WorldWideScience

Sample records for large variable gain

  1. Beyond Multiplexing Gain in Large MIMO Systems

    DEFF Research Database (Denmark)

    Cakmak, Burak; Müller, Ralf R.; Fleury, Bernard Henri

    growth (multiplexing gain). Even when the channel entries are i.i.d. the deviation from the linear growth is significant. We also find an additive property of the deviation for a concatenated MIMO system. Finally, we quantify the deviation of the large SNR capacity from the exact capacity and find...

  2. Predictive Variable Gain Iterative Learning Control for PMSM

    Directory of Open Access Journals (Sweden)

    Huimin Xu

    2015-01-01

    Full Text Available A predictive variable gain strategy in iterative learning control (ILC is introduced. Predictive variable gain iterative learning control is constructed to improve the performance of trajectory tracking. A scheme based on predictive variable gain iterative learning control for eliminating undesirable vibrations of PMSM system is proposed. The basic idea is that undesirable vibrations of PMSM system are eliminated from two aspects of iterative domain and time domain. The predictive method is utilized to determine the learning gain in the ILC algorithm. Compression mapping principle is used to prove the convergence of the algorithm. Simulation results demonstrate that the predictive variable gain is superior to constant gain and other variable gains.

  3. MOS current gain cells with electronically variable gain and constant bandwidth

    NARCIS (Netherlands)

    Klumperink, Eric A.M.; Seevinck, Evert

    1989-01-01

    Two MOS current gain cells are proposed that provide linear amplification of currents supplied by several linear MOS V-I converters. The gain is electronically variable by a voltage or a current and can be made insensitive to temperature and IC processing. The gain cells have a constant

  4. Gain tuning and fidelity in continuous-variable quantum teleportation

    International Nuclear Information System (INIS)

    Ide, Toshiki; Hofmann, Holger F.; Furusawa, Akira; Kobayashi, Takayoshi

    2002-01-01

    The fidelity of continuous-variable teleportation can be optimized by changing the gain in the modulation of the output field. We discuss the gain dependence of fidelity for coherent, vacuum, and one-photon inputs and propose optimal gain tuning strategies for corresponding input selections

  5. Robust Optimal Adaptive Control Method with Large Adaptive Gain

    Science.gov (United States)

    Nguyen, Nhan T.

    2009-01-01

    In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly. However, a large adaptive gain can lead to high-frequency oscillations which can adversely affect robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient stability robustness. Simulations were conducted for a damaged generic transport aircraft with both standard adaptive control and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model while maintaining a sufficient time delay margin.

  6. A digital gain stabilizer for large volume organic scintillation detectors

    International Nuclear Information System (INIS)

    Braunsfurth, J.; Geske, K.

    1976-01-01

    A digital gain stabilizer is described, optimized for use with photomultipliers mounted on large volume organic scintillators, or other radiation detectors, which exhibit no prominent peaks in their amplitude spectra. As applications of this kind usually involve many phototubes or detectors, circuit simplicity, production reproduceability, and the possibility of computer controlled operation were major design criteria. Two versions were built, the first one using standard TTL-SSI and MSI circuitry, the second one - to reduce power requirements - using a mixture of TTL- and CMOS-LSI circuits. (Auth.)

  7. Assigning probability gain for precursors of four large Chinese earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Cao, T.; Aki, K.

    1983-03-10

    We extend the concept of probability gain associated with a precursor (Aki, 1981) to a set of precursors which may be mutually dependent. Making use of a new formula, we derive a criterion for selecting precursors from a given data set in order to calculate the probability gain. The probabilities per unit time immediately before four large Chinese earthquakes are calculated. They are approximately 0.09, 0.09, 0.07 and 0.08 per day for 1975 Haicheng (M = 7.3), 1976 Tangshan (M = 7.8), 1976 Longling (M = 7.6), and Songpan (M = 7.2) earthquakes, respectively. These results are encouraging because they suggest that the investigated precursory phenomena may have included the complete information for earthquake prediction, at least for the above earthquakes. With this method, the step-by-step approach to prediction used in China may be quantified in terms of the probability of earthquake occurrence. The ln P versus t curve (where P is the probability of earthquake occurrence at time t) shows that ln P does not increase with t linearly but more rapidly as the time of earthquake approaches.

  8. Large conservation gains possible for global biodiversity facets

    Science.gov (United States)

    Pollock, Laura J.; Thuiller, Wilfried; Jetz, Walter

    2017-06-01

    Different facets of biodiversity other than species numbers are increasingly appreciated as critical for maintaining the function of ecosystems and their services to humans. While new international policy and assessment processes such as the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) recognize the importance of an increasingly global, quantitative and comprehensive approach to biodiversity protection, most insights are still focused on a single facet of biodiversity—species. Here we broaden the focus and provide an evaluation of how much of the world’s species, functional and phylogenetic diversity of birds and mammals is currently protected and the scope for improvement. We show that the large existing gaps in the coverage for each facet of diversity could be remedied by a slight expansion of protected areas: an additional 5% of the land has the potential to more than triple the protected range of species or phylogenetic or functional units. Further, the same areas are often priorities for multiple diversity facets and for both taxa. However, we find that the choice of conservation strategy has a fundamental effect on outcomes. It is more difficult (that is, requires more land) to maximize basic representation of the global biodiversity pool than to maximize local diversity. Overall, species and phylogenetic priorities are more similar to each other than they are to functional priorities, and priorities for the different bird biodiversity facets are more similar than those of mammals. Our work shows that large gains in biodiversity protection are possible, while also highlighting the need to explicitly link desired conservation objectives and biodiversity metrics. We provide a framework and quantitative tools to advance these goals for multi-faceted biodiversity conservation.

