-Scale Sound Propagation Experiment

    NASA Astrophysics Data System (ADS)

    Kamimura, Seiji; Ogasawara, Hanako; Mori, Kazuyoshi; Nakamura, Toshiaki

    2012-07-01

    A sound propagation experiment in very shallow water was conducted at Hashirimizu port in 2009. We transmitted 5 kHz sinusoidal waves with M-sequence modulation. As a result, we found that the travel time concentrated in two time frames. When comparing the travel time with the tide level, the travel time was dependent on the tide level. In terms of the wave patterns, most of the wave patterns have two peaks. As the tide level changed, the biggest peak switched within two peaks. To discuss this, numerical simulation by finite difference time domain (FDTD) method was carried out. The result agreed with the experimental result. Finally, we changed the material of the quay wall in the FDTD simulation and concluded that the first peak is a multireflected combination wave and the effect of its reflected wave at a quay wall has superiority in the second peak.

  16. 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 efficiency (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

  17. 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.

  18. Direct Integration and Non-Perturbative Effects in Matrix Models

    E-print Network

    Albrecht Klemm; Marcos Marino; Marco Rauch

    2010-02-22

    We show how direct integration can be used to solve the closed amplitudes of multi-cut matrix models with polynomial potentials. In the case of the cubic matrix model, we give explicit expressions for the ring of non-holomorphic modular objects that are needed to express all closed matrix model amplitudes. This allows us to integrate the holomorphic anomaly equation up to holomorphic modular terms that we fix by the gap condition up to genus four. There is an one-dimensional submanifold of the moduli space in which the spectral curve becomes the Seiberg--Witten curve and the ring reduces to the non-holomorphic modular ring of the group $\\Gamma(2)$. On that submanifold, the gap conditions completely fix the holomorphic ambiguity and the model can be solved explicitly to very high genus. We use these results to make precision tests of the connection between the large order behavior of the 1/N expansion and non-perturbative effects due to instantons. Finally, we argue that a full understanding of the large genus asymptotics in the multi-cut case requires a new class of non-perturbative sectors in the matrix model.

  19. Direct measurement of Lorentz transformation with Doppler effects

    NASA Astrophysics Data System (ADS)

    Chen, Shao-Guang

    For space science and astronomy the fundamentality of one-way velocity of light (OWVL) is selfevident. The measurement of OWVL (distance/interval) and the clock synchronization with light-signal transfer make a logical circulation. This means that OWVL could not be directly measured but only come indirectly from astronomical method (Romer's Io eclipse and Bradley's sidereal aberration), furthermore, the light-year by definitional OWVL and the trigonometry distance with AU are also un-measurable. For to solve this problem two methods of clock synchronization were proposed: The direct method is that at one end of dual-speed transmissionline with single clock measure the arriving-time difference of longitudinal wave and transverse wave or ordinary light and extraordinary light, again to calculate the collective sending-time of two wave with Yang's /shear elastic-modulus ratio (E/k) or extraordinary/ordinary light refractive-index ratio (ne/no), which work as one earthquake-station with single clock measures first-shake time and the distance to epicenter; The indirect method is that the one-way wavelength l is measured by dual-counters Ca and Cb and computer's real-time operation of reading difference (Nb - Na) of two counters, the frequency f is also simultaneously measured, then l f is just OWVL. Therefore, with classical Newtonian mechanics and ether wave optics, OWVL can be measured in the Galileo coordinate system with an isotropic length unit (1889 international meter definition). Without any hypotheses special relativity can entirely establish on the metrical results. When a certain wavelength l is defined as length unit, foregoing measurement of one-way wavelength l will become as the measurement of rod's length. Let a rigidity-rod connecting Ca and Cb moves relative to lamp-house with velocity v, rod's length L = (Nb - Na) l will change follow v by known Doppler effect, i.e., L(q) =L0 (1+ (v/c) cos q), where L0 is the proper length when v= 0, v• r = v cos q, r is the unit vector from lamphouse point to counters. Or: L (0) L (pi) =L0 (1+(v/c)) L0 (1 - (v/c)) =L0 2 y2 =L2 Or: L ? [L(0)L(pi)]1/2 =L0 y , which y ? (1 - (v/c)2 )1/2 is just Fitzgerald-Lorentzian contraction-factor. Also, when a light-wave period p is defined as time unit, from Doppler's frequency-shift the count N with p of one period T of moving-clock is: T(q) = N(q) p = T0 /(1+(v/c) cos q) Or: T ? (T(0) T(pi))1/2 = T 0 /y , where T0 is the proper period when v = 0, which is just the moving-clock-slower effect. Let r from clock point to lamp-house ((v/c) symbol reverse), Doppler formula in the usual form is: f (q) = 1/T(q) = f0 (1 - (v/c) cos q). Therefore, Lorentz transformation is the square root average of positive and negative directions twice metrical results of Doppler's frequency-shift, which Doppler's once items ( positive and negative v/c ) are counteract only residual twice item (v/c)2 (relativity-factor). Then Lorentz transformation can be directly measured by Doppler's frequency-shift method. The half-life of moving mu-meson is statistical average of many particles, the usual explanation using relativity-factor y is correct. An airship moving simultaneously along contrary directions is impossible, which makes that the relativity-factor y and the twin-paradox are inexistent in the macroscopical movement. Thereby, in the navigations of airship or satellite only use the measurement of Doppler's frequency-shift but have no use for Lorentz transformation.

  20. 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…

  1. Physical and chemical effects of direct aqueous advanced oxidation processing on green sand foundry mold materials

    NASA Astrophysics Data System (ADS)

    Clobes, Jason Kenneth

    Iron foundries using the common green sand molding process have increasingly been incorporating aqueous advanced oxidation (AO) systems to reduce the consumption of sand system bentonite clay and coal raw materials by and to decrease their volatile organic compound (VOC) emissions. These AO systems typically use a combination of sonication, ozone aeration, and hydrogen peroxide to treat and recycle slurries of sand system baghouse dust, which is rich in clay and coal. While the overall effects of AO on raw material consumption and organic emissions are known, the mechanisms behind these effects are not well understood. This research examined the effects of bench-scale direct aqueous AO processing on green sand mold materials at the micro level. Bench-scale AO processing, including acoustic sonication, ozone/oxygen aeration, and hydrogen peroxide dramatically decreased the particle sizes of both western bentonite and foundry sand system baghouse dust. Bench-scale AO processing was shown to effectively separate the clay material from the larger silica and coal particles and to extensively break up the larger clay agglomerates. The acoustic sonication component of AO processing was the key contributor to enhanced clay recovery. Acoustic sonication alone was slightly more effective than combined component AO in reducing the particle sizes of the baghouse dust and in the recovery of clay yields in the supernatant during sedimentation experiments. Sedimentation separation results correlated well with the increase in small particle concentrations due to AO processing. Clay suspension viscosity decreased with AO processing due to enhanced dispersion of the particles. X-ray diffraction of freeze-dried baghouse dust indicated that AO processing does not rehydrate calcined montmorillonite and does not increase the level of interlayer water hydration in the dry clays. Zeta potential measurements indicated that AO processing also does not produce any large changes in the surface charge of the small clay particles upon AO treatment.

  2. The effect of compositionally-generated elastic stresses on morphological instability during directional solidification

    NASA Technical Reports Server (NTRS)

    Spencer, B. J.; Voorhees, P. W.; Davis, S. H.; Mcfadden, G. B.

    1992-01-01

    The effect of compositionally-generated elastic stresses on the conditions for morphological instability during directional solidification of a dilute, ideal binary alloy is investigated using the Gibbs-Thomson equations for an elastically-stressed solid with zero surface stress in equilibrium with a liquid. It is found that these stresses lead to a small stabilization of the Mullins and Sekerka cellular mode of instability. The steady mode is stabilized by a stress-induced modification to the interfacial concentration of the solid, which in turn alters the amount of solute rejected to inhibit the growth of perturbations. The presence of elastic stresses could generate a new oscillatory instability which is most likely to be found in experiments near absolute stability for materials with segregation coefficients near unity and large solute expansion coefficients.

  3. Effect of Directional Array Size on the Measurement of Airframe Noise Components

    NASA Technical Reports Server (NTRS)

    Brooks, Thomas F.; Humphreys, William M., Jr.

    1999-01-01

    A study was conducted to examine the effects of overall size of directional (or phased) arrays on the measurement of aeroacoustic components. An airframe model was mounted in the potential core of an open-jet windtunnel, with the directional arrays located outside the flow in an anechoic environment. Two array systems were used; one with a solid measurement angle that encompasses 31.6 deg.of source directivity and a smaller one that encompasses 7.2 deg. The arrays, and sub-arrays of various sizes, measured noise from a calibrator source and flap edge model setups. In these cases, noise was emitted from relatively small, but finite size source regions, with intense levels compared to other sources. Although the larger arrays revealed much more source region detail, the measured source levels were substantially reduced due to finer resolution compared to that of the smaller arrays. To better understand the measurements quantitatively, an analytical model was used to define the basic relationships between array to source region sizes and measured output level. Also, the effect of noise scattering by shear layer turbulence was examined using the present data and those of previous studies. Taken together, the two effects were sufficient to explain spectral level differences between arrays of different sizes. An important result of this study is that total (integrated) noise source levels are retrievable and the levels are independent of the array size as long as certain experimental and processing criteria are met. The criteria for both open and closed tunnels are discussed. The success of special purpose diagonal-removal processing in obtaining integrated results is apparently dependent in part on source distribution. Also discussed is the fact that extended sources are subject to substantial measurement error, especially for large arrays.

  4. Faithful Effective-One-Body waveforms of small-mass-ratio coalescing black-hole binaries

    E-print Network

    Thibault Damour; Alessandro Nagar

    2007-07-26

    We address the problem of constructing high-accuracy, faithful analytic waveforms describing the gravitational wave signal emitted by inspiralling and coalescing binary black holes. We work within the Effective-One-Body (EOB) framework and propose a methodology for improving the current (waveform)implementations of this framework based on understanding, element by element, the physics behind each feature of the waveform, and on systematically comparing various EOB-based waveforms with ``exact'' waveforms obtained by numerical relativity approaches. The present paper focuses on small-mass-ratio non-spinning binary systems, which can be conveniently studied by Regge-Wheeler-Zerilli-type methods. Our results include: (i) a resummed, 3PN-accurate description of the inspiral waveform, (ii) a better description of radiation reaction during the plunge, (iii) a refined analytic expression for the plunge waveform, (iv) an improved treatment of the matching between the plunge and ring-down waveforms. This improved implementation of the EOB approach allows us to construct complete analytic waveforms which exhibit a remarkable agreement with the ``exact'' ones in modulus, frequency and phase. In particular, the analytic and numerical waveforms stay in phase, during the whole process, within $\\pm 1.1 %$ of a cycle. We expect that the extension of our methodology to the comparable-mass case will be able to generate comparably accurate analytic waveforms of direct use for the ground-based network of interferometric detectors of gravitational waves.

  5. 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

  6. Effect of Beampattern on Directional Beacon based Position Location Algorithm for UWB Systems

    E-print Network

    Minnesota, University of

    Effect of Beampattern on Directional Beacon based Position Location Algorithm for UWB Systems S. F, we aim to evaluate the effect of antenna beampattern on the perfor- mance of directional beacon based components. Directional beacons are generated using four element uniform linear antenna array (ULA

  7. miR-215 functions as a tumor suppressor and directly targets ZEB2 in human non-small cell lung cancer

    PubMed Central

    HOU, YAN; ZHEN, JUNWEN; XU, XIAODONG; ZHEN, KUN; ZHU, BIN; PAN, RUI; ZHAO, CHIDONG

    2015-01-01

    MicroRNA-215 (miR-215) has previously been demonstrated to be dysregulated in a number of human malignancies and to be correlated with tumor progression. However, the expression and function of miR-215 in non-small cell lung cancer (NSCLC) has remained to be elucidated. Therefore, the present study aimed to investigate the effects of miR-215 in NSCLC tumorigenesis and development. Reverse transcription-quantitative polymerase chain reaction was used to evaluate miR-215 expression in NSCLC cell lines and primary tumor tissues. The association between miR-215 expression and certain clinicopathological factors was also determined, and the effects of miR-215 on the biological behavior of NSCLC cells were investigated. In addition, the potential regulatory function of miR-215 on zinc finger E-box-binding homeobox 2 (ZEB2) expression was examined. miR-215 expression was significantly downregulated in NSCLC cell lines and clinical specimens. Reduced miR-215 expression was significantly associated with lymph node metastasis and advanced TNM stage. Overexpression of miR-215 inhibited NSCLC cell proliferation, invasion and migration, and promoted cell apoptosis in vitro, and suppressed tumorigenicity in vivo. Furthermore, luciferase reporter assay analysis identified ZEB2 as a direct target of miR-215. These findings indicated that miR-215 may act as a tumor suppressor in NSCLC and may serve as a novel therapeutic agent for miR-based therapy.

  8. 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

  9. Direct and residual effects of manure on soil chemical properties

    NASA Astrophysics Data System (ADS)

    Nastri, A.; Triberti, L.; Giordani, G.; Comellini, F.; Baldoni, G.

    2009-04-01

    The beneficial effects of manure recycling in cropland on soil fertility are well documented. Nowadays it can help sequestrate C in the soil organic matter, advocated to mitigate the atmospheric CO2 increase. Because of the gradual disappearance of conventional livestock farming in Western Europe, the study of the persistence of the positive effects of manuring after its interruption can be interesting. Any research on soil fertility dynamic, however, requires long-term experiments because it is quite slow and greatly influenced by weather. A field trial, started in 1966 and still in progress in the Experimental Farm of Bologna University, compares 5 crop rotations (a 9-year course: corn-wheat-corn-wheat-corn-wheat-alfalfa-alfalfa-alfalfa, corn-wheat and sugarbeet-wheat, continuous corn and continuous wheat), at 3 levels of cattle manure supply combined with 3 inorganic NP fertilizers rates in a split-split plot replicated twice. The soil is an alluvial silty loam, fertile but low in organic matter (13.3 g kg-1). Manure is spread before corn, sugarbeet and alfalfa, at a mean yearly rate of 0 (M0), 20 (M1) and 40 (M2) t ha-1 of fresh material. Since 1984 M2 has been interrupted to evaluate residual effects. Regarding mineral fertilizer rates, for this study we considered only the unfertilized control (N0P0) and N1P1 level, corresponding to a mean yearly application of 220 kg N ha-1 and 75 kg P2O5 ha-1. Each year, since 1972 till now, we have sampled soil in the ploughed layer (0-0.4 m) to assess its pH (in water) and its content of organic carbon (SOC, Lotti method), total nitrogen (TN, Kjeldahl) and available phosphorus (P2O5, Olsen). To reduce the influence of crops and weather, statistical analyses were conducted on the averages of data obtained in the 4-year periods at the end of four 9-year cycles (1972-75, 81-84, 90-93 and 99-02). In 30 years, the continuous M1 supply without any inorganic integration increased SOC, TN and P2O5 by +3.6 t ha-1 (+11%), +1.09 t ha-1 (+ 29%) and + 166 kg ha-1 (+107%), respectively, compared to the control. These significant increments were obtained linearly, at mean annual rates of: 0.15 t ha-1 year-1 for SOC, 20 kg ha-1 for TN and 4.18 kg ha-1 for P2O5. During the first 18 years, doubling the manure supply (M2) caused further increments (72%, 76% and 112% increases for SOC, TN and P2O5, respectively, compared to M1). The complete interruption of M2 application, from 1984 onward, gradually decreased the positive effects. In the 1990-93 period, no differences between M1 and M2 were detected. After 18 years all the amounts were lower in M2 than in M1. However, a residual effect of the double manuring was still evident: M2 plots had higher SOC, TN and P2O5, contents compared to the unfertilized control (+3.1 t ha-1, +0.21 t ha-1 and +88 kg ha-1, respectively). Inorganic fertilization, in the absence of manure, did not affect SOC dynamic, whereas it had significant cumulative effects on TN (+0.94 t ha-1 (+26%) increase in the '99-02 period compared to the initial contents) and P2O5, with 223 kg ha-1 (+160%) increment. Treatments slightly influenced pH (6.43, on average): compared to the unfertilized control, manure increased it a little (+2.7%), while mineral fertilization had an opposite effect (-2.7%). In conclusion, the direct influences of manure on main components of soil fertility appeared cumulative with time and proportional to the application rates, at least up to 40 t ha-1 year-1 of fresh material. Residual effects gradually disappeared, but at low speed, thus their study requires really long experiments, lasting more than 20-years. Inorganic fertilization could increase nitrogen and, even more, available phosphorus content in the soil, but, in our research where crop residues are always removed, it had a null effect on SOC.

  10. 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 ...

  11. The effect of small gaps in California annual grassland on above-ground biomass production

    E-print Network

    Fehmi, Jeffrey S.

    The effect of small gaps in California annual grassland on above-ground biomass production J. S- mon in grasslands. In California annual grasslands, pat- ches of Lolium multi¯orum Lam. and Bromus resource use of these grasslands. The effect that differences in spatial aggre- gation, gap distribution

  12. Template-directed synthesis of a small molecule-antisense conjugate targeting an mRNA structure

    PubMed Central

    Liu, Yang; Rodriguez, Lilia; Wolfe, Michael S.

    2014-01-01

    The targeting of structural features in mRNA with specificity remains a great chemical challenge. A hairpin structure near exon 10 in the pre-mRNA encoding the tau protein controls its splicing, and dementia-causing mutations that disrupt this structure increase exon 10 splicing. We previously reported the discovery of small molecules, mitoxantrone (MTX) and analogs, which bind to the tau RNA hairpin structure and the design of bipartite antisense oligonucleotides (ASOs) that simultaneously bind to the discontinuous sequences that flank this hairpin. Herein we report the synthesis of a bipartite ASO conjugated to MTX using the tau RNA hairpin and flanking sequences as a template. A set of six MTX analogs, each containing a linker-azide, and a set of ten bipartite ASOs, each containing a branched linker-alkyne, were synthesized and tested in combinatorial fashion for their ability to conjugate in the presence or absence of template RNA. A single template-dependent MTX–ASO conjugate was identified from among the 60 reaction mixtures, demonstrating that the MTX and ASO precursors could simultaneously bind the RNA template and allow proper positioning of azide and alkyne for 1,3-cycloaddition. While the MTX–ASO conjugate proved too cytotoxic for cell-based assays, the conjugate inhibited tau exon 10 splicing under cell-free conditions more effectively than MTX or bipartite ASO alone. PMID:24691171

  13. Radiation sensitivity of small oocytes in immature mice. effect of gonadotropin treatment

    SciTech Connect

    Bager, S.

    1982-02-01

    The effect of pregnant mare serum gonadotropin on the survival of small oocytes of acutely irradiated immature mice was assessed by counting occytes on serial sections under the light microscope. Twenth-four hours after irradiation with 40 R the number of small oocytes was reduced to a few percent of that in unirradiated controls. The number of oocytes was a little higher in animals injected with gonadotropin before radiation exposure than in animals that were only irradiated. One week after radiation exposure very few small oocytes were seen in any of the irradiated ovaries regardless of treatment. Thus pregnant mare serum gonadotropin had no protective effect on the small oocytes of irradiated immature mice.

  14. Cellular effects of acute direct current stimulation: somatic and synaptic terminal effects

    PubMed Central

    Rahman, Asif; Reato, Davide; Arlotti, Mattia; Gasca, Fernando; Datta, Abhishek; Parra, Lucas C; Bikson, Marom

    2013-01-01

    Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique to modulate cortical excitability. Although increased/decreased excitability under the anode/cathode electrode is nominally associated with membrane depolarization/hyperpolarization, which cellular compartments (somas, dendrites, axons and their terminals) mediate changes in cortical excitability remains unaddressed. Here we consider the acute effects of DCS on excitatory synaptic efficacy. Using multi-scale computational models and rat cortical brain slices, we show the following. (1) Typical tDCS montages produce predominantly tangential (relative to the cortical surface) direction currents (4–12 times radial direction currents), even directly under electrodes. (2) Radial current flow (parallel to the somatodendritic axis) modulates synaptic efficacy consistent with somatic polarization, with depolarization facilitating synaptic efficacy. (3) Tangential current flow (perpendicular to the somatodendritic axis) modulates synaptic efficacy acutely (during stimulation) in an afferent pathway-specific manner that is consistent with terminal polarization, with hyperpolarization facilitating synaptic efficacy. (4) Maximal polarization during uniform DCS is expected at distal (the branch length is more than three times the membrane length constant) synaptic terminals, independent of and two–three times more susceptible than pyramidal neuron somas. We conclude that during acute DCS the cellular targets responsible for modulation of synaptic efficacy are concurrently somata and axon terminals, with the direction of cortical current flow determining the relative influence. PMID:23478132

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

    PubMed Central

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

    2014-01-01

    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 points To 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

  16. 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

  17. Understanding the Halogenation Effects in Diketopyrrolopyrrole-Based Small Molecule Photovoltaics.

    PubMed

    Sun, Shi-Xin; Huo, Yong; Li, Miao-Miao; Hu, Xiaowen; Zhang, Hai-Jun; Zhang, You-Wen; Zhang, You-Dan; Chen, Xiao-Long; Shi, Zi-Fa; Gong, Xiong; Chen, Yongsheng; Zhang, Hao-Li

    2015-09-16

    Two molecules containing a central diketopyrrolopyrrole and two oligothiophene units have been designed and synthesized. Comparisons between the molecules containing terminal F (FDPP) and Cl (CDPP) atoms allowed us to evaluate the effects of halogenation on the photovoltaic properties of the small molecule organic solar cells (OSCs). The OSCs devices employing FDPP:PC71BM films showed power conversion efficiencies up to 4.32%, suggesting that fluorination is an efficient method for constructing small molecules for OSCs. PMID:26261995

  18. Dark matter directional detection in non-relativistic effective theories

    NASA Astrophysics Data System (ADS)

    Catena, Riccardo

    2015-07-01

    We extend the formalism of dark matter directional detection to arbitrary one-body dark matter-nucleon interactions. The new theoretical framework generalizes the one currently used, which is based on 2 types of dark matter-nucleon interaction only. It includes 14 dark matter-nucleon interaction operators, 8 isotope-dependent nuclear response functions, and the Radon transform of the first 2 moments of the dark matter velocity distribution. We calculate the recoil energy spectra at dark matter directional detectors made of CF4, CS2 and 3He for the 14 dark matter-nucleon interactions, using nuclear response functions recently obtained through numerical nuclear structure calculations. We highlight the new features of the proposed theoretical framework, and present our results for a spherical dark matter halo and for a stream of dark matter particles. This study lays the foundations for model independent analyses of dark matter directional detection experiments.

  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. Small satellites

    NASA Technical Reports Server (NTRS)

    Thomas, P.; Veverka, J.; Dermott, S.

    1986-01-01

    Satellites smaller than Mimas (r = 195 km) are distinguished by irregular overall shapes and by rough limb topography. Material properties and impact cratering dominate the shaping of these objects. Long fragmentation histories can produce a variety of internal structures, but so far there is no direct evidence that any small satellite is an equilibrium ellipsoid made up of noncohesive gravitationally bound rubble. One many bodies that orbit close to their primary the tidal and rotational components of surface gravity strongly affect the directions of local g and thereby affect the redistribution of regolith by mass wasting. Downslope movement of regolith is extensive on Deimos, and is probably effective on many other small satellites. It is shown that in some cases observed patterns of downslope mass wasting cold produce useful constraints on the satellite's mean density. The diversity of features seen in the few high-resolution images of small satellites currently available suggests that these objects have undergone complex histories of cratering, fragmentation, and regolith evolution.

  1. 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…

  2. Direct Object Predictability: Effects on Young Children's Imitation of Sentences

    ERIC Educational Resources Information Center

    Valian, Virginia; Prasada, Sandeep; Scarpa, Jodi

    2006-01-01

    We hypothesize that the conceptual relation between a verb and its direct object can make a sentence easier ("the cat is eating some food") or harder ("the cat is eating a sock") to parse and understand. If children's limited performance systems contribute to the ungrammatical brevity of their speech, they should perform better on sentences that…

  3. Effects of Directed Written Disclosure on Grief and Distress Symptoms among Bereaved Individuals

    ERIC Educational Resources Information Center

    Lichtenthal, Wendy G.; Cruess, Dean G.

    2010-01-01

    Bereavement-specific written disclosure trials have generally demonstrated null effects, but these studies have not directed the focus of writing. This randomized controlled trial compared directed writing that focused on either sense-making or benefit-finding, both associated with adjustment to loss, to traditional, non-directed emotional…

  4. Complementary effects of gaze direction and early saliency in guiding fixations during free-viewing

    E-print Network

    Itti, Laurent

    Complementary effects of gaze direction and early saliency in guiding fixations during free, 3641 Watt Way, Los Angeles, CA 90089 Abstract Gaze direction provides an important and ubiquitous have addressed gaze direction in synthesized simple scenes, few have examined how it can bias observer

  5. Effects of corridors on home range sizes and interpatch movements of three small mammal species.

    SciTech Connect

    Mabry, Karen, E.; Barrett, Gary, W.

    2002-04-30

    Mabry, K.E., and G.W. Barrett. 2002. Effects of corridors on home range sizes and interpatch movements of three small mammal species. Landscape Ecol. 17:629-636. Corridors are predicted to benefit populations in patchy habitats by promoting movement, which should increase population densities, gene flow, and recolonization of extinct patch populations. However, few investigators have considered use of the total landscape, particularly the possibility of interpatch movement through matrix habitat, by small mammals. This study compares home range sizes of 3 species of small mammals, the cotton mouse, old field mouse and cotton rat between patches with and without corridors. Corridor presence did not have a statistically significant influence on average home range size. Habitat specialization and sex influenced the probability of an individual moving between 2 patches without corridors. The results of this study suggest that small mammals may be more capable of interpatch movement without corridors than is frequently assumed.

  6. Effect of experimental stress on the small bowel and colon in healthy humans

    PubMed Central

    Pritchard, SE; Garsed, KC; Hoad, CL; Lingaya, M; Banwait, R; Thongborisute, W; Roberts, E; Costigan, C; Marciani, L; Gowland, PA; Spiller, RC

    2015-01-01

    Background Symptoms of irritable bowel syndrome (IBS) are frequently reported to be exacerbated by stress. Animal studies suggest that corticotrophin releasing hormone (CRH) mediates the effect of stress on the bowel. We have shown that stressed IBS patients with diarrhea have constricted small bowels. We hypothesized that we could mimic this effect by applying experimental stress in the form of either hand immersion in ice water or CRH injection in healthy volunteers (HV). Methods The postprandial effect of the cold pressor test (repeated hand immersion in ice cold water) and injection of CRH, were assessed vs control in two groups of 18 HVs. Key Results CRH produced a significant rise from baseline salivary cortisol levels (p = 0.004) not seen with the cold pressor test. Small bowel water content (SBWC) fell postprandially on all four treatments. SBWC was significantly reduced by both stressors but CRH caused a greater effect (anova, p < 0.003 vs p = 0.02). Ascending colon (AC) volume was greater after CRH injection compared with saline (p = 0.002) but no differences were seen with the cold pressor test vs warm water. Postprandial increase in colon volume was also reduced by CRH which also increased the sensations of distension and bloating. Conclusions & Inferences Two experimental stressors were shown to constrict the small bowel, mimicking the effect previously seen in IBS-D patients. CRH increased the volume of the AC. We speculate that stress accelerates transfer of water from the small bowel to the AC. PMID:25703609

  7. 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

  8. Effects of dietary fat and fiber on the oxidative status of the small intestine and colon of rats 

    E-print Network

    Sanders, Lisa Merle

    2006-08-16

    DNA damage were greater in the colon than the small intestine. Thus the colon responds to oxidative stress less effectively than the small intestine, possibly contributing to increased cancer incidence at this site. We next wanted to understand how...

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

    E-print Network

    2015-01-01

    different dark matter masses, assuming an energy-indepen-States Department of Energy. DARK MATTER EFFECTIVE FIELDenergy spectrum from 100 simulated experiments (blue histogram) assuming the dark matter

  10. In vitro, antithrombotic and bleeding time studies of BMS-654457, a small-molecule, reversible and direct inhibitor of factor XIa.

    PubMed

    Wong, Pancras C; Quan, Mimi L; Watson, Carol A; Crain, Earl J; Harpel, Mark R; Rendina, Alan R; Luettgen, Joseph M; Wexler, Ruth R; Schumacher, William A; Seiffert, Dietmar A

    2015-11-01

    BMS-654457 ((+) 3'-(6-carbamimidoyl-4-methyl-4-phenyl-1,2,3,4-tetrahydro-quinolin-2-yl)-4-carbamoyl-5'-(3-methyl-butyrylamino)-biphenyl-2-carboxylic acid) is a small-molecule factor XIa (FXIa) inhibitor. We evaluated the in vitro properties of BMS-654457 and its in vivo activities in rabbit models of electrolytic-induced carotid arterial thrombosis and cuticle bleeding time (BT). Kinetic studies conducted in vitro with a chromogenic substrate demonstrated that BMS-654457 is a reversible and competitive inhibitor for FXIa. BMS-654457 increased activated partial thromboplastin time (aPTT) without changing prothrombin time. It was equipotent in prolonging the plasma aPTT in human and rabbit, and less potent in rat and dog. It did not alter platelet aggregation to ADP, arachidonic acid and collagen. In vivo, BMS-654457 or vehicle was given IV prior to initiation of thrombosis or cuticle transection. Preservation of integrated carotid blood flow over 90 min (iCBF, % control) was used as a marker of antithrombotic efficacy. BMS-654457 at 0.37 mg/kg + 0.27 mg/kg/h produced almost 90 % preservation of iCBF compared to its vehicle (87 ± 10 and 16 ± 3 %, respectively, n = 6 per group) and increased BT by 1.2 ± 0.04-fold (P < 0.05). At a higher dose (1.1 mg/kg + 0.8 mg/kg/h), BMS-654457 increased BT by 1.33 ± 0.08-fold. This compares favorably to equivalent antithrombotic doses of reference anticoagulants (warfarin and dabigatran) and antiplatelet agents (clopidogrel and prasugrel) which produced four- to six-fold BT increases in the same model. In summary, BMS-654457 was effective in the prevention of arterial thrombosis in rabbits with limited effects on BT. This study supports inhibition of FXIa, with a small-molecule, reversible and direct inhibitor as a promising antithrombotic therapy with a wide therapeutic window. PMID:26249722

  11. On the properties and radiative effects of small convective clouds during the eastern Mediterranean summer

    NASA Astrophysics Data System (ADS)

    Hirsch, Eitan; Koren, Ilan; Altaratz, Orit; Agassi, Eyal

    2015-04-01

    A ground-based field campaign was conducted over the summer of 2011 in Israel to measure the properties of small warm clouds. The horizontal size distribution for cloud sizes of 50-3000 m is presented, with a special focus on the properties of the smallest clouds (liquid water path <10 g m-2, cloud thickness < ˜50 m) and their estimated radiative effect. We show that these small clouds dominate the cloud radiative properties during the summer over the studied region. The average daily cloud cover of the small cloud subset throughout the field campaign was 81 ± 21% (corresponding to 30 ± 14.3% of the total measured time), and they contributed 83 ± 19.4% of the clouds' reflectance. Their average daily radiative effect was estimated at -3.6 ± 2.1 W m-2.

  12. 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

  13. 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…

  14. 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

  15. 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.

  16. Direct and indirect effects of experimental warming on ecosystem carbon processes in a tallgrass prairie

    E-print Network

    and indirect effects of experimental warming on ecosystem carbon processes in a tallgrass prairie, GlobalDirect and indirect effects of experimental warming on ecosystem carbon processes in a tallgrass 2005. [1] This study was conducted to examine direct and indirect impacts of global warming on carbon

  17. 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…

  18. 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/C.N.R.S., Villeneuve d'Ascq, France Among anthropogenic perturbations of the Earth's atmosphere, greenhouse gases. Besides the direct impact on radiation through the greenhouse effect and scattering of sunlight

  19. High School Teachers with Significant Teaching Experience Support the Effectiveness of Direct Instructional Strategies

    ERIC Educational Resources Information Center

    Nikolaros, John

    2014-01-01

    This research study was conducted to examine the effectiveness of direct instructional strategies regarding the achievement of students with ED. High school teachers with significant years of teaching experience in an urban setting support the effectiveness of direct instructional strategies. Teachers with 11-20 and 21-30 years of teaching…

  20. Target- and Effect-Directed Actions towards Temporal Goals: Similar Mechanisms?

    ERIC Educational Resources Information Center

    Walter, Andrea M.; Rieger, Martina

    2012-01-01

    The goal of an action can consist of generating a change in the environment (to produce an effect) or changing one's own situation in the environment (to move to a physical target). To investigate whether the mechanisms of effect-directed and target-directed action control are similar, participants performed continuous reversal movements. They…

  1. 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.

  2. The Entrance and Exit Effects in Small Electrochemical Filter-Press Reactors Used in the Laboratory

    ERIC Educational Resources Information Center

    Frias-Ferrer, Angel; Gonzalez-Garcia, Jose; Saez, Veronica; Exposito, Eduardo; Sanchez-Sanchez, Carlos M.; Mantiel, Vicente; Walsh, Frank C.; Aldaz, Antonio; Walsh, Frank C.

    2005-01-01

    A laboratory experiment designed to examine the entrance and exit effects in small electrochemical filter-press reactors used in the laboratory is presented. The single compartment of the filter-press reactor is filled with different turbulence promoters to study their influence as compared to the empty configuration.

