Science.gov

Sample records for dimensionless numbers expressed

  1. Dimensionless Numbers Expressed in Terms of Common CVD Process Parameters

    NASA Technical Reports Server (NTRS)

    Kuczmarski, Maria A.

    1999-01-01

    A variety of dimensionless numbers related to momentum and heat transfer are useful in Chemical Vapor Deposition (CVD) analysis. These numbers are not traditionally calculated by directly using reactor operating parameters, such as temperature and pressure. In this paper, these numbers have been expressed in a form that explicitly shows their dependence upon the carrier gas, reactor geometry, and reactor operation conditions. These expressions were derived for both monatomic and diatomic gases using estimation techniques for viscosity, thermal conductivity, and heat capacity. Values calculated from these expressions compared well to previously published values. These expressions provide a relatively quick method for predicting changes in the flow patterns resulting from changes in the reactor operating conditions.

  2. Walking dynamic similarity induced by a combination of Froude and Strouhal dimensionless numbers: Modela-w.

    PubMed

    Villeger, David; Costes, Antony; Watier, Bruno; Moretto, Pierre

    2015-01-01

    The aim of this study was to assess the accuracy of a new dimensionless number associating Froude (Nfr) and Strouhal (Str) called Modela-w to induce walking dynamic similarity among humans of different sizes. Nineteen subjects walked in three experimental conditions: (i) constant speed, (ii) similar speed (Nfr) and (iii) similar speed and similar step frequency (Modela-w). The dynamic similarity was evaluated from scale factors computed with anthropometric, temporal, kinematic and kinetic data and from the decrease of the variability of the parameters expressed in their dimensionless form. Over a total of 36 dynamic parameters, dynamic similarity from scale factors was met for 11 (mean r = 0.51), 22 (mean r = 0.52) and 30 (mean r = 0.69) parameters in the first, the second and the third experimental conditions, respectively. Modela-w also reduced the variability of the dimensionless preceding parameters compared to the other experimental conditions. This study shows that the combination of Nfr and Str called Modela-w ensures dynamic similarity between different-sized subjects and allows scientists to impose similar experimental conditions removing all anthropometric effects.

  3. Modela-r as a Froude and Strouhal dimensionless numbers combination for dynamic similarity in running.

    PubMed

    Villeger, David; Costes, Antony; Watier, Bruno; Moretto, Pierre

    2014-12-18

    The aim of this study was to test the hypothesis that running at fixed fractions of Froude (Nfr) and Strouhal (Str) dimensionless numbers combinations induce dynamic similarity between humans of different sizes. Nineteen subjects ran in three experimental conditions, (i) constant speed, (ii) similar speed (Nfr) and (iii) similar speed and similar step frequency (Nfr and Str combination). In addition to anthropometric data, temporal, kinematic and kinetic parameters were assessed at each stage to measure dynamic similarity informed by dimensional scale factors and by the decrease of dimensionless mechanical parameter variability. Over a total of 54 dynamic parameters, dynamic similarity from scale factors was met for 16 (mean r=0.51), 32 (mean r=0.49) and 52 (mean r=0.60) parameters in the first, the second and the third experimental conditions, respectively. The variability of the dimensionless preceding parameters was lower in the third condition than in the others. This study shows that the combination of Nfr and Str, computed from the dimensionless energy ratio at the center of gravity (Modela-r) ensures dynamic similarity between different-sized subjects. The relevance of using similar experimental conditions to compare mechanical dimensionless parameters is also proved and will highlight the study of running techniques, or equipment, and will allow the identification of abnormal and pathogenic running patterns. Modela-r may be adapted to study other abilities requiring bounces in human or animal locomotion or to conduct investigations in comparative biomechanics.

  4. A new dimensionless number highlighted from mechanical energy exchange during running.

    PubMed

    Delattre, Nicolas; Moretto, Pierre

    2008-09-18

    This study aimed to highlight a new dimensionless number from mechanical energy transfer occurring at the centre of gravity (Cg) during running. We built two different-sized spring-mass models (SMM #1 and SMM #2). SMM #1 was built from the previously published data, and SMM #2 was built to be dynamically similar to SMM #1. The potential gravitational energy (E(P)), kinetic energy (E(K)), and potential elastic energy (E(E)) were taken into account to test our hypothesis. For both SMM #1 and SMM #2, N(Mo-Dela)=(E(P)+E(K))/E(E) reached the same mean value and was constant (4.1+/-0.7) between 30% and 70% of contact time. Values of N(Mo-Dela) obtained out of this time interval were due to the absence of E(E) at initial and final times of the simulation. This phenomenon does not occur during in vivo running because a leg muscle's pre-activation enables potential elastic energy storage prior to ground contact. Our findings also revealed that two different-sized spring-mass models bouncing with equal N(Mo-Dela) values moved in a dynamically similar fashion. N(Mo-Dela), which can be expressed by the combination of Strouhal and Froude numbers, could be of great interest in order to study animal and human locomotion under Earth's gravity or to induce dynamic similarity between different-sized individuals during bouncing gaits.

  5. The landscape Reynolds number and other dimensionless measures of Earth surface processes

    NASA Astrophysics Data System (ADS)

    Haff, P. K.

    2007-11-01

    An analogy between turbulent fluid systems and landscape drainage systems [Parker, G., Haff, P.K., Murray, A.B., 2001, EOS, Transactions of the American Geophysical Union, 82, pp. F564.] is suggested by the observation that transport in both systems can be approximated by diffusion with size-proportional effective diffusivities, with a cross-over at small scales to Fickian diffusion. The "landscape" Reynolds number of a typical fluvial landscape is estimated to be of order Re L ˜ 10 6 to 10 9, these large values reflecting the relative efficiency of fluvial transport compared to creep. Re L is the ratio of the large-scale effective diffusivity of rivers to the small-scale diffusivity of creep processes on hillslopes. The spatial dependence of the effective diffusivity produces rivers with logarithmic long-profiles, similar to the profiles of many rivers in nature, and analogous to the logarithmic dependence of mean fluid velocity on distance from a wall in turbulent flow. The landscape example suggests how other generalized "Reynolds numbers" can be constructed as ratios of large-scale to small-scale diffusivities to measure the efficiencies of complex processes that affect the surface. As an example, the global airline transportation network is estimated to have an efficacy relative to that of direct human mechanisms for transport of similar goods and materials of about 10 8 as measured by a corresponding "technology" Reynolds number. The appearance of such large dimensionless numbers, pertaining to the consequences of human invention and design, reflects the emergence of the technosphere as an increasingly efficient overlay on the historical domain of biology and surficial geology.

  6. Dimensionless cosmology

    NASA Astrophysics Data System (ADS)

    Narimani, Ali; Moss, Adam; Scott, Douglas

    2012-10-01

    Although it is well known that any consideration of the variations of fundamental constants should be restricted to their dimensionless combinations, the literature on variations of the gravitational constant G is entirely dimensionfull. To illustrate applications of this to cosmology, we explicitly give a dimensionless version of the parameters of the standard cosmological model, and describe the physics of both Big Bang Nucleosynthesis and recombination in a dimensionless manner. Rigorously determining how to talk about the model in a way which avoids physical dimensions is a requirement for proceeding with a calculation to constrain time-varying fundamental constants. The issue that appears to have been missed in many studies is that in cosmology the strength of gravity is bound up in the cosmological equations, and the epoch at which we live is a crucial part of the model. We argue that it is useful to consider the hypothetical situation of communicating with another civilization (with entirely different units), comparing only dimensionless constants, in order to decide if we live in a Universe governed by precisely the same physical laws. In this thought experiment, we would also have to compare epochs, which can be defined by giving the value of any one of the evolving cosmological parameters. By setting things up carefully in this way one can avoid inconsistent results when considering variable constants, caused by effectively fixing more than one parameter today. We show examples of this effect by considering microwave background anisotropies, being careful to maintain dimensionlessness throughout. We present Fisher matrix calculations to estimate how well the fine structure constants for electromagnetism and gravity can be determined with future microwave background experiments. We highlight how one can be misled by simply adding G to the usual cosmological parameter set.

  7. Flow paths and chemical reactivity of CO2 in carbonates using Mercury-Intrusion Capillary Pressure data and dimensionless numbers

    NASA Astrophysics Data System (ADS)

    Vialle, S.; Dvorkin, J. P.; Mavko, G. M.

    2012-12-01

    Experiments performed earlier by Vialle and Vanorio (2011) [1] have showed that the injection of CO2-rich water (pH=3.2) in various calcite limestones lead to heterogeneous dissolution of the pore structure, inducing secondary porosity and changing the rock stiffness. The presence of oil in the pore space affects the magnitude of these changes by lowering the reactive surface area. We present here a semi-quantitative analysis at the mesoscale to investigate how different initial pore microgeometries and heterogeneities in pore microgeometry affect the fluid-rock interactions. In particular, we aim at quantitatively explaining (1) why, in clean samples, higher-porosity micrite with rounded grains appears to be more affected by dissolution than tight micrite and spar cement and (2) why, for the same number of pore volumes of fluid injected, the magnitude of the changes in porosity (and subsequently elastic properties) differs among the studied rock samples. Rock microgeometry is studied by classical rock-physics methods, He-pycnometry and Mercury-Intrusion Capillary Pressure (MICP) tests, as well as by Scanning Electron Microscopy (SEM) imaging. Experiments were performed on subsamples (~0.5cm3) extracted from core plugs (~12cm3): two Fontainebleau sandstones, to serve as benchmarks, and two calcite carbonates from two different geological formations. In order to relate pore microgeometry to flow paths and chemical reactivity of CO2 in carbonate rocks, we chose to work at a scale that lies between the pore scale and the core scale. The method consists of physically subdividing the core plugs under examination into subsets based on the pore-throat sizes; these subsets correspond to three types of microstructure: "macropores", "microporous rounded micrite", and "spar cement"/"tight micrite". The dimensionless Péclet (Pe) and Damkhöler (Da) numbers, defined as the ratio between the advection rate and the diffusion rate, and as the ratio between the reaction rate and

  8. Advanced control of liquid water region in diffusion media of polymer electrolyte fuel cells through a dimensionless number

    NASA Astrophysics Data System (ADS)

    Wang, Yun; Chen, Ken S.

    2016-05-01

    In the present work, a three-dimension (3-D) model of polymer electrolyte fuel cells (PEFCs) is employed to investigate the complex, non-isothermal, two-phase flow in the gas diffusion layer (GDL). Phase change in gas flow channels is explained, and a simplified approach accounting for phase change is incorporated into the fuel cell model. It is found that the liquid water contours in the GDL are similar along flow channels when the channels are subject to two-phase flow. Analysis is performed on a dimensionless parameter Da0 introduced in our previous paper [Y. Wang and K. S. Chen, Chemical Engineering Science 66 (2011) 3557-3567] and the parameter is further evaluated in a realistic fuel cell. We found that the GDL's liquid water (or liquid-free) region is determined by the Da0 number which lumps several parameters, including the thermal conductivity and operating temperature. By adjusting these factors, a liquid-free GDL zone can be created even though the channel stream is two-phase flow. Such a liquid-free zone is adjacent to the two-phase region, benefiting local water management, namely avoiding both severe flooding and dryness.

  9. An empirical/theoretical model with dimensionless numbers to predict the performance of electrodialysis systems on the basis of operating conditions.

    PubMed

    Karimi, Leila; Ghassemi, Abbas

    2016-07-01

    Among the different technologies developed for desalination, the electrodialysis/electrodialysis reversal (ED/EDR) process is one of the most promising for treating brackish water with low salinity when there is high risk of scaling. Multiple researchers have investigated ED/EDR to optimize the process, determine the effects of operating parameters, and develop theoretical/empirical models. Previously published empirical/theoretical models have evaluated the effect of the hydraulic conditions of the ED/EDR on the limiting current density using dimensionless numbers. The reason for previous studies' emphasis on limiting current density is twofold: 1) to maximize ion removal, most ED/EDR systems are operated close to limiting current conditions if there is not a scaling potential in the concentrate chamber due to a high concentration of less-soluble salts; and 2) for modeling the ED/EDR system with dimensionless numbers, it is more accurate and convenient to use limiting current density, where the boundary layer's characteristics are known at constant electrical conditions. To improve knowledge of ED/EDR systems, ED/EDR models should be also developed for the Ohmic region, where operation reduces energy consumption, facilitates targeted ion removal, and prolongs membrane life compared to limiting current conditions. In this paper, theoretical/empirical models were developed for ED/EDR performance in a wide range of operating conditions. The presented ion removal and selectivity models were developed for the removal of monovalent ions and divalent ions utilizing the dominant dimensionless numbers obtained from laboratory scale electrodialysis experiments. At any system scale, these models can predict ED/EDR performance in terms of monovalent and divalent ion removal.

  10. An empirical/theoretical model with dimensionless numbers to predict the performance of electrodialysis systems on the basis of operating conditions.

    PubMed

    Karimi, Leila; Ghassemi, Abbas

    2016-07-01

    Among the different technologies developed for desalination, the electrodialysis/electrodialysis reversal (ED/EDR) process is one of the most promising for treating brackish water with low salinity when there is high risk of scaling. Multiple researchers have investigated ED/EDR to optimize the process, determine the effects of operating parameters, and develop theoretical/empirical models. Previously published empirical/theoretical models have evaluated the effect of the hydraulic conditions of the ED/EDR on the limiting current density using dimensionless numbers. The reason for previous studies' emphasis on limiting current density is twofold: 1) to maximize ion removal, most ED/EDR systems are operated close to limiting current conditions if there is not a scaling potential in the concentrate chamber due to a high concentration of less-soluble salts; and 2) for modeling the ED/EDR system with dimensionless numbers, it is more accurate and convenient to use limiting current density, where the boundary layer's characteristics are known at constant electrical conditions. To improve knowledge of ED/EDR systems, ED/EDR models should be also developed for the Ohmic region, where operation reduces energy consumption, facilitates targeted ion removal, and prolongs membrane life compared to limiting current conditions. In this paper, theoretical/empirical models were developed for ED/EDR performance in a wide range of operating conditions. The presented ion removal and selectivity models were developed for the removal of monovalent ions and divalent ions utilizing the dominant dimensionless numbers obtained from laboratory scale electrodialysis experiments. At any system scale, these models can predict ED/EDR performance in terms of monovalent and divalent ion removal. PMID:27108213

  11. Dimensionless thermodynamics: a new paradigm for liquid state properties.

    PubMed

    Sanchez, Isaac C

    2014-08-01

    Equations of state in the van der Waals genre suggest that saturated liquids should adhere to the following corresponding states principle (CSP): saturated liquids at the same reduced density (ρR = ρ/ρc) have comparable dimensionless thermodynamic properties. This CSP is shown to be applicable to a variety of thermodynamic properties that include entropy of vaporization, cohesive energy density, thermal expansion coefficient, isothermal compressibility, thermal pressure coefficient, compressibility factor, temperature coefficient of the vapor pressure, heat capacity difference, and surface tension. For two classes of liquids, all properties rendered dimensionless by the proper choice of scaling variables superpose to form "master curves" that illustrate the CSP. Using scaled particle theory, an improved van der Waals model is developed whose results are compared with existing experimental thermodynamic data in dimensionless form. Properly expressing thermodynamic properties in dimensionless form acts to consolidate and harmonize liquid state properties.

  12. Revealing a quantum feature of dimensionless uncertainty in linear and quadratic potentials by changing potential intervals

    NASA Astrophysics Data System (ADS)

    Kheiri, R.

    2016-09-01

    As an undergraduate exercise, in an article (2012 Am. J. Phys. 80 780–14), quantum and classical uncertainties for dimensionless variables of position and momentum were evaluated in three potentials: infinite well, bouncing ball, and harmonic oscillator. While original quantum uncertainty products depend on {{\\hslash }} and the number of states (n), a dimensionless approach makes the comparison between quantum uncertainty and classical dispersion possible by excluding {{\\hslash }}. But the question is whether the uncertainty still remains dependent on quantum number n. In the above-mentioned article, there lies this contrast; on the one hand, the dimensionless quantum uncertainty of the potential box approaches classical dispersion only in the limit of large quantum numbers (n\\to ∞ )—consistent with the correspondence principle. On the other hand, similar evaluations for bouncing ball and harmonic oscillator potentials are equal to their classical counterparts independent of n. This equality may hide the quantum feature of low energy levels. In the current study, we change the potential intervals in order to make them symmetric for the linear potential and non-symmetric for the quadratic potential. As a result, it is shown in this paper that the dimensionless quantum uncertainty of these potentials in the new potential intervals is expressed in terms of quantum number n. In other words, the uncertainty requires the correspondence principle in order to approach the classical limit. Therefore, it can be concluded that the dimensionless analysis, as a useful pedagogical method, does not take away the quantum feature of the n-dependence of quantum uncertainty in general. Moreover, our numerical calculations include the higher powers of the position for the potentials.

  13. Revealing a quantum feature of dimensionless uncertainty in linear and quadratic potentials by changing potential intervals

    NASA Astrophysics Data System (ADS)

    Kheiri, R.

    2016-09-01

    As an undergraduate exercise, in an article (2012 Am. J. Phys. 80 780-14), quantum and classical uncertainties for dimensionless variables of position and momentum were evaluated in three potentials: infinite well, bouncing ball, and harmonic oscillator. While original quantum uncertainty products depend on {{\\hslash }} and the number of states (n), a dimensionless approach makes the comparison between quantum uncertainty and classical dispersion possible by excluding {{\\hslash }}. But the question is whether the uncertainty still remains dependent on quantum number n. In the above-mentioned article, there lies this contrast; on the one hand, the dimensionless quantum uncertainty of the potential box approaches classical dispersion only in the limit of large quantum numbers (n\\to ∞ )—consistent with the correspondence principle. On the other hand, similar evaluations for bouncing ball and harmonic oscillator potentials are equal to their classical counterparts independent of n. This equality may hide the quantum feature of low energy levels. In the current study, we change the potential intervals in order to make them symmetric for the linear potential and non-symmetric for the quadratic potential. As a result, it is shown in this paper that the dimensionless quantum uncertainty of these potentials in the new potential intervals is expressed in terms of quantum number n. In other words, the uncertainty requires the correspondence principle in order to approach the classical limit. Therefore, it can be concluded that the dimensionless analysis, as a useful pedagogical method, does not take away the quantum feature of the n-dependence of quantum uncertainty in general. Moreover, our numerical calculations include the higher powers of the position for the potentials.

  14. Critical Dimensionless Shields Values for Bankfull Flow

    NASA Astrophysics Data System (ADS)

    Bunte, K.; Abt, S. R.; Swingle, K. W.

    2009-12-01

    The critical dimensionless shear stress τ*c (depicted in the Shields curve as a function of the Reynolds particle number Rep) quantifies the slope - flow depth product at which particles from a relatively well-sorted bed with a mean particle size Dm visually start to move. Contrary to many applications of the Shields curve, τ*c was not designed to predict the bed particle size becoming mobile at bankfull flow. This study sketches a bankfull and a critical bankfull Shields-type curve needed to predict the bankfull mobile particle size. Most studies on bedmaterial entrainment are performed in streams that are wadeable at low flow, but exceed wadeability around bankfull flow. Within the bounds of these stream dimensions, the study drafts a relationship of τ*bf versus Rep (bankfull Shields curve) for a sequence of stream types (in sensu Montgomery and Buffington 1997) ranging from steep cobble headwater streams to plane-bed and pool-riffle gravel-beds to low gradient valley streams with sand and silt beds. Probable values of stream gradient, bed D50 size, and a (roughness corrected) hydraulic radius can be assigned to each stream type. The resulting bankfull curve takes values of τ*bf near 10 for silt and 1 for sand-bedded streams, drops to around 0.05 - 0.02 for mobile gravel-bed streams and then increases towards 0.1 and 0.2 for the steepest streams. Transforming τ*bf into the critical bankfull curve τ*cbf from which to predict the bankfull entrainable particle size requires information on the bedload particle size that becomes mobile at bankfull flow. To estimate τ*cbf over a variety of coarse gravel- and cobble-bed mountain streams, the authors used flow competence curves measured with bedload traps at 10 sites. Bedload traps have a 0.3 m by 0.2 m opening, and 1-1.6 m long trailing net with a 4 mm mesh; mounting traps onto ground plates anchored to the stream bottom permits 1-hr sampling times; 4 to 6 traps are typically installed across the stream width

  15. Dimensionless Equation of State to Predict Microemulsion Phase Behavior.

    PubMed

    Ghosh, Soumyadeep; Johns, Russell T

    2016-09-01

    Prediction of microemulsion phase behavior for changing state variables is critical to formulation design of surfactant-oil-brine (SOB) systems. SOB systems find applications in various chemical and petroleum processes, including enhanced oil recovery. A dimensional equation-of-state (EoS) was recently presented by Ghosh and Johns1 that relied on estimation of the surfactant tail length and surface area. We give an algorithm for flash calculations for estimation of three-phase Winsor regions that is more robust, simpler, and noniterative by making the equations dimensionless so that estimates of tail length and surface area are no longer needed. We predict phase behavior as a function temperature, pressure, volume, salinity, oil type, oil-water ratio, and surfactant/alcohol concentration. The dimensionless EoS is based on coupling the HLD-NAC (Hydrophilic Lipophilic Difference-Net Average Curvature) equations with new relationships between optimum salinity and solubility. An updated HLD expression that includes pressure is also used to complete the state description. A significant advantage of the dimensionless form of the EoS over the dimensional version is that salinity scans are tuned based only on one parameter, the interfacial volume ratio. Further, stability conditions are developed in a simplified way to predict whether an overall compositions lies within the single, two-, or three-phase regions. Important new microemulsion relationships are also found, the most important of which is that optimum solubilization ratio is equal to the harmonic mean of the oil and water solubilization ratios in the type III region. Thus, only one experimental measurement is needed in the three-phase zone to estimate the optimum solubilization ratio, a result which can aid experimental design and improve estimates of optimum from noisy data. Predictions with changing state variables are illustrated by comparison to experimental data using standard diagrams including a new type

  16. Dimensionless Equation of State to Predict Microemulsion Phase Behavior.

    PubMed

    Ghosh, Soumyadeep; Johns, Russell T

    2016-09-01

    Prediction of microemulsion phase behavior for changing state variables is critical to formulation design of surfactant-oil-brine (SOB) systems. SOB systems find applications in various chemical and petroleum processes, including enhanced oil recovery. A dimensional equation-of-state (EoS) was recently presented by Ghosh and Johns1 that relied on estimation of the surfactant tail length and surface area. We give an algorithm for flash calculations for estimation of three-phase Winsor regions that is more robust, simpler, and noniterative by making the equations dimensionless so that estimates of tail length and surface area are no longer needed. We predict phase behavior as a function temperature, pressure, volume, salinity, oil type, oil-water ratio, and surfactant/alcohol concentration. The dimensionless EoS is based on coupling the HLD-NAC (Hydrophilic Lipophilic Difference-Net Average Curvature) equations with new relationships between optimum salinity and solubility. An updated HLD expression that includes pressure is also used to complete the state description. A significant advantage of the dimensionless form of the EoS over the dimensional version is that salinity scans are tuned based only on one parameter, the interfacial volume ratio. Further, stability conditions are developed in a simplified way to predict whether an overall compositions lies within the single, two-, or three-phase regions. Important new microemulsion relationships are also found, the most important of which is that optimum solubilization ratio is equal to the harmonic mean of the oil and water solubilization ratios in the type III region. Thus, only one experimental measurement is needed in the three-phase zone to estimate the optimum solubilization ratio, a result which can aid experimental design and improve estimates of optimum from noisy data. Predictions with changing state variables are illustrated by comparison to experimental data using standard diagrams including a new type

  17. Comment on ‘Dimensionless units in the SI’

    NASA Astrophysics Data System (ADS)

    Leonard, B. P.

    2015-08-01

    In their paper, Mohr and Phillips demonstrate that the SI’s representation of ‘plane angle’ as dimensionless rather than as an independent dimensional quantity continues to create confusion. The authors also address perceived problems in terminology regarding numbers of items, such as discrete events or particles. However, their general philosophy of equating the dimensionlessnumber of items’ to ‘(number of items)  ×  (item name)’ leads to false conclusions, such as that the hertz is equal to 2π radians per second, and therefore not a coherent SI unit. In attempting to specify kinds of entities, the authors introduce descriptive labels into their supposed ‘units,’ resulting in confusion between number of entities and amount of substance. And, in discussing the mole and related fundamental constants, they incorrectly portray the Avogadro constant as a conversion factor, identically equal to 1, thereby corrupting the relationships between the Boltzmann constant and the universal gas constant, and between the elementary charge and the Faraday constant. In my comment, I explain and correct these and related errors.

  18. Similarity Theory and Dimensionless Numbers in Heat Transfer

    ERIC Educational Resources Information Center

    Marin, E.; Calderon, A.; Delgado-Vasallo, O.

    2009-01-01

    We present basic concepts underlying the so-called similarity theory that in our opinion should be explained in basic undergraduate general physics courses when dealing with heat transport problems, in particular with those involving natural or free convection. A simple example is described that can be useful in showing a criterion for neglecting…

  19. Stagnation region gas film cooling: Effects of dimensionless coolant temperature

    NASA Technical Reports Server (NTRS)

    Bonnice, M. A.; Lecuyer, M. R.

    1983-01-01

    An experimental investigation was conducted to mode the film cooling performance for a turbine vane leading edge using the stagnation region of a cylinder in cross flow. Experiments were conducted with a single row of spanwise angled (25 deg) coolant holes for a range of the coolant blowing ratio and dimensionless coolant temperature with free stream-to-wall temperature ratio approximately 1.7 and Re sub D = 90000. the cylindrical test surface was instrumented with miniature heat flux gages and wall thermocouples to determine the percentage reduction in the Stanton number as a function of the distance downstream from injection (x/d sub 0) and the location between adjacent holes (z/S). Data from local heat flux measurements are presented for injection from a single row located at 5 deg, 22.9 deg, 40.8 deg, from stagnation using a hole spacing ratio of S/d = 5. The film coolant was injected with T sub c T sub w with a dimensionless coolant temperature in the range 1.18 or equal to theta sub c or equal to 1.56. The data for local Stanton Number Reduction (SNR) showed a significant increase in SNR as theta sub c was increased above 1.0.

  20. Regulatory element copy number differences shape primate expression profiles

    PubMed Central

    Iskow, Rebecca C.; Gokcumen, Omer; Abyzov, Alexej; Malukiewicz, Joanna; Zhu, Qihui; Sukumar, Ann T.; Pai, Athma A.; Mills, Ryan E.; Habegger, Lukas; Cusanovich, Darren A.; Rubel, Meagan A.; Perry, George H.; Gerstein, Mark; Stone, Anne C.; Gilad, Yoav; Lee, Charles

    2012-01-01

    Gene expression differences are shaped by selective pressures and contribute to phenotypic differences between species. We identified 964 copy number differences (CNDs) of conserved sequences across three primate species and examined their potential effects on gene expression profiles. Samples with copy number different genes had significantly different expression than samples with neutral copy number. Genes encoding regulatory molecules differed in copy number and were associated with significant expression differences. Additionally, we identified 127 CNDs that were processed pseudogenes and some of which were expressed. Furthermore, there were copy number-different regulatory regions such as ultraconserved elements and long intergenic noncoding RNAs with the potential to affect expression. We postulate that CNDs of these conserved sequences fine-tune developmental pathways by altering the levels of RNA. PMID:22797897

  1. Dimensionless constants, cosmology, and other dark matters

    SciTech Connect

    Tegmark, Max; Aguirre, Anthony; Rees, Martin J.; Wilczek, Frank

    2006-01-15

    We identify 31 dimensionless physical constants required by particle physics and cosmology, and emphasize that both microphysical constraints and selection effects might help elucidate their origin. Axion cosmology provides an instructive example, in which these two kinds of arguments must both be taken into account, and work well together. If a Peccei-Quinn phase transition occurred before or during inflation, then the axion dark matter density will vary from place to place with a probability distribution. By calculating the net dark matter halo formation rate as a function of all four relevant cosmological parameters and assessing other constraints, we find that this probability distribution, computed at stable solar systems, is arguably peaked near the observed dark matter density. If cosmologically relevant weakly interacting massive particle (WIMP) dark matter is discovered, then one naturally expects comparable densities of WIMPs and axions, making it important to follow up with precision measurements to determine whether WIMPs account for all of the dark matter or merely part of it.

  2. Flexibility, stroke, and dimensionless parameters: the importance of telling the whole story for swimming micro-organisms in complex fluids

    NASA Astrophysics Data System (ADS)

    Thomases, Becca; Guy, Robert

    2015-11-01

    The question of how fluid elasticity affects the swimming performance of micro-organisms is complicated and has been the subject of many recent experimental and theoretical studies. The Deborah number, De = λω , is typically used to characterize the strength of the fluid elasticity in these studies, and for swimmers is expressed as the product of the elastic relaxation time and the frequency of the swimmer stroke. In simulations of undulatory flexible swimmers in an Oldroyd-B-type fluid, we find that varying the frequency of the stroke and varying the relaxation time separately results in a significantly different dependence of swimming speed for the same De . Thus the elastic effects on swimming cannot be characterized by a single dimensionless number. The Weissenberg number, defined as the product of elastic relaxation time and characteristic strain rate (Wi = λγ˙), is another dimensionless parameter useful for describing complex fluids. For a fixed swimmer frequency, varying the relaxation time will also vary the Weissenberg number. We conjecture that the different behavior is a consequence of a Weissenberg-number transition in the fluid, which additionally depends on the amplitude of the swimmer stroke.

  3. Dimensionless parameters to summarize the influence of microbial growth and inhibition on the bioremediation of groundwater contaminants.

    PubMed

    Mohamed, M; Hatfield, K

    2011-09-01

    Monod expressions are preferred over zero- and first-order decay expressions in modeling contaminants biotransformation in groundwater because they better represent complex conditions. However, the wide-range of values reported for Monod parameters suggests each case-study is unique. Such uniqueness restricts the usefulness of modeling, complicates an interpretation of natural attenuation and limits the utility of a bioattenuation assessment to a small number of similar cases. In this paper, four Monod-based dimensionless parameters are developed that summarize the effects of microbial growth and inhibition on groundwater contaminants. The four parameters represent the normalized effective microbial growth rate (η), the normalized critical contaminant/substrate concentration (S*), the critical contaminant/substrate inhibition factor (N), and the bioremediation efficacy (η*). These parameters enable contaminated site managers to assess natural attenuation or augmented bioremediation at multiple sites and then draw comparisons between disparate remediation activities, sites and target contaminants. Simulations results are presented that reveal the sensitivity of these dimensionless parameters to Monod parameters and varying electron donor/acceptor loads. These simulations also show the efficacy of attenuation (η*) varying over space and time. Results suggest electron donor/acceptor amendments maintained at relative concentrations S* between 0.5 and 1.5 produce the highest remediation efficiencies. Implementation of the developed parameters in a case study proves their usefulness.

  4. A universal feature in the optical absorption spectrum associated with hydrogenated amorphous silicon: A dimensionless joint density of states analysis

    NASA Astrophysics Data System (ADS)

    Thevaril, Jasmin J.; O'Leary, Stephen K.

    2016-10-01

    Using a dimensionless joint density of states formalism for the quantitative characterization of the optical response associated with hydrogenated amorphous silicon, a critical comparative analysis of a large number of different optical absorption data sets is considered. When these data sets are cast into this dimensionless framework, we observe a trend that is almost completely coincident for all of the data sets considered. This suggests that there is a universal feature associated with the optical absorption spectrum of hydrogenated amorphous silicon.

  5. A dimensionless parameter for classifying hemodynamics in intracranial

    NASA Astrophysics Data System (ADS)

    Asgharzadeh, Hafez; Borazjani, Iman

    2015-11-01

    Rupture of an intracranial aneurysm (IA) is a disease with high rates of mortality. Given the risk associated with the aneurysm surgery, quantifying the likelihood of aneurysm rupture is essential. There are many risk factors that could be implicated in the rupture of an aneurysm. However, the most important factors correlated to the IA rupture are hemodynamic factors such as wall shear stress (WSS) and oscillatory shear index (OSI) which are affected by the IA flows. Here, we carry out three-dimensional high resolution simulations on representative IA models with simple geometries to test a dimensionless number (first proposed by Le et al., ASME J Biomech Eng, 2010), denoted as An number, to classify the flow mode. An number is defined as the ratio of the time takes the parent artery flow transports across the IA neck to the time required for vortex ring formation. Based on the definition, the flow mode is vortex if An>1 and it is cavity if An<1. We show that the specific definition of Le et al. works for sidewall but needs to be modified for bifurcation aneurysms. In addition, we show that this classification works on three-dimensional geometries reconstructed from three-dimensional rotational angiography of human subjects. Furthermore, we verify the correlation of IA flow mode and WSS/OSI on the human subject IA. This work was supported partly by the NIH grant R03EB014860, and the computational resources were partly provided by CCR at UB. We thank Prof. Hui Meng and Dr. Jianping Xiang for providing us the database of aneurysms and helpful discussions.

  6. How the Number of Alleles Influences Gene Expression

    NASA Astrophysics Data System (ADS)

    Hat, Beata; Paszek, Pawel; Kimmel, Marek; Piechor, Kazimierz; Lipniacki, Tomasz

    2007-07-01

    The higher organisms, eukaryotes, are diploid and most of their genes have two homological copies (alleles). However, the number of alleles in a cell is not constant. In the S phase of the cell cycle all the genome is duplicated and then in the G2 phase and mitosis, which together last for several hours, most of the genes have four copies instead of two. Cancer development is, in many cases, associated with a change in allele number. Several genetic diseases are caused by haploinsufficiency: Lack of one of the alleles or its improper functioning. In the paper we consider the stochastic expression of a gene having a variable number of copies. We applied our previously developed method in which the reaction channels are split into slow (connected with change of gene state) and fast (connected with mRNA/protein synthesis/decay), the later being approximated by deterministic reaction rate equations. As a result we represent gene expression as a piecewise deterministic time-continuous Markov process, which is further related with a system of partial differential hyperbolic equations for probability density functions (pdfs) of protein distribution. The stationary pdfs are calculated analytically for haploidal gene or numerically for diploidal and tetraploidal ones. We distinguished nine classes of simultaneous activation of haploid, diploid and tetraploid genes. This allows for analysis of potential consequences of gene duplication or allele loss. We show that when gene activity is autoregulated by a positive feedback, the change in number of gene alleles may have dramatic consequences for its regulation and may not be compensated by the change of efficiency of mRNA synthesis per allele.

  7. A dimensionless model of impact piezoelectric energy harvesting with dissipation

    NASA Astrophysics Data System (ADS)

    Fu, Xinlei; Liao, Wei-Hsin

    2016-04-01

    Impact excitation is common in the environment. Impact piezoelectric energy harvesting could realize frequency up-conversion. However, the dissipation mechanism in impact piezoelectric energy harvesting has not been investigated so far. There is no comprehensive model to be able to analyze the impact piezoelectric energy harvesting thoroughly. This paper is aimed to develop a generalized model that considers dissipation mechanism of impact piezoelectric energy harvesting. In this electromechanical model, Hertzian contact theory and impact dissipation mechanism are identified as constitutive mechanisms. The impact force is compared and the energy distribution is analyzed so that input energy corresponds to impact dissipated energy, structural damping dissipated energy and harvested electrical energy. We then nondimensionalize the developed model and define five dimensionless parameters with attributed physical meanings, including dimensionless parameters of impact dissipation, mass ratio, structural damping, electromechanical coupling, and electrical load. We conclude it is more accurate to consider impact dissipation mechanism to predict impact force and harvested energy. The guideline for improving harvested energy based on parametric studies of dimensionless model is to increase mass ratio, to minimize structural damping, to maximize electromechanical coupling, to use optimal load resistance for impedance matching, and to choose proper impact velocity .

  8. Estimating Mass of Inflatable Aerodynamic Decelerators Using Dimensionless Parameters

    NASA Technical Reports Server (NTRS)

    Samareh, Jamshid A.

    2011-01-01

    This paper describes a technique for estimating mass for inflatable aerodynamic decelerators. The technique uses dimensional analysis to identify a set of dimensionless parameters for inflation pressure, mass of inflation gas, and mass of flexible material. The dimensionless parameters enable scaling of an inflatable concept with geometry parameters (e.g., diameter), environmental conditions (e.g., dynamic pressure), inflation gas properties (e.g., molecular mass), and mass growth allowance. This technique is applicable for attached (e.g., tension cone, hypercone, and stacked toroid) and trailing inflatable aerodynamic decelerators. The technique uses simple engineering approximations that were developed by NASA in the 1960s and 1970s, as well as some recent important developments. The NASA Mars Entry and Descent Landing System Analysis (EDL-SA) project used this technique to estimate the masses of the inflatable concepts that were used in the analysis. The EDL-SA results compared well with two independent sets of high-fidelity finite element analyses.

  9. Multi-machine comparison of drift fluid dimensionless parameters

    NASA Astrophysics Data System (ADS)

    Militello, F.; Fundamenski, W.

    2011-09-01

    The behaviour of the turbulence in magnetic fusion plasmas is discussed in the framework of dimensional analysis. Three main dimensionless parameters are identified, which directly affect the adiabatic response of the plasma and hence control the electron response. They were originally introduced by Scott (1997 Plasma Phys. Control. Fusion 39 1635) and Rogers and Drake (1997 Phys. Rev. Lett. 79 229), and represent the effect of the electromagnetic induction, collisions and electron inertia. The dimensionless parameters are then evaluated at different radial positions in four existing divertor machines (ALCATOR C-MOD, ASDEX-Upgrade, JET and MAST) and in three future experiments (MAST-Upgrade, ITER and DEMO). Clear multi-machine trends, suggesting a quasi-universal behaviour of the plasma, are identified and discussed. Exploiting this quasi-universality, useful insight into the physics of the machines is obtained without complex calculations or expensive numerical simulations. In particular, the trends show a clear separation of the plasma in four distinct regions: core, edge, scrape-off layer and divertor, each of them characterized by a different set of parameters which, in turn, lead to significant variation of the dominant physical mechanisms across the machine.

  10. Dimensionless Analysis and Numerical Modeling of Rebalancing Phenomena During Levitation

    NASA Astrophysics Data System (ADS)

    Gao, Lei; Shi, Zhe; Li, Donghui; McLean, Alexander; Chattopadhyay, Kinnor

    2016-06-01

    Electromagnetic levitation (EML) has proved to be a powerful tool for research activities in areas pertaining to materials physics and engineering. The customized EML setups in various fields, ranging from solidification to nanomaterial manufacturing, require the designing of stable levitation systems. Since the elevated droplet is opaque, the most effective way to research on EML is mathematical modeling. In the present study, a 3D model was built to investigate the rebalancing phenomenon causing instabilities during droplet melting. A mathematical model modified based on Hooke's law (spring) was proposed to describe the levitation system. This was combined with dimensionless analysis to investigate the generation of levitation forces as it will significantly affect the behavior of the spring model.

  11. Dimensionless size scaling of intrinsic rotation in DIII-D

    NASA Astrophysics Data System (ADS)

    deGrassie, J. S.; Solomon, W. M.; Rice, J. E.; Noterdaeme, J.-M.

    2016-08-01

    A dimensionless empirical scaling for intrinsic toroidal rotation is given: MA˜βNρ* , where MA is the toroidal velocity divided by the Alfvén velocity, βN is the usual normalized β value, and ρ* is the ion gyroradius divided by the minor radius. This scaling describes well experimental data from DIII-D and also some published data from C-Mod and JET. The velocity used in this scaling is in an outer location in minor radius, outside of the interior core and inside of the large gradient edge region in H-mode conditions. This scaling establishes the basic magnitude of the intrinsic toroidal rotation, and its relation to the rich variety of rotation profiles that can be realized for intrinsic conditions is discussed. This scaling has some similarities to existing dimensioned scalings, both the Rice scaling [J. E. Rice et al., Phys. Plasmas 7, 1825 (2000)] and the scaling of Parra et al. [Phys. Rev. Lett. 108, 095001 (2012)]. These relationships are described.

  12. The impact of human copy number variation on gene expression

    PubMed Central

    Gamazon, Eric R.

    2015-01-01

    Recent years have witnessed a flurry of important technological and methodological developments in the discovery and analysis of copy number variations (CNVs), which are increasingly enabling the systematic evaluation of their impact on a broad range of phenotypes from molecular-level (intermediate) traits to higher-order clinical phenotypes. Like single nucleotide variants in the human genome, CNVs have been linked to complex traits in humans, including disease and drug response. These recent developments underscore the importance of incorporating complex forms of genetic variation into disease mapping studies and promise to transform our understanding of genome function and the genetic basis of disease. Here we review some of the findings that have emerged from transcriptome studies of CNVs facilitated by the rapid advances in -omics technologies and corresponding methodologies. PMID:25922366

  13. Correctly Expressing Atomic Weights

    NASA Astrophysics Data System (ADS)

    Paolini, Moreno; Cercignani, Giovanni; Bauer, Carlo

    2000-11-01

    Very often, atomic or molecular weights are expressed as dimensionless quantities, but although the historical importance of their definition as "pure numbers" is acknowledged, it is inconsistent with experimental formulas and with the theory of measure in general. Here, we propose on the basis of clear-cut formulas that, contrary to customary statements, atomic and molecular weights should be expressed as dimensional quantities (masses) in which the Dalton (= 1.663 x 10-24 g) is taken as the unit.

  14. The Erosive Potential of the Horseshoe Vortex System and its Relation to Dimensional and Dimensionless Parameters

    NASA Astrophysics Data System (ADS)

    Al-Saffar, M. S. A.

    2015-12-01

    The turbulent flow of air or water around an object can result in scour and erosion of the underlying substrate. The fluid mechanics of this process is explained the dynamics of the Horseshoe Vortex (HV) system that forms as a result of the flow separation induced by the object. In this work, the characteristics of the HV system in front of a wall-mounted circular cylinder have been studied experimentally to improve understanding of these complex dynamics as a function of relevant dimensionless parameters. The flow velocity field within the plane of symmetry, upstream of the cylinder, was measured using Particle Image Velocimetry (PIV) and vorticity fields were obtained from this. A range of natural flow conditions were obtained when Froude number (Fr) was varied from subcritical to supercritical conditions over the range 0.015 to 2.46, and the influence of other governing parameters such as the cylinder-based and depth-based Reynolds numbers was also investigated systematically. The results of a Quadrant analysis show the variation in turbulent stress contributions from positions underneath and upstream of the HV system. Proper Orthogonal Decomposition (POD) was used to elucidate the size and nature of the observed flow structure. The results show that the flow depth (h) has the primary control on the location of the HV system, while the magnitude of the peak wall stresses is controlled by cylinder diameter, Fr, and flow depth. That the controls include a mixture of dimensionless and dimensional factors highlights some of the complexity of translating laboratory results into practical recommendations for the study of natural systems, or for effective modelling with eddy-resolving numeric.

  15. Glucocorticoids decrease astrocyte numbers by reducing glucocorticoid receptor expression in vitro and in vivo.

    PubMed

    Unemura, Kazuhiro; Kume, Toshiaki; Kondo, Minami; Maeda, Yuki; Izumi, Yasuhiko; Akaike, Akinori

    2012-01-01

    Glucocorticoids are stress hormones released from the adrenal cortex and their concentration is controlled by the hypothalamic-pituitary-adrenal axis. In this study, we investigated the effect of glucocorticoids on the number of astrocytes and glucocorticoid receptor (GR) expression in vitro and in vivo. Proliferation of cultured astrocytes was reduced following treatment with corticosterone and dexamethasone for 72 h. Corticosterone and dexamethasone also reduced GR expression in astrocytes. RU486, a GR antagonist, inhibited the reduction in both astrocyte proliferation and GR expression. Furthermore, GR knockdown by siRNA inhibited astrocyte proliferation. We also examined the effect of excessive glucocorticoid release on GR expression and the number of astrocytes in vivo by administering adrenocorticotropic hormone to rats for 14 days. GR expression was reduced in the prefrontal cortex and hippocampus and the number of astrocytes was reduced in the frontal cortex. Overall, our results suggest that glucocorticoids decrease the number of astrocytes by reducing GR expression.

  16. Application of symbolic regression to the derivation of scaling laws for tokamak energy confinement time in terms of dimensionless quantities

    NASA Astrophysics Data System (ADS)

    Murari, A.; Peluso, E.; Lungaroni, M.; Gelfusa, M.; Gaudio, P.

    2016-02-01

    In many scientific applications, it is important to investigate how certain properties scale with the parameters of the systems. The experimental studies of scalings have traditionally been addressed with log regression, which limits the results to power laws and to theoretical and not data-driven dimensionless quantities. This has also been the case in nuclear fusion, in which the scaling of the energy confinement time is a crucial aspect in understanding the physics of transport and in the design of future devices. Traditionally two main assumptions are at the basis of the most widely accepted empirical scaling laws for the confinement time: (a) the dimensionless variables used are the ones derived from the symmetries of the Vlasov equation; (b) the final scalings have the mathematical form of power laws. In this paper, it is shown how symbolic regression (SR), implemented with genetic programming (GP) techniques, can be used to test these hypotheses. Neither assumption is confirmed by the available data of the multi-machine International Tokamak Physics Activity (ITPA) of validated tokamak discharges. The statistically soundest expressions are not power laws and cannot be formulated in terms of the traditional dimensionless quantities. The consequences of the data-driven scaling laws obtained are both practical and theoretical: the confinement time for the ITER can be significantly shorter than foreseen by power laws and different dimensionless variables should be considered for theoretical investigations. On the other hand, higher quality databases should be built to reduce the uncertainties in the extrapolations. It is also worth emphasising that the proposed methodology is fully general and therefore can be applied to any field of science.

  17. Testing the mean magnetization approximation, dimensionless and scaling numbers in magnetorheology.

    PubMed

    Ruiz-López, José Antonio; Fernández-Toledano, Juan Carlos; Hidalgo-Alvarez, Roque; de Vicente, Juan

    2016-02-01

    The mean magnetization (MM) approximation is undoubtedly the most widely used approximation in magnetorheology both from theoretical and simulation perspectives. According to this, spherical magnetizable particles under field can be replaced by effective dipole moments m placed at their center with strength m = V(p)⟨M(p)⟩. Here V(p) and ⟨M(p)⟩ are the volume and mean (average) magnetization of the particles, respectively. In spite of being extensively used, there is not a mathematical justification to do so in most cases. In this manuscript, we test this approximation using experiments, theories and simulations, for a wide range of magnetic field strengths and particle loadings, in both conventional magnetorheological fluids (CMRFs) and inverse ferrofluids (IFFs). Results demonstrate that the MM approximation is applicable in IFFs for a very wide range of field strengths (up to external fields of 265 kA m(-1)) and particle loadings (up to 20 vol%). For CMRFs, the MM approximation is only applicable in two particular circumstances; in magnetic saturation or in infinite dilution. PMID:26647041

  18. Effects of genome-wide copy number variation on expression in mammalian cells

    PubMed Central

    2011-01-01

    Background There is only a limited understanding of the relation between copy number and expression for mammalian genes. We fine mapped cis and trans regulatory loci due to copy number change for essentially all genes using a human-hamster radiation hybrid (RH) panel. These loci are called copy number expression quantitative trait loci (ceQTLs). Results Unexpected findings from a previous study of a mouse-hamster RH panel were replicated. These findings included decreased expression as a result of increased copy number for 30% of genes and an attenuated relationship between expression and copy number on the X chromosome suggesting an Xist independent form of dosage compensation. In a separate glioblastoma dataset, we found conservation of genes in which dosage was negatively correlated with gene expression. These genes were enriched in signaling and receptor activities. The observation of attenuated X-linked gene expression in response to increased gene number was also replicated in the glioblastoma dataset. Of 523 gene deserts of size > 600 kb in the human RH panel, 325 contained trans ceQTLs with -log10 P > 4.1. Recently discovered genes, ultra conserved regions, noncoding RNAs and microRNAs explained only a small fraction of the results, suggesting a substantial portion of gene deserts harbor as yet unidentified functional elements. Conclusion Radiation hybrids are a useful tool for high resolution mapping of cis and trans loci capable of affecting gene expression due to copy number change. Analysis of two independent radiation hybrid panels show agreement in their findings and may serve as a discovery source for novel regulatory loci in noncoding regions of the genome. PMID:22085887

  19. Somatic Copy Number Alterations at Oncogenic Loci Show Diverse Correlations with Gene Expression

    NASA Astrophysics Data System (ADS)

    Roszik, Jason; Wu, Chang-Jiun; Siroy, Alan E.; Lazar, Alexander J.; Davies, Michael A.; Woodman, Scott E.; Kwong, Lawrence N.

    2016-01-01

    Somatic copy number alterations (SCNAs) affecting oncogenic drivers have a firmly established role in promoting cancer. However, no agreed-upon standard exists for calling locus-specific amplifications and deletions in each patient sample. Here, we report the correlative analysis of copy number amplitude and length with gene expression across 6,109 samples from The Cancer Genome Atlas (TCGA) dataset across 16 cancer types. Using specificity, sensitivity, and precision-based scores, we assigned optimized amplitude and length cutoffs for nine recurrent SCNAs affecting known oncogenic drivers, using mRNA expression as a functional readout. These cutoffs captured the majority of SCNA-driven, highly-expression-altered samples. The majority of oncogenes required only amplitude cutoffs, as high amplitude samples were almost invariably focal; however, CDKN2A and PTEN uniquely required both amplitude and length cutoffs as primary predictors. For PTEN, these extended to downstream AKT activation. In contrast, SCNA genes located peri-telomerically or in fragile sites showed poor expression-copy number correlations. Overall, our analyses identify optimized amplitude and length cutoffs as efficient predictors of gene expression changes for specific oncogenic SCNAs, yet warn against one-size-fits-all interpretations across all loci. Our results have implications for cancer data analyses and the clinic, where copy number and mutation data are increasingly used to personalize cancer therapy.

  20. Somatic Copy Number Alterations at Oncogenic Loci Show Diverse Correlations with Gene Expression

    PubMed Central

    Roszik, Jason; Wu, Chang-Jiun; Siroy, Alan E.; Lazar, Alexander J.; Davies, Michael A; Woodman, Scott E; Kwong, Lawrence N

    2016-01-01

    Somatic copy number alterations (SCNAs) affecting oncogenic drivers have a firmly established role in promoting cancer. However, no agreed-upon standard exists for calling locus-specific amplifications and deletions in each patient sample. Here, we report the correlative analysis of copy number amplitude and length with gene expression across 6,109 samples from The Cancer Genome Atlas (TCGA) dataset across 16 cancer types. Using specificity, sensitivity, and precision-based scores, we assigned optimized amplitude and length cutoffs for nine recurrent SCNAs affecting known oncogenic drivers, using mRNA expression as a functional readout. These cutoffs captured the majority of SCNA-driven, highly-expression-altered samples. The majority of oncogenes required only amplitude cutoffs, as high amplitude samples were almost invariably focal; however, CDKN2A and PTEN uniquely required both amplitude and length cutoffs as primary predictors. For PTEN, these extended to downstream AKT activation. In contrast, SCNA genes located peri-telomerically or in fragile sites showed poor expression-copy number correlations. Overall, our analyses identify optimized amplitude and length cutoffs as efficient predictors of gene expression changes for specific oncogenic SCNAs, yet warn against one-size-fits-all interpretations across all loci. Our results have implications for cancer data analyses and the clinic, where copy number and mutation data are increasingly used to personalize cancer therapy. PMID:26787600

  1. Tumor transcriptome sequencing reveals allelic expression imbalances associated with copy number alterations.

    PubMed

    Tuch, Brian B; Laborde, Rebecca R; Xu, Xing; Gu, Jian; Chung, Christina B; Monighetti, Cinna K; Stanley, Sarah J; Olsen, Kerry D; Kasperbauer, Jan L; Moore, Eric J; Broomer, Adam J; Tan, Ruoying; Brzoska, Pius M; Muller, Matthew W; Siddiqui, Asim S; Asmann, Yan W; Sun, Yongming; Kuersten, Scott; Barker, Melissa A; De La Vega, Francisco M; Smith, David I

    2010-02-19

    Due to growing throughput and shrinking cost, massively parallel sequencing is rapidly becoming an attractive alternative to microarrays for the genome-wide study of gene expression and copy number alterations in primary tumors. The sequencing of transcripts (RNA-Seq) should offer several advantages over microarray-based methods, including the ability to detect somatic mutations and accurately measure allele-specific expression. To investigate these advantages we have applied a novel, strand-specific RNA-Seq method to tumors and matched normal tissue from three patients with oral squamous cell carcinomas. Additionally, to better understand the genomic determinants of the gene expression changes observed, we have sequenced the tumor and normal genomes of one of these patients. We demonstrate here that our RNA-Seq method accurately measures allelic imbalance and that measurement on the genome-wide scale yields novel insights into cancer etiology. As expected, the set of genes differentially expressed in the tumors is enriched for cell adhesion and differentiation functions, but, unexpectedly, the set of allelically imbalanced genes is also enriched for these same cancer-related functions. By comparing the transcriptomic perturbations observed in one patient to his underlying normal and tumor genomes, we find that allelic imbalance in the tumor is associated with copy number mutations and that copy number mutations are, in turn, strongly associated with changes in transcript abundance. These results support a model in which allele-specific deletions and duplications drive allele-specific changes in gene expression in the developing tumor.

  2. Common Spatial Organization of Number and Emotional Expression: A Mental Magnitude Line

    ERIC Educational Resources Information Center

    Holmes, Kevin J.; Lourenco, Stella F.

    2011-01-01

    Converging behavioral and neural evidence suggests that numerical representations are mentally organized in left-to-right orientation. Here we show that this format of spatial organization extends to emotional expression. In Experiment 1, right-side responses became increasingly faster as number (represented by Arabic numerals) or happiness…

  3. Effect of passage number on cellular response DNA-damaging agents: cell survival and gene expression

    SciTech Connect

    Chang-Liu, Chin-Mei; Wolschak, G.E.

    1996-03-01

    The effect of different passage numbers on plating efficiency, doubling time, cell growth, and radiation sensitivity was assessed in Syrian hamster embryo (SHE) cells. Changes in gene expression after UV or {gamma}-ray irradiation at different passage numbers were also examined. The SHE cells were maintained in culture medium for up to 64 passages. Cells were exposed to {sup 60}Co {gamma} rays or 254-m UV radiation. Differential display of cDNAs and Northern blots were used for the study of gene expression. With increasing passage number, SHE cells demonstrated decreased doubling time, increased plating efficiency, and a decreased yield in the number of cells per plate. Between passages 41 and 48 a ``crisis`` period was evident during which time cell growth in high serum (20%) was no longer optimal, and serum concentrations were reduced (to 10%) to maintain cell growth. Sensitivity to ionizing radiation was no different between early- and intermediate-passage cells. However, after UV exposure at low passages (passage 3), confluent cells were more sensitive to the killing effects of UV than were log-phase cells. At intermediate passages (passages 43, 48), confluent cells were slightly more radioresistant- than were log-phase cells. By passage 64, however, both confluent and log-phase cells showed similar patterns of UV sensitivity. Expression of {gamma}-actin, PCNA, and p53 transcripts did not change following UV exposure. p53 mRNA was induced following {gamma}-ray exposure of the intermediate (passage 45) epithelial cells. Differential display, however, revealed changes in expression of several transcripts following exposure to ionizing and ultraviolet radiations. The observed differences in radiation sensitivity associated with increasing passage number may be influenced by radiation-induced gene expression. We are conducting experiments to identify these genes.

  4. Hybrid piezoelectric-inductive flow energy harvesting and dimensionless electroaeroelastic analysis for scaling

    NASA Astrophysics Data System (ADS)

    Dias, J. A. C.; De Marqui, C.; Erturk, A.

    2013-01-01

    Piezoelectric and electromagnetic transduction techniques have peculiar advantages to leverage in the growing field of flow energy harvesting from aeroelastic vibrations. This letter presents the concept of hybrid piezoelectric-inductive power generation with electroaeroelastic modeling and simulations. Dimensionless analysis of the coupled system dynamics is indispensable to proper geometric scaling and optimization of aeroelastic energy harvesters. The governing electroaeroelastic equations are given in dimensionless form, and the effects of aeroelastic and electrical properties are investigated in detail toward understanding the dependence of the cut-in speed (flutter speed) and the maximum power output of the harvester on the system parameters.

  5. Integration of transcript expression, copy number and LOH analysis of infiltrating ductal carcinoma of the breast

    PubMed Central

    2010-01-01

    Background A major challenge in the interpretation of genomic profiling data generated from breast cancer samples is the identification of driver genes as distinct from bystander genes which do not impact tumorigenesis. One way to assess the relative importance of alterations in the transcriptome profile is to combine parallel analyses that assess changes in the copy number alterations (CNAs). This integrated analysis permits the identification of genes with altered expression that map within specific chromosomal regions which demonstrate copy number alterations, providing a mechanistic approach to identify the 'driver genes'. Methods We have performed whole genome analysis of CNAs using the Affymetrix 250K Mapping array on 22 infiltrating ductal carcinoma samples (IDCs). Analysis of transcript expression alterations was performed using the Affymetrix U133 Plus2.0 array on 16 IDC samples. Fourteen IDC samples were analyzed using both platforms and the data integrated. We also incorporated data from loss of heterozygosity (LOH) analysis to identify genes showing altered expression in LOH regions. Results Common chromosome gains and amplifications were identified at 1q21.3, 6p21.3, 7p11.2-p12.1, 8q21.11 and 8q24.3. A novel amplicon was identified at 5p15.33. Frequent losses were found at 1p36.22, 8q23.3, 11p13, 11q23, and 22q13. Over 130 genes were identified with concurrent increases or decreases in expression that mapped to these regions of copy number alterations. LOH analysis revealed three tumors with whole chromosome or p arm allelic loss of chromosome 17. Genes were identified that mapped to copy neutral LOH regions. LOH with accompanying copy loss was detected on Xp24 and Xp25 and genes mapping to these regions with decreased expression were identified. Gene expression data highlighted the PPARα/RXRα Activation Pathway as down-regulated in the tumor samples. Conclusion We have demonstrated the utility of the application of integrated analysis using high

  6. Algebraic expression of the IBM3 hamiltonian in terms of various quantum numbers

    NASA Astrophysics Data System (ADS)

    Hasegawa, M.

    1991-04-01

    The properties of the IBM3 hamiltonian are algebraically studied. The IBM3 hamiltonian determined microscopically has as characteristic that the isospin T, rmrather than the spin J, is essential to classifying the energy spectra. The T-dependence of the two-body boson interactions is expressed in terms of the Casimir operators or quantum numbers of various groups. This algebraic approach makes preparations for phenomenological understanding of light nuclei with definite isospin.