  9. Large conservation gains possible for global biodiversity facets.

    Science.gov (United States)

    Pollock, Laura J; Thuiller, Wilfried; Jetz, Walter

    2017-06-01

    Different facets of biodiversity other than species numbers are increasingly appreciated as critical for maintaining the function of ecosystems and their services to humans. While new international policy and assessment processes such as the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) recognize the importance of an increasingly global, quantitative and comprehensive approach to biodiversity protection, most insights are still focused on a single facet of biodiversity-species. Here we broaden the focus and provide an evaluation of how much of the world's species, functional and phylogenetic diversity of birds and mammals is currently protected and the scope for improvement. We show that the large existing gaps in the coverage for each facet of diversity could be remedied by a slight expansion of protected areas: an additional 5% of the land has the potential to more than triple the protected range of species or phylogenetic or functional units. Further, the same areas are often priorities for multiple diversity facets and for both taxa. However, we find that the choice of conservation strategy has a fundamental effect on outcomes. It is more difficult (that is, requires more land) to maximize basic representation of the global biodiversity pool than to maximize local diversity. Overall, species and phylogenetic priorities are more similar to each other than they are to functional priorities, and priorities for the different bird biodiversity facets are more similar than those of mammals. Our work shows that large gains in biodiversity protection are possible, while also highlighting the need to explicitly link desired conservation objectives and biodiversity metrics. We provide a framework and quantitative tools to advance these goals for multi-faceted biodiversity conservation.

  10. Determinants of Cattle Feeding Profit and Cost of Gain Variability

    OpenAIRE

    Schroeder, Ted C.; Albright, Martin L.; Langemeier, Michael R.; Mintert, James R.

    1993-01-01

    Cattle feeders face risks from fluctuating fed cattle, feeder cattle, and feed prices and cattle performance. Closeout data on 7293 pens of steers are studied to determine the relative impacts of prices and animal performance on cattle feeding profits and cost of gain. Results indicate the importance of managing price risk.

  11. A CMOS variable gain amplifier for PHENIX electromagnetic calorimeter and RICH energy measurements

    Energy Technology Data Exchange (ETDEWEB)

    Wintenberg, A.L.; Simpson, M.L.; Young, G.R. [Oak Ridge National Lab., TN (United States); Palmer, R.L.; Moscone, C.G.; Jackson, R.G. [Tennessee Univ., Knoxville, TN (United States)

    1996-12-31

    A variable gain amplifier (VGA) has been developed equalizing the gains of integrating amplifier channels used with multiple photomultiplier tubes operating from common high-voltage supplies. The PHENIX lead-scintillator electromagnetic calorimeter will operate in that manner, and gain equalization is needed to preserve the dynamic range of the analog memory and ADC following the integrating amplifier. The VGA is also needed for matching energy channel gains prior to forming analog sums for trigger purposes. The gain of the VGA is variable over a 3:1 range using a 5-bit digital control, and the risetime is held between 15 and 23 ns using switched compensation in the VGA. An additional feature is gated baseline restoration. Details of the design and results from several prototype devices fabricated in 1.2-{mu}m Orbit CMOS are presented.

  12. Variability in large-scale wind power generation: Variability in large-scale wind power generation

    Energy Technology Data Exchange (ETDEWEB)

    Kiviluoma, Juha [VTT Technical Research Centre of Finland, Espoo Finland; Holttinen, Hannele [VTT Technical Research Centre of Finland, Espoo Finland; Weir, David [Energy Department, Norwegian Water Resources and Energy Directorate, Oslo Norway; Scharff, Richard [KTH Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Söder, Lennart [Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Menemenlis, Nickie [Institut de recherche Hydro-Québec, Montreal Canada; Cutululis, Nicolaos A. [DTU, Wind Energy, Roskilde Denmark; Danti Lopez, Irene [Electricity Research Centre, University College Dublin, Dublin Ireland; Lannoye, Eamonn [Electric Power Research Institute, Palo Alto California USA; Estanqueiro, Ana [LNEG, Laboratorio Nacional de Energia e Geologia, UESEO, Lisbon Spain; Gomez-Lazaro, Emilio [Renewable Energy Research Institute and DIEEAC/EDII-AB, Castilla-La Mancha University, Albacete Spain; Zhang, Qin [State Grid Corporation of China, Beijing China; Bai, Jianhua [State Grid Energy Research Institute Beijing, Beijing China; Wan, Yih-Huei [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA; Milligan, Michael [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA

    2015-10-25

    The paper demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics include probability distribution for different ramp durations, seasonal and diurnal variability and low net load events. The comparison shows regions with low variability (Sweden, Spain and Germany), medium variability (Portugal, Ireland, Finland and Denmark) and regions with higher variability (Quebec, Bonneville Power Administration and Electric Reliability Council of Texas in North America; Gansu, Jilin and Liaoning in China; and Norway and offshore wind power in Denmark). For regions with low variability, the maximum 1 h wind ramps are below 10% of nominal capacity, and for regions with high variability, they may be close to 30%. Wind power variability is mainly explained by the extent of geographical spread, but also higher capacity factor causes higher variability. It was also shown how wind power ramps are autocorrelated and dependent on the operating output level. When wind power was concentrated in smaller area, there were outliers with high changes in wind output, which were not present in large areas with well-dispersed wind power.

  13. Relationship between health services, socioeconomic variables and inadequate weight gain among Brazilian children.

    Science.gov (United States)

    de Souza, A C; Peterson, K E; Cufino, E; Gardner, J; Craveiro, M V; Ascherio, A

    1999-01-01

    This ecological analysis assessed the relative contribution of behavioural, health services and socioeconomic variables to inadequate weight gain in infants (0-11 months) and children (12-23 months) in 140 municipalities in the State of Ceara, north-east Brazil. To assess the total effect of selected variables, we fitted three unique sets of multivariate linear regression models to the prevalence of inadequate weight gain in infants and in children. The final predictive models included variables from the three sets. Findings showed that participation in growth monitoring and urbanization were inversely and significantly associated with the prevalence of inadequate weight gain in infants, accounting for 38.3% of the variation. Female illiteracy rate, participation in growth monitoring and degree of urbanization were all positively associated with prevalence of inadequate weight gain in children. Together, these factors explained 25.6% of the variation. Our results suggest that efforts to reduce the average municipality-specific female illiteracy rate, in combination with participation in growth monitoring, may be effective in reducing municipality-level prevalence of inadequate weight gain in infants and children in Ceara.