  3. Small Group Learning with Games in Museums: Effects of Interactivity as Mediated by Cultural Differences

    E-print Network

    Small Group Learning with Games in Museums: Effects of Interactivity as Mediated by Cultural and complex learning experiences, using a variety of interactive approaches to engage their audiences. However that unrestricted visitor choice is a panacea to informal learning, as totally loose interaction with the museum

  4. COMMON SMALL GRAIN INSECTS For safe and effective use of insecticides, always identify the problem correctly.

    E-print Network

    Pittendrigh, Barry

    was a serious pest of wheat, but in recent years damage has been minimized by widespread use of resistantCOMMON SMALL GRAIN INSECTS For safe and effective use of insecticides, always identify the problem of the North Central States in cooperation with the Federal Extension Service, U.S. Department of Agriculture

  5. Color Filter Array Patterns Designed to Mitigate Crosstalk Effects in Small Pixel Image Sensors

    E-print Network

    Fossum, Eric R.

    Color Filter Array Patterns Designed to Mitigate Crosstalk Effects in Small Pixel Image Sensors Leo and CMY) are used. We present the design and analysis of new color filter array patterns for improving The design of CFA patterns is often discussed with regards to specifications such as spatial resolution

  6. English Reading Effects of Small-Group Intensive Intervention in Spanish for K-1 English Learners

    ERIC Educational Resources Information Center

    Gerber, Michael; Jimenez, Terese; Leafstedt, Jill; Villaruz, Jessica; Richards, Catherine; English, Judy

    2004-01-01

    In this article we report small, but statistically significant, effects of brief supplemental instruction on English reading by Spanish-speaking kindergartners (N=37) who performed poorly on a bilingual battery of phonological-processing tasks. Intervention design was compatible with the Reading First initiative and with research on use of…

  7. Quantitative analysis of the direct effect of aerosols over decadal scale by using ECHAM6-standalone

    NASA Astrophysics Data System (ADS)

    Muhammad, K.; Bott, A.; Hense, A.

    2013-12-01

    The influence of aerosols on climate is an important but still highly uncertain aspect in climate research. By using atmospheric general circulation model ECHAM6 our objective is to quantify the direct effect of aerosols over decadal time scale in comparison to the variability induced by the varying sea surface temperatures (SST) and sea ice concentrations (SIC) taken by the AMIP-II data base and the inevitable internal and unpredictable climate noise. We integrated the model with prescribed SST/SIC along with observed green house gases and aerosols concentrations for ten year period 1995-2004. Two ensembles with sample size ten, each have been created by starting the integrations on January 1st, 1995 with ten different initial conditions derived from two control runs over 15-years. These ensembles differ for tropospheric aerosols (TA): the non-aerosol case (NAC) is without any TA and aerosol case (AC) is utilizing a time variable data set of aerosols optical properties for input into the solar part of the ECHAM6 radiation code (Kinne et al, 2006). This set-up allows for a quantitative estimation and separation of the stationary and transient aerosol effects, the SST/SIC induced variability and the internal variability due to large scale atmospheric instabilities and non-linearities with the help of a two-way analysis of variance. We analyzed ensemble data for top of atmosphere (TOA) energy balance and temperature at 850 hPa. In the NAC, the ensemble exhibits a global and annual mean 3 W/m2 imbalance of the TOA radiation balance whereas the AC shows only 0.6 W/m2 being much closer in radiative balance over ten year period. The aerosols increase global planetary albedo from 0.29 (non-aerosol) to 0.30 for aerosol case. Extending the analysis to regional values of annual mean TOA radiation balance components, we find that the changes in TOA solar radiation budget are highly significant for static direct aerosol effect with local contributions to the total variability of up to 80% especially in North African-tropical Atlantic region. Transient aerosol and SST/SIC contributions to solar TOA radiative fluxes are of the order of 10%. Major contributor to the variability of TOA solar fluxes especially at mid-latitudes is internal variability also up to 80-90% outside the above mentioned regions. The results show that the direct effect of (prescribed) aerosols are clearly detectable even on a regional scale on decadal time scale if solar radiative fluxes are analyzed. The annual mean temperature at 850 hPa (dynamical variable) shows contrasting results. Major contributions of its variability at low latitudes come from SST (60-80% at tropical/subtropical latitudes) while the static aerosol effects are small (< 10% except in central equatorial Africa) and transient aerosol effects contribute up to 10% also at higher latitudes with the remaining part (locally 80-90%) coming from internal climate noise. In summary this analysis of variance of radiative fluxes and dynamical variables allows to draw objectively conclusions about the need to include (direct) aerosol effects into decadal climate forecasts. __________________________________________ Kinne. S and M. Schulz (2006). An AeroCom initial assessment-optical properties in aerosol component modules of global models: Atmos. Chem. Phys.,6,1815-1834

  8. Direct effects of audio-visual stimulation on EEG.

    PubMed

    Teplan, M; Krakovská, A; Stolc, S

    2011-04-01

    In the course of 2 months, 25 repetitions of a 20 min audio-visual stimulation (AVS) program with stimulations at 17, 9, 4, and 2 Hz were applied to 6 volunteers. EEG data were recorded from 6 scalp locations prior, during and after AVS. In order to identify direct and transient changes in EEG under influence of AVS, total power, relative frequency band powers and magnitude-squared coherences were estimated. Intense brain wave entrainment as a direct reaction to AVS was significant through increase of spectral powers and coherences around the stimulating frequency bands in the occipital areas, spreading also to the central and frontal regions. However, these excitations were 'short-lived'. On the other hand some signs of interhemispheric cooperation (coherences in the narrow bands around 2, 4, and 17 Hz at parieto-occipital areas) remained increased during the investigated 3 min after AVS. As going through further AVS sessions the driving response progressively enhanced for 2 and 4 Hz stimulation in centro-parietal locations. Progress was also found in the left and right hemisphere synchronization examined by coherences. In perspective, the results contribute to deeper comprehension of photic stimulation approaches as a technique of guided entrainment of the brain waves or intermediate increase of hemispheres' synchronization. PMID:21256616

  9. 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.

  10. Influence of Observed Diurnal Cycles of Aerosol Optical Depth on Aerosol Direct Radiative Effect

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    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 0.1-0.2W/sq m (both positive and negative) in absolute values, 5-10% in relative ones.

  11. Toxicological effects of particulate emissions - A comparison of oil and wood fuels in small- and medium-scale heating systems

    NASA Astrophysics Data System (ADS)

    Kasurinen, Stefanie; Jalava, Pasi I.; Tapanainen, Maija; Uski, Oskari; Happo, Mikko S.; Mäki-Paakkanen, Jorma; Lamberg, Heikki; Koponen, Hanna; Nuutinen, Ilpo; Kortelainen, Miika; Jokiniemi, Jorma; Hirvonen, Maija-Riitta

    2015-02-01

    The use of wood instead of oil fuels in heating systems is strongly encouraged in many countries. Yet it is unknown to what extent such a large-scale change from oil to wood fuels in heating systems would contribute to any negative health effects from their emissions. We compared the toxicological properties of particulate matter (PM) emissions from wood and oil fuels from two small-scale and two medium-scale heating systems. To assess whether oil or wood combustion emissions cause adverse effects and which PM emissions' effects are more profound, we measured cell viability and proliferation, inflammatory markers, as well as DNA damage in RAW264.7 mouse macrophages. We found that the medium-scale oil-fueled heating system induced a dose-dependent increase of DNA damage, short-term cytotoxic effects, and a cell cycle arrest in the G2/M-phase. We did not detect an induction of DNA damage by the medium-scale wood-fired system. However, we detected significant short-term cytotoxicity. We found that both oil and wood combustion emission samples from the small-scale heating systems induced DNA damage. However, the short-term cytotoxic effects were greater for the PM emissions from the oil-fired heating system. PM mass emissions differed significantly between the tested heating systems. The lowest emissions, 0.1 mg/MJ, were produced by the small-scale oil-fired heating system; the highest emissions, 20.3 mg/MJ, by the medium-scale oil-fired heating system. The wood-fired heating systems' PM mass emissions were in between these concentrations, complicating the direct comparison of the emissions' health related toxic effects. Conclusively, our results indicate that the emissions from both the small- and the medium-scale wood-fueled heating systems cause overall less cytotoxicity and DNA damage in a cell model than the emissions from the corresponding oil-fueled heating systems. Hence, controlled wood-fueled heating systems may be good alternatives to heating systems fired with fuel oil.

  12. Mapping Small Effect Mutations in Saccharomyces cerevisiae: Impacts of Experimental Design and Mutational Properties

    PubMed Central

    Duveau, Fabien; Metzger, Brian P. H.; Gruber, Jonathan D.; Mack, Katya; Sood, Natasha; Brooks, Tiffany E.; Wittkopp, Patricia J.

    2014-01-01

    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

  13. 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.

  14. The effects of small ice crystals on the infrared radiative properties of cirrus clouds

    NASA Technical Reports Server (NTRS)

    Takano, Y.; Liou, K. N.; Asano, S.; Heymsfield, A.; Minnis, P.

    1990-01-01

    The effects of nonspherical small ice crystals on the IR radiative properties of cirrus clouds are investigated utilizing light scattering properties of spheroidal particles. Employing the anomalous diffraction theory for spheres and results from the exact spheroid scattering program, efficient parameterization equations are developed for calculations of the absorption and scattering properties for small ice crystals. Parameterization formulas are developed for large ice crystals employing results computed from the geometric ray-tracing method and the Fraunhofer diffraction theory for hexagonal crystals and spheroids.

  15. Oxygen in GaAs - Direct and indirect effects

    NASA Technical Reports Server (NTRS)

    Gatos, H. C.; Skowronski, M.; Pawlowicz, L.; Lagowski, J.

    1984-01-01

    Oxygen has profound effects on the key electronic properties and point defects of GaAs crystals. Thus, when added in the growth system, it decreases the free electron concentration and enhances the concentration of deep donors in the resulting crystals. Both of these effects are highly beneficial for achieving semi-insulating material and have been utilized for that purpose. They have been attributed to the tendency of oxygen to getter silicon impurities during crystal growth. Only recently, it has been found that oxygen in GaAs introduces also a midgap level, ELO, with essentially the same activation energy as EL2 but with four times greater electron capture cross section. The present report reassesses the electrical and optical properties of the midgap levels in GaAs crystals grown by the horizontal Bridgman (HB) and the Czochralski-LEC techniques. Emphasis is placed on the identification of the specific effects of ELO.

  16. The effect of a small initial curvature on the free vibration of clamped, rectangular plates

    NASA Technical Reports Server (NTRS)

    Adeniji-Fashola, A. A.; Oyediran, A. A.

    1986-01-01

    An analytical method of obtaining the natural frequencies and mode shapes of clamped, rectangular plates having a small initial curvature is presented. Specifically, the singular perturbation technique is used to reduce the fourth-order plate vibration problem to the simpler membrane problem with modified boundary conditions that account for the bending effects. The eigenfrequencies for plates with inverse aspect ratios varying between 0.1 and 1.0 and for the dimensionless normal prestress between 0.1 and 1.0 have been presented for values of epsilon, the normalized bending rigidity, ranging between 0.0010 and 0.2500. It is established that a small initial curvature has no effect on the frequency of vibration of the plate. However, its effect is manifested in the eigenmodes.

  17. Unsteady transonic small-disturbance theory including entropy and vorticity effects

    NASA Technical Reports Server (NTRS)

    Batina, John T.

    1988-01-01

    Modifications to unsteady transonic small disturbance theory to include entropy and vorticity effects are presented. The modifications were implemented in the CAP-TSD (Computational Aeroelasticity Program - Transonic Small Disturbance) code. The code permits the aeroelastic analysis of complete aircraft configurations in the flutter critical transonic speed range. Entropy and vorticity effects were incorporated within the solution procedure to more accurately analyze flows with strong shock waves. The modified code includes these effects while retaining the relative simplicity and cost efficiency of the TSD formulation. Detailed descriptions are presented of the entropy and vorticity modifications along with calculated results and comparisons which assess the modified theory. These results are in good agreement with parallel Euler calculations and with experimental data. Therefore, the present method now provides the aeroelastician with an affordable capability to analyze relatively difficult transonic flows without having to solve the computationally more expensive Euler equations.

  18. Theory of the Effects of Small Gravitational Levels on Droplet Gasification

    NASA Technical Reports Server (NTRS)

    Beitelmal, A.; Shaw, B. D.

    1995-01-01

    A mathematical model taking into account small (and constant) gravitational levels is developed for vaporization of an isolated liquid droplet suspended in a stagnant atmosphere. A goal of the present analysis is to see how small gravitational levels affect droplet gasification characteristics. Attention is focused upon determining the effects on gas-phase phenomena. The conservation equations arc normalized and nondimensionalized, and a small parameter that accounts for the effects of gravity is identified. This parameter is the square of the inverse of a Froude number based on the gravitational acceleration, the droplet radius, and a characteristic gas-phase velocity at the droplet surface. Asymptotic analyses are developed in terms of this parameter. In the analyses, different spatial regions are identified. Near a droplet, gravitational effects are negligible in the first approximation, and the flowfield is spherically symmetric to the leading order. Analysis shows, however, that outer zones exist where gravitational effects cannot be neglected; it is expected that a stagnation point will be present in an outer zone that is not present when gravity is totally absent. The leading order and higher-order differential equations for each zone are derived and solved. The solutions allow the effects of gravity on vaporization rates and temperature, velocity and species fields to be determined.

  19. Effective Project Management of Small Satellite Projects from the System Engineer's Point of View, An Example of the Small Satellite Flying Laptop Project

    NASA Astrophysics Data System (ADS)

    Kuwahara, Toshinori; Falke, Albert; Röser, Hans-Peter

    The number of the small satellite projects is recently dramatically increasing and there are great demands for effective project management methods for them. The goal of this paper is to propose effective project management methods for small satellite projects, which are obtained through the real-life experience of the small satellite Flying Laptop project. The project management methods implemented in this project maximize the advantages of rapid and cost-effective small satellite approaches. The management of the project is based on project breakdown structures, which are derived from a combination of several existing standards and empirical methods. These management methods use a product tree as the backbone of the management architecture. The project management activities, such as the establishment of a work breakdown structure, drawing and documentation management structures, time scheduling, and cost management is described with real-life examples. Applications of project management tools, including open source software, which play important roles in cost-effective small satellite approaches, are also summarized and examples of them are illustrated. Finally, further possibilities of effective project management with up-coming new management tools are discussed.

  20. Aminoguanidine Alleviates Radiation-Induced Small-Bowel Damage Through Its Antioxidant Effect

    SciTech Connect

    Huang, E.-Y.; Wang, F.-S.; Lin, I-H.; Yang, Kuender D.

    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.

  1. Alternative Graphical Causal Models and the Identification of Direct Effects

    E-print Network

    for Statistics and the Social Sciences University of Washington 29 March, 2010 #12;Abstract We consider four conclude that the analysis provides strong evidence for "both an indirect effect of cigarette smoking and the statistical computer calculations performed on the strings of numbers has been obscure. Since the computer

  2. DRE Directions: What Makes an Effective Catechetical Leader?

    ERIC Educational Resources Information Center

    Walters, Thomas P.; Walters, Rita Tyson

    2003-01-01

    Discusses the top ten characteristics of effective Catechetical leaders: (1) prayerful/spiritual people; (2) passion for Catechetical Ministry; (3) creativity; (4) cooperative behavior; (5) active in professional organizations; (6) learns continuously; (7) respected by peers; (8) possesses administrative skills and run creative programs; (9)…

  3. A Homogenized Energy Model for the Direct Magnetomechanical Effect

    E-print Network

    - teretic induction Ban, remanent magnetization MR, remanent induction BR, and coercive field Hc, (ii to Man (equivalently B to Ban). 1.1 Stress-Dependence of Man, Ban, MR, BR and Hc The effect of stress-D. It is observed that as stresses are changed from +100 MPa to -400 MPa, Ban transitions from almost constant

  4. Effective Peer Assessment Processes: Research Findings and Future Directions

    ERIC Educational Resources Information Center

    van Zundert, Marjo; Sluijsmans, Dominique; van Merrienboer, Jeroen

    2010-01-01

    Despite the popularity of peer assessment (PA), gaps in the literature make it difficult to describe exactly what constitutes effective PA. In a literature review, we divided PA into variables and then investigated their interrelatedness. We found that (a) PA's psychometric qualities are improved by the training and experience of peer assessors;…

  5. 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…

  6. Post-Randomization Factors, Direct Effects and Randomized Trials

    E-print Network

    Chambaz, Antoine

    with diabetes mellitus. A randomized controlled trial," JAMA, 280, 1998, 1831-1836. · J. Simes, M. Voysey, R infections in Control Arm · ITT estimate of Relative Risk is 1.05 with a 95% CI of (0.84, 1.30) · End is the effectiveness of providing study product in environment of country-level standard condom counseling? (in

  7. 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

  8. 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.

  9. 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.

  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. Directly Observable Behavioral Effects of Lorcaserin in Rats

    PubMed Central

    Serafine, Katherine M.; Rice, Kenner C.

    2015-01-01

    (1R)-8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine (lorcaserin) is approved by the United States Food and Drug Administration for treating obesity, and its therapeutic effects are thought to result from agonist activity at serotonin (5-HT)2C receptors. Lorcaserin has affinity for other 5-HT receptor subtypes, although its activity at those subtypes is not fully described. The current study compared the behavioral effects of lorcaserin (0.0032–32.0 mg/kg) to the effects of other 5-HT receptor selective agonists in rats (n = 8). The 5-HT2C receptor selective agonist 1-(3-chlorophenyl)piperazine (mCPP, 0.032–1.0 mg/kg) and lorcaserin induced yawning which was attenuated by the 5-HT2C receptor selective antagonist 6-chloro-5-methyl-N-(6-[(2-methylpyridin-3-yl)oxy]pydidin-3-yl)indoline-1-carboxamide (1.0 mg/kg). The 5-HT2A receptor selective agonist 2,5-dimethoxy-4-methylamphetamine (0.1–3.2 mg/kg) induced head twitching, which was attenuated by the 5-HT2A receptor selective antagonist R-(+)-2,3-dimethoxyphenyl-1-[2-(4-piperidine)-methanol] (MDL 100907, 0.01 mg/kg), lorcaserin (3.2 mg/kg), and mCPP (3.2 mg/kg). In rats pretreated with MDL 100907 (1.0 mg/kg), lorcaserin also induced head twitching. At larger doses, lorcaserin produced forepaw treading, which was attenuated by the 5-HT1A receptor selective antagonist N-(2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl)-N-(2-pyridyl)cyclohexanecarboxamide (0.178 mg/kg). While the behavioral effects of lorcaserin in rats are consistent with it having agonist activity at 5-HT2C receptors, these data suggest that at larger doses it also has agonist activity at 5-HT2A and possibly 5-HT1A receptors. Mounting evidence suggests that 5-HT2C receptor agonists might be effective for treating drug abuse. A more complete description of the activity of lorcaserin at 5-HT receptor subtypes will facilitate a better understanding of the mechanisms that mediate its therapeutic effects. PMID:26384326

  12. Directly Observable Behavioral Effects of Lorcaserin in Rats.

    PubMed

    Serafine, Katherine M; Rice, Kenner C; France, Charles P

    2015-12-01

    (1R)-8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine (lorcaserin) is approved by the United States Food and Drug Administration for treating obesity, and its therapeutic effects are thought to result from agonist activity at serotonin (5-HT)2C receptors. Lorcaserin has affinity for other 5-HT receptor subtypes, although its activity at those subtypes is not fully described. The current study compared the behavioral effects of lorcaserin (0.0032-32.0 mg/kg) to the effects of other 5-HT receptor selective agonists in rats (n = 8). The 5-HT2C receptor selective agonist 1-(3-chlorophenyl)piperazine (mCPP, 0.032-1.0 mg/kg) and lorcaserin induced yawning which was attenuated by the 5-HT2C receptor selective antagonist 6-chloro-5-methyl-N-(6-[(2-methylpyridin-3-yl)oxy]pydidin-3-yl)indoline-1-carboxamide (1.0 mg/kg). The 5-HT2A receptor selective agonist 2,5-dimethoxy-4-methylamphetamine (0.1-3.2 mg/kg) induced head twitching, which was attenuated by the 5-HT2A receptor selective antagonist R-(+)-2,3-dimethoxyphenyl-1-[2-(4-piperidine)-methanol] (MDL 100907, 0.01 mg/kg), lorcaserin (3.2 mg/kg), and mCPP (3.2 mg/kg). In rats pretreated with MDL 100907 (1.0 mg/kg), lorcaserin also induced head twitching. At larger doses, lorcaserin produced forepaw treading, which was attenuated by the 5-HT1A receptor selective antagonist N-(2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl)-N-(2-pyridyl)cyclohexanecarboxamide (0.178 mg/kg). While the behavioral effects of lorcaserin in rats are consistent with it having agonist activity at 5-HT2C receptors, these data suggest that at larger doses it also has agonist activity at 5-HT2A and possibly 5-HT1A receptors. Mounting evidence suggests that 5-HT2C receptor agonists might be effective for treating drug abuse. A more complete description of the activity of lorcaserin at 5-HT receptor subtypes will facilitate a better understanding of the mechanisms that mediate its therapeutic effects. PMID:26384326

  13. 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.

  14. Direct visualization of memory effects in artificial spin ice

    NASA Astrophysics Data System (ADS)

    Gilbert, Ian; Chern, Gia-Wei; Fore, Bryce; Lao, Yuyang; Zhang, Sheng; Nisoli, Cristiano; Schiffer, Peter

    2015-09-01

    We experimentally demonstrate that arrays of interacting nanoscale ferromagnetic islands, known as artificial spin ice, develop reproducible microstates upon cycling an applied magnetic field. The onset of this memory effect is determined by the strength of the applied field relative to the array coercivity. Specifically, when the applied field strength is almost exactly equal to the array coercivity, several training cycles are required before the array achieves a nearly completely repeatable microstate, whereas when the applied field strength is stronger or weaker than the array coercivity, a repeatable microstate is achieved after the first minor loop. We show through experiment and simulation that this memory exhibited by artificial spin ice is due to a ratchet effect on interacting, magnetically charged defects in the island moment configuration and to the complexity of the network of strings of reversed moments that forms during magnetization reversal.

  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. Reliance on small samples, the wavy recency effect, and similarity-based learning.

    PubMed

    Plonsky, Ori; Teodorescu, Kinneret; Erev, Ido

    2015-10-01

    Many behavioral phenomena, including underweighting of rare events and probability matching, can be the product of a tendency to rely on small samples of experiences. Why would small samples be used, and which experiences are likely to be included in these samples? Previous studies suggest that a cognitively efficient reliance on the most recent experiences can be very effective. We explore a very different and more cognitively demanding process explaining the tendency to rely on small samples: exploitation of environmental regularities. The first part of our study shows that across wide classes of dynamic binary choice environments, focusing only on experiences that followed the same sequence of outcomes preceding the current task is more effective than focusing on the most recent experiences. The second part of our study examines the psychological significance of these sequence-based rules. It shows that these tractable rules reproduce well-known indications of sensitivity to sequences and predict a nontrivial wavy recency effect of rare events. Analysis of published data supports this wavy recency prediction, but suggests an even wavier effect than these sequence-based rules predict. This pattern, and the main behavioral phenomena documented in basic decisions from experience and probability learning tasks, can be captured with a similarity-based model assuming that people follow sequences of outcomes most of the time but sometimes respond to trends. We conclude with theoretical notes on similarity-based learning. PMID:26075914

  17. 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.

  18. A flexoelectricity effect-based sensor for direct torque measurement

    NASA Astrophysics Data System (ADS)

    Zhang, Shuwen; Xu, Minglong; Liu, Kaiyuan; Shen, Shengping

    2015-12-01

    In this study, a direct torque sensor based on the flexoelectricity generated by un-polarized polyvinylidene fluoride (PVDF) via electromechanical coupling is developed as a novel torque measurement mechanism that does not require external electric power excitation. The sensing method is developed based on the shear strain gradient and the shear flexoelectric response of PVDF. A theoretical analysis is primarily presented for the design of the sensing structure. Then the structure of the PVDF sensing module is discussed and designed. The radius ratio of the sensing module is defined and then discussed according to the load, the strain gradient, the electrode area and the general electric charge output. The finite element method is used to analyze the mechanical properties of the designed PVDF sensing module. Then the theoretical sensitivity of the sensor is predicated as 0.9441 pC Nm?1. The experiment system setup is developed, and the sensing properties of the measurement mechanism are tested at frequencies of 0.5 Hz, 1 Hz, 1.5 Hz and 2 Hz using identical modules. The measurement range of the designed sensor is 0–1.68 Nm and the average sensitivity is measured as 0.8950 pC Nm?1. The experimental results agree well with the theoretically predicted results. These results prove that the torque sensing method based on un-polarized PVDF is suitable for measurement of dynamic torque loads with a flexoelectricity-based mechanism. When using this method, external electric power excitation of the sensing module is no longer required.

  19. Direct radiative effect modeled for regional aerosols in central Europe including the effect of relative humidity

    NASA Astrophysics Data System (ADS)

    Iorga, G.; Hitzenberger, R.; Kasper-Giebl, A.; Puxbaum, Hans

    2007-01-01

    In view of both the climatic relevance of aerosols and the fact that aerosol burdens in central Europe are heavily impacted by anthropogenic sources, this study is focused on estimating the regional-scale direct radiative effect of aerosols in Austria. The aerosol data (over 80 samples in total) were collected during measurement campaigns at five sampling sites: the urban areas of Vienna, Linz, and Graz and on Mt. Rax (1644 m, regional background aerosol) and Mt. Sonnblick (3106 m, background aerosol). Aerosol mass size distributions were obtained with eight-stage (size range: 0.06-16 ?m diameter) and six-stage (size range 0.1-10 ?m) low-pressure cascade impactors. The size-segregated samples were analyzed for total carbon (TC), black carbon (BC), and inorganic ions. The aerosol at these five locations is compared in terms of size distributions, optical properties, and direct forcing. Mie calculations are performed for the dry aerosol at 60 wavelengths in the range 0.3-40 ?m. Using mass growth factors determined earlier, the optical properties are also estimated for higher relative humidities (60%, 70%, 80%, and 90%). A box model was used to estimate direct radiative forcing (DRF). The presence of absorbing species (BC) was found to reduce the cooling effect of the aerosols. The water-soluble substances dominate radiative forcing at the urban sites, while on Rax and Sonnblick BC plays the most important role. This result can be explained by the effect of the surface albedo, which is much lower in the urban regions (0.16) than at the ice and snow-covered mountain sites. Shortwave (below 4 ?m) and longwave surface albedo values for ice were 0.35 and 0.5, while for snow surface albedo, values of 0.8 (shortwave) and 0.5 (longwave) were used. In the case of dry aerosol, especially for urban sites, the unidentified material may contribute a large part to the forcing. Depending on the sampling site the estimated forcing gets more negative with increasing humidity. When humidity changes from 50% to 90%, the factor of forcing change for Graz is about 3 times larger than that for Linz (3.8) and about 5 times greater than that for Vienna (2.4). At the mountain stations the change in forcing with increasing humidity is much less pronounced because of the high surface albedo. The influence of the aerosol mixing state on the single-scattering albedo as well as on DRF is investigated for all sampling sites. As expected, the single-scattering albedo was found to have lower values for internal mixture than for external mixture.

  20. Treatment of high salinity brines by direct contact membrane distillation: Effect of membrane characteristics and salinity.

    PubMed

    Li, Jianfeng; Guan, Yunshan; Cheng, Fangqin; Liu, Yu

    2015-12-01

    Direct contact membrane distillation (DCMD) is one of the attractive technologies for high salinity brine treatment. In this study, four polytetrafluoroethylene (PTFE) membranes were examined in treating highly concentrated salt solutions. Results showed that non-supported membranes generally have a higher overall mass transfer coefficient but porosity seems to be the most important parameter controlling membrane flux and thermal efficiency. Supported membranes with large thickness had relatively higher thermal efficiency than small thickness. This can be attributed to their reduced heat loss through heat condition. In addition, KCl, NaCl and MgCl2 solutions showed distinct trends over flux decline at high salt concentrations (?2.0M). The difference in flux was largely due to the discrepancy in water activities of these solutions (KCl>NaCl>MgCl2). However, the effect of viscosity on permeate flux could not be neglected for MgCl2 at high salt concentrations as the suddenly increased viscosity could lead to serious temperature polarization. This study indicates that membrane distillation is a promising technology for high salinity brine treatment. PMID:25563165

  1. 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

  2. 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.

  3. 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

  4. Temperature Effects on the Wind Direction Measurement of 2D Solid Thermal Wind Sensors.

    PubMed

    Chen, Bei; Zhu, Yan-Qing; Yi, Zhenxiang; Qin, Ming; Huang, Qing-An

    2015-01-01

    For a two-dimensional solid silicon thermal wind sensor with symmetrical structure, the wind speed and direction information can be derived from the output voltages in two orthogonal directions, i.e., the north-south and east-west. However, the output voltages in these two directions will vary linearly with the ambient temperature. Therefore, in this paper, a temperature model to study the temperature effect on the wind direction measurement has been developed. A theoretical analysis has been presented first, and then Finite Element Method (FEM) simulations have been performed. It is found that due to symmetrical structure of the thermal wind sensor, the temperature effects on the output signals in the north-south and east-west directions are highly similar. As a result, the wind direction measurement of the thermal wind sensor is approximately independent of the ambient temperature. The experimental results fit the theoretical analysis and simulation results very well. PMID:26633398

  5. Heterogeneous Effects of Direct Hypoxia Pathway Activation in Kidney Cancer

    PubMed Central

    Salama, Rafik; Masson, Norma; Simpson, Peter; Sciesielski, Lina Katrin; Sun, Min; Tian, Ya-Min; Ratcliffe, Peter John; Mole, David Robert

    2015-01-01

    General activation of hypoxia-inducible factor (HIF) pathways is classically associated with adverse prognosis in cancer and has been proposed to contribute to oncogenic drive. In clear cell renal carcinoma (CCRC) HIF pathways are upregulated by inactivation of the von-Hippel-Lindau tumor suppressor. However HIF-1? and HIF-2? have contrasting effects on experimental tumor progression. To better understand this paradox we examined pan-genomic patterns of HIF DNA binding and associated gene expression in response to manipulation of HIF-1? and HIF-2? and related the findings to CCRC prognosis. Our findings reveal distinct pan-genomic organization of canonical and non-canonical HIF isoform-specific DNA binding at thousands of sites. Overall associations were observed between HIF-1?-specific binding, and genes associated with favorable prognosis and between HIF-2?-specific binding and adverse prognosis. However within each isoform-specific set, individual gene associations were heterogeneous in sign and magnitude, suggesting that activation of each HIF-? isoform contributes a highly complex mix of pro- and anti-tumorigenic effects. PMID:26262842

  6. Small head movements that accompany goal-directed arm movements provide various useful cues about the target's distance.

    PubMed

    de la Malla, Cristina; Buiteman, Stijn; Otters, Wilmer; Smeets, Jeroen; Brenner, Eli

    2015-09-01

    How a static object's position and orientation relative to oneself change when one moves one's head can be used to judge the object's distance. There are three distance cues that change when moving one's head: the direction of gaze that is required to fixate the object, the orientation of the object with respect to such a direction of gaze, and the object's position relative to distant objects in the retinal image. They do so to an extent that depends on the object's distance and on the magnitude of the head movement. When making goal-directed arm movements we inevitably move our head to some extent. To find out which, if any, of the above-mentioned cues influence distance judgments under such circumstances, we conducted a study in which participants had to move their index finger to virtual objects in the dark. The objects' sizes and positions varied across trials, with pairs of trials in which the same object was presented at the same location, except that one or more of the three above-mentioned cues was artificially manipulated to indicate that the object was either nearer or further away. We found that all three cues influence the movement endpoints, but the magnitude of the influence shows that the cues only contribute a few percent to the judged distance. Meeting abstract presented at VSS 2015. PMID:26326280

  7. Effective density and morphology of particles emitted from small-scale combustion of various wood fuels.

    PubMed

    Leskinen, Jani; Ihalainen, Mika; Torvela, Tiina; Kortelainen, Miika; Lamberg, Heikki; Tiitta, Petri; Jakobi, Gert; Grigonyte, Julija; Joutsensaari, Jorma; Sippula, Olli; Tissari, Jarkko; Virtanen, Annele; Zimmermann, Ralf; Jokiniemi, Jorma

    2014-11-18

    The effective density of fine particles emitted from small-scale wood combustion of various fuels were determined with a system consisting of an aerosol particle mass analyzer and a scanning mobility particle sizer (APM-SMPS). A novel sampling chamber was combined to the system to enable measurements of highly fluctuating combustion processes. In addition, mass-mobility exponents (relates mass and mobility size) were determined from the density data to describe the shape of the particles. Particle size, type of fuel, combustion phase, and combustion conditions were found to have an effect on the effective density and the particle shape. For example, steady combustion phase produced agglomerates with effective density of roughly 1 g cm(-3) for small particles, decreasing to 0.25 g cm(-3) for 400 nm particles. The effective density was higher for particles emitted from glowing embers phase (ca. 1-2 g cm(-3)), and a clear size dependency was not observed as the particles were nearly spherical in shape. This study shows that a single value cannot be used for the effective density of particles emitted from wood combustion. PMID:25365741

  8. Effects of Edge Directions on the Structural Controllability of Complex Networks

    PubMed Central

    Xiao, Yandong; Lao, Songyang; Hou, Lvlin; Small, Michael; Bai, Liang

    2015-01-01

    Recent advances indicate that assigning or reversing edge direction can significantly improve the structural controllability of complex networks. For directed networks, approaching the optimal structural controllability can be achieved by detecting and reversing certain “inappropriate” edge directions. However, the existence of multiple sets of “inappropriate” edge directions suggests that different edges have different effects on optimal controllability—that is, different combinations of edges can be reversed to achieve the same structural controllability. Therefore, we classify edges into three categories based on their direction: critical, redundant and intermittent. We then investigate the effects of changing these edge directions on network controllability, and demonstrate that the existence of more critical edge directions implies not only a lower cost of modifying inappropriate edges but also better controllability. Motivated by this finding, we present a simple edge orientation method aimed at producing more critical edge directions—utilizing only local information—which achieves near optimal controllability. Furthermore, we explore the effects of edge direction on the controllability of several real networks. PMID:26281042

  9. 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.