  7. Melanosome-autonomous regulation of size and number: the OA1 receptor sustains PMEL expression.

    PubMed

    Falletta, Paola; Bagnato, Paola; Bono, Maria; Monticone, Massimiliano; Schiaffino, Maria Vittoria; Bennett, Dorothy C; Goding, Colin R; Tacchetti, Carlo; Valetti, Caterina

    2014-07-01

    Little is known as to how cells ensure that organelle size and number are coordinated to correctly couple organelle biogenesis to the demands of proliferation or differentiation. OA1 is a melanosome-associated G-protein-coupled receptor involved in melanosome biogenesis during melanocyte differentiation. Cells lacking OA1 contain fewer, but larger, mature melanosomes. Here, we show that OA1 loss of function reduces both the basal expression and the α-melanocyte-stimulating hormone/cAMP-dependent induction of the microphthalmia-associated transcription factor (MITF), the master regulator of melanocyte differentiation. In turn, this leads to a significant reduction in expression of PMEL, a major melanosomal structural protein, but does not affect tyrosinase and melanin levels. In line with its pivotal role in sensing melanosome maturation, OA1 expression rescues melanosome biogenesis, activates MITF expression and thereby coordinates melanosome size and number, providing a quality control mechanism for the organelle in which resides. Thus, resident sensor receptors can activate a transcriptional cascade to specifically promote organelle biogenesis. PMID:24650003

  8. From DNA Copy Number to Gene Expression: Local aberrations, Trisomies and Monosomies

    NASA Astrophysics Data System (ADS)

    Shay, Tal

    The goal of my PhD research was to study the effect of DNA copy number changes on gene expression. DNA copy number aberrations may be local, encompassing several genes, or on the level of an entire chromosome, such as trisomy and monosomy. The main dataset I studied was of Glioblastoma, obtained in the framework of a collaboration, but I worked also with public datasets of cancer and Down's Syndrome. The molecular basis of expression changes in Glioblastoma. Glioblastoma is the most common and aggressive type of primary brain tumors in adults. In collaboration with Prof. Hegi (CHUV, Switzerland), we analyzed a rich Glioblastoma dataset including clinical information, DNA copy number (array CGH) and expression profiles. We explored the correlation between DNA copy number and gene expression at the level of chromosomal arms and local genomic aberrations. We detected known amplification and over expression of oncogenes, as well as deletion and down-regulation of tumor suppressor genes. We exploited that information to map alterations of pathways that are known to be disrupted in Glioblastoma, and tried to characterize samples that have no known alteration in any of the studied pathways. Identifying local DNA aberrations of biological significance. Many types of tumors exhibit chromosomal losses or gains and local amplifications and deletions. A region that is aberrant in many tumors, or whose copy number change is stronger, is more likely to be clinically relevant, and not just a by-product of genetic instability. We developed a novel method that defines and prioritizes aberrations by formalizing these intuitions. The method scores each aberration by the fraction of patients harboring it, its length and its amplitude, and assesses the significance of the score by comparing it to a null distribution obtained by permutations. This approach detects genetic locations that are significantly aberrant, generating a 'genomic aberration profile' for each sample. The 'genomic

  9. Clinical Omics Analysis of Colorectal Cancer Incorporating Copy Number Aberrations and Gene Expression Data

    PubMed Central

    Yoshida, Tsuyoshi; Kobayashi, Takumi; Itoda, Masaya; Muto, Taika; Miyaguchi, Ken; Mogushi, Kaoru; Shoji, Satoshi; Shimokawa, Kazuro; Iida, Satoru; Uetake, Hiroyuki; Ishikawa, Toshiaki; Sugihara, Kenichi; Mizushima, Hiroshi; Tanaka, Hiroshi

    2010-01-01

    Background: Colorectal cancer (CRC) is one of the most frequently occurring cancers in Japan, and thus a wide range of methods have been deployed to study the molecular mechanisms of CRC. In this study, we performed a comprehensive analysis of CRC, incorporating copy number aberration (CRC) and gene expression data. For the last four years, we have been collecting data from CRC cases and organizing the information as an “omics” study by integrating many kinds of analysis into a single comprehensive investigation. In our previous studies, we had experienced difficulty in finding genes related to CRC, as we observed higher noise levels in the expression data than in the data for other cancers. Because chromosomal aberrations are often observed in CRC, here, we have performed a combination of CNA analysis and expression analysis in order to identify some new genes responsible for CRC. This study was performed as part of the Clinical Omics Database Project at Tokyo Medical and Dental University. The purpose of this study was to investigate the mechanism of genetic instability in CRC by this combination of expression analysis and CNA, and to establish a new method for the diagnosis and treatment of CRC. Materials and methods: Comprehensive gene expression analysis was performed on 79 CRC cases using an Affymetrix Gene Chip, and comprehensive CNA analysis was performed using an Affymetrix DNA Sty array. To avoid the contamination of cancer tissue with normal cells, laser micro-dissection was performed before DNA/RNA extraction. Data analysis was performed using original software written in the R language. Result: We observed a high percentage of CNA in colorectal cancer, including copy number gains at 7, 8q, 13 and 20q, and copy number losses at 8p, 17p and 18. Gene expression analysis provided many candidates for CRC-related genes, but their association with CRC did not reach the level of statistical significance. The combination of CNA and gene expression analysis

  10. Influence of gene copy number on self-regulated gene expression.

    PubMed

    Jędrak, Jakub; Ochab-Marcinek, Anna

    2016-11-01

    Using an analytically solvable stochastic model, we study the properties of a simple genetic circuit consisting of multiple copies of a self-regulating gene. We analyse how the variation in gene copy number and the mutations changing the auto-regulation strength affect the steady-state distribution of protein concentration. We predict that one-reporter assay, an experimental method where the extrinsic noise level is inferred from the comparison of expression variance of a single and duplicated reporter gene, may give an incorrect estimation of the extrinsic noise contribution when applied to self-regulating genes. We also show that an imperfect duplication of an auto-activated gene, changing the regulation strength of one of the copies, may lead to a hybrid, binary+graded response of these genes to external signal. The analysis of relative changes in mean gene expression before and after duplication suggests that evolutionary accumulation of gene duplications may, at a given mean burst size, non-trivially depend on the inherent noisiness of a given gene, quantified by the inverse of the maximal mean frequency of bursts. Moreover, we find that the dependence of gene expression noise on gene copy number and auto-regulation strength may qualitatively differ, e.g. in monotonicity, depending on whether the noise is measured by Fano factor or coefficient of variation. Thus, experimentally-based hypotheses linking gene expression noise and evolutionary optimisation in the context of gene copy number variation may be ambiguous as they are dependent on the particular function chosen to quantify noise. PMID:27528448

  11. Lack of CD24 expression in mice reduces the number of leukocytes in the colon.

    PubMed

    Bretz, Niko P; Salnikov, Alexei V; Doberstein, Kai; Garbi, Natalio; Kloess, Volker; Joumaa, Safwan; Naumov, Inna; Boon, Louis; Moldenhauer, Gerhard; Arber, Nadir; Altevogt, Peter

    2014-09-01

    CD24 is an extensively glycosylated membrane protein that is linked to the membrane via a glycosyl-phosphatidylinositol (GPI)-anchor. In mice, CD24 is expressed by hematopoietic and non-hematopoietic cells. CD24-/- mice do not have gross immunological defects, but detailed analysis revealed strongly reduced responses in an experimental autoimmune encephalomyelitis (EAE) model and a massive proliferation of T cells under lymphopenic conditions. It was also demonstrated that preB cells from CD24-/- mice are impaired in α4-integrin-mediated cell binding. Here we report that CD24-/- mice have strongly reduced numbers of leukocytes in the colon compared to wildtype mice. The reduction comprized all subpopulations. Leukocyte counts in spleen, mesenteric lymph nodes or small intestine were not significantly different. We find that beside leukocytes, CD24 is widely expressed in EpCAM+ epithelial and CD31+ endothelial cells of colon and small intestine. However, in CD24-/- mice the number of CD31+ endothelial cells in colons was strongly reduced and the number of epithelial cells was augmented. Leukocyte transfer experiments provided evidence that the CD24 status of recipient mice, rather than of the transferred cells, is crucial for leukocyte recruitment to the colon. We hypothesize that CD24 on colonic epithelial and endothelial cells is required for the retention and positioning of leukocytes most likely by affecting integrin function.

  12. Estimating the number of clusters via system evolution for cluster analysis of gene expression data.

    PubMed

    Wang, Kaijun; Zheng, Jie; Zhang, Junying; Dong, Jiyang

    2009-09-01

    The estimation of the number of clusters (NC) is one of crucial problems in the cluster analysis of gene expression data. Most approaches available give their answers without the intuitive information about separable degrees between clusters. However, this information is useful for understanding cluster structures. To provide this information, we propose system evolution (SE) method to estimate NC based on partitioning around medoids (PAM) clustering algorithm. SE analyzes cluster structures of a dataset from the viewpoint of a pseudothermodynamics system. The system will go to its stable equilibrium state, at which the optimal NC is found, via its partitioning process and merging process. The experimental results on simulated and real gene expression data demonstrate that the SE works well on the data with well-separated clusters and the one with slightly overlapping clusters. PMID:19527960

  13. Generation of Large Numbers of Antigen-Expressing Human Dendritic Cells Using CD14-ML Technology.

    PubMed

    Imamura, Yuya; Haruta, Miwa; Tomita, Yusuke; Matsumura, Keiko; Ikeda, Tokunori; Yuno, Akira; Hirayama, Masatoshi; Nakayama, Hideki; Mizuta, Hiroshi; Nishimura, Yasuharu; Senju, Satoru

    2016-01-01

    We previously reported a method to expand human monocytes through lentivirus-mediated introduction of cMYC and BMI1, and we named the monocyte-derived proliferating cells, CD14-ML. CD14-ML differentiated into functional DC (CD14-ML-DC) upon addition of IL-4, resulting in the generation of a large number of DC. One drawback of this method was the extensive donor-dependent variation in proliferation efficiency. In the current study, we found that introduction of BCL2 or LYL1 along with cMYC and BMI1 was beneficial. Using the improved method, we obtained CD14-ML from all samples, regardless of whether the donors were healthy individuals or cancer patients. In vitro stimulation of peripheral blood T cells with CD14-ML-DC that were loaded with cancer antigen-derived peptides led to the establishment of CD4+ and CD8+ T cell lines that recognized the peptides. Since CD14-ML was propagated for more than 1 month, we could readily conduct genetic modification experiments. To generate CD14-ML-DC that expressed antigenic proteins, we introduced lentiviral antigen-expression vectors and subjected the cells to 2 weeks of culture for drug-selection and expansion. The resulting antigen-expressing CD14-ML-DC successfully induced CD8+ T cell lines that were reactive to CMVpp65 or MART1/MelanA, suggesting an application in vaccination therapy. Thus, this improved method enables the generation of a sufficient number of DC for vaccination therapy from a small amount of peripheral blood from cancer patients. Information on T cell epitopes is not necessary in vaccination with cancer antigen-expressing CD14-ML-DC; therefore, all patients, irrespective of HLA type, will benefit from anti-cancer therapy based on this technology. PMID:27050553

  14. Inference of plasmid-copy-number mean and noise from single-cell gene expression data

    NASA Astrophysics Data System (ADS)

    Ghozzi, Stéphane; Wong Ng, Jérôme; Chatenay, Didier; Robert, Jérôme

    2010-11-01

    Plasmids are extrachromosomal DNA molecules which code for their own replication. We previously reported a setup using genes coding for fluorescent proteins of two colors that allowed us, using a simple model, to extract the plasmid-copy-number noise in a monoclonal population of bacteria [J. Wong Ng , Phys. Rev. E 81, 011909 (2010)10.1103/PhysRevE.81.011909]. Here we present a detailed calculation relating this noise to the measured levels of fluorescence, taking into account all sources of fluorescence fluctuations: not only the fluctuation of gene expression as in the simple model but also the growth and division of bacteria, the nonuniform distribution of their ages, the random partition of proteins at divisions, and the replication and partition of plasmids and chromosome. We show how to use the chromosome as a reference, which helps extracting the plasmid-copy-number noise in a self-consistent manner.

  15. A triangular model of dimensionless runoff producing rainfall hyetographs in Texas

    USGS Publications Warehouse

    Asquith, W.H.; Bumgarner, J.R.; Fahlquist, L.S.

    2003-01-01

    A synthetic triangular hyetograph for a large data base of Texas rainfall and runoff is needed. A hyetograph represents the temporal distribution of rainfall intensity at a point or over a watershed during a storm. Synthetic hyetographs are estimates of the expected time distribution for a design storm and principally are used in small watershed hydraulic structure design. A data base of more than 1,600 observed cumulative hyetographs that produced runoff from 91 small watersheds (generally less than about 50 km2) was used to provide statistical parameters for a simple triangular shaped hyetograph model. The model provides an estimate of the average hyetograph in dimensionless form for storm durations of 0 to 24 hours and 24 to 72 hours. As a result of this study, the authors concluded that the expected dimensionless cumulative hyetographs of 0 to 12 hour and 12 to 24 hour durations were sufficiently similar to be combined with minimal information loss. The analysis also suggests that dimensionless cumulative hyetographs are independent of the frequency level or return period of total storm depth and thus are readily used for many design applications. The two triangular hyetographs presented are intended to enhance small watershed design practice in applicable parts of Texas.

  16. Thyroid status affects number and localization of thyroid hormone receptor expressing mast cells in bone marrow.

    PubMed

    Siebler, T; Robson, H; Bromley, M; Stevens, D A; Shalet, S M; Williams, G R

    2002-01-01

    Thyroid hormone (T(3)) plays a key role in endochondral ossification. The process relies on the coordinated synthesis and degradation of cartilage matrix and is disrupted in juvenile hypothyroidism, leading to abnormal skeletal development. Mast cells synthesize and store matrix-degrading enzymes. We examined whether thyroid status influences skeletal mast cell distribution in growing rats to determine whether they might modulate the actions of T(3) in bone. Tibiae were collected for histological, histochemical, immunohistochemical, and immunofluorescence analysis. Mast cells were increased throughout the bone marrow in hypothyroid rats compared with euthyroid, thyrotoxic, and hypothyroid-thyroxine replaced animals. Large numbers were present in metaphyseal marrow adjacent to the growth plate in hypothyroid animals and cells were distributed evenly throughout the marrow. Very few mast cells were present in metaphyseal marrow in other groups, but their numbers increased with increasing distance from the growth plate. T(3) receptor alpha1 (TRalpha1) was expressed in the nucleus and cytoplasm of skeletal mast cells, whereas TRalpha2 and TRbeta1 were restricted to the cytoplasm. Localization of TRs was not affected by altered thyroid status. Thus, disrupted endochondral ossification in hypothyroidism may be mediated in part by skeletal mast cells, which express TR proteins and may function as T(3) target cells.

  17. A new method for estimating the number of non-differentially expressed genes.

    PubMed

    Wu, J; Liu, C Y; Chen, W T; Ma, W Y; Ding, Y

    2016-01-01

    Control of the false discovery rate is a statistical method that is widely used when identifying differentially expressed genes in high-throughput sequencing assays. It is often calculated using an adaptive linear step-up procedure in which the number of non-differentially expressed genes should be estimated accurately. In this paper, we discuss the estimation of this parameter and point out defects in the original estimation method. We also propose a new estimation method and provide the error estimation. We compared the estimation results from the two methods in a simulation study that produced a mean, standard deviation, range, and root mean square error. The results revealed that there was little difference in the mean between the two methods, but the standard deviation, range, and root mean square error obtained using the new method were much smaller than those produced by the original method, which indicates that the new method is more accurate and robust. Furthermore, we used real microarray data to verify the conclusion. Finally we provide a suggestion when analyzing differentially expressed genes using statistical methods. PMID:27051004

  18. Coelomocyte numbers and expression of HSP70 in wounded sea stars during hypoxia.

    PubMed

    Holm, Kristina; Hernroth, Bodil; Thorndyke, Michael

    2008-11-01

    Hypoxia, mainly caused by eutrophication, is a common and growing problem on marine soft bottoms. Echinoderms are known for their ability to regenerate tissue after wounding but hypoxia has a negative influence on regeneration and also on reproduction in echinoderms. We have investigated the cellular and molecular responses to wounding stress and hypoxia in the sea star Asterias rubens by using the total coelomocyte count (TCC) and the expression of heat shock proteins (HSPs). As early as 1 h after wounding, sea stars under hypoxic conditions show significantly increased TCC and, after 6 h, cell numbers increase approximately two-fold. After a 3-h hypoxia exposure of wounded animals, Western blot analysis reveals highly elevated coelomocyte cytoplasmic HSP70 expression. Non-wounded sea stars exposed to hypoxia and wounded animals kept in normoxia show enhanced HSP70 expression only after 24 h. Immunocytochemical analysis has not demonstrated any translocation of HSP70 from the cytoplasm to the nucleus. We conclude that both wounding and hypoxia elicit a stress response in sea stars and that the combined stress produces synergistic effects that may inhibit the initial processes of wound healing and regeneration.

  19. MYC, FBXW7 and TP53 copy number variation and expression in Gastric Cancer

    PubMed Central

    2013-01-01

    Background MYC deregulation is a common event in gastric carcinogenesis, usually as a consequence of gene amplification, chromosomal translocations, or posttranslational mechanisms. FBXW7 is a p53-controlled tumor-suppressor that plays a role in the regulation of cell cycle exit and reentry via MYC degradation. Methods We evaluated MYC, FBXW7, and TP53 copy number, mRNA levels, and protein expression in gastric cancer and paired non-neoplastic specimens from 33 patients and also in gastric adenocarcinoma cell lines. We also determined the invasion potential of the gastric cancer cell lines. Results MYC amplification was observed in 51.5% of gastric tumor samples. Deletion of one copy of FBXW7 and TP53 was observed in 45.5% and 21.2% of gastric tumors, respectively. MYC mRNA expression was significantly higher in tumors than in non-neoplastic samples. FBXW7 and TP53 mRNA expression was markedly lower in tumors than in paired non-neoplastic specimens. Moreover, deregulated MYC and FBXW7 mRNA expression was associated with the presence of lymph node metastasis and tumor stage III-IV. Additionally, MYC immunostaining was more frequently observed in intestinal-type than diffuse-type gastric cancers and was associated with MYC mRNA expression. In vitro studies showed that increased MYC and reduced FBXW7 expression is associated with a more invasive phenotype in gastric cancer cell lines. This result encouraged us to investigate the activity of the gelatinases MMP-2 and MMP-9 in both cell lines. Both gelatinases are synthesized predominantly by stromal cells rather than cancer cells, and it has been proposed that both contribute to cancer progression. We observed a significant increase in MMP-9 activity in ACP02 compared with ACP03 cells. These results confirmed that ACP02 cells have greater invasion capability than ACP03 cells. Conclusion In conclusion, FBXW7 and MYC mRNA may play a role in aggressive biologic behavior of gastric cancer cells and may be a useful

  20. The absence of numbers to express the amount may affect delay discounting with humans.

    PubMed

    Reyes-Huerta, Hugo E; Dos Santos, Cristiano V

    2016-09-01

    Human delay discounting is usually studied with experimental protocols that use symbols to express delay and amount. In order to further understand discounting, we evaluated whether the absence of numbers to represent reward amounts affects discount rate in general, and whether the magnitude effect is generalized to nonsymbolic situations in particular. In Experiment 1, human participants were exposed to a delay-discounting task in which rewards were presented using dots to represent monetary rewards (nonsymbolic); under this condition the magnitude effect did not occur. Nevertheless, the magnitude effect was observed when equivalent reward amounts were presented using numbers (symbolic). Moreover, in estimation tasks, magnitude increments produced underestimation of large amounts. In Experiment 2, participants were exposed only to the nonsymbolic discounting task and were required to estimate reward amounts in each trial. Consistent with Experiment 1, the absence of numbers representing reward amounts produced similar discount rates of small and large rewards. These results suggest that value of nonsymbolic rewards is a nonlinear function of amount and that value attribution depends on perceived difference between the immediate and the delayed nonsymbolic rewards.

  1. Host genetic variants and gene expression patterns associated with Epstein-Barr virus copy number in lymphoblastoid cell lines.

    PubMed

    Houldcroft, Charlotte J; Petrova, Velislava; Liu, Jimmy Z; Frampton, Dan; Anderson, Carl A; Gall, Astrid; Kellam, Paul

    2014-01-01

    Lymphoblastoid cell lines (LCLs) are commonly used in molecular genetics, supplying DNA for the HapMap and 1000 Genomes Projects, used to test chemotherapeutic agents, and informing the basis of a number of population genetics studies of gene expression. The process of transforming human B cells into LCLs requires the presence of Epstein-Barr virus (EBV), a double-stranded DNA virus which through B-cell immortalisation maintains an episomal virus genome in every cell of an LCL at variable copy numbers. Previous studies have reported that EBV alters host-gene expression and EBV copy number may be under host genetic control. We performed a genome-wide association study of EBV genome copy number in LCLs and found the phenotype to be highly heritable, although no individual SNPs achieved a significant association with EBV copy number. The expression of two host genes (CXCL16 and AGL) was positively correlated and expression of ADARB2 was negatively correlated with EBV copy number in a genotype-independent manner. This study shows an association between EBV copy number and the gene expression profile of LCLs, and suggests that EBV copy number should be considered as a covariate in future studies of host gene expression in LCLs.

  2. Epileptiform stimulus increases Homer 1a expression to modulate synapse number and activity in hippocampal cultures

    PubMed Central

    Li, Yan; Popko, Jonathan; Krogh, Kelly A.

    2013-01-01

    Neurons adapt to seizure activity structurally and functionally to attenuate hyperactive neural circuits. Homer proteins provide a scaffold in the postsynaptic density (PSD) by binding to ligands through an EVH1 domain and to other Homer proteins by a coiled-coil domain. The short Homer isoform 1a (H1a) has a ligand-binding domain but lacks a coiled-coil domain and thus acts in a dominant-negative manner to uncouple Homer scaffolds. Here, we show that treating rat hippocampal cultures with bicuculline and 4-aminopyridine (Bic+4-AP) evoked epileptiform activity and synchronized Ca2+ spiking, measured with whole cell current-clamp and fura-2-based digital imaging; Bic+4-AP increased H1a mRNA through the activation of metabotropic glutamate receptor 5 (mGluR5). Treatment with Bic+4-AP for 4 h attenuated burst firing and induced synapse loss. Synaptic changes were measured using a confocal imaging-based assay that quantified clusters of PSD-95 fused to green fluorescent protein. Treatment with an mGluR5 antagonist blocked H1a expression, synapse loss, and burst attenuation. Overexpression of H1a inhibited burst firing similar to Bic+4-AP treatment. Furthermore, knockdown of H1a using a short hairpin RNA (shRNA) strategy reduced synapse loss and burst attenuation induced by Bic+4-AP treatment. Thus an epileptiform stimulus applied to hippocampal neurons in culture induced burst firing and H1a expression through the activation of mGluR5; a 4-h exposure to this stimulus resulted in synapse loss and burst attenuation. These results suggest that H1a expression functions in a negative-feedback manner to reduce network excitability by regulating the number of synapses. PMID:23274309

  3. Genotyping Single Nucleotide Polymorphisms and Copy Number Variability of the FCGRs Expressed on NK Cells.

    PubMed

    Erbe, Amy K; Wang, Wei; Gallenberger, Mikayla; Hank, Jacquelyn A; Sondel, Paul M

    2016-01-01

    Natural killer (NK) cells are one of the main effector immune cells involved in antibody-dependent cell-mediated cytotoxicity (ADCC). Upon recognition of cell-bound IgG antibodies, which occurs through Fc gamma receptors (FCGRs) expressed on the cell surface of NK cells, NK cells become activated and lyse target tumor or infected cells. The FCGRs, FCGR3A and FCGR2C, expressed on the surface of NK cells have single nucleotide polymorphisms (SNPs) that result in differential activity of NK cells. In addition to SNP genetic variation within each of these genes, the FCGRs are subject to copy number variation (CNV), which leads to variable protein expression levels on the cell surface. Studies have found that FCGR genotype for FCGR3A and FCGR2C is associated with variation in the response to immunotherapy.Due to high sequence homology within FCGR3 and FCGR2 families, there are difficulties associated with genotyping these specific receptors related to cross-amplification of non-targeted FCGRs. To improve specificity for both FCGR3A and FCGR2C, Rnase-H (RH) primers were designed to amplify specifically FCGR3A (while not co-amplifying FCGR3B) and FCGR2C (while not co-amplifying FCGR2B). In addition, fluorescently labeled locked nucleic acid (LNA) probes provide additional precision for determination of the SNPs within both FCGR3A and FCGR2C. For CNV determination, separate fluorescently labeled probes for FCGR3A, and for FCGR2C, can be used with the same RH primers for each gene. These probes can be combined in the same well with control primers/probe for a known diploid gene and used to calculate the copy number of both FCGR3A and FCGR2C. Here we provide new detailed methodology that allows for the specific amplification of these FCGRs in a single PCR reaction, allowing for genotyping of both the SNPs and CNVs using real-time PCR.

  4. Number of X-chromosome genes influences social behavior and vasopressin gene expression in mice.

    PubMed

    Cox, Kimberly H; Quinnies, Kayla M; Eschendroeder, Alex; Didrick, Paula M; Eugster, Erica A; Rissman, Emilie F

    2015-01-01

    Sex differences in behavior are widespread and often caused by hormonal differences between the sexes. In addition to hormones, the composition and numbers of the sex chromosomes also affect a variety of sex differences. In humans, X-chromosome genes are implicated in neurobehavioral disorders (i.e. fragile-X, autism). To investigate the role of X-chromosome genes in social behavior, we used a mouse model that has atypical sex chromosome configurations resembling Turner (45, XO) and Klinefelter syndromes (47, XXY). We examined a number of behaviors in juvenile mice. Mice with only one copy of most X-chromosome genes, regardless of gonadal sex, were less social in dyadic interaction and social preference tasks. In the elevated plus maze, mice with one X-chromosome spent less time in the distal ends of the open arms as compared to mice with two copies of X-chromosome genes. Using qRTPCR, we noted that amygdala from female mice with one X-chromosome had higher expression levels of vasopressin (Avp) as compared to mice in the other groups. Finally, in plasma from girls with Turner syndrome we detected reduced vasopressin (AVP) concentrations as compared to control patients. These novel findings link sex chromosome genes with social behavior via concentrations of AVP in brain, adding to our understanding of sex differences in neurobehavioral disorders.

  5. Dimensionless analysis of valveless pumping in a thick-wall elastic tube: Application to the tubular embryonic heart.

    PubMed

    Kozlovsky, Pavel; Rosenfeld, Moshe; Jaffa, Ariel J; Elad, David

    2015-06-25

    The physical mechanism that drives blood flow in the valveless tubular embryonic heart is still debatable whether it is peristaltic flow or valveless dynamic suction. Previous studies of valveless pumping were concerned with either the role of the excitation parameters or the mechanisms that generate the unidirectional outflow. In this study, a dimensionless one-dimensional (1D) analysis of the valveless pumping due to local excitation at an asymmetric longitudinal location was performed for non-uniform thick-wall elastic tubes, including tubes with local bulging and tapering. A general tube law that accounts for wall thicknesses was implemented for describing the physically realistic dynamics of the tube and the two-step MacCormack algorithm was utilized for the numerical analysis. A comprehensive analysis was conducted to explore the affecting roles of the system (e.g., tube geometry) and the working (e.g., Strouhal number and flow friction parameter) parameters on the net outflow of the pump. The maximal positive net outflow in all the tested cases always occurred when the natural Strouhal number was about π. Flow reversals were observed only for relatively low friction parameters. A local bulging at the site of excitation and thick walls contributed to larger outflows, while tube tapering reduced the net outflow.

  6. Dimensionless, Scale Invariant, Edge Weight Metric for the Study of Complex Structural Networks

    PubMed Central

    Colon-Perez, Luis M.; Spindler, Caitlin; Goicochea, Shelby; Triplett, William; Parekh, Mansi; Montie, Eric; Carney, Paul R.; Price, Catherine; Mareci, Thomas H.

    2015-01-01

    High spatial and angular resolution diffusion weighted imaging (DWI) with network analysis provides a unique framework for the study of brain structure in vivo. DWI-derived brain connectivity patterns are best characterized with graph theory using an edge weight to quantify the strength of white matter connections between gray matter nodes. Here a dimensionless, scale-invariant edge weight is introduced to measure node connectivity. This edge weight metric provides reasonable and consistent values over any size scale (e.g. rodents to humans) used to quantify the strength of connection. Firstly, simulations were used to assess the effects of tractography seed point density and random errors in the estimated fiber orientations; with sufficient signal-to-noise ratio (SNR), edge weight estimates improve as the seed density increases. Secondly to evaluate the application of the edge weight in the human brain, ten repeated measures of DWI in the same healthy human subject were analyzed. Mean edge weight values within the cingulum and corpus callosum were consistent and showed low variability. Thirdly, using excised rat brains to study the effects of spatial resolution, the weight of edges connecting major structures in the temporal lobe were used to characterize connectivity in this local network. The results indicate that with adequate resolution and SNR, connections between network nodes are characterized well by this edge weight metric. Therefore this new dimensionless, scale-invariant edge weight metric provides a robust measure of network connectivity that can be applied in any size regime. PMID:26173147

  7. Introducing economic parameters in industrial flotation dimensionless models used for intra-factory technology transfer

    NASA Astrophysics Data System (ADS)

    Batzias, Dimitris; Ifanti, Konstantina

    2012-12-01

    In this work, intra-factory technology transfer is realized by means of scale-up procedures, including the formation of a representative original set of dimensionless groups, when know-how obtained in the laboratory is transferred progressively (in successive steps) into industrial scale. For saving resources (highly skilled manpower, time, materials, energy) a Knowledge Base (KB) is designed/developed to maintain experience in flotation and select relevant information from other Data/Information/Knowledge Bases. Of significant importance is the introduction of economic parameters referring to investment and operation of the industrial unit, thus taking into account the capital and operating cost of output, respectively. We have proved that this introduction causes several problems since new technological dimensions should be also introduced (so that the economic parameters become meaningful) resulting by dimensional analysis to a new solution set that is incompatible to the original one. We solved this problem by keeping the original set and incorporating into it only the new dimensionless groups (eliminating all additional technological dimensions introduced ad hoc).

  8. A Numerical Investigation to Identify Dimensionless Parameters for Dual-Rotor Horizontal Axis Wind Turbines

    NASA Astrophysics Data System (ADS)

    Slew, K. Lee; Miller, M.; Matida, E.

    2016-09-01

    A numerical study was carried out to identify non-dimensional parameters for dual-rotor horizontal axis wind turbines (DRWTs). Based on some important DRWT parameters such as the rotor speeds, rotor diameters and the distance between the rotors, three dimensionless parameters were derived from the Buckingham Pi theorem. Hypothetical DRWT models were created using geometrically-scaled National Renewable Energy Laboratory (NREL) Phase VI rotor geometry and operating conditions in order to confirm the validity of these parameters. The performance of each turbine was simulated using DR_HAWT, an inhouse prediction tool for single and dual-rotor wind turbines created by the current authors. The variation in normalized output power as a function of the dimensionless parameters suggests that an improved performance of DRWTs can be obtained at lower diameter and gap ratios. The NREL Phase VI rotor equipped with a 5 m geometrically-scaled upwind rotor can generate about 88% of the combined power output of two equivalent single-rotors. In addition, the effect of having an auxiliary upwind rotor reduces the angle of attack along the inboard section of the downwind blade.

  9. Genes and small RNA transcripts exhibit dosage-dependent expression pattern in maize copy-number alterations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copy-number alterations are widespread in animal and plant genomes, but their immediate impact on gene expression is still unclear. In animals, copy-number alterations usually exhibit dosage effects, except for sex chromosomes that tend to be dosage compensated. In plants, genes within small duplica...

  10. Mode tuning of a simplified string instrument using time-dimensionless state-derivative control

    NASA Astrophysics Data System (ADS)

    Benacchio, Simon; Chomette, Baptiste; Mamou-Mani, Adrien; Finel, Victor

    2015-01-01

    In recent years, there has been a growing interest in smart structures, particularly in the field of musical acoustics. Control methods, initially developed to reduce vibration and damage, can be a good way to shift modal parameters of a structure in order to modify its dynamic response. This study focuses on smart musical instruments and aims to modify their radiated sound. This is achieved by controlling the modal parameters of the soundboard of a simplified string instrument. A method combining a pole placement algorithm and a time-dimensionless state-derivative control is used and quickly compared to a usual state control method. Then the effect of the mode tuning on the coupling between the string and the soundboard is experimentally studied. Controlling two vibration modes of the soundboard, its acoustic response and the damping of the third partial of the sound are modified. Finally these effects are listened in the radiated sound.

  11. RESEARCH NOTE FROM COLLABORATION: Dimensionless coupling of bulk scalars at the LHC

    NASA Astrophysics Data System (ADS)

    Beauchemin, P.-H.; Azuelos, G.; Burgess, C. P.

    2004-10-01

    We identify the lowest-dimension interaction which is possible between standard model brane fields and bulk scalars in six dimensions. The lowest-dimension interaction is unique and involves a trilinear coupling between the standard model Higgs boson and the bulk scalar. Because this interaction has a dimensionless coupling, it depends only logarithmically on ultraviolet mass scales and heavy physics need not decouple from it. We compute its influence on Higgs physics at ATLAS and identify how large a coupling can be detected at the LHC. Besides providing a potentially interesting signal in Higgs-boson searches, such couplings provide a major observational constraint on 6D large-extra-dimensional models with scalars in the bulk.

  12. Tightly regulated, high-level expression from controlled copy number vectors based on the replicon of temperate phage N15.

    PubMed

    Mardanov, Andrey V; Strakhova, Taisia S; Smagin, Vladimir A; Ravin, Nikolai V

    2007-06-15

    A new Escherichia coli host/vector system has been developed to allow a dual regulation of both the plasmid copy number and gene expression. The new pN15E vectors are low copy number plasmids based on the replicon of temperate phage N15, comprising the repA replicase gene and cB repressor gene, controlling the plasmid copy number. Regulation of pN15E copy number is achieved through arabinose-inducible expression of phage N15 antirepressor protein, AntA, whose gene was integrated into the chromosome of the host strain under control of the PBAD promoter. The host strain also carried phage N15 partition operon, sop, allowing stable inheritance of pN15E vectors in the absence of selection pressure. In the first vector, pN15E4, the same PBAD promoter controls expression of a cloned gene. The second vector, pN15E6, carries the phage T5 promoter with a double lac operator repression module thus allowing independent regulation of promoter activity and copy number. Using the lacZ gene to monitor expression in these vectors, we show that the ratio of induction/repression can be about 7600-fold for pN15E4 and more than 15,000-fold for pN15E6. The low copy number of these vectors ensures very low basal level of expression allowing cloning genes encoding toxic products that was demonstrated by the stable maintenance of a gene encoding a restriction endonuclease in pN15E4. The tight control of transcription and the potential to regulate gene activities quantitatively over wide ranges will open up new approaches in the study of gene function in vivo and controlled expression of heterologous genes.

  13. Individual and combined effects of DNA methylation and copy number alterations on miRNA expression in breast tumors

    PubMed Central

    2013-01-01

    Background The global effect of copy number and epigenetic alterations on miRNA expression in cancer is poorly understood. In the present study, we integrate genome-wide DNA methylation, copy number and miRNA expression and identify genetic mechanisms underlying miRNA dysregulation in breast cancer. Results We identify 70 miRNAs whose expression was associated with alterations in copy number or methylation, or both. Among these, five miRNA families are represented. Interestingly, the members of these families are encoded on different chromosomes and are complementarily altered by gain or hypomethylation across the patients. In an independent breast cancer cohort of 123 patients, 41 of the 70 miRNAs were confirmed with respect to aberration pattern and association to expression. In vitro functional experiments were performed in breast cancer cell lines with miRNA mimics to evaluate the phenotype of the replicated miRNAs. let-7e-3p, which in tumors is found associated with hypermethylation, is shown to induce apoptosis and reduce cell viability, and low let-7e-3p expression is associated with poorer prognosis. The overexpression of three other miRNAs associated with copy number gain, miR-21-3p, miR-148b-3p and miR-151a-5p, increases proliferation of breast cancer cell lines. In addition, miR-151a-5p enhances the levels of phosphorylated AKT protein. Conclusions Our data provide novel evidence of the mechanisms behind miRNA dysregulation in breast cancer. The study contributes to the understanding of how methylation and copy number alterations influence miRNA expression, emphasizing miRNA functionality through redundant encoding, and suggests novel miRNAs important in breast cancer. PMID:24257477

  14. Rapid selection using G418 of high copy number transformants of Pichia pastoris for high-level foreign gene expression.

    PubMed

    Scorer, C A; Clare, J J; McCombie, W R; Romanos, M A; Sreekrishna, K

    1994-02-01

    Pichia pastoris is a methylotrophic yeast increasingly important in the production of therapeutic proteins. Expression vectors are based on the methanol-inducible AOX1 promoter and are integrated into the host chromosome. In most cases high copy number integration has been shown to be important for high-level expression. Since this occurs at low frequency during transformation, we previously used DNA dot blot screens to identify suitable clones. In this paper we report the use of vectors containing the Tn903 kanr gene conferring G418-resistance. Initial experiments demonstrated that copy number showed a tight correlation with drug-resistance. Using a G418 growth inhibition screen, we readily isolated a series of transformants, containing progressively increasing numbers (1 to 12) of a vector expressing HIV-1 ENV, which we used to examine the relationship between copy number and foreign mRNA levels. Northern blot analysis indicated that ENV mRNA levels from a single-copy clone were nearly as high as AOX1 mRNA, and increased progressively with increasing copy number so as to greatly exceed AOX1 mRNA. We have also developed protocols for the selection, using G418, of high copy number transformants following spheroplast transformation or electroporation. We anticipate that these protocols will simplify the use of Pichia as a biotechnological tool.

  15. Integration of mRNA expression profile, copy number alterations, and microRNA expression levels in breast cancer to improve grade definition.

    PubMed

    Cava, Claudia; Bertoli, Gloria; Ripamonti, Marilena; Mauri, Giancarlo; Zoppis, Italo; Della Rosa, Pasquale Anthony; Gilardi, Maria Carla; Castiglioni, Isabella

    2014-01-01

    Defining the aggressiveness and growth rate of a malignant cell population is a key step in the clinical approach to treating tumor disease. The correct grading of breast cancer (BC) is a fundamental part in determining the appropriate treatment. Biological variables can make it difficult to elucidate the mechanisms underlying BC development. To identify potential markers that can be used for BC classification, we analyzed mRNAs expression profiles, gene copy numbers, microRNAs expression and their association with tumor grade in BC microarray-derived datasets. From mRNA expression results, we found that grade 2 BC is most likely a mixture of grade 1 and grade 3 that have been misclassified, being described by the gene signature of either grade 1 or grade 3. We assessed the potential of the new approach of integrating mRNA expression profile, copy number alterations, and microRNA expression levels to select a limited number of genomic BC biomarkers. The combination of mRNA profile analysis and copy number data with microRNA expression levels led to the identification of two gene signatures of 42 and 4 altered genes (FOXM1, KPNA4, H2AFV and DDX19A) respectively, the latter obtained through a meta-analytical procedure. The 42-based gene signature identifies 4 classes of up- or down-regulated microRNAs (17 microRNAs) and of their 17 target mRNA, and the 4-based genes signature identified 4 microRNAs (Hsa-miR-320d, Hsa-miR-139-5p, Hsa-miR-567 and Hsa-let-7c). These results are discussed from a biological point of view with respect to pathological features of BC. Our identified mRNAs and microRNAs were validated as prognostic factors of BC disease progression, and could potentially facilitate the implementation of assays for laboratory validation, due to their reduced number. PMID:24866763

  16. Identifying In-Trans Process Associated Genes in Breast Cancer by Integrated Analysis of Copy Number and Expression Data

    PubMed Central

    Liestøl, Knut; Lipson, Doron; Nyberg, Sandra; Naume, Bjørn; Sahlberg, Kristine Kleivi; Kristensen, Vessela N.; Børresen-Dale, Anne-Lise; Lingjærde, Ole Christian; Yakhini, Zohar

    2013-01-01

    Genomic copy number alterations are common in cancer. Finding the genes causally implicated in oncogenesis is challenging because the gain or loss of a chromosomal region may affect a few key driver genes and many passengers. Integrative analyses have opened new vistas for addressing this issue. One approach is to identify genes with frequent copy number alterations and corresponding changes in expression. Several methods also analyse effects of transcriptional changes on known pathways. Here, we propose a method that analyses in-cis correlated genes for evidence of in-trans association to biological processes, with no bias towards processes of a particular type or function. The method aims to identify cis-regulated genes for which the expression correlation to other genes provides further evidence of a network-perturbing role in cancer. The proposed unsupervised approach involves a sequence of statistical tests to systematically narrow down the list of relevant genes, based on integrative analysis of copy number and gene expression data. A novel adjustment method handles confounding effects of co-occurring copy number aberrations, potentially a large source of false positives in such studies. Applying the method to whole-genome copy number and expression data from 100 primary breast carcinomas, 6373 genes were identified as commonly aberrant, 578 were highly in-cis correlated, and 56 were in addition associated in-trans to biological processes. Among these in-trans process associated and cis-correlated (iPAC) genes, 28% have previously been reported as breast cancer associated, and 64% as cancer associated. By combining statistical evidence from three separate subanalyses that focus respectively on copy number, gene expression and the combination of the two, the proposed method identifies several known and novel cancer driver candidates. Validation in an independent data set supports the conclusion that the method identifies genes implicated in cancer. PMID

  17. Segmentation of genomic and transcriptomic microarrays data reveals major correlation between DNA copy number aberrations and gene-loci expression.

    PubMed

    Ortiz-Estevez, M; De Las Rivas, J; Fontanillo, C; Rubio, A

    2011-02-01

    DNA copy number aberrations (CNAs) are genetic alterations common in cancer cells. Their transcriptional consequences are still poorly understood. Based on the fact that DNA copy number (CN) is highly correlated with the genomic position, we have applied a segmentation algorithm to gene expression (GE) to explore its relation with CN. We have found a strong correlation between segmented CN (sCN) and segmented GE (sGE), corroborating that CNAs have clear effects on genome-wide expression. We have found out that most of the recurrent regions of sGE are common to those obtained from sCN analysis. Results for two cancer datasets confirm the known targets of aberrations and provide new candidates to study. The suggested methodology allows to find recurrent aberrations specific to sGE, revealing loci where the expression of the genes is independent from their CNs. R code and additional files are available as supplementary material. PMID:21044881

  18. On hydrologic similarity: A dimensionless flood frequency model using a generalized geomorphologic unit hydrograph and partial area runoff generation

    NASA Technical Reports Server (NTRS)

    Sivapalan, Murugesu; Wood, Eric F.; Beven, Keith J.

    1993-01-01

    One of the shortcomings of the original theory of the geomorphologic unit hydrograph (GUH) is that it assumes that runoff is generated uniformly from the entire catchment area. It is now recognized that in many catchments much of the runoff during storm events is produced on partial areas which usually form on narrow bands along the stream network. A storm response model that includes runoff generation on partial areas by both Hortonian and Dunne mechanisms was recently developed by the authors. In this paper a methodology for integrating this partial area runoff generation model with the GUH-based runoff routing model is presented; this leads to a generalized GUH. The generalized GUH and the storm response model are then used to estimate physically based flood frequency distributions. In most previous work the initial moisture state of the catchment had been assumed to be constant for all the storms. In this paper we relax this assumption and allow the initial moisture conditions to vary between storms. The resulting flood frequency distributions are cast in a scaled dimensionless framework where issues such as catchment scale and similarity can be conveniently addressed. A number of experiments are performed to study the sensitivity of the flood frequency response to some of the 'similarity' parameters identified in this formulation. The results indicate that one of the most important components of the derived flood frequency model relates to the specification of processes within the runoff generation model; specifically the inclusion of both saturation excess and Horton infiltration excess runoff production mechanisms. The dominance of these mechanisms over different return periods of the flood frequency distribution can significantly affect the distributional shape and confidence limits about the distribution. Comparisons with observed flood distributions seem to indicate that such mixed runoff production mechanisms influence flood distribution shape. The

  19. Optimization of Dimensionless Figure of Merit in Oxide Thin Film Thermoelectrics

    NASA Astrophysics Data System (ADS)

    Osborne, Daniel; Huxtable, Scott; Tiwari, Ashutosh; Abiade, Jeremiah

    2010-03-01

    The ability of uniquely functional thermoelectric materials to convert waste heat directly into electricity is critical considering the global energy economy. Profitable, energy-efficient thermoelectrics possess thermoelectric figures of merit ZT >= 1. We examined the effect of metal nanoparticle -- oxide film interfaces on the thermal conductivity κ and Seebeck coefficient S in bilayer and multilayer thin film oxide thermoelectrics in an effort to improve the dimensionless figure of merit ZT. Since a thermoelectric's figure of merit ZT is directly proportional to S/κ, reducing κ and increasing S are key strategies to optimize ZT. We reduced κ by phonon scattering due to the inclusion of metal nanoparticles in the bulk of the thermoelectric thin film, and increased S due to energy-dependent electron scattering at the metal - oxide interfaces. Doped strontium titanate (STO) thin film/Au nanoparticle composites were synthesized by alternate ablation of Au and Nb-doped STO targets during pulsed laser deposition. Characterization of the thermoelectric films involve XRD, XPS, and TEM analyses, Seebeck coefficient measurements, and also measurements of the thermal conductivity via time-domain thermoreflectance. The measured thermal conductivities and Seebeck coefficients of the thin films shows a strong dependence on the nanoscale interfaces of the films.

  20. A dimensionless analysis of a 2DOF piezoelectric vibration energy harvester

    NASA Astrophysics Data System (ADS)

    Xiao, Han; Wang, Xu; John, Sabu

    2015-06-01

    In this study, a dimensionless analysis method is proposed to predict the output voltage and harvested power for a 2DOF vibration energy harvesting system. This method allows us to compare the harvesting power and efficiency of the 2DOF vibration energy harvesting system and to evaluate the harvesting system performance regardless the sizes or scales. The analysis method is a hybrid of time domain simulation and frequency response analysis approaches, which would be a useful tool for parametric study, design and optimisation of a 2DOF piezoelectric vibration energy harvester. In a case study, a quarter car suspension model with a piezoelectric material insert is chosen to be studied. The 2DOF vibration energy harvesting system could potentially be applied in a vehicle to convert waste or harmful ambient vibration energy into electrical energy for charging the battery. Especially for its application in a hybrid vehicle or an electrical vehicle, the 2DOF vibration energy harvesting system could improve charge mileage, comfort and reliability.

  1. The Dimensionless Age of the Universe: A Riddle for Our Time

    NASA Astrophysics Data System (ADS)

    Avelino, Arturo; Kirshner, Robert P.

    2016-09-01

    We present the interesting coincidence of cosmology and astrophysics that points toward a dimensionless age of the Universe H 0 t 0 that is close to one. Despite cosmic deceleration for 9 Gyr and acceleration since then, we find H 0 t 0 = 0.96 ± 0.01 for the ΛCDM model that fits SN Ia data from Pan-STARRS, CMB power spectra, and baryon acoustic oscillations. Similarly, astrophysical measures of stellar ages and the Hubble constant derived from redshifts and distances point to H 0 t ˜ 1.0 ± 0.1. The wide range of possible values for H 0 t 0 realized during cosmic evolution means that we live at what appears to be a special time. This “synchronicity problem” is not precisely the same as the usual coincidence problem, because there are combinations of ΩM and ΩΛ for which the usual coincidence problem holds but for which H 0 t 0 is not close to 1.

  2. Impulse excitation of piezoelectric bimorphs for energy harvesting: a dimensionless model

    NASA Astrophysics Data System (ADS)

    Pozzi, Michele

    2014-04-01

    Energy harvesting (EH) is a multidisciplinary research area, involving physics, materials science and engineering, with the objective of providing renewable sources of power sufficient to operate targeted low-power applications. Piezoelectric transducers are often used for inertial vibrational as well as direct excitation EH. However, due to the stiffness of the most common material (PZT), compact and light-weight harvesters have high resonant frequencies, making them inefficient at extracting low-frequency power from the environment. The technique of frequency up-conversion, in the form of either plucking or impulse excitation, aims to bridge this frequency gap. In this paper, the technique is modelled analytically with focus on impulse excitation via impact or shock. An analytical model is developed in a standard way starting from the Euler-Bernoulli beam equations adapted to a piezoelectric bimorph. A set of dimensionless variables and parameters is defined and a system of differential equations derived. Here the system is solved numerically for a wide range of the two group parameters present, covering piezoelectric coupling strength between PVDF and PMN-PT. One major result is that the strength of the coupling strongly affects the timescale of the process, but has only a minor effect on the total energy converted. The model can be readily adapted to different excitation profiles.

  3. Genes and Small RNA Transcripts Exhibit Dosage-Dependent Expression Pattern in Maize Copy-Number Alterations.

    PubMed

    Zuo, Tao; Zhang, Jianbo; Lithio, Andrew; Dash, Sudhansu; Weber, David F; Wise, Roger; Nettleton, Dan; Peterson, Thomas

    2016-07-01

    Copy-number alterations are widespread in animal and plant genomes, but their immediate impact on gene expression is still unclear. In animals, copy-number alterations usually exhibit dosage effects, except for sex chromosomes which tend to be dosage compensated. In plants, genes within small duplications (<100 kb) often exhibit dosage-dependent expression, whereas large duplications (>50 Mb) are more often dosage compensated. However, little or nothing is known about expression in moderately-sized (1-50 Mb) segmental duplications, and about the response of small RNAs to dosage change. Here, we compared maize (Zea mays) plants with two, three, and four doses of a 14.6-Mb segment of chromosome 1 that contains ∼300 genes. Plants containing the duplicated segment exhibit dosage-dependent effects on ear length and flowering time. Transcriptome analyses using GeneChip and RNA-sequencing methods indicate that most expressed genes and unique small RNAs within the duplicated segments exhibit dosage-dependent transcript levels. We conclude that dosage effect is the predominant regulatory response for both genes and unique small RNA transcripts in the segmental dosage series we tested. To our knowledge this is the first analysis of small RNA expression in plant gene dosage variants. Because segmental duplications comprise a significant proportion of eukaryotic genomes, these findings provide important new insight into the regulation of genes and small RNAs in response to dosage changes. PMID:27129738

  4. Assigning numbers to the arrows: Parameterizing a gene regulation network by using accurate expression kinetics

    NASA Astrophysics Data System (ADS)

    Ronen, Michal; Rosenberg, Revital; Shraiman, Boris I.; Alon, Uri

    2002-08-01

    A basic challenge in systems biology is to understand the dynamical behavior of gene regulation networks. Current approaches aim at determining the network structure based on genomic-scale data. However, the network connectivity alone is not sufficient to define its dynamics; one needs to also specify the kinetic parameters for the regulation reactions. Here, we ask whether effective kinetic parameters can be assigned to a transcriptional network based on expression data. We present a combined experimental and theoretical approach based on accurate high temporal-resolution measurement of promoter activities from living cells by using green fluorescent protein (GFP) reporter plasmids. We present algorithms that use these data to assign effective kinetic parameters within a mathematical model of the network. To demonstrate this, we employ a well defined network, the SOS DNA repair system of Escherichia coli. We find a strikingly detailed temporal program of expression that correlates with the functional role of the SOS genes and is driven by a hierarchy of effective kinetic parameter strengths for the various promoters. The calculated parameters can be used to determine the kinetics of all SOS genes given the expression profile of just one representative, allowing a significant reduction in complexity. The concentration profile of the master SOS transcriptional repressor can be calculated, demonstrating that relative protein levels may be determined from purely transcriptional data. This finding opens the possibility of assigning kinetic parameters to transcriptional networks on a genomic scale.

  5. Integrated DNA Copy Number and Gene Expression Regulatory Network Analysis of Non-small Cell Lung Cancer Metastasis

    PubMed Central

    Iranmanesh, Seyed M; Guo, Nancy L

    2014-01-01

    Integrative analysis of multi-level molecular profiles can distinguish interactions that cannot be revealed based on one kind of data in the analysis of cancer susceptibility and metastasis. DNA copy number variations (CNVs) are common in cancer cells, and their role in cell behaviors and relationship to gene expression (GE) is poorly understood. An integrative analysis of CNV and genome-wide mRNA expression can discover copy number alterations and their possible regulatory effects on GE. This study presents a novel framework to identify important genes and construct potential regulatory networks based on these genes. Using this approach, DNA copy number aberrations and their effects on GE in lung cancer progression were revealed. Specifically, this approach contains the following steps: (1) select a pool of candidate driver genes, which have significant CNV in lung cancer patient tumors or have a significant association with the clinical outcome at the transcriptional level; (2) rank important driver genes in lung cancer patients with good prognosis and poor prognosis, respectively, and use top-ranked driver genes to construct regulatory networks with the COpy Number and EXpression In Cancer (CONEXIC) method; (3) identify experimentally confirmed molecular interactions in the constructed regulatory networks using Ingenuity Pathway Analysis (IPA); and (4) visualize the refined regulatory networks with the software package Genatomy. The constructed CNV/mRNA regulatory networks provide important insights into potential CNV-regulated transcriptional mechanisms in lung cancer metastasis. PMID:25392690

  6. Effect of passage number on cellular response to DNA-damaging agents: Cell survival and gene expression

    SciTech Connect

    Chang-Liu, C.M.; Woloschak, G.E.

    1997-08-01

    The effect of different passage numbers on plating efficiency, doubling time, cell growth, and radiation sensitivity was assessed in Syrian hamster embryo (SHE) cells. Changes in gene expression after UV or {gamma}-ray irradiation at different passage numbers were also examined. The SHE cells were maintained in culture medium for up to 64 passages. Cells were exposed to {sup 60}Co {gamma} rays or 254-nm UV radiation. Differential display of cDNAs and northern blots were used for the study of gene expression. With increasing passage number, SHE cells demonstrated decreased doubling time, increased plating efficiency, and a decreased yield in the number of cells per plate. Between passages 41 and 48 a crisis period was evident during which time cell growth in high serum was no longer optimal, and serum concentrations were reduced to maintain cell growth. Sensitivity to ionizing radiation was no different between early- and intermediate-passage cells. However, after UV exposure at low passages (passage 3), confluent cells were more sensitive to the killing effects of UV than were log-phase cells. At intermediate passages (passages 43, 48), confluent cells were slightly more radioresistant than were log-phase cells. By passage 64, however, both confluent and log-phase cells showed similar patterns of UV sensitivity. Expression of {gamma}-actin, PCNA, and p53 transcripts did not change following UV exposure. p53 mRNA was induced following {gamma}-ray exposure of the intermediate (passage 45) epithelial cells. The observed differences in radiation sensitivity associated with increasing passage number may be influenced by radiation-induced gene expression. The authors are conducted experiments to identify these genes.

  7. The number of preproghrelin mRNA expressing cells is increased in mice with activity-based anorexia.

    PubMed

    François, Marie; Barde, Swapnali; Achamrah, Najate; Breton, Jonathan; do Rego, Jean-Claude; Coëffier, Moïse; Hökfelt, Tomas; Déchelotte, Pierre; Fetissov, Sergueï O

    2015-06-01

    Plasma levels of ghrelin, an orexigenic peptide, are increased during conditions of chronic starvation, such as in patients with anorexia nervosa. However, it is not known whether such increase can be related to the number of preproghrelin mRNA-expressing cells in the stomach, and if chronic starvation may activate a tentative central ghrelin production. In this work, in situ hybridization technique was used to analyze the presence and number of preproghrelin mRNA-expressing cells in the stomach and the hypothalamus of mice with activity-based anorexia (ABA) induced by the combination of running wheel activity with progressive, during 10 days, feeding-time restriction (FTR) and compared with sedentary FTR, ABA pair-fed (PF) and ad libitum-fed control mice. All food-restricted mice lost more than 20% of body weight. Body weight loss was similar in ABA and PF mice, but it was more pronounced than in FTR mice. Food intake was also lower in ABA than in FTR mice. Preproghrelin mRNA-expressing cells in the stomach were increased proportionally to the body weight loss in all food-restricted groups with the highest number in ABA mice. No preproghrelin mRNA-producing cells were detectable in the hypothalamus of either control or food-restricted mice. Thus, the increased number of gastric preproghrelin mRNA-producing cells during chronic starvation proportionally to the body weight loss and reduced food intake may underlie increased plasma ghrelin. Hyperactivity-induced anorexia appears to further increase the number of preproghrelin mRNA-producing cells in the stomach. No evidence was found for ghrelin expression in the hypothalamus, not even in any of the present experimental models.

  8. Dimensionless Model of a Thermoelectric Cooling Device Operating at Real Heat Transfer Conditions: Maximum Cooling Capacity Mode

    NASA Astrophysics Data System (ADS)

    Melnikov, A. A.; Kostishin, V. G.; Alenkov, V. V.

    2016-09-01

    Real operating conditions of a thermoelectric cooling device are in the presence of thermal resistances between thermoelectric material and a heat medium or cooling object. They limit performance of a device and should be considered when modeling. Here we propose a dimensionless mathematical steady state model, which takes them into account. Analytical equations for dimensionless cooling capacity, voltage, and coefficient of performance (COP) depending on dimensionless current are given. For improved accuracy a device can be modeled with use of numerical or combined analytical-numerical methods. The results of modeling are in acceptable accordance with experimental results. The case of zero temperature difference between hot and cold heat mediums at which the maximum cooling capacity mode appears is considered in detail. Optimal device parameters for maximal cooling capacity, such as fraction of thermal conductance on the cold side y, fraction of current relative to maximal j' are estimated in range of 0.38-0.44 and 0.48-0.95, respectively, for dimensionless conductance K' = 5-100. Also, a method for determination of thermal resistances of a thermoelectric cooling system is proposed.

  9. Increased numbers of granzyme-B-expressing cytotoxic T-lymphocytes in the small intestine of HIV-infected patients.

    PubMed

    Snijders, F; Wever, P C; Danner, S A; Hack, C E; ten Kate, F J; ten Berge, I J

    1996-07-01

    The objective of this study was to determine whether granzyme B-expressing cells, which identify activated cytotoxic lymphocytes, are present in the small intestinal mucosa of human immunodeficiency virus (HIV)-infected patients with and without diarrhea. Therefore, duodenal biopsy specimens from 29 HIV-infected patients (11 with diarrhea and 18 without diarrhea) and 15 control patients were stained for the presence of granzyme B expressing cells. In HIV-infected patients, a significantly increased expression of granzyme B in the lamina propria was observed (p = 0.00001): In 22 of 29 patients, at least 5-10 cells per high-power field were counted. In contrast, in 13 of 15 control patients, granzyme B was not expressed or minimally so, and in two others a maximum of five granzyme-B-expressing cells could be detected per high-power field. No significant difference was found between the HIV-infected patients with and without diarrhea. Double staining revealed that the granzyme-B-expressing cells were mainly CD3 positive. These data show that activated cytotoxic T lymphocytes (CTLs) are present in the duodenal mucosa of HIV-infected patients. No relation between the number of CTLs and the presence of diarrhea was demonstrated. CTLs are known to be involved in the pathogenesis of HIV infection and in the production of tissue injury, but their functional role in intestinal HIV-related pathology has yet to be elucidated.