  14. Double-differential recording and AGC using microcontrolled variable gain ASIC.

    Science.gov (United States)

    Rieger, Robert; Deng, Shin-Liang

    2013-01-01

    Low-power wearable recording of biopotentials requires acquisition front-ends with high common-mode rejection for interference suppression and adjustable gain to provide an optimum signal range to a cascading analogue-to-digital stage. A microcontroller operated double-differential (DD) recording setup and automatic gain control circuit (AGC) are discussed which reject common-mode interference and provide tunable gain, thus compensating for imbalance and variation in electrode interface impedance. Custom-designed variable gain amplifiers (ASIC) are used as part of the recording setup. The circuit gain and balance is set by the timing of microcontroller generated clock signals. Measured results are presented which confirm that improved common-mode rejection is achieved compared to a single differential amplifier in the presence of input network imbalance. Practical measured examples further validate gain control suitable for biopotential recording and power-line rejection for wearable ECG and EMG recording. The prototype front-end consumes 318 μW including amplifiers and microcontroller.

  15. Robust Model Predictive Control of a Nonlinear System with Known Scheduling Variable and Uncertain Gain

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

    2012-01-01

    Robust model predictive control (RMPC) of a class of nonlinear systems is considered in this paper. We will use Linear Parameter Varying (LPV) model of the nonlinear system. By taking the advantage of having future values of the scheduling variable, we will simplify state prediction. Because...... of the special structure of the problem, uncertainty is only in the B matrix (gain) of the state space model. Therefore by taking advantage of this structure, we formulate a tractable minimax optimization problem to solve robust model predictive control problem. Wind turbine is chosen as the case study and we...... choose wind speed as the scheduling variable. Wind speed is measurable ahead of the turbine, therefore the scheduling variable is known for the entire prediction horizon....

  16. Large Gain in Air Quality Compared to an Alternative Anthropogenic Emissions Scenario

    Science.gov (United States)

    Daskalakis, Nikos; Tsigaridis, Kostas; Myriokefalitakis, Stelios; Fanourgakis, George S.; Kanakidou, Maria

    2016-01-01

    During the last 30 years, significant effort has been made to improve air quality through legislation for emissions reduction. Global three-dimensional chemistrytransport simulations of atmospheric composition over the past 3 decades have been performed to estimate what the air quality levels would have been under a scenario of stagnation of anthropogenic emissions per capita as in 1980, accounting for the population increase (BA1980) or using the standard practice of neglecting it (AE1980), and how they compare to the historical changes in air quality levels. The simulations are based on assimilated meteorology to account for the yearto- year observed climate variability and on different scenarios of anthropogenic emissions of pollutants. The ACCMIP historical emissions dataset is used as the starting point. Our sensitivity simulations provide clear indications that air quality legislation and technology developments have limited the rapid increase of air pollutants. The achieved reductions in concentrations of nitrogen oxides, carbon monoxide, black carbon, and sulfate aerosols are found to be significant when comparing to both BA1980 and AE1980 simulations that neglect any measures applied for the protection of the environment. We also show the potentially large tropospheric air quality benefit from the development of cleaner technology used by the growing global population. These 30-year hindcast sensitivity simulations demonstrate that the actual benefit in air quality due to air pollution legislation and technological advances is higher than the gain calculated by a simple comparison against a constant anthropogenic emissions simulation, as is usually done. Our results also indicate that over China and India the beneficial technological advances for the air quality may have been masked by the explosive increase in local population and the disproportional increase in energy demand partially due to the globalization of the economy.

  17. Large gain in air quality compared to an alternative anthropogenic emissions scenario

    Directory of Open Access Journals (Sweden)

    N. Daskalakis

    2016-08-01

    Full Text Available During the last 30 years, significant effort has been made to improve air quality through legislation for emissions reduction. Global three-dimensional chemistry-transport simulations of atmospheric composition over the past 3 decades have been performed to estimate what the air quality levels would have been under a scenario of stagnation of anthropogenic emissions per capita as in 1980, accounting for the population increase (BA1980 or using the standard practice of neglecting it (AE1980, and how they compare to the historical changes in air quality levels. The simulations are based on assimilated meteorology to account for the year-to-year observed climate variability and on different scenarios of anthropogenic emissions of pollutants. The ACCMIP historical emissions dataset is used as the starting point. Our sensitivity simulations provide clear indications that air quality legislation and technology developments have limited the rapid increase of air pollutants. The achieved reductions in concentrations of nitrogen oxides, carbon monoxide, black carbon, and sulfate aerosols are found to be significant when comparing to both BA1980 and AE1980 simulations that neglect any measures applied for the protection of the environment. We also show the potentially large tropospheric air quality benefit from the development of cleaner technology used by the growing global population. These 30-year hindcast sensitivity simulations demonstrate that the actual benefit in air quality due to air pollution legislation and technological advances is higher than the gain calculated by a simple comparison against a constant anthropogenic emissions simulation, as is usually done. Our results also indicate that over China and India the beneficial technological advances for the air quality may have been masked by the explosive increase in local population and the disproportional increase in energy demand partially due to the globalization of the economy.

  18. Continuous-variable quantum teleportation of even and odd coherent states through varied gain channels

    Institute of Scientific and Technical Information of China (English)

    Li Ying; Zhang Jing; Zhang Jun-Xiang; Zhang Tian-Cai

    2006-01-01

    This paper has investigated quantum teleportation of even and odd coherent states in terms of the EPR entanglement states for continuous variables. It discusses the relationship between the fidelity and the entanglement of EPR states, which is characterized by the degree of squeezing and the gain of classical channels. It shows that the quality of teleporting quantum states also depends on the characteristics of the states themselves. The properties of teleporting even and odd coherent states at different intensities are investigated. The difference of teleporting two such kinds of quantum states are analysed based on the quantum distance function.