  10. Measurements of Siple transmitter signals on the DE 1 satellite - Wave normal direction and antenna effective length

    NASA Technical Reports Server (NTRS)

    Sonwalker, V. S.; Inan, U. S.

    1986-01-01

    A new experimental technique is developed to simultaneously measure the wave propagation direction and the effective length of a small (L value much smaller than wavelength) electric dipole antenna on a spin-stabilized satellite in the magnetosphere. The technique relies on the near simultaneous measurement of single components of the electric and magnetic fields of a coherent VLF signal injected into the medium from a ground-based source. The spin fading characteristics of the signal received by the electric dipole and the magnetic loop antenna permit the measurement of the wave normal direction assuming whistler-mode propagation. In-situ and remote measurements of the local cold plasma density are used to determine the refractive index. The wave electric field is then inferred from the wave magnetic field as measured on the loop antenna, the refractive index and the direction of propagation. Comparing this electric field with the measured voltage across the dipole antenna leads to the determination of the effective length of the receiving electric dipole. The technique is applied to data from the Dynamics Explorer 1 satellite observations of whistler mode signals injected into the magnetosphere from the Siple, Antarctica, VLF transmitter. In one case, with the measured background cold plasma density being 15 el/cu cm, the effective length of the 200 m-long electric dipole antenna is found to be 222 + or - 56 m, i.e., about twice the conventional value.

  11. 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

  12. The Effects of Transcranial Direct Current Stimulation (tDCS) on Fatigue During Maximal Intensity Exercise

    E-print Network

    Deckert, Jake Andrew

    2015-05-31

    The Effects of Transcranial Direct Current Stimulation (tDCS) on Fatigue During Maximal Intensity Exercise Jake A. Deckert1, Trent J. Herda1, Philip M. Gallagher1, & Joseph P. Weir1, FACSM, 1University of Kansas, Lawrence, Kansas Transcranial Direct...

  13. Home-Career Conflict Reduction Revisited: The Effect of Experimental Directions on KOIS Scores for Women

    ERIC Educational Resources Information Center

    Tittle, Carol Kehr; Denker, Elenor Rubin

    1976-01-01

    The effect of experimental directions designed to reduce a home-career conflict in women's occupational choices on the Kuder Occupational Interest Survey was investigated. Results indicate that the validity of the Kuder survey is not compromised by the experimental directions. Tables are presented and implications are discussed. (Author/JKS)

  14. 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

  15. 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...

  16. 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

  17. Temperature effect on the small-to-large crossover lengthscale of hydrophobic hydration

    SciTech Connect

    Djikaev, Y. S. Ruckenstein, E.

    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.

  18. 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

  19. Direct Production of 99mTc via 100Mo(p,2n) on Small Medical Cyclotrons

    NASA Astrophysics Data System (ADS)

    Schaffer, P.; Bénard, F.; Bernstein, A.; Buckley, K.; Celler, A.; Cockburn, N.; Corsaut, J.; Dodd, M.; Economou, C.; Eriksson, T.; Frontera, M.; Hanemaayer, V.; Hook, B.; Klug, J.; Kovacs, M.; Prato, F. S.; McDiarmid, S.; Ruth, T. J.; Shanks, C.; Valliant, J. F.; Zeisler, S.; Zetterberg, U.; Zavodszky, P. A.

    From the efforts of a number of Canadian institutions and private industry collaborations, direct production of 99mTc using medical cyclotrons has recently been advanced from a 1970's academic exercise to a commercial, economically viable solution for regional production. Using GE PETtrace 880 machines our team has established preliminary saturated yields of 2.7 GBq/?A, translating to approximately 174 GBq after a 6 hour irradiation. The team is in the process of assessing the accuracy and reliability of this production value with a goal of optimizing yields by up to 50%.

  20. Seagrass response to CO? contingent on epiphytic algae: indirect effects can overwhelm direct effects.

    PubMed

    Burnell, Owen W; Russell, Bayden D; Irving, Andrew D; Connell, Sean D

    2014-11-01

    Increased availability of dissolved CO2 in the ocean can enhance the productivity and growth of marine plants such as seagrasses and algae, but realised benefits may be contingent on additional conditions (e.g. light) that modify biotic interactions between these plant groups. The combined effects of future CO2 and differing light on the growth of seagrass and their algal epiphytes were tested by maintaining juvenile seagrasses Amphibolis antarctica under three different CO2 concentrations representing ambient, moderate future and high future forecasts (i.e. 390, 650 vs. 900 µl l(-1)) and two light levels representing low and high PAR (i.e. 43 vs. 167 µmol m(-2) s(-1)). Aboveground and belowground biomass, leaf growth, epiphyte cover, tissue chemistry and photosynthetic parameters of seagrasses were measured. At low light, there was a neutral to positive effect of elevated CO2 on seagrass biomass and growth; at high light, this effect of CO2 switched toward negative, as growth and biomass decreased at the highest CO2 level. These opposing responses to CO2 appeared to be closely linked to the overgrowth of seagrass by filamentous algal epiphytes when high light and CO2 were combined. Importantly, all seagrass plants maintained positive leaf growth throughout the experiment, indicating that growth was inhibited by some experimental conditions but not arrested entirely. Therefore, while greater light or elevated CO2 provided direct physiological benefits for seagrasses, such benefits were likely negated by overgrowth of epiphytic algae when greater light and CO2 were combined. This result demonstrates how indirect ecological effects from epiphytes can modify independent physiological predictions for seagrass associated with global change. PMID:25193313

  1. Interpolated task effects on direct and mediated false recognition: effects of initial recall, recognition, and the ironic effect of guessing.

    PubMed

    Huff, Mark J; Coane, Jennifer H; Hutchison, Keith A; Grasser, Elisabeth B; Blais, Jessica E

    2012-11-01

    In two experiments, participants studied two types of word lists. Direct lists were taken from the Deese-Roediger-McDermott (DRM) paradigm (e.g., water, bridge, run) and contained words directly related to a nonpresented critical item (CI; e.g., river, Roediger & McDermott, 1995). Mediated lists (e.g., faucet, London, jog) contained words related to the CI through a nonpresented mediator. After each study list, participants completed either a recall test, a recall test with a warning about the CI, arithmetic problems, or a recognition test, or they guessed the CI. On a final recognition test, both warning and guessing decreased direct false recognition but increased mediated false recognition, an ironic effect of guessing. An initial recognition test also increased final mediated false recognition. We argue that warning and guessing tasks strengthened associative pathways to the CI, increased the accessibility of associated mediators, and increased monitoring for the CI at test. Increased monitoring was able to reduce CIs from direct, but not mediated, lists. PMID:22642236

  2. 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...

  3. Food supplementation leads to increases in large mammal diversity and abundance, but no carry over effect in small mammals

    E-print Network

    Blouin-Demers, Gabriel

    Food supplementation leads to increases in large mammal diversity and abundance, but no carry over effect in small mammals Sana Zabihi-Seissan 5990458 BIO4009 ­ Honours Project Supervisors: Julie Morand sometimes impacts small mammal abundance and diversity. In this study, we looked at the carry-over effects

  4. Mediated and direct effects of the North Atlantic Ocean on winter temperatures in northwest Europe

    NASA Astrophysics Data System (ADS)

    Junge, Martina M.; Stephenson, David B.

    2003-03-01

    This study has used a multiple regression model to quantify the importance of wintertime mean North Atlantic sea-surface temperatures (SSTs) for explaining (simultaneous) variations in wintertime mean temperatures in northwestern Europe. Although wintertime temperature variations are primarily determined by atmospheric flow patterns, it has been speculated that North Atlantic SSTs might also provide some additional information. To test this hypothesis, we have attempted to explain 1900-93 variations in wintertime mean central England temperature (CET) by using multiple regression with contemporaneous winter mean North Atlantic sea-level pressures (SLPs) and SSTs as explanatory variables. With no SST information, the leading SLP patterns (including the North Atlantic oscillation) explain 63% of the total variance in winter mean CET; however, SSTs alone are capable of explaining only 16% of the variance in winter mean CET. Much of the SST effect is indirect in that it supplies no more significant information than already contained in the mean SLP; e.g. both SLP and SST together can only explain 68% of the variance. However, there is a small (5% variance) direct effect due to SST that is not mediated by mean SLP, which has a spatial pattern resembling the Newfoundland SST pattern identified by Ratcliffe and Murray (1970. Quarterly Journal of the Royal Meteorological Society 96: 226-246). In predictive mode, however, using explanatory variables from preceding seasons, SSTs contain more information than SLP factors. On longer time scales, the variance explained by contemporaneous SST increases, but the SLP explanatory variables still provide a better model than the SST variables.

  5. Offensive Sequences in Youth Soccer: Effects of Experience and Small-Sided Games

    PubMed Central

    Almeida, Carlos Humberto; Ferreira, António Paulo; Volossovitch, Anna

    2013-01-01

    The present study aimed to analyze the interaction and main effects of deliberate practice experience and small-sided game format (3 vs. 3 and 6 vs. 6 plus goalkeepers) on the offensive performance of young soccer players. Twenty-eight U-15 male players were divided into 2 groups according to their deliberate practice experience in soccer (i.e., years of experience in federation soccer): Non-Experienced (age: 12.84 ± 0.63 years) and Experienced (age: 12.91 ± 0.59 years; experience: 3.93 ± 1.00 years). The experimental protocol consisted of 3 independent sessions separated by one-week intervals. In each session both groups performed each small-sided game during 10 minutes interspersed with 5 minutes of passive recovery. To characterize the recorded offensive sequences we used the Offensive Sequences Characterization System, which includes performance indicators previous applied in other studies. No interaction effects on the offensive performance were found between both factors. Non-parametric MANOVA revealed that the factor “experience level” had a significant effect (p<0.05) on performance indicators that characterize the development of offensive sequences, especially in 6 vs. 6 + GKs. While experienced players produced longer offensive sequences with greater ball circulation between them, the non-experienced participants performed faster offensive sequences with a predominance of individual actions. Furthermore, significant differences were observed (p<0.05) in the development and finalization of offensive sequences within each group, when comparing small-sided game formats. Evidence supports that small-sided games can serve several purposes as specific means of training. However, the manipulation of game format should always consider the players’ individual constraints. PMID:23717359

  6. Setting the question for inquiry: The effects of whole class vs small group on student achievement in elementary science

    NASA Astrophysics Data System (ADS)

    Cavagnetto, Andy Roy

    This study was conducted to determine the effects of two different student-centered approaches to setting the question for inquiry. The first approach (whole class) consisted of students setting a single question for inquiry after which students worked in small groups during an investigation phase of the activity with all groups exploring the same question. The second approach (small group) consisted of each group of students setting a question resulting in numerous questions being explored per class. A mixed method quasi-experimental design was utilized. Two grade five teachers from a small rural school district in the Midwestern United States participated, each teaching two sections of science (approximately 25 students per section). Results indicate three major findings. Instructional approach (whole class vs. small group) did not effect student achievement in science or language arts. Observational data indicated the actions and skills teachers utilized to implement the approaches were similar. Specifically, the pedagogical skills of dialogical interaction (which was found to be influenced by teacher level of control of learning and teacher content knowledge) and effective rather than efficient use of time were identified as key factors in teachers' progression toward a student-centered, teacher-managed instructional approach. Unit exams along with qualitative and quantitative teacher observation data indicated that these factors do have an impact on student achievement. Specifically increased dialogical interaction in the forms of greater student voice, and increased cognitive demands placed on students by embedding and emphasizing science argument within the student inquiry corresponded to positive gains in student achievement. Additionally, teacher's perception of student abilities was also found to influence professional growth. Finally, allowing students to set the questions for inquiry and design the experiments impact the classroom environment as teacher talk changed from giving directions toward scaffolding student thought. These results have implications for professional development and teacher education as they suggest that more time should be spent on challenging teachers to align their pedagogy with how students learn rather than simply providing strategies and lesson plans for teachers to use in the classrooms.

  7. Aspirin-induced small bowel injuries and the preventive effect of rebamipide

    PubMed Central

    Mizukami, Kazuhiro; Murakami, Kazunari; Abe, Takashi; Inoue, Kunimitsu; Uchida, Masahiro; Okimoto, Tadayoshi; Kodama, Masaaki; Fujioka, Toshio

    2011-01-01

    AIM: To evaluate the influence of taking low-dose aspirin for 4 wk on small intestinal complications and to examine the preventive effect of rebamipide. METHODS: This study was conducted as a single-center, randomized, double-blind, cross-over, placebo-controlled study. Eleven healthy male subjects were enrolled. Each subject underwent video capsule endoscopy after 1 and 4 wk of taking aspirin and omeprazole, along with either rebamipide or placebo therapy. The primary endpoint was to evaluate small bowel damage in healthy subjects before and after taking low-dose aspirin for 4 wk. RESULTS: The number of subjects with mucosal breaks (defined as multiple erosions and/or ulcers) were 1 at 1 wk and 1 at 4 wk on the jejunum, and 6 at 1 wk (P = 0.0061) and 7 at 4 wk on the ileum (P = 0.0019). Rebamipide significantly prevented mucosal breaks on the ileum compared with the placebo group (P = 0.0173 at 1 wk and P = 0.0266 at 4 wk). CONCLUSION: Longer-term, low-dose aspirin administration induced damage in the small bowel. Rebamipide prevented this damage, and may be a candidate drug for treating aspirin-induced small bowel complications. PMID:22171147

  8. Observation of small-scale anisotropy in the arrival direction distribution of TeV cosmic rays with HAWC

    SciTech Connect

    Abeysekara, A. U.; Alfaro, R.; Belmont, E.; Alvarez, C.; Arceo, R.; Álvarez, J. D.; Arteaga-Velázquez, J. C.; Cotti, U.; Ayala Solares, H. A.; Barber, A. S.; Baughman, B. M.; Berley, D.; Braun, J.; Bautista-Elivar, N.; BenZvi, S. Y.; Bonilla Rosales, M.; Carramiñana, A.; Caballero-Mora, K. S.; Castillo, M.; Cotzomi, J.; Collaboration: HAWC Collaboration; and others

    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 × 10{sup 10} events recorded between 2013 June and 2014 February shows anisotropy at the 10{sup –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 ? = 15 contribute significantly to the excesses.

  9. Direct optical sensing of single unlabeled small proteins and super-resolution microscopy of their binding sites

    E-print Network

    Piliarik, Marek

    2013-01-01

    More than twenty years ago, scientists succeeded in pushing the limits of optical detection to single molecules using fluorescence. This breakthrough has revolutionized biophysical measurements, but restrictions in photophysics and labeling protocols have motivated many efforts to achieve fluorescence-free single-molecule sensitivity in biological studies. Although several interesting mechanisms using vibrational spectroscopy, photothermal detection, plasmonics or microcavities have been proposed for biosensing at the single-protein level, no method has succeeded in direct label-free detection of single proteins. Here, we present the first results using interferometric detection of scattering (iSCAT) from single proteins without the need for any label, optical nanostructure or microcavity. Furthermore, we demonstrate super-resolution imaging of protein binding with nanometer localization precision. The ease of iSCAT instrumentation promises a breakthrough for industrial usage as well as fundamental laboratory...

  10. Does a Low-wall Coverage Stent Have a Flow Diverting Effect in Small Aneurysms?

    PubMed Central

    Liu, Hairi; Choe, Jooae; Jung, Seung Chul; Song, Yunsun; Yang, Ku Hyun; Park, Kye Jin; Goo, Hae Won; Park, Won Hyong

    2015-01-01

    Backbround and Purpose The flow diverting effect of a low-wall coverage stent remains controversial. We evaluted patients who underwent stenting for small aneurysms with a low but potential risk of growth and reviewed related literature. Materials and Methods We evaluated 9 small aneurysms among 19 unruptured intracranial aneurysms from eight patients who underwent stenting. The patients had unexplainable severe headache (n = 8), aneurysm originating from the anterior choroidal artery (n = 3), potential growth or rupture risks including hypertension (n = 5), and multiple aneurysms (n = 6). Stents with a relatively low-wall coverage ratio (8-10%) were used. Clinical and angiographic outcomes were assessed. Results One (n = 8) or two stents (n = 1) were used without any procedural difficulties or complications. Although no immediate changes of aneurysm morphology were observed, aneurysms decreased in size (n = 8) when examined by DSA (n = 8) or MRA (n = 1) during a median 28.9-month follow-up. There were no adverse events, including thromboembolism, aneurysm rupture, or stent movement during a median 31.9-month clinical follow-up (range: 17-69 months). Conclusion Although a variable degree of aneurysm size decrease may not prevent further growth or rupture of small aneurysms, stenting with a low-wall coverage ratio may have some advantageous hemodynamic effect. Flow modification of stent architecture vs. aneurysm characteristics, including size and location, on long-term outcome, requires further clarification. PMID:26389012

  11. 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

  12. Effect of small-scale ionospheric variability on GNSS radio occultation data quality

    NASA Astrophysics Data System (ADS)

    Verkhoglyadova, O. P.; Mannucci, A. J.; Ao, C. O.; Iijima, B. A.; Kursinski, E. R.

    2015-09-01

    Global Navigation Satellite Systems (GNSS) radio occultation (RO) measurements are sensitive to thin ionization layers and small-scale ionosphere structures. To evaluate error bounds and possible biases in atmospheric retrievals, we characterized ionospheric irregularities encountered in the affected profiles by analyzing the L1 signal-to-noise ratio (SNR) variability at E layer altitudes (from 90 km to 130 km). New metrics to analyze statistical effects of small-scale ionospheric irregularities on refractivity retrievals are proposed. We analyzed refractivity (N) retrievals with Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) ROs in 2011. Using refractivity from European Centre for Medium-Range Weather Forecasts (ECMWF) analysis (NECMWF) as the reference data set, we studied statistical properties of the fractional refractivity bias (?N) defined by the difference (NECMWF - N)/NECMWF and averaged in the altitude range from 20 to 25 km for each individual profile. We found that (1) persistently larger variability of the L1 SNR as measured by the interquartile range (IQR) existed when the occultation tangent point was in the 90 km to 110 km altitude range than at higher E layer altitudes; (2) the upper limits on the fractional refractivity bias for COSMIC ROs are 0.06% (for daytime local time), 0.1% (for nighttime local time), and ~0.01% (for all local times); (3) distributions of ?N are non-Gaussian (leptokurtic); (4) latitudinal distributions of small and large ?N for different levels of ionospheric variability show large tails (NECMWF > N) occurring around the Himalaya and the Andes regions, which are possibly due to biases in ECMWF analysis. We conclude that the refractivity bias due to small-scale irregularities is small below 25 km altitude and can be neglected.

  13. Bias Formulas for Estimating Direct and Indirect Effects When Unmeasured Confounding Is Present.

    PubMed

    le Cessie, Saskia

    2016-01-01

    Mediation analysis examines the influence of intermediate factors in the causal pathway between an exposure and an outcome. It yields estimates of the direct effect of the exposure on the outcome and of the indirect effect through the intermediate variable. Both estimates can be biased if the relationship between the mediator and the outcome is confounded. In this article, we study the effect of unmeasured confounding on direct and indirect effect estimates for a continuous mediator and an outcome that may be either binary, count, or continuous. We formulate the effect of the confounder on the intermediate and on the outcome directly in regression models, which makes the formulas intuitive to use by applied users. The formulas are derived under the assumption that the confounder follows a normal distribution. In simulations, the formulas for a linear response model performed well, also as it did when the unmeasured confounder was binary. For a rare binary outcome, the formulas for logistic regression performed well if the unmeasured confounder followed a normal distribution, but for a binary confounder the bias in the direct effect was overcorrected. We applied the formulas to data from a case-control study (Leiden Thrombophilia Study) on risk factors for venous thrombosis. This showed that unmeasured confounding can severely bias the estimates of direct and indirect effects. PMID:26426943

  14. Radiotelemetric analysis of the effects of prevailing wind direction on Mormon cricket migratory band movement.

    PubMed

    Sword, G A; Lorch, P D; Gwynne, D T

    2008-08-01

    During outbreaks, flightless Mormon crickets [Anabrus simplex Haldeman (Orthoptera: Tettigoniidae)] form large mobile groups known as migratory bands. These bands can contain millions of individuals that march en masse across the landscape. The role of environmental cues in influencing the movement direction of migratory bands is poorly understood and has been the subject of little empirical study. We examined the effect of wind direction on Mormon cricket migratory band movement direction by monitoring the local weather conditions and daily movement patterns of individual insects traveling in bands over the same time course at three close, but spatially distinct sites. Although weather conditions were relatively homogeneous across sites, wind directions tended to be more variable across sites during the morning hours, the period during which directional movement begins. Migratory bands at different sites traveled in distinctly different directions. However, we failed to find any evidence to suggest that the observed variation in migratory band movement direction was correlated with local wind direction at any time during the day. These results support the notion that the cues mediating migratory band directionality are likely to be group specific and that a role for landscape-scale environmental cues such as wind direction is unlikely. PMID:18801254

  15. 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

  16. The effects of small amounts of H2O on partial melting of model spinel lherzolite in the system CMAS

    NASA Astrophysics Data System (ADS)

    Liu, X.; St. C. Oneill, H.

    2003-04-01

    Water (H_2O) is so effective at lowering the solidus temperatures of silicate systems that even small amounts of H_2O are suspected to be important in the genesis of basaltic magmas. The realization that petrologically significant amounts of H_2O can be stored in nominally anhydrous mantle minerals (olivine and pyroxenes) has fundamental implications for the understanding of partial melting in the mantle, for it implies that the role that H_2O plays in mantle melting may not be appropriately described by models in which the melting is controlled by hydrous phases such as amphibole. Although the effect of water in suppressing the liquidus during crystallization is quite well understood, such observations do not provide direct quantitative information on the solidus. This is because liquidus crystallization occurs at constant major-element composition of the system, but at unbuffered component activities (high thermodynamic variance). By contrast, for partial melting at the solidus the major-element component activities are buffered by the coexisting crystalline phases (low variance), but the major-element composition of the melt can change as a function of added H_2O. Accordingly we have determined both the solidus temperature and the melt composition in the system CMAS with small additions of H_2O, to 4 wt%, in equilibrium with the four-phase lherzolite assemblage of fo+opx+cpx+sp. Experiments were conducted at 1.1 GPa and temperatures from 1473 K to the dry solidus at 1593 K in a piston-cylinder apparatus. Starting materials were pre-synthesised assemblage of fo+opx+cpx+sp, plus an oxide/hydroxide mix of approximately the anticipated melt composition. H_2O was added as either Mg(OH)_2 or Al(OH)_3. The crystalline assemblage and melt starting mix were added as separate layers inside sealed Pt capsules, to ensure large volumes of crystal-free melt. After the run doubly polished sections were prepared in order to analyse the quenched melt by FTIR spectroscopy, to quantify the amounts of H_2O. This is necessary, as Pt capsules are to some extent open to H_2 diffusion. All melts were found to contain CO_2 (<0.7 wt%), which appears to come mainly from the hydroxide starting materials but also by C diffusion through the Pt capsule. Since CO_2 is experimentally correlated with H_2O, its presence significantly effects the interpretation of the results. Ignoring this complication, we find that 1 wt% H_2O decreases the solidus by ˜40 K; melt compositions do not change greatly, the main effect being a small decrease in MgO.

  17. 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.

  18. 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.

  19. Radiation dose effect in locally advanced non-small cell lung cancer

    PubMed Central

    Zhao, Jing; Wang, Jingbo; Faivre-Finn, Corrine

    2014-01-01

    Radiation is the foundation of treatment for locally advanced non-small cell lung cancer (NSCLC), and as such, optimal radiation dose is essential for successful treatment. This article will briefly review biological considerations of radiation dose and their effect in the context of three-dimensional conformal radiation therapy (3D-CRT) including intensity modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) for NSCLC. It will focus on literature review and discussions regarding radiation dose effect in locally advanced NSCLC including potential severe and lethal toxicities of high dose radiation given with concurrent chemotherapy. Potential new approaches for delivering safe and effective doses by individualizing treatment based on functional imaging are being applied in studies such as the PET boost trial and RTOG1106. The RTOG concept of delivering high dose radiation to the more resistant tumors with the use of isotoxic dose prescription and adaptive planning will also be discussed in detail. PMID:24688778

  20. Effects of pharmaceutical excipients on membrane permeability in rat small intestine.

    PubMed

    Takizawa, Yusuke; Kishimoto, Hisanao; Nakagawa, Minami; Sakamoto, Nasa; Tobe, Yoshifusa; Furuya, Takahito; Tomita, Mikio; Hayashi, Masahiro

    2013-09-10

    Pharmaceutical excipients should not disturb the effects of drug therapy. In recent years, however, it has been reported that excipients induce some changes to the tight junction (TJ) and P-glycoprotein (P-gp), which can affect drug disposition. In this study, we examined the effects of 20 common pharmaceutical excipients from different classes on mucosal membrane and the differences of such effects among regions of the small intestine. We used the in vitro sac method in rat jejunum and ileum to study the effects of excipients on the membrane permeation of 5(6)-carboxyfluorescein (5-CF). 5-CF was used as a model of water-soluble compounds. In some dosage conditions of methyl-?-cyclodextrin, the membrane permeability of 5-CF was significantly increased in the jejunum, but such change was not observed in the ileum. Similarly, in the cases of sodium carboxymethyl starch, low-substituted hydroxypropyl cellulose and croscarmellose sodium, the membrane permeability of 5-CF was significantly increased in the jejunum, but no change was observed in the ileum. On the other hand, in both the jejunum and the ileum, the membrane permeation of 5-CF was decreased with 0.02% (w/v) hydroxypropyl cellulose, but significantly increased with it at 0.20% (w/v). It was shown that excipients affected the membrane permeability of water-soluble compounds via the paracellular route, and these effects on absorption differed among regions of the small intestine. Moreover, in the case of 20 excipients, not only an increase in membrane permeability but also a decrease was observed. Therefore, it was suggested that a more effective formulation could be designed by changing the combination of excipients. PMID:23742974

  1. 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

  2. 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

  3. 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

  4. 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…

  5. 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 ...

  6. Influence of Exercise on Inflammation in Cancer: Direct Effect or Innocent Bystander?

    PubMed

    Murphy, E Angela; Enos, Reilly T; Velázquez, Kandy T

    2015-07-01

    We propose the hypothesis that the benefits of exercise on inflammation in cancer are a result of a direct effect on inflammatory cytokines, including interleukin-6, tumor necrosis factor-?, and monocyte chemoattractant protein 1, that are critical for cancer growth as well as a bystander effect of the established relationship between exercise and cancer. PMID:25906430

  7. 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…

  8. Interpersonal Attraction and Direct-Indirect Supervisor Influence as Predictors of Counselor Trainee Effectiveness.

    ERIC Educational Resources Information Center

    Dodenhoff, Judith T.

    1981-01-01

    Trainees who were attracted to their supervisors were rated as more effective by supervisors, although attraction was not related to clients' perceptions of outcome. A direct style of supervision was related to trainee effectiveness, but on only one of three measures of the dependent variable. (Author)

  9. Effects of directional expectations on motion perception and pursuit eye movements

    E-print Network

    Adler, Scott A.

    Effects of directional expectations on motion perception and pursuit eye movements RICHARD J judgements and pursuit eye movements. However, it is not known whether these two effects are due to shared display and measuring both the perceptual judgements and pursuit eye movements elicited by the stimulus

  10. A Direct Measurement Scheme of Amalgamated Aging Effects with Novel On-Chip Sensor

    E-print Network

    Cotofana, Sorin

    to detect the amalgamated aging effects of ICs caused by joint failure mechanisms. This is achievedA Direct Measurement Scheme of Amalgamated Aging Effects with Novel On-Chip Sensor Nicoleta Cucu ICs' lifetime reliability. Though, up to date, various aging sensors have been proposed, few of them

  11. The Effect of Direct Instruction Model on Intermediate Class Achievement and Attitudes toward English Grammar

    ERIC Educational Resources Information Center

    Kousar, Rubina

    2010-01-01

    This study was aimed at investigating the effect of the direct instruction model on intermediate class achievement and attitudes toward English grammar. It was an experimental study and the purpose was to explore the relative effectiveness of instructional methodology (independent variable) on students' achievement and attitude (dependent…

  12. Direct and Indirect Effects of Teenage Body Weight on Adult Wages. NBER Working Paper No. 15027

    ERIC Educational Resources Information Center

    Han, Euna; Norton, Edward C.; Powell, Lisa M.

    2009-01-01

    Previous estimates on the association between body weight and wages in the literature have been contingent on education and occupation. This paper examines the direct effect of BMI on wages and the indirect effects operating through education and occupation choice, particularly for late-teen BMI and adult wages. Using the National Longitudinal…

  13. Effects of Diurnal Modulation in Direct Cold Dark Matter Searches. the Experiment in Sierra Grande

    E-print Network

    Gregorio, D E D; Huck, H; Macchiavelli, A O; Gil, S; Collar, J I

    1993-01-01

    Contains a summary, current status and prospects for the direct detection of cold dark matter using diurnal modulation effects as presented at the ELAF 93, Mar del Plata Argentina. The potential advantages of using the Earth as an absorber to produce diurnal modulation effects in cold dark matter searches are given along with some estimates of counting rates.

  14. 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.

  15. Protective Effect of Sodium Nitroprusside on the Rat Small Intestine Transplanted Mucosa

    PubMed Central

    Yin, Lu; Yan, Zhao-Wen

    2015-01-01

    The intestinal mucosal epithelium is extremely susceptible to even brief periods of ischemia. Mucosal barrier damage, which is associated with ischemia/reperfusion (I/R) injury and consequently bacterial translocation, remains a major obstacle for clinically successful small bowel transplantation (SBT). Previous studies have demonstrated a protective effect of nitric oxide (NO) on other transplanted organs and NO mediated intestinal protection has also been reported in vitro. The aim of this study was to evaluate the effect of sodium nitroprusside (SNP), NO donor, on graft mucosal histology and molecular markers of function after SBT in rats. We used SNP in different period of heterotopic SBT rats. The groups consisted of SBT, pre-SNP group, and post-SNP group. Interestingly, the pre-SNP graft samples exhibited less damage compared to the SBT and post-SNP samples. In addition, mucosal samples from the pre-SNP group showed higher Na+-K+-ATPase activity and higher levels of laminin expression compared to the SBT and post-SNP samples. The findings of the present study reveal that SNP given before graft ischemia/reperfusion injury has a protective effect on mucosal histology and molecular markers of function in the transplanted small intestine. PMID:25650248

  16. Dynamical Casimir effect in a small compact manifold for the Maxwell vacuum

    NASA Astrophysics Data System (ADS)

    Zhitnitsky, Ariel R.

    2015-05-01

    We study a novel type of contribution to the partition function of the Maxwell system defined on a small compact manifold M such as a torus. These new terms cannot be described in terms of the physical propagating photons with two transverse polarizations. Rather, these novel contributions emerge as a result of tunneling 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, then 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 tunneling events between topologically different but physically identical |k ? sectors in a time-dependent background. We comment on the relation of this novel effect to 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.

  17. A microphysical interpretation of the rate-and-state friction direct effect: implications for the seismic cycle

    NASA Astrophysics Data System (ADS)

    van den Ende, Martijn; Niemeijer, André; Spiers, Christopher

    2015-04-01

    For many years, empirical rate-and-state friction laws have been successfully applied to describe the transient frictional behaviour of fault zones, as observed in laboratory experiments and in nature. However, the rate-and-state friction parameters and equations are still poorly understood in terms of the underlying processes that operate at a micro-scale. In addition, there exist large discrepancies between lab-derived values and estimated values for natural fault zones. Because of these discrepancies, extrapolation of the frictional behaviour from sample-scale to the spatial and temporal scales of natural faults is non-trivial. Most notably, there is only a small theoretical basis for the near-instantaneous increase in friction after a sudden increase in sliding velocity (known as the direct effect). Marone et al. (1990) observed a positive relationship between the direct effect and dilatation in quartz gouges. However, the magnitude of the dilatation was significantly higher than expected based on the change in friction, which they explained by non-coaxial dilatation. In more recent years, Beeler et al. (2007) used a normalisation scheme to show that in the case of phyllosilicates, the magnitude of the direct effect is comparable to the stress required for dislocation glide. However, dislocation glide does not explain a-values for "hard" minerals such as quartz and calcite, especially when fluid-rock interactions are rapid. To address these issues, room temperature velocity stepping experiments have been conducted on granular calcite, and granular rock salt as an analogue for quartz under hydrothermal conditions. These experiments clearly demonstrate that the magnitude of the direct effect is much larger in gouges where pressure solution rates are high and deformation is distributed. A large contribution of dilatation to the magnitude of the direct effect becomes apparent in these gouges. In contrast, calcite gouges in which pressure solution is slow, show a small direct effect, which can not be accounted for by dilatation alone. Localisation of deformation decreases the magnitude of the direct effect, which is in agreement with observations by Marone et al. (1990). We are in the process of developing a microphysical model to explain the observed behaviour and to allow for extrapolation to natural conditions. Our microphysically based and experimentally verified model will help gain a better understanding of the seismic cycle. References: Beeler N. M., T. E. Tullis, A. K. Kronenberg, and L. A. Reinen (2007), Instantaneous rate dependence in low temperature laboratory rock friction and rock deformation experiments, J. Geophys. Res., 112, B07310, doi:10.1029/2005JB003772 Marone C., C. B. Raleigh, and C. H. Scholz (1990), Frictional behavior and constitutive modeling of simulated fault gouge, J. Geophys. Res., 95 (B5), 7007-7025, doi:10.1029/JB095iB05p07007

  18. Direct and indirect effects of biological factors on extinction risk in fossil bivalves

    PubMed Central

    Harnik, Paul G.