  10. A parametric study of wind chill equivalent temperatures by a dimensionless steady-state analysis

    NASA Astrophysics Data System (ADS)

    Shitzer, Avraham

    2006-03-01

    A first order analytical approximation of steady-state heat conduction in a hollow cylinder exchanging heat at its external surface by convection with a cold and windy environment is presented. The model depicts the thermal behavior of certain body elements, e.g., head/face, when exposed to such environments. The results are presented by dimensionless parameters and facilitate the estimation of wind chill equivalent temperatures (WCETs). The effects of several variables on determining WCETs were studied using specific examples, leading to the following generalizations: (1) the conditions assumed for "calm" wind speed appear to be a dominant factor in determining WCET; (2) the effects, on both (skin) surface temperature and on WCET, of a 1°C change in environmental temperature appear to be more pronounced than those of a 1 m/s change in wind speed; (3) similarly, predicted WCETs are more sensitive to the geometrical dimensions assumed for the modeled entity than they are to wind speeds; and (4) tissue thermal conductivity, the angle at which the convective heat transfer coefficient is measured relative to wind direction, and the factor used to establish "effective" wind speeds in the domain occupied by humans relative to reported values, all seem to have relatively small effects on the determination of WCET. These conclusions strongly suggest, among other things, that for any given combination of environmental conditions, wind chill indices may best be presented as ranges rather than as single values. This seems to apply even when worst-case scenarios are considered. Also emphasized is the need for careful and realistic selection of all the parameter values used in the determination of WCETs.

  11. A parametric study of wind chill equivalent temperatures by a dimensionless steady-state analysis.

    PubMed

    Shitzer, Avraham

    2006-03-01

    A first order analytical approximation of steady-state heat conduction in a hollow cylinder exchanging heat at its external surface by convection with a cold and windy environment is presented. The model depicts the thermal behavior of certain body elements, e.g., head/face, when exposed to such environments. The results are presented by dimensionless parameters and facilitate the estimation of wind chill equivalent temperatures (WCETs). The effects of several variables on determining WCETs were studied using specific examples, leading to the following generalizations: (1) the conditions assumed for "calm" wind speed appear to be a dominant factor in determining WCET; (2) the effects, on both (skin) surface temperature and on WCET, of a 1 degrees C change in environmental temperature appear to be more pronounced than those of a 1 m/s change in wind speed; (3) similarly, predicted WCETs are more sensitive to the geometrical dimensions assumed for the modeled entity than they are to wind speeds; and (4) tissue thermal conductivity, the angle at which the convective heat transfer coefficient is measured relative to wind direction, and the factor used to establish "effective" wind speeds in the domain occupied by humans relative to reported values, all seem to have relatively small effects on the determination of WCET. These conclusions strongly suggest, among other things, that for any given combination of environmental conditions, wind chill indices may best be presented as ranges rather than as single values. This seems to apply even when worst-case scenarios are considered. Also emphasized is the need for careful and realistic selection of all the parameter values used in the determination of WCETs.

  12. Expanded numbers of circulating myeloid dendritic cells in patent human filarial infection reflect lower CCR1 expression.

    PubMed

    Semnani, Roshanak Tolouei; Mahapatra, Lily; Dembele, Benoit; Konate, Siaka; Metenou, Simon; Dolo, Housseini; Coulibaly, Michel E; Soumaoro, Lamine; Coulibaly, Siaka Y; Sanogo, Dramane; Seriba Doumbia, Salif; Diallo, Abdallah A; Traoré, Sekou F; Klion, Amy; Nutman, Thomas B; Mahanty, Siddhartha

    2010-11-15

    APC dysfunction has been postulated to mediate some of the parasite-specific T cell unresponsiveness seen in patent filarial infection. We have shown that live microfilariae of Brugia malayi induce caspase-dependent apoptosis in human monocyte-derived dendritic cells (DCs) in vitro. This study addresses whether apoptosis observed in vitro extends to patent filarial infections in humans and is reflected in the number of circulating myeloid DCs (mDCs; CD11c(-)CD123(lo)) in peripheral blood of infected microfilaremic individuals. Utilizing flow cytometry to identify DC subpopulations (mDCs and plasmacytoid DCs [pDCs]) based on expression of CD11c and CD123, we found a significant increase in numbers of circulating mDCs (CD11c(+)CD123(lo)) in filaria-infected individuals compared with uninfected controls from the same filaria-endemic region of Mali. Total numbers of pDCs, monocytes, and lymphocytes did not differ between the two groups. To investigate potential causes of differences in mDC numbers between the two groups, we assessed chemokine receptor expression on mDCs. Our data indicate that filaria-infected individuals had a lower percentage of circulating CCR1(+) mDCs and a higher percentage of circulating CCR5(+) mDCs and pDCs. Finally, live microfilariae of B. malayi were able to downregulate cell-surface expression of CCR1 on monocyte-derived DCs and diminish their calcium flux in response to stimulation by a CCR1 ligand. These findings suggest that microfilaria are capable of altering mDC migration through downregulation of expression of some chemokine receptors and their signaling functions. These observations have major implications for regulation of immune responses to these long-lived parasites. PMID:20956349

  13. Expression of epithelial-mesenchymal transition-related genes increases with copy number in multiple cancer types.

    PubMed

    Zhao, Min; Liu, Yining; Qu, Hong

    2016-04-26

    Epithelial-mesenchymal transition (EMT) is a cellular process through which epithelial cells transform into mesenchymal cells. EMT-implicated genes initiate and promote cancer metastasis because mesenchymal cells have greater invasive and migration capacities than epithelial cells. In this pan-cancer analysis, we explored the relationship between gene expression changes and copy number variations (CNVs) for EMT-implicated genes. Based on curated 377 EMT-implicated genes from the literature, we identified 212 EMT-implicated genes associated with more frequent copy number gains (CNGs) than copy number losses (CNLs) using data from The Cancer Genome Atlas (TCGA). Then by correlating these CNV data with TCGA gene expression data, we identified 71 EMT-implicated genes with concordant CNGs and gene up-regulation in 20 or more tumor samples. Of those, 14 exhibited such concordance in over 110 tumor samples. These 14 genes were predominantly apoptosis regulators, which may implies that apoptosis is critical during EMT. Moreover, the 71 genes with concordant CNG and up-regulation were largely involved in cellular functions such as phosphorylation cascade signaling. This is the first observation of concordance between CNG and up-regulation of specific genes in hundreds of samples, which may indicate that somatic CNGs activate gene expression by increasing the gene dosage.

  14. Expression of epithelial-mesenchymal transition-related genes increases with copy number in multiple cancer types

    PubMed Central

    Qu, Hong

    2016-01-01

    Epithelial-mesenchymal transition (EMT) is a cellular process through which epithelial cells transform into mesenchymal cells. EMT-implicated genes initiate and promote cancer metastasis because mesenchymal cells have greater invasive and migration capacities than epithelial cells. In this pan-cancer analysis, we explored the relationship between gene expression changes and copy number variations (CNVs) for EMT-implicated genes. Based on curated 377 EMT-implicated genes from the literature, we identified 212 EMT-implicated genes associated with more frequent copy number gains (CNGs) than copy number losses (CNLs) using data from The Cancer Genome Atlas (TCGA). Then by correlating these CNV data with TCGA gene expression data, we identified 71 EMT-implicated genes with concordant CNGs and gene up-regulation in 20 or more tumor samples. Of those, 14 exhibited such concordance in over 110 tumor samples. These 14 genes were predominantly apoptosis regulators, which may implies that apoptosis is critical during EMT. Moreover, the 71 genes with concordant CNG and up-regulation were largely involved in cellular functions such as phosphorylation cascade signaling. This is the first observation of concordance between CNG and up-regulation of specific genes in hundreds of samples, which may indicate that somatic CNGs activate gene expression by increasing the gene dosage. PMID:27029057

  15. Limited number of immunoglobulin VH regions expressed in the mutant rabbit "Alicia".

    PubMed

    DiPietro, L A; Short, J A; Zhai, S K; Kelus, A S; Meier, D; Knight, K L

    1990-06-01

    A unique feature of rabbit Ig is the presence of VH region allotypic specificities. In normal rabbits, more than 80% of circulating immunoglobulin molecules bear the VHa allotypic specificities, al, a2 or a3; the remaining 10% to 20% of immunoglobulin molecules lack VHa allotypic specificities and are designated VHa-. A mutant rabbit designated Alicia, in contrast, has predominantly serum immunoglobulin molecules that lack the VHa allotypic specificities (Kelus and Weiss, Proc. Natl. Acad. Sci. USA 1986. 83: 4883). To study the nature and molecular complexity of VHa- molecules, we cloned and determined the nucleotide sequence of seven cDNA prepared from splenic RNA of an Alicia rabbit. Six of the clones appeared to encode VHa- molecules; the framework regions encoded by these clones were remarkably similar to each other, each having an unusual insertion of four amino acids at position 10. This insertion of four amino acids has been seen in only 2 of 54 sequenced rabbit VH genes. The similarity of the sequences of the six VHa- clones to each other and their dissimilarity to most other VH genes leads us to suggest that the VHa- molecules in Alicia rabbits are derived predominantly from one or a small number of very similar VH genes. Such preferential utilization of a small number of VH genes may explain the allelic inheritance of VH allotypes.

  16. Column Number Density Expressions Through M = 0 and M = 1 Point Source Plumes Along Any Straight Path

    NASA Technical Reports Server (NTRS)

    Woronowicz, Michael

    2016-01-01

    Analytical expressions for column number density (CND) are developed for optical line of sight paths through a variety of steady free molecule point source models including directionally-constrained effusion (Mach number M = 0) and flow from a sonic orifice (M = 1). Sonic orifice solutions are approximate, developed using a fair simulacrum fitted to the free molecule solution. Expressions are also developed for a spherically-symmetric thermal expansion (M = 0). CND solutions are found for the most general paths relative to these sources and briefly explored. It is determined that the maximum CND from a distant location through directed effusion and sonic orifice cases occurs along the path parallel to the source plane that intersects the plume axis. For the effusive case this value is exactly twice the CND found along the ray originating from that point of intersection and extending to infinity along the plume's axis. For sonic plumes this ratio is reduced to about 4/3. For high Mach number cases the maximum CND will be found along the axial centerline path. Keywords: column number density, plume flows, outgassing, free molecule flow.

  17. Chromosome 15q11-13 duplication syndrome brain reveals epigenetic alterations in gene expression not predicted from copy number

    PubMed Central

    Hogart, Amber; Leung, Karen N.; Wang, Nicholas J.; Wu, David J.; Driscoll, Jennette; Vallero, Roxanne O.; Schanen, N. Carolyn

    2008-01-01

    Background Chromosome 15q11-13 contains a cluster of imprinted genes essential for normal mammalian neurodevelopment. Deficiencies in paternal or maternal 15q11-13 alleles result in Prader-Willi or Angelman syndromes, respectively, and maternal duplications lead to a distinct condition that often includes autism. Overexpression of maternally expressed imprinted genes is predicted to cause 15q11-13-associated autism, but a link between gene dosage and expression has not been experimentally determined in brain. Methods Post-mortem brain tissue was obtained from a male with 15q11-13 hexasomy and a female with 15q11-13 tetrasomy. Quantitative RT-PCR was used to measure ten 15q11-13 transcripts in maternal 15q11-13 duplication, Prader-Willi syndrome, and control brain samples. Southern blot, bisulfite sequencing and fluorescence in situ hybridization were used to investigate epigenetic mechanisms of gene regulation. Results Gene expression and DNA methylation correlated with parental gene dosage in the male 15q11-13 duplication sample with severe cognitive impairment and seizures. Strikingly, the female with autism and milder Prader-Willi-like characteristics demonstrated unexpected deficiencies in the paternally expressed transcripts SNRPN, NDN, HBII85, and HBII52 and unchanged levels of maternally expressed UBE3A compared to controls. Paternal expression abnormalities in the female duplication sample were consistent with elevated DNA methylation of the 15q11-13 imprinting control region (ICR). Expression of nonimprinted 15q11-13 GABA receptor subunit genes was significantly reduced specifically in the female 15q11-13 duplication brain without detectable GABRB3 methylation differences. Conclusion Our findings suggest that genetic copy number changes combined with additional genetic or environmental influences on epigenetic mechanisms impact outcome and clinical heterogeneity of 15q11-13 duplication syndromes. PMID:18835857

  18. Flower-enhanced expression of a nuclear-encoded mitochondrial respiratory protein is associated with changes in mitochondrion number.

    PubMed Central

    Huang, J; Struck, F; Matzinger, D F; Levings, C S

    1994-01-01

    The mitochondrial Rieske iron-sulfur protein is an obligatory component of the respiratory electron transport chain that is encoded by a single-copy gene in mammals and fungi. In contrast, this protein is encoded by a small gene family in dicotyledonous tobacco and monocotyledonous maize. We cloned four cDNAs from tobacco that encode the mitochondrial Rieske iron-sulfur protein. These clones, along with a previously isolated cDNA, represent five independent members of the gene family that can be divided into three subfamilies. All of these genes were derived from the two progenitor species and were expressed in amphidiploid tobacco. The proteins encoded by these five genes are probably functional because they all contain the universally conserved hexyl peptides necessary for the 2Fe-2S cluster formation. The expression of the Rieske protein gene family is differentially regulated; a 6- to 11-fold higher level of steady state transcripts was found in flowers than in leaves, stems, and roots. Members of at least two subfamilies were preferentially expressed in flowers, indicating that they share a common cis-regulatory element(s), which can respond to a flower-specific signal(s). Although approximately 10 times more transcripts occurred in flowers than in leaves, flower and leaf mitochondria contained a similar amount of the Rieske protein. Flowers, however, contained seven times more Rieske proteins than leaves. These results indicated an increase in mitochondrion number in flowers. High-energy demands during anther development might bring about an increase in mitochondrion numbers in flowers and the flower-enhanced expression of the Rieske protein gene family. Our results suggested that nuclear genes encoding mitochondrial respiratory proteins could sense and respond to changes in energy metabolism and/or changes in mitochondrion numbers. PMID:8180500

  19. Tobacco (Nicotiana tobaccum) nuclear transgenics with high copy number can express NPTII driven by the chloroplast psbA promoter.

    PubMed

    Ye, G N; Pang, S Z; Sanford, J C

    1996-03-01

    A chloroplast expression vector containing the NPTII gene under the control of apsbA promoter (psbA-NPTII) was constructed, and was biolistically delivered into both suspension cells and leaf strips of tobacco (Nicotiana tabaccum). Analyses of subsequently recovered kanamycin-resistant transgenic plants indicate that the psbA-NPTII gene was not located in the chloroplast, but was in the nucleus in very high copy number. This conclusion was based upon results from: (1) Southern hybridization analyses of chloroplast and nuclear DNAs using NPTII, chloroplast-marker, and nuclear-marker probes; (2) pulse-field gel electrophoresis; and (3) kanamycin screening of sexual progenies. This study suggests that the nuclear expression of the NPTII gene may have been associated with many copies of the psbA-NPTII construction. Very high copy number in the nucleus might either allow NPTII expression from the otherwise inadequate psbA promoter, or might increase the chance of recombining with upstream tobacco regulatory sequences. PMID:24178457

  20. Alterations in Gene Expression of Proprotein Convertases in Human Lung Cancer Have a Limited Number of Scenarios

    PubMed Central

    Demidyuk, Ilya V.; Shubin, Andrey V.; Gasanov, Eugene V.; Kurinov, Alexander M.; Demkin, Vladimir V.; Vinogradova, Tatyana V.; Zinovyeva, Marina V.; Sass, Alexander V.; Zborovskaya, Irina B.; Kostrov, Sergey V.

    2013-01-01

    Proprotein convertases (PCs) is a protein family which includes nine highly specific subtilisin-like serine endopeptidases in mammals. The system of PCs is involved in carcinogenesis and levels of PC mRNAs alter in cancer, which suggests expression status of PCs as a possible marker for cancer typing and prognosis. The goal of this work was to assess the information value of expression profiling of PC genes. Quantitative polymerase chain reaction was used for the first time to analyze mRNA levels of all PC genes as well as matrix metalloproteinase genes MMP2 and MMP14, which are substrates of PCs, in 30 matched pairs of samples of human lung cancer tumor and adjacent tissues without pathology. Significant changes in the expression of PCs have been revealed in tumor tissues: increased FURIN mRNA level (p<0.00005) and decreased mRNA levels of PCSK2 (p<0.007), PCSK5 (p<0.0002), PCSK7 (p<0.002), PCSK9 (p<0.00008), and MBTPS1 (p<0.00004) as well as a tendency to increase in the level of PCSK1 mRNA. Four distinct groups of samples have been identified by cluster analysis of the expression patterns of PC genes in tumor vs. normal tissue. Three of these groups covering 80% of samples feature a strong elevation in the expression of a single gene in cancer: FURIN, PCSK1, or PCSK6. Thus, the changes in the expression of PC genes have a limited number of scenarios, which may reflect different pathways of tumor development and cryptic features of tumors. This finding allows to consider the mRNAs of PC genes as potentially important tumor markers. PMID:23409034

  1. Retinoic acid amplifies the host immune response to LPS through increased T lymphocytes number and LPS binding protein expression.

    PubMed

    Seguin-Devaux, Carole; Hanriot, Didier; Dailloux, Michèle; Latger-Cannard, Véronique; Zannad, Faiez; Mertes, Paul-Michel; Longrois, Dan; Devaux, Yvan

    2005-12-21

    Vitamin A deficiency is associated with increased susceptibility to infection but the effects of Vitamin A supplementation on host response to pathogens are controversial. This study investigated the mechanisms by which all-trans retinoic acid (atRA) modulates the host immune response in an experimental model of Vitamin A supplementation before and after challenge with LPS in rats. We show here that a supplementation with five daily injections of 10mg/kg atRA increased the number of T lymphocytes in the peripheral blood. In addition, we show that atRA increased the expression of the LPS binding protein (LBP), a component of the LPS recognition system. The retinoic acid receptor (RAR)alpha agonist Ro 4060-55 but not the pan-retinoid X receptors (RXRs) agonist Ro 2573-86 mimicked the effects of atRA on LBP expression suggesting that atRA enhances LBP expression through a RARalpha-mediated pathway. In order to investigate the significance of increased LBP expression we challenged atRA-supplemented rats with the Gram-positive bacteria Listeria monocytogenes (LM) that activates the immune response independently from LBP. In sharp contrast to our previous observations that atRA supplementation enhances IFN-gamma expression and NOS2 pathway activation in LPS-challenged rats [Devaux, Y., Grosjean, S., Seguin, C., David, C., Dousset, B., Zannad, F., Meistelman, C., de Talancé, N., Mertes, P.M., Ungureanu-Longrois, D., 2000. Retinoic acid and host-pathogen interactions: effects on inducible nitric oxide synthase in vivo. Am. J. Physiol. 279, E1045-E1053], atRA did not increase the LM-induced IFN-gamma expression and NOS2 pathway activation. Overall, these data demonstrate that although atRA induces a "priming" of the immune system characterized by increased T lymphocytes number and LBP expression, the profile of the immune response depends on the inflammatory/infectious stimulus. These results could explain why Vitamin A supplementation could have beneficial/neutral or

  2. Column Number Density Expressions Through M = 0 and M = 1 Point Source Plumes Along Any Straight Path

    NASA Technical Reports Server (NTRS)

    Woronowicz, Michael S.

    2016-01-01

    Analytical expressions for column number density (CND) are developed for optical line of sight paths through a variety of steady free molecule point source models including directionally-constrained effusion (Mach number M = 0) and flow from a sonic orifice (M 1). Sonic orifice solutions are approximate, developed using a fair simulacrum fitted to the free molecule solution. Expressions are also developed for a spherically-symmetric thermal expansion (M = 0). CND solutions are found for the most general paths relative to these sources and briefly explored. It is determined that the maximum CND from a distant location through directed effusion and sonic orifice cases occurs along the path parallel to the source plane that intersects the plume axis. For the effusive case this value is exactly twice the CND found along the ray originating from that point of intersection and extending to infinity along the plumes axis. For sonic plumes this ratio is reduced to about 43. For high Mach number cases the maximum CND will be found along the axial centerline path.

  3. Multiplex titration RT-PCR: rapid determination of gene expression patterns for a large number of genes

    NASA Technical Reports Server (NTRS)

    Nebenfuhr, A.; Lomax, T. L.

    1998-01-01

    We have developed an improved method for determination of gene expression levels with RT-PCR. The procedure is rapid and does not require extensive optimization or densitometric analysis. Since the detection of individual transcripts is PCR-based, small amounts of tissue samples are sufficient for the analysis of expression patterns in large gene families. Using this method, we were able to rapidly screen nine members of the Aux/IAA family of auxin-responsive genes and identify those genes which vary in message abundance in a tissue- and light-specific manner. While not offering the accuracy of conventional semi-quantitative or competitive RT-PCR, our method allows quick screening of large numbers of genes in a wide range of RNA samples with just a thermal cycler and standard gel analysis equipment.

  4. Parvalbumin and neuropeptide Y expressing hippocampal GABA-ergic inhibitory interneuron numbers decline in a model of Gulf War illness

    PubMed Central

    Megahed, Tarick; Hattiangady, Bharathi; Shuai, Bing; Shetty, Ashok K.

    2015-01-01

    Cognitive dysfunction is amongst the most conspicuous symptoms in Gulf War illness (GWI). Combined exposure to the nerve gas antidote pyridostigmine bromide (PB), pesticides and stress during the Persian Gulf War-1 (PGW-1) are presumed to be among the major causes of GWI. Indeed, our recent studies in rat models have shown that exposure to GWI-related (GWIR) chemicals and mild stress for 4 weeks engenders cognitive impairments accompanied with several detrimental changes in the hippocampus. In this study, we tested whether reduced numbers of hippocampal gamma-amino butyric acid (GABA)-ergic interneurons are among the pathological changes induced by GWIR-chemicals and stress. Animals were exposed to low doses of GWIR-chemicals and mild stress for 4 weeks. Three months after this exposure, subpopulations of GABA-ergic interneurons expressing the calcium binding protein parvalbumin (PV), the neuropeptide Y (NPY) and somatostatin (SS) in the hippocampus were stereologically quantified. Animals exposed to GWIR-chemicals and stress for 4 weeks displayed reduced numbers of PV-expressing GABA-ergic interneurons in the dentate gyrus and NPY-expressing interneurons in the CA1 and CA3 subfields. However, no changes in SS+ interneuron population were observed in the hippocampus. Furthermore, GABA-ergic interneuron deficiency in these animals was associated with greatly diminished hippocampus neurogenesis. Because PV+ and NPY+ interneurons play roles in maintaining normal cognitive function and neurogenesis, and controlling the activity of excitatory neurons in the hippocampus, reduced numbers of these interneurons may be one of the major causes of cognitive dysfunction and reduced neurogenesis observed in GWI. Hence, strategies that improve inhibitory neurotransmission in the hippocampus may prove beneficial for reversing cognitive dysfunction in GWI. PMID:25620912

  5. The effect of visitor number and spice provisioning in pacing expression by jaguars evaluated through a case study.

    PubMed

    Vidal, L S; Guilherme, F R; Silva, V F; Faccio, M C S R; Martins, M M; Briani, D C

    2016-06-01

    Captive animals exhibit stereotypic pacing in response to multiple causes, including the inability to escape from human contact. Environmental enrichment techniques can minimize pacing expression. By using an individual-based approach, we addressed whether the amount of time two males and a female jaguar (Panthera onca) devote to pacing varied with the number of visitors and tested the effectiveness of cinnamon and black pepper in reducing pacing. The amount of time that all jaguars engaged in pacing increased significantly with the number of visitors. Despite the difference between the males regarding age and housing conditions, both devoted significantly less time to pacing following the addition of both spices, which indicates their suitability as enrichment techniques. Mean time devoted to pacing among the treatments did not differ for the female. Our findings pointed out to the validity of individual-based approaches, as they can reveal how suitable olfactory stimuli are to minimizing stereotypies irrespective of particular traits.

  6. The effect of visitor number and spice provisioning in pacing expression by jaguars evaluated through a case study.

    PubMed

    Vidal, L S; Guilherme, F R; Silva, V F; Faccio, M C S R; Martins, M M; Briani, D C

    2016-06-01

    Captive animals exhibit stereotypic pacing in response to multiple causes, including the inability to escape from human contact. Environmental enrichment techniques can minimize pacing expression. By using an individual-based approach, we addressed whether the amount of time two males and a female jaguar (Panthera onca) devote to pacing varied with the number of visitors and tested the effectiveness of cinnamon and black pepper in reducing pacing. The amount of time that all jaguars engaged in pacing increased significantly with the number of visitors. Despite the difference between the males regarding age and housing conditions, both devoted significantly less time to pacing following the addition of both spices, which indicates their suitability as enrichment techniques. Mean time devoted to pacing among the treatments did not differ for the female. Our findings pointed out to the validity of individual-based approaches, as they can reveal how suitable olfactory stimuli are to minimizing stereotypies irrespective of particular traits. PMID:26959957

  7. Summary of dimensionless Texas hyetographs and distribution of storm depth developed for Texas Department of Transportation research project 0–4194

    USGS Publications Warehouse

    Asquith, William H.; Roussel, Meghan C.; Thompson, David B.; Cleveland, Theodore G.; Fang, Xing

    2005-01-01

    Hyetographs and storm depth distributions are important elements of hydraulic design by Texas Department of Transportation engineers. Design hyetographs are used in conjunction with unit hydrographs to obtain peak discharge and hydrograph shape for hydraulic design. Storm-depth distributions can be used to assess the probability of a total rainfall depth for a storm. A research project from 2000–2004 has been conducted to (1) determine if existing Natural Resources Conservation Service (NRCS) dimensionless hyetographs are representative of storms in Texas, (2) provide new procedures for dimensionless hyetograph estimation if the NRCS hyetographs are not representative, and (3) provide a procedure to estimate the distribution of storm depth for Texas. This report summarizes the research activities and results of the research project. The report documents several functional models of dimensionless hyetographs and provides curves and tabulated ordinates of empirical (nonfunctional) dimensionless hyetographs for a database of runoff-producing storms in Texas. The dimensionless hyetographs are compared to the NRCS dimensionless hyetographs. The distribution of storm depth is documented for seven values of minimum interevent time through dimensionless frequency curves and tables of mean storm depth for each county in Texas. Conclusions regarding application of the research results are included in the report.

  8. Comparative analyses of gene copy number and mRNA expression in GBM tumors and GBM xenografts

    SciTech Connect

    Hodgson, J. Graeme; Yeh, Ru-Fang; Ray, Amrita; Wang, Nicholas J.; Smirnov, Ivan; Yu, Mamie; Hariono, Sujatmi; Silber, Joachim; Feiler, Heidi S.; Gray, Joe W.; Spellman, Paul T.; Vandenberg, Scott R.; Berger, Mitchel S.; James, C. David

    2009-04-03

    Development of model systems that recapitulate the molecular heterogeneity observed among glioblastoma multiforme (GBM) tumors will expedite the testing of targeted molecular therapeutic strategies for GBM treatment. In this study, we profiled DNA copy number and mRNA expression in 21 independent GBM tumor lines maintained as subcutaneous xenografts (GBMX), and compared GBMX molecular signatures to those observed in GBM clinical specimens derived from the Cancer Genome Atlas (TCGA). The predominant copy number signature in both tumor groups was defined by chromosome-7 gain/chromosome-10 loss, a poor-prognosis genetic signature. We also observed, at frequencies similar to that detected in TCGA GBM tumors, genomic amplification and overexpression of known GBM oncogenes, such as EGFR, MDM2, CDK6, and MYCN, and novel genes, including NUP107, SLC35E3, MMP1, MMP13, and DDX1. The transcriptional signature of GBMX tumors, which was stable over multiple subcutaneous passages, was defined by overexpression of genes involved in M phase, DNA replication, and chromosome organization (MRC) and was highly similar to the poor-prognosis mitosis and cell-cycle module (MCM) in GBM. Assessment of gene expression in TCGA-derived GBMs revealed overexpression of MRC cancer genes AURKB, BIRC5, CCNB1, CCNB2, CDC2, CDK2, and FOXM1, which form a transcriptional network important for G2/M progression and/or checkpoint activation. Our study supports propagation of GBM tumors as subcutaneous xenografts as a useful approach for sustaining key molecular characteristics of patient tumors, and highlights therapeutic opportunities conferred by this GBMX tumor panel for testing targeted therapeutic strategies for GBM treatment.

  9. Differential viral levels and immune gene expression in three stocks of Apis mellifera induced by different numbers of Varroa destructor.

    PubMed

    Khongphinitbunjong, Kitiphong; de Guzman, Lilia I; Tarver, Matthew R; Rinderer, Thomas E; Chen, Yanping; Chantawannakul, Panuwan

    2015-01-01

    The viral levels and immune responses of Italian honey bees (IHB), Russian honey bees (RHB) and an outcross of Varroa Sensitive Hygienic bees (POL) deliberately infested with one or two foundress Varroa were compared. We found that the Deformed wing virus (DWV) level in IHB inoculated with one or two foundress Varroa increased to about 10(3) or 10(5) fold the levels of their uninfested brood. In contrast, POL (10(2) or 10(4) fold) and RHB (10(2) or l0(4) fold) supported a lower increase in DWV levels. The feeding of different stages of Varroa nymphs did not increase DWV levels of their pupal hosts. Analyses of their corresponding Varroa mites showed the same trends: two foundress Varroa yielded higher DWV levels than one foundress, and the addition of nymphs did not increase viral levels. Using the same pupae examined for the presence of viruses, 16 out of 24 genes evaluated showed significant differential mRNA expression levels among the three honey bee stocks. However, only four genes (Defensin, Dscam, PPOact and spaetzle), which were expressed at similar levels in uninfested pupae, were altered by the number of feeding foundress Varroa and levels of DWV regardless of stocks. This research provides the first evidence that immune response profiles of different honey bee stocks are induced by Varroa parasitism.

  10. ACSL6 Is Associated with the Number of Cigarettes Smoked and Its Expression Is Altered by Chronic Nicotine Exposure

    PubMed Central

    Jackson, Kia; van der Vaart, Andrew; Ma, Jennie Z.; Payne, Thomas J.; Sherva, Richard; Farrer, Lindsay A.; Gejman, Pablo; Levinson, Douglas F.; Holmans, Peter; Aggen, Steven H.; Damaj, Imad; Kuo, Po-Hsiu; Webb, Bradley T.; Anton, Raymond; Kranzler, Henry R.; Gelernter, Joel; Li, Ming D.; Kendler, Kenneth S.; Chen, Xiangning

    2011-01-01

    Individuals with schizophrenia tend to be heavy smokers and are at high risk for tobacco dependence. However, the nature of the comorbidity is not entirely clear. We previously reported evidence for association of schizophrenia with SNPs and SNP haplotypes in a region of chromosome 5q containing the SPEC2, PDZ-GEF2 and ACSL6 genes. In this current study, analysis of the control subjects of the Molecular Genetics of Schizophrenia (MGS) sample showed similar pattern of association with number of cigarettes smoked per day (numCIG) for the same region. To further test if this locus is associated with tobacco smoking as measured by numCIG and FTND, we conducted replication and meta-analysis in 12 independent samples (n>16,000) for two markers in ACSL6 reported in our previous schizophrenia study. In the meta-analysis of the replication samples, we found that rs667437 and rs477084 were significantly associated with numCIG (p = 0.00038 and 0.00136 respectively) but not with FTND scores. We then used in vitro and in vivo techniques to test if nicotine exposure influences the expression of ACSL6 in brain. Primary cortical culture studies showed that chronic (5-day) exposure to nicotine stimulated ACSL6 mRNA expression. Fourteen days of nicotine administration via osmotic mini pump also increased ACSL6 protein levels in the prefrontal cortex and hippocampus of mice. These increases were suppressed by injection of the nicotinic receptor antagonist mecamylamine, suggesting that elevated expression of ACSL6 requires nicotinic receptor activation. These findings suggest that variations in the ACSL6 gene may contribute to the quantity of cigarettes smoked. The independent associations of this locus with schizophrenia and with numCIG in non-schizophrenic subjects suggest that this locus may be a common liability to both conditions. PMID:22205969

  11. Human GPR42 is a transcribed multisite variant that exhibits copy number polymorphism and is functional when heterologously expressed

    PubMed Central

    Puhl III, Henry L.; Won, Yu-Jin; Lu, Van B.; Ikeda, Stephen R.

    2015-01-01

    FFAR3 (GPR41) is a G-protein coupled receptor for which short-chain fatty acids serve as endogenous ligands. The receptor is found on gut enteroendocrine L-cells, pancreatic β-cells, and sympathetic neurons, and is implicated in obesity, diabetes, allergic airway disease, and altered immune function. In primates, FFAR3 is segmentally duplicated resulting in GPR42, a gene currently classified as a suspected pseudogene. In this study, we sequenced FFAR3 and GPR42 open reading frames from 56 individuals and found an unexpectedly high frequency of polymorphisms contributing to several complex haplotypes. We also identified a frequent (18.8%) structural variation that results in GPR42 copy number polymorphism. Finally, sequencing revealed that 50.6% of GPR42 haplotypes differed from FFAR3 by only a single non-synonymous substitution and that the GPR42 reference sequence matched only 4.4% of the alleles. Sequencing of cDNA from human sympathetic ganglia and colon revealed processed transcripts matching the GPR42 genotype. Expression of several GPR42 haplotypes in rat sympathetic neurons revealed diverse pharmacological phenotypes that differed in potency and efficacy. Our data suggest that GPR42 be reclassified as a functioning gene and that recognition of sequence and copy number polymorphism of the FFAR3/GPR42 complex be considered during genetic and pharmacological investigation of these receptors. PMID:26260360

  12. A Coursewriter II Function (FCALC) For the Manipulation of Numerical and Algebraic Expressions. Systems Memo Number One.

    ERIC Educational Resources Information Center

    Smith, Authella; And Others

    Documentation of the Coursewriter II Function FCALC is provided. The function is designed for use on the IBM 1500 instructional system and has three major applications: 1) comparison of a numeric expression in buffer 5 with a numeric expression in buffer 0; 2) comparison of an algebraic expression in buffer 5 with an algebraic expression in buffer…

  13. Deciphering the Correlation between Breast Tumor Samples and Cell Lines by Integrating Copy Number Changes and Gene Expression Profiles.

    PubMed

    Sun, Yi; Liu, Qi

    2015-01-01

    Breast cancer is one of the most common cancers with high incident rate and high mortality rate worldwide. Although different breast cancer cell lines were widely used in laboratory investigations, accumulated evidences have indicated that genomic differences exist between cancer cell lines and tissue samples in the past decades. The abundant molecular profiles of cancer cell lines and tumor samples deposited in the Cancer Cell Line Encyclopedia and The Cancer Genome Atlas now allow a systematical comparison of the breast cancer cell lines with breast tumors. We depicted the genomic characteristics of breast primary tumors based on the copy number variation and gene expression profiles and the breast cancer cell lines were compared to different subgroups of breast tumors. We identified that some of the breast cancer cell lines show high correlation with the tumor group that agrees with previous knowledge, while a big part of them do not, including the most used MCF7, MDA-MB-231, and T-47D. We presented a computational framework to identify cell lines that mostly resemble a certain tumor group for the breast tumor study. Our investigation presents a useful guide to bridge the gap between cell lines and tumors and helps to select the most suitable cell line models for personalized cancer studies. PMID:26273658

  14. Prohibitin Expression Deregulation in Gastric Cancer Is Associated with the 3′ Untranslated Region 1630 C>T Polymorphism and Copy Number Variation

    PubMed Central

    Leal, Mariana Ferreira; Cirilo, Priscila Daniele Ramos; Mazzotti, Tatiane Katsue Furuya; Calcagno, Danielle Queiroz; Wisnieski, Fernanda; Demachki, Samia; Martinez, Margarita Cortes; Assumpção, Paulo Pimentel; Chammas, Roger; Burbano, Rommel Rodríguez; Smith, Marília Cardoso

    2014-01-01

    PHB is a reported oncogene and tumor suppressor in gastric cancer. Here, we evaluated whether the PHB copy number and the rs6917 polymorphism affect its expression in gastric cancer. Down-regulation and up-regulation of PHB were observed in the evaluated tumors. Reduced expression was associated with tumor dedifferentiation and cancer initiation. The T allele of the rs6917 polymorphism was associated with reduced PHB mRNA levels. Moreover, the up-regulation of PHB appeared to be regulated by the gain of additional gene copies. Thus, PHB copy number variation and differential expression of the rs6917 polymorphism may play a role in PHB transcriptional regulation. PMID:24879411

  15. Prohibitin expression deregulation in gastric cancer is associated with the 3' untranslated region 1630 C>T polymorphism and copy number variation.

    PubMed

    Leal, Mariana Ferreira; Cirilo, Priscila Daniele Ramos; Mazzotti, Tatiane Katsue Furuya; Calcagno, Danielle Queiroz; Wisnieski, Fernanda; Demachki, Samia; Martinez, Margarita Cortes; Assumpção, Paulo Pimentel; Chammas, Roger; Burbano, Rommel Rodríguez; Smith, Marília Cardoso

    2014-01-01

    PHB is a reported oncogene and tumor suppressor in gastric cancer. Here, we evaluated whether the PHB copy number and the rs6917 polymorphism affect its expression in gastric cancer. Down-regulation and up-regulation of PHB were observed in the evaluated tumors. Reduced expression was associated with tumor dedifferentiation and cancer initiation. The T allele of the rs6917 polymorphism was associated with reduced PHB mRNA levels. Moreover, the up-regulation of PHB appeared to be regulated by the gain of additional gene copies. Thus, PHB copy number variation and differential expression of the rs6917 polymorphism may play a role in PHB transcriptional regulation. PMID:24879411

  16. A dimensionless relative trajectory estimation algorithm for autonomous imaging of a small astronomical body in a close distance flyby

    NASA Astrophysics Data System (ADS)

    Ariu, Kaito; Inamori, Takaya; Funase, Ryu; Nakasuka, Shinichi

    2016-08-01

    The world's first micro-spacecraft, "Proximate Object Close flYby with Optical Navigation" (PROCYON) has the advanced mission to approach an asteroid in dozen km (a one-order closer imaging distance compared with previous probes). In such a close distance encounter, the estimation of the relative trajectory of the target is necessary to perform autonomous imaging. However, the estimation is difficult owing to rapid changes of the line-of-sight direction of the target body. To overcome this problem, a novel dimensionless or direction only relative trajectory estimation algorithm, which uses a least square method, is proposed. The evaluation function for the least square method coincides with the error property of picture information to enable all of its calculations to be recursive and linear. It is suited for the implementation on the limited on-board computer. Numerical simulation results indicate that the proposed algorithm should enable the one-order closer flyby observation.

  17. Approach to designing rotating drum bioreactors for solid-state fermentation on the basis of dimensionless design factors.

    PubMed

    Hardin, M T; Mitchell, D A; Howes, T

    2000-02-01

    The development of large-scale solid-state fermentation (SSF) processes is hampered by the lack of simple tools for the design of SSF bioreactors. The use of semifundamental mathematical models to design and operate SSF bioreactors can be complex. In this work, dimensionless design factors are used to predict the effects of scale and of operational variables on the performance of rotating drum bioreactors. The dimensionless design factor (DDF) is a ratio of the rate of heat generation to the rate of heat removal at the time of peak heat production. It can be used to predict maximum temperatures reached within the substrate bed for given operational variables. Alternatively, given the maximum temperature that can be tolerated during the fermentation, it can be used to explore the combinations of operating variables that prevent that temperature from being exceeded. Comparison of the predictions of the DDF approach with literature data for operation of rotating drums suggests that the DDF is a useful tool. The DDF approach was used to explore the consequences of three scale-up strategies on the required air flow rates and maximum temperatures achieved in the substrate bed as the bioreactor size was increased on the basis of geometric similarity. The first of these strategies was to maintain the superficial flow rate of the process air through the drum constant. The second was to maintain the ratio of volumes of air per volume of bioreactor constant. The third strategy was to adjust the air flow rate with increase in scale in such a manner as to maintain constant the maximum temperature attained in the substrate bed during the fermentation. PMID:10620257

  18. The number of genes changing expression after chronic exposure to code division multiple access or frequency DMA radiofrequency radiation does not exceed the false-positive rate.

    PubMed

    Whitehead, Timothy D; Moros, Eduardo G; Brownstein, Bernard H; Roti Roti, Joseph L

    2006-09-01

    Experiments with cultured C3H 10T 1/2 cells were performed to determine if exposure to cell phone radiofrequency (RF) radiations induce changes in gene expression. Following a 24 h exposure of 5 W/kg specific adsorption rate, RNA was extracted from the exposed and sham control cells for microarray analysis on Affymetrix U74Av2 Genechips. Cells exposed to 0.68 Gy of X-rays with a 4-h recovery were used as positive controls. The number of gene expression changes induced by RF radiation was not greater than the number of false positives expected based on a sham versus sham comparison. In contrast, the X-irradiated samples showed higher numbers of probe sets changing expression level than in the sham versus sham comparison.

  19. Transfer RNA gene numbers may not be completely responsible for the codon usage bias in asparagine, isoleucine, phenylalanine, and tyrosine in the high expression genes in bacteria.

    PubMed

    Satapathy, Siddhartha Sankar; Dutta, Malay; Buragohain, Alak Kumar; Ray, Suvendra Kumar

    2012-08-01

    It is generally believed that the effect of translational selection on codon usage bias is related to the number of transfer RNA genes in bacteria, which is more with respect to the high expression genes than the whole genome. Keeping this in the background, we analyzed codon usage bias with respect to asparagine, isoleucine, phenylalanine, and tyrosine amino acids. Analysis was done in seventeen bacteria with the available gene expression data and information about the tRNA gene number. In most of the bacteria, it was observed that codon usage bias and tRNA gene number were not in agreement, which was unexpected. We extended the study further to 199 bacteria, limiting to the codon usage bias in the two highly expressed genes rpoB and rpoC which encode the RNA polymerase subunits β and β', respectively. In concordance with the result in the high expression genes, codon usage bias in rpoB and rpoC genes was also found to not be in agreement with tRNA gene number in many of these bacteria. Our study indicates that tRNA gene numbers may not be the sole determining factor for translational selection of codon usage bias in bacterial genomes.

  20. Empirical, dimensionless, cumulative-rainfall hyetographs developed from 1959-86 storm data for selected small watersheds in Texas

    USGS Publications Warehouse

    Williams-Sether, Tara; Asquith, William H.; Thompson, David B.; Cleveland, Theodore G.; Fang, Xing

    2004-01-01

    A database of incremental cumulative-rainfall values for storms that occurred in small urban and rural watersheds in north and south central Texas during the period from 1959 to 1986 was used to develop empirical, dimensionless, cumulative-rainfall hyetographs. Storm-quartile classifications were determined from the cumulative-rainfall values, which were divided into data groups on the basis of storm-quartile classification (first, second, third, fourth, and first through fourth combined), storm duration (0 to 6, 6 to 12, 12 to 24, 24 to 72, and 0 to 72 hours), and rainfall amount (1 inch or more). Removal of long leading tails, in effect, shortened the storm duration and, in some cases, affected the storm-quartile classification. Therefore, two storm groups, untrimmed and trimmed, were used for analysis. The trimmed storms generally are preferred for interpretation. For a 12-hour or less trimmed storm duration, approximately 49 percent of the storms are first quartile. For trimmed storm durations of 12 to 24 and 24 to 72 hours, 47 and 38 percent, respectively, of the storms are first quartile. For a trimmed storm duration of 0 to 72 hours, the first-, second-, third-, and fourth-quartile storms accounted for 46, 21, 20, and 13 percent of all storms, respectively. The 90th-percentile curve for first-quartile storms indicated about 90 percent of the cumulative rainfall occurs during the first 20 percent of the storm duration. The 10th-percentile curve for first-quartile storms indicated about 30 percent of the cumulative rainfall occurs during the first 20 percent of the storm duration. The 90th-percentile curve for fourth-quartile storms indicated about 33 percent of the cumulative rainfall occurs during the first 20 percent of the storm duration. The 10th-percentile curve for fourth-quartile storms indicated less than 5 percent of the cumulative rainfall occurs during the first 20 percent of the storm duration. Statistics for the empirical, dimensionless

  1. Number Guessing

    ERIC Educational Resources Information Center

    Sezin, Fatin

    2009-01-01

    It is instructive and interesting to find hidden numbers by using different positional numeration systems. Most of the present guessing techniques use the binary system expressed as less-than, greater-than or present-absent type information. This article describes how, by employing four cards having integers 1-64 written in different colours, one…

  2. Determination of protein expression and plasmid copy number from cloned genes in Escherichia coli by flow injection analysis using an enzyme indicator vector.

    PubMed

    Schendel, F J; Baude, E J; Flickinger, M C

    1989-10-20

    On-line determination of expression rates from cloned genes in Escherichia coli and of plasmid copy number would be useful for monitoring accumulation of non-secreted proteins. As an initial model for monitoring gene expression in intact cells, a non-gene-fusion enzyme-based indicator plasmid has been constructed containing the phoA gene coding for alkaline phosphatase (AP) in pUCIS and pACYC184. The activity of AP can be rapidly determined in permeabilized cells. A flow injection analysis (FIA) assay has been developed which allows the direct real-time measurement of the AP activity during cell growth. A model target gene coding for E. coli cyanase (cynS) has been inserted in order to determine the ratio between the expression of the target and indicator, AP. A linear relationship has been found between plasmid copy number and AP activity for the high-copy pUC vector. To minimize indicator expression, transcription terminators have been inserted between the cynS and phoA genes, altering the target-to-indicator ratio by 10- to 40-fold. These vectors may be useful for the rapid continuous determination of plasmid copy number and target gene expression for nonsecreted proteins and would overcome the limitations of in situ probe biosensors for real-time determination of the accumulation of proteins from cloned genes in E. coli.

  3. BAC TG-EMBED: one-step method for high-level, copy-number-dependent, position-independent transgene expression

    PubMed Central

    Bian, Qian; Belmont, Andrew S.

    2010-01-01

    Chromosome position effects combined with transgene silencing of multi-copy plasmid insertions lead to highly variable and usually quite low expression levels of mini-genes integrated into mammalian chromosomes. Together, these effects greatly complicate obtaining high-level expression of therapeutic proteins in mammalian cells or reproducible expression of individual or multiple transgenes. Here, we report a simple, one-step procedure for obtaining high-level, reproducible mini-gene expression in mammalian cells. By inserting mini-genes at different locations within a BAC containing the DHFR housekeeping gene locus, we obtain copy-number-dependent, position-independent expression with chromosomal insertions of one to several hundred BAC copies. These multi-copy DHFR BAC insertions adopt similar large-scale chromatin conformations independent of their chromosome integration site, including insertions within centromeric heterochromatin. Prevention of chromosome position effects, therefore, may be the result of embedding the mini-gene within the BAC-specific large-scale chromatin structure. The expression of reporter mini-genes can be stably maintained during continuous, long-term culture in the presence of drug selection. Finally, we show that this method is extendable to reproducible, high-level expression of multiple mini-genes, providing improved expression of both single and multiple transgenes. PMID:20385594

  4. A dimensionless dynamic contrast enhanced MRI parameter for intra-prostatic tumour target volume delineation: initial comparison with histology

    NASA Astrophysics Data System (ADS)

    Hrinivich, W. Thomas; Gibson, Eli; Gaed, Mena; Gomez, Jose A.; Moussa, Madeleine; McKenzie, Charles A.; Bauman, Glenn S.; Ward, Aaron D.; Fenster, Aaron; Wong, Eugene

    2014-03-01

    Purpose: T2 weighted and diffusion weighted magnetic resonance imaging (MRI) show promise in isolating prostate tumours. Dynamic contrast enhanced (DCE)-MRI has also been employed as a component in multi-parametric tumour detection schemes. Model-based parameters such as Ktrans are conventionally used to characterize DCE images and require arterial contrast agent (CR) concentration. A robust parameter map that does not depend on arterial input may be more useful for target volume delineation. We present a dimensionless parameter (Wio) that characterizes CR wash-in and washout rates without requiring arterial CR concentration. Wio is compared to Ktrans in terms of ability to discriminate cancer in the prostate, as demonstrated via comparison with histology. Methods: Three subjects underwent DCE-MRI using gadolinium contrast and 7 s imaging temporal resolution. A pathologist identified cancer on whole-mount histology specimens, and slides were deformably registered to MR images. The ability of Wio maps to discriminate cancer was determined through receiver operating characteristic curve (ROC) analysis. Results: There is a trend that Wio shows greater area under the ROC curve (AUC) than Ktrans with median AUC values of 0.74 and 0.69 respectively, but the difference was not statistically significant based on a Wilcoxon signed-rank test (p = 0.13). Conclusions: Preliminary results indicate that Wio shows potential as a tool for Ktrans QA, showing similar ability to discriminate cancer in the prostate as Ktrans without requiring arterial CR concentration.

  5. Characterization of gear faults in variable rotating speed using Hilbert-Huang Transform and instantaneous dimensionless frequency normalization

    NASA Astrophysics Data System (ADS)

    Wu, T. Y.; Chen, J. C.; Wang, C. C.

    2012-07-01

    The objective of this research is to investigate the feasibility of utilizing the instantaneous dimensionless frequency (DLF) normalization and Hilbert-Huang Transform (HHT) to characterize the different gear faults in case of variable rotating speed. The normalized DLF of the vibration signals are calculated based on the rotating speed of shaft and the instantaneous frequencies of Intrinsic Mode Functions (IMFs) which are decomposed by Empirical Mode Decomposition (EMD) process. The faulty gear features on DLF-energy distribution of vibration signal can be extracted without the presence of shaft rotating speed, so that the proposed approach can be applied for characterizing the malfunctions of gearbox system under variable shaft rotating speed. A test rig of gear transmission system is performed to illustrate the gear faults, including worn tooth, broken tooth and gear unbalance. Different methods to determine the instantaneous frequency are employed to verify the consistence of characterization results. The DLF-energy distributions of vibration signals are investigated in different faulty gear conditions. The analysis results demonstrate the capability and effectiveness of the proposed approach for characterizing the gear malfunctions at the DLFs corresponding to the meshing frequency as well as the shaft rotating frequency. The support vector machine (SVM) is then employed to classify the vibration patterns of gear transmission system at different malfunctions. Using the energy distribution at the characteristic DLFs as the features, the different fault types of gear can be identified by SVM with high accuracy.

  6. Assessment of Tumor Heterogeneity, as Evidenced by Gene Expression Profiles, Pathway Activation, and Gene Copy Number, in Patients with Multifocal Invasive Lobular Breast Tumors

    PubMed Central

    Norton, Nadine; Advani, Pooja P.; Serie, Daniel J.; Geiger, Xochiquetzal J.; Necela, Brian M.; Axenfeld, Bianca C.; Kachergus, Jennifer M.; Feathers, Ryan W.; Carr, Jennifer M.; Crook, Julia E.; Moreno-Aspitia, Alvaro; Anastasiadis, Panos Z.; Perez, Edith A.; Thompson, E. Aubrey

    2016-01-01

    Background Invasive lobular carcinoma (ILC) comprises approximately ~10–20% of breast cancers. In general, multifocal/multicentric (MF/MC) breast cancer has been associated with an increased rate of regional lymph node metastases. Tumor heterogeneity between foci represents a largely unstudied source of genomic variation in those rare patients with MF/MC ILC. Methods We characterized gene expression and copy number in 2 or more foci from 11 patients with MF/MC ILC (all ER+, HER2-) and adjacent normal tissue. RNA and DNA were extracted from 3x1.5mm cores from all foci. Gene expression (730 genes) and copy number (80 genes) were measured using Nanostring PanCancer and Cancer CNV panels. Linear mixed models were employed to compare expression in tumor versus normal samples from the same patient, and to assess heterogeneity (variability) in expression among multiple ILC within an individual. Results 35 and 34 genes were upregulated (FC>2) and down-regulated (FC<0.5) respectively in ILC tumor relative to adjacent normal tissue, q<0.05. 9/34 down-regulated genes (FIGF, RELN, PROM1, SFRP1, MMP7, NTRK2, LAMB3, SPRY2, KIT) had changes larger than CDH1, a hallmark of ILC. Copy number changes in these patients were relatively few but consistent across foci within each patient. Amplification of three genes (CCND1, FADD, ORAOV1) at 11q13.3 was present in 2/11 patients in both foci. We observed significant evidence of within-patient between-foci variability (heterogeneity) in gene expression for 466 genes (p<0.05 with FDR 8%), including CDH1, FIGF, RELN, SFRP1, MMP7, NTRK2, LAMB3, SPRY2 and KIT. Conclusions There was substantial variation in gene expression between ILC foci within patients, including known markers of ILC, suggesting an additional level of complexity that should be addressed. PMID:27078887

  7. Increased levels of prolactin receptor expression correlate with the early onset of lupus symptoms and increased numbers of transitional-1 B cells after prolactin treatment

    PubMed Central

    2012-01-01

    Background Prolactin is secreted from the pituitary gland and other organs, as well as by cells such as lymphocytes. Prolactin has an immunostimulatory effect and is associated with autoimmune diseases that are characterised by abnormal B cell activation, such as systemic lupus erythematosus (SLE). Our aim was to determine if different splenic B cell subsets express the prolactin receptor and if the presence of prolactin influences these B cell subsets and correlates with development of lupus. Results Using real-time PCR and flow cytometry, we found that different subsets of immature (transitional) and mature (follicular, marginal zone) B cells express different levels of the prolactin receptor and are differentially affected by hyperprolactinaemia. We found that transitional B cells express the prolactin receptor at higher levels compared to mature B cells in C57BL/6 mice and the lupus-prone MRL/lpr and MRL mouse strains. Transitional-1 (T1) B cells showed a higher level of prolactin receptor expression in both MRL/lpr and MRL mice compared to C57BL/6 mice. Hyperprolactinaemia was induced using metoclopramide, which resulted in the development of early symptoms of SLE. We found that T1 B cells are the main targets of prolactin and that prolactin augments the absolute number of T1 B cells, which reflects the finding that this B cell subpopulation expresses the highest level of the prolactin receptor. Conclusions We found that all B cell subsets express the prolactin receptor but that transitional B cells showed the highest prolactin receptor expression levels. Hyperprolactinaemia in mice susceptible to lupus accelerated the disease and increased the absolute numbers of T1 and T3 B cells but not of mature B cells, suggesting a primary effect of prolactin on the early stages of B cell maturation in the spleen and a role of prolactin in B cell differentiation, contributing to SLE onset. PMID:22404893

  8. Influence of the number of vehicles in the emergence of sound events on the annoyance expressed - experimental study

    NASA Technical Reports Server (NTRS)

    Vallet, M.

    1982-01-01

    The acoustical index leg was studied to determine its accuracy in predicting annoyance from traffic noise. Annoyance was tested in experimental situations where the frequency of the number of heavy vehicles varied from 3 to 30 HV/30 min for different classes of the Leg level at 50, 55, 60 dB(A) of traffic noise. The results showed that: (1) for a constant Leg level the annoyance increases as a function of the number of HV up to a certain threshold at which the annoyance is stabilized; (2) for a constant frequency of passage of HV, the annoyance increases with the Leg level; (3) composite indexes of the type Leg + Log NHV, L1 + EMER or L1 + L10 give a predictive value greater than that of the Leg pr Log nHV taken alone.

  9. A series of medium and high copy number arabinose-inducible Escherichia coli expression vectors compatible with pBR322 and pACYC184.

    PubMed

    Chakravartty, Vandana; Cronan, John E

    2015-09-01

    The original pBAD24 plasmid and the derived lower copy number (the pBAD322 series) expression vectors have been widely used in Escherichia coli, Salmonella enterica, and related bacteria. However, a flexible pBAD expression system has been available only in pMB1 (ColE1) vectors. We report a series of pBAD vectors that replicate using the origin of plasmid RSF1030 that are compatible with pMB1 (ColE1) and p15A (pACYC) vectors. Both high (≥pBAD24) and medium (~pBAD322) copy number plasmids encoding resistance to ampicillin, chloramphenicol, kanamycin, tetracycline, spectinomycin/streptomycin, gentamycin, or trimethoprim are available.

  10. Expression of platelet-bound stromal-cell derived factor-1 (SDF-1) and number of CD34(+) progenitor cells in patients with congestive heart failure.

    PubMed

    Jorbenadze, Rezo; Schleicher, Erwin; Bigalke, Boris; Stellos, Konstantinos; Gawaz, Meinrad

    2014-01-01

    Platelet-bound stromal cell-derived factor-1 (SDF-1) plays a crucial role in attachment of circulating CD34(+) progenitor cells to the vascular wall, facilitating tissue healing after injury. However there is no evidence about expression of platelet-bound SDF-1 in patients with congestive heart failure (CHF). The aim of our study was to evaluate expression of platelet-bound SDF-1 and number of CD34(+) progenitor cells in patients with CHF. Forty-eight patients with idiopathic dilated cardiomyopathy (DCM) and 61 patients with ischaemic cardiomyopathy (ICM) were consecutively enrolled into the study. Blood taken from 109 consecutive patients was studied for surface expression of platelet-bound SDF-1 and number of CD34(+) progenitor cells by flow cytometry. The highest expression of platelet-bound SDF-1 was observed in patients with severe impairment of left ventricular systolic function compared with patients with mild or moderate impairment of left ventricular systolic function (mild vs. moderate vs. severe impairment of left ventricular systolic function: MFI ± SD: 35.6 ± 34 vs. 101.45 ± 73 vs. 124.86 ± 86.7, Kruskal-Wallis p < 0.001). Similar to platelet-bound SDF-1 number of CD34(+) progenitor cells was the highest in severe impairment of left ventricular systolic function (mild vs. moderate vs. severe impairment of left ventricular systolic function: mean ± SD: 260.4 ± 177.5 vs. 580.7 ± 340.5 vs. 640.82 ± 370.6, Kruskal-Wallis p < 0.001). Platelet-bound SDF-1 expression was associated with number of circulating CD34(+) progenitor cells (r = 0.454, p < 0.001) in patients with CHF. Expression of platelet-bound SDF-1 and number of CD34(+) cells were higher in patients with DCM compared with patients with ICM (p < 0.001 for both) and inversely correlated with age and aspirin therapy. Platelet-bound SDF-1 and CD34(+) progenitor cells are especially increased in patients with severe impairment of left

  11. FGFR3 mutations, but not FGFR3 expression and FGFR3 copy-number variations, are associated with favourable non-muscle invasive bladder cancer.