  19. Vector Control Algorithm for Electric Vehicle AC Induction Motor Based on Improved Variable Gain PID Controller

    Directory of Open Access Journals (Sweden)

    Gang Qin

    2015-01-01

    Full Text Available The acceleration performance of EV, which affects a lot of performances of EV such as start-up, overtaking, driving safety, and ride comfort, has become increasingly popular in recent researches. An improved variable gain PID control algorithm to improve the acceleration performance is proposed in this paper. The results of simulation with Matlab/Simulink demonstrate the effectiveness of the proposed algorithm through the control performance of motor velocity, motor torque, and three-phase current of motor. Moreover, it is investigated that the proposed controller is valid by comparison with the other PID controllers. Furthermore, the AC induction motor experiment set is constructed to verify the effect of proposed controller.

  20. Clinical risk factors for weight gain during psychopharmacologic treatment of depression: results from 2 large German observational studies.

    Science.gov (United States)

    Kloiber, Stefan; Domschke, Katharina; Ising, Marcus; Arolt, Volker; Baune, Bernhard T; Holsboer, Florian; Lucae, Susanne

    2015-06-01

    Weight gain during psychopharmacologic treatment has considerable impact on the clinical management of depression, treatment continuation, and risk for metabolic disorders. As no profound clinical risk factors have been identified so far, the aim of our analyses was to determine clinical risk factors associated with short-term weight development in 2 large observational psychopharmacologic treatment studies for major depression. Clinical variables at baseline (age, gender, depression psychopathology, anthropometry, disease history, and disease entity) were analyzed for association with percent change in body mass index (BMI; normal range, 18.5 to 25 kg/m(2)) during 5 weeks of naturalistic psychopharmacologic treatment in patients who had a depressive episode as single depressive episode, in the course of recurrent unipolar depression or bipolar disorder according to DSM-IV criteria. 703 patients participated in the Munich Antidepressant Response Signature (MARS) project, an ongoing study since 2002, and 214 patients participated in a study conducted at the University of Muenster from 2004 to 2006 in Germany. Lower BMI, weight-increasing side effects of medication, severity of depression, and psychotic symptoms could be identified as clinical risk factors associated with elevated weight gain during the initial treatment phase of 5 weeks in both studies. Based on these results, a composite risk score for weight gain consisting of BMI ≤ 25 kg/m(2), Hamilton Depression Rating Scale (17-item) score > 20, presence of psychotic symptoms, and administration of psychopharmacologic medication with potential weight-gaining side effects was highly discriminative for mean weight gain (F4,909 = 26.77, P = 5.14E-21) during short-term psychopharmacologic treatment. On the basis of our results, depressed patients with low to normal BMI, severe depression, or psychotic symptoms should be considered at higher risk for weight gain during acute antidepressant treatment. We introduce

  1. OFDM AF Variable Gain Relay System for the Next Generation Mobile Cellular

    Directory of Open Access Journals (Sweden)

    E. Kocan

    2012-06-01

    Full Text Available In this paper we present analytical performance evaluation of a dual-hop OFDM amplify-andforward (AF variable gain (VG relay system implementing ordered subcarrier mapping (SCM at the relay station (R, considered to be a very interesting solution for the next generation mobile cellular networks. A scenario with no direct communication between the source of information (S and destination terminal (D, with the Rayleigh fading statistics on both hops is assumed. A closed form analytical expression for the bit error rate (BER performance of the considered system with DPSK modulation is derived, while for its ergodic capacity performance, a tight upper bound expression is obtained. The accuracy of the undertaken analytical approach is confirmed through comparison with simulation results. It is shown that significant capacity enhancement can be achieved through SCM implementation at R, for all the signal-to-noise ratio (SNR values on both hops, but especially in the region of small SNRs on hops. BER analysis reveals that in the region of small and medium average SNRs on both hops BER performance may also be improved with SCM at R station.

  2. Frequency domain design of gain scheduling control for large wind systems in full-load region

    International Nuclear Information System (INIS)

    Burlibaşa, A.; Ceangă, E.

    2014-01-01

    Highlights: • A large wind energy system, operating under full-load regime, is considered. • According to its particularities in frequency domain, control law design is provided. • These particularities are influenced by the interactions of wind–tower–blade ensemble. • Control low, within gain scheduling strategy, is achieved imposing stability reserve. • Supplementary a criterion, aimed at reducing mechanical loads, is imposed. - Abstract: The paper presents the issue of power control law synthesis, in the case of a large wind system that operates under full-load regime, based on dynamic properties details in frequency domain. Solving this problem involves two phases: the establishment of a linearized model as faithfully as possible in various operating points of the full-load region, and synthesis of the power controller, considered with classic structure, taking into account frequency particularities of the obtained linearized model. Obtained linear model of the controlled process is of order 16 and encloses subsystems for tower fore-aft oscillations damping, and for drive-train torsion oscillations damping. The designed controller contains a PI component and a lag compensator for dynamic correction at high frequencies. It is known that the main features of wind system dynamics generated by the interaction of wind–tower–blade ensemble cause a gap in the gain characteristic of the model and complex conjugate zeros, which can move between right and left half-planes, depending on the average wind speed value. Consequently, for control law synthesis an interactive frequency solution is adopted. This is “transparent” in relation to particularities induced by wind–tower–blade interaction. This solution allows evaluation of the extent to which control law is affected by the subsystem for tower oscillations damping. Given the strong dependence between the model and the mean wind speed value, a gain scheduling control law is designed. At

  3. Fluorescence-enhanced optical imaging in large tissue volumes using a gain-modulated ICCD camera

    International Nuclear Information System (INIS)