    2011-01-01

    Biological factors, such as abundance and body size, may contribute directly to extinction risk and indirectly through their influence on other biological characteristics, such as geographic range size. Paleontological data can be used to explicitly test many of these hypothesized relationships, and general patterns revealed through analysis of the fossil record can help refine predictive models of extinction risk developed for extant species. Here, I use structural equation modeling to tease apart the contributions of three canonical predictors of extinction—abundance, body size, and geographic range size—to the duration of bivalve species in the early Cenozoic marine fossil record of the eastern United States. I find that geographic range size has a strong direct effect on extinction risk and that an apparent direct effect of abundance can be explained entirely by its covariation with geographic range. The influence of geographic range on extinction risk is manifest across three ecologically disparate bivalve clades. Body size also has strong direct effects on extinction risk but operates in opposing directions in different clades, and thus, it seems to be decoupled from extinction risk in bivalves as a whole. Although abundance does not directly predict extinction risk, I reveal weak indirect effects of both abundance and body size through their positive influence on geographic range size. Multivariate models that account for the pervasive covariation between biological factors and extinction are necessary for assessing causality in evolutionary processes and making informed predictions in applied conservation efforts. PMID:21808004

  19. Effect of Thermal Degradation on High Temperature Ultrasonic Transducer Performance in Small Modular Reactors

    NASA Astrophysics Data System (ADS)

    Bilgunde, Prathamesh N.; Bond, Leonard J.

    Prototype ultrasonic NDT transducers for use in immersion in coolants for small modular reactors have shown low signal to noise ratio. The reasons for the limitations in performance at high temperature are under investigation, and include changes in component properties. This current work seeks to quantify the issue of thermal expansion and degradation of the piezoelectric material in a transducer using a finite element method. The computational model represents an experimental set up for an ultrasonic transducer in a pulse-echo mode immersed in a liquid sodium coolant. Effect on transmitted and received ultrasonic signal due to elevated temperature (?200oC) has been analysed.

  20. High-multiplicity pA collisions and the small-x effective action

    E-print Network

    A. Dumitru

    2002-10-29

    I discuss the p_t distributions for high-multiplicity events originating from semi-classical variation of the gluon density of the proton.The multiplicity distribution measures the curvature of the effective action for the small-x gluon fields. For pA collisions at the RHIC and LHC colliders, semi-classically the multiplicity distribution reflects the distribution of saturation momenta of the proton but not that of the nucleus. The average transverse momentum in the central region grows with dN/dy, while the p_t distribution of leading hadrons in the proton fragmentation region should depend less on the multiplicity in the central region.

  1. 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.

  2. The effects of small ice crystals on the infrared radiative properties of cirrus clouds

    NASA Technical Reports Server (NTRS)

    Takano, Y.; Liou, K. N.; Asano, S.; Heymsfield, A.; Minnis, P.

    1990-01-01

    To be successful in the development of satellite retrieval methodologies for the determination of cirrus cloud properties, we must have fundamental scattering and absorption data on nonspherical ice crystals that are found in cirrus clouds. Recent aircraft observations (Platt et al. 1989) reveal that there is a large amount of small ice particles, on the order of 10 micron, in cirrus clouds. Thus it is important to explore the potential differences in the scattering and absorption properties of ice crystals with respect to their sizes and shapes. In this study the effects of nonspherical small ice crystals on the infrared radiative properties of cirrus clouds are investigated using light scattering properties of spheroidal particles. In Section 2, using the anomalous diffraction theory for spheres and results from the exact spheroid scattering program, efficient parameterization equations are developed for calculations of the scattering and absorption properties for small ice crystals. Parameterization formulas are also developed for large ice crystals using results computed from the geometric ray-tracing technique and the Fraunhofer diffraction theory for spheroids and hexagonal crystals. This is presented in Section 3. Finally, applications to the satellite remote sensing are described in Section 4.

  3. Statistically small effects of the Implicit Association Test can have societally large effects.

    PubMed

    Greenwald, Anthony G; Banaji, Mahzarin R; Nosek, Brian A

    2015-04-01

    Greenwald, Poehlman, Uhlmann, and Banaji (2009; GPUB hereafter) reported an average predictive validity correlation of r? = .236 for Implicit Association Test (IAT) measures involving Black-White racial attitudes and stereotypes. Oswald, Mitchell, Blanton, Jaccard, and Tetlock (2013; OMBJT) reported a lower aggregate figure for correlations involving IAT measures (r? = .148). The difference between the estimates of the 2 reviews was due mostly to their use of different policies for including effect sizes. GPUB limited their study to findings that assessed theoretically expected attitude-behavior and stereotype-judgment correlations along with others that the authors expected to show positive correlations. OMBJT included a substantial minority of correlations for which there was no theoretical expectation of a predictive relationship. Regardless of inclusion policy, both meta-analyses estimated aggregate correlational effect sizes that were large enough to explain discriminatory impacts that are societally significant either because they can affect many people simultaneously or because they can repeatedly affect single persons. PMID:25402677

  4. The optical effects of small iron particles that darken but do not redden: Evidence of intense space weathering on Mercury

    NASA Astrophysics Data System (ADS)

    Lucey, Paul G.; Riner, Miriam A.

    2011-04-01

    Submicroscopic iron particles larger than about 50 nm, infused throughout mineral grains or glasses, are abundant in planetary materials altered by their environment such as shocked meteorites and lunar agglutinate glasses. Such particles darken their host material but do not redden their spectra but to date there has been no theoretical treatment of their optical effects. Using Mie theory, we modify the Hapke (2001) radiative transfer model of the effects of space weathering to include these effects. Comparison with laboratory measurements shows that the new treatment reproduces the relationship between submicroscopic iron size, abundance and reflectance. We apply this new model to near-IR spectra of Mercury recently obtained by the MESSENGER spacecraft and find that submicroscopic iron is much more abundant on Mercury than in lunar soils, with typical total submicroscopic iron abundances near 3.5 wt.% compared to about 0.5 wt.% for lunar soils We also find that the ratio of iron particles that darken but do not redden to the abundance of very small iron particles that impart the red slope to space weathered material is much larger than lunar (6 vs. 2). Both the total submicroscopic iron abundance and ratio of particle size fractions are consistent with the higher production of melt and vapor in micrometeorite impact on Mercury relative to the Moon ( Cintala, 1992) that enables more accumulation of space weathering products before sequestration by regolith overturn. The radiative transfer model cannot directly constrain the abundance of opaque minerals on Mercury because of ambiguities between the darkening effects of opaques and submicroscopic iron particles larger than 50 nm, but assuming the opaques are the ultimate source of the submicroscopic iron, our results place a lower limit of 4-20 wt.% on opaque abundance on Mercury depending on the composition of the opaque phase and whether titanium metal also contributes to the space weathering effect.

  5. Separation and Measurement of Direct and Indirect Effects of Light on Stomata 1

    PubMed Central

    Sharkey, Thomas D.; Raschke, Klaus

    1981-01-01

    Conductance for water vapor, assimilation of CO2, and intercellular CO2 concentration of leaves of five species were determined at various irradiances and ambient CO2 concentrations. Conductance and assimilation were then plotted as functions of irradiance and intercellular CO2 concentration. The slopes of these curves allowed us to estimate infinitesimal changes in conductance (and assimilation) that occurred when irradiance changed and intercellular CO2 concentration was constant, and when CO2 concentration changed and irradiance was constant. On leaves of Xanthium strumarium L., Gossypium hirsutum L., Phaseolus vulgaris L., and Perilla frutescens (L.), Britt., the stomatal response to light was determined to be mainly a direct response to light and to a small extent only a response to changes in intercellular CO2 concentration. This was also true for stomata of Zea mays L., except at irradiances < 150 watts per square meter, when stomata responded primarily to the depletion of the intercellular spaces of CO2 which in turn was caused by changes in the assimilation of CO2. Stomata responded to light even in leaves whose net exchange of CO2 was reduced to zero through application of the inhibitor of photosynthetic electron transport, cyanazine (2-chloro-4[1-cyano-1-methylethylamino]-6-ethylamino-S-triazine). 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 (presumably in the guard cells). In leaves of X. strumarium, the direct effect of light on conductance is primarily a response to blue light. Stomatal responses to CO2 and to light opposed each other. In X. strumarium, stomatal opening in response to light was strongest in CO2 free air and saturated at lower irradiances than in CO2 containing air. Conversely, stomatal closure in response to CO2 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 CO2 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, but when the data were normalized with respect to the conductance at the highest irradiance, the various curves were congruent. PMID:16661884

  6. Dual-Route Model of the Effect of Head Orientation on Perceived Gaze Direction

    PubMed Central

    2014-01-01

    Previous studies on gaze perception have identified 2 opposing effects of head orientation on perceived gaze direction—1 repulsive and the other attractive. However, the relationship between these 2 effects has remained unclear. By using a gaze categorization task, the current study examined the effect of head orientation on the perceived direction of gaze in a whole-head condition and an eye-region condition. We found that the perceived direction of gaze was generally biased in the opposite direction to head orientation (a repulsive effect). Importantly, the magnitude of the repulsive effect was more pronounced in the eye-region condition than in the whole-head condition. Based on these findings, we developed a dual-route model, which proposes that the 2 opposing effects of head orientation occur through 2 distinct routes. In the framework of this dual-route model, we explain and reconcile the findings from previous studies, and provide a functional account of attractive and repulsive effects and their interaction. PMID:24730742

  7. Effective Small RNA Destruction by the Expression of a Short Tandem Target Mimic in Arabidopsis[C][W

    PubMed Central

    Yan, Jun; Gu, Yiyou; Jia, Xiaoyun; Kang, Wenjun; Pan, Shangjin; Tang, Xiaoqing; Chen, Xuemei; Tang, Guiliang

    2012-01-01

    MicroRNAs (miRNAs) and other endogenous small RNAs act as sequence-specific regulators of the genome, transcriptome, and proteome in eukaryotes. The interrogation of small RNA functions requires an effective, widely applicable method to specifically block small RNA function. Here, we report the development of a highly effective technology that targets specific endogenous miRNAs or small interfering RNAs for destruction in Arabidopsis thaliana. We show that the expression of a short tandem target mimic (STTM), which is composed of two short sequences mimicking small RNA target sites, separated by a linker of an empirically determined optimal size, leads to the degradation of targeted small RNAs by small RNA degrading nucleases. The efficacy of the technology was demonstrated by the strong and specific developmental defects triggered by STTMs targeting three miRNAs and an endogenous siRNA. In summary, we developed an effective approach for the destruction of endogenous small RNAs, thereby providing a powerful tool for functional genomics of small RNA molecules in plants and potentially animals. PMID:22345490

  8. Effect of an inlet temperature disturbance on the propagation of methane-air premixed flames in small tubes

    SciTech Connect

    Kim, Nam Il

    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)

  9. Exempting Mental Health Peer Support Services From Copayments. Direct final rule; confirmation of effective date.

    PubMed

    2015-11-01

    The Department of Veterans Affairs (VA) published a direct final rule amending its regulation that governs VA services that are not subject to copayment requirements for inpatient hospital care or outpatient medical care. Specifically, the regulation is amended to exempt mental health peer support services from having any required copayment. VA received no adverse comments concerning the direct final rule or its companion substantially identical proposed rule published in the Federal Register on the same date. This document confirms that the direct final rule became effective on January 27, 2015. In a companion document in this issue of the Federal Register, we are withdrawing as unnecessary the proposed rule. PMID:26552110

  10. Retrieval intention modulates the effects of directed forgetting instructions on recollection.

    PubMed

    Xiao, Xin; Lucas, Heather D; Paller, Ken A; Ding, Jin-Hong; Guo, Chun-Yan

    2014-01-01

    The neurocognitive basis of memory retrieval is often examined by investigating brain potential old/new effects, which are differences in brain activity between successfully remembered repeated stimuli and correctly rejected new stimuli in a recognition test. In this study, we combined analyses of old/new effects for words with an item-method directed-forgetting manipulation in order to isolate differences between the retrieval processes elicited by words that participants were initially instructed to commit to memory and those that participants were initially instructed to forget. We compared old/new effects elicited by to-be-forgotten (TBF) words with those elicited by to-be-remembered (TBR) words in both an explicit-memory test (a recognition test) and an implicit-memory test (a lexical-decision test). Behavioral results showed clear directed forgetting effects in the recognition test, but not in the lexical decision test. Mirroring the behavioral findings, analyses of brain potentials showed evidence of directed forgetting only in the recognition test. In this test, potentials from 450-650 ms (P600 old/new effects) were more positive for TBR relative to TBF words. By contrast, P600 effects evident during the lexical-decision test did not differ in magnitude between TBR and TBF items. When taken in the context of prior studies that have linked similar parietal old/new effects to the recollection of episodic information, these data suggest that directed-forgetting effects manifest primarily in greater episodic retrieval by TBR than TBF items, and that retrieval intention may be important for these directed-forgetting effects to occur. PMID:25140658

  11. Salicylate isomer-specific effect on the micellization of dodecyltrimethylammonium chloride: large effects from small changes.

    PubMed

    Šarac, Bojan; Mériguet, Guillaume; Ancian, Bernard; Bešter-Roga?, Marija

    2013-04-01

    Specific effects of the sodium salts of m- and p-hydroxybenzoates (m-HB and p-HB) on the aggregation process of dodecyltrimethylammonium chloride have been investigated by isothermal titration calorimetry, electrical conductivity, and (1)H NMR and compared with already reported data for the sodium salt of o-hydroxybenzoate (o-HB). For p-HB, it has been found that the aggregate is only formed by spherical micelles at all p-HB concentrations. On the other side, the situation is more complex for o-HB, where two distinct states of aggregation can be involved, depending on the concentration of o-HB. At high salt concentration, rodlike micelles are formed, whereas at lower concentration spherical aggregates are predominant. The transition from the cylinder to the sphere increases the mobility of the surfactant because the core of the rodlike micelles is more closely packed due to the expulsion of water from the interior of the aggregate. m-HB exhibits an intermediate behavior between these two extreme situations. The effect of the position of hydrophilic substituents on the aromatic ring on the insertion of the hydroxybenzoate anion in the micellar aggregate has been discussed. PMID:23477611

  12. Abundance of small individuals influences the effectiveness of processing techniques for deep-sea nematodes

    NASA Astrophysics Data System (ADS)

    Leduc, D.; Probert, P. K.; Berkenbusch, K.; Nodder, S. D.; Pilditch, C. A.

    2010-10-01

    Nematodes are the most abundant metazoans of deep-sea benthic communities, but knowledge of their distribution is limited relative to larger organisms. Whilst some aspects of nematode processing techniques, such as extraction, have been extensively studied, other key elements have attracted little attention. We compared the effect of (1) mesh size (63, 45, and 32 ?m) on estimates of nematode abundance, biomass, and body size, and (2) microscope magnification (50× and 100×) on estimates of nematode abundance at bathyal sites (250-3100 m water depth) on the Challenger Plateau and Chatham Rise, south-west Pacific Ocean. Variation in the effectiveness of these techniques was assessed in relation to nematode body size and environmental parameters (water depth, sediment organic matter content, %silt/clay, and chloroplastic pigments). The 63-?m mesh retained a relatively low proportion of total nematode abundance (mean±SD=55±9%), but most of nematode biomass (90±4%). The proportion of nematode abundance retained on the 45-?m mesh in surface (0-1 cm) and subsurface (1-5 cm) sediment was significantly correlated ( P<0.01) with %silt/clay ( R2=0.39) and chloroplastic pigments ( R2=0.29), respectively. Variation in median nematode body weight showed similar trends, but relationships between mean nematode body weight and environmental parameters were either relatively weak (subsurface sediment) or not significant (surface sediment). Using a low magnification led to significantly lower (on average by 43%) nematode abundance estimates relative to high magnification ( P<0.001), and the magnitude of this difference was significantly correlated ( P<0.05) with total nematode abundance ( R2p=0.53) and the number of small (?250 ?m length) individuals ( R2p=0.05). Our results suggest that organic matter input and sediment characteristics influence the abundance of small nematodes in bathyal communities. The abundance of small individuals can, in turn, influence abundance estimates obtained using different mesh sizes and microscope magnifications.

  13. Hadrons and direct photon in pp and pA collisions at LHC and saturation effects

    E-print Network

    Amir H. Rezaeian; Andreas Schaefer

    2010-06-04

    We investigate hadrons and direct photon production in pp and pA collisions at the energies of RHIC and LHC within the color-dipole approach employing various saturation models. We show that greatest sensitivity to saturation effects is reached at very forward rapidities for pp collisions at LHC (\\sqrt{s}=14 TeV). The ratio of direct-photon to pion production can be about 20-10 (at \\eta=7-8). Therefore, direct photon production at forward rapidities should provide a rather clean probe. We calculate the rapidity dependence of the invariant cross-section and find some peculiar enhancement at forward rapidities which is more pronounced for direct photon production. We show that this peak is further enhanced by saturation effects. We provide predictions for the nuclear modification factor R_{pA} for pions and direct photon production in pA collisions at LHC energy at midrapidity. We show within various saturation models that the pion Cronin enhancement at RHIC is replaced by a moderate suppression at LHC energy at midrapidity due to gluon shadowing effects. Cronin enhancement of direct photons can survive at LHC energy within models with a larger saturation scale.

  14. Effects of gaze direction, head orientation and valence of facial expression on amygdala activity.

    PubMed

    Sauer, Andreas; Mothes-Lasch, Martin; Miltner, Wolfgang H R; Straube, Thomas

    2014-08-01

    There is increasing evidence for a role of the amygdala in processing gaze direction and emotional relevance of faces. In this event-related functional magnetic resonance study we investigated amygdala responses while we orthogonally manipulated head direction, gaze direction and facial expression (angry, happy and neutral). This allowed us to investigate effects of stimulus ambiguity, low-level factors and non-emotional factors on amygdala activation. Averted vs direct gaze induced increased activation in the right dorsal amygdala regardless of facial expression and head orientation. Furthermore, valence effects were found in the ventral amygdala and strongly dependent on head orientation. We observed enhanced activation to angry and neutral vs happy faces for observer-directed faces in the left ventral amygdala while the averted head condition reversed this pattern resulting in increased activation to happy as compared to angry and neutral faces. These results suggest that gaze direction drives specifically dorsal amygdala activation regardless of facial expression, low-level perceptual factors or stimulus ambiguity. The role of the amygdala is thus not restricted to the detection of potential threat, but has a more general role in attention processes. Furthermore, valence effects are associated with activation of the ventral amygdala and strongly influenced by non-emotional factors. PMID:23946006

  15. 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.

  16. 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

  17. 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.

  18. New directional signatures from the nonrelativistic effective field theory of dark matter

    NASA Astrophysics Data System (ADS)

    Kavanagh, Bradley J.

    2015-07-01

    The framework of nonrelativistic effective field theory (NREFT) aims to generalize the standard analysis of direct detection experiments in terms of spin-dependent and spin-independent interactions. We show that a number of NREFT operators lead to distinctive new directional signatures, such as prominent ringlike features in the directional recoil rate, even for relatively low-mass weakly interacting massive particles. We discuss these signatures and how they could affect the interpretation of future results from directional detectors. We demonstrate that considering a range of possible operators introduces a factor of 2 uncertainty in the number of events required to confirm the median recoil direction of the signal. Furthermore, using directional detection, it is possible to distinguish the more general NREFT interactions from the standard spin-indenpendent/spin-dependent interactions at the 2 ? level with O (100 - 500 ) events. In particular, we demonstrate that for certain NREFT operators directional sensitivity provides the only method of distinguishing them from these standard operators, highlighting the importance of directional detectors in probing the particle physics of dark matter.

  19. 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.

  20. The direct and indirect effects of corruption on motor vehicle crash deaths.

    PubMed

    Hua, Law Teik; Noland, Robert B; Evans, Andrew W

    2010-11-01

    Recent empirical research has found that there is an inverted U-shaped or Kuznets relationship between income and motor vehicle crash (MVC) deaths, such that MVC deaths increase as national income increases and decrease after reaching a critical level. Corruption has been identified as one of the underlying factors that could affect this relationship, primarily by undermining institutional development and effective enforcement schemes. The total effect of corruption can be decomposed into two components, a direct and an indirect effect. The direct effect measures the immediate impact of corruption on MVC deaths by undermining effective enforcement and regulations, while the indirect effect captures the impact of corruption on hindering increases in per capita income and the consequent impact of reduced income on MVC deaths. By influencing economic growth, corruption can lead to an increase or decrease in MVC deaths depending on the income level. Using data from 60 countries between 1982 and 2003, these effects are estimated using linear panel and fixed effects negative binomial models. The estimation results suggest that corruption has different direct effects for less developed and highly developed countries. It has a negative (decreasing) effect on MVC deaths for less developed countries and a positive (increasing) effect on MVC deaths for highly developed countries. For highly developed countries, the total effect is positive at lower per capita income levels, but decreases with per capita income and becomes negative at per capita income levels of about US$ 38,248. For less developed countries, the total effect is negative within the sample range and decreases with increased per capita income. In summary, the results of this study suggest that reduction of corruption is likely a necessary condition to effectively tackle road safety problems. PMID:20728645

  1. High-dynamic range interferometric astronomical imaging in the presence of direction dependent effects

    NASA Astrophysics Data System (ADS)

    Bhatnagar, S.

    2012-10-01

    Modern high sensitivity radio interferometric telescopes use ultra wide-band receivers on a large number of antenna elements to achieve the capability of imaging dynamic ranges in excess of 1:1,000,000. In practice, the imaging performance is limited by instrumental and ionospheric/atmospheric effects that corrupt the recorded data. Many of these effects are directionally dependent and vary with time and frequency. Correcting for them is therefore fundamentally more difficult and these effects have been ignored in classical image reconstruction algorithms. Few attempts in the past to correct for these effects in the image-domain did not deliver the required accuracy. Recent developments in new algorithms that can account for such direction dependent effects show promising results. In this paper I give a general mathematical description of these techniques, show that the resulting algorithms are more optimal in terms of imaging performance and computing requirements and show some results.

  2. A Meta-Analysis of Site-Specific Effects of Cathodal Transcranial Direct Current Stimulation on Sensory Perception and Pain

    PubMed Central

    Vaseghi, Bita; Zoghi, Maryam; Jaberzadeh, Shapour

    2015-01-01

    The primary aim of our meta-analysis was to evaluate the effects of cathodal transcranial direct current stimulation (c-tDCS) on sensory and pain thresholds (STh and PTh) in healthy individuals and pain level (PL) in patients with chronic pain. Electronic databases were searched for c-tDCS studies. Methodological quality was evaluated using the PEDro and Downs and Black (D&B) assessment tools. C-tDCS of the primary motor cortex (S1) increases both STh (P<0.001, effect size of 26.84%) and PTh (P<0.001, effect size of 11.62%). In addition, c-tDCS over M1 led to STh increase (P<0.005, effect size of 30.44%). Likewise, PL decreased significantly in the patient group following application of c-tDCS. The small number of studies precluded subgroup analysis. Nevertheless, meta-analysis showed that in all groups (except c-tDCS of S1) active c-tDCS and sham stimulation produced significant differences in STh/PTh in healthy and PL in patient group. This review provides evidence for the site-specific effectiveness of c-tDCS in increasing STh/PTh in healthy individuals and decreasing PL in patients with chronic pain. However, due to small sample sizes in the included studies, our results should be interpreted with caution. Given that the level of blinding was not considered in the inclusion criteria, the results of the current study should be interpreted with caution. PMID:25978673

  3. Nonlinear Effects of Nanoparticles: Biological Variability From Hormetic Doses, Small Particle Sizes, and Dynamic Adaptive Interactions

    PubMed Central

    Bell, Iris R.; Ives, John A.; Jonas, Wayne B.

    2014-01-01

    Researchers are increasingly focused on the nanoscale level of organization where biological processes take place in living systems. Nanoparticles (NPs, e.g., 1–100 nm diameter) are small forms of natural or manufactured source material whose properties differ markedly from those of the respective bulk forms of the “same” material. Certain NPs have diagnostic and therapeutic uses; some NPs exhibit low-dose toxicity; other NPs show ability to stimulate low-dose adaptive responses (hormesis). Beyond dose, size, shape, and surface charge variations of NPs evoke nonlinear responses in complex adaptive systems. NPs acquire unique size-dependent biological, chemical, thermal, optical, electromagnetic, and atom-like quantum properties. Nanoparticles exhibit high surface adsorptive capacity for other substances, enhanced bioavailability, and ability to cross otherwise impermeable cell membranes including the blood-brain barrier. With super-potent effects, nano-forms can evoke cellular stress responses or therapeutic effects not only at lower doses than their bulk forms, but also for longer periods of time. Interactions of initial effects and compensatory systemic responses can alter the impact of NPs over time. Taken together, the data suggest the need to downshift the dose-response curve of NPs from that for bulk forms in order to identify the necessarily decreased no-observed-adverse-effect-level and hormetic dose range for nanoparticles. PMID:24910581

  4. Effective medium theories for irregular fluffy structures: aggregation of small particles

    NASA Astrophysics Data System (ADS)

    Voshchinnikov, Nikolai V.; Videen, Gorden; Henning, Thomas

    2007-07-01

    The extinction efficiencies as well as the scattering properties of particles of different porosity are studied. Calculations are performed for porous pseudospheres with small size (Rayleigh) inclusions using the discrete dipole approximation. Five refractive indices of materials covering the range from 1.20+0.00i to 1.75+0.58i were selected. They correspond to biological particles, dirty ice, silicate, and amorphous carbon and soot in the visual part of the spectrum. We attempt to describe the optical properties of such particles using Lorenz-Mie theory and a refractive index found from some effective medium theory (EMT) assuming the particle is homogeneous. We refer to this as the effective model. It is found that the deviations are minimal when utilizing the EMT based on the Bruggeman mixing rule. Usually the deviations in the extinction factor do not exceed ˜5% for particle porosity P=0-0.9 and size parameters xporous=2?rs,porous/??25. The deviations are larger for scattering and absorption efficiencies and smaller for particle albedo and the asymmetry parameter. Our calculations made for spheroids confirm these conclusions. Preliminary consideration shows that the effective model represents the intensity and polarization of radiation scattered by fluffy aggregates quite well. Thus the effective models of spherical and nonspherical particles can be used to significantly simplify the computations of the optical properties of aggregates containing only Rayleigh inclusions.

  5. Adverse effects of small-volume red blood cell transfusions in the neonatal population

    PubMed Central

    2014-01-01

    Background Adverse transfusion reactions in the neonatal population are poorly understood and defined. The incidence and pattern of adverse effects due to red blood cell (RBC) transfusion are not well known, and there has been no systematic review of published adverse events. RBC transfusions continue to be linked to the development of morbidities unique to neonates, including chronic lung disease, retinopathy of prematurity, intraventricular haemorrhage and necrotising enterocolitis. Uncertainties about the exact nature of risks alongside benefits of RBC transfusion may contribute to evidence of widespread variation in neonatal RBC transfusion practice. Our review aims to describe clinical adverse effects attributed to small-volume (10–20 mL/kg) RBC transfusions and, where possible, their incidence rates in the neonatal population through the systematic identification of all relevant studies. Methods A comprehensive search of the following bibliographic databases will be performed: MEDLINE (PubMed/OVID which includes the Cochrane Library) and EMBASE (OVID). The intervention of interest is small-volume (10–20 mL/kg) RBC transfusions in the neonatal population. We will undertake a narrative synthesis of the evidence. If clinical similarity and data quantity and quality permit, we will also carry out meta-analyses on the listed outcomes. Discussion This systematic review will identify and synthesise the reported adverse effects and associations of RBC transfusions in the neonatal population. We believe that this systematic review is timely and will make a valuable contribution to highlight an existing research gap. Trial Registration PROSPERO, CRD42013005107 http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42013005107 PMID:25143009

  6. Coherent-backscatter effect - A vector formulation accounting for polarization and absorption effects and small or large scatterers

    NASA Technical Reports Server (NTRS)

    Peters, Kenneth J.

    1992-01-01

    Previous theoretical work on the coherent-backscatter effect in the context of speckle time autocorrelation has gone beyond the diffusion approximation and the assumption of isotropic (point) scatterers. This paper extends the theory to include the effects of polarization and absorption, and to give the angular line shape. The results are expressions for angular variations valid for small and large scatterers and linear and circular polarizations, in lossless or lossy media. Calculations show that multiple anisotropic scattering results in the preservation of incident polarization. Application to a problem in radar astronomy is considered. It is shown that the unusual radar measurements (high reflectivity and polarization ratios) of Jupiter's icy Galilean satellites can be explained by coherent backscatter from anisotropic (forward) scatterers.

  7. 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.

  8. High frequency directivity effect for a Mw 4.1 earthquake (Barcelonnette event, 2012), widely felt by the population

    NASA Astrophysics Data System (ADS)

    Courboulex, Francoise; Dujardin, Alain; Vallée, Martin; Delouis, Bertrand; Deschamps, Anne; Sira, Christophe; Maron, Christophe

    2013-04-01

    Can the directivity effect of a rupture process be detected by the population 100 km away for a moderate size Mw 4.1 earthquake? The February 26th 2012, earthquake that occurred in the French Alps proved that it can ! During the night of February 26, 2012, the inhabitants and winter holidaymakers of the Vallée de l'Ubaye in the French Alps were woken by a brutal vibration due to an earthquake. This event that occurred at 8km depth was widely felt in the epicentral area and caused some light damage to houses (25 chimneys were broken, and a great deal of non-structural damage was detected). This event occurred in a mountainous area populated only by villages or small cities, the two largest cities (Grenoble and Nice) being both situated about 100 km from the epicenter. A rapid inspection of the macroseismic intensity values (collected by the BCSF) estimated in both cities immediately proved the fact that this event was much more felt in Nice and its surroundings than in Grenoble. This discrepancy is very well correlated with Peak Ground Acceleration (PGA) values measured on the 16 accelerograms of the RAP network (Réseau Accélérométrique Permanent Français) in the two cities, the values measured in Grenoble being in average 8 times smaller than the one measured in Nice (smaller PGA value in Nice/ smaller PGA value in Grenoble, on good rock sites). A factor 10 was also observed inside both cities due to site effects, which results in a variability that reaches a factor 60 between the smallest and the largest PGA values recorded at 100km. In order to explain these observations, we selected French and Italian broad band stations in different azimuths and deconvolved the mainshock velocity recordings by the one of an aftershock (Mw 2.3) taken as empirical Green's function. The apparent source time functions obtained clearly show that the Barcelonnette event had a strong directivity effect of its rupture process. We found, using a simple linear source model inversion that the rupture propagated toward the direction N155° during 0.85 seconds on a 1.9-km-long fault. This direction is coherent with one nodal plane of the focal mechanism we have found for this event. This study highlights the fact that, even for moderate size earthquakes, directivity effect plays a main role in the generation of ground motions and also in the spatial distribution of macroseismic intensities. This last point has to be taken into account for the analysis of historical earthquakes, because it may lead to an over- or under-estimation of the magnitude.

  9. 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

  10. Effect of doctoring on the performance of direct gravure printing for conductive microfine lines

    NASA Astrophysics Data System (ADS)

    Phuong Hoang, Huu; Lim Ko, Sung

    2015-11-01

    Printed electronics on flexible thin film has challenged and inspired the motivation of scientists in many fields. Among traditional printing methods such as stamping, flexography, offset, screen-printing, and inkjet, the gravure method is expected to reduce costs and increase productivity for printed electronics applications. In this research, conductive microfine line patterns, which print out the layer as microelectrodes for organic thin film transistor (OTFT) or microcircuit lines, have been designed with different size widths and lengths according to the printing direction, MD (machine direction), and CMD (cross machine direction, or transverse direction, TD, which is popularly used in industry). These patterns were printed with nano-particle silver ink on PI thin film, but had some serious problems with discontinuity and less filling after doctoring and printing. To solve these problems, the doctoring effect is investigated and analyzed before ink transferring, mainly in the printing machine direction and CMD. The uniformity and accuracy of the microfine lines are controlled and improved in order to achieve the stability of the printed pattern lines. In this work, considering the effect of the deflection of the doctor blade in the CMD (transverse direction), a doctoring model in the CMD is proposed and compared with the experimental result. Experimentally, proper doctoring conditions like blade stiffness and doctoring pressure are sought.

  11. Novel methods to optimize the effects of transcranial direct current stimulation: a systematic review of transcranial direct current stimulation patents.

    PubMed

    Malavera, Alejandra; Vasquez, Alejandra; Fregni, Felipe

    2015-11-01

    Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that has been extensively studied. While there have been initial positive results in some clinical trials, there is still variability in tDCS results. The aim of this article is to review and discuss patents assessing novel methods to optimize the use of tDCS. A systematic review was performed using Google patents database with tDCS as the main technique, with patents filling date between 2010 and 2015. Twenty-two patents met our inclusion criteria. These patents attempt to address current tDCS limitations. Only a few of them have been investigated in clinical trials (i.e., high-definition tDCS), and indeed most of them have not been tested before in human trials. Further clinical testing is required to assess which patents are more likely to optimize the effects of tDCS. We discuss the potential optimization of tDCS based on these patents and the current experience with standard tDCS. PMID:26415093

  12. Effect of small-scale heterogeneities on interpretation of crustal compositions exemplified by a layered anorthosite

    NASA Astrophysics Data System (ADS)

    Semprich, J.; Vrijmoed, J. C.