    PubMed

    Neuzillet, Yann; van Rhijn, Bas W G; Prigoda, Nadia L; Bapat, Bharati; Liu, Liyang; Bostrom, Peter J; Fleshner, Neil E; Gallie, Brenda L; Zlotta, Alexandre R; Jewett, Michael A S; van der Kwast, Theo H

    2014-08-01

    The fibroblast growth factor receptor 3 (FGFR3) is a tyrosine kinase receptor frequently activated by point mutations in bladder cancer (BC). These mutations are associated with genetically stable, Ta and low-grade BC, representing the favourable BC pathway. Conversely, FGFR3 over-expression was recently found in 40 % of muscle invasive BC. We examined FGFR3 mutation status and protein expression in patients originally diagnosed as T1. We also investigated copy-number variations in FGFR3 as a possible alternative mechanism to activate FGFR3. We included 84 patients with T1 BC as their initial diagnosis. A uropathologist reviewed the slides for grade and (sub)stage. The FGFR3 mutation status was examined by PCR-SNaPshot and FGFR3 protein expression by standard immuno-histochemistry (FGFR3-B9). Copy-number status was determined in 69/84 cases with nine probes covering nine exons of the FGFR3 gene (MLPA). Of 27 BC with FGFR3 mutations, 26 (96 %) showed FGFR3 over-expression. Of the 57 wild-type BC, 27 (47 %) BC showed over-expression. Pathological parameters significantly differed (p < 0.01) between mutant and wild-type tumours with the FGFR3 mutation pointing to more favourable BC. However, if the BC exhibited wild-type FGFR3, FGFR3 protein status had no influence on grade and (sub)stage. We found six tumours with more than or equal to three copies of FGFR3. Only 1 of 22 wild-type tumours with over-expression of FGFR3 had more than or equal to three gene copies. In initially diagnosed T1 BC, only the FGFR3 mutation was significantly associated with favourable BC disease characteristics. In addition to almost all FGFR3 mutant BC, 47 % of wild-type BC displayed FGFR3 over-expression, suggesting an alternative mechanism to activate FGFR3. Increased FGFR3 copy number was a rare event and did not account for this mechanism. Nevertheless, FGFR3 wild-type tumours with over-expression of the protein may still represent a subset that might potentially benefit from FGFR3

  12. ON THE ELECTRON-TO-NEUTRAL NUMBER DENSITY RATIO IN THE COMA OF COMET 67P/CHURYUMOV–GERASIMENKO: GUIDING EXPRESSION AND SOURCES FOR DEVIATIONS

    SciTech Connect

    Vigren, E.; Eriksson, A. I.; Edberg, N. J. T.; Odelstad, E.; Galand, M.; Schwartz, S. J.

    2015-10-10

    We compute partial photoionization frequencies of H{sub 2}O, CO{sub 2}, and CO, the major molecules in the coma of comet 67P/Churyumov–Gerasimenko, the target comet of the ongoing ESA Rosetta mission. Values are computed from Thermosphere Ionosphere Mesosphere Energy and Dynamics/Solar EUV Experiment solar EUV spectra for 2014 August 1, 2015 March 1, and for perihelion (2015 August, as based on prediction). From the varying total photoionization frequency of H{sub 2}O, as computed from 2014 August 1 to 2015 May 20, we derive a simple analytical expression for the electron-to-neutral number density ratio as a function of cometocentric and heliocentric distance. The underlying model assumes radial movement of the coma constituents and does not account for chemical loss or the presence of electric fields. We discuss various effects/processes that can cause deviations between values from the analytical expression and actual electron-to-neutral number density ratios. The analytical expression is thus not strictly meant as predicting the actual electron-to-neutral number density ratio, but is useful in comparisons with observations as an indicator of processes at play in the cometary coma.

  13. On the Electron-to-Neutral Number Density Ratio in the Coma of Comet 67P/Churyumov-Gerasimenko: Guiding Expression and Sources for Deviations

    NASA Astrophysics Data System (ADS)

    Vigren, E.; Galand, M.; Eriksson, A. I.; Edberg, N. J. T.; Odelstad, E.; Schwartz, S. J.

    2015-10-01

    We compute partial photoionization frequencies of H2O, CO2, and CO, the major molecules in the coma of comet 67P/Churyumov-Gerasimenko, the target comet of the ongoing ESA Rosetta mission. Values are computed from Thermosphere Ionosphere Mesosphere Energy and Dynamics/Solar EUV Experiment solar EUV spectra for 2014 August 1, 2015 March 1, and for perihelion (2015 August, as based on prediction). From the varying total photoionization frequency of H2O, as computed from 2014 August 1 to 2015 May 20, we derive a simple analytical expression for the electron-to-neutral number density ratio as a function of cometocentric and heliocentric distance. The underlying model assumes radial movement of the coma constituents and does not account for chemical loss or the presence of electric fields. We discuss various effects/processes that can cause deviations between values from the analytical expression and actual electron-to-neutral number density ratios. The analytical expression is thus not strictly meant as predicting the actual electron-to-neutral number density ratio, but is useful in comparisons with observations as an indicator of processes at play in the cometary coma.

  14. Photoperiod affects the expression of sex and species differences in leukocyte number and leukocyte trafficking in congeneric hamsters.

    PubMed

    Bilbo, S D; Dhabhar, F S; Viswanathan, K; Saul, A; Nelson, R J

    2003-11-01

    Sex differences in immune function are well documented. These sex differences may be modulated by social and environmental factors. Individuals of polygynous species generally exhibit more pronounced sex differences in immune parameters than individuals of monogamous species, often displaying an energetic trade-off between enhanced immunity and high mating success. During winter, animals contend with environmental conditions (e.g. low temperatures and decreased food availability) that evoke energetic-stress responses; many mammals restrict reproduction in response to photoperiod as part of an annual winter coping strategy. To test the hypothesis that extant sex and species differences in immune surveillance may be modulated by photoperiod, we examined leukocyte numbers in males and females of two closely related hamster species (Phodopus). As predicted, uniparental P. sungorus exhibited a robust sex difference, with total white blood cells, total lymphocytes, T cells, and B cells higher in females than males, during long days when reproduction occurs, but not during short days when reproduction usually stops. In contrast, biparental male and female P. campbelli exhibited comparable leukocyte numbers during both long and short days. To study sex differences in stress responses, we also examined immune cell trafficking in response to an acute (2 h) restraint stressor. During stressful challenges, it appears beneficial for immune cells to exit the blood and move to primary immune defense areas such as the skin, in preparation for potential injury or infection. Acute stress moved lymphocytes and monocytes out of the blood in all animals. Blood cortisol concentrations were increased in P. sungorus females compared to males at baseline (52%) and in response to restraint stress (38%), but only in long days. P. campbelli males and females exhibited comparable blood cortisol and stress responses during both long and short days. Our results suggest that interactions among

  15. Ectopic phytocystatin expression increases nodule numbers and influences the responses of soybean (Glycine max) to nitrogen deficiency.

    PubMed

    Quain, Marian D; Makgopa, Matome E; Cooper, James W; Kunert, Karl J; Foyer, Christine H

    2015-04-01

    Cysteine proteases and cystatins have many functions that remain poorly characterised, particularly in crop plants. We therefore investigated the responses of these proteins to nitrogen deficiency in wild-type soybeans and in two independent transgenic soybean lines (OCI-1 and OCI-2) that express the rice cystatin, oryzacystatin-I (OCI). Plants were grown for four weeks under either a high (5 mM) nitrate (HN) regime or in the absence of added nitrate (LN) in the absence or presence of symbiotic rhizobial bacteria. Under the LN regime all lines showed similar classic symptoms of nitrogen deficiency including lower shoot biomass and leaf chlorophyll. However, the LN-induced decreases in leaf protein and increases in root protein tended to be smaller in the OCI-1 and OCI-2 lines than in the wild type. When LN-plants were grown with rhizobia, OCI-1 and OCI-2 roots had significantly more crown nodules than wild-type plants. The growth nitrogen regime had a significant effect on the abundance of transcripts encoding vacuolar processing enzymes (VPEs), LN-dependent increases in VPE2 and VPE3 transcripts in all lines. However, the LN-dependent increases of VPE2 and VPE3 transcripts were significantly lower in the leaves of OCI-1 and OCI-2 plants than in the wild type. These results show that nitrogen availability regulates the leaf and root cysteine protease, VPE and cystatin transcript profiles in a manner that is in some cases influenced by ectopic OCI expression. Moreover, the OCI-dependent inhibition of papain-like cysteine proteases favours increased nodulation and enhanced tolerance to nitrogen limitation, as shown by the smaller LN-dependent decreases in leaf protein observed in the OCI-1 and OCI-2 plants relative to the wild type.

  16. Increased expression and copy number amplification of LINE-1 and SINE B1 retrotransposable elements in murine mammary carcinoma progression.

    PubMed

    Gualtieri, Alberto; Andreola, Federica; Sciamanna, Ilaria; Sinibaldi-Vallebona, Paola; Serafino, Annalucia; Spadafora, Corrado

    2013-11-01

    In higher eukaryotic genomes, Long Interspersed Nuclear Element 1 (LINE-1) retrotransposons and endogenous retroviruses represent large families of repeated elements encoding reverse transcriptase (RT) proteins. Short Interspersed Nuclear Element B1 (SINE B1) retrotrasposons do not encode RT, but use LINE-1-derived RT for their retrotransposition. We previously showed that many cancer types have an abundant endogenous RT activity. Inhibition of that activity, by either RNA interference-dependent silencing of active LINE-1 elements or by RT inhibitory drugs, reduced proliferation and promoted differentiation in cancer cells, indicating that LINE-1-encoded RT is required for tumor progression. Using MMTV-PyVT transgenic mice as a well-defined model of breast cancer progression, we now report that both LINE-1 and SINE B1 retrotransposons are up-regulated at a very early stage of tumorigenesis; LINE-1-encoded RT product and enzymatic activity were detected in tumor tissues as early as stage 1, preceding the widespread appearance of histological alterations and specific cancer markers, and further increased in later progression stages, while neither was present in non-pathological breast tissues. Importantly, both LINE-1 and SINE B1 retrotransposon families undergo copy number amplification during tumor progression. These findings therefore indicate that RT activity is distinctive of breast cancer cells and that, furthermore, LINE-1 and SINE B1 undergo copy number amplification during cancer progression.

  17. Genome-Wide Analysis of DNA Methylation, Copy Number Variation, and Gene Expression in Monozygotic Twins Discordant for Primary Biliary Cirrhosis

    PubMed Central

    Selmi, Carlo; Cavaciocchi, Francesca; Lleo, Ana; Cheroni, Cristina; De Francesco, Raffaele; Lombardi, Simone A.; De Santis, Maria; Meda, Francesca; Raimondo, Maria Gabriella; Crotti, Chiara; Folci, Marco; Zammataro, Luca; Mayo, Marlyn J.; Bach, Nancy; Shimoda, Shinji; Gordon, Stuart C.; Miozzo, Monica; Invernizzi, Pietro; Podda, Mauro; Scavelli, Rossana; Martin, Michelle R.; Seldin, Michael F.; LaSalle, Janine M.; Gershwin, M. Eric

    2014-01-01

    Primary biliary cirrhosis (PBC) is an uncommon autoimmune disease with a homogeneous clinical phenotype that reflects incomplete disease concordance in monozygotic (MZ) twins. We have taken advantage of a unique collection consisting of genomic DNA and mRNA from peripheral blood cells of female MZ twins (n = 3 sets) and sisters of similar age (n = 8 pairs) discordant for disease. We performed a genome-wide study to investigate differences in (i) DNA methylation (using a custom tiled four-plex array containing tiled 50-mers 19,084 randomly chosen methylation sites), (ii) copy number variation (CNV) (with a chip including markers derived from the 1000 Genomes Project, all three HapMap phases, and recently published studies), and/or (iii) gene expression (by whole-genome expression arrays). Based on the results obtained from these three approaches we utilized quantitative PCR to compare the expression of candidate genes. Importantly, our data support consistent differences in discordant twins and siblings for the (i) methylation profiles of 60 gene regions, (ii) CNV of 10 genes, and (iii) the expression of 2 interferon-dependent genes. Quantitative PCR analysis showed that 17 of these genes are differentially expressed in discordant sibling pairs. In conclusion, we report that MZ twins and sisters discordant for PBC manifest particular epigenetic differences and highlight the value of the epigenetic study of twins. PMID:24734033

  18. The Trend of CEACAM3 Blood Expression as Number Index of the CTCs in the Colorectal Cancer Perioperative Course

    PubMed Central

    Taddei, A.; Castiglione, F.; Ringressi, M. N.; Niccolai, E.; Tofani, L.; Boni, L.; Bechi, P.; Amedei, A.

    2015-01-01

    Pathological stage seems to be the major determinant of postoperative prognosis of solid tumors, but additional prognostic determinants need to be better investigated. The most important tumor marker for colorectal cancer (CRC) is the cell-surface antigen, Carcinoembryonic Antigen (CEA), and its assessment is considered a valuable index of circulating tumor cells (CTCs). In this paper, CEACAM3 evaluation was applied given its great specificity in the CRC. Whole blood from the basilic vein of 38 CRC patients was collected before and at various time intervals after the curative resection. Also, from 20 of them, we have obtained two additional intraoperative samples. CEACAM3 expression was evaluated in all the samples by RT-PCR. CEACAM3 duct values showed a decreasing trend from preoperative through early and later postoperative to 6th-month samples (p < 0.001). The average values of CEACAM3 were related to the cancer size (T stage) (p = 0.034) and WHO stage (p = 0.035). A significant effect of the baseline value of CEACAM3 dCt on the temporal trend has been observed (p < 0.001). In this study, we have demonstrated the CEACAM3 specificity and a perioperative trend of CTCs which is coherent with the clinical/pathological considerations and with previous experimental findings in different cancer types. PMID:26556959

  19. Effect of aflatoxin B₁ on IgA⁺ cell number and immunoglobulin mRNA expression in the intestine of broilers.

    PubMed

    Jiang, Min; Fang, Jing; Peng, Xi; Cui, Hengmin; Yu, Zhengqiang

    2015-01-01

    Aflatoxin B1 (AFB1) is the most toxic group of mycotoxins produced by two species of the Aspergillus, common contaminants of food and animal feed. The purpose of our study was to determine the effect of AFB1 on the number of IgA(+) cell and immunoglobulin mRNA expression in the intestine of broilers. One hundred and fifty six one-day-old healthy Cobb broilers were randomly divided into the control group (the dosage of 0 mg/kg AFB1) and AFB1 group (the dosage of 0.6 mg/kg AFB1) with three replicates per group and 26 birds per replicate for 21 days, respectively. After necropsy at 7, 14 and 21 days of age, duodenum, jejunum and ileum samples were taken for analyzing IgA(+) cell by immunohistochemistry and IgA, pIgR, IgM and IgG mRNA expression by qRT-PCR. IgA(+) cells were mainly distributed in the lamina propria of small intestinal mucosa in both groups at 14 and 21 days of age. A significant decrease in the number of IgA(+) cells in the duodenum, jejunum and ileum was revealed in the AFB1 group compared with that of the control group. The expression levels of IgA, pIgR, IgM and IgG mRNA in the intestinal mucosa were lower in the AFB1 group than those in the control group at 14 and 21 days of age. Our data demonstrated that the dosage of 0.6 mg/kg AFB1 in broiler diet reduced the number of IgA(+) cell and the expression of IgA, pIgR, IgM and IgG mRNA in the small intestine.

  20. Age-Dependent Brain Gene Expression and Copy Number Anomalies in Autism Suggest Distinct Pathological Processes at Young Versus Mature Ages

    PubMed Central

    Winn, Mary E.; Barnes, Cynthia Carter; Li, Hai-Ri; Weiss, Lauren; Fan, Jian-Bing; Murray, Sarah; April, Craig; Belinson, Haim; Fu, Xiang-Dong; Wynshaw-Boris, Anthony; Schork, Nicholas J.; Courchesne, Eric

    2012-01-01

    Autism is a highly heritable neurodevelopmental disorder, yet the genetic underpinnings of the disorder are largely unknown. Aberrant brain overgrowth is a well-replicated observation in the autism literature; but association, linkage, and expression studies have not identified genetic factors that explain this trajectory. Few studies have had sufficient statistical power to investigate whole-genome gene expression and genotypic variation in the autistic brain, especially in regions that display the greatest growth abnormality. Previous functional genomic studies have identified possible alterations in transcript levels of genes related to neurodevelopment and immune function. Thus, there is a need for genetic studies involving key brain regions to replicate these findings and solidify the role of particular functional pathways in autism pathogenesis. We therefore sought to identify abnormal brain gene expression patterns via whole-genome analysis of mRNA levels and copy number variations (CNVs) in autistic and control postmortem brain samples. We focused on prefrontal cortex tissue where excess neuron numbers and cortical overgrowth are pronounced in the majority of autism cases. We found evidence for dysregulation in pathways governing cell number, cortical patterning, and differentiation in young autistic prefrontal cortex. In contrast, adult autistic prefrontal cortex showed dysregulation of signaling and repair pathways. Genes regulating cell cycle also exhibited autism-specific CNVs in DNA derived from prefrontal cortex, and these genes were significantly associated with autism in genome-wide association study datasets. Our results suggest that CNVs and age-dependent gene expression changes in autism may reflect distinct pathological processes in the developing versus the mature autistic prefrontal cortex. Our results raise the hypothesis that genetic dysregulation in the developing brain leads to abnormal regional patterning, excess prefrontal neurons

  1. Increase in peroxisome number and the gene expression of putative glyoxysomal enzymes in Chlamydomonas cells supplemented with acetate.

    PubMed

    Hayashi, Yasuko; Sato, Nagisa; Shinozaki, Akiko; Watanabe, Mariko

    2015-01-01

    We cultured Chlamydomonas reinhardtii cells in a minimal culture medium supplemented with various concentrations of acetate, fatty acids, ethanol, fatty alcohols, or sucrose. The presence of acetate (0.5 or 1.0%, w/v) was advantageous for cell growth. To determine whether peroxisomes are involved in fatty acid and fatty alcohol metabolism, we investigated the dynamics of peroxisomes, including changes in their number and size, in the presence of acetate, ethanol, and sucrose. The total volume of peroxisomes increased when cells were grown with acetate, but did not change when cells were grown with ethanol or sucrose. We analyzed cell growth on minimal culture medium supplemented with various fatty acids (carbon chain length ranging from one to ten) to investigate which fatty acids are metabolized by C. reinhardtii. Among them, acetate caused the greatest increase in growth when added to minimal culture media. We analyzed the transcript levels of genes encoding putative glyoxysomal enzymes. The transcript levels of genes encoding malate synthase, malate dehydrogenase, isocitrate lyase, and citrate synthase increased when Chlamydomonas cells were grown on minimal culture medium supplemented with acetate. Our results suggest that Chlamydomonas peroxisomes are involved in acetate metabolism via the glyoxylate cycle.

  2. Mesodermal Gene Expression in the Acoel Isodiametra pulchra Indicates a Low Number of Mesodermal Cell Types and the Endomesodermal Origin of the Gonads

    PubMed Central

    Chiodin, Marta; Børve, Aina; Berezikov, Eugene; Ladurner, Peter; Martinez, Pedro; Hejnol, Andreas

    2013-01-01

    Acoelomorphs are bilaterally symmetric small marine worms that lack a coelom and possess a digestive system with a single opening. Two alternative phylogenetic positions of this group within the animal tree are currently debated. In one view, Acoelomorpha is the sister group to all remaining Bilateria and as such, is a morphologically simple stepping stone in bilaterian evolution. In the other, the group is a lineage within the Deuterostomia, and therefore, has derived a simple morphology from a more complex ancestor. Acoels and the closely related Nemertodermatida and Xenoturbellida, which together form the Acoelomorpha, possess a very limited number of cell types. To further investigate the diversity and origin of mesodermal cell types we describe the expression pattern of 12 orthologs of bilaterian mesodermal markers including Six1/2, Twist, FoxC, GATA4/5/6, in the acoel Isodiametra pulchra. All the genes are expressed in stem cells (neoblasts), gonads, and at least subsets of the acoel musculature. Most are expressed in endomesodermal compartments of I. pulchra developing embryos similar to what has been described in cnidarians. Our molecular evidence indicates a very limited number of mesodermal cell types and suggests an endomesodermal origin of the gonads and the stem cell system. We discuss our results in light of the two prevailing phylogenetic positions of Acoelomorpha. PMID:23405161

  3. Kif3a controls murine nephron number via GLI3 repressor, cell survival, and gene expression in a lineage-specific manner.

    PubMed

    Chi, Lijun; Galtseva, Alevtina; Chen, Lin; Mo, Rong; Hui, Chi-Chung; Rosenblum, Norman D

    2013-01-01

    The primary cilium is required during early embryo patterning, epithelial tubulogenesis, and growth factor-dependent signal transduction. The requirement for primary cilia during renal epithelial-mesenchymal tissue interactions that give rise to nephrons is undefined. Here, we used Cre-mediated recombination to generate mice with Kif3a deficiency targeted to the ureteric and/or metanephric mesenchyme cell lineages in the embryonic kidney. Gradual loss of primary cilia in either lineage leads to a phenotype of reduced nephron number. Remarkably, in addition to cyst formation, loss of primary cilia in the ureteric epithelial cell leads to decreased expression of Wnt11 and Ret and reduced ureteric branching. Constitutive expression of GLI3 repressor (Gli3(Δ699/+) ) rescues these abnormalities. In embryonic metanephric mesenchyme cells, Kif3a deficiency limits survival of nephrogenic progenitor cells and expression of genes required for nephron formation. Together, our data demonstrate that Kif3a controls nephron number via distinct cell lineage-specific mechanisms.

  4. Cell Cycle- and Ribonucleotide Reductase-Driven Changes in mtDNA Copy Number Influence mtDNA Inheritance Without Compromising Mitochondrial Gene Expression

    PubMed Central

    Lebedeva, Maria A.; Shadel, Gerald S.

    2008-01-01

    Most eukaryotes maintain multiple copies of mtDNA, ranging from 20–50 in yeast to as many as 10,000 in mammalian cells. The mitochondrial genome encodes essential subunits of the respiratory chain, but the number of mtDNA molecules is apparently in excess of that needed to sustain adequate respiration, as evidenced by the “threshold effect” in mitochondrial diseases. Thus, other selective pressures apparently have contributed to the universal maintenance of multiple mtDNA molecules/cell. Here we analyzed the interplay between the two pathways proposed to regulate mtDNA copy number in Saccharomyces cerevisiae, and the requirement of normal mtDNA copy number for mitochondrial gene expression, respiration, and inheritance. We provide the first direct evidence that upregulation of mtDNA can be achieved by increasing ribonucleotide reductase (RNR) activity via derepression of nuclear RNR gene transcription or elimination of allosteric-feedback regulation. Analysis of rad53 mutant strains also revealed upregulation of mtDNA copy number independent of that resulting from elevated RNR activity. We present evidence that a prolonged cell cycle allows accumulation of mtDNA in these strains. Analysis of multiple strains with increased or decreased mtDNA revealed that mechanisms are in place to prevent significant changes in mitochondrial gene expression and respiration in the face of ∼two-fold alterations in mtDNA copy number. However, depletion of mtDNA in abf2 null strains leads to defective mtDNA inheritance that is partially rescued by replenishing mtDNA via overexpression of RNR1. These results indicate that one role for multiple mtDNA copies is to ensure optimal inheritance of mtDNA during cell division. PMID:17721079

  5. Decreased number of CD4{sup +} and CD8{sup +} T cells that express the interleukin-7 receptor in blood and tissues of SIV-infected macaques

    SciTech Connect

    Moniuszko, Marcin; Edghill-Smith, Yvette; Stevceva, Liljana; Tsai, Wen-Po . E-mail: franchig@mail.nih.gov

    2006-12-20

    Acute HIV/SIV (human/simian immunodeficiency virus) infection results in severe CD4{sup +} T cell depletion in lymphoid compartments. During the chronic phase of infection, CD4{sup +} T cell numbers rebound in blood but remain low in the gut-associated lymphoid tissue (GALT), even when viral replication is suppressed by antiretroviral therapy (ART). Thus, strategies to repopulate lymphoid compartments may ameliorate the clinical outcome of HIV/SIV infection. Interleukin (IL)-7 is a key cytokine for the maintenance of homeostatic proliferation of T cells. In HIV/SIV infection, IL-7 expression is increased, likely to compensate for T cell loss, suggesting that supraphysiological administration of IL-7 could provide additional benefit. However, the ability of T cells to respond to IL-7 is dependent on the level of expression of the IL-7 receptor (IL-7R) in T cells in various body compartments. In here, we investigated the proportion of IL-7R{sup +} T cells in blood, spleen, gut, and genitourinary tract of healthy and SIV-infected macaques with various degrees of CD4{sup +} T cell depletion. We found that the percentage of T cells expressing IL-7R was significantly lower in both CD4{sup +} and CD8{sup +} T cell subsets in SIV-infected macaques than in healthy animals and this decrease directly correlated with the CD4{sup +} T cell number. Importantly, the proportion of CD4{sup +} and CD8{sup +} T cells expressing IL-7R in blood paralleled that found in tissues. IL-7R{sup +} T cells within the SIV-specific CD8{sup +} T cells varied and were lowest in most tissues of viremic macaques, likely reflecting continuous antigen stimulation of effector cells.

  6. Probiotic Treatment Decreases the Number of CD14-Expressing Cells in Porcine Milk Which Correlates with Several Intestinal Immune Parameters in the Piglets

    PubMed Central

    Scharek-Tedin, Lydia; Kreuzer-Redmer, Susanne; Twardziok, Sven Olaf; Siepert, Bianca; Klopfleisch, Robert; Tedin, Karsten; Zentek, Jürgen; Pieper, Robert

    2015-01-01

    Modulating the mucosal immune system of neonates by probiotic treatment of their mothers is a promising approach which can only be investigated through the use of animal models. Here, we used sows and their piglets to investigate the impact of a bacterial treatment on the sow’s milk and on the neonate piglet intestinal immune system. In previous experiments, feed supplementation of sows with the probiotic Enterococcus faecium NCIMB 10415 during pregnancy and lactation had been shown to affect intestinal microbiota and cytokine expression of the offspring during the suckling and weaning periods. We therefore investigated the composition of the milk from treated sows in comparison to samples from a control group. In treated sows, the amount of lactose increased, and the somatic cell numbers were reduced. In all milk samples, the percentage of cells expressing membranous CD14 (mCD14) was greater than the fractions of immune cells, indicating expression of mCD14 on mammary epithelial cells. However, in the milk of E. faecium-treated sows, mCD14+ cells were reduced. Furthermore, the number of CD14+ milk cells was positively correlated with the percentages of B cells and activated T cells in the ileal MLN of the piglets. This study provides evidence for the expression of mCD14 by the porcine mammary epithelium, and suggests an immunological effect of mCD14+ milk cells on the piglets’ intestinal immune system. Our study further suggests that mCD14+ mammary epithelial cell populations can be modulated by probiotic feed supplementation of the sow. PMID:25806034

  7. Gene expression analysis of human induced pluripotent stem cell-derived neurons carrying copy number variants of chromosome 15q11-q13.1

    PubMed Central

    2014-01-01

    Background Duplications of the chromosome 15q11-q13.1 region are associated with an estimated 1 to 3% of all autism cases, making this copy number variation (CNV) one of the most frequent chromosome abnormalities associated with autism spectrum disorder (ASD). Several genes located within the 15q11-q13.1 duplication region including ubiquitin protein ligase E3A (UBE3A), the gene disrupted in Angelman syndrome (AS), are involved in neural function and may play important roles in the neurobehavioral phenotypes associated with chromosome 15q11-q13.1 duplication (Dup15q) syndrome. Methods We have generated induced pluripotent stem cell (iPSC) lines from five different individuals containing CNVs of 15q11-q13.1. The iPSC lines were differentiated into mature, functional neurons. Gene expression across the 15q11-q13.1 locus was compared among the five iPSC lines and corresponding iPSC-derived neurons using quantitative reverse transcription PCR (qRT-PCR). Genome-wide gene expression was compared between neurons derived from three iPSC lines using mRNA-Seq. Results Analysis of 15q11-q13.1 gene expression in neurons derived from Dup15q iPSCs reveals that gene copy number does not consistently predict expression levels in cells with interstitial duplications of 15q11-q13.1. mRNA-Seq experiments show that there is substantial overlap in the genes differentially expressed between 15q11-q13.1 deletion and duplication neurons, Finally, we demonstrate that UBE3A transcripts can be pharmacologically rescued to normal levels in iPSC-derived neurons with a 15q11-q13.1 duplication. Conclusions Chromatin structure may influence gene expression across the 15q11-q13.1 region in neurons. Genome-wide analyses suggest that common neuronal pathways may be disrupted in both the Angelman and Dup15q syndromes. These data demonstrate that our disease-specific stem cell models provide a new tool to decipher the underlying cellular and genetic disease mechanisms of ASD and may also offer a

  8. Ectopic expression of the Brassica SHOOTMERISTEMLESS attenuates the deleterious effects of the auxin transport inhibitor TIBA on somatic embryo number and morphology.

    PubMed

    Elhiti, Mohamed; Stasolla, Claudio

    2011-02-01

    The auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) is a useful compound for investigating the role of auxin flow during plant growth and development. In Arabidopsis lines, applications of TIBA during the induction phase of somatic embryogenesis inhibit embryo development and induce the differentiation of the meristematic cells of the shoot apical meristem (SAM), leading to the fusion of the cotyledons. These abnormalities were associated to changes in the expression levels of auxin transporter genes (PINs) and endogenous distribution of IAA. Treatments of TIBA caused a rapid accumulation of IAA within the epidermal and cortical root cells of the explants (bent-cotyledon zygotic embryos), as well as in the apical and sub-apical cells of the callus generated by the surface of the cotyledons of the explants. Within the callus only a few cells acquired meristematic characteristics, and this was associated to low expression levels of genes involved in embryogenic cell fate acquisition, such as WUSCHEL (WUS), LEAFY COTYLEDON 1 and 2. All these deleterious effects were attenuated when TIBA was administered to lines over-expressing SHOOT MERISTEMLESS (STM) isolated from Brassica oleracea (Bo), B. napus (Bn), and B. rapa (Br). Of interest, TIBA-treated explants of Arabidopsis lines over-expressing the Brassica STM were able to produce a large number of embryogenic cells and somatic embryos which exhibited a normal morphology and two distinct cotyledons. A proposed reason for this behaviour was ascribed to the ability of the transformed tissue to retain a normal distribution of auxin in the presence of TIBA. Proper localization of auxin might be required for the normal expression of several genes needed for the acquisition of embryogenic competence and formation of somatic embryos.

  9. Ectopic expression of the Brassica SHOOTMERISTEMLESS attenuates the deleterious effects of the auxin transport inhibitor TIBA on somatic embryo number and morphology.

    PubMed

    Elhiti, Mohamed; Stasolla, Claudio

    2011-02-01

    The auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) is a useful compound for investigating the role of auxin flow during plant growth and development. In Arabidopsis lines, applications of TIBA during the induction phase of somatic embryogenesis inhibit embryo development and induce the differentiation of the meristematic cells of the shoot apical meristem (SAM), leading to the fusion of the cotyledons. These abnormalities were associated to changes in the expression levels of auxin transporter genes (PINs) and endogenous distribution of IAA. Treatments of TIBA caused a rapid accumulation of IAA within the epidermal and cortical root cells of the explants (bent-cotyledon zygotic embryos), as well as in the apical and sub-apical cells of the callus generated by the surface of the cotyledons of the explants. Within the callus only a few cells acquired meristematic characteristics, and this was associated to low expression levels of genes involved in embryogenic cell fate acquisition, such as WUSCHEL (WUS), LEAFY COTYLEDON 1 and 2. All these deleterious effects were attenuated when TIBA was administered to lines over-expressing SHOOT MERISTEMLESS (STM) isolated from Brassica oleracea (Bo), B. napus (Bn), and B. rapa (Br). Of interest, TIBA-treated explants of Arabidopsis lines over-expressing the Brassica STM were able to produce a large number of embryogenic cells and somatic embryos which exhibited a normal morphology and two distinct cotyledons. A proposed reason for this behaviour was ascribed to the ability of the transformed tissue to retain a normal distribution of auxin in the presence of TIBA. Proper localization of auxin might be required for the normal expression of several genes needed for the acquisition of embryogenic competence and formation of somatic embryos. PMID:21421384

  10. Combined analysis of gene expression, DNA copy number, and mutation profiling data to display biological process anomalies in individual breast cancers.

    PubMed

    Shi, Weiwei; Balazs, Balint; Györffy, Balazs; Jiang, Tingting; Symmans, W Fraser; Hatzis, Christos; Pusztai, Lajos

    2014-04-01

    The goal of this analysis was to develop a computational tool that integrates the totality of gene expression, DNA copy number, and sequence abnormalities in individual cancers in the framework of biological processes. We used the hierarchical structure of the gene ontology (GO) database to create a reference network and projected mRNA expression, DNA copy number and mutation anomalies detected in single samples into this space. We applied our method to 59 breast cancers where all three types of molecular data were available. Each cancer had a large number of disturbed biological processes. Locomotion, multicellular organismal process, and signal transduction pathways were the most commonly affected GO terms, but the individual molecular events were different from case-to-case. Estrogen receptor-positive and -negative cancers had different repertoire of anomalies. We tested the functional impact of 27 mRNAs that had overexpression in cancer with variable frequency (<2-42 %) using an siRNA screen. Each of these genes inhibited cell growth in at least some of 18 breast cancer cell lines. We developed a free, on-line software tool ( http://netgoplot.org ) to display the complex genomic abnormalities in individual cancers in the biological framework of the GO biological processes. Each cancer harbored a variable number of pathway anomalies and the individual molecular events that caused an anomaly varied from case-to-case. Our in vitro experiments indicate that rare case-specific molecular abnormalities can play a functional role and driver events may vary from case-to-case depending on the constellation of other molecular anomalies.

  11. Porcine MAP3K5 analysis: molecular cloning, characterization, tissue expression pattern, and copy number variations associated with residual feed intake.

    PubMed

    Pu, L; Zhang, L C; Zhang, J S; Song, X; Wang, L G; Liang, J; Zhang, Y B; Liu, X; Yan, H; Zhang, T; Yue, J W; Li, N; Wu, Q Q; Wang, L X

    2016-01-01

    Mitogen-activated protein kinase kinase kinase 5 (MAP3K5) is essential for apoptosis, proliferation, differentiation, and immune responses, and is a candidate marker for residual feed intake (RFI) in pig. We cloned the full-length cDNA sequence of porcine MAP3K5 by rapid-amplification of cDNA ends. The 5451-bp gene contains a 5'-untranslated region (UTR) (718 bp), a coding region (3738 bp), and a 3'-UTR (995 bp), and encodes a peptide of 1245 amino acids, which shares 97, 99, 97, 93, 91, and 84% sequence identity with cattle, sheep, human, mouse, chicken, and zebrafish MAP3K5, respectively. The deduced MAP3K5 protein sequence contains two conserved domains: a DUF4071 domain and a protein kinase domain. Phylogenetic analysis showed that porcine MAP3K5 forms a separate branch to vicugna and camel MAP3K5. Tissue expression analysis using real-time quantitative polymerase chain reaction (qRT-PCR) revealed that MAP3K5 was expressed in the heart, liver, spleen, lung, kidney, muscle, fat, pancrea, ileum, and stomach tissues. Copy number variation was detected for porcine MAP3K5 and validated by qRT-PCR. Furthermore, a significant increase in average copy number was detected in the low RFI group when compared to the high RFI group in a Duroc pig population. These results provide useful information regarding the influence of MAP3K5 on RFI in pigs. PMID:27525933

  12. Quality improvement of transgenic cloned bovine embryos using an aggregation method: Effects on cell number, cell ratio, embryo perimeter, mitochondrial distribution, and gene expression profile.

    PubMed

    Bang, J I; Jin, J I; Ghanem, N; Choi, B H; Fakruzzaman, M; Ha, A N; Lee, K L; Uhm, S J; Ko, D H; Koo, B C; Lee, J G; Kong, I K

    2015-09-01

    The production of cloned embryos using conventional methods has extremely low success rates owing to low embryo quality. To improve the quality of cloned bovine embryos expressing enhanced green fluorescent protein (EGFP), we applied an aggregation culture method. The EGFP gene was transfected into bovine fetal fibroblasts using a retroviral vector system. Somatic cell nuclear transfer was performed using these cells, and the resulting embryos were cultured in aggregates or individually. Gene expression was analyzed by a microarray, and differentially expressed genes were validated by quantitative real-time polymerase chain reaction. The total number of cells per blastocyst and the ratio of inner cell mass cells to trophectoderm cells were higher in aggregated transgenic cloned blastocysts (agBL; 368.7 ± 109.6 and 1:4.8, respectively) than in in vitro-fertilized blastocysts (ivfBL; 189.8 ± 65.8 and 1:2.6, respectively) and nonaggregated transgenic cloned blastocysts (sBL; 113.1 ± 36.3 and 1:1.5, respectively; P < 0.05 and P < 0.01, respectively). Moreover, the blastocyst perimeter was larger in the agBL group than in the ivfBL and sBL groups (1168.8 ± 200.23 vs. 887.33 ± 187.62 and 678 ± 226.1 μm; P < 0.05). In addition, mitochondrial fluorescence intensity was higher in the agBL group than in the ivfBL and sBL groups (P < 0.05). The number of apoptotic cells per blastocyst was lower in the ivfBL and agBL groups than in the sBL group (3.7 ± 2.2 and 3.4 ± 2.1 vs. 6.7 ± 6.8; P < 0.05). The genes identified in the microarray belonged to 18 categories. Expression of the Krüppel-like factor 4 gene, which is associated with cell proliferation, development, and transcription, was 7.2-fold higher in the agBL group than in the ivfBL group (P < 0.05) but did not differ between the sBL and ivfBL groups (P > 0.05). Expression of the heat shock 70-kDa protein 1A gene, which is associated with apoptosis, was 12-fold higher in the s

  13. Linear correlation between the number of olfactory sensory neurons expressing a given mouse odorant receptor gene and the total volume of the corresponding glomeruli in the olfactory bulb

    PubMed Central

    Bressel, Olaf Christian; Khan, Mona

    2015-01-01

    ABSTRACT Chemosensory specificity in the main olfactory system of the mouse relies on the expression of ∼1,100 odorant receptor (OR) genes across millions of olfactory sensory neurons (OSNs) in the main olfactory epithelium (MOE), and on the coalescence of OSN axons into ∼3,600 glomeruli in the olfactory bulb. A traditional approach for visualizing OSNs and their axons consists of tagging an OR gene genetically with an axonal marker that is cotranslated with the OR by virtue of an internal ribosome entry site (IRES). Here we report full cell counts for 15 gene‐targeted strains of the OR‐IRES‐marker design coexpressing a fluorescent protein. These strains represent 11 targeted OR genes, a 1% sample of the OR gene repertoire. We took an empirical, “count every cell” strategy: we counted all fluorescent cell profiles with a nuclear profile within the cytoplasm, on all serial coronal sections under a confocal microscope, a total of 685,673 cells in 56 mice at postnatal day 21. We then applied a strain‐specific Abercrombie correction to these OSN counts in order to obtain a closer approximation of the true OSN numbers. We found a 17‐fold range in the average (corrected) OSN number across these 11 OR genes. In the same series of coronal sections, we then determined the total volume of the glomeruli (TGV) formed by coalescence of the fluorescent axons. We found a strong linear correlation between OSN number and TGV, suggesting that TGV can be used as a surrogate measurement for estimating OSN numbers in these gene‐targeted strains. J. Comp. Neurol. 524:199–209, 2016. © 2015 Wiley Periodicals, Inc. PMID:26100963

  14. A human sleep homeostasis phenotype in mice expressing a primate-specific PER3 variable-number tandem-repeat coding-region polymorphism.

    PubMed

    Hasan, Sibah; van der Veen, Daan R; Winsky-Sommerer, Raphaelle; Hogben, Alexandra; Laing, Emma E; Koentgen, Frank; Dijk, Derk-Jan; Archer, Simon N

    2014-06-01

    In humans, a primate-specific variable-number tandem-repeat (VNTR) polymorphism (4 or 5 repeats 54 nt in length) in the circadian gene PER3 is associated with differences in sleep timing and homeostatic responses to sleep loss. We investigated the effects of this polymorphism on circadian rhythmicity and sleep homeostasis by introducing the polymorphism into mice and assessing circadian and sleep parameters at baseline and during and after 12 h of sleep deprivation (SD). Microarray analysis was used to measure hypothalamic and cortical gene expression. Circadian behavior and sleep were normal at baseline. The response to SD of 2 electrophysiological markers of sleep homeostasis, electroencephalography (EEG) θ power during wakefulness and δ power during sleep, were greater in the Per3(5/5) mice. During recovery, the Per3(5/5) mice fully compensated for the SD-induced deficit in δ power, but the Per3(4/4) and wild-type mice did not. Sleep homeostasis-related transcripts (e.g., Homer1, Ptgs2, and Kcna2) were differentially expressed between the humanized mice, but circadian clock genes were not. These data are in accordance with the hypothesis derived from human data that the PER3 VNTR polymorphism modifies the sleep homeostatic response without significantly influencing circadian parameters.

  15. Dimensionless parameterization of lidar for laser remote sensing of the atmosphere and its application to systems with SiPM and PMT detectors.

    PubMed

    Agishev, Ravil; Comerón, Adolfo; Rodriguez, Alejandro; Sicard, Michaël

    2014-05-20

    In this paper, we show a renewed approach to the generalized methodology for atmospheric lidar assessment, which uses the dimensionless parameterization as a core component. It is based on a series of our previous works where the problem of universal parameterization over many lidar technologies were described and analyzed from different points of view. The modernized dimensionless parameterization concept applied to relatively new silicon photomultiplier detectors (SiPMs) and traditional photomultiplier (PMT) detectors for remote-sensing instruments allowed predicting the lidar receiver performance with sky background available. The renewed approach can be widely used to evaluate a broad range of lidar system capabilities for a variety of lidar remote-sensing applications as well as to serve as a basis for selection of appropriate lidar system parameters for a specific application. Such a modernized methodology provides a generalized, uniform, and objective approach for evaluation of a broad range of lidar types and systems (aerosol, Raman, DIAL) operating on different targets (backscatter or topographic) and under intense sky background conditions. It can be used within the lidar community to compare different lidar instruments. PMID:24922200

  16. Dimensionless parameterization of lidar for laser remote sensing of the atmosphere and its application to systems with SiPM and PMT detectors.

    PubMed

    Agishev, Ravil; Comerón, Adolfo; Rodriguez, Alejandro; Sicard, Michaël

    2014-05-20

    In this paper, we show a renewed approach to the generalized methodology for atmospheric lidar assessment, which uses the dimensionless parameterization as a core component. It is based on a series of our previous works where the problem of universal parameterization over many lidar technologies were described and analyzed from different points of view. The modernized dimensionless parameterization concept applied to relatively new silicon photomultiplier detectors (SiPMs) and traditional photomultiplier (PMT) detectors for remote-sensing instruments allowed predicting the lidar receiver performance with sky background available. The renewed approach can be widely used to evaluate a broad range of lidar system capabilities for a variety of lidar remote-sensing applications as well as to serve as a basis for selection of appropriate lidar system parameters for a specific application. Such a modernized methodology provides a generalized, uniform, and objective approach for evaluation of a broad range of lidar types and systems (aerosol, Raman, DIAL) operating on different targets (backscatter or topographic) and under intense sky background conditions. It can be used within the lidar community to compare different lidar instruments.

  17. Relativistic theory of tidal Love numbers

    SciTech Connect

    Binnington, Taylor; Poisson, Eric

    2009-10-15

    In Newtonian gravitational theory, a tidal Love number relates the mass multipole moment created by tidal forces on a spherical body to the applied tidal field. The Love number is dimensionless, and it encodes information about the body's internal structure. We present a relativistic theory of Love numbers, which applies to compact bodies with strong internal gravities; the theory extends and completes a recent work by Flanagan and Hinderer, which revealed that the tidal Love number of a neutron star can be measured by Earth-based gravitational-wave detectors. We consider a spherical body deformed by an external tidal field, and provide precise and meaningful definitions for electric-type and magnetic-type Love numbers; and these are computed for polytropic equations of state. The theory applies to black holes as well, and we find that the relativistic Love numbers of a nonrotating black hole are all zero.

  18. Express

    Integrated Risk Information System (IRIS)

    Express ; CASRN 101200 - 48 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  19. Genome-wide screening of copy number alterations and LOH events in renal cell carcinomas and integration with gene expression profile

    PubMed Central

    Cifola, Ingrid; Spinelli, Roberta; Beltrame, Luca; Peano, Clelia; Fasoli, Ester; Ferrero, Stefano; Bosari, Silvano; Signorini, Stefano; Rocco, Francesco; Perego, Roberto; Proserpio, Vanessa; Raimondo, Francesca; Mocarelli, Paolo; Battaglia, Cristina

    2008-01-01

    Background Clear cell renal carcinoma (RCC) is the most common and invasive adult renal cancer. For the purpose of identifying RCC biomarkers, we investigated chromosomal regions and individual genes modulated in RCC pathology. We applied the dual strategy of assessing and integrating genomic and transcriptomic data, today considered the most effective approach for understanding genetic mechanisms of cancer and the most sensitive for identifying cancer-related genes. Results We performed the first integrated analysis of DNA and RNA profiles of RCC samples using Affymetrix technology. Using 100K SNP mapping arrays, we assembled a genome-wide map of DNA copy number alterations and LOH areas. We thus confirmed the typical genetic signature of RCC but also identified other amplified regions (e.g. on chr. 4, 11, 12), deleted regions (chr. 1, 9, 22) and LOH areas (chr. 1, 2, 9, 13). Simultaneously, using HG-U133 Plus 2.0 arrays, we identified differentially expressed genes (DEGs) in tumor vs. normal samples. Combining genomic and transcriptomic data, we identified 71 DEGs in aberrant chromosomal regions and observed, in amplified regions, a predominance of up-regulated genes (27 of 37 DEGs) and a trend to clustering. Functional annotation of these genes revealed some already implicated in RCC pathology and other cancers, as well as others that may be novel tumor biomarkers. Conclusion By combining genomic and transcriptomic profiles from a collection of RCC samples, we identified specific genomic regions with concordant alterations in DNA and RNA profiles and focused on regions with increased DNA copy number. Since the transcriptional modulation of up-regulated genes in amplified regions may be attributed to the genomic alterations characteristic of RCC, these genes may encode novel RCC biomarkers actively involved in tumor initiation and progression and useful in clinical applications. PMID:18194544

  20. Series of Reciprocal Triangular Numbers

    ERIC Educational Resources Information Center

    Bruckman, Paul; Dence, Joseph B.; Dence, Thomas P.; Young, Justin

    2013-01-01

    Reciprocal triangular numbers have appeared in series since the very first infinite series were summed. Here we attack a number of subseries of the reciprocal triangular numbers by methodically expressing them as integrals.

  1. Leftist Numbers

    ERIC Educational Resources Information Center

    Rich, Andrew

    2008-01-01

    The leftist number system consists of numbers with decimal digits arranged in strings to the left, instead of to the right. This system fails to be a field only because it contains zerodivisors. The same construction with prime base yields the p-adic numbers.

  2. Number Time

    ERIC Educational Resources Information Center

    Herrera, Terese A.

    2004-01-01

    This article features Number Time, a site developed by the British Broadcasting Corporation (BBC) for young mathematics learners, located at www.bbc.co.uk/schools/numbertime. The site uses interactive animation to help children in pre-K through grade 2 understand and practice number basics. Users will find online games, videos that tell number…

  3. Influence of the Prandtl number on the heat transport enhancement in rotating turbulent Rayleigh-Bénard convection

    NASA Astrophysics Data System (ADS)

    Weiss, Stephan; Wei, Ping; Ahlers, Guenter

    2014-11-01

    We present new Nusselt-number (Nu) measurements for slowly rotating turbulent thermal convection in cylinders with aspect ratio Γ = 1 . By using compressed gasses and various liquids, we now have data in the Prandtl number (Pr) range 0 . 74 < Pr < 35 . 5 and for Rayleigh numbers (Ra) in the range 4 ×108 < Ra < 2 ×1011 . With these data we investigate in detail the effect of Pr and Ra on the heat-transport enhancement close to its onset. This enhancement takes place for rotation rates larger than a critical value, as expressed by the dimensionless inverse Rossby number (1 / Ro), since only then vortices form, in which due to Ekman pumping fluid is transported from the thermal boundary layers into the turbulent bulk. We found that the critical inverse Rossby number (1 / Roc) decreases with increasing Pr, following a power law with exponent α = - 0 . 40 +/- 0 . 02 . For larger rotation rates, the relative heat transport enhancement (Nur) increases first linearly with a slope S = ∂Nur / ∂ (1 / Ro) . We show that also the slope S follows a power law S ~ Prβ Raγ with β = - 0 . 10 +/- 0 . 06 and γ = - 0 . 14 +/- 0 . 04 . We found that the maximum heat transport enhancement (up to 40%) increases with increasing Pr and decreasing Ra. This work was supported by NSF-Grant DMR11-58514. SW thanks the Deutsche Forschungsgesellschaft for financial support.

  4. Consequences of Growth Media, Gene Copy Number, and Regulatory Mutations on the Expression of the Prb1 Gene of Saccharomyces Cerevisiae

    PubMed Central

    Moehle, C. M.; Jones, E. W.

    1990-01-01

    Glucose represses PRB1 expression at the level of transcription. However, release from glucose repression initially does not result in accumulation of protease B (PrB) activity despite transcriptional derepression. PrB activity accumulates only upon a second transcriptional derepression as the cells approach stationary phase. Increasing the PRB1 gene dosage on 2μ-based plasmids does not overcome glucose repression. Glucose-mediated repression of PRB1 is not subject to the same genetic controls as SUC2. Mutation of the HXK2 gene, which confers glucose-insensitive expression of secreted invertase, had no effect on PRB1 expression at the level of PrB activity. Strains bearing a mutation in any of the SNF1-SNF6 genes cannot derepress secreted invertase synthesis, but did derepress PrB synthesis when grown in the absence of glucose. Mutation of the SNF2 or SNF5 gene led to accumulation of PrB activity to levels ten times that of wild type. Polymorphism for a suppressor gene was observed: in snf5-bearing strains, one allele of this suppressor gene resulted in elevated levels of PrB and the other allele resulted in wild-type levels of PrB; neither allele suppressed the Suc(-) phenotype of the snf5 mutant. Re-examination of published data on SUC2 expression in snf2 and snf5 mutants and examination of PRB1 expression in these mutants paradoxically suggest that the SNF2 and SNF5 gene products might act as negative regulators of gene expression. PMID:2407604

  5. RhoE deficiency alters postnatal subventricular zone development and the number of calbindin-expressing neurons in the olfactory bulb of mouse.

    PubMed

    Ballester-Lurbe, Begoña; González-Granero, Susana; Mocholí, Enric; Poch, Enric; García-Manzanares, María; Dierssen, Mara; Pérez-Roger, Ignacio; García-Verdugo, José M; Guasch, Rosa M; Terrado, José

    2015-11-01

    The subventricular zone represents an important reservoir of progenitor cells in the adult brain. Cells from the subventricular zone migrate along the rostral migratory stream and reach the olfactory bulb, where they originate different types of interneurons. In this work, we have analyzed the role of the small GTPase RhoE/Rnd3 in subventricular zone cell development using mice-lacking RhoE expression. Our results show that RhoE null mice display a remarkable postnatal broadening of the subventricular zone and caudal rostral migratory stream. This broadening was caused by an increase in progenitor proliferation, observed in the second postnatal week but not before, and by an altered migration of the cells, which appeared in disorganized cell arrangements that impaired the appropriate contact between cells in the rostral migratory stream. In addition, the thickness of the granule cell layer in the olfactory bulb was reduced, although the density of granule cells did not differ between wild-type and RhoE null mice. Finally, the lack of RhoE expression affected the olfactory glomeruli inducing a severe reduction of calbindin-expressing interneurons in the periglomerular layer. This was already evident in the newborns and even more pronounced 15 days later when RhoE null mice displayed 89% less cells than control mice. Our results indicate that RhoE has pleiotropic functions on subventricular cells because of its role in proliferation and tangential migration, affecting mainly the development of calbindin-expressing cells in the olfactory bulb.

  6. Genome-wide Copy Number Variation and Temporal Genes Expression Analysis in Marek's Disease-Resistant or -Susceptible Inbred Lines of Chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Viruses that cause cancers are a great threat to human and animal health. Marek’s disease (MD) in chickens is a lymphoproliferative disease caused by Marek’s disease virus (MDV). The over-expression of Hodgkin’s disease antigen in MD makes it an ideal model to study the progression mechanism of Hodg...

  7. Numbers Sense

    ERIC Educational Resources Information Center

    Kathotia, Vinay

    2009-01-01

    This article reports on work undertaken by schools as part of Qualifications and Curriculum Authority's (QCA's) "Engaging mathematics for all learners" project. The goal was to use in the classroom, materials and approaches from a Royal Institution (Ri) Year 10 master-class, "Number Sense", which was inspired by examples from Michael Blastland and…

  8. Numbers, Please!

    ERIC Educational Resources Information Center

    Thelin, John R.

    2013-01-01

    What topic would you choose if you had the luxury of writing forever? In this article, John Thelin provides his response: He would opt to write about the history of higher education in a way that relies on quantitative data. "Numbers, please!" is his research request in taking on a longitudinal study of colleges and universities over…

  9. Systematic Review of Micro-RNA Expression in Pre-Eclampsia Identifies a Number of Common Pathways Associated with the Disease

    PubMed Central

    Sheikh, Adam M.; Currie, Gemma; Delles, Christian

    2016-01-01

    Background Pre-eclampsia (PE) is a complex, multi-systemic condition of pregnancy which greatly impacts maternal and perinatal morbidity and mortality. MicroRNAs (miRs) are differentially expressed in PE and may be important in helping to understand the condition and its pathogenesis. Methods Case-control studies investigating expression of miRs in PE were collected through a systematic literature search. Data was extracted and compared from 58 studies to identify the most promising miRs associated with PE pathogenesis and identify areas of methodology which could account for often conflicting results. Results Some of the most frequently differentially expressed miRs in PE include miR-210, miR-223 and miR-126/126* which associate strongly with the etiological domains of hypoxia, immunology and angiogenesis. Members of the miR-515 family belonging to the imprinted chromosome 19 miR cluster with putative roles in trophoblast invasion were also found to be differentially expressed. Certain miRs appear to associate with more severe forms of PE such as miR-210 and the immune-related miR-181a and miR-15 families. Patterns of miR expression may help pinpoint key pathways (e.g. IL-6/miR-223/STAT3) and aid in untangling the heterogeneous nature of PE. The detectable presence of many PE-associated miRs in antenatal circulatory samples suggests their usefulness as predictive biomarkers. Further progress in ascertaining the clinical value of miRs and in understanding how they might contribute to pathogenesis is predicated upon resolving current methodological challenges in studies. These include differences in diagnostic criteria, cohort characteristics, sampling technique, RNA isolation and platform-dependent variation in miR profiling. Conclusion Reviewing studies of PE-associated miRs has revealed their potential as informants of underlying target genes and pathways relating to PE pathogenesis. However, the incongruity in results across current studies hampers their

  10. Developing Meaning for Algebraic Procedures: An Exploration of the Connections Undergraduate Students Make between Algebraic Rational Expressions and Basic Number Properties

    ERIC Educational Resources Information Center

    Yantz, Jennifer

    2013-01-01

    The attainment and retention of later algebra skills in high school has been identified as a factor significantly impacting the postsecondary success of students majoring in STEM fields. Researchers maintain that learners develop meaning for algebraic procedures by forming connections to the basic number system properties. The present study…

  11. Magellan: a web based system for the integrated analysis of heterogeneous biological data and annotations; application to DNA copy number and expression data in ovarian cancer.

    PubMed

    Kingsley, Chris B; Kuo, Wen-Lin; Polikoff, Daniel; Berchuck, Andy; Gray, Joe W; Jain, Ajay N

    2007-02-05

    Recent advances in high throughput biological methods allow researchers to generate enormous amounts of data from a single experiment. In order to extract meaningful conclusions from this tidal wave of data, it will be necessary to develop analytical methods of sufficient power and utility. It is particularly important that biologists themselves be able to perform many of these analyses, such that their background knowledge of the experimental system under study can be used to interpret results and direct further inquiries. We have developed a web-based system, Magellan, which allows the upload, storage, and analysis of multivariate data and textual or numerical annotations. Data and annotations are treated as abstract entities, to maximize the different types of information the system can store and analyze. Annotations can be used in analyses/visualizations, as a means of subsetting data to reduce dimensionality, or as a means of projecting variables from one data type or data set to another. Analytical methods are deployed within Magellan such that new functionalities can be added in a straightforward fashion. Using Magellan, we performed an integrated analysis of genome-wide comparative genomic hybridization (CGH), mRNA expression, and clinical data from ovarian tumors. Analyses included the use of permutation-based methods to identify genes whose mRNA expression levels correlated with patient survival, a nearest neighbor classifier to predict patient survival from CGH data, and curated annotations such as genomic position and derived annotations such as statistical computations to explore the quantitative relationship between CGH and mRNA expression data.

  12. Application of dimensionless sediment rating curves to predict suspended-sediment concentrations, bedload, and annual sediment loads for rivers in Minnesota

    USGS Publications Warehouse

    Ellison, Christopher A.; Groten, Joel T.; Lorenz, David L.; Koller, Karl S.

    2016-10-27

    Consistent and reliable sediment data are needed by Federal, State, and local government agencies responsible for monitoring water quality, planning river restoration, quantifying sediment budgets, and evaluating the effectiveness of sediment reduction strategies. Heightened concerns about excessive sediment in rivers and the challenge to reduce costs and eliminate data gaps has guided Federal and State interests in pursuing alternative methods for measuring suspended and bedload sediment. Simple and dependable data collection and estimation techniques are needed to generate hydraulic and water-quality information for areas where data are unavailable or difficult to collect.The U.S. Geological Survey, in cooperation with the Minnesota Pollution Control Agency and the Minnesota Department of Natural Resources, completed a study to evaluate the use of dimensionless sediment rating curves (DSRCs) to accurately predict suspended-sediment concentrations (SSCs), bedload, and annual sediment loads for selected rivers and streams in Minnesota based on data collected during 2007 through 2013. This study included the application of DSRC models developed for a small group of streams located in the San Juan River Basin near Pagosa Springs in southwestern Colorado to rivers in Minnesota. Regionally based DSRC models for Minnesota also were developed and compared to DSRC models from Pagosa Springs, Colorado, to evaluate which model provided more accurate predictions of SSCs and bedload in Minnesota.Multiple measures of goodness-of-fit were developed to assess the effectiveness of DSRC models in predicting SSC and bedload for rivers in Minnesota. More than 600 dimensionless ratio values of SSC, bedload, and streamflow were evaluated and delineated according to Pfankuch stream stability categories of “good/fair” and “poor” to develop four Minnesota-based DSRC models. The basis for Pagosa Springs and Minnesota DSRC model effectiveness was founded on measures of goodness

  13. Expression of ipt gene controlled by an ethylene and auxin responsive fragment of the LEACO1 promoter increases flower number in transgenic Nicotiana tabacum.

    PubMed

    Khodakovskaya, Mariya; Zhao, Degang; Smith, William; Li, Yi; McAvoy, Richard

    2006-11-01

    Cytokinins play important roles in regulating plant growth and development. A new genetic construct for regulating cytokinin content in plant cells was cloned and tested. The gene coding for isopentenyl transferase (ipt) was placed under the control of a 0.821 kb fragment of the 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase gene promoter from Lycopersicon esculentum (LEACO1) and introduced into Nicotiana tabacum (cv. Havana). Some LEACO1(0.821) (kb)-ipt transgenic plant lines displayed normal shoot morphology but with a dramatic increase in the number of flower buds compared to nontransgenic plants. Other transgenic lines produced excessive lateral branch development but no change in flower bud number. Isolated leaves of transgenic tobacco plants showed a significantly prolonged retention of chlorophyll under dark incubation (25 degrees C for 20 days). Leaves of nontransformed plants senesced gradually under the same conditions. Experiments with LEACO1(0.821) (kb)-gus transgenic tobacco plants suggested auxin and ethylene involvement in induction of LEACO1(0.821) (kb) promoter activity. Multiple copies of nucleotide base sequences associated with either ethylene or auxin response elements were identified in the LEACO1(0.821) (kb) promoter fragment. The LEACO1(0.821) (kb)-ipt fusion gene appears to have potential utility for improving certain ornamental and agricultural crop species by increasing flower bud initiation and altering branching habit. PMID:16786314

  14. Evolutionary changes in gene expression, coding sequence and copy-number at the Cyp6g1 locus contribute to resistance to multiple insecticides in Drosophila.