    Godavarty, Anuradha; Eppstein, Margaret J; Zhang, Chaoyang; Theru, Sangeeta; Thompson, Alan B; Gurfinkel, Michael; Sevick-Muraca, Eva M

    2003-01-01

    A novel image-intensified charge-coupled device (ICCD) imaging system has been developed to perform 3D fluorescence tomographic imaging in the frequency-domain using near-infrared contrast agents. The imager is unique since it (i) employs a large tissue-mimicking phantom, which is shaped and sized to resemble a female breast and part of the extended chest-wall region, and (ii) enables rapid data acquisition in the frequency-domain by using a gain-modulated ICCD camera. Diffusion model predictions are compared to experimental measurements using two different referencing schemes under two different experimental conditions of perfect and imperfect uptake of fluorescent agent into a target. From these experimental measurements, three-dimensional images of fluorescent absorption were reconstructed using a computationally efficient variant of the approximate extended Kalman filter algorithm. The current work represents the first time that 3D fluorescence-enhanced optical tomographic reconstructions have been achieved from experimental measurements of the time-dependent light propagation on a clinically relevant breast-shaped tissue phantom using a gain-modulated ICCD camera

  4. Numerical investigation of the nonlinear dynamics of a hybrid acousto-optic Bragg cell with a variable feedback gain

    Science.gov (United States)

    Chatterjee, Monish R.; Zhou, Hao

    2014-09-01

    Since around 1979, the operation of an acousto-optic Bragg cell under positive first-order feedback via amplification and delay in the loop has been studied extensively by several groups [1-3]. In recent work, the analysis of the nonlinear dynamics (NLD) of the system was extended to include bistable maps and Lyapunov exponents, and application of the chaos for signal encryption and decryption for uniform plane waves. The present work originated with the problem of a variable photodetector aperture opening relative to the first-order light. This potentially complex problem is simplified by assuming instead a variable feedback gain ( β ~ (t)), which leads to considerably different NLD. This paper examines initially the NLD versus the (DC) bias voltage for different variable- β ~ conditions, including slow and fast rates of change of the gain with time in relation to the feedback delay. It is found that the response depends critically on the rate of rise of the feedback gain, and also that the resulting chaotic regimes are generally significantly different from those for fixed values of β ~ . We have generated constant feedback gain and the variable feedback gain (t) chaos characteristics of the hybrid A-O network. Chaos as an equivalent carrier has been used to encrypt messages for both fixed and variable β ~ . The transmitted signal is detected from the encrypted carrier using a heterodyne method, using a slave Bragg cell with matched keys to generate local chaos followed by a low pass filter and a phase inverter. Results between variable- and fixed-gain systems are compared in terms of advantages and disadvantages.

  5. Redesign of a Variable-Gain Output Feedback Longitudinal Controller Flown on the High-Alpha Research Vehicle (HARV)

    Science.gov (United States)

    Ostroff, Aaron J.

    1998-01-01

    This paper describes a redesigned longitudinal controller that flew on the High-Alpha Research Vehicle (HARV) during calendar years (CY) 1995 and 1996. Linear models are developed for both the modified controller and a baseline controller that was flown in CY 1994. The modified controller was developed with three gain sets for flight evaluation, and several linear analysis results are shown comparing the gain sets. A Neal-Smith flying qualities analysis shows that performance for the low- and medium-gain sets is near the level 1 boundary, depending upon the bandwidth assumed, whereas the high-gain set indicates a sensitivity problem. A newly developed high-alpha Bode envelope criterion indicates that the control system gains may be slightly high, even for the low-gain set. A large motion-base simulator in the United Kingdom was used to evaluate the various controllers. Desired performance, which appeared to be satisfactory for flight, was generally met with both the low- and medium-gain sets. Both the high-gain set and the baseline controller were very sensitive, and it was easy to generate pilot-induced oscillation (PIO) in some of the target-tracking maneuvers. Flight target-tracking results varied from level 1 to level 3 and from no sensitivity to PIO. These results were related to pilot technique and whether actuator rate saturation was encountered.

  6. Large Signal Circuit Model of Two-Section Gain Lever Quantum Dot Laser

    International Nuclear Information System (INIS)

    Horri Ashkan; Mirmoeini Seyedeh Zahra; Faez Rahim

    2012-01-01

    An equivalent circuit model for the design and analysis of two-section gain lever quantum dot (QD) laser is presented. This model is based on the three level rate equations with two independent carrier populations and a single longitudinal optical mode. By using the presented model, the effect of gain lever on QD laser performances is investigated. The results of simulation show that the main characteristics of laser such as threshold current, transient response, output power and modulation response are affected by differential gain ratios between the two-sections

  7. Nonlinear model-based robust control of a nuclear reactor using adaptive PIF gains and variable structure controller

    International Nuclear Information System (INIS)

    Park, Moon Ghu; Cho, Nam Zin

    1993-01-01

    A Nonlinear model-based Hybrid Controller (NHC) is developed which consists of the adaptive proportional-integral-feedforward (PIF) gains and variable structure controller. The controller has the robustness against modeling uncertainty and is applied to the trajectory tracking control of single-input, single-output nonlinear systems. The essence of the scheme is to divide the control into four different terms. Namely, the adaptive P-I-F gains and variable structure controller are used to accomplish the specific control actions by each terms. The robustness of the controller is guaranteed by the feedback of estimated uncertainty and the performance specification given by the adaptation of PIF gains using the second method of Lyapunov. The variable structure controller is incorporated to regulate the initial peak of the tracking error during the parameter adaptation is not settled yet. The newly developed NHC method is applied to the power tracking control of a nuclear reactor and the simulation results show great improvement in tracking performance compared with the conventional model-based control methods. (Author)

  8. Intelligent control for large-scale variable speed variable pitch wind turbines

    Institute of Scientific and Technical Information of China (English)

    Xinfang ZHANG; Daping XU; Yibing LIU

    2004-01-01

    Large-scale wind turbine generator systems have strong nonlinear multivariable characteristics with many uncertain factors and disturbances.Automatic control is crucial for the efficiency and reliability of wind turbines.On the basis of simplified and proper model of variable speed variable pitch wind turbines,the effective wind speed is estimated using extended Kalman filter.Intelligent control schemes proposed in the paper include two loops which operate in synchronism with each other.At below-rated wind speed,the inner loop adopts adaptive fuzzy control based on variable universe for generator torque regulation to realize maximum wind energy capture.At above-rated wind speed, a controller based on least square support vector machine is proposed to adjust pitch angle and keep rated output power.The simulation shows the effectiveness of the intelligent control.