    2015-02-01

    The composition of the lower crust has a significant effect on geodynamic processes because it influences physical rock properties such as densities and seismic velocities. Compositional differences in lower crustal rocks are potentially large and exist on the scales of centimeters up to kilometers resulting in non-unique seismic and gravity data. While larger heterogeneities can be detected as reflections on seismic profiles, irregular small-scale compositional variations are not likely to be discovered, but will influence the averaged seismic velocities and densities of an area. The extent and effects of such small-scale heterogeneities are explored on an exposed high-grade layered anorthositic body by providing a detailed field map, petrological descriptions, pycnometry measurements as well as whole rock and mineral analyses combined with thermodynamic phase equilibria calculations. To evaluate the results of our thermodynamic calculations, densities and mineral modes obtained from the modeled phase equilibria are compared to measured densities and estimated mineral modes from rock samples. The proportion of mafic to ultramafic (plagioclase-poor) rocks in the mapped field area amounts to 10-15% but higher proportions of these rock types in the lower crust are feasible. To further study the effects of compositional variations, we have generated mixtures of mafic to ultramafic and anorthositic/intermediate rocks until the average properties of these mixtures are comparable to those of mafic granulites (3000-3100 kg/m3; 7.1-7.3 km/s). Mixtures of anorthosite with 40-45% and of tonalite with 50-60% high-grade mafic to ultramafic rocks yield average densities and seismic velocities similar to mafic granulites although they still contain 50-60 vol.% plagioclase. Hence small-scale mixing of certain rock types may result in the overestimation of the proportion of mafic (garnet) granulites in the lithologic interpretation of crustal compositions from seismic data. Since the transition to eclogite-facies in plagioclase-rich rocks is shifted to higher pressures and anorthositic/intermediate eclogites yield lower densities, a lower crust with higher modal amounts of plagioclase may not always provide the significant densification needed for certain geodynamic settings (e.g. delamination or subsidence).

  13. Connecting dark matter UV complete models to direct detection rates via effective field theory

    NASA Astrophysics Data System (ADS)

    D'Eramo, Francesco; Procura, Massimiliano

    2015-04-01

    Direct searches for WIMPs are sensitive to physics well below the weak scale. In the absence of light mediators, it is fruitful to apply an Effective Field Theory (EFT) approach accounting only for dark matter (DM) interactions with Standard Model (SM) fields. We consider a singlet fermion WIMP and effective operators up to dimension 6 which are generated at the mass scale of particles mediating DM interactions with the SM. We perform a one-loop Renormalization Group Evolution (RGE) analysis, evolving these effective operators from the mediators mass scale to the nuclear scales probed by direct searches. We apply our results to models with DM velocity-suppressed interactions, DM couplings only to heavy quarks, leptophilic DM and Higgs portal, which without our analysis would not get constrained from direct detection bounds. Remarkably, a large parameter space region for these models is found to be excluded as a consequence of spin-independent couplings induced by SM loops. In addition to these examples, we stress that more general renormalizable models for singlet fermion WIMP can be matched onto our EFT framework, and the subsequent model-independent RGE can be used to compute direct detection rates. Our results allow us to properly connect the different energy scales involved in constraining WIMP models, and to combine information from direct detection with other complementary searches, such as collider and indirect detection.

  14. The effects of training on errors of perceived direction in perspective displays

    NASA Technical Reports Server (NTRS)

    Tharp, Gregory K.; Ellis, Stephen R.

    1990-01-01

    An experiment was conducted to determine the effects of training on the characteristic direction errors that are observed when subjects estimate exocentric directions on perspective displays. Changes in five subjects' perceptual errors were measured during a training procedure designed to eliminate the error. The training was provided by displaying to each subject both the sign and the direction of his judgment error. The feedback provided by the error display was found to decrease but not eliminate the error. A lookup table model of the source of the error was developed in which the judgement errors were attributed to overestimates of both the pitch and the yaw of the viewing direction used to produce the perspective projection. The model predicts the quantitative characteristics of the data somewhat better than previous models did. A mechanism is proposed for the observed learning, and further tests of the model are suggested.

  15. Direct and semidirect aerosol effects of Southern African biomass burning aerosol

    SciTech Connect

    Sakaeda, Naoko; Wood, Robert; Rasch, Philip J.

    2011-06-21

    The direct and semi-direct radiative effects of biomass burning aerosols from Southern African fires during July-October are investigated using 20 year runs of the Community Atmospheric Model (CAM) coupled to a slab ocean model. The aerosol optical depth is constrained using observations in clear skies from MODIS and for aerosol layers above clouds from CALIPSO. Over the ocean, where the absorbing biomass burning aerosol layers are primarily located above cloud, negative top of atmosphere (TOA) semi-direct radiative effects associated with increased low cloud cover dominate over a weaker positive all-sky direct radiative effect (DRE). In contrast, over the land where the aerosols are often below or within cloud layers, reductions in cloud liquid water path (LWP) lead to a positive semi-direct radiative effect that dominates over a near-zero DRE. Over the ocean, the cloud response can be understood as a response to increased lower tropospheric stability (LTS) which is caused both by aerosol absorptive warming in overlying layers and surface cooling in response to direct aerosol forcing. The ocean cloud changes are robust to changes in the cloud parameterization (removal of the hard-wired dependence of clouds on LTS), suggesting that they are physically realistic. Over land where cloud cover changes are minimal, decreased LWP is consistent with weaker convection driven by increased static stability. Over the entire region the overall TOA radiative effect from the biomass burning aerosols is almost zero due to opposing effects over the land and ocean. However, the surface forcing is strongly negative requiring a reduction in precipitation. This is primarily realized through reductions in convective precipitation on both the southern and northern flanks of the convective precipitation region spanning the equatorial rainforest and the ITCZ in the southern Sahel. The changes are consistent with the low-level aerosol forced cooling pattern. The results highlight the importance of semi-direct radiative effects and precipitation responses for determining the climatic effects of aerosols in the African region.

  16. Direct and indirect effects of interdental hygiene in a clinical trial.

    PubMed

    Tu, Y-K; Jackson, M; Kellett, M; Clerehugh, V

    2008-11-01

    Many randomized controlled trials (RCTs) in dental research test the efficacy of interventions on more than one outcome variable. Univariate methods, such as the t test or analysis of covariance, cannot evaluate the efficacy of interventions on multiple outcomes simultaneously. The aim of this study was to use structural equation modeling (SEM) to re-analyze a RCT, comparing the effects of pre-curved interdental brushes and flossing on probing pocket depth (PPD), plaque indices, and bleeding on probing (BOP) measured at baseline, intermediate, and final examinations. Results of SEM showed that the observed greater reduction in PPD and BOP in persons using interdental brushing than in those flossing is due mainly to the greater efficiency in plaque removal with the interdental brushes (indirect effect) rather than to the compression of the interdental papillae (direct effect). In contrast, smokers showed less BOP at baseline but also less improvement in BOP through direct effects. PMID:18946011

  17. Perceptual training effects on anticipation of direct and deceptive 7-m throws in handball.

    PubMed

    Alsharji, Khaled E; Wade, Michael G

    2016-01-01

    We examined the effectiveness of perceptual training on the performance of handball goalkeepers when anticipating the direction of both direct and deceptive 7-m throws. Skilled goalkeepers were assigned equally to three matched-ability groups based on their pre-test performance: a perceptual training group (n = 14) received video-based perceptual training, a placebo training group (n = 14) received video-based regular training and a control group received no training. Participants in the perceptual training group significantly improved their performance compared to both placebo and control groups; however, anticipation of deceptive throws improved less than for direct throws. The results confirm that although anticipating deception in handball is a challenging task for goalkeepers, task-specific perceptual training can minimise its effect and improve performance. PMID:25917061

  18. 78 FR 9938 - U.S.-Korea Free Trade Agreement: Effects on U.S. Small and Medium-Sized Enterprises; Institution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-12

    ...Agreement: Effects on U.S. Small and Medium-Sized Enterprises; Institution of Investigation...Agreement: Effects on U.S. Small and Medium-Sized Enterprises. DATES: February...william.gearhart@usitc.gov). The media should contact Margaret...

  19. Simulating the Effect of Space Vehicle Environments on Directional Solidification of a Binary Alloy

    NASA Technical Reports Server (NTRS)

    Westra, D. G.; Heinrich, J. C.; Poirier, D. R.

    2003-01-01

    Space microgravity missions are designed to provide a microgravity environment for scientific experiments, but these missions cannot provide a perfect environment, due to vibrations caused by crew activity, on-board experiments, support systems (pumps, fans, etc.), periodic orbital maneuvers, and water dumps. Therefore, it is necessary to predict the impact of these vibrations on space experiments, prior to performing them. Simulations were conducted to study the effect of the vibrations on the directional solidification of a dendritic alloy. Finite element ca!cu!attie?ls were dme with a simd2titcr based on a continuum model of dendritic solidification, using the Fractional Step Method (FSM). The FSM splits the solution of the momentum equation into two steps: the viscous intermediate step, which does not enforce continuity; and the inviscid projection step, which calculates the pressure and enforces continuity. The FSM provides significant computational benefits for predicting flows in a directionally solidified alloy, compared to other methods presently employed, because of the efficiency gains in the uncoupled solution of velocity and pressure. finite differences, arises when the interdendritic liquid reaches the eutectic temperature and concentration. When a node reaches eutectic temperature, it is assumed that the solidification of the eutectic liquid continues at constant temperature until all the eutectic is solidified. With this approach, solidification is not achieved continuously across an element; rather, the element is not considered solidified until the eutectic isotherm overtakes the top nodes. For microgravity simulations, where the convection is driven by shrinkage, it introduces large variations in the fluid velocity. When the eutectic isotherm reaches a node, all the eutectic must be solidified in a short period, causing an abrupt increase in velocity. To overcome this difficulty, we employed a scheme to numerically predict a more accurate value for the rate of change of fraction of liquid as the liquid in an element solidifies. The new method enables us to contrast results of simulations in which the alloy is subjected to no gravity or a steady-state acceleration versus simulations when the alloy is subjected to vibration disturbances; therefore, the effect of vibration disturbances can be assessed more accurately. To assess the impact of these vibration-perturbations, transient accelerometer data from a space shuttle mission are used as inputs for the simulation model. These on-orbit acceleration data were obtained from the Microgravity Science Division at Glenn Research Center (GRC- MSD) and are applied to the buoyancy term of the momentum equation in a simulation of a Pb-5.8 wt. % Sb alloy that solidifies in a thermal gradient of 4000 K/m and a translation velocity of 3 p d s . Figure 2 shows the vertical velocity of a node that begins in the all-liquid region and subsequently solidifies; the vibrations are applied at 5000 seconds in this simulation. An important difficulty, common to all solidification models based on finite elements or 2 The magnitudes of the velocity oscillations that are vibration-induced are very small and acceptable. The biggest concern is whether the concentration of the liquid near the dendrite tips is distorted because of the vibration-induced perturbations. Results for this case show no concentration oscillations present in the all-liquid region.

  20. Small slope tilts caused by meteorological effects and vital processes of trees on a wooded slope in Hidegvíz Valley, Hungary

    NASA Astrophysics Data System (ADS)

    Mentes, Gyula; Bódis, Virág Bereniké; Vig, Péter

    2014-02-01

    Long-term measurements were carried out to investigate the relationship between ground tilts and variations of meteorological (temperature, precipitation) and hydrological (soil moisture content) parameters in the area of the Sopron Mountains, on a wooded slope of the Hidegvíz Valley, Hungary. The connection between surface tilts and the vital processes of the trees was also studied on the basis of the reference evapotranspiration calculated for the study area. Long- and short-term variations were separated. A long-term ground temperature change of 1 °C caused a 4 ?rad tilt in the SE direction. Short-term temperature effects can be neglected. The fluctuation of temperature around the freezing point caused tilts of about 10 ?rad °C- 1. The soil water content variation had the largest effect on the ground tilt (0.5 ?rad mm- 1). Its contribution to the total ground tilt in the investigated period was about 70 ?rad (65% of the total tilt of 107 ?rad) toward the SSE. The contribution of the wind speed to the ground tilt was about 20 ?rad m s- 1 toward the SSE depending on the water content of the soil. The wind did not cause a permanent ground tilt. The magnitude of the daily tilt variations in the active growing period of trees, from March to October, is 1-2 ?rad while in the dormant period (with no canopy) the tilt variations were less than 0.4 ?rad. The admittances between the evapotranspiration and the ground tilts were 0.3-0.5 ?rad mm- 1 and 0.1-0.2 ?rad mm- 1 in the active and dormant period of the trees, respectively. These small effects superimposed on each other can significantly contribute to slope failures. The results of this study provide information which can be useful in the modelling of landslide movements and for the mitigation of landslide hazards.

  1. Cytotoxic Effects of Fascaplysin against Small Cell Lung Cancer Cell Lines

    PubMed Central

    Hamilton, Gerhard

    2014-01-01

    Fascaplysin, the natural product of a marine sponge, exhibits anticancer activity against a broad range of tumor cells, presumably through interaction with DNA, and/or as a highly selective cyclin-dependent kinase 4 (CDK4) inhibitor. In this study, cytotoxic activity of fascaplysin against a panel of small cell lung cancer (SCLC) cell lines and putative synergism with chemotherapeutics was investigated. SCLC responds to first-line chemotherapy with platinum-based drugs/etoposide, but relapses early with topotecan remaining as the single approved therapeutic agent. Fascaplysin was found to show high cytotoxicity against SCLC cells and to induce cell cycle arrest in G1/0 at lower and S-phase at higher concentrations, respectively. The compound generated reactive oxygen species (ROS) and induced apoptotic cell death in the chemoresistant NCI-H417 SCLC cell line. Furthermore, fascaplysin revealed marked synergism with the topoisomerase I-directed camptothecin and 10-hydroxy-camptothecin. The Poly(ADP-ribose)-Polymerase 1 (PARP1) inhibitor BYK 204165 antagonized the cytotoxic activity of fascaplysin, pointing to the involvement of DNA repair in response to the anticancer activity of the drug. In conclusion, fascaplysin seems to be suitable for treatment of SCLC, based on high cytotoxic activity through multiple routes of action, affecting topoisomerase I, integrity of DNA and generation of ROS. PMID:24608973

  2. Mild and cost-effective green fluorescent protein purification employing small synthetic ligands.

    PubMed

    Pina, Ana Sofia; Dias, Ana Margarida G C; Ustok, Fatma Isik; El Khoury, Graziella; Fernandes, Cláudia S M; Branco, Ricardo J F; Lowe, Christopher R; Roque, A Cecília A

    2015-10-30

    The green fluorescent protein (GFP) is a useful indicator in a broad range of applications including cell biology, gene expression and biosensing. However, its full potential is hampered by the lack of a selective, mild and low-cost purification scheme. In order to address this demand, a novel adsorbent was developed as a generic platform for the purification of GFP or GFP fusion proteins, giving GFP a dual function as reporter and purification tag. After screening a solid-phase combinatorial library of small synthetic ligands based on the Ugi-reaction, the lead ligand (A4C7) selectively recovered GFP with 94% yield and 94% purity under mild conditions and directly from Escherichia coli extracts. Adsorbents containing the ligand A4C7 maintained the selectivity to recover other proteins fused to GFP. The performance of A4C7 adsorbents was compared with two commercially available methods (immunoprecipitation and hydrophobic interaction chromatography), confirming the new adsorbent as a low-cost viable alternative for GFP purification. PMID:26422306

  3. Effects of spherical inclusions on scattering properties of small ice cloud particles

    NASA Astrophysics Data System (ADS)

    Hong, Gang; Minnis, Patrick

    2015-04-01

    The single-scattering properties of small ice crystals containing four types of spherical inclusions, ammonium sulfate (NH4)2SO4, ammonium nitrate NH3NO3, air bubbles, and soot, are investigated at 0.65 and 2.13 µm. Small, randomly oriented hexagonal ice columns with spherical inclusions that are randomly distributed with standard gamma size distributions in the columns are considered in the present study. Ice crystals with inclusions of (NH4)2SO4 and NH3NO3 essentially have the same features due to their similar refractive indices. Nonzero scattering matrix elements are sensitive to inclusion type and amount, and show differences between 0.65 and 2.13 µm. The extinction efficiency Qe of small ice crystals at 0.65 µm is near 2.0 and essentially unaffected by variations in inclusion volume, in contrast to strong influences of inclusion amount on Qe at 2.13 µm. The single-scattering albedo ?0 of ice crystals, nearly equal to 1.0, is not affected by inclusions of (NH4)2SO4, NH3NO3, and air bubbles. Soot inclusions strongly affect ?0, which decreases to about 0.5 with increasing soot amounts. The asymmetry factor g is substantially affected by (NH4)2SO4, NH3NO3, and soot and the variations in their amounts. Full Stokes parameters of cirrus clouds consisting of uniform hexagonal ice columns with inclusions are computed using a polarized radiative transfer model. Sensitivities of light intensity and polarization of cirrus clouds to types and amounts of inclusions and cirrus cloud optical thicknesses are found to depend on wavelength. The present results suggest that different types of inclusions for small ice crystals should be considered when developing realistic ice crystal optical properties, and that light intensity and polarization of cirrus clouds and their angular distribution features, in the absence of other effects such as cavities and surface roughness, imply the potential for identifying pure ice crystals from those with aerosol inclusions.

  4. Effects of health and safety problem recognition on small business facility investment

    PubMed Central

    2013-01-01

    Objectives This study involved a survey of the facility investment experiences, which was designed to recognize the importance of health and safety problems, and industrial accident prevention. Ultimately, we hope that small scale industries will create effective industrial accident prevention programs and facility investments. Methods An individual survey of businesses’ present physical conditions, recognition of the importance of the health and safety problems, and facility investment experiences for preventing industrial accidents was conducted. The survey involved 1,145 business operators or management workers in small business places with fewer than 50 workers in six industrial complexes. Results Regarding the importance of occupational health and safety problems (OHS), 54.1% said it was “very important”. Received technical and financial support, and industrial accidents that occurred during the past three years were recognized as highly important for OHS. In an investigation regarding facility investment experiences for industrial accident prevention, the largest factors were business size, greater numbers of industrial accidents, greater technical and financial support received, and greater recognition of the importance of the OHS. The related variables that decided facility investment for industry accident prevention in a logistic regression analysis were the experiences of business facilities where industrial accidents occurred during the past three years, received technical and financial support, and recognition of the OHS. Those considered very important were shown to be highly significant. Conclusions Recognition of health and safety issues was higher when small businesses had experienced industrial accidents or received financial support. The investment in industrial accidents was greater when health and safety issues were recognized as important. Therefore, the goal of small business health and safety projects is to prioritize health and safety issues in terms of business management and recognition of importance. Therefore, currently various support projects are being conducted. However, there are issues regarding the limitations of the target businesses and inadequacies in maintenance and follow-up. Overall, it is necessary to provide various incentives for onsite participation that can lead to increased recognition of health and safety issues and practical investments, while perfecting maintenance and follow up measures by thoroughly revising existing operating systems. PMID:24472180

  5. Numerical investigation of the geometrical effects on UHMWPE flow characteristics in small aperture spinneret orifice

    NASA Astrophysics Data System (ADS)

    Qin, Shengxue; Zhang, Zhanhuan; Xu, Xingming; Liu, Jie; Liu, Hong

    2015-07-01

    Due to high viscosity of the ultra-high molecular weight polyethylene (UHMWPE), it is difficult for the melt UHMWPE to flow through the small aperture spinneret orifice in the melt spinning forming process. The geometrical parameters of the spinneret orifice become critical to the melt spinning process. Based on the theory of polymer rheology, the finite element model of UHMWPE melt spinning had been developed by using POLYFLOW, and the length-to-diameter ratio and taper angle of the spinneret orifice effects on the UHMWPE melt flow characters were discussed. The results show that suitable length-to-diameter ratio and taper angle are helpful for the compactness and flow stability of the melt.

  6. Selective vapor phase sensing of small molecules using biofunctionalized field effect transistors

    NASA Astrophysics Data System (ADS)

    Hagen, Joshua A.; Kim, Sang Nyon; Kelley-Loughnane, Nancy; Naik, Rajesh R.; Stone, Morley O.

    2011-05-01

    This work details a proof of concept study for vapor phase selective sensing using a strategy of biorecognition elements (BRE) integrated into a zinc oxide field effect transistor (ZnO FET). ZnO FETs are highly sensitive to changes to the environment with little to no selectivity. Addition of a biorecognition element retains the sensitivity of the device while adding selectivity. The DNA aptamer designed to bind the small molecule riboflavin was covalently integrated into the ZnO FET and detects the presence of 116 ppb of riboflavin in a nitrogen atmosphere by a change in current. The unfunctionalized ZnO FET shows no response to this same concentrations of riboflavin, showing that the aptamerbinding strategy may be a promising strategy for vapor phase sensing.

  7. DNA aptamer functionalized zinc oxide field effect transistors for liquid state selective sensing of small molecules

    NASA Astrophysics Data System (ADS)

    Hagen, Joshua A.; Kim, Sang N.; Bayraktaroglu, Burhan; Kelley-Loughnane, Nancy; Naik, Rajesh R.; Stone, Morley O.

    2010-08-01

    In this work, we show the use of single stranded DNA aptamers as selective biorecognition elements in a sensor based on a field effect transistor (FET) platform. Aptamers are chemically attached to the semiconducting material in the FET through the use of linker molecules and confirmed through atomic force microscopy and positive target detection. Highly selective sensing of a small molecule, riboflavin is shown down to the nano-molar level in zinc oxide FET and micro-molar level in a carbon nanotube FET. High selectivity is determined through the use of negative control target molecules with similar molecular structures as the positive control targets with little to no sensor response. The goal of this work is to develop a sensor platform where biorecognition elements can be used to functionalize an array of transistors for simultaneous sensing of multiple targets in biological fluids.

  8. The Effect of Adding Small Percentages of Finely Ground Metals to Enamels

    E-print Network

    Pyle, Glenn L.

    1912-05-15

    was p l a c e d the ground f r i t t f r e e from metal and in the o ther the mixture o f ground f r i t t and m e t a l . Over the mouth o f the boxes f i n e cheese c l o t h was p l a c e d and bound on with rubber bands . Two o f the s t e e l p...Works | The University of Kansas Pre-1923 Dissertations and Theses Collection The Effect of Adding Small Percentages of Finely Ground Metals to Enamels May 15th, 1912 by Glenn L. Pyle This work was digitized by the Scholarly Communications program staff in the KU...

  9. Diffraction and fringing field effects in small pixel liquid crystal devices with homeotropic alignment

    NASA Astrophysics Data System (ADS)

    Vanbrabant, Pieter J. M.; Beeckman, Jeroen; Neyts, Kristiaan; Willman, Eero; Fernandez, F. Anibal

    2010-10-01

    Reducing the pixel dimensions of liquid crystal microdisplays in search of high resolution has a fundamental impact on their electro-optic behavior. The liquid crystal director orientation becomes distorted due to fringing fields and diffraction effects influence the optical characteristics of the device once the structure features approach the wavelength of the incident light. Three-dimensional finite element simulation of the liquid crystal dynamics with a variable order approach is combined with a full-vector beam propagation analysis to investigate how elasticity and diffraction limit the resolution as a function of the pixel size for transmissive and reflective architectures with vertical liquid crystal alignment. The key liquid crystal properties are considered and the importance of materials with high birefringence is confirmed for small pixel devices as these improve the contrast for a fixed pixel size.

  10. Initial and Final State Interaction Effects in Small-x Quark Distributions

    SciTech Connect

    Xiao, Bo-Wen; Yuan, Feng

    2010-08-30

    We study the initial and final state interaction effects in the transverse momentum dependent parton distributions in the small-x saturation region. In particular, we discuss the quark distributions in the semi-inclusive deep inelastic scattering, Drell-Yan lepton pair production and dijet-correlation processes in pA collisions. We calculate the quark distributions in the scalar-QED model and then extend to the color glass condensate formalism in QCD. The quark distributions are found universal between the DIS and Drell-Yan processes. On the other hand, the quark distribution from the qq'-->qq' channel contribution to the dijet-correlation process is not universal. However, we find that it can be related to the quark distribution in DIS process by a convolution with the normalized unintegrated gluon distribution in the CGC formalism in the large Nc limit.

  11. The Effects of Low-Level Ethanol Blends in 4-Stroke Small Non-Road Engines

    NASA Astrophysics Data System (ADS)

    Reek, Chris

    Small Non-Road Engines (SNRE's) abound in numbers and are used daily by consumers and businesses alike. Considering the atmosphere of change looming in the air regarding alternative fuels, this particular engine classification will also be affected by any change in standardization of fuels. This body of research attempts to address possible ways SNRE's can change their operational characteristics after being fueled by specific yet differing fuels. These characteristics will be contrasted against blends of ethanol with gasoline, from 0% ethanol to 20% ethanol, run on test engines to determine patterns, if any, of these characteristics. Topics include: materials compatibility, engine longevity/durability, engine performance, emissions characteristics, operational temperatures, engine oil characteristics, and inspection of engines. These parameters will be used to compare the effects of low-level blends of ethanol with gasoline has on these particular SNRE's.

  12. Initial and Final State Interaction Effects in Small-x Quark Distributions

    E-print Network

    Bo-Wen Xiao; Feng Yuan

    2010-08-26

    We study the initial and final state interaction effects in the transverse momentum dependent parton distributions in the small-$x$ saturation region. In particular, we discuss the quark distributions in the semi-inclusive deep inelastic scattering, Drell-Yan lepton pair production and dijet-correlation processes in $pA$ collisions. We calculate the quark distributions in the scalar-QED model and then extend to the color glass condensate formalism in QCD. The quark distributions are found universal between the DIS and Drell-Yan processes. On the other hand, the quark distribution from the $qq'\\to qq'$ channel contribution to the dijet-correlation process is not universal. However, we find that it can be related to the quark distribution in DIS process by a convolution with the normalized unintegrated gluon distribution in the color glass condensate formalism in the large $N_c$ limit.

  13. DIRECT BREED EFFECTS ON GROWTH, CARCASS, AND MEAT QUALITY TRAITS OF SHEEP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experiment was conducted to estimate direct breed effects on growth, carcass, and meat quality traits. Rams of nine breeds (Composite, Dorper, Dorset, Finnsheep, Katahdin, Rambouillet, Romanov, Suffolk, and Texel) were mated to Composite ewes. Data recorded on 804 progeny of 130 rams were analy...

  14. 49 CFR 385.819 - Effect of failure to comply with remedial directive.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS SAFETY FITNESS PROCEDURES Remedial Directives § 385.819 Effect of...installation in accordance with § 385.811, does not meet the safety fitness standard set forth in § 385.5(b). With respect to...

  15. 49 CFR 385.819 - Effect of failure to comply with remedial directive.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS SAFETY FITNESS PROCEDURES Remedial Directives § 385.819 Effect of...installation in accordance with § 385.811, does not meet the safety fitness standard set forth in § 385.5(b). With respect to...

  16. Direct and Indirect Effects of Parental Influence upon Adolescent Alcohol Use: A Structural Equation Modeling Analysis

    ERIC Educational Resources Information Center

    Kim, Young-Mi; Neff, James Alan

    2010-01-01

    A model incorporating the direct and indirect effects of parental monitoring on adolescent alcohol use was evaluated by applying structural equation modeling (SEM) techniques to data on 4,765 tenth-graders in the 2001 Monitoring the Future Study. Analyses indicated good fit of hypothesized measurement and structural models. Analyses supported both…

  17. COMMUNITY ECOLOGY -ORIGINAL RESEARCH Direct versus indirect effects of habitat fragmentation

    E-print Network

    With, Kimberly A.

    COMMUNITY ECOLOGY - ORIGINAL RESEARCH Direct versus indirect effects of habitat fragmentation / Accepted: 27 March 2012 / Published online: 12 April 2012 Ó Springer-Verlag 2012 Abstract Habitat area of habitat area and fragmentation on arthropod community patterns in red clover (Trifolium pratense

  18. A bandwidth-optimized WENO scheme for the effective direct numerical simulation of compressible turbulence

    E-print Network

    Martín, Pino

    A bandwidth-optimized WENO scheme for the effective direct numerical simulation of compressible May 2006 Available online 12 July 2006 Abstract Two new formulations of a symmetric WENO method-oscillatory (WENO) schemes provide a means for the DNS of compressible turbulent flow. In WENO schemes [5

  19. The Influence of Depression on the Progression of HIV: Direct and Indirect Effects

    ERIC Educational Resources Information Center

    Schuster, Randi; Bornovalova, Marina; Hunt, Elizabeth

    2012-01-01

    The authors suggest a theoretical model of pathways of HIV progression, with a focus on the contributions of depression--as well as secondary, behavioral and emotional variables. Literature was reviewed regarding (a) comorbid depression and the direct physiological effects on HIV progression and (b) intermediary factors between HIV and disease…

  20. Debris Flows in Direct Dark Matter Searches-The modulation effect

    E-print Network

    J. D. Vergados

    2012-05-17

    The effect of some possible non standard WIMP velocity distributions, like the Debris Flows recently proposed, on the direct dark matter detection rates is investigated. We find that such distributions may be deciphered from the data, especially if the time variation of the event rates due to the annual motion of the Earth is observed

  1. Considerations for Incorporating Bioavailability in Effect-Directed Analysis and Toxicity Identification Evaluation.

    EPA Science Inventory

    In order to avoid a bias toward highly toxic but poorly bioavailable compounds in the effect-directed analysis (EDA) of soils and sediments, approaches are discussed to consider bioavailability in EDA procedures. In parallel, complimentary approaches for making toxicity identific...

  2. Children's Emotional Security and Sleep: Longitudinal Relations and Directions of Effects

    ERIC Educational Resources Information Center

    Keller, Peggy; El-Sheikh, Mona

    2011-01-01

    Background: We examined longitudinal relations between children's sleep and their emotional security in the mother-child, father-child, and parental marital relationships, with the goal of explicating the direction of association over time. Gender-related effects were also examined. Method: Sleep duration was examined through actigraphy, and sleep…

  3. Child- or Adult-Directed Speech and Esteem: Effects on Performance and Arousal in Elderly Adults.

    ERIC Educational Resources Information Center

    Bunce, Vicki L.; Harrison, David W.

    1991-01-01

    Explored effects of speech type and esteem level on performance, physiological arousal level, and subsequent esteem in older adults (n=40). Results indicated that older adults performed difficult tasks better with clarified instructions given in attention-getting manner. Findings were contradictory to more intuitive accounts of child-directed

  4. Direct Effects of Soybean Varietal Selection and Aphis Glycines-Resistant Soybeans on Natural Enemies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The direct effects of three soybean base genetics, each represented by an Aphis glycines-resistant and susceptible variety, on the fitness and performance of two key predators (Orius insidiosus and Harmonia axyridis) were evaluated in the laboratory. Predators were reared from hatch through adulthoo...

  5. DIRECT INJURY, MYIASIS, FORENSICS Effects of Temperature and Tissue Type on the Development of

    E-print Network

    Tomberlin, Jeff

    DIRECT INJURY, MYIASIS, FORENSICS Effects of Temperature and Tissue Type on the Development studies examining the growth of larvae-fed beef liver (Clark et al. 2006). However, it has been. For example, development of L. sericata- fed lung, liver, and heart, from both cows and swine, was compared

  6. Impacts of Direct and Indirect Effects of Anthropogenic Aerosols on Indian Summer Monsoon

    NASA Astrophysics Data System (ADS)

    Wang, Chien; Avramov, Alexander; Lee, Shaoyi

    2014-05-01

    Recent studies have suggested that persistent direct forcing of anthropogenic aerosols, especially absorbing aerosols over Indian subcontinent, can alter the circulation and rainfall pattern besides quantity of Indian summer monsoon. Question also arises on whether the indirect aerosol effects would create an impact opposite to that of direct forcing. To better answer these questions, we have incorporated a multimodal, size and mixing dependent aerosol model (MARC) in the Community Earth System Model (CESM) of NCAR and US DOE. Besides the direct effect, aerosol indirect effects have also been included by coupling the MARC with the two moment Morrison and Gettelman cloud microphysical model in CESM. Several sets of long simulations using CESM with MARC and dynamical ocean GCM driven by interactively predicted aerosol and forcing or by prescribed forcing have been conducted, the pattern and quantity changes caused by both direct and indirect effects of aerosols are identified, the mechanisms behind these impacts are analyzed. Detailed analyses from our study on the aerosol-precipitation causal relations of Indian summer monsoon system will be presented.