    PubMed

    Harrop, Thomas W R; Sztal, Tamar; Lumb, Christopher; Good, Robert T; Daborn, Phillip J; Batterham, Philip; Chung, Henry

    2014-01-01

    Widespread use of insecticides has led to insecticide resistance in many populations of insects. In some populations, resistance has evolved to multiple pesticides. In Drosophila melanogaster, resistance to multiple classes of insecticide is due to the overexpression of a single cytochrome P450 gene, Cyp6g1. Overexpression of Cyp6g1 appears to have evolved in parallel in Drosophila simulans, a sibling species of D. melanogaster, where it is also associated with insecticide resistance. However, it is not known whether the ability of the CYP6G1 enzyme to provide resistance to multiple insecticides evolved recently in D. melanogaster or if this function is present in all Drosophila species. Here we show that duplication of the Cyp6g1 gene occurred at least four times during the evolution of different Drosophila species, and the ability of CYP6G1 to confer resistance to multiple insecticides exists in D. melanogaster and D. simulans but not in Drosophila willistoni or Drosophila virilis. In D. virilis, which has multiple copies of Cyp6g1, one copy confers resistance to DDT and another to nitenpyram, suggesting that the divergence of protein sequence between copies subsequent to the duplication affected the activity of the enzyme. All orthologs tested conferred resistance to one or more insecticides, suggesting that CYP6G1 had the capacity to provide resistance to anthropogenic chemicals before they existed. Finally, we show that expression of Cyp6g1 in the Malpighian tubules, which contributes to DDT resistance in D. melanogaster, is specific to the D. melanogaster-D. simulans lineage. Our results suggest that a combination of gene duplication, regulatory changes and protein coding changes has taken place at the Cyp6g1 locus during evolution and this locus may play a role in providing resistance to different environmental toxins in different Drosophila species.

  15. Early Ovariectomy Results in Reduced Numbers of CD11c+/CD11b+ Spleen Cells and Impacts Disease Expression in Murine Lupus

    PubMed Central

    Cunningham, Melissa A.; Wirth, Jena R.; Scott, Jennifer L.; Eudaly, Jackie; Collins, Erin L.; Gilkeson, Gary S.

    2016-01-01

    Ninety percent of those diagnosed with systemic lupus erythematosus are female, with peak incidence between the ages of 15 and 45, when women are most hormonally active. Despite significant research effort, the mechanisms underlying this sex bias remain unclear. We previously showed that a functional knockout of estrogen receptor alpha (ERα) resulted in significantly reduced renal disease and increased survival in murine lupus. Dendritic cell (DC) development, which requires both estrogen and ERα, is impacted, as is activation status and cytokine production. Since both estrogen and testosterone levels have immunomodulating effects, we presently studied the phenotype of NZM2410 lupus-prone mice following post- and prepubertal ovariectomy (OVX) ± estradiol (E2) replacement to determine the impact of hormonal status on disease expression and DC development in these mice. We observed a trend toward survival benefit in addition to decreased proteinuria and improved renal histology in the early OVX, but not late OVX- or E2-repleted WT mice. Interestingly, there was also a significant difference in splenic DC subsets by flow cytometry. Spleens from NZM mice OVX’d early had a significant decrease in proinflammatory CD11c+CD11b+ DCs (vs. unmanipulated WTs, late OVX- and E2-repleted mice). These early OVX’d animals also had a significant increase in tolerogenic CD11c+CD8a+ DCs vs. WT. These data join a growing body of evidence that supports a role for hormone modulation of DCs that likely impacts the penetrance and severity of autoimmune diseases, such as lupus. PMID:26913030

  16. Evolutionary Changes in Gene Expression, Coding Sequence and Copy-Number at the Cyp6g1 Locus Contribute to Resistance to Multiple Insecticides in Drosophila

    PubMed Central

    Harrop, Thomas W. R.; Sztal, Tamar; Lumb, Christopher; Good, Robert T.; Daborn, Phillip J.; Batterham, Philip; Chung, Henry

    2014-01-01

    Widespread use of insecticides has led to insecticide resistance in many populations of insects. In some populations, resistance has evolved to multiple pesticides. In Drosophila melanogaster, resistance to multiple classes of insecticide is due to the overexpression of a single cytochrome P450 gene, Cyp6g1. Overexpression of Cyp6g1 appears to have evolved in parallel in Drosophila simulans, a sibling species of D. melanogaster, where it is also associated with insecticide resistance. However, it is not known whether the ability of the CYP6G1 enzyme to provide resistance to multiple insecticides evolved recently in D. melanogaster or if this function is present in all Drosophila species. Here we show that duplication of the Cyp6g1 gene occurred at least four times during the evolution of different Drosophila species, and the ability of CYP6G1 to confer resistance to multiple insecticides exists in D. melanogaster and D. simulans but not in Drosophila willistoni or Drosophila virilis. In D. virilis, which has multiple copies of Cyp6g1, one copy confers resistance to DDT and another to nitenpyram, suggesting that the divergence of protein sequence between copies subsequent to the duplication affected the activity of the enzyme. All orthologs tested conferred resistance to one or more insecticides, suggesting that CYP6G1 had the capacity to provide resistance to anthropogenic chemicals before they existed. Finally, we show that expression of Cyp6g1 in the Malpighian tubules, which contributes to DDT resistance in D. melanogaster, is specific to the D. melanogaster–D. simulans lineage. Our results suggest that a combination of gene duplication, regulatory changes and protein coding changes has taken place at the Cyp6g1 locus during evolution and this locus may play a role in providing resistance to different environmental toxins in different Drosophila species. PMID:24416303

  17. Systematic multiplex polymerase chain reaction and reverse transcription-polymerase chain reaction analyses of changes in copy number and expression of proto-oncogenes and tumor suppressor genes in cancer tissues and cell lines.

    PubMed

    Yamamoto, Miyako; Metoki, Rikiya; Yamamoto, Fumiichiro

    2004-10-01

    Systematic multiplex reverse transcription-polymerase chain reaction (SM RT-PCR) is distinguishable from other multiplex RT-PCR methods by (i) utilization of primers that amplify sequences that fall within a single exon of the genes, (ii) utilization of genomic DNA as a calibration standard, and (iii) optimized PCR conditions that allow amplification of bands of similar intensity using genomic DNA template. We previously developed the human experimental systems of 68 glycosyltransferase genes, 39 Hox genes, and 26 integrin subunit genes, and analyzed the expression of those genes in human adult tissues. Here we report the establishment of an SM RT-PCR system of proto-oncogenes and tumor suppressor genes and the analysis of gene expression in human cancer tissues and cell lines. We also demonstrate that the SM RT-PCR system, which was developed for cDNA expression analysis, could also be used successfully for more exquisite analysis of copy number changes in genomic DNA. We observed a decrease in band intensity of HRAS, TP73, CDKN2A, and CDKN2B genes in most of the breast and prostate cancer cell lines examined. The decrease in copy number of HRAS proto-oncogene leads us to suspect the presence of tumor suppressor genes in the vicinity of this gene on chromosome 11p15.5.

  18. Scanning copy number and gene expression on the 16p13.3-13.2 chromosomal region by the systematic multiplex polymerase chain reaction and reverse transcription-polymerase chain reaction methods.

    PubMed

    Yamamoto, Miyako; Ahn, Ray Hyungjoo; Yamamoto, Fumiichiro

    2006-07-01

    We developed the systematic multiplex reverse transcription-PCR (SM RT-PCR) method that is distinguishable from other multiplex RT-PCR methods by optimized PCR conditions allowing amplification of sequences that fall within a single exon of genes of similar band intensity using genomic DNA template as a calibration standard. Using an SM RT-PCR system of proto-oncogenes and tumor suppressor genes, we previously showed that the SM RT-PCR system, which was developed for cDNA expression analysis, could also be used for a more exquisite analysis of copy number changes in genomic DNA. Here we report that the SM PCR method semiquantitatively detected less than a two-fold difference in copy number. Furthermore, we also report the results of subchromosomal scanning of copy number and expression using the SM PCR and SM RT-PCR methods. We identified and characterized the novel homozygous deletion that spans over 12-plus genes on 16p13.3-13.2 in the MDA-MB-468 breast cancer cell line.

  19. Study of Nonlinear MHD Tribological Squeeze Film at Generalized Magnetic Reynolds Numbers Using DTM

    PubMed Central

    Rashidi, Mohammad Mehdi; Freidoonimehr, Navid; Momoniat, Ebrahim; Rostami, Behnam

    2015-01-01

    In the current article, a combination of the differential transform method (DTM) and Padé approximation method are implemented to solve a system of nonlinear differential equations modelling the flow of a Newtonian magnetic lubricant squeeze film with magnetic induction effects incorporated. Solutions for the transformed radial and tangential momentum as well as solutions for the radial and tangential induced magnetic field conservation equations are determined. The DTM-Padé combined method is observed to demonstrate excellent convergence, stability and versatility in simulating the magnetic squeeze film problem. The effects of involved parameters, i.e. squeeze Reynolds number (N1), dimensionless axial magnetic force strength parameter (N2), dimensionless tangential magnetic force strength parameter (N3), and magnetic Reynolds number (Rem) are illustrated graphically and discussed in detail. Applications of the study include automotive magneto-rheological shock absorbers, novel aircraft landing gear systems and biological prosthetics. PMID:26267247

  20. Study of Nonlinear MHD Tribological Squeeze Film at Generalized Magnetic Reynolds Numbers Using DTM.

    PubMed

    Rashidi, Mohammad Mehdi; Freidoonimehr, Navid; Momoniat, Ebrahim; Rostami, Behnam

    2015-01-01

    In the current article, a combination of the differential transform method (DTM) and Padé approximation method are implemented to solve a system of nonlinear differential equations modelling the flow of a Newtonian magnetic lubricant squeeze film with magnetic induction effects incorporated. Solutions for the transformed radial and tangential momentum as well as solutions for the radial and tangential induced magnetic field conservation equations are determined. The DTM-Padé combined method is observed to demonstrate excellent convergence, stability and versatility in simulating the magnetic squeeze film problem. The effects of involved parameters, i.e. squeeze Reynolds number (N1), dimensionless axial magnetic force strength parameter (N2), dimensionless tangential magnetic force strength parameter (N3), and magnetic Reynolds number (Rem) are illustrated graphically and discussed in detail. Applications of the study include automotive magneto-rheological shock absorbers, novel aircraft landing gear systems and biological prosthetics. PMID:26267247

  1. Widespread changes in neurotransmitter expression and number of enteric neurons and interstitial cells of Cajal in lethal spotted mice: an explanation for persisting dysmotility after operation for Hirschsprung's disease?

    PubMed

    Sandgren, Katarina; Larsson, Lars T; Ekblad, Eva

    2002-05-01

    Gastrointestinal motor dysfunction persists in a large number of children subjected to surgical treatment for Hirschsprung's disease, indicating abnormalities in the remaining intestine. The aim of the study was to detect possible alterations in frequency and topographic distribution of enteric neurons and interstitial cells of Cajal in an experimental model (the lethal spotted mouse displaying a short rectal aganglionosis) for Hirschsprung's disease. Specimens from the intestinal tract from homozygous (aganglionic) and heterozygous (healthy littermates) were examined using histochemistry, in situ hybridization, and immunohistochemistry. In ileum and colon, ie, regions proximal to the aganglionosis, changes in the expression of neuropeptides and neuronal nitric oxide synthase and in the number of enteric neurons and interstitial cells of Cajal could be detected in homozygous versus heterozygous mice. The described changes are suggested to contribute to the dysmotility remaining after surgical resection of the aganglionic segment in Hirschsprung's disease.

  2. Association and prognostic significance of BRCA1/2-mutation status with neoantigen load, number of tumor-infiltrating lymphocytes and expression of PD-1/PD-L1 in high grade serous ovarian cancer

    PubMed Central

    Strickland, Kyle C.; Howitt, Brooke E.; Shukla, Sachet A.; Rodig, Scott; Ritterhouse, Lauren L.; Liu, Joyce F.; Garber, Judy E.; Chowdhury, Dipanjan; Wu, Catherine J.; D'Andrea, Alan D.; Matulonis, Ursula A.; Konstantinopoulos, Panagiotis A.

    2016-01-01

    Immune checkpoint inhibitors (e.g., anti-PD-1 and anti-PD-L1 antibodies) have demonstrated remarkable efficacy against hypermutated cancers such as melanomas and lung carcinomas. One explanation for this effect is that hypermutated lesions harbor more tumor-specific neoantigens that stimulate recruitment of an increased number of tumor-infiltrating lymphocytes (TILs), which is counterbalanced by overexpression of immune checkpoints such as PD-1 or PD-L1. Given that BRCA1/2-mutated high grade serous ovarian cancers (HGSOCs) exhibit a higher mutational load and a unique mutational signature with an elevated number of larger indels up to 50 bp, we hypothesized that they may also harbor more tumor-specific neoantigens, and, therefore, exhibit increased TILs and PD-1/PD-L1 expression. Here, we report significantly higher predicted neoantigens in BRCA1/2-mutated tumors compared to tumors without alterations in homologous recombination (HR) genes (HR-proficient tumors). Tumors with higher neoantigen load were associated with improved overall survival and higher expression of immune genes associated with tumor cytotoxicity such as genes of the TCR, the IFN-gamma and the TNFR pathways. Furthermore, immunohistochemistry studies demonstrated that BRCA1/2-mutated tumors exhibited significantly increased CD3+ and CD8+ TILs, as well as elevated expression of PD-1 and PD-L1 in tumor-associated immune cells compared to HR-proficient tumors. Survival analysis showed that both BRCA1/2-mutation status and number of TILs were independently associated with outcome. Of note, two distinct groups of HGSOCs, one with very poor prognosis (HR proficient with low number of TILs) and one with very good prognosis (BRCA1/2-mutated tumors with high number of TILs) were defined. These findings support a link between BRCA1/2-mutation status, immunogenicity and survival, and suggesting that BRCA1/2-mutated HGSOCs may be more sensitive to PD-1/PD-L1 inhibitors compared to HR-proficient HGSOCs. PMID

  3. Association and prognostic significance of BRCA1/2-mutation status with neoantigen load, number of tumor-infiltrating lymphocytes and expression of PD-1/PD-L1 in high grade serous ovarian cancer.

    PubMed

    Strickland, Kyle C; Howitt, Brooke E; Shukla, Sachet A; Rodig, Scott; Ritterhouse, Lauren L; Liu, Joyce F; Garber, Judy E; Chowdhury, Dipanjan; Wu, Catherine J; D'Andrea, Alan D; Matulonis, Ursula A; Konstantinopoulos, Panagiotis A

    2016-03-22

    Immune checkpoint inhibitors (e.g., anti-PD-1 and anti-PD-L1 antibodies) have demonstrated remarkable efficacy against hypermutated cancers such as melanomas and lung carcinomas. One explanation for this effect is that hypermutated lesions harbor more tumor-specific neoantigens that stimulate recruitment of an increased number of tumor-infiltrating lymphocytes (TILs), which is counterbalanced by overexpression of immune checkpoints such as PD-1 or PD-L1. Given that BRCA1/2-mutated high grade serous ovarian cancers (HGSOCs) exhibit a higher mutational load and a unique mutational signature with an elevated number of larger indels up to 50 bp, we hypothesized that they may also harbor more tumor-specific neoantigens, and, therefore, exhibit increased TILs and PD-1/PD-L1 expression. Here, we report significantly higher predicted neoantigens in BRCA1/2-mutated tumors compared to tumors without alterations in homologous recombination (HR) genes (HR-proficient tumors). Tumors with higher neoantigen load were associated with improved overall survival and higher expression of immune genes associated with tumor cytotoxicity such as genes of the TCR, the IFN-gamma and the TNFR pathways. Furthermore, immunohistochemistry studies demonstrated that BRCA1/2-mutated tumors exhibited significantly increased CD3+ and CD8+ TILs, as well as elevated expression of PD-1 and PD-L1 in tumor-associated immune cells compared to HR-proficient tumors. Survival analysis showed that both BRCA1/2-mutation status and number of TILs were independently associated with outcome. Of note, two distinct groups of HGSOCs, one with very poor prognosis (HR proficient with low number of TILs) and one with very good prognosis (BRCA1/2-mutated tumors with high number of TILs) were defined. These findings support a link between BRCA1/2-mutation status, immunogenicity and survival, and suggesting that BRCA1/2-mutated HGSOCs may be more sensitive to PD-1/PD-L1 inhibitors compared to HR-proficient HGSOCs.

  4. Rayleigh- and Prandtl-number dependence of the large-scale flow-structure in weakly-rotating turbulent thermal convection

    NASA Astrophysics Data System (ADS)

    Weiss, Stephan; Wei, Ping; Ahlers, Guenter

    2015-11-01

    Turbulent thermal convection under rotation shows a remarkable variety of different flow states. The Nusselt number (Nu) at slow rotation rates (expressed as the dimensionless inverse Rossby number 1/Ro), for example, is not a monotonic function of 1/Ro. Different 1/Ro-ranges can be observed with different slopes ∂Nu / ∂ (1 / Ro) . Some of these ranges are connected by sharp transitions where ∂Nu / ∂ (1 / Ro) changes discontinuously. We investigate different regimes in cylindrical samples of aspect ratio Γ = 1 by measuring temperatures at the sidewall of the sample for various Prandtl numbers in the range 3 < Pr < 35 and Rayleigh numbers in the range of 108 < Ra < 4 ×1011 . From these measurements we deduce changes of the flow structure. We learn about the stability and dynamics of the large-scale circulation (LSC), as well as about its breakdown and the onset of vortex formation close to the top and bottom plate. We shall examine correlations between these measurements and changes in the heat transport. This work was supported by NSF grant DRM11-58514. SW acknowledges support by the Deutsche Forschungsgemeinschaft.

  5. Phenotypic variation caused by variation in the relative copy number of pDU1-based plasmids expressing the GAF domain of Pkn41 or Pkn42 in Anabaena sp. PCC 7120.

    PubMed

    Yang, Yang; Huang, Xiao-Zhen; Wang, Li; Risoul, Veronique; Zhang, Cheng-Cai; Chen, Wen-Li

    2013-01-01

    The cyanobacterium Anabaena (Nostoc) sp. PCC 7120 is a model for cyanobacterial cell differentiation studies. pDU1, an endogenous plasmid in Nostoc sp. PCC 7524, is used as the only cyanobacterial replicon for Anabaena (Nostoc) studies. However, the relative copy numbers of pDU1-based plasmids in Anabaena (Nostoc) sp. PCC 7120 are not well studied. We found that the relative plasmid copy number of one such vector, pRL25T, varied widely, especially when the vector carried a recombinant insert, under different conditions, ranging from 0.53 to 1812 per chromosome in different recombinant strains tested, either in independent clones of the same strain or in the same clone under different growth conditions. The phenotypes caused by pRL25T-driven expression of green fluorescent protein or the GAF domain of Pkn41 or Pkn42 varied depending on the independent clones analyzed. This phenotypic variation correlated with the relative plasmid copy number present in cells.

  6. A dimensionless ordered pull-through model of the mammalian lens epithelium evidences scaling across species and explains the age-dependent changes in cell density in the human lens

    PubMed Central

    Wu, Jun Jie; Wu, Weiju; Tholozan, Frederique M.; Saunter, Christopher D.; Girkin, John M.; Quinlan, Roy A.

    2015-01-01

    We present a mathematical (ordered pull-through; OPT) model of the cell-density profile for the mammalian lens epithelium together with new experimental data. The model is based upon dimensionless parameters, an important criterion for inter-species comparisons where lens sizes can vary greatly (e.g. bovine (approx. 18 mm); mouse (approx. 2 mm)) and confirms that mammalian lenses scale with size. The validated model includes two parameters: β/α, which is the ratio of the proliferation rate in the peripheral and in the central region of the lens; and γGZ, a dimensionless pull-through parameter that accounts for the cell transition and exit from the epithelium into the lens body. Best-fit values were determined for mouse, rat, rabbit, bovine and human lens epithelia. The OPT model accounts for the peak in cell density at the periphery of the lens epithelium, a region where cell proliferation is concentrated and reaches a maximum coincident with the germinative zone. The β/α ratio correlates with the measured FGF-2 gradient, a morphogen critical to lens cell survival, proliferation and differentiation. As proliferation declines with age, the OPT model predicted age-dependent changes in cell-density profiles, which we observed in mouse and human lenses. PMID:26236824

  7. Drag and Strouhal number measurements for porous circular cylinders

    NASA Astrophysics Data System (ADS)

    Kanale, Anup; Sellappan, Prabu; Luhar, Mitul

    2015-11-01

    Flow past solid bluff bodies has been studied extensively, and both experimental and computational results are well documented. However, there is limited data available for flows past porous bluff bodies, in spite of their abundance in nature. As an effort in this direction, we study the wake behind porous circular cylinders via water channel experiments employing particle image velocimetry (PIV). The experiments systematically test the effect of three dimensionless parameters: ReP , the Reynolds number based on pore size, ReD , the Reynolds number based on cylinder diamter, and ϕ the porosity of the sleeve. Specifically the PIV data are used to estimate the drag coefficient and Strouhal number for 600 <= ReD <= 5000 , 18 <= ReP <= 600 and 0 . 33 <= ϕ <= 0 . 75 . The results obtained are compared with solid cylinders to identify the effect of cylinder permeability on flow characteristics.

  8. Mice selectively bred for High and Low fear behavior show differences in the number of pMAPK (p44/42 ERK) expressing neurons in lateral amygdala following Pavlovian fear conditioning.

    PubMed

    Coyner, Jennifer; McGuire, Jennifer L; Parker, Clarissa C; Ursano, Robert J; Palmer, Abraham A; Johnson, Luke R

    2014-07-01

    Individual variability in the acquisition, consolidation and extinction of conditioned fear potentially contributes to the development of fear pathology including posttraumatic stress disorder (PTSD). Pavlovian fear conditioning is a key tool for the study of fundamental aspects of fear learning. Here, we used a selected mouse line of High and Low Pavlovian conditioned fear created from an advanced intercrossed line (AIL) in order to begin to identify the cellular basis of phenotypic divergence in Pavlovian fear conditioning. We investigated whether phosphorylated MAPK (p44/42 ERK/MAPK), a protein kinase required in the amygdala for the acquisition and consolidation of Pavlovian fear memory, is differentially expressed following Pavlovian fear learning in the High and Low fear lines. We found that following Pavlovian auditory fear conditioning, High and Low line mice differ in the number of pMAPK-expressing neurons in the dorsal sub nucleus of the lateral amygdala (LAd). In contrast, this difference was not detected in the ventral medial (LAvm) or ventral lateral (LAvl) amygdala sub nuclei or in control animals. We propose that this apparent increase in plasticity at a known locus of fear memory acquisition and consolidation relates to intrinsic differences between the two fear phenotypes. These data provide important insights into the micronetwork mechanisms encoding phenotypic differences in fear. Understanding the circuit level cellular and molecular mechanisms that underlie individual variability in fear learning is critical for the development of effective treatment of fear-related illnesses such as PTSD.

  9. The RNA-Binding Chaperone Hfq Is an Important Global Regulator of Gene Expression in Pasteurella multocida and Plays a Crucial Role in Production of a Number of Virulence Factors, Including Hyaluronic Acid Capsule

    PubMed Central

    Mégroz, Marianne; Kleifeld, Oded; Wright, Amy; Powell, David; Harrison, Paul; Adler, Ben; Harper, Marina

    2016-01-01

    The Gram-negative bacterium Pasteurella multocida is the causative agent of a number of economically important animal diseases, including avian fowl cholera. Numerous P. multocida virulence factors have been identified, including capsule, lipopolysaccharide (LPS), and filamentous hemagglutinin, but little is known about how the expression of these virulence factors is regulated. Hfq is an RNA-binding protein that facilitates riboregulation via interaction with small noncoding RNA (sRNA) molecules and their mRNA targets. Here, we show that a P. multocida hfq mutant produces significantly less hyaluronic acid capsule during all growth phases and displays reduced in vivo fitness. Transcriptional and proteomic analyses of the hfq mutant during mid-exponential-phase growth revealed altered transcript levels for 128 genes and altered protein levels for 78 proteins. Further proteomic analyses of the hfq mutant during the early exponential growth phase identified 106 proteins that were produced at altered levels. Both the transcript and protein levels for genes/proteins involved in capsule biosynthesis were reduced in the hfq mutant, as were the levels of the filamentous hemagglutinin protein PfhB2 and its secretion partner LspB2. In contrast, there were increased expression levels of three LPS biosynthesis genes, encoding proteins involved in phosphocholine and phosphoethanolamine addition to LPS, suggesting that these genes are negatively regulated by Hfq-dependent mechanisms. Taken together, these data provide the first evidence that Hfq plays a crucial role in regulating the global expression of P. multocida genes, including the regulation of key P. multocida virulence factors, capsule, LPS, and filamentous hemagglutinin. PMID:26883595

  10. The RNA-Binding Chaperone Hfq Is an Important Global Regulator of Gene Expression in Pasteurella multocida and Plays a Crucial Role in Production of a Number of Virulence Factors, Including Hyaluronic Acid Capsule.

    PubMed

    Mégroz, Marianne; Kleifeld, Oded; Wright, Amy; Powell, David; Harrison, Paul; Adler, Ben; Harper, Marina; Boyce, John D

    2016-05-01

    The Gram-negative bacterium Pasteurella multocida is the causative agent of a number of economically important animal diseases, including avian fowl cholera. Numerous P. multocida virulence factors have been identified, including capsule, lipopolysaccharide (LPS), and filamentous hemagglutinin, but little is known about how the expression of these virulence factors is regulated. Hfq is an RNA-binding protein that facilitates riboregulation via interaction with small noncoding RNA (sRNA) molecules and their mRNA targets. Here, we show that a P. multocida hfq mutant produces significantly less hyaluronic acid capsule during all growth phases and displays reduced in vivo fitness. Transcriptional and proteomic analyses of the hfq mutant during mid-exponential-phase growth revealed altered transcript levels for 128 genes and altered protein levels for 78 proteins. Further proteomic analyses of the hfq mutant during the early exponential growth phase identified 106 proteins that were produced at altered levels. Both the transcript and protein levels for genes/proteins involved in capsule biosynthesis were reduced in the hfq mutant, as were the levels of the filamentous hemagglutinin protein PfhB2 and its secretion partner LspB2. In contrast, there were increased expression levels of three LPS biosynthesis genes, encoding proteins involved in phosphocholine and phosphoethanolamine addition to LPS, suggesting that these genes are negatively regulated by Hfq-dependent mechanisms. Taken together, these data provide the first evidence that Hfq plays a crucial role in regulating the global expression of P. multocida genes, including the regulation of key P. multocida virulence factors, capsule, LPS, and filamentous hemagglutinin. PMID:26883595

  11. The RNA-Binding Chaperone Hfq Is an Important Global Regulator of Gene Expression in Pasteurella multocida and Plays a Crucial Role in Production of a Number of Virulence Factors, Including Hyaluronic Acid Capsule.

    PubMed

    Mégroz, Marianne; Kleifeld, Oded; Wright, Amy; Powell, David; Harrison, Paul; Adler, Ben; Harper, Marina; Boyce, John D

    2016-05-01

    The Gram-negative bacterium Pasteurella multocida is the causative agent of a number of economically important animal diseases, including avian fowl cholera. Numerous P. multocida virulence factors have been identified, including capsule, lipopolysaccharide (LPS), and filamentous hemagglutinin, but little is known about how the expression of these virulence factors is regulated. Hfq is an RNA-binding protein that facilitates riboregulation via interaction with small noncoding RNA (sRNA) molecules and their mRNA targets. Here, we show that a P. multocida hfq mutant produces significantly less hyaluronic acid capsule during all growth phases and displays reduced in vivo fitness. Transcriptional and proteomic analyses of the hfq mutant during mid-exponential-phase growth revealed altered transcript levels for 128 genes and altered protein levels for 78 proteins. Further proteomic analyses of the hfq mutant during the early exponential growth phase identified 106 proteins that were produced at altered levels. Both the transcript and protein levels for genes/proteins involved in capsule biosynthesis were reduced in the hfq mutant, as were the levels of the filamentous hemagglutinin protein PfhB2 and its secretion partner LspB2. In contrast, there were increased expression levels of three LPS biosynthesis genes, encoding proteins involved in phosphocholine and phosphoethanolamine addition to LPS, suggesting that these genes are negatively regulated by Hfq-dependent mechanisms. Taken together, these data provide the first evidence that Hfq plays a crucial role in regulating the global expression of P. multocida genes, including the regulation of key P. multocida virulence factors, capsule, LPS, and filamentous hemagglutinin.

  12. Neonatal alcohol exposure and the hippocampus in developing male rats: effects on behaviorally induced CA1 c-Fos expression, CA1 pyramidal cell number, and contextual fear conditioning

    PubMed Central

    Murawski, Nathen J.; Klintsova, Anna Y.; Stanton, Mark E.

    2012-01-01

    Rats exposed to a high binge-like dose of alcohol over postnatal days (PD) 4-9 show reductions in CA1 pyramidal cells and impairments on behavioral tasks that depend on the hippocampus. We first examined hippocampal c-Fos expression as a marker of neuronal activity in normally developing rats following different phases of the context preexposure facilitation effect (CPFE) paradigm (Exp. 1). During the CPFE, preexposure to the training context facilitates contextual conditioning to an immediate shock given on a subsequent occasion. We then examined the relationship between CPFE impairment, hippocampal cell loss and c-Fos expression in rats exposed to alcohol over PD 4-9 (Exp. 2). Normally developing (Exp. 1), sham-intubated control (SI), and PD 4-9 alcohol-exposed (4.00g and 5.25g/kg/day; Exp. 2) juvenile male rats were trained on the CPFE. The CPFE occurs over three phases separated by 24h. Starting on PD 31, rats were preexposed to Context A or Context B for five minutes. 24h later, all rats received an immediate, 1.5 mA foot shock in Context A. Finally, rats were tested for contextual conditioning in Context A on PD 33. Normally developing and SI rats preexposed to Context A showed enhanced contextual fear compared to those preexposed to Context B (Exp. 1) or alcohol-exposed rats preexposed to Context A (Exp. 2). Rats were sacrificed 2h following different phases of the CPFE and processed for c-Fos immunohistochemistry (Exp. 1 and 2) and CA1 pyramidal cell quantification (Exp. 2). In Exp. 1, c-Fos+ cells in the DG were consistently high among rats preexposed to Context A (Pre), Context B (No Pre), or sacrificed directly from their home cage (Home) and did not differ across CPFE phases. CA3 and CA1 c-Fos+ cells were highest during preexposure and decreased across training phases, with Group No Pre showing greater numbers of c-Fos+ cells during training than Group Pre and Controls. In Exp. 2, SI rats had greater numbers of CA1 c-Fos+ cells compared alcohol

  13. Number Concepts with "Number Worlds": Thickening Understandings

    ERIC Educational Resources Information Center

    Liljedahl, Peter; Sinclair, Nathalie; Zazkis, Rina

    2006-01-01

    This study focuses on the nature of preservice elementary school teachers' understandings of several concepts in elementary number theory that are evoked by a computer-based microworld called "Number Worlds". In particular, the focus is on the concepts of factor, multiple and prime number. The notion of "thickness" is examined with respect to…

  14. All Square Chiliagonal Numbers

    ERIC Educational Resources Information Center

    A?iru, Muniru A.

    2016-01-01

    A square chiliagonal number is a number which is simultaneously a chiliagonal number and a perfect square (just as the well-known square triangular number is both triangular and square). In this work, we determine which of the chiliagonal numbers are perfect squares and provide the indices of the corresponding chiliagonal numbers and square…

  15. Hall Effect Thruster Interactions Data from the Russian Express-A2 and Express-A3 Satellites. Part 8; Acquire TM-Data for Type A and Type B Sensors for "Express A" Number 3 Satellite for the Period of January 1, 2001 to and Including March 31, 2001, Task 27C

    NASA Technical Reports Server (NTRS)

    Dunning, John (Technical Monitor); Sitnikova, N.; Volkov, D.; Maximov, I.; Petrusevich, V.; Allen, D.

    2003-01-01

    This 12-part report documents the data obtained from various sensor measurements taken aboard the Russian Express-A2 and Express-A3 spacecraft in Geosynchronous Earth Orbit (GEO). These GEO communications satellites, which were designed and built by NPO Prikladnoy Mekhaniki (NPO PM) of Zheleznogorsk, Russia, utilize Hall thruster propulsion systems for north-south and east-west stationkeeping and as of June 2002, were still operating at 80deg E. and 11deg W., respectively. Express-A2 was launched on March 12, 2000, while Express-A3 was launched on June 24, 2000. The diagnostic equipment from which these data were taken includes electric field strength sensors, ion current and energy sensors, and pressure sensors. The diagnostics and the Hall thruster propulsion systems are described in detail along with lists of tabular data from those diagnostics and propulsion system and other satellite systems. Space Power, Inc., now part of Pratt & Whitney's Chemical Systems Division, under contract NAS3 99151 to the NASA Glenn Research Center, obtained these data over several periods from March 12, 2000, through September 30, 2001. Each of the 12 individual reports describe, in detail, the propulsion systems as well as the diagnostic sensors utilized. Finally, parts 11 and 12 include the requirements to which NPO PM prepared and delivered these data.

  16. Hall Effect Thruster Interactions Data From the Russian Express-A2 and Express-A3 Satellites. Part 10; Acquire TM-Data for Type A and Type B Sensors for "Express-A" Number 3 Satellite for the Period of July 1, 2001 to and Including September 30, 2001, Task 27D

    NASA Technical Reports Server (NTRS)

    Dunning, John (Technical Monitor); Sitnikova, N.; Volkov, D.; Maximov, I.; Petrusevich, V.; Allen, D.

    2003-01-01

    This 12-part report documents the data obtained from various sensor measurements taken aboard the Russian Express-A2 and Express-A3 spacecraft in Geosynchronous Earth Orbit (GEO). These GEO communications satellites, which were designed and built by NPO Prikladnoy Mekhaniki (NPO PM) of Zheleznogorsk, Russia, utilize Hall thruster propulsion systems for north-south and east-west stationkeeping and as of June 2002, were still operating at 80 E. and 11 W., respectively. Express-A2 was launched on March 12, 2000, while Express-A3 was launched on June 24, 2000. The diagnostic equipment from which these data were taken includes electric field strength sensors, ion current and energy sensors, and pressure sensors. The diagnostics and the Hall thruster propulsion systems are described in detail along with lists of tabular data from those diagnostics and propulsion system and other satellite systems. Space Power, Inc., now part of Pratt & Whitney's Chemical Systems Division, under contract NAS3 99151 to the NASA Glenn Research Center, obtained these data over several periods from March 12, 2000, through September 30, 2001. Each of the 12 individual reports describe, in detail, the propulsion systems as well as the diagnostic sensors utilized. Finally, parts 11 and 12 include the requirements to which NPO PM prepared and delivered these data.

  17. Hall Effect Thruster Interactions Data From the Russian Express-A2 and Express-A3 Satellites. Part 2; Acquire TM Date for Type B Sensors for "Express-A" Number 2 Satellite for the Period of March 12, 2000 to and Including June 15, 2000, Task 25

    NASA Technical Reports Server (NTRS)

    Dunning, John (Technical Monitor); Sitnikova, N.; Volkov, D.; Maximov, I.; Petrusevich, V.; Allen, D.

    2003-01-01

    This 12-part report documents the data obtained from various sensor measurements taken aboard the Russian Express-A2 and Express-A3 spacecraft in Geosynchronous Earth Orbit (GEO). These GEO communications satellites, which were designed and built by NPO Prikladnoy Mekhaniki (NPO PM) of Zheleznogorsk, Russia, utilize Hall thruster propulsion systems for north-south and east-west stationkeeping and as of June 2002, were still operating at 80 E. and 11 W., respectively. Express-A2 was launched on March 12, 2000, while Express-A3 was launched on June 24, 2000. The diagnostic equipment from which these data were taken includes electric field strength sensors, ion current and energy sensors, and pressure sensors. The diagnostics and the Hall thruster propulsion systems are described in detail along with lists of tabular data from those diagnostics and propulsion system and other satellite systems. Space Power, Inc., now part of Pratt & Whitney's Chemical Systems Division, under contract NAS3 99151 to the NASA Glenn Research Center, obtained these data over several periods from March 12, 2000, through September 30, 2001. Each of the 12 individual reports describe, in detail, the propulsion systems as well as the diagnostic sensors utilized. Finally, parts 11 and 12 include the requirements to which NPO PM prepared and delivered these data.

  18. Hall Effect Thruster Interactions Data from the Russian Express-A2 and Express-A3 Satellites. Part 4; Acquire TM-Data for Type A and Type B Sensors for "Express-A" Number 3 Satellite, Task 27A

    NASA Technical Reports Server (NTRS)

    Sitnikova, N.; Volkov, D.; Maximov, I.; Petrusevich, V.; Allen, D.

    2003-01-01

    This 12-part report documents the data obtained from various sensor measurements taken aboard the Russian Express-A2 and Express-A3 spacecraft in Geosynchronous Earth Orbit (GEO). These GEO communications satellites, which were designed and built by NPO Prikladnoy Mekhaniki (NPO PM) of Zheleznogorsk, Russia, utilize Hall thruster propulsion systems for north-south and east-west stationkeeping and as of June 2002, were still operating at 80deg E., and 11deg W., respectively. Express-A2 was launched on March 12, 2000, while Express-A3 was launched on June 24, 2000. The diagnostic equipment from which these data were taken includes electric field strength sensors, ion current and energy sensors, and pressure sensors. The diagnostics and the Hall thruster propulsion systems are described in detail along with lists of tabular data from those diagnostics and propulsion system and other satellite systems. Space Power, Inc., now part of Pratt & Whitney's Chemical Systems Division, under contract NAS3-99151 to the NASA Glenn Research Center, obtained these data over several periods from March 12, 2000, through September 30, 2001. Each of the 12 individual reports describe, in detail, the propulsion systems as well as the diagnostic sensors utilized. Finally, parts 11 and 12 include the requirements to which NPO PM prepared and delivered these data.

  19. Expansion of real numbers by algebraic numbers

    NASA Astrophysics Data System (ADS)

    Hajime, Kaneko

    2008-01-01

    In this paper we represent the fractional part of ξαn, where ξ is a nonzero real number and α is an algebraic number. By using this representation, we give new lower bounds for the distance from ξαn to the nearest integer.

  20. Numbers Defy the Law of Large Numbers

    ERIC Educational Resources Information Center

    Falk, Ruma; Lann, Avital Lavie

    2015-01-01

    As the number of independent tosses of a fair coin grows, the rates of heads and tails tend to equality. This is misinterpreted by many students as being true also for the absolute numbers of the two outcomes, which, conversely, depart unboundedly from each other in the process. Eradicating that misconception, as by coin-tossing experiments,…

  1. Novel methods for evaluation of the Reynolds number of synthetic jets

    NASA Astrophysics Data System (ADS)

    Kordík, J.; Broučková, Z.; Vít, T.; Pavelka, M.; Trávníček, Z.

    2014-06-01

    The paper proposes four novel methods of evaluation of synthetic jet velocity amplitude (Reynolds number in dimensionless form). The methods are based on the measurement of synthetic jet actuator electrical input (alternating current and voltage) and are applicable for loudspeaker-based actuators with air as the working fluid. Experimental validations are performed by means of hot-wire anemometry and laser Doppler vibrometry. Uncertainty and limitation of the methods are discussed, including a proposal of an adequate incompressibility criterion. Ranges of applicability are specified. Additionally, the results are compared with available literature, namely with another method based on cavity pressure measurements, a good consistency is found.

  2. Anomalous baryon number nonconservation in pp collisions at 40 TeV

    NASA Astrophysics Data System (ADS)

    Aoyama, Hideaki; Goldberg, Haim

    1987-04-01

    We construct the coherent quantum state corresponding to a saddle-point solution of the standard electroweak theory (the “sphaleron”), as obtained by Klinkhamer and Manton. The matrix element connecting this state to a q overlineq state is then shown to depend crucially on a dimensionless strength gnAn of the sum of tree amplitudes for q overlineq→n W, n≃55. For A 55⩾ 70!., one may optimistically hope to see of the order of 10-100 baryon-number violatingevents a year at SSC at design luminosities.

  3. 32 CFR 1602.19 - Numbers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Numbers. 1602.19 Section 1602.19 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.19 Numbers. Cardinal numbers may be expressed by Arabic or Roman symbols....

  4. 32 CFR 1602.19 - Numbers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Numbers. 1602.19 Section 1602.19 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.19 Numbers. Cardinal numbers may be expressed by Arabic or Roman symbols....

  5. 32 CFR 1602.19 - Numbers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Numbers. 1602.19 Section 1602.19 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.19 Numbers. Cardinal numbers may be expressed by Arabic or Roman symbols....

  6. 32 CFR 1602.19 - Numbers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Numbers. 1602.19 Section 1602.19 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.19 Numbers. Cardinal numbers may be expressed by Arabic or Roman symbols....

  7. 32 CFR 1602.19 - Numbers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Numbers. 1602.19 Section 1602.19 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.19 Numbers. Cardinal numbers may be expressed by Arabic or Roman symbols....

  8. A universal number for wave reflection optimization of the mammalian cardiovascular system.

    NASA Astrophysics Data System (ADS)

    Pahlevan, Niema; Gharib, Morteza

    2015-11-01

    Quantifying the optimum arterial wave reflection and systemic arterial function is essential to the evaluation of optimal cardiovascular system (CVS) operation. The CVS function depends on both the dynamics of the heart and wave dynamics of the arterial network. Here, we are introducing a universal dimensionless number, called wave condition number (α) that quantifies the arterial wave reflection. An in-vitro experimental approach, utilizing a unique hydraulic model was used to quantify α in human aortas with a wide range of aortic rigidities. Our results indicate that the optimum value of the wave condition number is 0.1 at each level of aortic rigidity. Looking into mammals of various size (from mice to elephant), our results show that the optimum wave condition number remains 0.1 and is universal among all mammals. Clinical applications and the relevancy of the wave condition number will also be discussed.

  9. IMPACT OF CAPILLARY AND BOND NUMBERS ON RELATIVE PERMEABILITY

    SciTech Connect

    Kishore K. Mohanty

    2002-09-30

    Recovery and recovery rate of oil, gas and condensates depend crucially on their relative permeability. Relative permeability in turn depends on the pore structure, wettability and flooding conditions, which can be represented by a set of dimensionless groups including capillary and bond numbers. The effect of flooding conditions on drainage relative permeabilities is not well understood and is the overall goal of this project. This project has three specific objectives: to improve the centrifuge relative permeability method, to measure capillary and bond number effects experimentally, and to develop a pore network model for multiphase flows. A centrifuge has been built that can accommodate high pressure core holders and x-ray saturation monitoring. The centrifuge core holders can operate at a pore pressure of 6.9 MPa (1000 psi) and an overburden pressure of 17 MPa (2500 psi). The effect of capillary number on residual saturation and relative permeability in drainage flow has been measured. A pore network model has been developed to study the effect of capillary numbers and viscosity ratio on drainage relative permeability. Capillary and Reynolds number dependence of gas-condensate flow has been studied during well testing. A method has been developed to estimate relative permeability parameters from gas-condensate well test data.

  10. Are Numbers Gendered?

    ERIC Educational Resources Information Center

    Wilkie, James E. B.; Bodenhausen, Galen V.

    2012-01-01

    We examined the possibility that nonsocial, highly generic concepts are gendered. Specifically, we investigated the gender connotations of Arabic numerals. Across several experiments, we show that the number 1 and other odd numbers are associated with masculinity, whereas the number 2 and other even numbers are associated with femininity, in ways…

  11. Building Numbers from Primes

    ERIC Educational Resources Information Center

    Burkhart, Jerry

    2009-01-01

    Prime numbers are often described as the "building blocks" of natural numbers. This article shows how the author and his students took this idea literally by using prime factorizations to build numbers with blocks. In this activity, students explore many concepts of number theory, including the relationship between greatest common factors and…

  12. Enriching Number Knowledge

    ERIC Educational Resources Information Center

    Mack, Nancy K.

    2011-01-01

    Exploring number systems of other cultures can be an enjoyable learning experience that enriches students' knowledge of numbers and number systems in important ways. It helps students deepen mental computation fluency, knowledge of place value, and equivalent representations for numbers. This article describes how the author designed her…

  13. Number Sense Made Simple Using Number Patterns

    ERIC Educational Resources Information Center

    Su, Hui Fang Huang; Marinas, Carol; Furner, Joseph

    2011-01-01

    This article highlights investigating intriguing number patterns utilising an emerging technology called the Square Tool. Mathematics teachers of grades K-12 will find the Square Tool useful in making connections and bridging the gap from the concrete to the abstract. Pattern recognition helps students discover various mathematical concepts. With…

  14. All square chiliagonal numbers

    NASA Astrophysics Data System (ADS)

    Aṣiru, Muniru A.

    2016-10-01

    A square chiliagonal number is a number which is simultaneously a chiliagonal number and a perfect square (just as the well-known square triangular number is both triangular and square). In this work, we determine which of the chiliagonal numbers are perfect squares and provide the indices of the corresponding chiliagonal numbers and square numbers. The study revealed that the determination of square chiliagonal numbers naturally leads to a generalized Pell equation x2 - Dy2 = N with D = 1996 and N = 9962, and has six fundamental solutions out of which only three yielded integer values for use as indices of chiliagonal numbers. The crossing/independent recurrence relations satisfied by each class of indices of the corresponding chiliagonal numbers and square numbers are obtained. Finally, the generating functions serve as a clothesline to hang up the indices of the corresponding chiliagonal numbers and square numbers for easy display and this was used to obtain the first few sequence of square chiliagonal numbers.

  15. Number projection method

    SciTech Connect

    Kaneko, K.

    1987-02-01

    A relationship between the number projection and the shell model methods is investigated in the case of a single-j shell. We can find a one-to-one correspondence between the number projected and the shell model states.

  16. Making decisions from numbers

    SciTech Connect

    Somers, E.

    1987-03-01

    Regulatory agencies require numbers to provide health protection. The manner in which these numbers are derived from animal experiments and human epidemiology is considered together with the limitations and inadequacies of these numbers. Some recent examples of risk assessment in Canada are given including asbestos, drinking water, and indoor air quality. The value of these numbers in providing a measure of the hazard in a wider perspective is stressed, although they can never be the sole determinant of public policy.

  17. The Remarkable Number "1"

    ERIC Educational Resources Information Center

    Allen, G. Donald

    2014-01-01

    In human history, the origin of the numbers came from definite practical needs. Indeed, there is strong evidence that numbers were created before writing. The number "1", dating back at least 20,000 years, was found as a counting symbol on a bone. The famous statement by the German mathematician Leopold Kronecker (1823-1891), "God…

  18. Sum-Difference Numbers

    ERIC Educational Resources Information Center

    Shi, Yixun

    2010-01-01

    Starting with an interesting number game sometimes used by school teachers to demonstrate the factorization of integers, "sum-difference numbers" are defined. A positive integer n is a "sum-difference number" if there exist positive integers "x, y, w, z" such that n = xy = wz and x ? y = w + z. This paper characterizes all sum-difference numbers…

  19. Discovery: Prime Numbers

    ERIC Educational Resources Information Center

    de Mestre, Neville

    2008-01-01

    Prime numbers are important as the building blocks for the set of all natural numbers, because prime factorisation is an important and useful property of all natural numbers. Students can discover them by using the method known as the Sieve of Eratosthenes, named after the Greek geographer and astronomer who lived from c. 276-194 BC. Eratosthenes…

  20. Estimating Large Numbers

    ERIC Educational Resources Information Center

    Landy, David; Silbert, Noah; Goldin, Aleah

    2013-01-01

    Despite their importance in public discourse, numbers in the range of 1 million to 1 trillion are notoriously difficult to understand. We examine magnitude estimation by adult Americans when placing large numbers on a number line and when qualitatively evaluating descriptions of imaginary geopolitical scenarios. Prior theoretical conceptions…

  1. Number Relationships in Preschool

    ERIC Educational Resources Information Center

    Jung, Myoungwhon

    2011-01-01

    When a child understands number relationships, he or she comprehends the meaning of numbers by developing multiple, flexible ways of representing them. The importance of developing number relationships in the early years has been highlighted because it helps children build a good foundation for developing a more sophisticated understanding of…

  2. Flying and swimming animals cruise at a Strouhal number tuned for high power efficiency.

    PubMed

    Taylor, Graham K; Nudds, Robert L; Thomas, Adrian L R

    2003-10-16

    Dimensionless numbers are important in biomechanics because their constancy can imply dynamic similarity between systems, despite possible differences in medium or scale. A dimensionless parameter that describes the tail or wing kinematics of swimming and flying animals is the Strouhal number, St = fA/U, which divides stroke frequency (f) and amplitude (A) by forward speed (U). St is known to govern a well-defined series of vortex growth and shedding regimes for airfoils undergoing pitching and heaving motions. Propulsive efficiency is high over a narrow range of St and usually peaks within the interval 0.2 < St < 0.4 (refs 3-8). Because natural selection is likely to tune animals for high propulsive efficiency, we expect it to constrain the range of St that animals use. This seems to be true for dolphins, sharks and bony fish, which swim at 0.2 < St < 0.4. Here we show that birds, bats and insects also converge on the same narrow range of St, but only when cruising. Tuning cruise kinematics to optimize St therefore seems to be a general principle of oscillatory lift-based propulsion.

  3. Flying and swimming animals cruise at a Strouhal number tuned for high power efficiency.

    PubMed

    Taylor, Graham K; Nudds, Robert L; Thomas, Adrian L R

    2003-10-16

    Dimensionless numbers are important in biomechanics because their constancy can imply dynamic similarity between systems, despite possible differences in medium or scale. A dimensionless parameter that describes the tail or wing kinematics of swimming and flying animals is the Strouhal number, St = fA/U, which divides stroke frequency (f) and amplitude (A) by forward speed (U). St is known to govern a well-defined series of vortex growth and shedding regimes for airfoils undergoing pitching and heaving motions. Propulsive efficiency is high over a narrow range of St and usually peaks within the interval 0.2 < St < 0.4 (refs 3-8). Because natural selection is likely to tune animals for high propulsive efficiency, we expect it to constrain the range of St that animals use. This seems to be true for dolphins, sharks and bony fish, which swim at 0.2 < St < 0.4. Here we show that birds, bats and insects also converge on the same narrow range of St, but only when cruising. Tuning cruise kinematics to optimize St therefore seems to be a general principle of oscillatory lift-based propulsion. PMID:14562101

  4. Hierarchical number estimation.

    PubMed

    Friedenberg, Jay; Limratana, William

    2005-01-01

    We investigated number estimation using dot patterns grouped by proximity into larger clusters. Participants estimated the number of dots and clusters in separate trials. Estimation was most accurate when the numbers of elements on both scales were the same. When the number of elements on the unattended scale was higher, overestimation occurred. Conversely, when the number of elements on the unattended scale was lower, underestimation occurred. In Experiment 2, response cues were blocked to reduce any tendency toward attending the irrelevant level. The results were essentially unchanged, indicating response confusion alone cannot account for the effect. The data support the existence of an opposite scale effect in which the number of elements at the unattended level influence the processing of number.

  5. The Soybean Rhg1 Locus for Resistance to the Soybean Cyst Nematode Heterodera glycines Regulates the Expression of a Large Number of Stress- and Defense-Related Genes in Degenerating Feeding Cells1[C][W][OA

    PubMed Central

    Kandoth, Pramod Kaitheri; Ithal, Nagabhushana; Recknor, Justin; Maier, Tom; Nettleton, Dan; Baum, Thomas J.; Mitchum, Melissa G.

    2011-01-01

    To gain new insights into the mechanism of soybean (Glycine max) resistance to the soybean cyst nematode (Heterodera glycines), we compared gene expression profiles of developing syncytia in soybean near-isogenic lines differing at Rhg1 (for resistance to Heterodera glycines), a major quantitative trait locus for resistance, by coupling laser capture microdissection with microarray analysis. Gene expression profiling revealed that 1,447 genes were differentially expressed between the two lines. Of these, 241 (16.8%) were stress- and defense-related genes. Several stress-related genes were up-regulated in the resistant line, including those encoding homologs of enzymes that lead to increased levels of reactive oxygen species and proteins associated with the unfolded protein response. These results indicate that syncytia induced in the resistant line are undergoing severe oxidative stress and imbalanced endoplasmic reticulum homeostasis, both of which likely contribute to the resistance reaction. Defense-related genes up-regulated within syncytia of the resistant line included those predominantly involved in apoptotic cell death, the plant hypersensitive response, and salicylic acid-mediated defense signaling; many of these genes were either partially suppressed or not induced to the same level by a virulent soybean cyst nematode population for successful nematode reproduction and development on the resistant line. Our study demonstrates that a network of molecular events take place during Rhg1-mediated resistance, leading to a highly complex defense response against a root pathogen. PMID:21335526

  6. Curvature and Tachibana numbers

    SciTech Connect

    Stepanov, Sergey E

    2011-07-31

    The aim of this paper is to define the rth Tachibana number t{sub r} of an n-dimensional compact oriented Riemannian manifold as the dimension of the space of conformally Killing r-forms, for r=1,2,...,n-1. We also describe properties of these numbers, by analogy with properties of the Betti numbers b{sub r} of a compact oriented Riemannian manifold. Bibliography: 25 titles.

  7. High Reynolds Number Research

    NASA Technical Reports Server (NTRS)

    Baals, D. D. (Editor)

    1977-01-01

    Fundamental aerodynamic questions for which high Reynolds number experimental capability is required are discussed. The operational characteristics and design features of the National Transonic Facility are reviewed.

  8. Genetics by the Numbers

    MedlinePlus

    ... Life Science > Genetics by the Numbers Inside Life Science View All Articles | Inside Life Science Home Page Genetics by the Numbers By Chelsea ... Genetics NIH's National DNA Day This Inside Life Science article also appears on LiveScience . Learn about related ...

  9. The Fibonacci Numbers.

    ERIC Educational Resources Information Center

    Onstad, Torgeir

    1991-01-01

    After a brief historical account of Leonardo Pisano Fibonacci, some basic results concerning the Fibonacci numbers are developed and proved, and entertaining examples are described. Connections are made between the Fibonacci numbers and the Golden Ratio, biological nature, and other combinatorics examples. (MDH)

  10. Templates, Numbers & Watercolors.

    ERIC Educational Resources Information Center

    Clemesha, David J.

    1990-01-01

    Describes how a second-grade class used large templates to draw and paint five-digit numbers. The lesson integrated artistic knowledge and vocabulary with their mathematics lesson in place value. Students learned how draftspeople use templates, and they studied number paintings by Charles Demuth and Jasper Johns. (KM)

  11. Avogadro's Number Ferromagnetically

    ERIC Educational Resources Information Center

    Houari, Ahmed

    2010-01-01

    Avogadro's number, usually denoted by N[subscript A], plays a fundamental role in both physics and chemistry. It defines the extremely useful concept of the mole, which is the base unit of the amount of matter in the international system of units. The fundamental character of this number can also be illustrated by its appearance in the definitions…

  12. Numbers in Action

    PubMed Central

    Rugani, Rosa; Sartori, Luisa

    2016-01-01

    Humans show a remarkable tendency to describe and think of numbers as being placed on a mental number line (MNL), with smaller numbers located on the left and larger ones on the right. Faster responses to small numbers are indeed performed on the left side of space, while responses to large numbers are facilitated on the right side of space (spatial-numerical association of response codes, SNARC effect). This phenomenon is considered the experimental demonstration of the MNL and has been extensively replicated throughout a variety of paradigms. Nevertheless, the majority of previous literature has mainly investigated this effect by means of response times and accuracy, whereas studies considering more subtle and automatic measures such as kinematic parameters are rare (e.g., in a reaching-to-grasp movement, the grip aperture is enlarged in responding to larger numbers than in responding to small numbers). In this brief review we suggest that numerical magnitude can also affect the what and how of action execution (i.e., temporal and spatial components of movement). This evidence could have large implications in the strongly debated issue concerning the effect of experience and culture on the orientation of MNL. PMID:27524965

  13. High-Reynolds Number Taylor-Couette Turbulence

    NASA Astrophysics Data System (ADS)

    Grossmann, Siegfried; Lohse, Detlef; Sun, Chao

    2016-01-01

    Taylor-Couette flow, the flow between two coaxial co- or counter-rotating cylinders, is one of the paradigmatic systems in the physics of fluids. The (dimensionless) control parameters are the Reynolds numbers of the inner and outer cylinders, the ratio of the cylinder radii, and the aspect ratio. One key response of the system is the torque required to retain constant angular velocities, which can be connected to the angular velocity transport through the gap. Whereas the low-Reynolds number regime was well explored in the 1980s and 1990s of the past century, in the fully turbulent regime major research activity developed only in the past decade. In this article, we review this recent progress in our understanding of fully developed Taylor-Couette turbulence from the experimental, numerical, and theoretical points of view. We focus on the parameter dependence of the global torque and on the local flow organization, including velocity profiles and boundary layers. Next, we discuss transitions between different (turbulent) flow states. We also elaborate on the relevance of this system for astrophysical disks (quasi-Keplerian flows). The review ends with a list of challenges for future research on turbulent Taylor-Couette flow.

  14. Logo and Negative Numbers.

    ERIC Educational Resources Information Center

    Strawn, Candace A.

    1998-01-01

    Describes LOGO's turtle graphics capabilities based on a sixth-grade classroom's activities with negative numbers and Logo programming. A sidebar explains LOGO and offers suggestions to teachers for using LOGO effectively. (LRW)

  15. The Numbers Game.

    ERIC Educational Resources Information Center

    Lustick, David

    1997-01-01

    Describes a simple activity that explores and reveals the principles of significant figures and scientific notation using a 500 gram bag of unpopped popcorn. Students must devise a method for determining the number of kernels in the bag. (DDR)

  16. Nursing by numbers.

    PubMed

    Hurst, Keith

    In the face of NHS budget cuts, nurses are being asked to justify their workforce numbers. Keith Hurst reviews some of the tools available for calculating staffing levels, examines their pros and cons, and discusses their application. PMID:17087410

  17. Quantum random number generator

    DOEpatents

    Pooser, Raphael C.

    2016-05-10

    A quantum random number generator (QRNG) and a photon generator for a QRNG are provided. The photon generator may be operated in a spontaneous mode below a lasing threshold to emit photons. Photons emitted from the photon generator may have at least one random characteristic, which may be monitored by the QRNG to generate a random number. In one embodiment, the photon generator may include a photon emitter and an amplifier coupled to the photon emitter. The amplifier may enable the photon generator to be used in the QRNG without introducing significant bias in the random number and may enable multiplexing of multiple random numbers. The amplifier may also desensitize the photon generator to fluctuations in power supplied thereto while operating in the spontaneous mode. In one embodiment, the photon emitter and amplifier may be a tapered diode amplifier.