  9. Variable Stars in Large Magellanic Cloud Globular Clusters. III. Reticulum

    Science.gov (United States)

    Kuehn, Charles A.; Dame, Kyra; Smith, Horace A.; Catelan, Márcio; Jeon, Young-Beom; Nemec, James M.; Walker, Alistair R.; Kunder, Andrea; Pritzl, Barton J.; De Lee, Nathan; Borissova, Jura

    2013-06-01

    This is the third in a series of papers studying the variable stars in old globular clusters in the Large Magellanic Cloud. The primary goal of this series is to look at how the characteristics and behavior of RR Lyrae stars in Oosterhoff-intermediate systems compare to those of their counterparts in Oosterhoff-I/II systems. In this paper we present the results of our new time-series BVI photometric study of the globular cluster Reticulum. We found a total of 32 variables stars (22 RRab, 4 RRc, and 6 RRd stars) in our field of view. We present photometric parameters and light curves for these stars. We also present physical properties, derived from Fourier analysis of light curves, for some of the RR Lyrae stars. We discuss the Oosterhoff classification of Reticulum and use our results to re-derive the distance modulus and age of the cluster. Based on observations taken with the SMARTS 1.3 m telescope operated by the SMARTS Consortium and observations taken at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

  10. Active Luminous Blue Variables in the Large Magellanic Cloud

    Energy Technology Data Exchange (ETDEWEB)

    Walborn, Nolan R. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Gamen, Roberto C.; Lajús, Eduardo Fernández [Instituto de Astrofísica de La Plata, CONICET–UNLP and Facultad de Ciencias Astronómicas y Geofísicas, UNLP, Paseo del Bosque s/n, La Plata (Argentina); Morrell, Nidia I. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Barbá, Rodolfo H. [Departamento de Física y Astronomía, Universidad de La Serena, Cisternas 1200 Norte, La Serena (Chile); Angeloni, Rodolfo, E-mail: walborn@stsci.edu, E-mail: rgamen@fcaglp.unlp.edu.ar, E-mail: eflajus@fcaglp.unlp.edu.ar, E-mail: nmorrell@lco.cl, E-mail: rbarba@dfuls.cl, E-mail: rangelon@gemini.edu [Gemini Observatory, Colina El Pino, Casilla 603, La Serena (Chile)

    2017-07-01

    We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca ii] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.

  11. Active Luminous Blue Variables in the Large Magellanic Cloud

    Science.gov (United States)

    Walborn, Nolan R.; Gamen, Roberto C.; Morrell, Nidia I.; Barbá, Rodolfo H.; Fernández Lajús, Eduardo; Angeloni, Rodolfo

    2017-07-01

    We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca II] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.

  12. Active Luminous Blue Variables in the Large Magellanic Cloud

    International Nuclear Information System (INIS)

    Walborn, Nolan R.; Gamen, Roberto C.; Lajús, Eduardo Fernández; Morrell, Nidia I.; Barbá, Rodolfo H.; Angeloni, Rodolfo

    2017-01-01

    We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca ii] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.

  13. Variability in large-scale wind power generation

    DEFF Research Database (Denmark)

    Kiviluoma, Juha; Holttinen, Hannele; Weir, David

    2016-01-01

    The paper demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics include probability distribution for different ramp durations, seasonal and diurnal variability and low net ...... with well-dispersed wind power. Copyright © 2015 John Wiley & Sons, Ltd....

  14. Prediction of the Chemoreflex Gain by Common Clinical Variables in Heart Failure.

    Directory of Open Access Journals (Sweden)

    Gianluca Mirizzi

    Full Text Available Peripheral and central chemoreflex sensitivity, assessed by the hypoxic or hypercapnic ventilatory response (HVR and HCVR, respectively, is enhanced in heart failure (HF patients, is involved in the pathophysiology of the disease, and is under investigation as a potential therapeutic target. Chemoreflex sensitivity assessment is however demanding and, therefore, not easily applicable in the clinical setting. We aimed at evaluating whether common clinical variables, broadly obtained by routine clinical and instrumental evaluation, could predict increased HVR and HCVR.191 patients with systolic HF (left ventricular ejection fraction--LVEF--<50% underwent chemoreflex assessment by rebreathing technique to assess HVR and HCVR. All patients underwent clinical and neurohormonal evaluation, comprising: echocardiogram, cardiopulmonary exercise test (CPET, daytime cardiorespiratory monitoring for breathing pattern evaluation. Regarding HVR, multivariate penalized logistic regression, Bayesian Model Averaging (BMA logistic regression and random forest analysis identified, as predictors, the presence of periodic breathing and increased slope of the relation between ventilation and carbon dioxide production (VE/VCO2 during exercise. Again, the above-mentioned statistical tools identified as HCVR predictors plasma levels of N-terminal fragment of proBNP and VE/VCO2 slope.In HF patients, the simple assessment of breathing pattern, alongside with ventilatory efficiency during exercise and natriuretic peptides levels identifies a subset of patients presenting with increased chemoreflex sensitivity to either hypoxia or hypercapnia.