  7. Salmonella inhibit T cell proliferation by a direct, contact-dependent immunosuppressive effect

    E-print Network

    Starnbach, Michael

    Salmonella inhibit T cell proliferation by a direct, contact-dependent immunosuppressive effect or activate B and T cells. In this article, we report that DC, when cocultured with Salmonella, fail to Salmonella-infected DC is not simply due to Salmonella- induced programmed DC death or interference with up

  8. The effect of nanoparticle permeation on the bulk rheological properties of mucus from the small intestine.

    PubMed

    Wilcox, M D; Van Rooij, L K; Chater, P I; Pereira de Sousa, I; Pearson, J P

    2015-10-01

    The effectiveness of delivering oral therapeutic peptides, proteins and nucleotides is often hindered by the protective mucus barrier that covers mucosal surfaces of the gastrointestinal (GI) tract. Encapsulation of active pharmaceutical ingredients (API) in nanocarriers is a potential strategy to protect the cargo but they still have to pass the mucus barrier. Decorating nanoparticles with proteolytic enzymes has been shown to increase the permeation through mucus. Here we investigate the effect of poly(acrylic acid) (PAA) nanoparticles decorated with bromelain (BRO), a proteolytic enzyme from pineapple stem, on the bulk rheology of mucus as well as non-decorated poly(lactic-co-glycolic acid) (PLGA) nanoparticles. Porcine intestinal mucus from the small intestine was incubated for 30min in the presence of PLGA nanoparticles or polyacrylic nanoparticles decorated with bromelain (PAA-BRO). The effect of nanoparticles on the rheological properties, weight of gel, released glycoprotein content from mucus as well as the viscosity of liquid removed was assessed. Treatment with nanoparticles decreased mucus gel strength with PAA-BRO reducing it the most. PAA-BRO nanoparticles resulted in the release of increased glycoprotein from the gel network whereas mucus remained a gel and exhibited a similar breakdown stress to control mucus. Therefore it would be possible to use bromelain to increase the permeability of nanoparticles through mucus without destroying the gel and leaving the underlying mucosa unprotected. PMID:25758122

  9. Edge effects in the directionally biased distribution of Choristoneura rosaceana (Lepidoptera: Tortricidae) in apple orchards.

    PubMed

    Hsu, C L; Agnello, A M; Reissig, W H

    2009-04-01

    Edge effect tests have been used in a number of studies on obliquebanded leafroller, Choristoneura rosaceana (Harris), to test for evidence of mated female immigration into pheromone-treated orchards. This type of test compares obliquebanded leafroller presence or activity around the perimeter of an orchard against presence or activity in the interior. Higher numbers detected around the edges of an orchard would indicate higher levels of flight activity at the edge, a pattern that could be generated by high levels of immigration. Recent work has shown that the spatial distribution of recaptured obliquebanded leafroller adults released from a single location can be directionally biased, which could obscure the ability to detect an edge effect. To test this theory, data from an orchard study conducted in 1991 that found no significant edge effect was reanalyzed. When we accounted for the directional bias in the distribution of first-generation mated female moths, we found an edge effect with significantly more mated females captured in the edge traps than in the center or mid-interior traps. No edge effect was found when the directional bias was ignored. In addition, second-generation males and mated females both showed a significant edge effect that had not been detected in the original analysis, which had combined both first- and second-generation data. PMID:19389293

  10. Jamming effect analysis of infrared reticle seeker for directed infrared countermeasures

    NASA Astrophysics Data System (ADS)

    Bae, Tae-Wuk; Kim, Byoung-Ik; Kim, Young-Choon; Ahn, Sang-Ho

    2012-09-01

    In directed infrared countermeasures (DIRCM), the purpose of jamming toward missiles is making missiles miss the target (aircraft of our forces) in the field of view. Since the DIRCM system directly emits the pulsing flashes of infrared (IR) energy to missiles, it is more effective than present flare method emitting IR source to omni-direction. In this paper, we implemented a reticle seeker simulation tool using MATLAB-SIMULINK, in order to analyze jamming effect of spin-scan and con-scan reticle missile seeker used widely in the world, though it was developed early. Because the jammer signal has influence on the missile guidance system using its variable frequency, it is very important technique among military defense systems protecting our forces from missiles of enemy. Simulation results show that jamming effect is greatly influenced according to frequency, phase and intensity of jammer signal. Especially, jammer frequency has the largest influence on jamming effect. Through our reticle seeker simulation tool, we can confirm that jamming effect toward missiles is significantly increased when jammer frequency is similar to reticle frequency. Finally, we evaluated jamming effect according to jammer frequencies, by using correlation coefficient as an evaluation criterion of jamming performance in two reticle missile seekers.

  11. Neuroprotective Effect of Erythropoietin against Pressure Ulcer in a Mouse Model of Small Fiber Neuropathy

    PubMed Central

    Danigo, Aurore; Magy, Laurent; Richard, Laurence; Desmoulière, Alexis; Bourthoumieu, Sylvie; Funalot, Benoît; Demiot, Claire

    2014-01-01

    An increased risk of skin pressure ulcers (PUs) is common in patients with sensory neuropathies, including those caused by diabetes mellitus. Recombinant human erythropoietin (rhEPO) has been shown to protect the skin against PUs developed in animal models of long-term diabetes. The aim of this work was to determine whether rhEPO could prevent PU formation in a mouse model of drug-inducedSFN. Functional SFN was induced by systemic injection of resiniferatoxin (RTX, 50 µg/kg, i.p.). RhEPO (3000 UI/kg, i.p.) was given the day before RTX injection and then every other day. Seven days after RTX administration, PUs were induced by applying two magnetic plates on the dorsal skin. RTX-treated mice expressed thermal and mechanical hypoalgesia and showed calcitonin gene-related peptide (CGRP) and substance P (SP) depletion without nerve degeneration or vascular dysfunction. RTX mice developed significantly larger stage 2 PUs than Vehicle mice. RhEPO prevented thermal and mechanical hypoalgesia and neuropeptide depletion in small nerve fibers. RhEPO increased hematocrit and altered endothelium-dependent vasodilatation without any effect on PU formation in Vehicle mice. The characteristics of PUs in RTX mice treated with rhEPO and Vehicle mice were found similar. In conclusion, RTX appeared to increased PU development through depletion of CGRP and SP in small nerve fibers, whereas systemic rhEPO treatment had beneficial effect on peptidergic nerve fibers and restored skin protective capacities against ischemic pressure. Our findings support the evaluation of rhEPO and/or its non-hematopoietic analogs in preventing to prevent PUs in patients with SFN. PMID:25422898

  12. Neuroprotective effect of erythropoietin against pressure ulcer in a mouse model of small fiber neuropathy.

    PubMed

    Danigo, Aurore; Magy, Laurent; Richard, Laurence; Desmoulière, Alexis; Bourthoumieu, Sylvie; Funalot, Benoît; Demiot, Claire

    2014-01-01

    An increased risk of skin pressure ulcers (PUs) is common in patients with sensory neuropathies, including those caused by diabetes mellitus. Recombinant human erythropoietin (rhEPO) has been shown to protect the skin against PUs developed in animal models of long-term diabetes. The aim of this work was to determine whether rhEPO could prevent PU formation in a mouse model of drug-induced SFN. Functional SFN was induced by systemic injection of resiniferatoxin (RTX, 50 µg/kg, i.p.). RhEPO (3000 UI/kg, i.p.) was given the day before RTX injection and then every other day. Seven days after RTX administration, PUs were induced by applying two magnetic plates on the dorsal skin. RTX-treated mice expressed thermal and mechanical hypoalgesia and showed calcitonin gene-related peptide (CGRP) and substance P (SP) depletion without nerve degeneration or vascular dysfunction. RTX mice developed significantly larger stage 2 PUs than Vehicle mice. RhEPO prevented thermal and mechanical hypoalgesia and neuropeptide depletion in small nerve fibers. RhEPO increased hematocrit and altered endothelium-dependent vasodilatation without any effect on PU formation in Vehicle mice. The characteristics of PUs in RTX mice treated with rhEPO and Vehicle mice were found similar. In conclusion, RTX appeared to increased PU development through depletion of CGRP and SP in small nerve fibers, whereas systemic rhEPO treatment had beneficial effect on peptidergic nerve fibers and restored skin protective capacities against ischemic pressure. Our findings support the evaluation of rhEPO and/or its non-hematopoietic analogs in preventing to prevent PUs in patients with SFN. PMID:25422898

  13. Effects of small variations of speed of sound in optoacoustic tomographic imaging

    SciTech Connect

    Deán-Ben, X. Luís; Ntziachristos, Vasilis; Razansky, Daniel

    2014-07-15

    Purpose: Speed of sound difference in the imaged object and surrounding coupling medium may reduce the resolution and overall quality of optoacoustic tomographic reconstructions obtained by assuming a uniform acoustic medium. In this work, the authors investigate the effects of acoustic heterogeneities and discuss potential benefits of accounting for those during the reconstruction procedure. Methods: The time shift of optoacoustic signals in an acoustically heterogeneous medium is studied theoretically by comparing different continuous and discrete wave propagation models. A modification of filtered back-projection reconstruction is subsequently implemented by considering a straight acoustic rays model for ultrasound propagation. The results obtained with this reconstruction procedure are compared numerically and experimentally to those obtained assuming a heuristically fitted uniform speed of sound in both full-view and limited-view optoacoustic tomography scenarios. Results: The theoretical analysis showcases that the errors in the time-of-flight of the signals predicted by considering the straight acoustic rays model tend to be generally small. When using this model for reconstructing simulated data, the resulting images accurately represent the theoretical ones. On the other hand, significant deviations in the location of the absorbing structures are found when using a uniform speed of sound assumption. The experimental results obtained with tissue-mimicking phantoms and a mouse postmortem are found to be consistent with the numerical simulations. Conclusions: Accurate analysis of effects of small speed of sound variations demonstrates that accounting for differences in the speed of sound allows improving optoacoustic reconstruction results in realistic imaging scenarios involving acoustic heterogeneities in tissues and surrounding media.

  14. Inhibitory effect of Disulfiram/copper complex on non-small cell lung cancer cells

    SciTech Connect

    Duan, Lincan; Shen, Hongmei; Zhao, Guangqiang; Yang, Runxiang; Cai, Xinyi; Zhang, Lijuan; Jin, Congguo; Huang, Yunchao

    2014-04-18

    Highlights: • Disulfiram and copper synergistically inhibit lung cancer cell proliferation. • Lung cancer cell colony formation ability is inhibited by Disulfiram/copper. • Disulfiram/copper increases the sensitivity of cisplatin to lung cancer cells. • Lung cancer stem cells are specifically targeted by Disulfiram/copper complex. - Abstract: Non-small cell lung cancer (NSCLC) is the most common cause of cancer-related death in both men and women worldwide. Recently, Disulfiram has been reported to be able to inhibit glioblastoma, prostate, or breast cancer cell proliferation. In this study, the synergistic effect of Disulfiram and copper on NSCLC cell growth was investigated. Inhibition of cancer cell proliferation was detected by 1-(4,5-Dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT) assay and cell cycle analysis. Liquid colony formation and tumor spheroid formation assays were used to evaluate their effect on cancer cell clonogenicity. Real-time PCR was performed to test the mRNA level of cancer stem cell related genes. We found that Disulfiram or copper alone did not potently inhibit NSCLC cell proliferation in vitro. However, the presence of copper significantly enhanced inhibitory effect of Disulfiram on NSCLC cell growth, indicating a synergistic effect between Disulfiram and copper. Cell cycle analysis showed that Disulfiram/copper complex caused NSCLC cell cycle arrest in G2/M phase. Furthermore, Disulfiram/copper significantly increased the sensitivity of cisplatin in NSCLC cells tested by MTT assay. Liquid colony formation assay revealed that copper dramatically increased the inhibitory effect of Disulfiram on NSCLC cell colony forming ability. Disulfiram combined with copper significantly attenuated NSCLC cell spheroid formation and recuded the mRNA expression of lung cancer stem cell related genes. Our data suggest that Disulfiram/copper complex alone or combined with other chemotherapy is a potential therapeutic strategy for NSCLC patients.

  15. Effect of bowel rehabilitative therapy on structural adaptation of remnant small intestine: animal experiment

    PubMed Central

    Zhou, Xin; Li, Yuan Xin; Li, Ning; Li, Jie Shou

    2001-01-01

    AIM: To investigate the individual and the combined effects of glutamine, dietary fiber, and growth hormone on the structural adaptation of the remnant small bowel. METHODS: Forty-two adult male Sprague-Dawley rats underwent 85% mid-small bowel resection and received total parenteral nutrition (TPN) support during the first three postoperational days. From the 4th postoperational day, animals were randomly assigned to receive 7 different treatments for 8 d: TPNcon group, receiving TPN and enteral 20 g·L-1 glycine perfusion; TPN + Gln group, receiving TPN and enteral 20 g·L-1 glutamine perfusion; ENcon group, receiving enteral nutrition (EN) fortified with 20 g·L-1 glycine; EN + Gln group, enteral nutrition fortified with 20 g·L-1 glutamine; EN + Fib group, enteral nutrition and 2 g·L-1 oral soybean fiber; EN + GH group, enteral nutrition and subcutaneous growth hormone (GH) (0.3IU) injection twice daily; and ENint group, glutamine-enriched EN, oral soybean fiber, and subcutaneous GH injection. RESULTS: Enteral glutamine perfusion during TPN increased the small intestinal villus height (jejunal villus height 250 µm ± 29 µm in TPNcon vs 330 µm ± 54 µm in TPN + Gln, ileal villus height 260 µm ± 28 µm in TPNcon vs 330 µm ± 22 µm in TPN + Gln, P < 0.05) and mucosa thickness (jejunal mucosa thickness 360 µm ± 32 µm in TPNcon vs 460 µm ± 65 µm in TPN +Gln, ileal mucosa thickness 400 µm ± 25 µm in TPNcon vs 490 µm ± 11 µm in TPN + Gln, P < 0.05) in comparison with the TPNcon group. Either fiber supplementation or GH administration improved body mass gain (end body weight 270 g ± 3.6 g in EN + Fib, 265.7 g ± 3.3 g in EN + GH, vs 257 g ± 3.3 g in ENcon, P < 0.05), elevated plasma insulin-like growth factor (IGF-I) level (880 µg·L-1 ± 52 µg·L-1 in EN + Fib, 1200 µg·L-1 ± 96 µg·L-1 in EN ± GH, vs 620 µg·L-1 ± 43 µg·L-1 in ENcon, P < 0.05), and increased the villus height (jejunum 560 µm ± 44 µm in EN ± Fib, 530 µm ± 30 µm in EN ± GH, vs 450 µm ± 44 µm in ENcon, ileum 400 µm ± 30 µm in EN + Fib, 380 µm ± 49 µm in EN ± GH, vs 320 µm ± 16 µm in ENcon, P < 0.05) and the mucosa thickness (jejunum 740 µm ± 66 µm in EN ± Fib, 705 µm ± 27 µm in ENGH, vs 608 µm ± 58 µm in ENcon, ileum 570 µm ± 27 µm in EN ± Fib, 560 µm ± 56 µm in EN ± GH, vs 480 µm ± 40 µm in ENcon, P < 0.05) in remnant jejunum and ileum. Glutamine-enriched EN produced little effect in body mass, plasma IGF-I level, and remnant small bowel mucosal structure. The ENint group had greater body mass (280 g ± 2.2 g), plasma IGF-I level (1450 µg·L-1 ± 137 µg·L-1), and villus height (jejunum 620 µm ± 56 µm, ileum 450 µm ± 31 µm) and mucosal thickness (jejunum 800 µm ± 52 µm, ileum 633 µm ± 33 µm) than those in ENcon, EN + Gln (jejunum villus height and mucosa thickness 450 µm ± 47 µm and 610 µm ± 63 µm, ileum villus height and mucosa thickness 330 µm ± 39 µm and 500 µm ± 52 µm), EN + GH groups (P < 0.05), and than those in EN + Fib group although no statistical significance was attained. CONCLUSION: Both dietary fiber and GH when used separately can enhance the postresectional small bowel structural adaptation. Simultaneous use of these two gut-trophic factors can produce synergistic effects on small bowel structural adaptation. Enteral glutamine perfusion is beneficial in preserving small bowel mucosal structure during TPN, but has little beneficial effect during EN. PMID:11819735

  16. Stochastic earthquake source model: the omega-square hypothesis and the directivity effect

    NASA Astrophysics Data System (ADS)

    Molchan, G.

    2015-07-01

    Recently A. Gusev suggested and numerically investigated the doubly stochastic earthquake source model. The model is supposed to demonstrate the following features in the far-field body waves: (1) the omega-square high-frequency (HF) behaviour of displacement spectra; (2) lack of the directivity effect in HF radiation; and (3) a stochastic nature of the HF signal component. The model involves two stochastic elements: the local stress drop (SD) on a fault and the rupture time function (RT) with a linear dominant component. The goal of the present study is to investigate the Gusev model theoretically and to find conditions for (1, 2) to be valid and stable relative to receiver site. The models with smooth elements SD, RT are insufficient for these purposes. Therefore, SD and RT are treated as realizations of stochastic fields of the fractal type. The local smoothness of such fields is characterized by the fractional (Hurst) exponent H, 0 < H < 1. This allows us to consider a wide class of stochastic functions without regard to their global spectral properties. We show that the omega-square behavior of the model is achieved approximately if the rupture time function is almost regular (H˜1) while the stress drop is rough function of any index H. However, if the rupture front is linear, the local stress drop has to be function of minimal smoothness (H˜0). The situation with the directivity effect is more complicated: for different RT models with the same fractal index, the effect may or may not occur. The nature of the phenomenon is purely analytical. The main controlling factor for the directivity is the degree of smoothness of the 2-D distributions of RT random function. For this reason the directivity effect is unstable. This means that in practice the opposite conclusions relative to the statistical significance of the directivity effect are possible.

  17. Survival after total body irradiation: Effects of irradiation of exteriorized small intestine. (Reannouncement with new availability information)

    SciTech Connect

    Vriesendorp, H.M.; Vigneulle, R.M.; Kitto, G.; Pelky, T.; Taylor, P.

    1993-12-31

    Rats receiving lethal irradiation to their exteriorized small intestine with pulsed 18 MVp bremsstrahlung radiation live about 4 days longer than rats receiving a dose of total-body irradiation (TBI) causing intestinal death. The LD50 for intestinal irradiation is approximately 6 Gy higher than the LD50 for intestinal death after TBI. Survival time after exteriorized intestinal irradiation can be decreased, by adding abdominal irradiation. Adding thoracic or pelvic irradiation does not alter survival time. Shielding of large intestine improves survival after irradiation of the rest of the abdomen while the small intestine is also shielded. The kinetics of histological changes in small intestinal tissues implicate the release of humoral factors after irradiation of the abdomen. Radiation injury develops faster in the first (proximal) 40 cm of the small intestine and is expressed predominantly as shortening in villus height. In the last (distal) 40 cm of the small intestine, the most pronounced radiation effect is a decrease in the number of crypts per millimeter. Irradiation (20 Gy) of the proximal small intestine causes 92 % mortality (median survival 10 days). Irradiation (20 Gy) of the distal small intestine causes 27% mortality (median survival > 30 days). In addition to depletion of crypt stem cells in the small intestine, other issues (humoral factors, irradiated subsection of the small intestine and shielding of the large intestine) appear to influence radiation-induced intestinal mortality.

  18. Invited commentary: boundless science--putting natural direct and indirect effects in a clearer empirical context.

    PubMed

    Naimi, Ashley I

    2015-07-15

    Epidemiologists are increasingly using natural effects for applied mediation analyses, yet 1 key identifying assumption is unintuitive and subject to some controversy. In this issue of the Journal, Jiang and VanderWeele (Am J Epidemiol. 2015;182(2):105-108) formalize the conditions under which the difference method can be used to estimate natural indirect effects. In this commentary, I discuss implications of the controversial "cross-worlds" independence assumption needed to identify natural effects. I argue that with a binary mediator, a simple modification of the authors' approach will provide bounds for natural direct and indirect effect estimates that better reflect the capacity of the available data to support empirical statements on the presence of mediated effects. I discuss complications encountered when odds ratios are used to decompose effects, as well as the implications of incorrectly assuming the absence of exposure-induced mediator-outcome confounders. I note that the former problem can be entirely resolved using collapsible measures of effect, such as risk ratios. In the Appendix, I use previous derivations for natural direct effect bounds on the risk difference scale to provide bounds on the odds ratio scale that accommodate 1) uncertainty due to the cross-world independence assumption and 2) uncertainty due to the cross-world independence assumption and the presence of exposure-induced mediator-outcome confounders. PMID:25944884

  19. New Modeling Approaches to Study DNA Damage by the Direct and Indirect Effects of Ionizing Radiation

    NASA Technical Reports Server (NTRS)

    Plante, Ianik; Cucinotta, Francis A.

    2012-01-01

    DNA is damaged both by the direct and indirect effects of radiation. In the direct effect, the DNA itself is ionized, whereas the indirect effect involves the radiolysis of the water molecules surrounding the DNA and the subsequent reaction of the DNA with radical products. While this problem has been studied for many years, many unknowns still exist. To study this problem, we have developed the computer code RITRACKS [1], which simulates the radiation track structure for heavy ions and electrons, calculating all energy deposition events and the coordinates of all species produced by the water radiolysis. In this work, we plan to simulate DNA damage by using the crystal structure of a nucleosome and calculations performed by RITRACKS. The energy deposition events are used to calculate the dose deposited in nanovolumes [2] and therefore can be used to simulate the direct effect of the radiation. Using the positions of the radiolytic species with a radiation chemistry code [3] it will be possible to simulate DNA damage by indirect effect. The simulation results can be compared with results from previous calculations such as the frequencies of simple and complex strand breaks [4] and with newer experimental data using surrogate markers of DNA double ]strand breaks such as . ]H2AX foci [5].

  20. Effects of Space Environment on Flow and Concentration During Directional Solidification

    NASA Technical Reports Server (NTRS)

    Benjapiyaporn, C.; Timchenko, V.; Leonardi, E.; deVahlDavis, G.; 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 numerically investigate the effects of g-jitter on directional solidification. A background gravity of 1 micro-g has been assumed, and new results for the effects of periodic disturbances over a range of amplitudes and frequencies on solute field and segregation have been presented.

  1. A breakdown in communication? Understanding the effects of aging on the human small intestine epithelium

    PubMed Central

    2015-01-01

    In the intestine, a single layer of epithelial cells sealed together at their apical surfaces by tight junctions helps to prevent the luminal commensal and pathogenic micro-organisms and their toxins from entering host tissues. The intestinal epithelium also helps to maintain homoeostasis in the mucosal immune system by expressing anti-inflammatory cytokines in the steady state and inflammatory cytokines in response to pathogens. Although the function of the mucosal immune system is impaired in elderly humans, the molecular mechanisms which cause this dramatic functional decline are poorly understood. Our current understanding of the effects of aging on the physical and immunological properties of the intestinal epithelial barrier is also very limited. In this issue of Clinical Science, Man et al. provide further insight into the effects of aging on small intestinal barrier function in humans and the influence that gut luminal micro-organisms may have on it. Using human terminal ileal biopsy tissues they show that intestinal permeability to solutes, but not macromolecules, was significantly increased in the intestines of elderly humans. This was accompanied by elevated expression of the pro-inflammatory cytokine interleukin (IL)-6 which appeared to modulate claudin-2 expression and solute permeability in the epithelium. Conversely, IL-8 synthesis in response to flagellin stimulation was reduced in intestines of the elderly subjects, but was not associated with effects on Toll-like receptor 5 (TLR5) expression. These data provide an important advance in our understanding on the effects of aging on intestinal permeability and innate mucosal immune responsiveness in elderly humans. PMID:26186738

  2. Antiproliferative effect of Toona sinensis leaf extract on non-small-cell lung cancer.

    PubMed

    Yang, Chih-Jen; Huang, Yu-Jung; Wang, Cheng-Yuan; Wang, Pei-Hui; Hsu, Hseng-Kuang; Tsai, May-Jywan; Chen, Yu-Chu; Bharath Kumar, V; Huang, Ming-Shyan; Weng, Ching-Feng

    2010-06-01

    Toona sinensis (TS), which is also known as Cedrela sinensis, belongs to Meliaceae family, the compounds identified from this TS leaves possess a wide range of biologic functions, such as hypoglycemic effects, anti-LDL glycative activity, antioxidant activities, and inhibition of sudden acute respiratory syndrome (SARS) coronavirus replication. However, their effect against cancer cells is not well explored. In this study, to understand the cytotoxic effect and molecular mechanism stimulated by TSL-1 (TS leaf extract fraction) we employed three different non-small-cell lung cancer (NSCLC) cell lines: H441 cells (lung adenocarcinoma), H661 cells (lung large cell carcinoma) and H520 cells (lung squamous cell carcinoma). IC50 value was varied between these three cell lines, the least IC(50) value was observed in TSL-1-treated H661cells. Exposure of NSCLC cells to TSL-1 caused cell-cycle arrest in subG1 phase and caused apoptosis. Moreover, TSL-1 treatment decreased the cell-cycle regulators; cyclin D1 and CDK4 proteins by up regulating p27 expression in a dose-dependent manner. Thus, the TSL-1-induced apoptosis was further confirmed by cell morphology, subG1 peak accumulation, poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) cleavage, propidium iodide (PI)-Annexin-V double staining, and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. The decreased Bcl2 protein level was concurrent with an increased Bax protein level in all 3 cell lines. Additionally, the tumoricidal effect of TSL-1 was measured using a xenograft model, after 5 weeks of TSL-1 treatment by various regimen caused regression of tumor. Taken together both these in vitro and in vivo studies revealed that TSL-1 is a potent inhibitor against NSCLC growth and our provoking result suggest that TSL-1 can be a better nutriceutical as a singlet or along with doublet agents (taxane, vinorelbine, and gemcitabine) for treating NSCLC. PMID:20478545

  3. A breakdown in communication? Understanding the effects of aging on the human small intestine epithelium.

    PubMed

    Mabbott, Neil A

    2015-10-01

    In the intestine, a single layer of epithelial cells sealed together at their apical surfaces by tight junctions helps to prevent the luminal commensal and pathogenic micro-organisms and their toxins from entering host tissues. The intestinal epithelium also helps to maintain homoeostasis in the mucosal immune system by expressing anti-inflammatory cytokines in the steady state and inflammatory cytokines in response to pathogens. Although the function of the mucosal immune system is impaired in elderly humans, the molecular mechanisms which cause this dramatic functional decline are poorly understood. Our current understanding of the effects of aging on the physical and immunological properties of the intestinal epithelial barrier is also very limited. In this issue of Clinical Science, Man et al. provide further insight into the effects of aging on small intestinal barrier function in humans and the influence that gut luminal micro-organisms may have on it. Using human terminal ileal biopsy tissues they show that intestinal permeability to solutes, but not macromolecules, was significantly increased in the intestines of elderly humans. This was accompanied by elevated expression of the pro-inflammatory cytokine interleukin (IL)-6 which appeared to modulate claudin-2 expression and solute permeability in the epithelium. Conversely, IL-8 synthesis in response to flagellin stimulation was reduced in intestines of the elderly subjects, but was not associated with effects on Toll-like receptor 5 (TLR5) expression. These data provide an important advance in our understanding on the effects of aging on intestinal permeability and innate mucosal immune responsiveness in elderly humans. PMID:26186738

  4. 76 FR 26948 - Small Business Jobs Act Tour: Selected Provisions Having an Effect on Government Contracting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ...No. SBA-2011-006] Small Business Jobs Act Tour: Selected Provisions Having an...implementation of provisions of the Small Business Jobs Act of 2010 (SBJA). This document corrects...CONTACT: Richard L. Miller, Small Business Job's Act Tour-Office of Government...

  5. 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

    ...No. SBA-2011-0006] Small Business Jobs Act Tour: Selected Provisions Having an...several provisions of the Small Business Jobs Act of 2010 (SBJA). On Monday, March...submitting comments. Mail: Small Business Jobs Act Tour--Office of Government...

  6. ANALYSIS OF THE PERFORMANCE AND COST EFFECTIVENESS OF NINE SMALL WIND ENERGY CONVERSION SYSTEMS FUNDED BY THE DOE SMALL GRANTS PROGRAM

    SciTech Connect

    Kay, J.

    1982-04-01

    This report presents an analysis of the technical performance and cost effectiveness of nine small wind energy conversion systems (SWECS) funded during FY 1979 by the U.S. Department of Energy. Chapter 1 gives an analytic framework with which to evaluate the systems. Chapter 2 consists of a review of each of the nine projects, including project technical overviews, estimates of energy savings, and results of economic analysis. Chapter 3 summarizes technical, economic, and institutional barriers that are likely to inhibit widespread dissemination of SWECS technology.

  7. Determination of the Hubble Space Telescope effective conic-constant error from direct image measurements.

    PubMed

    Meinel, A B; Meinel, M P; Schulte, D H

    1993-04-01

    Direct measurement of discernible features in the Hubble Space Telescope (HST) imagery has enabled a self-consistent determination to be made of the effective conic constant of HST images taken with planetary camera 6 (PC-6) of the wide field and planetary camera. Before being corrected for the contribution from PC-6, the conic constant is - 1.01429 +/- 0.0002. The correction for PC-6 is less accurately determined but probably lies between -0.0002 and 0.0004. As a result the HST optics are characterized best by a conic constant of - 1.0140 +/- 0.0003 as obtained from direct image measurements. PMID:20820304

  8. Determination of the Hubble Space Telescope effective conic-constant error from direct image measurements

    NASA Technical Reports Server (NTRS)

    Meinel, Aden B.; Meinel, Marjorie P.; Schulte, Daniel H.

    1993-01-01

    Direct measurement of discernible features in the Hubble Space Telescope (HST) imagery has enabled a self-consistent determination to be made of the effective conic constant of HST images taken with planetary camera 6 (PC-6) of the wide field and planetary camera. Before being corrected for the contribution from PC-6, the conic constant is -1.01429 +/- 0.0002. The correction for PC-6 is less accurately determined but probably lies between -0.0002 and 0.0004. As a result the HST optics are characterized best by a conic constant of -1.0140 +/-0.0003 as obtained from direct image measurements.

  9. Effects of Constant and Variable Accelerations on Crystals Grown onboard Spacecraft by the Method of Directional Crystallization

    NASA Astrophysics Data System (ADS)

    Feonychev, A. I.; Dolgikh, G. A.

    2001-07-01

    The effect of constant and time-dependent accelerations (vibrations) on the melt flow and heat and mass transfer in the process of crystal growth by the method of directional crystallization (Bridgman method) onboard spacecraft is numerically investigated. The mathematical formulation of the problem and the technique to solve it numerically are given. The time-averaged flow arising under the action of vibrations in a nonisothermal fluid is investigated. With the help of a rational choice of dimensionless similitude parameters, a generalized dependence on the intensity of melt flow is obtained for the radial segregation of dopants. This dependence is invariant with respect to the type of motive power and thermal boundary conditions in the region of very small velocities of melt flow (“creeping” flow), which are characteristic for microgravity conditions. The allowable levels of constant accelerations, as well as the frequency dependences of tolerable vibrations, are obtained for five typical semiconductor materials: Ge(Ga), GaAs(Te), InSb(Te), Si(P), and Si(B). It is shown that the radial segregation of dopant is much more sensitive to microaccelerations than the axial one. In the region of small velocities, the latter is determined by the duration of the transition regime, which depends on certain physical properties of the melt. New problems that resulted from the investigations performed are discussed.

  10. Rupture Directivity Effect on the Probabilistic Seismic Hazard Maps in the Marmara Region, Turkey

    NASA Astrophysics Data System (ADS)

    Spagnuolo, E.; Akinci, A.; Herrero, A.; Pucci, S.

    2014-12-01

    In this study, we attempt to incorporate the rupture directivity effects into seismic hazard analysis in the Marmara region, Turkey. We introduce information about the fault segments by focusing on the fault rupture characteristics, near source directivity effects and its influence on the probabilistic seismic hazard analyses (PSHA) accounting for the azimuthal variations of the ground motion spatial distribution. An analytical model developed by Spudich and Chiou (2008) is used as a corrective factor that modifies four ground motion predictive equations (GMPEs) (Abrahamson & Silva 2008; Boore & Atkinson 2008; Campbell & Bozorgnia 2008; Chiou &Youngs 2008) and accounts for rupture related parameters that generally lump together into the term directivity effect. In this paper, we only use the relation calibrated for the Abrahamson & Silva (2008) and Boore & Atkinson (2008). In order to evaluate the impact of the rupture directivity effects to ground motion hazard in the near source we attempt to calculate the fault-based probabilistic seismic hazard maps (PSHA) of mean Peak Ground Acceleration (PGA) having 10% probability of exceedance in 50 years on rock site condition. Therefore the PSHMs for the Marmara region is produced incorporating detailed knowledge of active faulting and tectonic rates in earthquake recurrence models using the available database and the most innovative approaches. In order to test the impact of the corrective factor on seismic hazard we first considered its effect on a normal fault and on a strike slip fault as a function of magnitude. Seismic hazard is given in terms of Spectral Acceleration (SA) at seven different periods. We also report the percentage ratio between the seismic hazards computed with the directivity model and without it, over the seismic hazard resulting from the standard practice. Finally, we improve the seismic hazard maps in the near fault source incorporating the directivity effects in the ground motion prediction in the Marmara Region. The correction is applied to compute spectral accelerations at 2 sec, 3 sec and 5 sec. At 5 sec the increment in seismic hazard estimation is up to 50% and is achieved along the entire system of faults. At 2 sec the effectiveness of the corrective factor is lower (up to 30%). The areas affected by the modifications are approximately the same.