  18. Fibonacci's Forgotten Number

    ERIC Educational Resources Information Center

    Brown, Ezra; Brunson, Cornelius

    2008-01-01

    Fibonacci's forgotten number is the sexagesimal number 1;22,7,42,33,4,40, which he described in 1225 as an approximation to the real root of x[superscript 3] + 2x[superscript 2] + 10x - 20. In decimal notation, this is 1.36880810785...and it is correct to nine decimal digits. Fibonacci did not reveal his method. How did he do it? There is also a…

  19. Details of Exact Low Prandtl Number Boundary-Layer Solutions for Forced and For Free Convection

    NASA Technical Reports Server (NTRS)

    Sparrow, E. M.; Gregg, J. L.

    1959-01-01

    A detailed report is given of exact (numerical) solutions of the laminar-boundary-layer equations for the Prandtl number range appropriate to liquid metals (0.003 to 0.03). Consideration is given to the following situations: (1) forced convection over a flat plate for the conditions of uniform wall temperature and uniform wall heat flux, and (2) free convection over an isothermal vertical plate. Tabulations of the new solutions are given in detail. Results are presented for the heat-transfer and shear-stress characteristics; temperature and velocity distributions are also shown. The heat-transfer results are correlated in terms of dimensionless parameters that vary only slightly over the entire liquid-metal range. Previous analytical and experimental work on low Prandtl number boundary layers is surveyed and compared with the new exact solutions.

  20. [Projection of prisoner numbers].

    PubMed

    Metz, Rainer; Sohn, Werner

    2015-01-01

    The past and future development of occupancy rates in prisons is of crucial importance for the judicial administration of every country. Basic factors for planning the required penal facilities are seasonal fluctuations, minimum, maximum and average occupancy as well as the present situation and potential development of certain imprisonment categories. As the prisoner number of a country is determined by a complex set of interdependent conditions, it has turned out to be difficult to provide any theoretical explanations. The idea accepted in criminology for a long time that prisoner numbers are interdependent with criminal policy must be regarded as having failed. Statistical and time series analyses may help, however, to identify the factors having influenced the development of prisoner numbers in the past. The analyses presented here, first describe such influencing factors from a criminological perspective and then deal with their statistical identification and modelling. Using the development of prisoner numbers in Hesse as an example, it has been found that modelling methods in which the independent variables predict the dependent variable with a time lag are particularly helpful. A potential complication is, however, that for predicting the number of prisoners the different dynamics in German and foreign prisoners require the development of further models. PMID:26419083

  1. Report number codes

    SciTech Connect

    Nelson, R.N.

    1985-05-01

    This publication lists all report number codes processed by the Office of Scientific and Technical Information. The report codes are substantially based on the American National Standards Institute, Standard Technical Report Number (STRN)-Format and Creation Z39.23-1983. The Standard Technical Report Number (STRN) provides one of the primary methods of identifying a specific technical report. The STRN consists of two parts: The report code and the sequential number. The report code identifies the issuing organization, a specific program, or a type of document. The sequential number, which is assigned in sequence by each report issuing entity, is not included in this publication. Part I of this compilation is alphabetized by report codes followed by issuing installations. Part II lists the issuing organization followed by the assigned report code(s). In both Parts I and II, the names of issuing organizations appear for the most part in the form used at the time the reports were issued. However, for some of the more prolific installations which have had name changes, all entries have been merged under the current name.

  2. Beyond the Number Domain

    PubMed Central

    Cantlon, Jessica F.; Platt, Michael L.; Brannon, Elizabeth M.

    2009-01-01

    In a world without numbers, we would be unable to build a skyscraper, hold a national election, plan a wedding, or pay for a chicken at the market. The numerical symbols used in all these behaviors build on the approximate number system (ANS) which represents the number of discrete objects or events as a continuous mental magnitude. In this review, we first discuss evidence that the ANS bears a set of behavioral and brain signatures that are universally displayed across animal species, human cultures, and development. We then turn to the question of whether the ANS constitutes a specialized cognitive and neural domain--a question central to understanding how this system works, the nature of its evolutionary and developmental trajectory, and its physical instantiation in the brain. PMID:19131268

  3. Quantum random number generation

    DOE PAGESBeta

    Ma, Xiongfeng; Yuan, Xiao; Cao, Zhu; Zhang, Zhen; Qi, Bing

    2016-06-28

    Here, quantum physics can be exploited to generate true random numbers, which play important roles in many applications, especially in cryptography. Genuine randomness from the measurement of a quantum system reveals the inherent nature of quantumness -- coherence, an important feature that differentiates quantum mechanics from classical physics. The generation of genuine randomness is generally considered impossible with only classical means. Based on the degree of trustworthiness on devices, quantum random number generators (QRNGs) can be grouped into three categories. The first category, practical QRNG, is built on fully trusted and calibrated devices and typically can generate randomness at amore » high speed by properly modeling the devices. The second category is self-testing QRNG, where verifiable randomness can be generated without trusting the actual implementation. The third category, semi-self-testing QRNG, is an intermediate category which provides a tradeoff between the trustworthiness on the device and the random number generation speed.« less

  4. High Reynolds number and turbulence effects on aerodynamics and heat transfer in a turbine cascade

    NASA Technical Reports Server (NTRS)

    Yeh, Frederick C.; Hippensteele, Steven A.; Vanfossen, G. James; Poinsatte, Philip E.; Ameri, Ali

    1993-01-01

    Experimental data on pressure distribution and heat transfer on a turbine airfoil were obtained over a range of Reynolds numbers from 0.75 to 7.5 x 10 exp 6 and a range of turbulence intensities from 1.8 to about 15 percent. The purpose of this study was to obtain fundamental heat transfer and pressure distribution data over a wide range of high Reynolds numbers and to extend the heat transfer data base to include the range of Reynolds numbers encountered in the Space Shuttle main engine (SSME) turbopump turbines. Specifically, the study aimed to determine (1) the effect of Reynolds number on heat transfer, (2) the effect of upstream turbulence on heat transfer and pressure distribution, and (3) the relationship between heat transfer at high Reynolds numbers and the current data base. The results of this study indicated that Reynolds number and turbulence intensity have a large effect on both the transition from laminar to turbulent flow and the resulting heat transfer. For a given turbulence intensity, heat transfer for all Reynolds numbers at the leading edge can be correlated with the Frossling number developed for lower Reynolds numbers. For a given turbulence intensity, heat transfer for the airfoil surfaces downstream of the leading edge can be approximately correlated with a dimensionless parameter. Comparison of the experimental results were also made with a numerical solution from a two-dimensional Navier-Stokes code.

  5. Density distribution of free fatty acid receptor 2 (FFA2)-expressing and GLP-1-producing enteroendocrine L cells in human and rat lower intestine, and increased cell numbers after ingestion of fructo-oligosaccharide.

    PubMed

    Kaji, Izumi; Karaki, Shin-Ichiro; Tanaka, Ryo; Kuwahara, Atsukazu

    2011-02-01

    Glucagon-like peptide 1 (GLP-1) is a multifunctional hormone in glucose metabolism and intestinal function released by enteroendocrine L-cells. The plasma concentration of GLP-1 is increased by indigestible carbohydrates and luminal infusion of short-chain fatty acids (SCFAs). However, the triggers and modulators of the GLP-1 release remain unclear. We hypothesized that SCFAs produced by bacterial fermentation are involved in enteroendocrine cell proliferation and hormone release through free fatty acid receptor 2 (FFA2, also known as FFAR2 or GPR43) in the large intestine. Fructo-oligosaccharide (Fructo-OS), fermentable indigestible carbohydrate, was used as a source of SCFAs. Rats were fed an indigestible-carbohydrate-free diet (control) or a 5% Fructo-OS-containing diet for 28 days. FFA2-, GLP-1-, and 5-hydroxytryptamine (5-HT)-positive enteroendocrine cells were quantified immunohistochemically in the colon, cecum, and terminal ileum. The same analysis was performed in surgical specimens from human lower intestine. The coexpression of FFA2 with GLP-1 was investigated both in rats and humans. Fructo-OS supplementation in rats increased the densities of FFA2-positive enteroendocrine cells in rat proximal colon, by over two-fold, relative to control, in parallel with GLP-1-containing L-cells. The segmental distributions of these cells in human were similar to rats fed the control diet. The FFA2-positive enteroendocrine cells were GLP-1-containing L-cells, but not 5-HT-containing EC cells, in both human and rat colon and terminal ileum. Fermentable indigestible carbohydrate increases the number of FFA2-positive L-cells in the proximal colon. FFA2 activation by SCFAs might be an important trigger for produce and release GLP-1 by enteroendocrine L-cells in the lower intestine.

  6. Loss of Vascular Endothelial Growth Factor A (VEGFA) Isoforms in the Testes of Male Mice Causes Subfertility, Reduces Sperm Numbers, and Alters Expression of Genes That Regulate Undifferentiated Spermatogonia

    PubMed Central

    Lu, Ningxia; Sargent, Kevin M.; Clopton, Debra T.; Pohlmeier, William E.; Brauer, Vanessa M.; McFee, Renee M.; Weber, John S.; Ferrara, Napoleone; Silversides, David W.

    2013-01-01

    Vascular endothelial growth factor A (VEGFA) isoform treatment has been demonstrated to alter spermatogonial stem cell homeostasis. Therefore, we generated pDmrt1-Cre;Vegfa−/− (knockout, KO) mice by crossing pDmrt1-Cre mice to floxed Vegfa mice to test whether loss of all VEGFA isoforms in Sertoli and germ cells would impair spermatogenesis. When first mated, KO males took 14 days longer to get control females pregnant (P < .02) and tended to take longer for all subsequent parturition intervals (9 days; P < .07). Heterozygous males sired fewer pups per litter (P < .03) and after the first litter took 10 days longer (P < .05) to impregnate females, suggesting a more progressive loss of fertility. Reproductive organs were collected from 6-month-old male mice. There were fewer sperm per tubule in the corpus epididymides (P < .001) and fewer ZBTB16-stained undifferentiated spermatogonia (P < .003) in the testes of KO males. Testicular mRNA abundance for Bcl2 (P < .02), Bcl2:Bax (P < .02), Neurog3 (P < .007), and Ret was greater (P = .0005), tended to be greater for Sin3a and tended to be reduced for total Foxo1 (P < .07) in KO males. Immunofluorescence for CD31 and VE-Cadherin showed no differences in testis vasculature; however, CD31-positive staining was evident in undifferentiated spermatogonia only in KO testes. Therefore, loss of VEGFA isoforms in Sertoli and germ cells alters genes necessary for long-term maintenance of undifferentiated spermatogonia, ultimately reducing sperm numbers and resulting in subfertility. PMID:24169552

  7. ALARA notes, Number 8

    SciTech Connect

    Khan, T.A.; Baum, J.W.; Beckman, M.C.

    1993-10-01

    This document contains information dealing with the lessons learned from the experience of nuclear plants. In this issue the authors tried to avoid the `tyranny` of numbers and concentrated on the main lessons learned. Topics include: filtration devices for air pollution abatement, crack repair and inspection, and remote handling equipment.

  8. Paint by Numbers Revived!

    ERIC Educational Resources Information Center

    Hahn, Nic

    2012-01-01

    Remember paint by numbers? This revived trend was a perfect solution to teaching geometric shapes to the author's first-grade students. Geometric shapes are identified and used in early elementary art classrooms, but this lesson gives students a deeper understanding of shape, encourages problem-solving, and makes a strong correlation between math…

  9. Introducing Complex Numbers

    ERIC Educational Resources Information Center

    Trudgian, Timothy

    2009-01-01

    One of the difficulties in any teaching of mathematics is to bridge the divide between the abstract and the intuitive. Throughout school one encounters increasingly abstract notions, which are more and more difficult to relate to everyday experiences. This article examines a familiar approach to thinking about negative numbers, that is an…

  10. Uniform random number generators

    NASA Technical Reports Server (NTRS)

    Farr, W. R.

    1971-01-01

    Methods are presented for the generation of random numbers with uniform and normal distributions. Subprogram listings of Fortran generators for the Univac 1108, SDS 930, and CDC 3200 digital computers are also included. The generators are of the mixed multiplicative type, and the mathematical method employed is that of Marsaglia and Bray.

  11. The Net by Numbers.

    ERIC Educational Resources Information Center

    McMurdo, George

    1996-01-01

    The expansion of the commercial Internet has encouraged the interpretation of the Internet and its uses as a potential marketing medium. Examines statistical and demographic information about the Internet including number of Internet hosts and World Wide Web servers, and estimates of Internet users; and raises questions about definitions and…

  12. "Better than Their Numbers"

    ERIC Educational Resources Information Center

    Cech, Scott J.

    2008-01-01

    This article discusses College Summit, a nonprofit effort centered around the premise that there is a sizable number of students who are more capable of college academics than their test scores and grade point averages suggest. Its four-day summer sessions are focused not on ramping up students' academic performance but in mining students'…

  13. Number in Classifier Languages

    ERIC Educational Resources Information Center

    Nomoto, Hiroki

    2013-01-01

    Classifier languages are often described as lacking genuine number morphology and treating all common nouns, including those conceptually count, as an unindividuated mass. This study argues that neither of these popular assumptions is true, and presents new generalizations and analyses gained by abandoning them. I claim that no difference exists…

  14. Characteristic Numbers of Matrix Lie Algebras

    NASA Astrophysics Data System (ADS)

    Zhang, Yu-Feng; Fan, En-Gui

    2008-04-01

    A notion of characteristic number of matrix Lie algebras is defined, which is devoted to distinguishing various Lie algebras that are used to generate integrable couplings of soliton equations. That is, the exact classification of the matrix Lie algebras by using computational formulas is given. Here the characteristic numbers also describe the relations between soliton solutions of the stationary zero curvature equations expressed by various Lie algebras.

  15. Fun with Safronov Numbers

    NASA Astrophysics Data System (ADS)

    Christian, Damian Joseph; Lund, M. B.

    2010-10-01

    A growing number (over 100!) of extra-solar planets (ESPs) have been discovered by transit photometry, and these systems are important because the transit strongly constrains their orbital inclination and allows accurate physical parameters for the planet to be derived, especially their radii. Their mass-radius relation allows us to probe their internal structure. In the present work we calculate Safronov numbers for the current sample of ESP and compare their masses and radii to current models with the goal of obtaining better constrains on their formation processes. Our calculation of Safronov numbers for the current TESP sample does show 2 classes, although about 20% lie above the formal Class I definition. These trends and recent results that argue against a useful distinction between Safronov classes are under further investigation. Mass-radius relations for the current sample of TESP are inconsistent with ESP models with very large core masses (> 100 M_Earth). Most TESP with radii near 1R_J are consistent with models with no core mass or core masses of 10 M_Earth. The inflated planets, with radii >1.2 R_J are not consistent with current ESP models, but may lie along the lower end of models for brown dwarfs. Although such models are nascent, it is important to establish trends for the current sample of ESP, which will further the understanding of their formation and evolution.

  16. The Remarkable Number "1"

    NASA Astrophysics Data System (ADS)

    Allen, G. Donald

    2014-09-01

    In human history, the origin of the numbers came from definite practical needs. Indeed, there is strong evidence that numbers were created before writing. The number "1", dating back at least 20,000 years, was found as a counting symbol on a bone. The famous statement by the German mathematician Leopold Kronecker (1823-1891), "God made the integers; all else is the work of man," has spawned a lively modern philosophical discussion, and this discussion begins by trying to get a philosophical handle on "1." This approach remains under heavy discussion, and is more-or-less unresolved (Frege in Die Grundlagen der Arithmetik (English: The foundations of arithmetic). Polhman, 1884). In this note, we consider the many facets of "one" in it many guises and applications. Nonetheless, "one" has multiple meanings, from the very practical to the abstract, from mathematics to science to basically everything. We examine here a mere slice of mathematical history with a focus on the most basic and applicable concept therein. It troubles many, particularly students, even today.

  17. Rare Copy Number Variants

    PubMed Central

    Grozeva, Detelina; Kirov, George; Ivanov, Dobril; Jones, Ian R.; Jones, Lisa; Green, Elaine K.; St Clair, David M.; Young, Allan H.; Ferrier, Nicol; Farmer, Anne E.; McGuffin, Peter; Holmans, Peter A.; Owen, Michael J.; O’Donovan, Michael C.; Craddock, Nick

    2015-01-01

    Context Recent studies suggest that copy number variation in the human genome is extensive and may play an important role in susceptibility to disease, including neuropsychiatric disorders such as schizophrenia and autism. The possible involvement of copy number variants (CNVs) in bipolar disorder has received little attention to date. Objectives To determine whether large (>100 000 base pairs) and rare (found in <1% of the population) CNVs are associated with susceptibility to bipolar disorder and to compare with findings in schizophrenia. Design A genome-wide survey of large, rare CNVs in a case-control sample using a high-density microarray. Setting The Wellcome Trust Case Control Consortium. Participants There were 1697 cases of bipolar disorder and 2806 nonpsychiatric controls. All participants were white UK residents. Main Outcome Measures Overall load of CNVs and presence of rare CNVs. Results The burden of CNVs in bipolar disorder was not increased compared with controls and was significantly less than in schizophrenia cases. The CNVs previously implicated in the etiology of schizophrenia were not more common in cases with bipolar disorder. Conclusions Schizophrenia and bipolar disorder differ with respect to CNV burden in general and association with specific CNVs in particular. Our data are consistent with the possibility that possession of large, rare deletions may modify the phenotype in those at risk of psychosis: those possessing such events are more likely to be diagnosed as having schizophrenia, and those without them are more likely to be diagnosed as having bipolar disorder. PMID:20368508

  18. High Reynolds Number Effects on Multi-Hole Probes and Hot Wire Anemometers

    NASA Technical Reports Server (NTRS)

    Ramachandran, N.; Smith, A.; Gerry, G.; Kauffman, W.

    1995-01-01

    The paper reports on the results from an experimental investigation of the response of multi-hole and hot wire probes at high flow Reynolds numbers (Re approx. 10(exp 6)). The limited results available in literature for 5-hole probes are restricted to Re approx. 10(exp 4). The experiment aims to investigate the probe response (in terms of dimensionless pressure ratios, characterizing pitch, and yaw angles and the total and static pressures) at high Re values and to gauge their effect on the calculated velocity vector. Hot wire calibrations were also undertaken with a parametric variation of the flow pressure, velocity and temperature. Different correction and calibration schemes are sought to be tested against the acquired data set. The data is in the analysis stage at the present time. The test provided good benchmark quality data that can be used to test future calibration and testing methods.

  19. An introduction to hyperharmonic numbers

    NASA Astrophysics Data System (ADS)

    Cereceda, José Luis

    2015-04-01

    In this note, we deal with a generalization of the harmonic numbers proposed by Conway and Guy in their Book of Numbers, namely, the so-called hyperharmonic numbers. Our main aim is to prove, by mathematical induction, the formula defining the hyperharmonic numbers in terms of ordinary harmonic numbers. Moreover, we calculate the hyperharmonic numbers as the derivative of a certain binomial coefficient.

  20. CRC octane number requirement survey 1992

    SciTech Connect

    Not Available

    1993-08-01

    An annual statistical survey of octane number requirements of current model vehicles is conducted by the Coordinating Research Council, Inc. Test data have been obtained by ten companies on 184 1992 vehicles including passenger cars and light-duty trucks and vans, of which 88 were equipped with knock sensors. Octane number requirements were determined by testing at maximum-throttle conditions, as well as at part-throttle, with four unleaded fuel series of varying sensitivities, one containing 15 percent methyl tertiary butyl ether. Requirements are expressed as the (R+M)/2 octane number, Research octane number, and Motor octane number of the reference fuel producing knock which was recurrent and repeatable at the lowest audible level. Estimated octane number requirements for the total vehicles are weighted in proportion to the 1992 vehicle model production and/or sales figures. The octane number requirements of 1992 models with average sensitivity unleaded fuels were 85.1 (R+M)/2 octane numbers at the 50 percent satisfaction level, and 92.0 (R+M)/2 octane numbers at the 90 percent satisfaction level. In order to make a more powerful test of statistical significance of the FBRUM fuel series, the 1991 ONRS was pooled with the 1992 ONRS and compared with the pooled data for the FBRU fuel series. There was no significant difference between the two fuel series up to about 90 percent satisfaction. Beyond 90 percent satisfaction, the variability in the data is high.

  1. CRC octane-number-requirement survey, 1990

    SciTech Connect

    Not Available

    1991-07-01

    An annual statistical survey of octane number requirements of current model vehicles is conducted by the Coordinating Research Council, Inc. Test data have been obtained by seventeen companies on 356 1990 vehicles including passenger cars and light-duty trucks and vans, of which 169 were equipped with knock sensors. Octane number requirements were determined by testing at maximum-throttle conditions, as well as at part-throttle, with three unleaded fuel series of varying sensitivities. Requirements are expressed as the (R+M)/2 octane number, Research octane number, and Motor octane number of the reference fuel producing knock which was recurrent and repeatable at the lowest audible level. Estimated octane number requirements for the total vehicles are weighted in proportion to the 1990 vehicle model production and/or sales figures. The octane number requirements of 1990 models with average sensitivity unleaded fuels were 85.4 (R+M)/2 octane numbers at the 50 percent satisfaction level, and 89.2 (R+M)/2 octane numbers at the 90 percent satisfaction level.

  2. CRC octane number requirement survey for 1989

    SciTech Connect

    Not Available

    1990-08-01

    An annual statistical survey of octane number requirements of current model vehicles is conducted by the Coordinating Research Council, Inc. Test data have been obtained by eighteen companies on 391 1989 vehicles including passenger cars and light-duty trucks and vans, of which 179 were equipped with knock sensors. Maximum octane number requirements were determined by testing at maximum-throttle conditions, as well as at part-throttle, with three unleaded fuel series of varying sensitivities. Requirements are expressed as the (R+M)/2 octane number, Research octane number, and Motor octane number of the reference fuel producing knock which was recurrent and repeatable at the lowest audible level. Estimated octane number requirements for the total vehicles are weighted in proportion to the 1989 vehicle model production and/or sales figures. The maximum octane number requirements of 1989 models with average sensitivity unleaded fuels were 85.1 (R+M)/2 octane numbers at the 50 percent satisfaction level, and 89.2 (R+M)/2 octane numbers at the 90 percent satisfaction level. Comparison with previous Surveys are made in this report.

  3. 7 CFR 29.9205 - Identification number (farm serial number).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Identification number (farm serial number). 29.9205 Section 29.9205 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE... number (farm serial number). The serial number assigned to an individual farm by the appropriate...

  4. 7 CFR 29.9205 - Identification number (farm serial number).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Identification number (farm serial number). 29.9205 Section 29.9205 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE... number (farm serial number). The serial number assigned to an individual farm by the appropriate...

  5. Importance of wave-number dependence of Biot numbers in one-sided models of evaporative Marangoni instability: Horizontal layer and spherical droplet

    NASA Astrophysics Data System (ADS)

    Machrafi, H.; Rednikov, A.; Colinet, P.; Dauby, P. C.

    2015-05-01

    A one-sided model of the thermal Marangoni instability owing to evaporation into an inert gas is developed. Two configurations are studied in parallel: a horizontal liquid layer and a spherical droplet. With the dynamic gas properties being admittedly negligible, one-sided approaches typically hinge upon quantifying heat and mass transfer through the gas phase by means of transfer coefficients (like in the Newton's cooling law), which in dimensionless terms eventually corresponds to using Biot numbers. Quite a typical arrangement encountered in the literature is a constant Biot number, the same for perturbations of different wavelengths and maybe even the same as for the reference state. In the present work, we underscore the relevance of accounting for its wave-number dependence, which is especially the case in the evaporative context with relatively large values of the resulting effective Biot number. We illustrate the effect in the framework of the Marangoni instability thresholds. As a concrete example, we consider HFE-7100 (a standard refrigerant) for the liquid and air for the inert gas.

  6. Importance of wave-number dependence of Biot numbers in one-sided models of evaporative Marangoni instability: Horizontal layer and spherical droplet.

    PubMed

    Machrafi, H; Rednikov, A; Colinet, P; Dauby, P C

    2015-05-01

    A one-sided model of the thermal Marangoni instability owing to evaporation into an inert gas is developed. Two configurations are studied in parallel: a horizontal liquid layer and a spherical droplet. With the dynamic gas properties being admittedly negligible, one-sided approaches typically hinge upon quantifying heat and mass transfer through the gas phase by means of transfer coefficients (like in the Newton's cooling law), which in dimensionless terms eventually corresponds to using Biot numbers. Quite a typical arrangement encountered in the literature is a constant Biot number, the same for perturbations of different wavelengths and maybe even the same as for the reference state. In the present work, we underscore the relevance of accounting for its wave-number dependence, which is especially the case in the evaporative context with relatively large values of the resulting effective Biot number. We illustrate the effect in the framework of the Marangoni instability thresholds. As a concrete example, we consider HFE-7100 (a standard refrigerant) for the liquid and air for the inert gas.

  7. Beyond natural numbers: negative number representation in parietal cortex.

    PubMed

    Blair, Kristen P; Rosenberg-Lee, Miriam; Tsang, Jessica M; Schwartz, Daniel L; Menon, Vinod

    2012-01-01

    Unlike natural numbers, negative numbers do not have natural physical referents. How does the brain represent such abstract mathematical concepts? Two competing hypotheses regarding representational systems for negative numbers are a rule-based model, in which symbolic rules are applied to negative numbers to translate them into positive numbers when assessing magnitudes, and an expanded magnitude model, in which negative numbers have a distinct magnitude representation. Using an event-related functional magnetic resonance imaging design, we examined brain responses in 22 adults while they performed magnitude comparisons of negative and positive numbers that were quantitatively near (difference <4) or far apart (difference >6). Reaction times (RTs) for negative numbers were slower than positive numbers, and both showed a distance effect whereby near pairs took longer to compare. A network of parietal, frontal, and occipital regions were differentially engaged by negative numbers. Specifically, compared to positive numbers, negative number processing resulted in greater activation bilaterally in intraparietal sulcus (IPS), middle frontal gyrus, and inferior lateral occipital cortex. Representational similarity analysis revealed that neural responses in the IPS were more differentiated among positive numbers than among negative numbers, and greater differentiation among negative numbers was associated with faster RTs. Our findings indicate that despite negative numbers engaging the IPS more strongly, the underlying neural representation are less distinct than that of positive numbers. We discuss our findings in the context of the two theoretical models of negative number processing and demonstrate how multivariate approaches can provide novel insights into abstract number representation.

  8. Percents Are Not Natural Numbers

    ERIC Educational Resources Information Center

    Jacobs, Jennifer A.

    2013-01-01

    Adults are prone to treating percents, one representational format of rational numbers, as novel cases of natural number. This suggests that percent values are not differentiated from natural numbers; a conceptual shift from the natural numbers to the rational numbers has not yet occurred. This is most surprising, considering people are inundated…

  9. Low Reynolds number multiple-time-scale turbulence model and calculations of steady and pulsating shear layers

    NASA Technical Reports Server (NTRS)

    Kim, Sang-Wook

    1992-01-01

    A low Reynolds number multiple-time-scale turbulence model (LMS) and its application to fully developed turbulent channel flows and pulsating pipe flows are presented. The LMS can describe the inequilibrium turbulence phenomena down to the viscous sublayer. The calculated fluid flow and turbulence fields for the channel flows are in better agreement with the direct numerical simulation (DNS) results than those obtained using a Reynolds stress turbulence model, and the calculated near-wall dissipation rates are in qualitatively correct agreement with the DNS results. The LMS also successfully predicts the rapidly varying phase-lead of the wall shearing stress that occurs in a narrow range of the dimensionless frequency omega (+) = (omega x nu)/(upsilon x tau(exp2)) for the pulsating pipe flows while various other turbulence models fail to predict this phenomenon, and the LMS yields significantly improved numerical results for a wide range of the dimensionless frequency compared with those obtained using a rapid distortion theory (RDT).

  10. Number Games, Magnitude Representation, and Basic Number Skills in Preschoolers

    ERIC Educational Resources Information Center

    Whyte, Jemma Catherine; Bull, Rebecca

    2008-01-01

    The effect of 3 intervention board games (linear number, linear color, and nonlinear number) on young children's (mean age = 3.8 years) counting abilities, number naming, magnitude comprehension, accuracy in number-to-position estimation tasks, and best-fit numerical magnitude representations was examined. Pre- and posttest performance was…

  11. Baryon-Plus Number Violation at High Temperatures for Arbitrary Higgs Mass

    NASA Astrophysics Data System (ADS)

    Li, Xu.

    In this thesis, baryon-plus-lepton (B + L) number violation in the electroweak theory of the Weinberg-Salam model is systematically studied. B + L number non-conservation in the electroweak theory is believed to be a consequence of the axial U(1) anomaly. It is argued that sphaleron, not instanton dominates the topological vacuum-to-vacuum transitions for B + L number change at high temperatures. The rate of change is reduced to a dimensionless prefactor kappa which is related to the determinants of small fluctuations around the sphaleron configuration. And kappa is exactly computed at high temperatures exploiting symmetries of sphaleron under spatial rotations combined with isospin and custodial SU(2) transformations. For the ratio lambda/g^2 of scalar four point coupling lambda to gauge coupling g^2 near unity, it is found that kappa is 0.03. and the rate of B + L number change at temperatures of order 1 Tev is about 8 to 9 orders of magnitude faster than the expansion rate of the big bang theory. For lambda/g ^2 large corresponding to a strongly coupled Higgs phase, or for lambda/g^2 very small tending to the Coleman-Weinberg limit, it is found that the determinant strongly suppresses the rate of baryon number changing processes.

  12. Parametric number covariance in quantum chaotic spectra.

    PubMed

    Vinayak; Kumar, Sandeep; Pandey, Akhilesh

    2016-03-01

    We study spectral parametric correlations in quantum chaotic systems and introduce the number covariance as a measure of such correlations. We derive analytic results for the classical random matrix ensembles using the binary correlation method and obtain compact expressions for the covariance. We illustrate the universality of this measure by presenting the spectral analysis of the quantum kicked rotors for the time-reversal invariant and time-reversal noninvariant cases. A local version of the parametric number variance introduced earlier is also investigated.

  13. The effect of Bond number on pool boiling for mini-fin surfaces and different working fluids

    NASA Astrophysics Data System (ADS)

    Strąk, Ewelina; Pastuszko, Robert

    2016-03-01

    Experimental nucleate pool boiling data were collected for structures in the form of extended surfaces sintered with perforated foil. The article describes experimental investigations for two kinds of surfaces: smooth and mini-fins with sintered perforated foil (MFP). The MFP surfaces were manufactured out of perforated copper foil (pore diameters: 0.05 - 0.3 mm) sintered with the mini-fins, uniformly spaced on the base surface. The experiments were carried out at atmospheric pressure for four kinds of the fluids: water, ethanol, FC-72 and Novec 649. The results for these working fluids were compared in terms of the Bond number and other dimensionless parameters. For all working fluids, the heat transfer coefficients obtained for the MFP surfaces were from 2 to 5 times higher than those for the smooth surface. Using a regression analysis with reference to selected physical properties and several characteristic dimensions, it was possible to develop a correlation for the Nusselt number.

  14. Stimulation of human T cells by an influenza A vector expressing a CTL epitope from the HER-2/neu protooncogene results in higher numbers of antigen-specific TCRhi cells than stimulation with peptide. Divergent roles of IL-2 and IL-15.

    PubMed

    Efferson, Clay L; Kawano, Kouichiro; Tsuda, Naotake; Palese, Peter; García-Sastre, Adolfo; Ioannides, Constantin G

    2005-01-01

    Development of cancer vaccines requires approaches to induce expansion and functional differentiation of tumor antigen-specific effector and memory cells. The later are particularly relevant for prevention of disease relapse. Efficient induction of memory cells is hindered by the lack of information about the relationship between TCR stimulation and the cytokines required for Ag-specific memory CD8+ cells and proliferation and survival. Since viruses are known to induce memory T cells, an attenuated influenza A/PR8/34 virus with a truncated nonstructural (NS1) gene was generated containing the HER-2 CTL E75 epitope in its neuraminidase protein (KIF-NS virus). Stimulation of PBMC from healthy donors and of tumor-associated lymphocytes (TAL) from ovarian cancer patients with dendritic cells (DC) infected with KIF-NS (KIF-NS-DC), induced higher numbers of immediate memory effector CD8+ CD44hi CD122hi cells, expressing TCR specific for E75 (E75-TCR) than stimulation with peptide E75. Survival of CD44hi CD122hi cells was dependent on the levels of TCR; cells expressing lower levels of E75-TCR (MFI: 10(2)-10(3)) survived better in IL-2 while cells expressing high levels of TCR (MFI: 10(3)-10(4)) survived better in IL-15. This is the first report demonstrating induction of human Ag-specific memory CD8+ cells against a human tumor-antigen using a live attenuated recombinant influenza virus vector. Such vectors may provide a novel approach for preventive immunity in human cancer vaccine development.

  15. Enumeration of plane partitions with a restricted number of parts

    NASA Astrophysics Data System (ADS)

    Rovenchak, A. A.

    2014-11-01

    We use the quantum statistical approach to estimate the number of restricted plane partitions of an integer n with the number of parts not exceeding some finite N. We use the analogy between this number theory problem and the enumeration of microstates of the ideal two-dimensional Bose gas. The numbers of restricted plane partitions calculated with the conjectured expression agree well with the exact values for n from 10 to 20.

  16. 15. Stress Sheet, Truss number 2, span number 6, Superior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Stress Sheet, Truss number 2, span number 6, Superior Avenue viaduct. Drawing courtesy Engineering Dept., City of Cleveland. - Superior Avenue Viaduct, Cleveland East & West side, Cuyahoga Valley Vicinity, Cleveland, Cuyahoga County, OH

  17. Comparing two devices of suspended treadmill walking by varying body unloading and Froude number.

    PubMed

    Ruckstuhl, Heidi; Kho, Jenniefer; Weed, Matthew; Wilkinson, Miles W; Hargens, Alan R

    2009-11-01

    In rehabilitation, treadmill walking with body weight support is commonly used to reduce loads on lower extremities. (1) However, gait pattern alterations during unloading at constant Froude number are infrequently reported. (2) Furthermore, differences between two common devices for unloading are not well known. Therefore, we investigated two devices; a waist-high chamber with increased pressure called Lower Body Positive Pressure (LBPP), and a harness system (LiteGait), considered a standard system for unloading the lower body. Four gait parameters (cadence, normalized stride length, duty factor, and leg angle at touch down), heart rate, and comfort level were monitored in 12 healthy volunteers. Subjects walked at three body weight (BW) conditions (100%, 66%, and 33% BW) and three Froude numbers (Fr), which refer to a dimensionless speed reflecting slow walking (Fr=0.09), comfortable walking (Fr=0.25), and walk-run transition (Fr=0.5). Absolute treadmill speed was determined using Froude numbers reflecting dynamically similar motions during unloading. We found that (1) the normal gait pattern is altered during unloading at a constant Froude number. In rehabilitation, physical therapists should be aware that normal gait pattern may not need to be maintained during unloaded treadmill walking. (2) Gait parameters were not different when comparing LBPP to harness supported walking. However, heart rate was lower and comfort higher during unloaded LBPP ambulation compared to suspended harness walking. Therefore, suspended LBPP walking may be more appropriate for patients with cardiovascular disease and for conditions at high unloading. PMID:19674901

  18. Feeling Number: Grounding Number Sense in a Sense of Quantity

    ERIC Educational Resources Information Center

    Wagner, David; Davis, Brent

    2010-01-01

    Drawing on results from psychology and from cultural and linguistic studies, we argue for an increased focus on developing quantity sense in school mathematics. We explore the notion of "feeling number", a phrase that we offer in a twofold sense--resisting tendencies to feel numb-er (more numb) by developing a feeling for numbers and the…

  19. Natural Number Bias in Operations with Missing Numbers

    ERIC Educational Resources Information Center

    Christou, Konstantinos P.

    2015-01-01

    This study investigates the hypothesis that there is a natural number bias that influences how students understand the effects of arithmetical operations involving both Arabic numerals and numbers that are represented by symbols for missing numbers. It also investigates whether this bias correlates with other aspects of students' understanding of…

  20. Toddlers' Spontaneous Attention to Number and Verbal Number Quantification

    ERIC Educational Resources Information Center

    Li, Xia

    2009-01-01

    "S"pontaneous "a"ttention to "n"umber (SAN) is the tendency to notice the relatively abstract attribute of number despite the presence of other attributes. According to nativists, an innate concept of one to three directs young children's attention to these "intuitive numbers" in everyday situations--even before they acquire language. According to…

  1. New expressions to describe solution nonideal osmotic pressure, freezing point depression, and vapor pressure.

    PubMed

    Fullerton, G D; Zimmerman, R J; Cantu, C; Cameron, I L

    1992-12-01

    New empirical expressions for osmotic pressure, freezing point depression, and vapor pressure are proposed based on the concepts of volume occupancy and (or) hydration force. These expressions are in general inverse relationships in comparison to the standard ideal expressions for the same properties. The slopes of the new equations are determined by the molecular weight of the solute and known constants. The accuracy and precision of the molecular weights calculated from the slope are identical and approximately 1% for the experiments reported here. The nonideality of all three colligative expressions is described by a dimensionless constant called the solute-solvent interaction parameter I. The results on sucrose have the same I = 0.26 for all three solution properties. The nonideality parameter I increased from 0.26 on sucrose to 1.7 on hemoglobin to successfully describe the well-known nonideal response of macromolecules.

  2. A feeling for the numbers in biology

    PubMed Central

    Phillips, Rob; Milo, Ron

    2009-01-01

    Although the quantitative description of biological systems has been going on for centuries, recent advances in the measurement of phenomena ranging from metabolism to gene expression to signal transduction have resulted in a new emphasis on biological numeracy. This article describes the confluence of two different approaches to biological numbers. First, an impressive array of quantitative measurements make it possible to develop intuition about biological numbers ranging from how many gigatons of atmospheric carbon are fixed every year in the process of photosynthesis to the number of membrane transporters needed to provide sugars to rapidly dividing Escherichia coli cells. As a result of the vast array of such quantitative data, the BioNumbers web site has recently been developed as a repository for biology by the numbers. Second, a complementary and powerful tradition of numerical estimates familiar from the physical sciences and canonized in the so-called “Fermi problems” calls for efforts to estimate key biological quantities on the basis of a few foundational facts and simple ideas from physics and chemistry. In this article, we describe these two approaches and illustrate their synergism in several particularly appealing case studies. These case studies reveal the impact that an emphasis on numbers can have on important biological questions. PMID:20018695

  3. Time dependence of adiabatic particle number

    NASA Astrophysics Data System (ADS)

    Dabrowski, Robert; Dunne, Gerald V.

    2016-09-01

    We consider quantum field theoretic systems subject to a time-dependent perturbation, and discuss the question of defining a time-dependent particle number not just at asymptotic early and late times, but also during the perturbation. Naïvely, this is not a well-defined notion for such a nonequilibrium process, as the particle number at intermediate times depends on a basis choice of reference states with respect to which particles and antiparticles are defined, even though the final late-time particle number is independent of this basis choice. The basis choice is associated with a particular truncation of the adiabatic expansion. The adiabatic expansion is divergent, and we show that if this divergent expansion is truncated at its optimal order, a universal time dependence is obtained, confirming a general result of Dingle and Berry. This optimally truncated particle number provides a clear picture of quantum interference effects for perturbations with nontrivial temporal substructure. We illustrate these results using several equivalent definitions of adiabatic particle number: the Bogoliubov, Riccati, spectral function and Schrödinger picture approaches. In each approach, the particle number may be expressed in terms of the tiny deviations between the exact and adiabatic solutions of the Ermakov-Milne equation for the associated time-dependent oscillators.

  4. A Lesson in Number Pattern

    ERIC Educational Resources Information Center

    Fletcher, Rodney

    2008-01-01

    This article presents a guided investigation into the spacial relationships between the centres of the squares in a Fibonacci tiling. It is essentially a lesson in number pattern, but includes work with surds, coordinate geometry, and some elementary use of complex numbers. The investigation could be presented to students in a number of ways…

  5. Random Numbers and Quantum Computers

    ERIC Educational Resources Information Center

    McCartney, Mark; Glass, David

    2002-01-01

    The topic of random numbers is investigated in such a way as to illustrate links between mathematics, physics and computer science. First, the generation of random numbers by a classical computer using the linear congruential generator and logistic map is considered. It is noted that these procedures yield only pseudo-random numbers since…

  6. Linear or Exponential Number Lines

    ERIC Educational Resources Information Center

    Stafford, Pat

    2011-01-01

    Having decided to spend some time looking at one's understanding of numbers, the author was inspired by "Alex's Adventures in Numberland," by Alex Bellos to look at one's innate appreciation of number. Bellos quotes research studies suggesting that an individual's natural appreciation of numbers is more likely to be exponential rather than linear,…

  7. PLURIDICTA, Numbers 28-35.

    ERIC Educational Resources Information Center

    Wagner, Johannes, Ed.

    1998-01-01

    The eight titles in this document include the following: "Comprehension and Input Processing as Useful Terms in the Field of SLA" (number 28) (Teresa Cadierno); "On the Role of Instruction in SLA: Research Results and Theoretical Explanations" (number 29) (Teresa Cadierno); "Can Writing Be Taught" (number 30) (Stuart Greene); "Academic Listening"…

  8. Generalized Bernoulli-Hurwitz numbers and the universal Bernoulli numbers

    NASA Astrophysics Data System (ADS)

    Ônishi, Yoshihiro

    2011-10-01

    The three fundamental properties of the Bernoulli numbers, namely, the von Staudt-Clausen theorem, von Staudt's second theorem, and Kummer's original congruence, are generalized to new numbers that we call generalized Bernoulli-Hurwitz numbers. These are coefficients in the power series expansion of a higher-genus algebraic function with respect to a suitable variable. Our generalization differs strongly from previous works. Indeed, the order of the power of the modulus prime in our Kummer-type congruences is exactly the same as in the trigonometric function case (namely, Kummer's own congruence for the original Bernoulli numbers), and as in the elliptic function case (namely, H. Lang's extension for the Hurwitz numbers). However, in other past results on higher-genus algebraic functions, the modulus was at most half of its value in these classical cases. This contrast is clarified by investigating the analogue of the three properties above for the universal Bernoulli numbers. Bibliography: 34 titles.

  9. Perceiving numbers influences actions in number-space synesthesia.

    PubMed

    Arend, Isabel; Gertner, Limor; Henik, Avishai

    2013-01-01

    Number and space are spontaneously linked in human cognition and have been metaphorically described as a 'mental number line'. In number-space synesthetes (NSS), numbers are visualized in specific spatial arrays, in an idiosyncratic and explicit manner. Here we tested whether the numerical-spatial association that characterizes NSS has the potential to affect individual's actions when the number is not a task-relevant feature. We used a Simon task that implies stimulus-response matching. Task-irrelevant Arabic numerals (1, 4, 6, 9) appeared simultaneously at the same location as a colored target. A group of 15 age-matched controls and 4 NSS completed a 2×2 within-subjects design consisting of Simon (compatible and incompatible) and number-space (congruent and incongruent) trials. Mean reaction time (RT) and RT cumulative distribution functions across Simon and number-space conditions for both NSS and controls were analyzed. Relative to controls, synesthetes' RTs were overall affected by the number-space mapping. Moreover, synesthetes' Simon effects occurred at later response times. These results provide strong evidence that numbers are cognitively represented as action codes and that the strength of the association shapes the impact of the numerical representation on individuals' actions.

  10. What exactly do numbers mean?

    PubMed Central

    Huang, Yi Ting; Spelke, Elizabeth; Snedeker, Jesse

    2014-01-01

    Number words are generally used to refer to the exact cardinal value of a set, but cognitive scientists disagree about their meanings. Although most psychological analyses presuppose that numbers have exact semantics (two means EXACTLY TWO), many linguistic accounts propose that numbers have lower-bounded semantics (AT LEAST TWO), and that speakers restrict their reference through a pragmatic inference (scalar implicature). We address this debate through studies of children who are in the process of acquiring the meanings of numbers. Adults and 2- and 3-year-olds were tested in a novel paradigm that teases apart semantic and pragmatic aspects of interpretation (the covered box task). Our findings establish that when scalar implicatures are cancelled in the critical trials of this task, both adults and children consistently give exact interpretations for number words. These results, in concert with recent work on real-time processing, provide the first unambiguous evidence that number words have exact semantics. PMID:25285053

  11. Familial Sinistrals Avoid Exact Numbers

    PubMed Central

    Sauerland, Uli; Gotzner, Nicole

    2013-01-01

    We report data from an internet questionnaire of sixty number trivia. Participants were asked for the number of cups in their house, the number of cities they know and 58 other quantities. We compare the answers of familial sinistrals – individuals who are left-handed themselves or have a left-handed close blood-relative – with those of pure familial dextrals – right-handed individuals who reported only having right-handed close blood-relatives. We show that familial sinistrals use rounder numbers than pure familial dextrals in the survey responses. Round numbers in the decimal system are those that are multiples of powers of 10 or of half or a quarter of a power of 10. Roundness is a gradient concept, e.g. 100 is rounder than 50 or 200. We show that very round number like 100 and 1000 are used with 25% greater likelihood by familial sinistrals than by pure familial dextrals, while pure familial dextrals are more likely to use less round numbers such as 25, 60, and 200. We then use Sigurd’s (1988, Language in Society) index of the roundness of a number and report that familial sinistrals’ responses are significantly rounder on average than those of pure familial dextrals. To explain the difference, we propose that the cognitive effort of using exact numbers is greater for the familial sinistral group because their language and number systems tend to be more distributed over both hemispheres of the brain. Our data support the view that exact and approximate quantities are processed by two separate cognitive systems. Specifically, our behavioral data corroborates the view that the evolutionarily older, approximate number system is present in both hemispheres of the brain, while the exact number system tends to be localized in only one hemisphere. PMID:23544052

  12. Familial sinistrals avoid exact numbers.

    PubMed

    Sauerland, Uli; Gotzner, Nicole

    2013-01-01

    We report data from an internet questionnaire of sixty number trivia. Participants were asked for the number of cups in their house, the number of cities they know and 58 other quantities. We compare the answers of familial sinistrals--individuals who are left-handed themselves or have a left-handed close blood-relative--with those of pure familial dextrals--right-handed individuals who reported only having right-handed close blood-relatives. We show that familial sinistrals use rounder numbers than pure familial dextrals in the survey responses. Round numbers in the decimal system are those that are multiples of powers of 10 or of half or a quarter of a power of 10. Roundness is a gradient concept, e.g. 100 is rounder than 50 or 200. We show that very round number like 100 and 1000 are used with 25% greater likelihood by familial sinistrals than by pure familial dextrals, while pure familial dextrals are more likely to use less round numbers such as 25, 60, and 200. We then use Sigurd's (1988, Language in Society) index of the roundness of a number and report that familial sinistrals' responses are significantly rounder on average than those of pure familial dextrals. To explain the difference, we propose that the cognitive effort of using exact numbers is greater for the familial sinistral group because their language and number systems tend to be more distributed over both hemispheres of the brain. Our data support the view that exact and approximate quantities are processed by two separate cognitive systems. Specifically, our behavioral data corroborates the view that the evolutionarily older, approximate number system is present in both hemispheres of the brain, while the exact number system tends to be localized in only one hemisphere.

  13. Number development and developmental dyscalculia.

    PubMed

    von Aster, Michael G; Shalev, Ruth S

    2007-11-01

    There is a growing consensus that the neuropsychological underpinnings of developmental dyscalculia (DD) are a genetically determined disorder of 'number sense', a term denoting the ability to represent and manipulate numerical magnitude nonverbally on an internal number line. However, this spatially-oriented number line develops during elementary school and requires additional cognitive components including working memory and number symbolization (language). Thus, there may be children with familial-genetic DD with deficits limited to number sense and others with DD and comorbidities such as language delay, dyslexia, or attention-deficit-hyperactivity disorder. This duality is supported by epidemiological data indicating that two-thirds of children with DD have comorbid conditions while one-third have pure DD. Clinically, they differ according to their profile of arithmetic difficulties. fMRI studies indicate that parietal areas (important for number functions), and frontal regions (dominant for executive working memory and attention functions), are under-activated in children with DD. A four-step developmental model that allows prediction of different pathways for DD is presented. The core-system representation of numerical magnitude (cardinality; step 1) provides the meaning of 'number', a precondition to acquiring linguistic (step 2), and Arabic (step 3) number symbols, while a growing working memory enables neuroplastic development of an expanding mental number line during school years (step 4). Therapeutic and educational interventions can be drawn from this model. PMID:17979867

  14. Compendium of Experimental Cetane Numbers

    SciTech Connect

    Yanowitz, J.; Ratcliff, M. A.; McCormick, R. L.; Taylor, J. D.; Murphy, M. J.

    2014-08-01

    This report is an updated version of the 2004 Compendium of Experimental Cetane Number Data and presents a compilation of measured cetane numbers for pure chemical compounds. It includes all available single compound cetane number data found in the scientific literature up until March 2014 as well as a number of unpublished values, most measured over the past decade at the National Renewable Energy Laboratory. This Compendium contains cetane values for 389 pure compounds, including 189 hydrocarbons and 201 oxygenates. More than 250 individual measurements are new to this version of the Compendium. For many compounds, numerous measurements are included, often collected by different researchers using different methods. Cetane number is a relative ranking of a fuel's autoignition characteristics for use in compression ignition engines; it is based on the amount of time between fuel injection and ignition, also known as ignition delay. The cetane number is typically measured either in a single-cylinder engine or a constant volume combustion chamber. Values in the previous Compendium derived from octane numbers have been removed, and replaced with a brief analysis of the correlation between cetane numbers and octane numbers. The discussion on the accuracy and precision of the most commonly used methods for measuring cetane has been expanded and the data has been annotated extensively to provide additional information that will help the reader judge the relative reliability of individual results.

  15. A Laboratory Experiment on How to Create Dimensionless Correlations

    ERIC Educational Resources Information Center

    Edwards, Robert V.

    2010-01-01

    An experiment is described that illustrates how chemical engineering correlations are created. Balls of different diameters and different specific gravities (all less than one) are dropped from several heights into a pool of water, and the maximum depth reached by the ball is measured. This data is used to estimate the coefficients for a…

  16. Rayleigh Number for Core Convection: Three Independent Estimates

    NASA Astrophysics Data System (ADS)

    Gubbins, D.

    2002-12-01

    The Rayleigh number (Ra) for the Earth's core is a dimensionless measure of the heat flux crossing the core-mantle boundary (CMB). Recent calculations on the properties of liquid iron mixtures at core pressures and temperatures have provided reliable data for thermodynamic estimates of core heat flow, all of which suggests that heat budget is rather tight: Either the core is cooling so fast that the inner core is young and formed only 1~Gyr ago, or the core contains substantial radiogenic heating from K40. These heat flow estimates translate into Ra≈ 1000Rac, the critical value for convection assuming a magnetic field of typical core strength and turbulent values of viscosity and thermal diffusivity [Gubbins, Phys. Earth Planet. Int., 128 3--12, 2001]. Magnetic fields facilitate convection in a rotating system; for core parameters they lower Rac by a factor of about 1000. The estimate of Ra is therefore close to the marginal value, the minimum heat flux needed for convection in the core if the magnetic field were absent. Another estimate was made by Jones [Phil. Trans. R. Soc. Lond., 358 871--872, 2000] by considering the heat transported by convection in the core. This gives a similar value of 500Rac; it is independent because the basic information used is a typical estimate of core flow speed rather than CMB heat flux. The third estimate comes from the observation of low secular variation in the Pacific. Seismic tomography shows low velocity, probably hot material, at the base of the mantle in the Pacific region. Using this as a boundary condition for simple convection calculations shows that the usual Busse rolls are completely suppressed in the Pacific when lateral variations are 30%\\ of the mean heat flux and total heat flux is just above critical. While much work needs to be done on extending these simple calculations, they imply that the heat flux from the Pacific region is subadiabatic. Converting the variations of seismic velocity within D'' to heat

  17. Counting copy number and calories.

    PubMed

    White, Stefan

    2015-08-01

    Copy number variation (CNV) at several genomic loci has been associated with different human traits and diseases, but in many cases the findings could not be replicated. A new study provides insights into the degree of variation present at the amylase locus and calls into question a previous association between amylase copy number and body mass index. PMID:26220133

  18. Toddlers' Spontaneous Attention to Number

    ERIC Educational Resources Information Center

    Baroody, Arthur J.; Li, Xia; Lai, Meng-lung

    2008-01-01

    Hannula and Lehtinen (2001, 2005) defined spontaneous focusing on numerosity (SFON) as the tendency to notice the relatively abstract attribute of number despite the presence of other attributes. According to nativists, an innate concept of one to three directs young children's attention to these "intuitive numbers" in everyday situations--even…

  19. Spontaneous Number Representation in Mosquitofish

    ERIC Educational Resources Information Center

    Dadda, Marco; Piffer, Laura; Agrillo, Christian; Bisazza, Angelo

    2009-01-01

    While there is convincing evidence that preverbal human infants and non-human primates can spontaneously represent number, considerable debate surrounds the possibility that such capacity is also present in other animals. Fish show a remarkable ability to discriminate between different numbers of social companions. Previous work has demonstrated…

  20. Acceptance of Others (Number Form).

    ERIC Educational Resources Information Center

    Masters, James R.; Laverty, Grace E.

    As part of the instrumentation to assess the effectiveness of the Schools Without Failure (SWF) program in 10 elementary schools in the New Castle, Pa. School District, the Acceptance of Others (Number Form) was prepared to determine pupil's attitudes toward classmates. Given a list of all class members, pupils are asked to circle a number from 1…

  1. Regular Numbers and Mathematical Worlds

    ERIC Educational Resources Information Center

    Whitacre, Ian; Bouhjar, Khalid; Bishop, Jessica Pierson; Philipp, Randolph; Schappelle, Bonnie P.

    2016-01-01

    Rather than describing the challenges of integer learning in terms of a transition from positive to negative numbers, we have arrived at a different perspective: We view students as inhabiting distinct mathematical worlds consisting of particular types of numbers (as construed by the students). These worlds distinguish and illuminate students'…

  2. Pseudo-Random Number Generators

    NASA Technical Reports Server (NTRS)

    Howell, L. W.; Rheinfurth, M. H.

    1984-01-01

    Package features comprehensive selection of probabilistic distributions. Monte Carlo simulations resorted to whenever systems studied not amenable to deterministic analyses or when direct experimentation not feasible. Random numbers having certain specified distribution characteristic integral part of simulations. Package consists of collector of "pseudorandom" number generators for use in Monte Carlo simulations.

  3. Organizing, Concerns and Control Numbers.

    ERIC Educational Resources Information Center

    Washington, Gene

    A heuristic procedure can be used to teach organizational skills to students of technical writing. Designed to allow students on their own to explore ways that numbers can be used to give a definite shape to technical information, its central feature is a matrix composed of a series of control numbers (horizontal axis) and organizing concerns…

  4. Building Buildings with Triangular Numbers

    ERIC Educational Resources Information Center

    Pagni, David L.

    2006-01-01

    Triangular numbers are used to unravel a new sequence of natural numbers here-to-fore not appearing on the Encyclopedia of Integer Sequences website. Insight is provided on the construction of the sequence using "buildings" as a viewable model of the sequence entries. A step-by-step analysis of the sequence pattern reveals a method for generating…

  5. On Counting the Rational Numbers

    ERIC Educational Resources Information Center

    Almada, Carlos

    2010-01-01

    In this study, we show how to construct a function from the set N of natural numbers that explicitly counts the set Q[superscript +] of all positive rational numbers using a very intuitive approach. The function has the appeal of Cantor's function and it has the advantage that any high school student can understand the main idea at a glance…

  6. Investigating the Randomness of Numbers

    ERIC Educational Resources Information Center

    Pendleton, Kenn L.

    2009-01-01

    The use of random numbers is pervasive in today's world. Random numbers have practical applications in such far-flung arenas as computer simulations, cryptography, gambling, the legal system, statistical sampling, and even the war on terrorism. Evaluating the randomness of extremely large samples is a complex, intricate process. However, the…

  7. Old and New Magic Numbers

    SciTech Connect

    Talmi, Igal

    2008-11-11

    The discovery of magic numbers led to the shell model. They indicated closure of major shells and are robust: proton magic numbers are rather independent of the occupation of neutron orbits and vice versa. Recently the magic property became less stringent and we hear a lot about the discovery of new magic numbers. These, however, indicate sub-shell closures and strongly depend on occupation numbers and hence, may be called quasi-magic numbers. Some of these have been known for many years and the mechanism for their appearance as well as disappearance, was well understood within the simple shell model. The situation will be illustrated by a few examples which demonstrate the simple features of the shell model. Will this simplicity emerge from the complex computations of nuclear many-body theory?.

  8. Number without a language model.

    PubMed

    Spaepen, Elizabet; Coppola, Marie; Spelke, Elizabeth S; Carey, Susan E; Goldin-Meadow, Susan

    2011-02-22

    Cross-cultural studies suggest that access to a conventional language containing words that can be used for counting is essential to develop representations of large exact numbers. However, cultures that lack a conventional counting system typically differ from cultures that have such systems, not only in language but also in many other ways. As a result, it is difficult to isolate the effects of language on the development of number representations. Here we examine the numerical abilities of individuals who lack conventional language for number (deaf individuals who do not have access to a usable model for language, spoken or signed) but who live in a numerate culture (Nicaragua) and thus have access to other aspects of culture that might foster the development of number. These deaf individuals develop their own gestures, called homesigns, to communicate. We show that homesigners use gestures to communicate about number. However, they do not consistently extend the correct number of fingers when communicating about sets greater than three, nor do they always correctly match the number of items in one set to a target set when that target set is greater than three. Thus, even when integrated into a numerate society, individuals who lack input from a conventional language do not spontaneously develop representations of large exact numerosities.

  9. Who's Expressing in "Expressive Writing"?

    ERIC Educational Resources Information Center

    Reed, Janine

    In an attempt to understand what expressive writing means to themselves and to their students, teachers should explore and reflect on various questions regarding expressive writing theories and practices. For many, self-expression is the basis of all serious writing and an important stage in any act of learning, so it is essential to uncover the…

  10. Reynolds number influences in aeronautics

    NASA Technical Reports Server (NTRS)

    Bushnell, Dennis M.; Yip, Long P.; Yao, Chung-Sheng; Lin, John C.; Lawing, Pierce L.; Batina, John T.; Hardin, Jay C.; Horvath, Thomas J.; Fenbert, James W.; Domack, Christopher S.