  15. Job gains and losses at large and small firms during the Great Recession

    OpenAIRE

    Juan M. Sánchez; Lowell R. Ricketts

    2012-01-01

    Conventional wisdom says that employment at small firms declines more than employment at large firms during recessions. However, that doesn’t seem to have been the case during the Great Recession of 2007-09.

  16. Intermodal parametric gain of degenerate four wave mixing in large mode area hybrid photonic crystal fibers

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Lægsgaard, Jesper; Alkeskjold, Thomas Tanggaard

    2013-01-01

    Intermodal degenerate four wave mixing (FWM) is investigated numerically in large mode area hybrid photonic crystal fibers. The dispersion is controlled independently of core size, and thus allows for power scaling of the FWM process.......Intermodal degenerate four wave mixing (FWM) is investigated numerically in large mode area hybrid photonic crystal fibers. The dispersion is controlled independently of core size, and thus allows for power scaling of the FWM process....

  17. North Atlantic explosive cyclones and large scale atmospheric variability modes

    Science.gov (United States)

    Liberato, Margarida L. R.

    2015-04-01

    Extreme windstorms are one of the major natural catastrophes in the extratropics, one of the most costly natural hazards in Europe and are responsible for substantial economic damages and even fatalities. During the last decades Europe witnessed major damage from winter storms such as Lothar (December 1999), Kyrill (January 2007), Klaus (January 2009), Xynthia (February 2010), Gong (January 2013) and Stephanie (February 2014) which exhibited uncommon characteristics. In fact, most of these storms crossed the Atlantic in direction of Europe experiencing an explosive development at unusual lower latitudes along the edge of the dominant North Atlantic storm track and reaching Iberia with an uncommon intensity (Liberato et al., 2011; 2013; Liberato 2014). Results show that the explosive cyclogenesis process of most of these storms at such low latitudes is driven by: (i) the southerly displacement of a very strong polar jet stream; and (ii) the presence of an atmospheric river (AR), that is, by a (sub)tropical moisture export over the western and central (sub)tropical Atlantic which converges into the cyclogenesis region and then moves along with the storm towards Iberia. Previous studies have pointed to a link between the North Atlantic Oscillation (NAO) and intense European windstorms. On the other hand, the NAO exerts a decisive control on the average latitudinal location of the jet stream over the North Atlantic basin (Woollings et al. 2010). In this work the link between North Atlantic explosive cyclogenesis, atmospheric rivers and large scale atmospheric variability modes is reviewed and discussed. Liberato MLR (2014) The 19 January 2013 windstorm over the north Atlantic: Large-scale dynamics and impacts on Iberia. Weather and Climate Extremes, 5-6, 16-28. doi: 10.1016/j.wace.2014.06.002 Liberato MRL, Pinto JG, Trigo IF, Trigo RM. (2011) Klaus - an exceptional winter storm over Northern Iberia and Southern France. Weather 66:330-334. doi:10.1002/wea.755 Liberato

  18. Isocurvature modes and Baryon Acoustic Oscillations II: gains from combining CMB and Large Scale Structure

    International Nuclear Information System (INIS)

    Carbone, Carmelita; Mangilli, Anna; Verde, Licia

    2011-01-01

    We consider cosmological parameters estimation in the presence of a non-zero isocurvature contribution in the primordial perturbations. A previous analysis showed that even a tiny amount of isocurvature perturbation, if not accounted for, could affect standard rulers calibration from Cosmic Microwave Background observations such as those provided by the Planck mission, affect Baryon Acoustic Oscillations interpretation, and introduce biases in the recovered dark energy properties that are larger than forecasted statistical errors from future surveys. Extending on this work, here we adopt a general fiducial cosmology which includes a varying dark energy equation of state parameter and curvature. Beside Baryon Acoustic Oscillations measurements, we include the information from the shape of the galaxy power spectrum and consider a joint analysis of a Planck-like Cosmic Microwave Background probe and a future, space-based, Large Scale Structure probe not too dissimilar from recently proposed surveys. We find that this allows one to break the degeneracies that affect the Cosmic Microwave Background and Baryon Acoustic Oscillations combination. As a result, most of the cosmological parameter systematic biases arising from an incorrect assumption on the isocurvature fraction parameter f iso , become negligible with respect to the statistical errors. We find that the Cosmic Microwave Background and Large Scale Structure combination gives a statistical error σ(f iso ) ∼ 0.008, even when curvature and a varying dark energy equation of state are included, which is smaller that the error obtained from Cosmic Microwave Background alone when flatness and cosmological constant are assumed. These results confirm the synergy and complementarity between Cosmic Microwave Background and Large Scale Structure, and the great potential of future and planned galaxy surveys

  19. Experience Gained From the Construction, Test and Operation of the Large 4-T CMS Coil

    CERN Document Server

    Hervé, A; Curé, B; Fabbricatore, P; Gaddi, A; Kircher, F; Sgobba, S

    2008-01-01

    The 4-T, 6-m free bore CMS solenoid has been successfully tested, operated and mapped at CERN during the autumn of 2006; R&D studies started in 1993 and the construction proper in 1997. The main parameters of this 100 MUS$ project (including yoke) were then considered beyond what was thought possible, as the total stored magnetic energy reaches 2.6 GJ for a specific magnetic energy density exceeding 11 kJ/kg of cold mass. During this period, the international design and construction team had to make several important technical choices, in particular mechanical, to maximize the chances of reaching the nominal induction of 4 Tesla. The paper will review these choices in the light of what is presently known and examine if better solutions would be possible today for constructing a new large high-field thin solenoid for a future detector magnet.

  20. Association between gestational weight gain according to body mass index and postpartum weight in a large cohort of Danish women.