  11. Small molecules make big differences: molecular doping effects on electronic and optical properties of phosphorene.

    PubMed

    Jing, Yu; Tang, Qing; He, Peng; Zhou, Zhen; Shen, Panwen

    2015-03-01

    Systematical computations on the density functional theory were performed to investigate the adsorption of three typical organic molecules, tetracyanoquinodimethane (TCNQ), tetracyanoethylene (TCNE) and tetrathiafulvalene (TTF), on the surface of phosphorene monolayers and thicker layers. There exist considerable charge transfer and strong non-covalent interaction between these molecules and phosphorene. In particular, the band gap of phosphorene decreases dramatically due to the molecular modification and can be further tuned by applying an external electric field. Meanwhile, surface molecular modification has proven to be an effective way to enhance the light harvesting of phosphorene in different directions. Our results predict a flexible method toward modulating the electronic and optical properties of phosphorene and shed light on its experimental applications. PMID:25665596

  12. Small molecules make big differences: molecular doping effects on electronic and optical properties of phosphorene

    NASA Astrophysics Data System (ADS)

    Jing, Yu; Tang, Qing; He, Peng; Zhou, Zhen; Shen, Panwen

    2015-03-01

    Systematical computations on the density functional theory were performed to investigate the adsorption of three typical organic molecules, tetracyanoquinodimethane (TCNQ), tetracyanoethylene (TCNE) and tetrathiafulvalene (TTF), on the surface of phosphorene monolayers and thicker layers. There exist considerable charge transfer and strong non-covalent interaction between these molecules and phosphorene. In particular, the band gap of phosphorene decreases dramatically due to the molecular modification and can be further tuned by applying an external electric field. Meanwhile, surface molecular modification has proven to be an effective way to enhance the light harvesting of phosphorene in different directions. Our results predict a flexible method toward modulating the electronic and optical properties of phosphorene and shed light on its experimental applications.

  13. Novel small-molecule AMPK activator orally exerts beneficial effects on diabetic db/db mice.

    PubMed

    Li, Yuan-Yuan; Yu, Li-Fang; Zhang, Li-Na; Qiu, Bei-Ying; Su, Ming-Bo; Wu, Fang; Chen, Da-Kai; Pang, Tao; Gu, Min; Zhang, Wei; Ma, Wei-Ping; Jiang, Hao-Wen; Li, Jing-Ya; Nan, Fa-Jun; Li, Jia

    2013-12-01

    AMP-activated protein kinase (AMPK), which is a pivotal guardian of whole-body energy metabolism, has become an attractive therapeutic target for metabolic syndrome. Previously, using a homogeneous scintillation proximity assay, we identified the small-molecule AMPK activator C24 from an optimization based on the original allosteric activator PT1. In this paper, the AMPK activation mechanism of C24 and its potential beneficial effects on glucose and lipid metabolism on db/db mice were investigated. C24 allosterically stimulated inactive AMPK ? subunit truncations and activated AMPK heterotrimers by antagonizing autoinhibition. In primary hepatocytes, C24 increased the phosphorylation of AMPK downstream target acetyl-CoA carboxylase dose-dependently without changing intracellular AMP/ATP ratio, indicating its allosteric activation in cells. Through activating AMPK, C24 decreased glucose output by down-regulating mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in primary hepatocytes. C24 also decreased the triglyceride and cholesterol contents in HepG2 cells. Due to its improved bioavailability, chronic oral treatment with multiple doses of C24 significantly reduced blood glucose and lipid levels in plasma, and improved the glucose tolerance of diabetic db/db mice. The hepatic transcriptional levels of PEPCK and G6Pase were reduced. These results demonstrate that this orally effective activator of AMPK represents a novel approach to the treatment of metabolic syndrome. PMID:24055643

  14. The effects of hindlimb unweighting on the capacitance of rat small mesenteric veins

    NASA Technical Reports Server (NTRS)

    Dunbar, S. L.; Berkowitz, D. E.; Brooks-Asplund, E. M.; Shoukas, A. A.

    2000-01-01

    Microgravity is associated with an impaired cardiac output response to orthostatic stress. Mesenteric veins are critical in modulating cardiac filling through venoconstriction. The purpose of this study was to determine the effects of simulated microgravity on the capacitance of rat mesenteric small veins. We constructed pressure-diameter relationships from vessels of 21-day hindlimb-unweighted (HLU) rats and control rats by changing the internal pressure and measuring the external diameter. Pressure-diameter relationships were obtained both before and after stimulation with norepinephrine (NE). The pressure-diameter curves of HLU vessels were shifted to larger diameters than control vessels. NE (10(-4) M) constricted veins from control animals such that the pressure-diameter relationship was significantly shifted downward (i.e., to smaller diameters at equal pressure). NE had no effect on vessels from HLU animals. These results indicate that, after HLU, unstressed vascular volume may be increased and can no longer decrease in response to sympathetic stimulation. This may partially underlie the mechanism leading to the exaggerated fall in cardiac output and stroke volume seen in astronauts during an orthostatic stress after exposure to microgravity.

  15. Trapezoidal-shaped detector to reduce edge effects in small gamma camera

    NASA Astrophysics Data System (ADS)

    Chung, Yong Hyun; Hwang, Ji Yeon; Baek, Cheol-Ha; An, Su Jung; Kim, Hyun-Il; Kim, Kwang Hyun

    2011-08-01

    In recent years, there has been a growing interest in compact and high resolution small gamma cameras for the early detection of breast cancer and thyroid diseases. We proposed a new detector consisting of a trapezoidal-shaped crystal and a position-sensitive photomultiplier tube (PSPMT) to reduce the edge effect. In this study, the imaging performance of the proposed detector was evaluated by DETECT2000 simulation. Trapezoidal-shaped NaI(Tl) and CsI(Tl) crystals were modeled and the 2-dimensional event positions were calculated using Anger-logic. 99mTc (140 keV) and 131I (364 keV) gamma rays were generated on evenly spaced points with 3.0 mm spacing in the X-Y plane starting 1.0 mm away from the corner surface and 10,000 gamma events were simulated at each location. The simulated results demonstrated that all the 99mTc and 131I point sources were clearly identified in the NaI(Tl) crystal. CsI(Tl) crystal could image 131I sources without edge effect but did not distinguish 99mTc points at the periphery region due to low light yield. In conclusion, our new detector with an enlarged FOV without increasing crystal size could be a useful tool in breast as well as thyroid imaging.

  16. Parrotfish size as a useful indicator of fishing effects in a small Caribbean island

    NASA Astrophysics Data System (ADS)

    Vallès, Henri; Gill, David; Oxenford, Hazel A.

    2015-09-01

    There is an urgent need to develop simple indicators of fishing effects for the implementation of ecosystem-based fisheries management in the Caribbean. In this study, we compare the ability of three simple metrics (average individual fish weight, fish density, and fish biomass) derived from the parrotfish assemblage and from an assemblage of highly valued commercial fish species to track changes in fishing pressure at spatial scales relevant to small Caribbean islands. Between June and August 2011, we conducted five consecutive visual fish surveys at six reefs ?10 km apart along the west coast of Barbados, representing a spatial gradient in fishing pressure. We used these data to identify the fish metrics most strongly correlated with fishing pressure and describe their functional relationship with fishing pressure. Overall, average individual parrotfish weight and biomass and density of commercial fish species were the metrics most strongly correlated with fishing pressure, although for the latter two, such correlations depended on the range of fish body sizes analyzed. Fishing pressure accounted for most of the variability in all correlated fish metrics (adj R 2 ? 0.75). However, functional relationships with fishing pressure differed qualitatively between metrics. In particular, average individual parrotfish weight was the metric most sensitive to incremental changes in fishing pressure. Overall, our study highlights that assemblage-level average individual parrotfish weight deserves a place in the toolbox of Caribbean reef managers as a simple indicator of both fishing effects on parrotfish assemblages and overall fishing pressure on the reef fish community.

  17. Immune-dependent antineoplastic effects of cisplatin plus pyridoxine in non-small-cell lung cancer.

    PubMed

    Aranda, F; Bloy, N; Pesquet, J; Petit, B; Chaba, K; Sauvat, A; Kepp, O; Khadra, N; Enot, D; Pfirschke, C; Pittet, M; Zitvogel, L; Kroemer, G; Senovilla, L

    2015-06-01

    cis-Diamminedichloroplatinum(II) (CDDP), which is mostly referred to as cisplatin, is a widely used antineoplastic. The efficacy of cisplatin can be improved by combining it with the vitamin B6 precursor pyridoxine. Here, we evaluated the putative synergistic interaction of CDDP with pyridoxine in the treatment of an orthotopic mouse model of non-small-cell lung cancer (NSCLC). CDDP and pyridoxine exhibited hyperadditive therapeutic effects. However, this synergy was only observed in the context of an intact immune system and disappeared when the otherwise successful drug combination was applied to the same NSCLC cancer implanted in the lungs of athymic mice (which lack T lymphocytes). Immunocompetent mice that had been cured from NSCLC by the combined regimen of CDDP plus pyridoxine became resistant against subcutaneous rechallenge with the same (but not with an unrelated) cancer cell line. In vitro, CDDP and pyridoxine did not only cause synergistic killing of NSCLC cells but also elicited signs of immunogenic cell death including an endoplasmic reticulum stress response and exposure of calreticulin at the surface of the NSCLC cells. NSCLC cells treated with CDDP plus pyridoxine in vitro elicited a protective anticancer immune response upon their injection into immunocompetent mice. Altogether, these results suggest that the combined regimen of cisplatin plus pyridoxine mediates immune-dependent antineoplastic effects against NSCLC. PMID:25065595

  18. Environmental Effects of Storage Preservation Practices: Controlled Flushing of Fine Sediment from a Small Hydropower Reservoir

    NASA Astrophysics Data System (ADS)

    Espa, Paolo; Castelli, Elena; Crosa, Giuseppe; Gentili, Gaetano

    2013-07-01

    Sediment flushing may be effective in mitigating loss of reservoir storage due to siltation, but flushing must be controlled to limit the impact on the downstream environment. A reliable prediction of the environmental effects of sediment flushing is hindered by the limited scientific information currently available. Consequently, there may be some controversy as regards to management decisions, planning the work, and monitoring strategies. This paper summarizes the main results of a monitoring campaign on the stream below a small alpine hydropower reservoir subjected to annual flushing between 2006 and 2009. The removed sediment was essentially silt, and the suspended solid concentration (SSC) of the discharged water was controlled to alleviate downstream impact. Control was achieved through hydraulic regulation and mechanical digging, alternating daytime sediment evacuation, and nocturnal clear water release. The four operations lasted about two weeks each and had an average SSC of about 4 g L-1. Maximum values of SSC were generally kept below 10 g L-1. Downstream impact was quantified through sampling of fish fauna (brown trout) and macroinvertebrate in the final reach of the effluent stream. The benthic community was severely impaired by the flushing operations, but recovered to pre-flushing values in a few months. As expected, the impact on brown trout was heavier on juveniles. While data biasing due to fish removal and re-stocking cannot be ruled out, the fish community seems to have reached a state of equilibrium characterized by a lower density than was measured before the flushing operations.

  19. Extending Improvement-Over-Chance "I"-Index Effect Size Simulation Studies to Cover Some Small-Sample Cases

    ERIC Educational Resources Information Center

    Natesan, Prathiba; Thompson, Bruce

    2007-01-01

    All effect sizes are sensitive to design flaws and the failure to meet analytic assumptions. But some effect sizes appear to be more robust to assumption violations (e.g., homogeneity of variance). The present study extended prior Monte Carlo research by exploring the robustness of group overlap "I" indices at the relatively small sample sizes…

  20. Effects of wood on debris flow runout in small mountain Stephen T. Lancaster and Shannon K. Hayes

    E-print Network

    Effects of wood on debris flow runout in small mountain watersheds Stephen T. Lancaster and Shannon 2002; revised 10 March 2003; accepted 25 March 2003; published 26 June 2003. [1] Debris flows have behavior are poorly understood. To evaluate whether wood can have a significant effect on debris flow

  1. The Effect of the Student Success Skills Small Group Counseling Intervention on Factors Associated with Dropout Potential in High School

    ERIC Educational Resources Information Center

    Weinstein, Jodie

    2013-01-01

    The focus of this study is to add to the outcome research on effective school counseling interventions and to specifically evaluate the effectiveness of the Student Success Skills (SSS) small group intervention with students identified as having drop out potential in the 9th grade. This study analyzed two years of pre-existing, non-identifiable…

  2. Effect of Clearcutting Operations on the Survival Rate of a Small Mammal

    PubMed Central

    Escobar, Martín A. H.; Uribe, Sandra V.; Chiappe, Romina; Estades, Cristián F.

    2015-01-01

    Clearcutting is a common timber harvesting technique that represents a significant and abrupt change in habitat conditions for wildlife living in industrial forests. Most research on this type of impact has focused on comparing populations or communities in mature forests/plantations and the resulting clearcut stands. However, this approach does not separate the effect of changes in habitat attributes from direct mortality produced by the intensive use of heavy machinery required for cutting down trees and dragging them to a road. Because knowing the fate of individuals after a disturbance is important for modelling landscape-scale population dynamics in industrial forests, we conducted a study in South-Central Chile to understand the short-term response to clearcutting operations of the long-haired Akodont (Abrothrix longipillis), a forest specialist mouse. Between 2009 and 2013 we radiotracked a total of 51 adult male Akodonts, before, during and after the clearcutting of the pine plantations in which they lived. A minimum of 52.4% of the individuals died as a direct cause of the timbering operations, being crushed by vehicles or logs during logging operations. Our observations suggest that, instead of fleeing the area, the response of long-haired Akodonts to the approaching machinery is to hide under the forest litter or in burrows, which exposes them to a serious risk of death. The real mortality rate associated to clearcutting may be higher than that estimated by us because of some methodological biases (i.e. individuals with crushed radiotransmitters not recorded) and the fact that additional mortality sources may affect the population in the weeks following logging operations (e.g. higher exposure to predation, effects of site preparation for the new plantation, etc). PMID:25748217

  3. Effects of octreotide on glucose transporter type 2 expression in obese rat small intestine

    PubMed Central

    Wei, Na; Liu, Rui; Ou, Yan; Li, Xian; Qiang, Ou; Guo, Wei; Tang, Cheng-Wei

    2011-01-01

    AIM: To investigate the effects of the somatostatin analogue, octreotide, on maltose and sucrase activities and expression of glucose transporter type 2 (GLUT2) in obese rat intestinal mucosa. METHODS: We divided 49 Sprague-Dawley rats into a group of 31 high fat diet-induced obese rats and a group of 18 normal controls. The obese rats were separated into an octreotide treated group of 16 rats and an obese group of 15. The intervention group was injected with octreotide at 40 ?g/kg body weight every 12 h for 8 d. Rat body weight was measured weekly to calculate Lee’s index. After euthanization, maltase and sucrase activities in the small intestine were measured by activity assays, and the fasting plasma glucose level was measured. The expression of GLUT2 in small intestinal mucosa was analyzed by immunohistochemistry, reverse transcriptase polymerase chain reaction and Western blotting assays. RESULTS: Body weight, Lee’s index, fasting plasma glucose level, maltase activity in small intestinal mucosa, mucosa and apical GLUT2, GLUT2 mRNA and protein expression levels were all significantly higher in the obese group than in the normal control group (605.61 ± 141.00 vs 378.54 ± 111.75, 337.61 ± 10.82 vs 318.73 ± 20.10, 8.60 ± 1.38 vs 7.33 ± 0.70, 156.01 ± 58.81 vs 50.43 ± 30.49, 390?744.2 ± 62?469.21 vs 170?546.50 ± 50?646.14, 26?740.18 ± 3809.60 vs 354.98 ± 57.19, 0.26 ± 0.11 vs 0.07 ± 0.02, and 2.08 ± 0.59 vs 1.27 ± 0.38, respectively, all P < 0.01). Sucrase activity did not differ between the two groups. Octreotide intervention significantly decreased the body weight and fasting plasma glucose level of obese rats (508.27 ± 94.39 vs 605.61 ± 141.00, 7.58 ± 1.51 vs 8.60 ±1.38, respectively, all P < 0.05). The intestinal mucosa and apical GLUT2, expression of GLUT2 mRNA and protein were also significantly lower in the octreotide intervention group than in the obese group (269?975.2 ± 53?730.94 vs 390?744.2 ± 62?469.21, 3758.06 ±364.51 vs 26?740.18 ± 3809.60, 0.08 ± 0.02 vs 0.26 ±0.11, and 1.31 ± 0.27 vs 2.08 ± 0.59, respectively, all P < 0.01). CONCLUSION: High fat diet-induced obesity is associated with elevated intestinal maltase activity, GLUT2 expression, and permanent apical GLUT2 in the small intestinal mucosa of rats. Octreotide can inhibit these effects. PMID:22110271

  4. Effects of instrument orientation on small-loop electromagnetic induction surveys of localized 2D conductive targets

    NASA Astrophysics Data System (ADS)

    Robledo, Fabiana Elizabeth; Martinelli, Hilda Patricia; Bonomo, Néstor Eduardo

    2011-12-01

    Frequency-domain electromagnetic induction (EMI) systems, composed of two coplanar small coils separated by a fixed distance (EMI or SLEM), enable the rapid detection of a great variety of near-surface structures. One coil generates a controlled, primary magnetic field and the other records the variations of the induced field while the instrument is moved over the studied area. The most usual acquisition configuration corresponds to horizontal coils, with the instrument axis parallel to the prospection lines. Usually, the interpretation is based on the direct visualization of the plan-views of the data measured at each frequency. In addition, to characterize the subsoil structure in-depth, 1D inversion methods are generally applied. The aim of this work is to analyse how the system orientation affects the ability of the method to detect localized, 2D conductive structures, buried at shallow depths, and the possibility of adequately characterizing these targets through 1D inversions. We performed a survey at a test site that contains two known structures of this type, buried in almost perpendicular directions. We performed parallel prospection lines in the direction of each structure, employing, aside from the usual configuration described before, other configurations that included horizontal and vertical coils, with the instrument axis parallel and perpendicular to the lines. For comparison, we also performed a geoelectric dipole-dipole line crossing one of the targets. The features of the anomalies observed in the graphs of the EMI apparent conductivity data strongly depend on the instrument orientation. In the horizontal coil configurations, a decrease of the apparent conductivity is observed just over the targets. Besides, each vertical configuration practically detects only the target aligned with the plane of the coils, as an important positive anomaly. Through numerical simulations, performed using a 2D forward modelling method, we demonstrate that these features are indeed 2D effects associated with the localized character of the studied conductive objects. Then, we applied to the data a 1D inversion method and drawing together the results generated pseudo 3D models of the subsoil. We found that the models obtained for the vertical coil configurations provide better results. They detect the targets as conductive structures and provide a rather good estimation of their depths. Finally, we compare the EMI results with the image obtained from the 2D inversion of the geoelectrical data and analyse the causes of the observed differences.

  5. Dosimetric effects on small-field beam-modeling for stereotactic body radiation therapy

    NASA Astrophysics Data System (ADS)

    Cho, Woong; Kim, Suzy; Kim, Jung-In; Wu, Hong-Gyun; Jung, Joo-Young; Kim, Min-Joo; Suh, Tae-Suk; Kim, Jin-Young; Kim, Jong Won

    2015-02-01

    The treatment planning of stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) requires high accuracy of dosimetric data for small radiation fields. The dosimetric effects on the beam-modeling process of a treatment planning system (TPS) were investigated using different measured small-field data sets. We performed small-field dosimetry with three detectors: a CC13 ion chamber, a CC01 ion chamber, and an edge detector. Percentage depth doses (PDDs) and dose profiles for field sizes given by 3 × 3 cm2, 2 × 2 cm2, and 1 × 1 cm2 were obtained for 6 MV and 15 MV photon beams. Each measured data set was used as data input for a TPS, in which a beam-modeling process was implemented using the collapsed cone convolution (CCC) algorithm for dose calculation. The measured data were used to generate six beam-models based on each combination of detector type and photon energy, which were then used to calculate the corresponding PDDs and dose profiles for various depths and field sizes. Root mean square differences (RMSDs) between the calculated and the measured doses were evaluated for the PDDs and the dose profiles. The RMSDs of PDDs beyond the maximum dose depth were within an accuracy of 0.2-0.6%, being clinically acceptable. The RMSDs of the dose profiles corresponding to the CC13, the CC01, and the edge detector were 2.80%, 1.49%, and 1.46% for a beam energy of 6 MV and 2.34%, 1.15%, and 1.44% for a beam energy of 15 MV, respectively. The calculated results for the CC13 ion chamber showed the most discrepancy compared to the measured data, due to the relatively large sensitive volume of this detector. However, the calculated dose profiles for the detectors were not significantly different from another. The physical algorithm used in the beam-modeling process did not seem to be sensitive to blurred data measured with detectors with large sensitive volumes. Each beam-model was used to clinically evaluate lung and lymphatic node SBRT plans, yielding almost equal dose distributions for the treatment targets, while the mean doses related to the organs at risk (OARs) deviated by approximately 0.7-1.2%. The use of the measured data sets from different detectors for the beam-modeling process still provided acceptable dose distributions with accuracies within 2%.

  6. Application of a multistate model to estimate culvert effects on movement of small fishes

    USGS Publications Warehouse

    Norman, J.R.; Hagler, M.M.; Freeman, Mary C.; Freeman, B.J.

    2009-01-01

    While it is widely acknowledged that culverted road-stream crossings may impede fish passage, effects of culverts on movement of nongame and small-bodied fishes have not been extensively studied and studies generally have not accounted for spatial variation in capture probabilities. We estimated probabilities for upstream and downstream movement of small (30-120 mm standard length) benthic and water column fishes across stream reaches with and without culverts at four road-stream crossings over a 4-6-week period. Movement and reach-specific capture probabilities were estimated using multistate capture-recapture models. Although none of the culverts were complete barriers to passage, only a bottomless-box culvert appeared to permit unrestricted upstream and downstream movements by benthic fishes based on model estimates of movement probabilities. At two box culverts that were perched above the water surface at base flow, observed movements were limited to water column fishes and to intervals when runoff from storm events raised water levels above the perched level. Only a single fish was observed to move through a partially embedded pipe culvert. Estimates for probabilities of movement over distances equal to at least the length of one culvert were low (e.g., generally ???0.03, estimated for 1-2-week intervals) and had wide 95% confidence intervals as a consequence of few observed movements to nonadjacent reaches. Estimates of capture probabilities varied among reaches by a factor of 2 to over 10, illustrating the importance of accounting for spatially variable capture rates when estimating movement probabilities with capture-recapture data. Longer-term studies are needed to evaluate temporal variability in stream fish passage at culverts (e.g., in relation to streamflow variability) and to thereby better quantify the degree of population fragmentation caused by road-stream crossings with culverts. ?? American Fisheries Society 2009.

  7. Spatial variation in keystone effects: Small mammal diversity associated with black-tailed prairie dog colonies

    USGS Publications Warehouse

    Cully, J.F.; Collinge, S.K.; Van Nimwegen, R. E.; Ray, C.; Johnson, W.C.; Thiagarajan, B.; Conlin, D.B.; Holmes, B.E.

    2010-01-01

    Species with extensive geographic ranges may interact with different species assemblages at distant locations, with the result that the nature of the interactions may vary spatially. Black-tailed prairie dogs Cynomys ludovicianus occur from Canada to Mexico in grasslands of the western Great Plains of North America. Black-tailed prairie dogs alter vegetation and dig extensive burrow systems that alter grassland habitats for plants and other animal species. These alterations of habitat justify the descriptor " ecological engineer," and the resulting changes in species composition have earned them status as a keystone species. We examined the impact of black-tailed prairie dogs on small mammal assemblages by trapping at on- and off-colony locations at eight study areas across the species' geographic range. We posed 2 nested hypotheses: 1) prairie dogs function as a keystone species for other rodent species; and 2) the keystone role varies spatially. Assuming that it does, we asked what are the sources of the variation? Black-tailed prairie dogs consistently functioned as a keystone species in that there were strong statistically significant differences in community composition on versus off prairie dog colonies across the species range in prairie grassland. Small mammal species composition varied along both latitudinal and longitudinal gradients, and species richness varied from 4 to 11. Assemblages closer together were more similar; such correlations approximately doubled when including only on- or off-colony grids. Black-tailed prairie dogs had a significant effect on associated rodent assemblages that varied regionally, dependent upon the composition of the local rodent species pool. Over the range of the black-tailed prairie dog, on-colony rodent richness and evenness were less variable, and species composition was more consistent than off-colony assemblages. ?? 2010 The Authors.

  8. Effect of experimental small-scale spatial heterogeneity on resource use of a Mediterranean ground-ant community

    NASA Astrophysics Data System (ADS)

    M. Luque, Gloria; Reyes López, Joaquín

    2007-07-01

    Small-scale habitat complexity has been shown to influence interspecific competition and resource use in ant communities. Nevertheless, in Mediterranean communities, where temperature variations have a stronger effect on the foraging of subordinate species than competition by dominants, the effect of small-scale habitat complexity on resource use by ants is unknown. We investigated the influence of an experimental spatial mosaic of microhabitats (interior, edge and open) on the dynamics of resource use in a guild of ants of a Mediterranean grassland. We used baits containing one of three food resource types (honey, tuna and seeds) placed in the different microhabitats. Variation in resource use among microhabitats appears to result from differential responses among ant species to small-scale spatial heterogeneity. Analysis of frequency of occurrence, number of foragers and monopoly at baits of ant species indicated that the resource use and recruitment intensity was modified by microhabitat, once the effect of temperature was removed from the analysis. Thus, foraging activity and competitive interactions of ant species were influenced by the different microhabitats apart from temperature, which suggests an effect of small-scale structural complexity. Small-scale spatial variations in structural complexity have an effect in resource use by most ants in this system that is not wholly explained by differences in temperature. Finally, this suggests that microhabitat may be one factor influencing the outcome of the dominance hierarchies.

  9. Effect of contrast on the perceived direction of a moving plaid

    NASA Technical Reports Server (NTRS)

    Stone, L. S.; Watson, A. B.; Mulligan, J. B.

    1990-01-01

    A series of experiments examining the effect of contrast on the perception of moving plaids is performed. This was done to test the hypothesis put forth by Adelson and Movshon (1982) that the human visual system determines the direction of a moving plaid in a two-staged process: decomposition into component motion followed by application of the intersection of constraints rule. When the gratings within the plaid are of different contrast, the perceived direction is not predicted by the intersection of constraints rule. There is a strong (up to 20 deg) bias in the direction of the higher-contrast grating. A revised model, which incorporates a contrast-dependent weighting of perceived grating speed as observed for one-dimensional patterns (Thompson, 1982), can quantitatively predict most of the results. Results are discussed in the context of various models of human visual motion processing and of physiological responses of neurons in the primate visual system.

  10. FREQ-Seq: A Rapid, Cost-Effective, Sequencing-Based Method to Determine Allele Frequencies Directly from Mixed Populations

    PubMed Central

    Delaney, Nigel F.; Marx, Christopher J.

    2012-01-01

    Understanding evolutionary dynamics within microbial populations requires the ability to accurately follow allele frequencies through time. Here we present a rapid, cost-effective method (FREQ-Seq) that leverages Illumina next-generation sequencing for localized, quantitative allele frequency detection. Analogous to RNA-Seq, FREQ-Seq relies upon counts from the >105 reads generated per locus per time-point to determine allele frequencies. Loci of interest are directly amplified from a mixed population via two rounds of PCR using inexpensive, user-designed oligonucleotides and a bar-coded bridging primer system that can be regenerated in-house. The resulting bar-coded PCR products contain the adapters needed for Illumina sequencing, eliminating further library preparation. We demonstrate the utility of FREQ-Seq by determining the order and dynamics of beneficial alleles that arose as a microbial population, founded with an engineered strain of Methylobacterium, evolved to grow on methanol. Quantifying allele frequencies with minimal bias down to 1% abundance allowed effective analysis of SNPs, small in-dels and insertions of transposable elements. Our data reveal large-scale clonal interference during the early stages of adaptation and illustrate the utility of FREQ-Seq as a cost-effective tool for tracking allele frequencies in populations. PMID:23118913

  11. Effect of cortisone treatment on the active transport of calcium by the small intestine

    PubMed Central

    Kimberg, Daniel V.; Baerg, Richard D.; Gershon, Elaine; Graudusius, Ruta T.

    1971-01-01

    It is generally recognized that glucocorticoid administration may diminish calcium absorption in vivo as well as the active transport of calcium by the intestine in vitro. Recent studies by others have emphasized the possibility of an alteration in the metabolism of vitamin D to 25-hydroxycholecalciferol in accounting for the steroid effects on calcium absorption. The results obtained in the present studies fail to support this hypothesis. The present studies confirm that the administration of cortisone or other glucocorticoids to the rat interferes with the active transport of calcium by duodenal gut sacs in vitro. This abnormality is not due to an alteration in the permeability of the intestine to calcium, and it cannot be corrected by the administration of either massive doses of vitamin D2 or modest doses of 25-hydroxycholecalciferol. Experiments concerned with the effects of cortisone on the level of the vitamin D-dependent duodenal calcium-binding protein, the amount of bioassayable vitamin D activity in the mucosa, and the distribution and metabolism of 3H-vitamin D3, did not provide evidence in favor of a harmone-related defect in either the localization of vitamin D or its metabolism to 25-hydroxycholecalciferol. Alterations in the transport of iron and D-galactose, not dependent on vitamin D, suggest that cortisone treatment may be responsible for more than a simple antagonism to the effects of vitamin D. The results of the present studies indicate that cortisone administration affects the cellular mechanisms mediating calcium transport in a manner that is opposite to the effects of vitamin D, but seems to be independent of any direct interaction with the parent vitamin or its metabolites. If a disorder in vitamin D metabolism is at all involved, it is at a step subsequent to 25-hydroxylation. PMID:4325312

  12. Directional effects on NDVI and LAI retrievals from MODIS: A case study in Brazil with soybean

    NASA Astrophysics Data System (ADS)

    Breunig, Fábio Marcelo; Galvão, Lênio Soares; Formaggio, Antônio Roberto; Epiphanio, José Carlos Neves

    2011-02-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) is largely used to estimate Leaf Area Index (LAI) using radiative transfer modeling (the "main" algorithm). When this algorithm fails for a pixel, which frequently occurs over Brazilian soybean areas, an empirical model (the "backup" algorithm) based on the relationship between the Normalized Difference Vegetation Index (NDVI) and LAI is utilized. The objective of this study is to evaluate directional effects on NDVI and subsequent LAI estimates using global (biome 3) and local empirical models, as a function of the soybean development in two growing seasons (2004-2005 and 2005-2006). The local model was derived from the pixels that had LAI values retrieved from the main algorithm. In order to keep the reproductive stage for a given cultivar as a constant factor while varying the viewing geometry, pairs of MODIS images acquired in close dates from opposite directions (backscattering and forward scattering) were selected. Linear regression relationships between the NDVI values calculated from these two directions were evaluated for different view angles (0-25°; 25-45°; 45-60°) and development stages (<45; 45-90; >90 days after planting). Impacts on LAI retrievals were analyzed. Results showed higher reflectance values in backscattering direction due to the predominance of sunlit soybean canopy components towards the sensor and higher NDVI values in forward scattering direction due to stronger shadow effects in the red waveband. NDVI differences between the two directions were statistically significant for view angles larger than 25°. The main algorithm for LAI estimation failed in the two growing seasons with gradual crop development. As a result, up to 94% of the pixels had LAI values calculated from the backup algorithm at the peak of canopy closure. Most of the pixels selected to compose the 8-day MODIS LAI product came from the forward scattering view because it displayed larger LAI values than the backscattering. Directional effects on the subsequent LAI retrievals were stronger at the peak of the soybean development (NDVI values between 0.70 and 0.85). When the global empirical model was used, LAI differences up to 3.2 for consecutive days and opposite viewing directions were observed. Such differences were reduced to values up to 1.5 with the local model. Because of the predominance of LAI retrievals from the MODIS backup algorithm during the Brazilian soybean development, care is necessary if one considers using these data in agronomic growing/yield models.

  13. Cytoprotective effect of selective small-molecule caspase inhibitors against staurosporine-induced apoptosis

    PubMed Central

    Wu, Jianghong; Wang, Yuren; Liang, Shuguang; Ma, Haiching

    2014-01-01

    Caspases are currently known as the central executioners of the apoptotic pathways. Inhibition of apoptosis and promotion of normal cell survival by caspase inhibitors would be a tremendous benefit for reducing the side effects of cancer therapy and for control of neurodegenerative disorders such as Parkinson’s, Alzheimer’s, and Huntington’s diseases. The objective of this study was to discover small-molecule caspase inhibitors with which to achieve cytoprotective effect. We completed the high-throughput screening of Bionet’s 37,500-compound library (Key Organics Limited, Camelford, Cornwall, UK) against caspase-1, -3, and -9 and successfully identified 43 initial hit compounds. The 43 hit compounds were further tested for cytoprotective activity against staurosporine-induced cell death in NIH3T3 cells. Nineteen compounds were found to have significant cytoprotective effects in cell viability assays. One of the compounds, RBC1023, was demonstrated to protect NIH3T3 cells from staurosporine-induced caspase-3 cleavage and activation. RBC1023 was also shown to protect against staurosporine-induced impairment of mitochondrial membrane potential. DNA microarray analysis demonstrated that staurosporine treatment induced broad global gene expression alterations, and RBC1023 co-treatment significantly restored these changes, especially of the genes that are related to cell growth and survival signaling such as Egr1, Cdc25c, cdkn3, Rhob, Nek2, and Taok1. Collectively, RBC1023 protects NIH3T3 cells against staurosporine-induced apoptosis via inhibiting caspase activity, restoring mitochondrial membrane potential, and possibly upregulating some cell survival-related gene expressions and pathways. PMID:24920883

  14. Novel small-molecule AMPK activator orally exerts beneficial effects on diabetic db/db mice

    SciTech Connect

    Li, Yuan-Yuan; Yu, Li-Fang; Zhang, Li-Na; Qiu, Bei-Ying; Su, Ming-Bo; Wu, Fang; Chen, Da-Kai; Pang, Tao; Gu, Min; Zhang, Wei; Ma, Wei-Ping; Jiang, Hao-Wen; Li, Jing-Ya Nan, Fa-Jun Li, Jia

    2013-12-01

    AMP-activated protein kinase (AMPK), which is a pivotal guardian of whole-body energy metabolism, has become an attractive therapeutic target for metabolic syndrome. Previously, using a homogeneous scintillation proximity assay, we identified the small-molecule AMPK activator C24 from an optimization based on the original allosteric activator PT1. In this paper, the AMPK activation mechanism of C24 and its potential beneficial effects on glucose and lipid metabolism on db/db mice were investigated. C24 allosterically stimulated inactive AMPK ? subunit truncations and activated AMPK heterotrimers by antagonizing autoinhibition. In primary hepatocytes, C24 increased the phosphorylation of AMPK downstream target acetyl-CoA carboxylase dose-dependently without changing intracellular AMP/ATP ratio, indicating its allosteric activation in cells. Through activating AMPK, C24 decreased glucose output by down-regulating mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in primary hepatocytes. C24 also decreased the triglyceride and cholesterol contents in HepG2 cells. Due to its improved bioavailability, chronic oral treatment with multiple doses of C24 significantly reduced blood glucose and lipid levels in plasma, and improved the glucose tolerance of diabetic db/db mice. The hepatic transcriptional levels of PEPCK and G6Pase were reduced. These results demonstrate that this orally effective activator of AMPK represents a novel approach to the treatment of metabolic syndrome. - Highlights: • C24 activates AMPK through antagonizing autoinhibition within ? subunit. • C24 activates AMPK in hepatocytes and decreases glucose output via AMPK. • C24 exerts beneficial effects on diabetic db/db mice. • C24 represents a novel therapeutic for treatment of metabolic syndrome.