    1993-01-01

    Reynolds number, a measure of the ratio of inertia to viscous forces, is a fundamental similarity parameter for fluid flows and therefore, would be expected to have a major influence in aerodynamics and aeronautics. Reynolds number influences are generally large, but monatomic, for attached laminar (continuum) flow; however, laminar flows are easily separated, inducing even stronger, non-monatomic, Reynolds number sensitivities. Probably the strongest Reynolds number influences occur in connection with transitional flow behavior. Transition can take place over a tremendous Reynolds number range, from the order of 20 x 10(exp 3) for 2-D free shear layers up to the order of 100 x 10(exp 6) for hypersonic boundary layers. This variability in transition behavior is especially important for complex configurations where various vehicle and flow field elements can undergo transition at various Reynolds numbers, causing often surprising changes in aerodynamics characteristics over wide ranges in Reynolds number. This is further compounded by the vast parameterization associated with transition, in that any parameter which influences mean viscous flow development (e.g., pressure gradient, flow curvature, wall temperature, Mach number, sweep, roughness, flow chemistry, shock interactions, etc.), and incident disturbance fields (acoustics, vorticity, particulates, temperature spottiness, even electro static discharges) can alter transition locations to first order. The usual method of dealing with the transition problem is to trip the flow in the generally lower Reynolds number wind tunnel to simulate the flight turbulent behavior. However, this is not wholly satisfactory as it results in incorrectly scaled viscous region thicknesses and cannot be utilized at all for applications such as turbine blades and helicopter rotors, nacelles, leading edge and nose regions, and High Altitude Long Endurance and hypersonic airbreathers where the transitional flow is an innately critical

  11. On the drag of model dendrite fragments at low Reynolds number

    NASA Technical Reports Server (NTRS)

    Zakhem, R.; Weidman, P. D.; De Groh, H. C., III

    1992-01-01

    An experimental study of low Reynolds number drag on laboratory models of dendrite fragments has been conducted. The terminal velocities of the dendrites undergoing free fall along their axis of symmetry were measured in a large Stokes flow facility. Corrections for wall interference give nearly linear drag vs Reynolds number curves. Corrections for both wall interference and inertia effects show that the dendrite Stokes settling velocities are always less than that of a sphere of equal mass and volume. In the Stokes limit, the settling speed ratio is found to correlate well with the primary dendrite arm aspect ratio and a second dimensionless shape parameter which serves as a measure of the fractal-like nature of the dendrite models. These results can be used to estimate equiaxed grain velocities and distance of travel in metal castings. The drag measurements may be used in numerical codes to calculate the movement of grains in a convecting melt in an effort to determine macrosegregation patterns caused by the sink/float mechanism.

  12. On the drag of model dendrite fragments at low Reynolds number

    NASA Technical Reports Server (NTRS)

    Zakhem, R.; Weidman, P. D.; Degroh, H. C., III

    1993-01-01

    An experimental study of low Reynolds number drag on laboratory models of dendrite fragments has been conducted. The terminal velocities of the dendrites undergoing free fall along their axis of symmetry were measured in a large Stokes flow facility. Corrections for wall interference give nearly linear drag vs Reynolds number curves. Corrections for both wall interference and inertia effects show that the dendrite Stokes settling velocities are always less than that of a sphere of equal mass and volume. In the Stokes limit, the settling speed ratio is found to correlate well with primary dendrite arm aspect ratio and a second dimensionless shape paremeter which serves as a measure of the fractal-like nature of the dendrite models. These results can be used to estimate equiaxed grain velocities and distance of travel in metal castings. The drag measurements may be used in numerical codes to calculate the movement of grains in a convecting melt in an effort to determine macrosegregation patterns caused by the sink/float mechanism.

  13. Drag force on a spherical intruder in a granular bed at low Froude number.

    PubMed

    Hilton, J E; Tordesillas, A

    2013-12-01

    The drag force on an object, or "intruder," in a granular material arises from interparticle friction, as well as the cyclic creation and buckling of force chains within the material. In contrast to fluids, for which drag forces are well understood, there is no straightforward relationship between speed and mean drag force in granular materials. We investigate spherical intruder particles of varying radii moving at low speeds through granular beds. The system can be parametrized using the dimensionless Froude number Fr=2v/√[gR], for intruders of radius R moving at a speed v. For frictional systems, we find the drag force obeys a linear relationship with Fr for low Froude numbers above Fr>1. For Fr<1 we observe a deviation from this linear trend. This transition can be explained by considering the characteristic inertial and gravitational granular time scales of the system. We show that a suitably normalized measure of dissipated power obeys a linear relationship with the imposed intruder velocity, independent of the intruder dimensions. This is found to hold even for particles with no friction, identifying a relationship between the imposed motion of the intruder and the resistance of the granular material to purely geometric rearrangements.

  14. Numbered nasal discs for waterfowl

    USGS Publications Warehouse

    Bartonek, J.C.; Dane, C.W.

    1964-01-01

    Numbered nasal discs were successfully used in studies requiring large numbers of individually marked waterfowl. The procedure for constructing these discs is outlined. Blue-winged teal (Anas discors) with 5/8-inch discs, and canvasback (Aythya valisineria) and redhead (A. americana) with 3/4-inch discs can be individually identified up to 50 and 80 yards, respectively, with a gunstock-mounted, 20-power spotting scope. The particular value of these markers is their durability, the number of combinations possible, and the apparent absence of behavioral or mortality influence among such species as the blue-winged teal.

  15. Pinning of fermionic occupation numbers.

    PubMed

    Schilling, Christian; Gross, David; Christandl, Matthias

    2013-01-25

    The Pauli exclusion principle is a constraint on the natural occupation numbers of fermionic states. It has been suspected since at least the 1970s, and only proved very recently, that there is a multitude of further constraints on these numbers, generalizing the Pauli principle. Here, we provide the first analytic analysis of the physical relevance of these constraints. We compute the natural occupation numbers for the ground states of a family of interacting fermions in a harmonic potential. Intriguingly, we find that the occupation numbers are almost, but not exactly, pinned to the boundary of the allowed region (quasipinned). The result suggests that the physics behind the phenomenon is richer than previously appreciated. In particular, it shows that for some models, the generalized Pauli constraints play a role for the ground state, even though they do not limit the ground-state energy. Our findings suggest a generalization of the Hartree-Fock approximation.

  16. Integral Presentations of Catalan Numbers

    ERIC Educational Resources Information Center

    Dana-Picard, Thierry

    2010-01-01

    We compute in three different ways the same definite parametric integral. By-products are the derivation of a combinatorial identity and two integral presentations of Catalan numbers. One of them leads to a presentation using the [gamma] function.

  17. Fibonacci Numbers and the Spreadsheet.

    ERIC Educational Resources Information Center

    Verderber, Nadine L.

    1991-01-01

    Described is a classroom activity incorporating a computer spreadsheet to study number patterns generated by the Fibonacci sequence. Included are examples and suggestions for the use of the spreadsheet in other recursive relationships. (JJK)

  18. Poison control center - emergency number

    MedlinePlus

    For a POISON EMERGENCY call: 1-800-222-1222 ANYWHERE IN THE UNITED STATES This national hotline number will let you ... is a free and confidential service. All local poison control centers in the United States use this ...

  19. Atomic Structure - A Numbers Game

    ERIC Educational Resources Information Center

    George, W. O.; Vincent, A.

    1975-01-01

    Emphasizes the simplicity and elegance of early discoveries related to the hydrogen spectrum and provides an elementary experimental basis of quantum theory based on a "numbers game" which can be played by students. (Author/GS)

  20. Flagella number among Naegleria flagellates.

    PubMed

    John, D T; Cole, T B; John, R A

    1991-01-01

    Scanning electron microscopy was used to determine the number of flagella on the flagellates of Naegleria australiensis, N. fowleri, N. gruberi, and N. jadini. Although the majority of flagellates had 2 flagella, there was considerable variation among individual cells. The number of flagella per flagellate varied from 1-8, with 2.4 being the average number per cell. For the different species, the average number of flagella per cell ranged from 2.0 in N. jadini to 3.1 for N. australiensis. The greatest amount of variation occurred in N. australiensis, with only 43% of the cells having 2 flagella. By contrast, 92% of N. fowleri cells had 2 flagella. Naegleria jadini and N. gruberi were intermediate with 80% and 74% biflagellates, respectively.

  1. Random numbers from vacuum fluctuations

    NASA Astrophysics Data System (ADS)

    Shi, Yicheng; Chng, Brenda; Kurtsiefer, Christian

    2016-07-01

    We implement a quantum random number generator based on a balanced homodyne measurement of vacuum fluctuations of the electromagnetic field. The digitized signal is directly processed with a fast randomness extraction scheme based on a linear feedback shift register. The random bit stream is continuously read in a computer at a rate of about 480 Mbit/s and passes an extended test suite for random numbers.

  2. Quantum Adder of Classical Numbers

    NASA Astrophysics Data System (ADS)

    Cherkas, A. V.; Chivilikhin, S. A.

    2016-08-01

    In this article we show the precise algorithm of functioning of quantum adder on the example of addition of two 2-bit numbers. It consists of the quantum Fourier transformer and conditional rotation gates that let us use the minimum number of qubits to get the addition realization of the sum. Despite the fact that the algorithm uses the minimum amount of operations this accelerates the process of the adder.

  3. Graspable Objects Shape Number Processing

    PubMed Central

    Ranzini, Mariagrazia; Lugli, Luisa; Anelli, Filomena; Carbone, Rossella; Nicoletti, Roberto; Borghi, Anna M.

    2011-01-01

    The field of numerical cognition represents an interesting case for action-based theories of cognition, since number is a special kind of abstract concept. Several studies have shown that within the parietal lobes adjacent neural regions code numerical magnitude and grasping-related information. This anatomical proximity between brain areas involved in number and sensorimotor processes may account for interactions between numerical magnitude and action. In particular, recent studies have demonstrated a causal role of action perception on numerical magnitude processing. If objects are represented in terms of actions (affordances), the causal role of action on number processing should extend to the case of objects affordances. This study investigates the relationship between numbers and objects affordances in two experiments, without (Experiment 1) or with (Experiment 2) the requirement of an action (i.e., participants were asked to hold an object in their hands during the task). The task consisted in repeating aloud the odd or even digit within a pair depending on the type of the preceding or following object. Order of presentation (object–number vs. number–object), Object type (graspable vs. ungraspable), Object size (small vs. large), and Numerical magnitude (small vs. large) were manipulated for each experiment. Experiment 1 showed a facilitation – in terms of quicker responses – for graspable over ungraspable objects preceded by numbers, and an effect of numerical magnitude after the presentation of graspable objects. Experiment 2 demonstrated that the action execution enhanced overall the sensitivity to numerical magnitude, and that at the same time it interfered with the effects of objects affordances on number processing. Overall, these findings demonstrate that numbers and graspable objects are strongly interrelated, supporting the view that abstract concepts may be grounded in the motor experience. PMID:22164141

  4. Copy number variation and mutation

    NASA Astrophysics Data System (ADS)

    Clark, Brian; Weidner, Jacob; Wabick, Kevin

    2009-11-01

    Until very recently, the standard model of DNA included two genes for each trait. This dated model has given way to a model that includes copies of some genes well in excess of the canonical two. Copy number variations in the human genome play critical roles in causing or aggravating a number of syndromes and diseases while providing increased resistance to others. We explore the role of mutation, crossover, inversion, and reproduction in determining copy number variations in a numerical simulation of a population. The numerical model consists of a population of individuals, where each individual is represented by a single strand of DNA with the same number of genes. Each gene is initially assigned to one of two traits. Fitness of the individual is determined by the two most fit genes for trait one, and trait two genetic material is treated as a reservoir of junk DNA. After a sufficient number of generations, during which the genetic distribution is allowed to reach a steady-state, the mean numberof genes per trait and the copy number variation are recorded. Here, we focus on the role of mutation and compare simulation results to theory.

  5. Project Solo; Newsletter Number Twelve.

    ERIC Educational Resources Information Center

    Pittsburgh Univ., PA. Project Solo.

    Several student-authored computer programs are presented which do advanced plot routines. They are remarkable in that they are able to plot a function expressed in polar coordinates on a teletype. Some plot routines developed by the Project Solo staff are also presented. They are designed to be used with a Hewlett Packard 7200 A plotter connected…

  6. Pluridicta, Numbers 1-27.

    ERIC Educational Resources Information Center

    Pluridicta, 1993

    1993-01-01

    The following titles are included: (1) "Computer in Foreign Language Instruction"; (2) "Two Sides of the Same Coin: Prose and Poetry in Translation"; (3) "Notions of Culture in Foreign Language Departments in Different Countries"; (4) "Developing Materials for Teaching Danish to Adult Immigrants"; (5) "Conversational Strategies in Expressive,…

  7. Symbiotic Expressions

    NASA Astrophysics Data System (ADS)

    Bernecky, Robert; Herhut, Stephan; Scholz, Sven-Bodo

    We introduce symbiotic expressions, a method for algebraic simplification within a compiler, in lieu of an SMT solver, such as Yices or the Omega Calculator. Symbiotic expressions are compiler-generated expressions, temporarily injected into a program's abstract syntax tree (AST). The compiler's normal optimizations interpret and simplify those expressions, making their results available for the compiler to use as a basis for decisions about further optimization of the source program. The expressions are symbiotic, in the sense that both parties benefit: an optimization benefits, by using the compiler itself to simplify expressions that have been attached, lamprey-like, to the AST by the optimization; the program being compiled benefits, from improved run-time in both serial and parallel environments.

  8. Unsteady force measurements in sphere flow from subcritical to supercritical Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Norman, A. K.; McKeon, B. J.

    2011-11-01

    The flow over a smooth sphere is examined in the Reynolds number range of 5.0 × 104 < Re < 5.0 × 105 via measurements of the fluctuating forces and particle image velocimetry measurements in a planar cut of the velocity field. Comprehensive studies of the statistics and spectra of the forces are presented for a range of subcritical and supercritical Reynolds numbers. While the subcritical lateral force spectra are dominated by activity corresponding to the large-scale vortex shedding frequency at a Strouhal number of approximately 0.18, there is no such peak apparent in the supercritical spectra, although resolution effects may become important in this region. Nor does the large-scale vortex shedding appear to have a significant effect on the drag force fluctuations at either sub- or super-critical Reynolds numbers. A simple double spring model is shown to capture the main features of the lateral force spectra. The low-frequency force fluctuations observed in earlier computational studies are shown to have important implications for statistical convergence, and in particular, the apparent mean side force observed in earlier studies. At least one thousand dimensionless time units are required for reasonable estimates of the second and higher moments below the critical Reynolds number and even more for supercritical flow, stringent conditions for computational studies. Lastly, investigation of the relationship between the motion of the instantaneous wake shape, defined via the local position where the streamwise velocity is equal to half the freestream value, and the in-plane lateral force for subcritical flow reveals a significant negative correlation throughout the near wake, which is shown to be related to a structure inferred to arise from the large-scale vortex shedding convecting downstream at 61% of the freestream velocity. In addition to its utility in understanding basic sphere flow, the apparatus is also a testbed that will be used in future studies

  9. 1987 CRC (Coordinating Research Council) octane number requirement survey

    SciTech Connect

    Not Available

    1988-08-01

    In the forty-first annual statistical survey of current model vehicles conducted by the Coordinating Research Council, Inc., test data were obtained on 389 1987 model vehicles, including 300 passenger cars and 89 light-duty trucks and vans. Eighteen laboratories participated in this Survey. Maximum octane number requirements were determined by testing at maximum-throttle conditions, as well as at part-throttle. Requirements are expressed as the (R+M)/2 octane number, Research octane number, and Motor octane number of the reference-fuel producing knock which was recurrent and repeatable at the lowest audible level. The primary analyses used in this report are based upon (R+M)/2 octane number requirements, rather than upon Research octane number requirements as in Survey reports prior to 1985. Estimated octane number requirements for the total vehicles are weighted in proportion to the 1987 vehicle model production and/or sales figures.

  10. CRC (Coordinating Research Council) octane number requirement survey

    SciTech Connect

    Not Available

    1986-10-01

    In the thirty-ninth annual statistical survey of current-model vehicles conducted by the Coordinating Research Council, Inc., test data were obtained on 374 1985 model vehicles, including 309 US vehicles and 65 imported vehicles. Fifteen laboratories participated in this Survey. Maximum octane number requirements were determined by testing under part-throttle conditions, as well as at maximum-throttle. Requirements are expressed as the (R+M)/2 octane number, Research octane number, and Motor octane number of the reference fuel producing knock which was recurrent and repeatable at the lowest audible level. The primary analyses used in this report are based upon (R+M)/2 octane number requirements, rather than upon Research octane number requirements as in previous reports. Estimated octane number requirements for the US vehicles are weighted in proportion to the 1985 vehicle model production figures and, for the imported models, in proportion to import sales volume in the United States.

  11. CRC (Coordinating Research Council) octane number requirement survey, 1986

    SciTech Connect

    Not Available

    1987-08-01

    In the fortieth annual statistical survey of current model vehicles conducted by the Coordinating Research Council, Inc., test data were obtained on 377 1986 model vehicles, including 314 US vehicles and 63 imported vehicles. Sixteen laboratories participated in this survey. Maximum octane number requirements were determined by testing at maximum-throttle conditions, as well as a part-throttle. Requirements are expressed as the (R+M)/2 octane number, Research octane number, and motor octane number of the reference fuel producing knock which was recurrent and repeatable at the lowest audible level. The primary analyses used in this report are based upon (R+M)/2 octane number requirements, rather than upon Research octane number requirements as in the survey reports prior to 1985. Estimated octane-number requirements for the US vehicles are weighted in proportion to the 1986 vehicle model production figures and, for the imported models, in proportion to import sales volume in the United States.

  12. Number Meaning and Number Grammar in English and Spanish

    ERIC Educational Resources Information Center

    Bock, Kathryn; Carreiras, Manuel; Meseguer, Enrique

    2012-01-01

    Grammatical agreement makes different demands on speakers of different languages. Being widespread in the languages of the world, the features of agreement systems offer valuable tests of how language affects deep-seated domains of human cognition and categorization. Number agreement is one such domain, with intriguing evidence that typological…

  13. Are Number Gestures Easier than Number Words for Preschoolers?

    ERIC Educational Resources Information Center

    Nicoladis, Elena; Pika, Simone; Marentette, Paula

    2010-01-01

    Some researchers have argued that children's earliest symbols are based on their sensorimotor experience and that arbitrary symbol-referent mapping poses a challenge for them. If so, exposure to iconic symbols (such as one-finger-for-one-object manual gestures) might help children in a difficult domain such as number. We assessed 44 preschoolers'…

  14. Transport numbers in transdermal iontophoresis.

    PubMed

    Mudry, Blaise; Guy, Richard H; Delgado-Charro, M Begoña

    2006-04-15

    Parameters determining ionic transport numbers in transdermal iontophoresis have been characterized. The transport number of an ion (its ability to carry charge) is key to its iontophoretic delivery or extraction across the skin. Using small inorganic ions, the roles of molar fraction and mobility of the co- and counterions present have been demonstrated. A direct, constant current was applied across mammalian skin in vitro. Cations were anodally delivered from either simple M(+)Cl(-) solutions (single-ion case, M(+) = sodium, lithium, ammonium, potassium), or binary and quaternary mixtures thereof. Transport numbers were deduced from ion fluxes. In the single-ion case, maximum cationic fluxes directly related to the corresponding ionic aqueous mobilities were found. Addition of co-ions decreased the transport numbers of all cations relative to the single-ion case, the degree of effect depending upon the molar fraction and mobility of the species involved. With chloride as the principal counterion competing to carry current across the skin (the in vivo situation), a maximum limit on the single or collective cation transport number was 0.6-0.8. Overall, these results demonstrate how current flowing across the skin during transdermal iontophoresis is distributed between competing ions, and establish simple rules with which to optimize transdermal iontophoretic transport.

  15. Stochastic low Reynolds number swimmers.

    PubMed

    Golestanian, Ramin; Ajdari, Armand

    2009-05-20

    As technological advances allow us to fabricate smaller autonomous self-propelled devices, it is clear that at some point directed propulsion could not come from pre-specified deterministic periodic deformation of the swimmer's body and we need to develop strategies for extracting a net directed motion from a series of random transitions in the conformation space of the swimmer. We present a theoretical formulation for describing the 'stochastic motor' that drives the motion of low Reynolds number swimmers based on this concept, and use it to study the propulsion of a simple low Reynolds number swimmer, namely, the three-sphere swimmer model. When the detailed balanced is broken and the motor is driven out of equilibrium, it can propel the swimmer in the required direction. The formulation can be used to study optimal design strategies for molecular scale low Reynolds number swimmers.

  16. Negative Numbers and Antimatter Particles

    NASA Astrophysics Data System (ADS)

    Tsan, Ung Chan

    Dirac's equation states that an electron implies the existence of an antielectron with the same mass (more generally same arithmetic properties) and opposite charge (more generally opposite algebraic properties). Subsequent observation of antielectron validated this concept. This statement can be extended to all matter particles; observation of antiproton, antineutron, antideuton … is in complete agreement with this view. Recently antihypertriton was observed and 38 atoms of antihydrogen were trapped. This opens the path for use in precise testing of nature's fundamental symmetries. The symmetric properties of a matter particle and its mirror antimatter particle seem to be well established. Interactions operate on matter particles and antimatter particles as well. Conservation of matter parallels addition operating on positive and negative numbers. Without antimatter particles, interactions of the Standard Model (electromagnetism, strong interaction and weak interaction) cannot have the structure of group. Antimatter particles are characterized by negative baryonic number A or/and negative leptonic number L. Materialization and annihilation obey conservation of A and L (associated to all known interactions), explaining why from pure energy (A = 0, L = 0) one can only obtain a pair of matter particle antimatter particle — electron antielectron, proton and antiproton — via materialization where the mass of a pair of particle antiparticle gives back to pure energy with annihilation. These two mechanisms cannot change the difference in the number of matter particles and antimatter particles. Thus from pure energy only a perfectly symmetric (in number) universe could be generated as proposed by Dirac but observation showed that our universe is not symmetric, it is a matter universe which is nevertheless neutral. Fall of reflection symmetries shattered the prejudice that there is no way to define in an absolute way right and left or matter and antimatter

  17. Transcriptional Regulation by the Numbers

    NASA Astrophysics Data System (ADS)

    Garcia, Hernan; Bintu, Lacramioara; Phillips, Rob

    2005-03-01

    The study of gene regulation and expression is becoming ever more quantitative. In particular, with increasing regularity the expression of genes is characterized quantitatively with respect to how much, when and where. The key argument of the present work is that such quantitative data demands quantitative models. We examine a class of models (``thermodynamic models'') which exploit the tools of statistical mechanics to compute the probability that RNA polymerase will be found at the appropriate promoter. Recent arguments have suggested that in some instances, the action of activators can be thought of strictly as agents of recruitment which increase the probability that RNA polymerase will be found at the promoter of interest. We develop an allied mathematical framework which describes the interactions of repressors, activators, helper molecules and RNA polymerase and culminates in an expression for the probability of RNA polymerase binding at the promoter of interest as a function of the concentrations of all of these regulatory agents. These ideas are applied to several case studies which illuminate the general formalism and shed light on the role of DNA looping.

  18. High Reynolds number research - 1980

    NASA Technical Reports Server (NTRS)

    Mckinney, L. W. (Editor); Baals, D. D. (Editor)

    1981-01-01

    The fundamental aerodynamic questions for which high Reynolds number experimental capability is required were examined. Potential experiments which maximize the research returns from the use of the National Transonic Facility (NTF) were outlined. Calibration plans were reviewed and the following topics were discussed: fluid dynamics; high lit; configuration aerodynamics; aeroelasticity and unsteady aerodynamics; wind tunnel/flight correlation; space vehicles; and theoretical aerodynamics

  19. Project Solo; Newsletter Number Eleven.

    ERIC Educational Resources Information Center

    Pittsburgh Univ., PA. Project Solo.

    An experimental 9th grade computer science syllabus is proposed. The syllabus would include the technical information needed for controlling and programing the computer in a number of modes and would preview some of the areas covered in the high school curriculum. A sample module of a topic not normally taught in high school--distance and…

  20. Not Just a Number Anymore

    ERIC Educational Resources Information Center

    Henderson, Nancy

    2008-01-01

    In the Essex, Cincinnati retirement center where they both worked as nurses, Holly Doherty and Michele Schavoir often heard aides complain about one longtime resident in particular. The patient kicks and screams and nurses can not stand to be around her. After a year of playing detective, Doherty found a number of the patient's relatives in…

  1. Adjuncts Build Strength in Numbers

    ERIC Educational Resources Information Center

    June, Audrey Williams

    2012-01-01

    When professors in positions that offer no chance of earning tenure begin to stack the faculty, campus dynamics start to change. Growing numbers of adjuncts make themselves more visible. They push for roles in governance, better pay and working conditions, and recognition for work well done. And they do so at institutions where tenured faculty,…

  2. Materiales. Numbers 17-20.

    ERIC Educational Resources Information Center

    Materiales, 1995

    1995-01-01

    Four booklets present articles on Spanish language and culture aimed at teachers of Spanish in the United States for student use in their classes. Number 17, "Los Jovenes Espanoles" (Spanish Youth), includes articles on Spanish youth sports, music, gangs, thoughts, and t-shirt slogans: (1) "Young Spanish Athletes"; (2) "Youth Music"; (3) "Urban…

  3. An Estimate of Avogadro's Number.

    ERIC Educational Resources Information Center

    Stauffer, Frederic R.

    1991-01-01

    Calculates an approximation to Avagadro's number for one mole of water by assuming the mole to be in cubical form and then halving the cube three times, thereby doubling the surface area of the original cube. The calculations are derived from the work necessary to perform these divisions. Presents calculated values for several liquids. (MDH)

  4. Winding number constrained contour detection.

    PubMed

    Ming, Yansheng; Li, Hongdong; He, Xuming

    2015-01-01

    Salient contour detection can benefit from the integration of both contour cues and region cues. However, this task is difficult due to different nature of region representations and contour representations. To solve this problem, this paper proposes an energy minimization framework based on winding number constraints. In this framework, both region cues, such as color/texture homogeneity, and contour cues, such as local contrast and continuity, are represented in a joint objective function, which has both region and contour labels. The key problem is how to design constraints that ensure the topological consistency of the two kinds of labels. Our technique is based on the topological concept of winding number. Using a fast method for winding number computation, a small number of linear constraints are derived to ensure label consistency. Our method is instantiated by ratio-based energy functions. By successfully integrating both region and contour cues, our method shows advantages over competitive methods. Our method is extended to incorporate user interaction, which leads to further improvements.

  5. Oxidation Numbers and Their Limitations.

    ERIC Educational Resources Information Center

    Woolf, A. A.

    1988-01-01

    Reviews a method for determining oxidation numbers in covalent compounds and balancing mixed organic-inorganic or purely organic systems. Points out ambiguities presented when adjacent atoms have small or zero electronegativity differences. Presents other limitations that arise when using electronegativity values. (CW)

  6. The elephant brain in numbers

    PubMed Central

    Herculano-Houzel, Suzana; Avelino-de-Souza, Kamilla; Neves, Kleber; Porfírio, Jairo; Messeder, Débora; Mattos Feijó, Larissa; Maldonado, José; Manger, Paul R.

    2014-01-01

    What explains the superior cognitive abilities of the human brain compared to other, larger brains? Here we investigate the possibility that the human brain has a larger number of neurons than even larger brains by determining the cellular composition of the brain of the African elephant. We find that the African elephant brain, which is about three times larger than the human brain, contains 257 billion (109) neurons, three times more than the average human brain; however, 97.5% of the neurons in the elephant brain (251 billion) are found in the cerebellum. This makes the elephant an outlier in regard to the number of cerebellar neurons compared to other mammals, which might be related to sensorimotor specializations. In contrast, the elephant cerebral cortex, which has twice the mass of the human cerebral cortex, holds only 5.6 billion neurons, about one third of the number of neurons found in the human cerebral cortex. This finding supports the hypothesis that the larger absolute number of neurons in the human cerebral cortex (but not in the whole brain) is correlated with the superior cognitive abilities of humans compared to elephants and other large-brained mammals. PMID:24971054

  7. Solar System Number-Crunching.

    ERIC Educational Resources Information Center

    Albrecht, Bob; Firedrake, George

    1997-01-01

    Defines terrestrial and Jovian planets and provides directions to obtain planetary data from the National Space Science Data Center Web sites. Provides "number-crunching" activities for the terrestrial planets using Texas Instruments TI-83 graphing calculators: computing volumetric mean radius and volume, density, ellipticity, speed, surface…

  8. Materiales. Numbers 21-23.

    ERIC Educational Resources Information Center

    Materiales, 1997

    1997-01-01

    These three journals of contemporary cultural, historical, and social interest contain activities designed to enhance the awareness of students of Spanish as a foreign language regarding the entire panorama of daily life in Spain. Number 21 focuses on the role of modern Spanish women; their career status; female authors; and the changing place of…

  9. Demonstratives and Number in Korean.

    ERIC Educational Resources Information Center

    Ree, Joe J.

    It is a generally held view that Korean lacks articles and that the category "number" in this language is unproductive. That is, the nouns in Korean can be used freely as definite and indefinite, and as singular and plural, without overt grammatical markers. Contrary to this view, the claim is made in this paper that non-unique nouns, i.e., nouns…

  10. Time to Make the Numbers

    ERIC Educational Resources Information Center

    Surrena, Michelle

    2011-01-01

    In order to inspire her students to work in mixed media, the author chose to highlight the art of Jasper Johns and Robert Indiana, both of whom used numbers and letters as a main focus in their art. In this article, the author describes a mixed-media printmaking project. (Contains 2 online resources.)

  11. Number Crunching: A Sheep's Tale

    ERIC Educational Resources Information Center

    Sam, Chris Lam

    2005-01-01

    In this article, the author talks about an allegorical tale which he has written as a message for teachers of mathematics. The story is about Gordon, who led a flock of small sheep. Gordon was a mathematics genius; however, his flock criticized his teaching of numbers and his boring lectures. His furry-god-farmer advised him to share his…

  12. Analytical and experimental study of fluid friction and heat transfer in low Reynolds number flow heat exchangers

    NASA Astrophysics Data System (ADS)

    Muzychka, Yuri Stephan

    1999-11-01

    Analysis of fluid friction and heat transfer in low Reynolds number flow heat exchangers is undertaken. Three configurations typically utilized in compact heat exchangers are examined. These are: the plain non- circular duct of constant cross-sectional area, the offset or interrupted strip fin, and the turbulator strip. Analytical models for each of these geometries are developed by combining asymptotic solutions using simple non-linear superposition. Models for predicting the friction factor-Reynolds number product, f Re, and Nusselt number, Nu, in non-circular ducts for hydrodynamically fully developed flow (HFDF), hydrodynamically developing flow (HDF), thermally fully developed flow (TFDF), thermally developing flow (TDF), and simultaneously developing flow (SDF) are developed. Thermal and hydrodynamic entrance models are developed by combining the asymptotic solutions for small and large values of the dimensionless duct length. Through the use of a novel characteristic length, the square root of the cross-sectional flow area, scatter in the dimensionless data for fully developed laminar flows is considerably reduced. Most numerical and analytical data are predicted within +/-10% for HFDF and TFDF, +/-12% for HDF and TDF, and +/-15% for SDF for most non-circular ducts. Simple analytic models for predicting the Fanning friction factor, f, and Colburn j factor of two common enhancement devices, the offset strip fin and the turbulator strip are developed from fundamental solutions of fluid dynamics and heat transfer. Models for the offset strip fin are valid over the full range of Reynolds numbers for rectangular and other non-circular sub-channel cross- sections. Model predictions for the offset strip fin agree with published experimental data within +/-20%. Models for the turbulator strip are valid over the full Reynolds number range for both straight and curved turbulator profiles. Model predictions for the turbulator strip agree with new experimental data to

  13. Effect of Péclet number on miscible rectilinear displacement in a Hele-Shaw cell

    NASA Astrophysics Data System (ADS)

    Pramanik, Satyajit; Mishra, Manoranjan

    2015-03-01

    The influence of fluid dispersion on the Saffman-Taylor instability in miscible fluids has been investigated in both the linear and the nonlinear regimes. The convective characteristic scales are used for the dimensionless formulation that incorporates the Péclet number (Pe) into the governing equations as a measure for the fluid dispersion. A linear stability analysis (LSA) is performed in a similarity transformation domain using the quasi-steady-state approximation. LSA results confirm that a flow with a large Pe has a higher growth rate than a flow with a small Pe. The critical Péclet number (Pec) for the onset of instability for all possible wave numbers and also a power-law relation of the onset time and most unstable wave number with Pe are observed. Unlike the radial source flow, Pec is found to vary with t0. A Fourier spectral method is used for direct numerical simulations (DNS) of the fully nonlinear system. The power-law dependence of the onset of instability ton on Pe is obtained from the DNS and found to be inversely proportional to Pe and it is in good agreement with that obtained from the LSA. The influence of the anisotropic dispersion is analyzed in both the linear and the nonlinear regimes. The results obtained confirm that for a weak transverse dispersion merging happens slowly and hence the small wave perturbations become unstable. We also observ that the onset of instability sets in early when the transverse dispersion is weak and varies with the anisotropic dispersion coefficient, ɛ , as ˜√{ɛ } , in compliance with the LSA. The combined effect of the Korteweg stress and Pe in the linear regime is pursued. It is observed that, depending on various flow parameters, a fluid system with a larger Pe exhibits a lower instantaneous growth rate than a system with a smaller Pe, which is contrary to the results when such stresses are absent.

  14. Statistical error in particle simulations of low mach number flows

    SciTech Connect

    Hadjiconstantinou, N G; Garcia, A L

    2000-11-13

    We present predictions for the statistical error due to finite sampling in the presence of thermal fluctuations in molecular simulation algorithms. The expressions are derived using equilibrium statistical mechanics. The results show that the number of samples needed to adequately resolve the flowfield scales as the inverse square of the Mach number. Agreement of the theory with direct Monte Carlo simulations shows that the use of equilibrium theory is justified.

  15. Lake number, a quantitative indicator of mixing used to estimate changes in dissolved oxygen

    USGS Publications Warehouse

    Robertson, Dale M.; Imberger, Jorg

    1994-01-01

    Lake Number, LN, values are shown to be quantitative indicators of deep mixing in lakes and reservoirs that can be used to estimate changes in deep water dissolved oxygen (DO) concentrations. LN is a dimensionless parameter defined as the ratio of the moments about the center of volume of the water body, of the stabilizing force of gravity associated with density stratification to the destabilizing forces supplied by wind, cooling, inflow, outflow, and other artificial mixing devices. To demonstrate the universality of this parameter, LN values are used to describe the extent of deep mixing and are compared with changes in DO concentrations in three reservoirs in Australia and four lakes in the U.S.A., which vary in productivity and mixing regimes. A simple model is developed which relates changes in LN values, i.e., the extent of mixing, to changes in near bottom DO concentrations. After calibrating the model for a specific system, it is possible to use real-time LN values, calculated using water temperature profiles and surface wind velocities, to estimate changes in DO concentrations (assuming unchanged trophic conditions).

  16. Granular-flow rheology: Role of shear-rate number in transition regime

    USGS Publications Warehouse

    Chen, C.-L.; Ling, C.-H.

    1996-01-01

    This paper examines the rationale behind the semiempirical formulation of a generalized viscoplastic fluid (GVF) model in the light of the Reiner-Rivlin constitutive theory and the viscoplastic theory, thereby identifying the parameters that control the rheology of granular flow. The shear-rate number (N) proves to be among the most significant parameters identified from the GVF model. As N ??? 0 and N ??? ???, the GVF model can reduce asymptotically to the theoretical stress versus shear-rate relations in the macroviscous and graininertia regimes, respectively, where the grain concentration (C) also plays a major role in the rheology of granular flow. Using available data obtained from the rotating-cylinder experiments of neutrally buoyant solid spheres dispersing in an interstitial fluid, the shear stress for granular flow in transition between the two regimes proves dependent on N and C in addition to some material constants, such as the coefficient of restitution. The insufficiency of data on rotating-cylinder experiments cannot presently allow the GVF model to predict how a granular flow may behave in the entire range of N; however, the analyzed data provide an insight on the interrelation among the relevant dimensionless parameters.

  17. Theory of cylindrical and spherical Langmuir probes in the limit of vanishing Debye number

    SciTech Connect

    Parrot, M.J.M.; Storey, L.R.O.; Parker, L.W.; Laframboise, J.G.

    1982-12-01

    A theory has been developed for cylindrical and spherical probes and other collectors in collisionless plasmas, in the limit where the ratio of Debye length to probe radius (the Debye number lambda/sub D/) vanishes. Results are presented for the case of equal electron and ion temperatures. On the scale of the probe radius, the distributions of potential and density in the presheath appear to have infinite slope at the probe surface. The dimensionless current--voltage characteristic is the same for the cylinder as for the sphere, within the limits of error of the numerical results, although no physical reason for this is evident. As the magnitude of probe potential (relative to space) increases, the current does not saturate abruptly but only asymptotically; its limiting value is about 45% larger than at space potential. Probe currents for small nonzero lambda/sub D/ approach those for zero lambda/sub D/ only very slowly, showing power-law behavior as function of lambda/sub D/ in the limit as lambda/sub D/ ..-->.. 0, with power-law exponents less than unity, resulting in infinite limiting derivatives with respect to lambda/sub D/.

  18. Nanofluid slip flow over a stretching cylinder with Schmidt and Péclet number effects

    NASA Astrophysics Data System (ADS)

    Md Basir, Md Faisal; Uddin, M. J.; Md. Ismail, A. I.; Bég, O. Anwar

    2016-05-01

    A mathematical model is presented for three-dimensional unsteady boundary layer slip flow of Newtonian nanofluids containing gyrotactic microorganisms over a stretching cylinder. Both hydrodynamic and thermal slips are included. By applying suitable similarity transformations, the governing equations are transformed into a set of nonlinear ordinary differential equations with appropriate boundary conditions. The transformed nonlinear ordinary differential boundary value problem is then solved using the Runge-Kutta-Fehlberg fourth-fifth order numerical method in Maple 18 symbolic software. The effects of the controlling parameters on the dimensionless velocity, temperature, nanoparticle volume fractions and microorganism motile density functions have been illustrated graphically. Comparisons of the present paper with the existing published results indicate good agreement and supports the validity and the accuracy of our numerical computations. Increasing bioconvection Schmidt number is observed to depress motile micro-organism density function. Increasing thermal slip parameter leads to a decrease in temperature. Thermal slip also exerts a strong influence on nano-particle concentration. The flow is accelerated with positive unsteadiness parameter (accelerating cylinder) and temperature and micro-organism density function are also increased. However nano-particle concentration is reduced with positive unsteadiness parameter. Increasing hydrodynamic slip is observed to boost temperatures and micro-organism density whereas it decelerates the flow and reduces nano-particle concentrations. The study is relevant to nano-biopolymer manufacturing processes.

  19. Number-theory dark matter

    NASA Astrophysics Data System (ADS)

    Nakayama, Kazunori; Takahashi, Fuminobu; Yanagida, Tsutomu T.

    2011-05-01

    We propose that the stability of dark matter is ensured by a discrete subgroup of the U(1)B-L gauge symmetry, Z(B-L). We introduce a set of chiral fermions charged under the U(1)B-L in addition to the right-handed neutrinos, and require the anomaly-cancellation conditions associated with the U(1)B-L gauge symmetry. We find that the possible number of fermions and their charges are tightly constrained, and that non-trivial solutions appear when at least five additional chiral fermions are introduced. The Fermat theorem in the number theory plays an important role in this argument. Focusing on one of the solutions, we show that there is indeed a good candidate for dark matter, whose stability is guaranteed by Z(B-L).

  20. Determination of the Schmidt number

    SciTech Connect

    Sperling, J.; Vogel, W.

    2011-04-15

    Optimized, necessary, and sufficient conditions for the identification of the Schmidt number will be derived in terms of general Hermitian operators. These conditions apply to arbitrary mixed quantum states. The optimization procedure delivers equations similar to the eigenvalue problem of an operator. The properties of the solution of these equations will be studied. We solve these equations for classes of operators. The solutions will be applied to phase randomized two-mode squeezed-vacuum states in continuous variable systems.

  1. Lozenge Tilings and Hurwitz Numbers

    NASA Astrophysics Data System (ADS)

    Novak, Jonathan

    2015-10-01

    We give a new proof of the fact that, near a turning point of the frozen boundary, the vertical tiles in a uniformly random lozenge tiling of a large sawtooth domain are distributed like the eigenvalues of a GUE random matrix. Our argument uses none of the standard tools of integrable probability. In their place, it uses a combinatorial interpretation of the Harish-Chandra/Itzykson-Zuber integral as a generating function for desymmetrized Hurwitz numbers.

  2. Approximate number sense, symbolic number processing, or number-space mappings: what underlies mathematics achievement?

    PubMed

    Sasanguie, Delphine; Göbel, Silke M; Moll, Kristina; Smets, Karolien; Reynvoet, Bert

    2013-03-01

    In this study, the performance of typically developing 6- to 8-year-old children on an approximate number discrimination task, a symbolic comparison task, and a symbolic and nonsymbolic number line estimation task was examined. For the first time, children's performances on these basic cognitive number processing tasks were explicitly contrasted to investigate which of them is the best predictor of their future mathematical abilities. Math achievement was measured with a timed arithmetic test and with a general curriculum-based math test to address the additional question of whether the predictive association between the basic numerical abilities and mathematics achievement is dependent on which math test is used. Results revealed that performance on both mathematics achievement tests was best predicted by how well childrencompared digits. In addition, an association between performance on the symbolic number line estimation task and math achievement scores for the general curriculum-based math test measuring a broader spectrum of skills was found. Together, these results emphasize the importance of learning experiences with symbols for later math abilities.

  3. Copy number variation and schizophrenia.

    PubMed

    St Clair, David

    2009-01-01

    Over the last 12 months, a series of major articles have reported associations with schizophrenia of copy number variants at 1q21, 15q11.2, 15q13.3, 16p11.2, 22q12, and Neurexin 1 loci. These are rare high-penetrant mutations that increase risk not only of schizophrenia but also of a range of other psychiatric disorders including autism and mental retardation. In some cases, the same phenotype can occur irrespective of whether the copy number variant causes a deletion or duplication. Some of these mutations occur at very high rates in human populations, but because of reduced fecundity associated with major psychiatric disorders the overall frequency in the population remains low. These new findings raise fundamental clinical and scientific questions concerning classification of major neuropsychiatric disorders, modes of inheritance, diagnostics, and genetic counseling. Although the loci identified so far account for only a small proportion of cases, many more are likely to be discovered over the next few years. A major focus of research will be to identify the key, the genetic and environmental determinants of schizophrenia risk in carriers of these copy number variants, and to discover whether their rates of mutation are unstable or fixed. PMID:18990708

  4. Vertebral numbers and human evolution.

    PubMed

    Williams, Scott A; Middleton, Emily R; Villamil, Catalina I; Shattuck, Milena R

    2016-01-01

    Ever since Tyson (1699), anatomists have noted and compared differences in the regional numbers of vertebrae among humans and other hominoids. Subsequent workers interpreted these differences in phylogenetic, functional, and behavioral frameworks and speculated on the history of vertebral numbers during human evolution. Even in a modern phylogenetic framework and with greatly expanded sample sizes of hominoid species, researchers' conclusions vary drastically, positing that hominins evolved from either a "long-backed" (numerically long lumbar column) or a "short-backed" (numerically short lumbar column) ancestor. We show that these disparate interpretations are due in part to the use of different criteria for what defines a lumbar vertebra, but argue that, regardless of which lumbar definition is used, hominins are similar to their great ape relatives in possessing a short trunk, a rare occurrence in mammals and one that defines the clade Hominoidea. Furthermore, we address the recent claim that the early hominin thoracolumbar configuration is not distinct from that of modern humans and conclude that early hominins show evidence of "cranial shifting," which might explain the anomalous morphology of several early hominin fossils. Finally, we evaluate the competing hypotheses on numbers of vertebrae and argue that the current data support a hominin ancestor with an African ape-like short trunk and lower back.

  5. Quasiperpendicular High Mach Number Shocks

    NASA Astrophysics Data System (ADS)

    Sulaiman, A. H.; Masters, A.; Dougherty, M. K.; Burgess, D.; Fujimoto, M.; Hospodarsky, G. B.

    2015-09-01

    Shock waves exist throughout the Universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this Letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasiperpendicular shocks across 2 orders of magnitude in Alfvén Mach number (MA ) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted time scale of ˜0.3 τc , where τc is the ion gyroperiod. In addition, we experimentally reveal the relationship between reformation and MA and focus on the magnetic structure of such shocks to further show that for the same MA , a reforming shock exhibits stronger magnetic field amplification than a shock that is not reforming.

  6. New Upper Bounds for Taxicab and Cabtaxi Numbers

    NASA Astrophysics Data System (ADS)

    Boyer, Christian

    2008-03-01

    Hardy was surprised by Ramanujan's remark about a London taxi numbered 1729: "it is a very interesting number, it is the smallest number expressible as a sum of two cubes in two different ways". In memory of this story, this number is now called Taxicab(2) = 1729 = 9^3 + 10^33 = 1^33 + 12^33, Taxicab(n) being the smallest number expressible in n ways as a sum of two cubes. We can generalize the problem by also allowing differences of cubes: Cabtaxi(n) is the smallest number expressible in n ways as a sum or difference of two cubes. For example, Cabtaxi(2) = 91 = 3^3 + 4^3 = 6^3 - 5^3. Results were only known up to Taxicab(6) and Cabtaxi(9). This paper presents a history of the two problems since Fermat, Frenicle and Viete, and gives new upper bounds for Taxicab(7) to Taxicab(19), and for Cabtaxi(10) to Cabtaxi(30). Decompositions are explicitly given up to Taxicab(12) and Cabtaxi(20).

  7. A Pseudo-Random Number Generator Based on Normal Numbers

    SciTech Connect

    Bailey, David H.

    2004-12-31

    In a recent paper, Richard Crandall and the present author established that each of a certain class of explicitly given real constants, uncountably infinite in number, is b-normal, for an integer that appears in the formula defining the constant. A b-normal constant is one where every string of m digits appears in the base-b expansion of the constant with limiting frequency b{sup -m}. This paper shows how this result can be used to fashion an efficient and effective pseudo-random number generator, which generates successive strings of binary digits from one of the constants in this class. The resulting generator, which tests slightly faster than a conventional linear congruential generator, avoids difficulties with large power-of-two data access strides that may occur when using conventional generators. It is also well suited for parallel processing--each processor can quickly and independently compute its starting value, with the collective sequence generated by all processors being the same as that generated by a single processor.

  8. Serial analysis of gene expression.

    PubMed

    Velculescu, V E; Zhang, L; Vogelstein, B; Kinzler, K W

    1995-10-20

    The characteristics of an organism are determined by the genes expressed within it. A method was developed, called serial analysis of gene expression (SAGE), that allows the quantitative and simultaneous analysis of a large number of transcripts. To demonstrate this strategy, short diagnostic sequence tags were isolated from pancreas, concatenated, and cloned. Manual sequencing of 1000 tags revealed a gene expression pattern characteristic of pancreatic function. New pancreatic transcripts corresponding to novel tags were identified. SAGE should provide a broadly applicable means for the quantitative cataloging and comparison of expressed genes in a variety of normal, developmental, and disease states. PMID:7570003

  9. A Numbering System for MFS Transporter Proteins

    PubMed Central

    Lee, Joanna; Sands, Zara A.; Biggin, Philip C.

    2016-01-01

    The Major Facilitator Superfamily (MFS) is one of the largest classes of secondary active transporters and is widely expressed in many domains of life. It is characterized by a common 12-transmembrane helix motif that allows the selective transport of a vast range of diverse substrates across the membrane. MFS transporters play a central role in many physiological processes and are increasingly recognized as potential drug targets. Despite intensive efforts, there are still only a handful of crystal structures and therefore homology modeling is likely to be a necessary process for providing models to interpret experiments for many years to come. However, the diversity of sequences and the multiple conformational states these proteins can exist in makes the process significantly more complicated, especially for sequences for which there is very little sequence identity to known templates. Inspired by the approach adopted many years ago for GPCRs, we have analyzed the large number of MFS sequences now available alongside the current structural information to propose a series of conserved contact points that can provide additional guidance for the homology modeling process. To enable cross-comparison across MFS models we also present a numbering scheme that can be used to provide a point of reference within each of the 12 transmembrane regions. PMID:27314000

  10. Who can escape the natural number bias in rational number tasks? A study involving students and experts.

    PubMed

    Obersteiner, Andreas; Hoof, Jo Van; Verschaffel, Lieven; Dooren, Wim Van

    2016-08-01

    Many learners have difficulties with rational number tasks because they persistently rely on their natural number knowledge, which is not always applicable. Studies show that such a natural number bias can mislead not only children but also educated adults. It is still unclear whether and under what conditions mathematical expertise enables people to be completely unaffected by such a bias on tasks in which people with less expertise are clearly biased. We compared the performance of eighth-grade students and expert mathematicians on the same set of algebraic expression problems that addressed the effect of arithmetic operations (multiplication and division). Using accuracy and response time measures, we found clear evidence for a natural number bias in students but no traces of a bias in experts. The data suggested that whereas students based their answers on their intuitions about natural numbers, expert mathematicians relied on their skilled intuitions about algebraic expressions. We conclude that it is possible for experts to be unaffected by the natural number bias on rational number tasks when they use strategies that do not involve natural numbers. PMID:26566736

  11. Who can escape the natural number bias in rational number tasks? A study involving students and experts.

    PubMed

    Obersteiner, Andreas; Hoof, Jo Van; Verschaffel, Lieven; Dooren, Wim Van

    2016-08-01

    Many learners have difficulties with rational number tasks because they persistently rely on their natural number knowledge, which is not always applicable. Studies show that such a natural number bias can mislead not only children but also educated adults. It is still unclear whether and under what conditions mathematical expertise enables people to be completely unaffected by such a bias on tasks in which people with less expertise are clearly biased. We compared the performance of eighth-grade students and expert mathematicians on the same set of algebraic expression problems that addressed the effect of arithmetic operations (multiplication and division). Using accuracy and response time measures, we found clear evidence for a natural number bias in students but no traces of a bias in experts. The data suggested that whereas students based their answers on their intuitions about natural numbers, expert mathematicians relied on their skilled intuitions about algebraic expressions. We conclude that it is possible for experts to be unaffected by the natural number bias on rational number tasks when they use strategies that do not involve natural numbers.

  12. Propulsion at low Reynolds number

    NASA Astrophysics Data System (ADS)

    Najafi, Ali; Golestanian, Ramin

    2005-04-01

    We study the propulsion of two model swimmers at low Reynolds number. Inspired by Purcell's model, we propose a very simple one-dimensional swimmer consisting of three spheres that are connected by two arms whose lengths can change between two values. The proposed swimmer can swim with a special type of motion, which breaks the time-reversal symmetry. We also show that an ellipsoidal membrane with tangential travelling wave on it can also propel itself in the direction preferred by the travelling wave. This system resembles the realistic biological animals like Paramecium.

  13. Valence, Covalence, Hypervalence, Oxidation State, and Coordination Number

    ERIC Educational Resources Information Center

    Smith, Derek W.

    2005-01-01

    Valence as a numerical measure of an atom's combining power, expressed by the number of bonds it forms in a molecular formulation of the compound in question, was unable to cope with coordination compounds. The covalence of an atom is the nearest model equivalent, but is subject to ambiguity since it often depends on which bonding model is being…

  14. Dynamic Modeling for Development and Education: From Concepts to Numbers

    ERIC Educational Resources Information Center

    Van Geert, Paul

    2014-01-01

    The general aim of the article is to teach the reader how to transform conceptual models of change, development, and learning into mathematical expressions and how to use these equations to build dynamic models by means of the widely used spreadsheet program Excel. The explanation is supported by a number of Excel files, which the reader can…

  15. 'Magic numbers' in the melting of a cluster of point charges on a sphere

    SciTech Connect

    Livshits, A. M. Lozovik, Yu. E.

    2010-11-15

    The thermodynamic properties of a cluster of point Coulomb charges on a sphere have been analyzed using the Monte Carlo method for the number of charges 20 {<=} N {<=} 90. The ground state of the system of charges is described in the model of a closed quasi-two-dimensional triangular lattice with topological defects. We have determined the dependence of the Lindeman parameter {delta}{sub L} of this system on N and on the dimensionless parameter, which is proportional to the temperature T and to the radius R of the cluster, where element is the dielectric constant of the medium and the charge of a particle. The 'magic numbers,' i.e., the N values, for which the melting point of the closed triangular lattice of charges is much higher than those for neighboring N values, have been found. The evolution of the lattice-melting mechanisms with an increase in the number of charges N in a mesoscopic cluster has been analyzed. For N {<=} 32, the melting of the lattice does not involve dislocations (nontopological melting); this behavior of the mesoscopic system of charges on the sphere differs from the behavior of the extended planar two-dimensional system. At N {>=} 50, melting is accompanied by the formation of dislocations. The mechanism of dislocation-free non-topological melting of a closed lattice, which occurs at small N values and is associated with the cooperative rotational motion of 'rings' of particles, has been analyzed. The model has various implementations in the mesoscopic region; in particular, it describes the system of electrons over the liquid-helium cluster, the liquid-helium cluster with incorporated charged particles, a multielectron bubble in liquid helium, a charged quantum dot, etc.

  16. Health manpower: numbers, distribution, quality.

    PubMed

    Petersdorf, R G

    1975-05-01

    Although the "health care crisis" was thought solvable by simply increasing the number of physicians, this has turned out not to be the case. The major problems in physician manpower are geographic maldistribution with a sparsity of physicians in the rural areas and the inner city and an overproduction of specialists. Certain changes in undergraduate and postgraduate medical education have contributed to this maldistribution. There is good evidence that there is an overproduction of surgeons and of medical subspecialists such as cardiologists. Much of the excess subspecialization can be laid at the foot of graduate training programs. The role of the specialty boards in affecting career choices and with them health manpower is analyzed. Some solutions to solve the geographic and specialty maldistribution problems are suggested. It is clear that more primary care physicians including general internists, family physicians, and pediatricians are needed.

  17. Indexing the approximate number system.

    PubMed

    Inglis, Matthew; Gilmore, Camilla

    2014-01-01

    Much recent research attention has focused on understanding individual differences in the approximate number system, a cognitive system believed to underlie human mathematical competence. To date researchers have used four main indices of ANS acuity, and have typically assumed that they measure similar properties. Here we report a study which questions this assumption. We demonstrate that the numerical ratio effect has poor test-retest reliability and that it does not relate to either Weber fractions or accuracy on nonsymbolic comparison tasks. Furthermore, we show that Weber fractions follow a strongly skewed distribution and that they have lower test-retest reliability than a simple accuracy measure. We conclude by arguing that in the future researchers interested in indexing individual differences in ANS acuity should use accuracy figures, not Weber fractions or numerical ratio effects. PMID:24361686

  18. Number of cosmic string loops

    NASA Astrophysics Data System (ADS)

    Blanco-Pillado, Jose J.; Olum, Ken D.; Shlaer, Benjamin

    2014-01-01

    Using recent simulation results, we provide the mass and speed spectrum of cosmic string loops. This is the quantity of primary interest for many phenomenological signatures of cosmic strings, and it can be accurately predicted using recently acquired detailed knowledge of the loop production function. We emphasize that gravitational smoothing of long strings plays a negligible role in determining the total number of existing loops. We derive a bound on the string tension imposed by recent constraints on the stochastic gravitational wave background from pulsar timing arrays, finding Gμ ≤2.8×10-9. We also provide a derivation of the Boltzmann equation for cosmic string loops in the language of differential forms.

  19. An experimental analysis of bed load transport in gravel-bed braided rivers with high grain Reynolds numbers

    NASA Astrophysics Data System (ADS)

    De Vincenzo, Annamaria; Brancati, Francesco; Pannone, Marilena

    2016-08-01

    Laboratory experiments were performed with nearly uniform fluvial gravel (D50=9 mm, D10=5 mm and D90=13 mm) to analyse the relationship between stream power and bed load transport rate in gravel-bed braided rivers at high grain Reynolds numbers. The values of the unit-width dimensionless bed-load rate qb* and unit-width dimensionless stream power ω* were evaluated in equilibrium conditions based on ten different experimental runs. Then, they were plotted along with values obtained during particularly representative field studies documented in the literature, and a regression law was derived. For comparison, a regression analysis was performed using the data obtained from laboratory experiments characterized by smaller grain sizes and, therefore, referring to relatively low grain Reynolds numbers. A numerical integration of Exner's equation was performed to reconstruct the local and time-dependent functional dependence of qb* and ω*. The results led to the following conclusions: 1) At equilibrium, the reach-averaged bed load transport rate is related to the reach-averaged stream power by different regression laws at high and low grain Reynolds numbers. Additionally, the transition from bed to suspended load transport is accelerated by low Re*, with the corresponding bed load discharge increasing with stream power at a lower, linear rate. 2) When tested against the gravel laboratory measurements, the high Re* power law derived in the present study performs considerably better than do previous formulas. 3) The longitudinal variability of the section-averaged equilibrium stream power is much more pronounced than that characterizing the bed load rate, at least for high Re*. Thus, the stream power and its local-scale heterogeneity seem to be directly responsible for transverse sediment re-distribution and, ultimately, for the determination of the spatial and temporal scales that characterize the gravel bedforms. 4) Finally, the stochastic interpretation of the wetted

  20. Getting DNA copy numbers without control samples

    PubMed Central

    2012-01-01

    Background The selection of the reference to scale the data in a copy number analysis has paramount importance to achieve accurate estimates. Usually this reference is generated using control samples included in the study. However, these control samples are not always available and in these cases, an artificial reference must be created. A proper generation of this signal is crucial in terms of both noise and bias. We propose NSA (Normality Search Algorithm), a scaling method that works with and without control samples. It is based on the assumption that genomic regions enriched in SNPs with identical copy numbers in both alleles are likely to be normal. These normal regions are predicted for each sample individually and used to calculate the final reference signal. NSA can be applied to any CN data regardless the microarray technology and preprocessing method. It also finds an optimal weighting of the samples minimizing possible batch effects. Results Five human datasets (a subset of HapMap samples, Glioblastoma Multiforme (GBM), Ovarian, Prostate and Lung Cancer experiments) have been analyzed. It is shown that using only tumoral samples, NSA is able to remove the bias in the copy number estimation, to reduce the noise and therefore, to increase the ability to detect copy number aberrations (CNAs). These improvements allow NSA to also detect recurrent aberrations more accurately than other state of the art methods. Conclusions NSA provides a robust and accurate reference for scaling probe signals data to CN values without the need of control samples. It minimizes the problems of bias, noise and batch effects in the estimation of CNs. Therefore, NSA scaling approach helps to better detect recurrent CNAs than current methods. The automatic selection of references makes it useful to perform bulk analysis of many GEO or ArrayExpress experiments without the need of developing a parser to find the normal samples or possible batches within the data. The method is

  1. CRC (Coordinating Research Council) octane number requirement survey, 1988

    SciTech Connect

    Not Available

    1989-08-01

    An annual statistical survey of octane number requirements of late-model vehicles is conducted by the Coordinating Research Council, Inc. Test data were obtained by nineteen companies on 391 1988 vehicles including passenger cars and light-duty trucks and vans, of which 155 were equipped with knock sensors. Maximum octane-number requirements were determined by testing at maximum-throttle conditions, as well as at part-throttle, with three unleaded fuel series of varying sensitivities. Requirements are expressed as the (R+M)/2 octane number, Research octane number, and Motor octane number of the reference fuel producing knock which was recurrent and repeatable at the lowest audible level. Estimated octane number requirements for the total vehicles are weighted in proportion to the 1988-vehicle-model production and/or sales figures. The maximum octane number requirements of 1988 models with average sensitivity unleaded fuels were 84.7 (R+M)/2 octane numbers at the 50% satisfaction level, and 89.3 (R+M)/2 octane numbers at the 90% satisfaction level. Comparison with previous Surveys are made in this report.

  2. Verification Challenges at Low Numbers

    SciTech Connect

    Benz, Jacob M.; Booker, Paul M.; McDonald, Benjamin S.

    2013-06-01

    Many papers have dealt with the political difficulties and ramifications of deep nuclear arms reductions, and the issues of “Going to Zero”. Political issues include extended deterrence, conventional weapons, ballistic missile defense, and regional and geo-political security issues. At each step on the road to low numbers, the verification required to ensure compliance of all parties will increase significantly. Looking post New START, the next step will likely include warhead limits in the neighborhood of 1000 . Further reductions will include stepping stones at1000 warheads, 100’s of warheads, and then 10’s of warheads before final elimination could be considered of the last few remaining warheads and weapons. This paper will focus on these three threshold reduction levels, 1000, 100’s, 10’s. For each, the issues and challenges will be discussed, potential solutions will be identified, and the verification technologies and chain of custody measures that address these solutions will be surveyed. It is important to note that many of the issues that need to be addressed have no current solution. In these cases, the paper will explore new or novel technologies that could be applied. These technologies will draw from the research and development that is ongoing throughout the national laboratory complex, and will look at technologies utilized in other areas of industry for their application to arms control verification.

  3. Small number preference in guiding attention.

    PubMed

    Cai, Yong-Chun; Li, Shuang-Xia

    2015-02-01

    Healthy individuals are usually biased toward small numbers when they are asked to mentally bisect number intervals or generate number sequences. Number magnitude may be represented spatially along a left-to-right mental number line. The preference for small numbers is believed to reflect the leftward spatial bias of this numerical representation. This study examined whether small numbers captured visual attention more than larger numbers. Participants were asked to detect a target pre-cued by a small or a large number. We found that the response was faster when the target was pre-cued by a small number than when pre-cued by a large number, suggesting that visual attention is preferentially allocated to small numbers. In addition, this attentional preference for small numbers was distinct for participants of different educational backgrounds. For science or engineering participants, this small number preference was enhanced by left-hand responding and was positively correlated with the small number preference in a random number generation task, suggesting that the small number preference was attributable to a leftward bias of the spatial representation. For liberal arts participants, however, left-hand responding did not enhance the small number preference and no correlations were found between the attention task and the random number generation task, suggesting that non-spatial processing mediated the small number preference. Our findings show that the small number preference occurs as early as the perceptual processing stage and distinct mechanisms underlie the preference for small numbers for participants with different educational backgrounds.

  4. Copy Number Profiling of Brazilian Astrocytomas

    PubMed Central

    Bidinotto, Lucas Tadeu; Torrieri, Raul; Mackay, Alan; Almeida, Gisele Caravina; Viana-Pereira, Marta; Cruvinel-Carloni, Adriana; Spina, Maria Luisa; Campanella, Nathalia Cristina; Pereira de Menezes, Weder; Clara, Carlos Afonso; Becker, Aline Paixão; Jones, Chris; Reis, Rui Manuel

    2016-01-01

    Copy number alterations (CNA) are one of the driving mechanisms of glioma tumorigenesis, and are currently used as important biomarkers in the routine setting. Therefore, we performed CNA profiling of 65 astrocytomas of distinct malignant grades (WHO grade I–IV) of Brazilian origin, using array-CGH and microsatellite instability analysis (MSI), and investigated their correlation with TERT and IDH1 mutational status and clinico-pathological features. Furthermore, in silico analysis using the Oncomine database was performed to validate our findings and extend the findings to gene expression level. We found that the number of genomic alterations increases in accordance with glioma grade. In glioblastomas (GBM), the most common alterations were gene amplifications (PDGFRA, KIT, KDR, EGFR, and MET) and deletions (CDKN2A and PTEN). Log-rank analysis correlated EGFR amplification and/or chr7 gain with better survival of the patients. MSI was observed in 11% of GBMs. A total of 69% of GBMs presented TERT mutation, whereas IDH1 mutation was most frequent in diffuse (85.7%) and anaplastic (100%) astrocytomas. The combination of 1p19q deletion and TERT and IDH1 mutational status separated tumor groups that showed distinct age of diagnosis and outcome. In silico validation pointed to less explored genes that may be worthy of future investigation, such as CDK2, DMRTA1, and MTAP. Herein, using an extensive integrated analysis, we indicated potentially important genes, not extensively studied in gliomas, that could be further explored to assess their biological and clinical impact in astrocytomas. PMID:27172220

  5. The precision of mapping between number words and the approximate number system predicts children's formal math abilities.

    PubMed

    Libertus, Melissa E; Odic, Darko; Feigenson, Lisa; Halberda, Justin

    2016-10-01

    Children can represent number in at least two ways: by using their non-verbal, intuitive approximate number system (ANS) and by using words and symbols to count and represent numbers exactly. Furthermore, by the time they are 5years old, children can map between the ANS and number words, as evidenced by their ability to verbally estimate numbers of items without counting. How does the quality of the mapping between approximate and exact numbers relate to children's math abilities? The role of the ANS-number word mapping in math competence remains controversial for at least two reasons. First, previous work has not examined the relation between verbal estimation and distinct subtypes of math abilities. Second, previous work has not addressed how distinct components of verbal estimation-mapping accuracy and variability-might each relate to math performance. Here, we addressed these gaps by measuring individual differences in ANS precision, verbal number estimation, and formal and informal math abilities in 5- to 7-year-old children. We found that verbal estimation variability, but not estimation accuracy, predicted formal math abilities, even when controlling for age, expressive vocabulary, and ANS precision, and that it mediated the link between ANS precision and overall math ability. These findings suggest that variability in the ANS-number word mapping may be especially important for formal math abilities.

  6. The precision of mapping between number words and the approximate number system predicts children's formal math abilities.

    PubMed

    Libertus, Melissa E; Odic, Darko; Feigenson, Lisa; Halberda, Justin

    2016-10-01

    Children can represent number in at least two ways: by using their non-verbal, intuitive approximate number system (ANS) and by using words and symbols to count and represent numbers exactly. Furthermore, by the time they are 5years old, children can map between the ANS and number words, as evidenced by their ability to verbally estimate numbers of items without counting. How does the quality of the mapping between approximate and exact numbers relate to children's math abilities? The role of the ANS-number word mapping in math competence remains controversial for at least two reasons. First, previous work has not examined the relation between verbal estimation and distinct subtypes of math abilities. Second, previous work has not addressed how distinct components of verbal estimation-mapping accuracy and variability-might each relate to math performance. Here, we addressed these gaps by measuring individual differences in ANS precision, verbal number estimation, and formal and informal math abilities in 5- to 7-year-old children. We found that verbal estimation variability, but not estimation accuracy, predicted formal math abilities, even when controlling for age, expressive vocabulary, and ANS precision, and that it mediated the link between ANS precision and overall math ability. These findings suggest that variability in the ANS-number word mapping may be especially important for formal math abilities. PMID:27348475

  7. 47 CFR 32.20 - Numbering convention.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... made by citing the account numbers to the right of the decimal point; e.g., Account 2232 rather than... FOR TELECOMMUNICATIONS COMPANIES General Instructions § 32.20 Numbering convention. (a) The number “32” (appearing to the left of the first decimal point) indicates the part number. (b) The numbers...

  8. 47 CFR 32.20 - Numbering convention.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... made by citing the account numbers to the right of the decimal point; e.g., Account 2232 rather than... FOR TELECOMMUNICATIONS COMPANIES General Instructions § 32.20 Numbering convention. (a) The number “32” (appearing to the left of the first decimal point) indicates the part number. (b) The numbers...

  9. Shear-induced clustering of Brownian colloids in associative polymer networks at moderate Péclet number

    NASA Astrophysics Data System (ADS)

    Kim, Juntae; Helgeson, Matthew E.

    2016-08-01

    We investigate shear-induced clustering and its impact on fluid rheology in polymer-colloid mixtures at moderate colloid volume fraction. By employing a thermoresponsive system that forms associative polymer-colloid networks, we present experiments of rheology and flow-induced microstructure on colloid-polymer mixtures in which the relative magnitudes of the time scales associated with relaxation of viscoelasticity and suspension microstructure are widely and controllably varied. In doing so, we explore several limits of relative magnitude of the relevant dimensionless shear rates, the Weissenberg number Wi and the Péclet number Pe. In all of these limits, we find that the fluid exhibits two distinct regimes of shear thinning at relatively low and high shear rates, in which the rheology collapses by scaling with Wi and Pe, respectively. Using three-dimensionally-resolved flow small-angle neutron scattering measurements, we observe clustering of the suspension above a critical shear rate corresponding to Pe ˜0.1 over a wide range of fluid conditions, having anisotropy with projected orientation along both the vorticity and compressional axes of shear. The degree of anisotropy is shown to scale with Pe. From this we formulate an empirical model for the shear stress and viscosity, in which the viscoelastic network stress is augmented by an asymptotic shear thickening contribution due to hydrodynamic clustering. Overall, our results elucidate the significant role of hydrodynamic interactions in contributing to shear-induced clustering of Brownian suspensions in viscoelastic liquids.

  10. Coding limits on the number of transcription factors

    PubMed Central

    Itzkovitz, Shalev; Tlusty, Tsvi; Alon, Uri

    2006-01-01

    Background Transcription factor proteins bind specific DNA sequences to control the expression of genes. They contain DNA binding domains which belong to several super-families, each with a specific mechanism of DNA binding. The total number of transcription factors encoded in a genome increases with the number of genes in the genome. Here, we examined the number of transcription factors from each super-family in diverse organisms. Results We find that the number of transcription factors from most super-families appears to be bounded. For example, the number of winged helix factors does not generally exceed 300, even in very large genomes. The magnitude of the maximal number of transcription factors from each super-family seems to correlate with the number of DNA bases effectively recognized by the binding mechanism of that super-family. Coding theory predicts that such upper bounds on the number of transcription factors should exist, in order to minimize cross-binding errors between transcription factors. This theory further predicts that factors with similar binding sequences should tend to have similar biological effect, so that errors based on mis-recognition are minimal. We present evidence that transcription factors with similar binding sequences tend to regulate genes with similar biological functions, supporting this prediction. Conclusion The present study suggests limits on the transcription factor repertoire of cells, and suggests coding constraints that might apply more generally to the mapping between binding sites and biological function. PMID:16984633

  11. FSHD: copy number variations on the theme of muscular dystrophy

    PubMed Central

    Cabianca, Daphne Selvaggia

    2010-01-01

    In humans, copy number variations (CNVs) are a common source of phenotypic diversity and disease susceptibility. Facioscapulohumeral muscular dystrophy (FSHD) is an important genetic disease caused by CNVs. It is an autosomal-dominant myopathy caused by a reduction in the copy number of the D4Z4 macrosatellite repeat located at chromosome 4q35. Interestingly, the reduction of D4Z4 copy number is not sufficient by itself to cause FSHD. A number of epigenetic events appear to affect the severity of the disease, its rate of progression, and the distribution of muscle weakness. Indeed, recent findings suggest that virtually all levels of epigenetic regulation, from DNA methylation to higher order chromosomal architecture, are altered at the disease locus, causing the de-regulation of 4q35 gene expression and ultimately FSHD. PMID:21149563

  12. A gene expression screen.

    PubMed Central

    Wang, Z; Brown, D D

    1991-01-01

    A gene expression screen identifies mRNAs that differ in abundance between two mRNA mixtures by a subtractive hybridization method. The two mRNA populations are converted to double-stranded cDNAs, fragmented, and ligated to linkers for polymerase chain reaction (PCR) amplification. The multiple cDNA fragments isolated from any given gene can be treated as alleles in a genetic screen. Probability analysis of the frequency with which multiple alleles are found provides an estimation of the total number of up- and down-regulated genes. We have applied this method to genes that are differentially expressed in amphibian tadpole tail tissue in the first 24 hr after thyroid hormone treatment, which ultimately induces tail resorption. We estimate that there are about 30 up-regulated genes; 16 have been isolated. Images PMID:1722336

  13. Hillslope subsurface flow similarity: Real-world tests of the hillslope Péclet number

    NASA Astrophysics Data System (ADS)

    Lyon, S. W.; Troch, P. A.

    2007-07-01

    dimensionless moments of the hillslopes' observed characteristic response function using hydraulic conductivities reported in the literature. The agreement between the observed and theoretical moments shows the promise of implementing the hillslope Péclet number as a similarity parameter to describe first-order hydrological response in humid environments.

  14. Small number preference in guiding attention.

    PubMed

    Cai, Yong-Chun; Li, Shuang-Xia

    2015-02-01

    Healthy individuals are usually biased toward small numbers when they are asked to mentally bisect number intervals or generate number sequences. Number magnitude may be represented spatially along a left-to-right mental number line. The preference for small numbers is believed to reflect the leftward spatial bias of this numerical representation. This study examined whether small numbers captured visual attention more than larger numbers. Participants were asked to detect a target pre-cued by a small or a large number. We found that the response was faster when the target was pre-cued by a small number than when pre-cued by a large number, suggesting that visual attention is preferentially allocated to small numbers. In addition, this attentional preference for small numbers was distinct for participants of different educational backgrounds. For science or engineering participants, this small number preference was enhanced by left-hand responding and was positively correlated with the small number preference in a random number generation task, suggesting that the small number preference was attributable to a leftward bias of the spatial representation. For liberal arts participants, however, left-hand responding did not enhance the small number preference and no correlations were found between the attention task and the random number generation task, suggesting that non-spatial processing mediated the small number preference. Our findings show that the small number preference occurs as early as the perceptual processing stage and distinct mechanisms underlie the preference for small numbers for participants with different educational backgrounds. PMID:25354972

  15. Shifted genus expanded W ∞ algebra and shifted Hurwitz numbers

    NASA Astrophysics Data System (ADS)

    Zheng, Quan

    2016-05-01

    We construct the shifted genus expanded W ∞ algebra, which is isomorphic to the central subalgebra A ∞ of infinite symmetric group algebra and to the shifted Schur symmetrical function algebra Λ* defined by Okounkov and Olshanskii. As an application, we get some differential equations for the generating functions of the shifted Hurwitz numbers; thus, we can express the generating functions in terms of the shifted genus expanded cut-and-join operators.

  16. Selection for increased allocation to offspring number under environmental unpredictability.

    PubMed

    Simons, A M

    2007-03-01

    According to life-history theory, the evolution of offspring size is constrained by the trade-off between allocation of resources to individual offspring and the number of offspring produced. Existing models explore the ecological consequences of offspring size, whereas number is invariably treated simply as an outcome of the trade-off with size. Here I ask whether there is a direct evolutionary advantage of increased allocation to offspring number under environmental unpredictability. Variable environments are expected to select for diversification in the timing of egg hatch and seed germination, yet the dependence of the expression of diversification strategies, and thus parental fitness, on offspring number has not previously been recognized. I begin by showing that well-established sampling theory predicts that a target bethedging diversification strategy is more reliably achieved as offspring number increases. I then use a simulation model to demonstrate that higher offspring number leads to greater geometric mean fitness under environmental uncertainty. Natural selection is thus expected to act directly to increase offspring number under assumptions of environmental unpredictability in season quality.

  17. The Decimal Number System and Young Children

    ERIC Educational Resources Information Center

    Harrison, John

    2006-01-01

    In this article, the author believes that a visual image of the number system is helpful to everyone, especially children, in understanding what is, after all, an abstract idea. The simplest model is the number line, a row of equally spaced numbers, starting at zero. This illustrates the continuous progression of the natural numbers, moving to the…

  18. Girotondo dei Numeri (A Ring of Numbers).

    ERIC Educational Resources Information Center

    Palandra, Maria; And Others

    This workbook in Italian for learning the numbers from one to ten is intended for use in a bilingual education setting. It is introduced and concluded by a song about playing "ring around the rosy" with numbers. Each paqe has a pen and ink drawing illustrating the number and a sentence about the picture and the number. (AMH)

  19. Avogadro Number and Mole: A Royal Confusion.

    ERIC Educational Resources Information Center

    Emiliani, Cesare

    1991-01-01

    There is a great deal of confusion in physics and chemistry textbooks, dictionaries, manuals, and handbooks about the definition of Avogadro's number and the term "mole." Avogadro's number is defined simply as the number of atomic mass units in one gram. Mole is defined as the mass of one Avogadro number of identical items. (Author/PR)

  20. Contextual Effects on Number-Time Interaction

    ERIC Educational Resources Information Center

    Lu, Aitao; Hodges, Bert; Zhang, Jijia; Zhang, John X.

    2009-01-01

    Time perception has long been known to be affected by numerical representations. Recent studies further demonstrate that when participants estimate the duration of Arabic numbers, number magnitude, though task-irrelevant, biases duration judgment to produce underestimation for smaller numbers and overestimation for larger numbers. Such effects…

  1. 14 CFR 47.15 - Identification number.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Identification number. 47.15 Section 47.15... REGISTRATION General § 47.15 Identification number. (a) Number required. An applicant for Aircraft Registration must place a U.S. identification number (registration mark) on his Aircraft Registration...

  2. 7 CFR 987.102 - Lot number.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Lot number. 987.102 Section 987.102 Agriculture... RIVERSIDE COUNTY, CALIFORNIA Administrative Rules Definitions § 987.102 Lot number. Lot number is synonymous with code and means a combination of letters or numbers, or both, acceptable to the Committee,...

  3. 14 CFR 47.15 - Registration number.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Registration number. 47.15 Section 47.15... REGISTRATION General § 47.15 Registration number. (a) Number required. An applicant for aircraft registration must place a U.S. registration number (registration mark) on the Aircraft Registration Application,...

  4. 7 CFR 75.48 - Identification number.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Identification number. 75.48 Section 75.48 Agriculture... number. The Director may require the use of official identification numbers in connection with seed certificated or sampled under the Act. When identification numbers are required, they shall be specified by...

  5. 7 CFR 29.32 - Identification number.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Identification number. 29.32 Section 29.32 Agriculture... INSPECTION Regulations Definitions § 29.32 Identification number. A number or a combination of letters and numbers in a design or mark approved by the Director, stamped, printed, or stenciled on a lot of...

  6. 7 CFR 75.48 - Identification number.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Identification number. 75.48 Section 75.48 Agriculture... number. The Director may require the use of official identification numbers in connection with seed certificated or sampled under the Act. When identification numbers are required, they shall be specified by...

  7. 7 CFR 900.5 - Docket number.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Docket number. 900.5 Section 900.5 Agriculture... Docket number. Each proceeding, immediately following its institution, shall be assigned a docket number by the hearing clerk and thereafter the proceeding may be referred to by such number....

  8. 7 CFR 900.5 - Docket number.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Docket number. 900.5 Section 900.5 Agriculture... Docket number. Each proceeding, immediately following its institution, shall be assigned a docket number by the hearing clerk and thereafter the proceeding may be referred to by such number....

  9. 7 CFR 987.102 - Lot number.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Lot number. 987.102 Section 987.102 Agriculture... RIVERSIDE COUNTY, CALIFORNIA Administrative Rules Definitions § 987.102 Lot number. Lot number is synonymous with code and means a combination of letters or numbers, or both, acceptable to the Committee,...

  10. 7 CFR 46.20 - Lot numbers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Lot numbers. 46.20 Section 46.20 Agriculture... Receivers § 46.20 Lot numbers. An identifying lot number shall be assigned to each shipment of produce to be sold on consignment or joint account or for the account of another person or firm. A lot number...

  11. 7 CFR 46.20 - Lot numbers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Lot numbers. 46.20 Section 46.20 Agriculture... Receivers § 46.20 Lot numbers. An identifying lot number shall be assigned to each shipment of produce to be sold on consignment or joint account or for the account of another person or firm. A lot number...

  12. Mental number space in three dimensions.

    PubMed

    Winter, Bodo; Matlock, Teenie; Shaki, Samuel; Fischer, Martin H

    2015-10-01

    A large number of experimental findings from neuroscience and experimental psychology demonstrated interactions between spatial cognition and numerical cognition. In particular, many researchers posited a horizontal mental number line, where small numbers are thought of as being to the left of larger numbers. This review synthesizes work on the mental association between space and number, indicating the existence of multiple spatial mappings: recent research has found associations between number and vertical space, as well as associations between number and near/far space. We discuss number space in three dimensions with an eye on potential origins of the different number mappings, and how these number mappings fit in with our current knowledge of brain organization and brain-culture interactions. We derive novel predictions and show how this research fits into a general view of cognition as embodied, grounded and situated.

  13. Integrated-Circuit Pseudorandom-Number Generator

    NASA Technical Reports Server (NTRS)

    Steelman, James E.; Beasley, Jeff; Aragon, Michael; Ramirez, Francisco; Summers, Kenneth L.; Knoebel, Arthur

    1992-01-01

    Integrated circuit produces 8-bit pseudorandom numbers from specified probability distribution, at rate of 10 MHz. Use of Boolean logic, circuit implements pseudorandom-number-generating algorithm. Circuit includes eight 12-bit pseudorandom-number generators, outputs are uniformly distributed. 8-bit pseudorandom numbers satisfying specified nonuniform probability distribution are generated by processing uniformly distributed outputs of eight 12-bit pseudorandom-number generators through "pipeline" of D flip-flops, comparators, and memories implementing conditional probabilities on zeros and ones.

  14. Temperature-dependent particle-number projected moment of inertia

    SciTech Connect

    Allal, N. H.; Fellah, M.; Benhamouda, N.; Oudih, M. R.

    2008-05-15

    Expressions of the parallel and perpendicular temperature-dependent particle-number projected nuclear moment of inertia have been established by means of a discrete projection method. They generalize that of the FTBCS method and are well adapted to numerical computation. The effects of particle-number fluctuations have been numerically studied for some even-even actinide nuclei by using the single-particle energies and eigenstates of a deformed Woods-Saxon mean field. It has been shown that the parallel moment of inertia is practically not modified by the use of the projection method. In contrast, the discrepancy between the projected and FTBCS perpendicular moment of inertia values may reach 5%. Moreover, the particle-number fluctuation effects vary not only as a function of the temperature but also as a function of the deformation for a given temperature. This is not the case for the system energy.

  15. On the number of limit cycles for perturbed pendulum equations

    NASA Astrophysics Data System (ADS)

    Gasull, A.; Geyer, A.; Mañosas, F.

    2016-08-01

    We consider perturbed pendulum-like equations on the cylinder of the form x ¨ + sin ⁡ (x) = ε∑s=0mQn,s (x)x˙s where Qn,s are trigonometric polynomials of degree n, and study the number of limit cycles that bifurcate from the periodic orbits of the unperturbed case ε = 0 in terms of m and n. Our first result gives upper bounds on the number of zeros of its associated first order Melnikov function, in both the oscillatory and the rotary regions. These upper bounds are obtained expressing the corresponding Abelian integrals in terms of polynomials and the complete elliptic functions of first and second kind. Some further results give sharp bounds on the number of zeros of these integrals by identifying subfamilies which are shown to be Chebyshev systems.

  16. The Translated Dowling Polynomials and Numbers

    PubMed Central

    Mangontarum, Mahid M.; Macodi-Ringia, Amila P.; Abdulcarim, Normalah S.

    2014-01-01

    More properties for the translated Whitney numbers of the second kind such as horizontal generating function, explicit formula, and exponential generating function are proposed. Using the translated Whitney numbers of the second kind, we will define the translated Dowling polynomials and numbers. Basic properties such as exponential generating functions and explicit formula for the translated Dowling polynomials and numbers are obtained. Convexity, integral representation, and other interesting identities are also investigated and presented. We show that the properties obtained are generalizations of some of the known results involving the classical Bell polynomials and numbers. Lastly, we established the Hankel transform of the translated Dowling numbers. PMID:27433494

  17. 40 CFR 86.1204 - Section numbering.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Test Procedures for New Gasoline-Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1204 Section numbering. The section numbering system set forth...

  18. 40 CFR 86.1204 - Section numbering.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Test Procedures for New Gasoline-Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.1204 Section numbering. The section numbering system set forth...

  19. Number Theory in the High School Classroom.

    ERIC Educational Resources Information Center

    Dence, Thomas

    1999-01-01

    Demonstrates some of the usefulness of number theory to students on the high school setting in four areas: Fibonacci numbers, Diophantine equations, continued fractions, and algorithms for computing pi. (ASK)

  20. Algebraic structures of sequences of numbers

    NASA Astrophysics Data System (ADS)

    Huang, I.-Chiau

    2012-09-01

    For certain sequences of numbers, commutative rings with a module structure over a non-commutative ring are constructed. Identities of these numbers are considered as realizations of algebraic relations.

  1. Quantity Cognition: Numbers, Numerosity, Zero and Mathematics.

    PubMed

    Harvey, Ben M

    2016-05-23

    Physical quantities differ from abstract numbers and mathematics, but recent results are revealing the neural representation of both: a new study demonstrates how an absence of quantity is transformed into a representation of zero as a number.

  2. Genetic variations in the PSMA3, PSMA6 and PSMC6 genes are associated with type 1 diabetes in Latvians and with expression level of number of UPS-related and T1DM-susceptible genes in HapMap individuals.

    PubMed

    Sjakste, Tatjana; Paramonova, Natalia; Osina, Kristine; Dokane, Kristine; Sokolovska, Jelizaveta; Sjakste, Nikolajs

    2016-04-01

    The ubiquitin-proteasome system (UPS), a key player of proteostasis network in the body, was implicated in type 1 diabetes mellitus (T1DM) pathogenesis. Polymorphisms in genes encoding proteasome subunits may potentially affect system efficiency. However, data in this field are still limited. To fulfil this gap, single nucleotide polymorphisms in the PSMB5 (rs11543947), PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genes were genotyped on susceptibility to T1DM in Latvians. The rs11543947 was found to be neutral and other loci manifested disease susceptibility, with rs1048990 and rs2348071 being the most significantly associated (P < 0.001; OR 2.042 [1.376-3.032] and OR 2.096 [1.415-3.107], respectively). Risk effect was associated with female phenotype for rs2277460 and family history for rs2277460, rs2295826 and rs2295827. Five-locus genotypes being at risk simultaneously at any two or more loci showed strong (P < 0.0001) T1DM association. The T1DM protective effects (P < 0.001) were shown for five-locus genotype and haplotype homozygous on common alleles and composed of common alleles, respectively. Using SNPexp data set, correlations have been revealed between the rs1048990, rs2295826, rs2295827 and rs2348071 T1DM risk genotypes and expression levels of 14 genes related to the UPS and 42 T1DM-susceptible genes encoding proteins involved in innate and adaptive immunity, antiviral response, insulin signalling, glucose-energy metabolism and other pathways implicated in T1DM pathogenesis. Genotype-phenotype and genotype-genotype clusterings support genotyping results. Our results provide evidence on new T1DM-susceptible loci in the PSMA3, PSMA6 and PSMC6 proteasome genes and give a new insight into the T1DM pathogenesis.

  3. 48 CFR 304.7001 - Numbering acquisitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Numbering acquisitions. 304.7001 Section 304.7001 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATIVE MATTERS Acquisition Instrument Identification Numbering System 304.7001 Numbering acquisitions....

  4. 14 CFR 47.15 - Registration number.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Registration number. 47.15 Section 47.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRCRAFT REGISTRATION General § 47.15 Registration number. (a) Number required. An applicant for aircraft...

  5. 7 CFR 29.32 - Identification number.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Identification number. 29.32 Section 29.32 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.32 Identification number. A number or a combination of letters...

  6. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1. (b) The continuity of NSA voyage numbers shall not change with... General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1....

  7. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1. (b) The continuity of NSA voyage numbers shall not change with... General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1....

  8. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1. (b) The continuity of NSA voyage numbers shall not change with... General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1....

  9. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1. (b) The continuity of NSA voyage numbers shall not change with... General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1....

  10. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1. (b) The continuity of NSA voyage numbers shall not change with... General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1....

  11. Evaluating Number Sense in Workforce Students

    ERIC Educational Resources Information Center

    Steinke, Dorothea A.

    2015-01-01

    Earlier institution-sponsored research revealed that about 20% of students in community college basic math and pre-algebra programs lacked a sense of part-whole relationships with whole numbers. Using the same tool with a group of 86 workforce students, about 75% placed five whole numbers on an empty number line in a way that indicated lack of…

  12. Fascinating Fibonaccis: Mystery and Magic in Numbers.

    ERIC Educational Resources Information Center

    Garland, Trudi Hammel

    This document presents activities and information related to Fibonacci numbers, which are based upon the Golden Ratio, in areas of the arts, sciences, and mathematics. The work is organized into eight chapters: (1) "Origins and Definitions"; (2) "Fibonacci Numbers in Nature"; (3) "Fibonacci Numbers in Art and Architecture"; (4) "Fibonacci Numbers…

  13. Children's Use of Number Line Estimation Strategies

    ERIC Educational Resources Information Center

    Peeters, Dominique; Degrande, Tine; Ebersbach, Mirjam; Verschaffel, Lieven; Luwel, Koen

    2016-01-01

    This study tested whether second graders use benchmark-based strategies when solving a number line estimation (NLE) task. Participants were assigned to one of three conditions based on the availability of benchmarks provided on the number line. In the bounded condition, number lines were only bounded at both sides by 0 and 200, while the midpoint…

  14. 46 CFR Sec. 7 - Job order numbering.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 8 2014-10-01 2014-10-01 false Job order numbering. Sec. 7 Section 7 Shipping MARITIME... REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP Contract number shall be inserted in every job order and supplemental...

  15. 46 CFR Sec. 7 - Job order numbering.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Job order numbering. Sec. 7 Section 7 Shipping MARITIME... REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP Contract number shall be inserted in every job order and supplemental...

  16. 46 CFR Sec. 7 - Job order numbering.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false Job order numbering. Sec. 7 Section 7 Shipping MARITIME... REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP Contract number shall be inserted in every job order and supplemental...

  17. 46 CFR Sec. 7 - Job order numbering.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 8 2012-10-01 2012-10-01 false Job order numbering. Sec. 7 Section 7 Shipping MARITIME... REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP Contract number shall be inserted in every job order and supplemental...

  18. 46 CFR Sec. 7 - Job order numbering.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Job order numbering. Sec. 7 Section 7 Shipping MARITIME... REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP Contract number shall be inserted in every job order and supplemental...

  19. 47 CFR 51.203 - Number portability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Number portability. 51.203 Section 51.203 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.203 Number portability. The rules governing number...

  20. A GWAS of teat number in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Number of functional teats is an important trait in commercial swine production. As litter size continues to increase, the number of teats must also increase to supply nutrition to all piglets. The pig displays considerable variation for number of teats; therefore, a genome-wide association (GWA) an...

  1. The Decimal Representation of Real Numbers

    ERIC Educational Resources Information Center

    Kalapodi, A.

    2010-01-01

    The representation of natural numbers in decimal form is an unequivocal procedure while for the representation of real numbers some ambiguities concerning the existence of infinitely many digits equal to 9 still emerge. One of the most frequently confronted misunderstandings is whether 0.999...equals 1 or not, and if not what number does this…

  2. Reading the World through Very Large Numbers

    ERIC Educational Resources Information Center

    Greer, Brian; Mukhopadhyay, Swapna

    2010-01-01

    One original, and continuing, source of interest in large numbers is observation of the natural world, such as trying to count the stars on a clear night or contemplation of the number of grains of sand on the seashore. Indeed, a search of the internet quickly reveals many discussions of the relative numbers of stars and grains of sand. Big…

  3. Developing Young Children's Multidigit Number Sense.

    ERIC Educational Resources Information Center

    Diezmann, Carmel M.; English, Lyn D.

    2001-01-01

    This article describes a series of enrichment experiences designed to develop young (ages 5 to 8) gifted children's understanding of large numbers, central to their investigation of space travel. It describes activities designed to teach reading of large numbers and exploring numbers to a thousand and then a million. (Contains ten references.) (DB)

  4. 49 CFR 230.47 - Boiler number.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Steam Gauges § 230.47 Boiler number. (a) Generally. The builder's number of the boiler, if known, shall... 49 Transportation 4 2010-10-01 2010-10-01 false Boiler number. 230.47 Section...

  5. 49 CFR 230.47 - Boiler number.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Steam Gauges § 230.47 Boiler number. (a) Generally. The builder's number of the boiler, if known, shall... 49 Transportation 4 2011-10-01 2011-10-01 false Boiler number. 230.47 Section...

  6. 49 CFR 230.47 - Boiler number.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Steam Gauges § 230.47 Boiler number. (a) Generally. The builder's number of the boiler, if known, shall... 49 Transportation 4 2012-10-01 2012-10-01 false Boiler number. 230.47 Section...

  7. 49 CFR 230.47 - Boiler number.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Steam Gauges § 230.47 Boiler number. (a) Generally. The builder's number of the boiler, if known, shall... 49 Transportation 4 2013-10-01 2013-10-01 false Boiler number. 230.47 Section...

  8. 49 CFR 230.47 - Boiler number.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Steam Gauges § 230.47 Boiler number. (a) Generally. The builder's number of the boiler, if known, shall... 49 Transportation 4 2014-10-01 2014-10-01 false Boiler number. 230.47 Section...

  9. 46 CFR 169.515 - Number required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Number required. 169.515 Section 169.515 Shipping COAST... and Firefighting Equipment Primary Lifesaving Equipment § 169.515 Number required. (a) Except as... additional inflatable liferafts to accommodate 25% of the persons on board or the number of...

  10. 20 CFR 404.1220 - Identification numbers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Identification numbers. 404.1220 Section 404... § 404.1220 Identification numbers. (a) State and local governments. When a State submits a modification... will assign a special identification number to each political subdivision included in that...

  11. 7 CFR 1.414 - Docket number.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Docket number. 1.414 Section 1.414 Agriculture Office... Conservation and Shortage Relief Act of 1990 (16 U.S.C. 620 et seq.) § 1.414 Docket number. Each proceeding, following its institution, shall be assigned a docket number by the Hearing Clerk, and thereafter...

  12. 46 CFR 10.207 - Identification number.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Identification number. 10.207 Section 10.207 Shipping... CREDENTIAL General Requirements for All Merchant Mariner Credentials § 10.207 Identification number. For recordkeeping purposes only, a mariner's official MMC identification number is the individual's social...

  13. 40 CFR 265.11 - Identification number.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Identification number. 265.11 Section... FACILITIES General Facility Standards § 265.11 Identification number. Every facility owner or operator must apply to EPA for an EPA identification number in accordance with the EPA notification procedures (45...

  14. 24 CFR 3280.6 - Serial number.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Serial number. 3280.6 Section 3280... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS General § 3280.6 Serial number. (a) A manufactured home serial number which will identify the manufacturer and the state in which the...

  15. 7 CFR 900.54 - Docket number.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Docket number. 900.54 Section 900.54 Agriculture... Governing Proceedings on Petitions To Modify or To Be Exempted From Marketing Orders § 900.54 Docket number. Each proceeding, immediately following its institution, shall be assigned a docket number by...

  16. 7 CFR 1.134 - Docket number.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Docket number. 1.134 Section 1.134 Agriculture Office... Adjudicatory Proceedings Instituted by the Secretary Under Various Statutes § 1.134 Docket number. Each proceeding, immediately following its institution, shall be assigned a docket number by the Hearing...

  17. 47 CFR 95.671 - Serial number.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Serial number. 95.671 Section 95.671 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO... number. The serial number of each CB transmitter must be engraved on the transmitter chassis....

  18. 7 CFR 29.133 - Identification number.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Identification number. 29.133 Section 29.133... REGULATIONS TOBACCO INSPECTION Regulations Miscellaneous § 29.133 Identification number. The Director may require the use of official identification numbers in connection with tobacco certificated or...

  19. 7 CFR 1.414 - Docket number.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Docket number. 1.414 Section 1.414 Agriculture Office... Conservation and Shortage Relief Act of 1990 (16 U.S.C. 620 et seq.) § 1.414 Docket number. Each proceeding, following its institution, shall be assigned a docket number by the Hearing Clerk, and thereafter...

  20. 46 CFR 10.207 - Identification number.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Identification number. 10.207 Section 10.207 Shipping... CREDENTIAL General Requirements for All Merchant Mariner Credentials § 10.207 Identification number. For recordkeeping purposes only, a mariner's official MMC identification number is the individual's social...

  1. 47 CFR 32.6622 - Number services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Number services. 32.6622 Section 32.6622... FOR TELECOMMUNICATIONS COMPANIES Instructions for Expense Accounts § 32.6622 Number services. This account shall include costs incurred in providing customer number and classified listings. This...

  2. 40 CFR 264.11 - Identification number.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Identification number. 264.11 Section... Facility Standards § 264.11 Identification number. Every facility owner or operator must apply to EPA for an EPA identification number in accordance with the EPA notification procedures (45 FR 12746)....

  3. 7 CFR 1.134 - Docket number.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Docket number. 1.134 Section 1.134 Agriculture Office... Adjudicatory Proceedings Instituted by the Secretary Under Various Statutes § 1.134 Docket number. Each proceeding, immediately following its institution, shall be assigned a docket number by the Hearing...

  4. 7 CFR 29.133 - Identification number.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Identification number. 29.133 Section 29.133... REGULATIONS TOBACCO INSPECTION Regulations Miscellaneous § 29.133 Identification number. The Director may require the use of official identification numbers in connection with tobacco certificated or...

  5. 46 CFR 169.515 - Number required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Number required. 169.515 Section 169.515 Shipping COAST... and Firefighting Equipment Primary Lifesaving Equipment § 169.515 Number required. (a) Except as... additional inflatable liferafts to accommodate 25% of the persons on board or the number of...

  6. 27 CFR 24.115 - Registry number.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Registry number. 24.115... OF THE TREASURY LIQUORS WINE Establishment and Operations Application § 24.115 Registry number. Upon approval of the application, the appropriate TTB officer will assign a registry number to the bonded...

  7. 7 CFR 1200.6 - Docket number.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Docket number. 1200.6 Section 1200.6 Agriculture... Governing Proceedings To Formulate and Amend an Order § 1200.6 Docket number. Each proceeding, immediately following its institution, shall be assigned a docket number by the hearing clerk and thereafter...

  8. 7 CFR 1200.6 - Docket number.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Docket number. 1200.6 Section 1200.6 Agriculture... Governing Proceedings To Formulate and Amend an Order § 1200.6 Docket number. Each proceeding, immediately following its institution, shall be assigned a docket number by the hearing clerk and thereafter...

  9. 47 CFR 51.203 - Number portability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Number portability. 51.203 Section 51.203 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.203 Number portability. The rules governing number...

  10. Identifying Fractions on a Number Line

    ERIC Educational Resources Information Center

    Wong, Monica

    2013-01-01

    Fractions are generally introduced to students using the part--whole model. Yet the number line is another important representation which can be used to build fraction concepts (Australian Curriculum Assessment and Reporting Authority [ACARA], 2012). Number lines are recognised as key in students' number development not only of fractions, but…

  11. 20 CFR 404.1220 - Identification numbers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Identification numbers. 404.1220 Section 404... § 404.1220 Identification numbers. (a) State and local governments. When a State submits a modification... will assign a special identification number to each political subdivision included in that...

  12. 40 CFR 265.11 - Identification number.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Identification number. 265.11 Section... FACILITIES General Facility Standards § 265.11 Identification number. Every facility owner or operator must apply to EPA for an EPA identification number in accordance with the EPA notification procedures (45...

  13. 47 CFR 32.6622 - Number services.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Number services. 32.6622 Section 32.6622... FOR TELECOMMUNICATIONS COMPANIES Instructions for Expense Accounts § 32.6622 Number services. This account shall include costs incurred in providing customer number and classified listings. This...

  14. 47 CFR 1.1405 - File numbers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false File numbers. 1.1405 Section 1.1405... Procedures § 1.1405 File numbers. Each complaint which appears to be essentially complete under § 1.1404 will be accepted and assigned a file number. Such assignment is for administrative purposes only and...

  15. 47 CFR 95.671 - Serial number.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Serial number. 95.671 Section 95.671 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO... number. The serial number of each CB transmitter must be engraved on the transmitter chassis....

  16. 7 CFR 900.54 - Docket number.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Docket number. 900.54 Section 900.54 Agriculture... Governing Proceedings on Petitions To Modify or To Be Exempted From Marketing Orders § 900.54 Docket number. Each proceeding, immediately following its institution, shall be assigned a docket number by...

  17. 27 CFR 24.115 - Registry number.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Registry number. 24.115... OF THE TREASURY LIQUORS WINE Establishment and Operations Application § 24.115 Registry number. Upon approval of the application, the appropriate TTB officer will assign a registry number to the bonded...

  18. 24 CFR 3280.6 - Serial number.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Serial number. 3280.6 Section 3280... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS General § 3280.6 Serial number. (a) A manufactured home serial number which will identify the manufacturer and the state in which the...

  19. 40 CFR 264.11 - Identification number.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Identification number. 264.11 Section... Facility Standards § 264.11 Identification number. Every facility owner or operator must apply to EPA for an EPA identification number in accordance with the EPA notification procedures (45 FR 12746)....

  20. 47 CFR 64.1506 - Number designation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Number designation. 64.1506 Section 64.1506... Number designation. Any interstate service described in § 64.1501(a)(1)-(2), and not subject to the exclusions contained in § 64.1501(a)(4), shall be offered only through telephone numbers beginning with a...

  1. Number-Theoretic Functions via Convolution Rings.

    ERIC Educational Resources Information Center

    Berberian, S. K.

    1992-01-01

    Demonstrates the number theory property that the number of divisors of an integer n times the number of positive integers k, less than or equal to and relatively prime to n, equals the sum of the divisors of n using theory developed about multiplicative functions, the units of a convolution ring, and the Mobius Function. (MDH)

  2. Plasmid Copy Number Determination by Quantitative Polymerase Chain Reaction.

    PubMed

    Anindyajati; Artarini, A Anita; Riani, Catur; Retnoningrum, Debbie S

    2016-01-01

    Recombinant therapeutic proteins are biopharmaceutical products that develop rapidly for years. Recombinant protein production in certain hosts requires vector expression harboring the gene encoding the corresponding protein. Escherichia coli is the prokaryote organism mostly used in recombinant protein production, commonly using a plasmid as the expression vector. Recombinant protein production is affected by plasmid copy number harboring the encoded gene, hence the determination of plasmid copy number also plays an important role in establishing a recombinant protein production system. On the industrial scale, a low copy number of plasmids are more suitable due to their better stability. In the previous study we constructed pCAD, a plasmid derived from the low copy number pBR322 plasmid. This study was aimed to confirm pCAD's copy number by quantitative polymerase chain reaction (qPCR). Plasmid copy number was determined by comparing the quantification signal from the plasmid to those from the chromosome. Copy number was then calculated by using a known copy number plasmid as a standard. Two pairs of primers, called tdk and ori, were designed for targeting a single gene tdk in the chromosome and a conserved domain in the plasmid's ori, respectively. Primer quality was analyzed in silico using PrimerSelect DNASTAR and PraTo software prior to in vitro evaluation on primer specificity and efficiency as well as optimization of qPCR conditions. Plasmid copy number determination was conducted on E. coli lysates harboring each plasmid, with the number of cells ranging from 10(2)-10(5) cells/μL. Cells were lysed by incubation at 95ºC for 10 minutes, followed by immediate freezing at -4°C. pBR322 plasmid with the copy number of ~19 copies/cell was used as the standard, while pJExpress414-sod plasmid possessing the high copy number pUC ori was also determined to test the method being used. In silico analysis based on primer-primer and primer-template interactions showed

  3. Processing Idiomatic Expressions: Effects of Semantic Compositionality

    ERIC Educational Resources Information Center

    Tabossi, Patrizia; Fanari, Rachele; Wolf, Kinou

    2008-01-01

    Three experiments tested the main claims of the idiom decomposition hypothesis: People have clear intuitions on the semantic compositionality of idiomatic expressions, which determines the syntactic behavior of these expressions and how they are recognized. Experiment 1 showed that intuitions are clear only for a very restricted number of…

  4. Gene Copy-Number Polymorphism Caused by Retrotransposition in Humans

    PubMed Central

    Galante, Pedro A. F.; Parmigiani, Raphael B.; Camargo, Anamaria A.; Hahn, Matthew W.; de Souza, Sandro J.

    2013-01-01

    The era of whole-genome sequencing has revealed that gene copy-number changes caused by duplication and deletion events have important evolutionary, functional, and phenotypic consequences. Recent studies have therefore focused on revealing the extent of variation in copy-number within natural populations of humans and other species. These studies have found a large number of copy-number variants (CNVs) in humans, many of which have been shown to have clinical or evolutionary importance. For the most part, these studies have failed to detect an important class of gene copy-number polymorphism: gene duplications caused by retrotransposition, which result in a new intron-less copy of the parental gene being inserted into a random location in the genome. Here we describe a computational approach leveraging next-generation sequence data to detect gene copy-number variants caused by retrotransposition (retroCNVs), and we report the first genome-wide analysis of these variants in humans. We find that retroCNVs account for a substantial fraction of gene copy-number differences between any two individuals. Moreover, we show that these variants may often result in expressed chimeric transcripts, underscoring their potential for the evolution of novel gene functions. By locating the insertion sites of these duplicates, we are able to show that retroCNVs have had an important role in recent human adaptation, and we also uncover evidence that positive selection may currently be driving multiple retroCNVs toward fixation. Together these findings imply that retroCNVs are an especially important class of polymorphism, and that future studies of copy-number variation should search for these variants in order to illuminate their potential evolutionary and functional relevance. PMID:23359205

  5. Is Approximate Number Precision a Stable Predictor of Math Ability?

    PubMed Central

    Libertus, Melissa E.; Feigenson, Lisa; Halberda, Justin

    2013-01-01

    Previous research shows that children’s ability to estimate numbers of items using their Approximate Number System (ANS) predicts later math ability. To more closely examine the predictive role of early ANS acuity on later abilities, we assessed the ANS acuity, math ability, and expressive vocabulary of preschoolers twice, six months apart. We also administered attention and memory span tasks to ask whether the previously reported association between ANS acuity and math ability is ANS-specific or attributable to domain-general cognitive skills. We found that early ANS acuity predicted math ability six months later, even when controlling for individual differences in age, expressive vocabulary, and math ability at the initial testing. In addition, ANS acuity was a unique concurrent predictor of math ability above and beyond expressive vocabulary, attention, and memory span. These findings of a predictive relationship between early ANS acuity and later math ability add to the growing evidence for the importance of early numerical estimation skills. PMID:23814453

  6. Mitochondrial DNA copy number variation across human cancers

    PubMed Central

    Reznik, Ed; Miller, Martin L; Şenbabaoğlu, Yasin; Riaz, Nadeem; Sarungbam, Judy; Tickoo, Satish K; Al-Ahmadie, Hikmat A; Lee, William; Seshan, Venkatraman E; Hakimi, A Ari; Sander, Chris

    2016-01-01

    Mutations, deletions, and changes in copy number of mitochondrial DNA (mtDNA), are observed throughout cancers. Here, we survey mtDNA copy number variation across 22 tumor types profiled by The Cancer Genome Atlas project. We observe a tendency for some cancers, especially of the bladder, breast, and kidney, to be depleted of mtDNA, relative to matched normal tissue. Analysis of genetic context reveals an association between incidence of several somatic alterations, including IDH1 mutations in gliomas, and mtDNA content. In some but not all cancer types, mtDNA content is correlated with the expression of respiratory genes, and anti-correlated to the expression of immune response and cell-cycle genes. In tandem with immunohistochemical evidence, we find that some tumors may compensate for mtDNA depletion to sustain levels of respiratory proteins. Our results highlight the extent of mtDNA copy number variation in tumors and point to related therapeutic opportunities. DOI: http://dx.doi.org/10.7554/eLife.10769.001 PMID:26901439

  7. An Evaluation of App-Based and Paper-Based Number Lines for Teaching Number Comparison

    ERIC Educational Resources Information Center

    Weng, Pei-Lin; Bouck, Emily C.

    2016-01-01

    Number comparison is a fundamental skill required for academic and functional mathematics (e.g., time, money, purchasing) for students with disabilities. The most commonly used method to teach number comparison is number lines. Although historically paper number lines are used, app-based number lines may offer greater flexibility. This study…

  8. 27 CFR 20.179 - Package identification number or serial number.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... number or serial number. 20.179 Section 20.179 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO... Package identification number or serial number. (a) Requirement. A dealer who fills packages with specially denatured spirits shall mark each package with a package identification number, in accordance...

  9. 27 CFR 20.179 - Package identification number or serial number.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... number or serial number. 20.179 Section 20.179 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO... Package identification number or serial number. (a) Requirement. A dealer who fills packages with specially denatured spirits shall mark each package with a package identification number, in accordance...

  10. Number and regulation of protozoan aquaporins reflect environmental complexity.

    PubMed

    Von Bülow, Julia; Beitz, Eric

    2015-08-01

    Protozoa are a diverse group of unicellular eukaryotes. Evidence has accumulated that protozoan aquaporin water and solute channels (AQP) contribute to adaptation in changing environments. Intracellular protozoan parasites live a well-sheltered life. Plasmodium spp. express a single AQP, Toxoplasma gondii two, while Trypanosoma cruzi and Leishamnia spp. encode up to five AQPs. Their AQPs are thought to import metabolic precursors and simultaneously to dispose of waste and to help parasites survive osmotic stress during transmission to and from the insect vector or during kidney passages. Trypanosoma brucei is a protozoan parasite that swims freely in the human blood. Expression and intracellular localization of the three T. brucei AQPs depend on the stage of differentiation during the life cycle, suggesting distinct roles in energy generation, metabolism, and cell motility. Free-living amoebae are in direct contact with the environment, encountering severe and sudden changes in the availability of nutrition, and in the osmotic conditions due to rainfall or drought. Amoeba proteus expresses a single AQP that is present in the contractile vacuole complex required for osmoregulation, whereas Dictyostelium discoideum expresses four AQPs, of which two are present in the single-celled amoeboidal stage and two more in the later multicellular stages preceding spore formation. The number and regulation of protozoan aquaporins may reflect environmental complexity. We highlight the gated AqpB from D. discoideum as an example of how life in the wild is challenged by a complex AQP structure-function relationship.

  11. Number and regulation of protozoan aquaporins reflect environmental complexity.

    PubMed

    Von Bülow, Julia; Beitz, Eric

    2015-08-01

    Protozoa are a diverse group of unicellular eukaryotes. Evidence has accumulated that protozoan aquaporin water and solute channels (AQP) contribute to adaptation in changing environments. Intracellular protozoan parasites live a well-sheltered life. Plasmodium spp. express a single AQP, Toxoplasma gondii two, while Trypanosoma cruzi and Leishamnia spp. encode up to five AQPs. Their AQPs are thought to import metabolic precursors and simultaneously to dispose of waste and to help parasites survive osmotic stress during transmission to and from the insect vector or during kidney passages. Trypanosoma brucei is a protozoan parasite that swims freely in the human blood. Expression and intracellular localization of the three T. brucei AQPs depend on the stage of differentiation during the life cycle, suggesting distinct roles in energy generation, metabolism, and cell motility. Free-living amoebae are in direct contact with the environment, encountering severe and sudden changes in the availability of nutrition, and in the osmotic conditions due to rainfall or drought. Amoeba proteus expresses a single AQP that is present in the contractile vacuole complex required for osmoregulation, whereas Dictyostelium discoideum expresses four AQPs, of which two are present in the single-celled amoeboidal stage and two more in the later multicellular stages preceding spore formation. The number and regulation of protozoan aquaporins may reflect environmental complexity. We highlight the gated AqpB from D. discoideum as an example of how life in the wild is challenged by a complex AQP structure-function relationship. PMID:26338868

  12. On the binary expansions of algebraic numbers

    SciTech Connect

    Bailey, David H.; Borwein, Jonathan M.; Crandall, Richard E.; Pomerance, Carl

    2003-07-01

    Employing concepts from additive number theory, together with results on binary evaluations and partial series, we establish bounds on the density of 1's in the binary expansions of real algebraic numbers. A central result is that if a real y has algebraic degree D > 1, then the number {number_sign}(|y|, N) of 1-bits in the expansion of |y| through bit position N satisfies {number_sign}(|y|, N) > CN{sup 1/D} for a positive number C (depending on y) and sufficiently large N. This in itself establishes the transcendency of a class of reals {summation}{sub n{ge}0} 1/2{sup f(n)} where the integer-valued function f grows sufficiently fast; say, faster than any fixed power of n. By these methods we re-establish the transcendency of the Kempner--Mahler number {summation}{sub n{ge}0}1/2{sup 2{sup n}}, yet we can also handle numbers with a substantially denser occurrence of 1's. Though the number z = {summation}{sub n{ge}0}1/2{sup n{sup 2}} has too high a 1's density for application of our central result, we are able to invoke some rather intricate number-theoretical analysis and extended computations to reveal aspects of the binary structure of z{sup 2}.

  13. Learning Exponents of Number on First Exposure to an L2

    ERIC Educational Resources Information Center

    Carroll, Susanne E.; Widjaja, Elizabeth

    2013-01-01

    Number lends itself to the study of how input interacts with transferred first language (L1) knowledge to facilitate or impede second language (L2) learning. We present data from adult English speakers exposed for the first time to Indonesian, a language that expresses number through bare noun phrases, reduplication and numeral + classifier…

  14. A developmental basis for stochasticity in floral organ numbers

    PubMed Central

    Kitazawa, Miho S.; Fujimoto, Koichi

    2014-01-01

    Stochasticity ubiquitously inevitably appears at all levels from molecular traits to multicellular, morphological traits. Intrinsic stochasticity in biochemical reactions underlies the typical intercellular distributions of chemical concentrations, e.g., morphogen gradients, which can give rise to stochastic morphogenesis. While the universal statistics and mechanisms underlying the stochasticity at the biochemical level have been widely analyzed, those at the morphological level have not. Such morphological stochasticity is found in foral organ numbers. Although the floral organ number is a hallmark of floral species, it can distribute stochastically even within an individual plant. The probability distribution of the floral organ number within a population is usually asymmetric, i.e., it is more likely to increase rather than decrease from the modal value, or vice versa. We combined field observations, statistical analysis, and mathematical modeling to study the developmental basis of the variation in floral organ numbers among 50 species mainly from Ranunculaceae and several other families from core eudicots. We compared six hypothetical mechanisms and found that a modified error function reproduced much of the asymmetric variation found in eudicot floral organ numbers. The error function is derived from mathematical modeling of floral organ positioning, and its parameters represent measurable distances in the floral bud morphologies. The model predicts two developmental sources of the organ-number distributions: stochastic shifts in the expression boundaries of homeotic genes and a semi-concentric (whorled-type) organ arrangement. Other models species- or organ-specifically reproduced different types of distributions that reflect different developmental processes. The organ-number variation could be an indicator of stochasticity in organ fate determination and organ positioning. PMID:25404932

  15. Multifractal Analysis of Sunspot Number Time Series

    NASA Astrophysics Data System (ADS)

    Kasde, Satish Kumar; Gwal, Ashok Kumar; Sondhiya, Deepak Kumar

    2016-07-01

    Multifractal analysis based approaches have been recently developed as an alternative framework to study the complex dynamical fluctuations in sunspot numbers data including solar cycles 20 to 23 and ascending phase of current solar cycle 24.To reveal the multifractal nature, the time series data of monthly sunspot number are analyzed by singularity spectrum and multi resolution wavelet analysis. Generally, the multifractility in sunspot number generate turbulence with the typical characteristics of the anomalous process governing the magnetosphere and interior of Sun. our analysis shows that singularities spectrum of sunspot data shows well Gaussian shape spectrum, which clearly establishes the fact that monthly sunspot number has multifractal character. The multifractal analysis is able to provide a local and adaptive description of the cyclic components of sunspot number time series, which are non-stationary and result of nonlinear processes. Keywords: Sunspot Numbers, Magnetic field, Multifractal analysis and wavelet Transform Techniques.

  16. Deafness for the meanings of number words.

    PubMed

    Caño, Agnès; Rapp, Brenda; Costa, Albert; Juncadella, Montserrat

    2008-01-15

    We describe the performance of an aphasic individual who showed a selective impairment affecting his comprehension of auditorily presented number words and not other word categories. His difficulty in number word comprehension was restricted to the auditory modality, given that with visual stimuli (written words, Arabic numerals and pictures) his comprehension of number and non-number words was intact. While there have been previous reports of selective difficulty or sparing of number words at the semantic and post-semantic levels, this is the first reported case of a pre-semantic deficit that is specific to the category of number words. This constitutes evidence that lexical semantic distinctions are respected by modality-specific neural mechanisms responsible for providing access to the meanings of words.

  17. Self-correcting random number generator

    DOEpatents

    Humble, Travis S.; Pooser, Raphael C.

    2016-09-06

    A system and method for generating random numbers. The system may include a random number generator (RNG), such as a quantum random number generator (QRNG) configured to self-correct or adapt in order to substantially achieve randomness from the output of the RNG. By adapting, the RNG may generate a random number that may be considered random regardless of whether the random number itself is tested as such. As an example, the RNG may include components to monitor one or more characteristics of the RNG during operation, and may use the monitored characteristics as a basis for adapting, or self-correcting, to provide a random number according to one or more performance criteria.

  18. Deafness for the meanings of number words

    PubMed Central

    Caño, Agnès; Rapp, Brenda; Costa, Albert; Juncadella, Montserrat

    2008-01-01

    We describe the performance of an aphasic individual who showed a selective impairment affecting his comprehension of auditorily presented number words and not other word categories. His difficulty in number word comprehension was restricted to the auditory modality, given that with visual stimuli (written words, Arabic numerals and pictures) his comprehension of number and non-number words was intact. While there have been previous reports of selective difficulty or sparing of number words at the semantic and post-semantic levels, this is the first reported case of a pre-semantic deficit that is specific to the category of number words. This constitutes evidence that lexical semantic distinctions are respected by modality-specific neural mechanisms responsible for providing access to the meanings of words. PMID:17915265

  19. Factoring numbers with a single interferogram

    SciTech Connect

    Tamma, Vincenzo; Zhang Heyi; He Xuehua; Shih Yanhua; Garuccio, Augusto; Schleich, Wolfgang P.

    2011-02-15

    We construct an analog computer based on light interference to encode the hyperbolic function f({zeta}){identical_to}1/{zeta} into a sequence of skewed curlicue functions. The resulting interferogram when scaled appropriately allows us to find the prime number decompositions of integers. We implement this idea exploiting polychromatic optical interference in a multipath interferometer and factor seven-digit numbers. We give an estimate for the largest number that can be factored by this scheme.

  20. Demonstrations of the Enormity of Avogadro's Number.

    ERIC Educational Resources Information Center

    Diemente, Damon

    1998-01-01

    Describes three calculations used to make students aware of the size of Avogadro's number: (1) the new size of a 6-inch diameter ball with volume increased by a factor of Avogadro's number; (2) the number of moles of sand grains in the Sahara Desert; and (3) the dimensions and length of a mole of hydrogen atoms shaped into a cube, a square, and a…