  15. The effect of the small Indian mongoose (Urva auropunctatus), island quality and habitat on the distribution of native and endemic birds on small islands within Fiji.

    PubMed

    Morley, Craig G; Winder, Linton

    2013-01-01

    This study investigated the effect of the presence of introduced mongoose, environmental quality and habitat on the distribution of native and endemic birds on 16 small islands within Fiji. In total, 9055 birds representing 45 species were observed within four key habitats (forest, villages, crop land and coastal vegetation) on the 16 islands, half of which had mongoose present. Previous studies attribute bird declines and extirpation anecdotally to the mongoose. The presence of mongoose, environmental quality and habitat type had a measurable influence on observed extant native and endemic bird communities. We conclude that three ground birds; Gallirallus phillipensis, Anas supericiliosa and Porphyrio porhyrio were negatively influenced by the presence of mongoose and that Ptilinopus perousii, Phigys solitarius, Chrysoenas victor, Ducula latrans, Clytorhyrchus vitiensis, Pachycephala pectoralis, Prospeia tabunesis, and Foulehaio carunculata were particularly dependent on good quality forest habitat. Conservation priorities in relation to protecting Fiji's endemic birds from the effect of mongoose are discussed and preventative measures suggested. PMID:23349751

  16. The Effect of the Small Indian Mongoose (Urva auropunctatus), Island Quality and Habitat on the Distribution of Native and Endemic Birds on Small Islands within Fiji

    PubMed Central

    Morley, Craig G.; Winder, Linton

    2013-01-01

    This study investigated the effect of the presence of introduced mongoose, environmental quality and habitat on the distribution of native and endemic birds on 16 small islands within Fiji. In total, 9055 birds representing 45 species were observed within four key habitats (forest, villages, crop land and coastal vegetation) on the 16 islands, half of which had mongoose present. Previous studies attribute bird declines and extirpation anecdotally to the mongoose. The presence of mongoose, environmental quality and habitat type had a measurable influence on observed extant native and endemic bird communities. We conclude that three ground birds; Gallirallus phillipensis, Anas supericiliosa and Porphyrio porhyrio were negatively influenced by the presence of mongoose and that Ptilinopus perousii, Phigys solitarius, Chrysoenas victor, Ducula latrans, Clytorhyrchus vitiensis, Pachycephala pectoralis, Prospeia tabunesis, and Foulehaio carunculata were particularly dependent on good quality forest habitat. Conservation priorities in relation to protecting Fiji's endemic birds from the effect of mongoose are discussed and preventative measures suggested. PMID:23349751

  17. Possible altitudinal, latitudinal and directional dependence of relativistic Sagnac effect in Chern-Simons modified gravity

    E-print Network

    Daiki Kikuchi; Naoya Omoto; Kei Yamada; Hideki Asada

    2014-09-07

    Toward a test of parity violation in a gravity theory, possible effects of Chern-Simons (CS) gravity on an interferometer have been recently discussed. Continuing work initiated in an earlier publication [Okawara, Yamada and Asada, Phys. Rev. Lett. 109, 231101 (2012)], we study possible altitudinal and directional dependence of relativistic Sagnac effect in CS modified gravity. We compare the CS effects on Sagnac interferometers with the general relativistic Lense-Thirring (LT) effects. Numerical calculations show that the eastbound Sagnac interferometer might be preferred for testing CS separately, because LT effects on this interferometer cancel out. The size of the phase shift induced in the CS model might have an oscillatory dependence also on the altitude of the interferometer through the CS mass parameter $m_{CS}$. Therefore, the international space station site as well as a ground-based experiment is also discussed.

  18. Direct test of the MSW effect by the solar appearance term in beam experiments

    E-print Network

    Walter Winter

    2005-04-22

    We discuss if one can verify the MSW effect in neutrino oscillations at a high confidence level in long-baseline experiments. We demonstrate that for long enough baselines at neutrino factories, the matter effect sensitivity is, as opposed to the mass hierarchy sensitivity, not suppressed by $\\sin^2 2 \\theta_{13}$ because it is driven by the solar oscillations in the appearance probability. Furthermore, we show that for the parameter independent direct verification of the MSW effect at long-baseline experiments, a neutrino factory with a baseline of at least 6000 km is needed. For superbeams, we do not find a $5\\sigma$ discovery potential of the MSW effect independent of $\\sin^2 2 \\theta_{13}$. We finally summarize different methods to test the MSW effect.

  19. Test of direct and indirect effects of agrochemicals on the survival of fecal indicator bacteria.

    PubMed

    Staley, Zachery R; Rohr, Jason R; Harwood, Valerie J

    2011-12-01

    Water bodies often receive agrochemicals and animal waste carrying fecal indicator bacteria (FIB) and zoonotic pathogens, but we know little about the effects of agrochemicals on these microbes. We assessed the direct effects of the pesticides atrazine, malathion, and chlorothalonil and inorganic fertilizer on Escherichia coli and enterococcal survival in simplified microcosms held in the dark. E. coli strain composition in sediments and water column were positively correlated, but none of the agrochemicals had significant direct effects on E. coli strain composition or on densities of culturable FIBs. In a companion study, microcosms with nondisinfected pond water and sediments were exposed to or shielded from sunlight to examine the potential indirect effects of atrazine and inorganic fertilizer on E. coli. The herbicide atrazine had no effect on E. coli in dark-exposed microcosms containing natural microbial and algal communities. However, in light-exposed microcosms, atrazine significantly lowered E. coli densities in the water column and significantly increased densities in the sediment compared to controls. This effect appears to be mediated by the effects of atrazine on algae, given that atrazine significantly reduced phytoplankton, which was a positive and negative predictor of E. coli densities in the water column and sediment, respectively. These data suggest that atrazine does not directly affect the survival of FIB, rather that it indirectly alters the distribution and abundance of E. coli by altering phytoplankton and periphyton communities. These results improve our understanding of the influence of agricultural practices on FIB densities in water bodies impacted by agricultural runoff. PMID:22003017

  20. Are regulatory strategies necessary in the regulation of accuracy? The effect of direct-access answers.

    PubMed

    Luna, Karlos; Martín-Luengo, Beatriz; Brewer, Neil

    2015-11-01

    Previous studies have shown that, when people asked to retrieve something from memory have the chance to regulate memory accuracy, the accuracy of their final report increases. Such regulation of accuracy can be made through one of several strategies: the report option, the grain-size option, or the plurality option. However, sometimes an answer can be directly accessed and reported without resorting to such strategies. The direct-access answers are expected to be fast, have high accuracy, and be rated with high probabilities of being correct. Thus, direct-access answers alone could explain the increase of accuracy that has been considered the outcome of regulatory strategies. If so, regulatory strategies may not be needed to explain the previous results. In two experiments, we disentangled the effects of direct-access answers and regulatory strategies in the increase of accuracy. We identified a subset of direct-access answers, and then examined the regulation of accuracy with the plurality option when they were removed. Participants answered questions with six (Exp. 1) or five (Exp. 2) alternatives. Their task was, first, to select as many alternatives as they wanted and, second, to select only two or four alternatives. The results showed that the direct-access answer affected the regulation of accuracy and made it easier. However, the results also showed that regulatory strategies, in this case the plurality option, are needed to explain why the accuracy of final report increases after successful regulation. This research highlighted the relevance of taking direct-access answers into account in the study of the regulation of accuracy. PMID:26148719

  1. The effect of current flow direction on motor hot spot allocation by transcranial magnetic stimulation.

    PubMed

    Stephani, Caspar; Paulus, Walter; Sommer, Martin

    2016-01-01

    The objective of this study was to investigate the significance of pulse configurations and current direction for corticospinal activation using transcranial magnetic stimulation (TMS). In 11 healthy subjects (8 female), a motor map for the motor evoked potentials (MEPs) recorded from the first dorsal interosseus (FDI), abductor digiti minimi (ADM), extensor carpi radialis, and biceps brachii (BB) muscles of the dominant side was established. Starting from a manually determined hot spot of the FDI representation, we measured MEPs at equal oriented points on an hexagonal grid, with 7 MEPs recorded at each point, using the following pulse configurations: posteriorly directed monophasic (Mo-P), anteriorly directed monophasic (Mo-A), biphasic with the more relevant second cycle oriented posteriorly (Bi-P) as well as a reversed biphasic condition (Bi-A). For each pulse configuration, a hot spot was determined and a center of gravity (CoG) was calculated. We found that the factor current direction had an effect on location of the CoG-adjusted hot spot in the cranio-caudal axis but not in the latero-medial direction with anteriorly directed pulses locating the CoG more anteriorly and vice versa. In addition, the CoG for the FDI was more laterally than the cortical representations for the abductor digiti minimi (ADM) and extensor carpi radialis (ECR) which were registered as well. The results indicate that direction of the current pulse should be taken into account for determination of the motor representation of a muscle by TMS. PMID:26733248

  2. The Effects of Methylphenidate on Goal-directed Behavior in a Rat Model of ADHD

    PubMed Central

    Natsheh, Joman Y.; Shiflett, Michael W.

    2015-01-01

    Although attentional and motor alterations in Attention Deficit Hyperactivity Disorder (ADHD) have been well characterized, less is known about how this disorder impacts goal-directed behavior. To investigate whether there is a misbalance between goal-directed and habitual behaviors in an animal model of ADHD, we tested adult [P75–P105] Spontaneously Hypertensive Rats (SHR; ADHD rat model) and Wistar–Kyoto rats (WKY), the normotensive control strain, on an instrumental conditioning paradigm with two phases: a free-operant training phase in which rats separately acquired two distinct action–outcome contingencies, and a choice test conducted in extinction prior to which one of the food outcomes was devalued through specific satiety. To assess the effects of Methylphenidate (MPH), a commonly used ADHD medication, on goal-directed behavior, we injected rats with either MPH or saline prior to the choice test. Both rat strains acquired an instrumental response, with SHR responding at greater rates over the course of training. During the choice test WKY demonstrated goal-directed behavior, responding more frequently on the lever that delivered, during training, the still-valued outcome. In contrast, SHR showed no goal-directed behavior, responding equally on both levers. However, MPH administration prior to the choice test restored goal-directed behavior in SHR, and disrupted this behavior in WKY rats. This study provides the first experimental evidence for selective impairment in goal-directed behavior in rat models of ADHD, and how MPH acts differently on SHR and WKY animals to restore or impair this behavior, respectively. PMID:26635568

  3. Effect of signal-to-noise ratio on directional microphone benefit and preference.

    PubMed

    Walden, Brian E; Surr, Rauna K; Grant, Kenneth W; Van Summers, W; Cord, Mary T; Dyrlund, Ole

    2005-10-01

    This study examined speech intelligibility and preferences for omnidirectional and directional microphone hearing aid processing across a range of signal-to-noise ratios (SNRs). A primary motivation for the study was to determine whether SNR might be used to represent distance between talker and listener in automatic directionality algorithms based on scene analysis. Participants were current hearing aid users who either had experience with omnidirectional microphone hearing aids only or with manually switchable omnidirectional/directional hearing aids. Using IEEE/Harvard sentences from a front loudspeaker and speech-shaped noise from three loudspeakers located behind and to the sides of the listener, the directional advantage (DA) was obtained at 11 SNRs ranging from -15 dB to +15 dB in 3 dB steps. Preferences for the two microphone modes at each of the 11 SNRs were also obtained using concatenated IEEE sentences presented in the speech-shaped noise. Results revealed that a DA was observed across a broad range of SNRs, although directional processing provided the greatest benefit within a narrower range of SNRs. Mean data suggested that microphone preferences were determined largely by the DA, such that the greater the benefit to speech intelligibility provided by the directional microphones, the more likely the listeners were to prefer that processing mode. However, inspection of the individual data revealed that highly predictive relationships did not exist for most individual participants. Few preferences for omnidirectional processing were observed. Overall, the results did not support the use of SNR to estimate the effects of distance between talker and listener in automatic directionality algorithms. PMID:16515138

  4. Effect of intermodular connection on fast sparse synchronization in clustered small-world neural networks

    NASA Astrophysics Data System (ADS)

    Kim, Sang-Yoon; Lim, Woochang

    2015-11-01

    We consider a clustered network with small-world subnetworks of inhibitory fast spiking interneurons and investigate the effect of intermodular connection on the emergence of fast sparsely synchronized rhythms by varying both the intermodular coupling strength Jinter and the average number of intermodular links per interneuron Msyn(inter ). In contrast to the case of nonclustered networks, two kinds of sparsely synchronized states such as modular and global synchronization are found. For the case of modular sparse synchronization, the population behavior reveals the modular structure, because the intramodular dynamics of subnetworks make some mismatching. On the other hand, in the case of global sparse synchronization, the population behavior is globally identical, independently of the cluster structure, because the intramodular dynamics of subnetworks make perfect matching. We introduce a realistic cross-correlation modularity measure, representing the matching degree between the instantaneous subpopulation spike rates of the subnetworks, and examine whether the sparse synchronization is global or modular. Depending on its magnitude, the intermodular coupling strength Jinter seems to play "dual" roles for the pacing between spikes in each subnetwork. For large Jinter, due to strong inhibition it plays a destructive role to "spoil" the pacing between spikes, while for small Jinter it plays a constructive role to "favor" the pacing between spikes. Through competition between the constructive and the destructive roles of Jinter, there exists an intermediate optimal Jinter at which the pacing degree between spikes becomes maximal. In contrast, the average number of intermodular links per interneuron Msyn(inter ) seems to play a role just to favor the pacing between spikes. With increasing Msyn(inter ), the pacing degree between spikes increases monotonically thanks to the increase in the degree of effectiveness of global communication between spikes. Furthermore, we employ the realistic sub- and whole-population order parameters, based on the instantaneous sub- and whole-population spike rates, to determine the threshold values for the synchronization-unsynchronization transition in the sub- and whole populations, and the degrees of global and modular sparse synchronization are also measured in terms of the realistic sub- and whole-population statistical-mechanical spiking measures defined by considering both the occupation and the pacing degrees of spikes. It is expected that our results could have implications for the role of the brain plasticity in some functional behaviors associated with population synchronization.

  5. Origin of the structure-directing effect resulting in identical topological open-framework materials

    PubMed Central

    Xin, Liang; Sun, Huai; Xu, Ruren; Yan, Wenfu

    2015-01-01

    In the synthesis of zeolites and related crystalline materials with open-frameworks, a single structure is obtained in the presence of many different templates, known as the “one-structure/multiple-templates” phenomenon. However, the reasons behind this phenomenon have yet to be elucidated. By analyzing the possible starting point of crystallization in several “one-structure/multiple-templates” systems and applying the molecular dynamics simulation to such systems, we found that the template-framework binding free energy level or charge transfer (exchange) degree was the key to the structure-directing effect of a template. This discovery explains why the structure-directing effect of a template can be affected by many variables, such as the nature of the source materials, molar composition of the initial reaction mixture (recipe), mineralizers, type of solvent, and heating temperature. In the synthesis of zeolites and related crystalline materials with open-frameworks, the template or organic additive played a topological structure-directing role instead of a structure-directing role. PMID:26447528

  6. Origin of the structure-directing effect resulting in identical topological open-framework materials

    NASA Astrophysics Data System (ADS)

    Xin, Liang; Sun, Huai; Xu, Ruren; Yan, Wenfu

    2015-10-01

    In the synthesis of zeolites and related crystalline materials with open-frameworks, a single structure is obtained in the presence of many different templates, known as the “one-structure/multiple-templates” phenomenon. However, the reasons behind this phenomenon have yet to be elucidated. By analyzing the possible starting point of crystallization in several “one-structure/multiple-templates” systems and applying the molecular dynamics simulation to such systems, we found that the template-framework binding free energy level or charge transfer (exchange) degree was the key to the structure-directing effect of a template. This discovery explains why the structure-directing effect of a template can be affected by many variables, such as the nature of the source materials, molar composition of the initial reaction mixture (recipe), mineralizers, type of solvent, and heating temperature. In the synthesis of zeolites and related crystalline materials with open-frameworks, the template or organic additive played a topological structure-directing role instead of a structure-directing role.

  7. Direct water heater load control - Estimating program effectiveness using an engineering model

    SciTech Connect

    Gustafson, M.W. ); Baylor, J.S. ); Epstein, G. )

    1993-02-01

    Most utility demand-side management strategies that involve direct load control have been developed using a pilot testing or demonstration program. Two appliances, electric water heaters and air conditioners, are the primary candidates for direct utility control. A utility can avoid pilot testing programs and proceed directly to program implementation if it designs and conducts a proper load research program in which average customer usage and instantaneous demand are determined as a function of the variables that affect each of them. This paper describes a method to evaluate the potential effectiveness of a direct water heater load control program. Developed through a comprehensive load research program coupled with engineering insights into the energy use of the residential hot water systems, this method results in an algorithm that has been utilized to evaluate the potential for load control on three utility systems in the western US. Variables to be monitored through the load research are presented and a procedure is developed that will allow the system planner to determine if such a program will be cost-effective and successful compared to a program developed through a more traditional pilot or demonstration approach. This paper also outlined how the same methodology can be used for determining a procedure for the dispatcher to properly initiate and terminate a load control program without hot water recovery problems.

  8. Origin of the structure-directing effect resulting in identical topological open-framework materials.

    PubMed

    Xin, Liang; Sun, Huai; Xu, Ruren; Yan, Wenfu

    2015-01-01

    In the synthesis of zeolites and related crystalline materials with open-frameworks, a single structure is obtained in the presence of many different templates, known as the "one-structure/multiple-templates" phenomenon. However, the reasons behind this phenomenon have yet to be elucidated. By analyzing the possible starting point of crystallization in several "one-structure/multiple-templates" systems and applying the molecular dynamics simulation to such systems, we found that the template-framework binding free energy level or charge transfer (exchange) degree was the key to the structure-directing effect of a template. This discovery explains why the structure-directing effect of a template can be affected by many variables, such as the nature of the source materials, molar composition of the initial reaction mixture (recipe), mineralizers, type of solvent, and heating temperature. In the synthesis of zeolites and related crystalline materials with open-frameworks, the template or organic additive played a topological structure-directing role instead of a structure-directing role. PMID:26447528

  9. A Unifying Review of Bioassay-Guided Fractionation, Effect-Directed Analysis and Related Techniques

    PubMed Central

    Weller, Michael G.

    2012-01-01

    The success of modern methods in analytical chemistry sometimes obscures the problem that the ever increasing amount of analytical data does not necessarily give more insight of practical relevance. As alternative approaches, toxicity- and bioactivity-based assays can deliver valuable information about biological effects of complex materials in humans, other species or even ecosystems. However, the observed effects often cannot be clearly assigned to specific chemical compounds. In these cases, the establishment of an unambiguous cause-effect relationship is not possible. Effect-directed analysis tries to interconnect instrumental analytical techniques with a biological/biochemical entity, which identifies or isolates substances of biological relevance. Successful application has been demonstrated in many fields, either as proof-of-principle studies or even for complex samples. This review discusses the different approaches, advantages and limitations and finally shows some practical examples. The broad emergence of effect-directed analytical concepts might lead to a true paradigm shift in analytical chemistry, away from ever growing lists of chemical compounds. The connection of biological effects with the identification and quantification of molecular entities leads to relevant answers to many real life questions. PMID:23012539

  10. Effect of Fuel Fraction on Small Modified CANDLE Burn-up Based Gas Cooled Fast Reactors

    SciTech Connect

    Ariani, Menik; Su'ud, Zaki; Waris, Abdul; Asiah, Nur; Shafii, M. Ali; Khairurrijal

    2010-12-23

    A conceptual design study of Gas Cooled Fast Reactors with Modified CANDLE Burn-up has been performed. The objective of this research is to get optimal design parameters of such type reactors. The parameters of nuclear design including the critical condition, conversion ratio, and burn-up level were compared. These parameters are calculated by variation in the fuel fraction 47.5% up to 70%. Two dimensional full core multi groups diffusion calculations was performed by CITATION code. Group constant preparations are performed by using SRAC code system with JENDL-3.2 nuclear data library. In this design the reactor cores with cylindrical cell two dimensional R-Z core models are subdivided into several parts with the same volume in the axial directions. The placement of fuel in core arranged so that the result of plutonium from natural uranium can be utilized optimally for 10 years reactor operation. Modified CANDLE burn-up was established successfully in a core radial width 1.4 m. Total thermal power output for reference core is 550 MW. Study on the effect of fuel to coolant ratio shows that effective multiplication factor (k{sub eff}) is in almost linear relations with the change of the fuel volume to coolant ratio.

  11. Polarity Specific Suppression Effects of Transcranial Direct Current Stimulation for Tinnitus

    PubMed Central

    Van de Heyning, Paul; Vanneste, Sven

    2014-01-01

    Tinnitus is the perception of a sound in the absence of an external auditory stimulus and affects 10–15% of the Western population. Previous studies have demonstrated the therapeutic effect of anodal transcranial direct current stimulation (tDCS) over the left auditory cortex on tinnitus loudness, but the effect of this presumed excitatory stimulation contradicts with the underlying pathophysiological model of tinnitus. Therefore, we included 175 patients with chronic tinnitus to study polarity specific effects of a single tDCS session over the auditory cortex (39 anodal, 136 cathodal). To assess the effect of treatment, we used the numeric rating scale for tinnitus loudness and annoyance. Statistical analysis demonstrated a significant main effect for tinnitus loudness and annoyance, but for tinnitus annoyance anodal stimulation has a significantly more pronounced effect than cathodal stimulation. We hypothesize that the suppressive effect of tDCS on tinnitus loudness may be attributed to a disrupting effect of ongoing neural hyperactivity, independent of the inhibitory or excitatory effects and that the reduction of annoyance may be induced by influencing adjacent or functionally connected brain areas involved in the tinnitus related distress network. Further research is required to explain why only anodal stimulation has a suppressive effect on tinnitus annoyance. PMID:24812586

  12. Polarity specific suppression effects of transcranial direct current stimulation for tinnitus.

    PubMed

    Joos, Kathleen; De Ridder, Dirk; Van de Heyning, Paul; Vanneste, Sven

    2014-01-01

    Tinnitus is the perception of a sound in the absence of an external auditory stimulus and affects 10-15% of the Western population. Previous studies have demonstrated the therapeutic effect of anodal transcranial direct current stimulation (tDCS) over the left auditory cortex on tinnitus loudness, but the effect of this presumed excitatory stimulation contradicts with the underlying pathophysiological model of tinnitus. Therefore, we included 175 patients with chronic tinnitus to study polarity specific effects of a single tDCS session over the auditory cortex (39 anodal, 136 cathodal). To assess the effect of treatment, we used the numeric rating scale for tinnitus loudness and annoyance. Statistical analysis demonstrated a significant main effect for tinnitus loudness and annoyance, but for tinnitus annoyance anodal stimulation has a significantly more pronounced effect than cathodal stimulation. We hypothesize that the suppressive effect of tDCS on tinnitus loudness may be attributed to a disrupting effect of ongoing neural hyperactivity, independent of the inhibitory or excitatory effects and that the reduction of annoyance may be induced by influencing adjacent or functionally connected brain areas involved in the tinnitus related distress network. Further research is required to explain why only anodal stimulation has a suppressive effect on tinnitus annoyance. PMID:24812586

  13. Binding Studies on Isolated Porcine Small Intestinal Mucosa and in vitro Toxicity Studies Reveal Lack of Effect of C. perfringens Beta-Toxin on the Porcine Intestinal Epithelium

    PubMed Central

    Roos, Simone; Wyder, Marianne; Candi, Ahmet; Regenscheit, Nadine; Nathues, Christina; van Immerseel, Filip; Posthaus, Horst

    2015-01-01

    Beta-toxin (CPB) is the essential virulence factor of C. perfringens type C causing necrotizing enteritis (NE) in different hosts. Using a pig infection model, we showed that CPB targets small intestinal endothelial cells. Its effect on the porcine intestinal epithelium, however, could not be adequately investigated by this approach. Using porcine neonatal jejunal explants and cryosections, we performed in situ binding studies with CPB. We confirmed binding of CPB to endothelial but could not detect binding to epithelial cells. In contrast, the intact epithelial layer inhibited CPB penetration into deeper intestinal layers. CPB failed to induce cytopathic effects in cultured polarized porcine intestinal epithelial cells (IPEC-J2) and primary jejunal epithelial cells. C. perfringens type C culture supernatants were toxic for cell cultures. This, however, was not inhibited by CPB neutralization. Our results show that, in the porcine small intestine, CPB primarily targets endothelial cells and does not bind to epithelial cells. An intact intestinal epithelial layer prevents CPB diffusion into underlying tissue and CPB alone does not cause direct damage to intestinal epithelial cells. Additional factors might be involved in the early epithelial damage which is needed for CPB diffusion towards its endothelial targets in the small intestine. PMID:25860161

  14. Natural selection for earlier male arrival to breeding grounds through direct and indirect effects in a migratory songbird.

    PubMed

    Velmala, William; Helle, Samuli; Ahola, Markus P; Klaassen, Marcel; Lehikoinen, Esa; Rainio, Kalle; Sirkiä, Päivi M; Laaksonen, Toni

    2015-03-01

    For migratory birds, the earlier arrival of males to breeding grounds is often expected to have fitness benefits. However, the selection differential on male arrival time has rarely been decomposed into the direct effect of male arrival and potential indirect effects through female traits. We measured the directional selection differential on male arrival time in the pied flycatcher (Ficedula hypoleuca) using data from 6 years and annual number of fledglings as the fitness proxy. Using structural equation modeling, we were able to take into account the temporal structure of the breeding cycle and the hierarchy between the examined traits. We found directional selection differentials for earlier male arrival date and earlier female laying date, as well as strong selection differential for larger clutch size. These selection differentials were due to direct selection only as indirect selection for these traits was nonsignificant. When decomposing the direct selection for earlier male arrival into direct and indirect effects, we discovered that it was almost exclusively due to the direct effect of male arrival date on fitness and not due to its indirect effects via female traits. In other words, we showed for the first time that there is a direct effect of male arrival date on fitness while accounting for those effects that are mediated by effects of the social partner. Our study thus indicates that natural selection directly favored earlier male arrival in this flycatcher population. PMID:25859326

  15. Natural selection for earlier male arrival to breeding grounds through direct and indirect effects in a migratory songbird

    PubMed Central

    Velmala, William; Helle, Samuli; Ahola, Markus P; Klaassen, Marcel; Lehikoinen, Esa; Rainio, Kalle; Sirkiä, Päivi M; Laaksonen, Toni

    2015-01-01

    For migratory birds, the earlier arrival of males to breeding grounds is often expected to have fitness benefits. However, the selection differential on male arrival time has rarely been decomposed into the direct effect of male arrival and potential indirect effects through female traits. We measured the directional selection differential on male arrival time in the pied flycatcher (Ficedula hypoleuca) using data from 6 years and annual number of fledglings as the fitness proxy. Using structural equation modeling, we were able to take into account the temporal structure of the breeding cycle and the hierarchy between the examined traits. We found directional selection differentials for earlier male arrival date and earlier female laying date, as well as strong selection differential for larger clutch size. These selection differentials were due to direct selection only as indirect selection for these traits was nonsignificant. When decomposing the direct selection for earlier male arrival into direct and indirect effects, we discovered that it was almost exclusively due to the direct effect of male arrival date on fitness and not due to its indirect effects via female traits. In other words, we showed for the first time that there is a direct effect of male arrival date on fitness while accounting for those effects that are mediated by effects of the social partner. Our study thus indicates that natural selection directly favored earlier male arrival in this flycatcher population. PMID:25859326

  16. High performance organic field-effect transistors with ultra-thin HfO2 gate insulator deposited directly onto the organic semiconductor

    NASA Astrophysics Data System (ADS)

    Ono, S.; Häusermann, R.; Chiba, D.; Shimamura, K.; Ono, T.; Batlogg, B.

    2014-01-01

    We have produced stable organic field-effect transistors (OFETs) with an ultra-thin HfO2 gate insulator deposited directly on top of rubrene single crystals by atomic layer deposition (ALD). We find that ALD is a gentle deposition process to grow thin films without damaging rubrene single crystals, as results these devices have a negligibly small threshold voltage and are very stable against gate-bias-stress, and the mobility exceeds 1 cm2/V s. Moreover, the devices show very little degradation even when kept in air for more than 2 months. These results demonstrate thin HfO2 layers deposited by ALD to be well suited as high capacitance gate dielectrics in OFETs operating at small gate voltage. In addition, the dielectric layer acts as an effective passivation layer to protect the organic semiconductor.

  17. High performance organic field-effect transistors with ultra-thin HfO{sub 2} gate insulator deposited directly onto the organic semiconductor

    SciTech Connect

    Ono, S.; Häusermann, R.; Laboratory for Solid State Physics, ETH Zurich, Zurich 8093 ; Chiba, D.; PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 322-0012; Department of Applied Physics, University of Tokyo, Tokyo 113-8656 ; Shimamura, K.; Ono, T.; Batlogg, B.

    2014-01-06

    We have produced stable organic field-effect transistors (OFETs) with an ultra-thin HfO{sub 2} gate insulator deposited directly on top of rubrene single crystals by atomic layer deposition (ALD). We find that ALD is a gentle deposition process to grow thin films without damaging rubrene single crystals, as results these devices have a negligibly small threshold voltage and are very stable against gate-bias-stress, and the mobility exceeds 1 cm{sup 2}/V s. Moreover, the devices show very little degradation even when kept in air for more than 2 months. These results demonstrate thin HfO{sub 2} layers deposited by ALD to be well suited as high capacitance gate dielectrics in OFETs operating at small gate voltage. In addition, the dielectric layer acts as an effective passivation layer to protect the organic semiconductor.

  18. Predicting right-wing authoritarianism via personality and dangerous world beliefs: direct, indirect, and interactive effects.

    PubMed

    Dallago, Francesca; Mirisola, Alberto; Roccato, Michele

    2012-01-01

    In an Italian sample (N = 483, 78.23% women, mean age = 27.61 years old), we used structural equation modeling with latent variables and interactions to analyze the direct, indirect, and interactive effects exerted on right-wing authoritarianism by the Big Five factors of personality and by dangerous world beliefs. Openness, Neuroticism, and Conscientiousness exerted direct effects on right-wing authoritarianism; the first two relationships were partially mediated by dangerous world beliefs. Most importantly, the relationship between dangerous world beliefs and right-wing authoritarianism was moderated by Openness: dangerous world beliefs significantly influenced right-wing authoritarianism solely for participants high in Openness. Limitations and possible developments of this research are discussed. PMID:22308764

  19. Effect of Bed Characters on the Direct Synthesis of Dimethyldichlorosilane in Fluidized Bed Reactor

    PubMed Central

    Zhang, Pan; Duan, Ji H.; Chen, Guang H.; Wang, Wei W.

    2015-01-01

    This paper presents the numerical investigation of the effects of the general bed characteristics such as superficial gas velocities, bed temperature, bed heights and particle size, on the direct synthesis in a 3D fluidized bed reactor. A 3D model for the gas flow, heat transfer, and mass transfer was coupled to the direct synthesis reaction mechanism verified in the literature. The model was verified by comparing the simulated reaction rate and dimethyldichlorosilane (M2) selectivity with the experimental data in the open literature and real production data. Computed results indicate that superficial gas velocities, bed temperature, bed heights, and particle size have vital effect on the reaction rates and/or M2 selectivity. PMID:25742729

  20. Effect of Bed Characters on the Direct Synthesis of Dimethyldichlorosilane in Fluidized Bed Reactor

    NASA Astrophysics Data System (ADS)

    Zhang, Pan; Duan, Ji H.; Chen, Guang H.; Wang, Wei W.

    2015-03-01

    This paper presents the numerical investigation of the effects of the general bed characteristics such as superficial gas velocities, bed temperature, bed heights and particle size, on the direct synthesis in a 3D fluidized bed reactor. A 3D model for the gas flow, heat transfer, and mass transfer was coupled to the direct synthesis reaction mechanism verified in the literature. The model was verified by comparing the simulated reaction rate and dimethyldichlorosilane (M2) selectivity with the experimental data in the open literature and real production data. Computed results indicate that superficial gas velocities, bed temperature, bed heights, and particle size have vital effect on the reaction rates and/or M2 selectivity.