    Science.gov (United States)

    Rode, Line; Kjærgaard, Hanne; Ottesen, Bent; Damm, Peter; Hegaard, Hanne K

    2012-02-01

    Our aim was to investigate the association between gestational weight gain (GWG) and postpartum weight retention (PWR) in pre-pregnancy underweight, normal weight, overweight or obese women, with emphasis on the American Institute of Medicine (IOM) recommendations. We performed secondary analyses on data based on questionnaires from 1,898 women from the "Smoke-free Newborn Study" conducted 1996-1999 at Hvidovre Hospital, Denmark. Relationship between GWG and PWR was examined according to BMI as a continuous variable and in four groups. Association between PWR and GWG according to IOM recommendations was tested by linear regression analysis and the association between PWR ≥ 5 kg (11 lbs) and GWG by logistic regression analysis. Mean GWG and mean PWR were constant for all BMI units until 26-27 kg/m(2). After this cut-off mean GWG and mean PWR decreased with increasing BMI. Nearly 40% of normal weight, 60% of overweight and 50% of obese women gained more than recommended during pregnancy. For normal weight and overweight women with GWG above recommendations the OR of gaining ≥ 5 kg (11 lbs) 1-year postpartum was 2.8 (95% CI 2.0-4.0) and 2.8 (95% CI 1.3-6.2, respectively) compared to women with GWG within recommendations. GWG above IOM recommendations significantly increases normal weight, overweight and obese women's risk of retaining weight 1 year after delivery. Health personnel face a challenge in prenatal counseling as 40-60% of these women gain more weight than recommended for their BMI. As GWG is potentially modifiable, our study should be followed by intervention studies focusing on GW.

  1. Hydrometeorological variability on a large french catchment and its relation to large-scale circulation across temporal scales

    Science.gov (United States)

    Massei, Nicolas; Dieppois, Bastien; Fritier, Nicolas; Laignel, Benoit; Debret, Maxime; Lavers, David; Hannah, David

    2015-04-01

    In the present context of global changes, considerable efforts have been deployed by the hydrological scientific community to improve our understanding of the impacts of climate fluctuations on water resources. Both observational and modeling studies have been extensively employed to characterize hydrological changes and trends, assess the impact of climate variability or provide future scenarios of water resources. In the aim of a better understanding of hydrological changes, it is of crucial importance to determine how and to what extent trends and long-term oscillations detectable in hydrological variables are linked to global climate oscillations. In this work, we develop an approach associating large-scale/local-scale correlation, enmpirical statistical downscaling and wavelet multiresolution decomposition of monthly precipitation and streamflow over the Seine river watershed, and the North Atlantic sea level pressure (SLP) in order to gain additional insights on the atmospheric patterns associated with the regional hydrology. We hypothesized that: i) atmospheric patterns may change according to the different temporal wavelengths defining the variability of the signals; and ii) definition of those hydrological/circulation relationships for each temporal wavelength may improve the determination of large-scale predictors of local variations. The results showed that the large-scale/local-scale links were not necessarily constant according to time-scale (i.e. for the different frequencies characterizing the signals), resulting in changing spatial patterns across scales. This was then taken into account by developing an empirical statistical downscaling (ESD) modeling approach which integrated discrete wavelet multiresolution analysis for reconstructing local hydrometeorological processes (predictand : precipitation and streamflow on the Seine river catchment) based on a large-scale predictor (SLP over the Euro-Atlantic sector) on a monthly time-step. This approach

  2. Enhancing the efficiency of constrained dual-hop variable-gain AF relaying under nakagami-m fading

    KAUST Repository

    Zafar, Ammar

    2014-07-01

    This paper studies power allocation for performance constrained dual-hop variable-gain amplify-and-forward (AF) relay networks in Nakagami- $m$ fading. In this context, the performance constraint is formulated as a constraint on the end-to-end signal-to-noise-ratio (SNR) and the overall power consumed is minimized while maintaining this constraint. This problem is considered under two different assumptions of the available channel state information (CSI) at the relays, namely full CSI at the relays and partial CSI at the relays. In addition to the power minimization problem, we also consider the end-to-end SNR maximization problem under a total power constraint for the partial CSI case. We provide closed-form solutions for all the problems which are easy to implement except in two cases, namely selective relaying with partial CSI for power minimization and SNR maximization, where we give the solution in the form of a one-variable equation which can be solved efficiently. Numerical results are then provided to characterize the performance of the proposed power allocation algorithms considering the effects of channel parameters and CSI availability. © 2014 IEEE.

  3. Uni- and multi-variable modelling of flood losses: experiences gained from the Secchia river inundation event.

    Science.gov (United States)

    Carisi, Francesca; Domeneghetti, Alessio; Kreibich, Heidi; Schröter, Kai; Castellarin, Attilio

    2017-04-01

    Flood risk is function of flood hazard and vulnerability, therefore its accurate assessment depends on a reliable quantification of both factors. The scientific literature proposes a number of objective and reliable methods for assessing flood hazard, yet it highlights a limited understanding of the fundamental damage processes. Loss modelling is associated with large uncertainty which is, among other factors, due to a lack of standard procedures; for instance, flood losses are often estimated based on damage models derived in completely different contexts (i.e. different countries or geographical regions) without checking its applicability, or by considering only one explanatory variable (i.e. typically water depth). We consider the Secchia river flood event of January 2014, when a sudden levee-breach caused the inundation of nearly 200 km2 in Northern Italy. In the aftermath of this event, local authorities collected flood loss data, together with additional information on affected private households and industrial activities (e.g. buildings surface and economic value, number of company's employees and others). Based on these data we implemented and compared a quadratic-regression damage function, with water depth as the only explanatory variable, and a multi-variable model that combines multiple regression trees and considers several explanatory variables (i.e. bagging decision trees). Our results show the importance of data collection revealing that (1) a simple quadratic regression damage function based on empirical data from the study area can be significantly more accurate than literature damage-models derived for a different context and (2) multi-variable modelling may outperform the uni-variable approach, yet it is more difficult to develop and apply due to a much higher demand of detailed data.

  4. Influence of climate variability on large rivers runoff

    Directory of Open Access Journals (Sweden)

    B. Nurtaev

    2015-06-01

    Full Text Available In accordance with IPCC Report the influence of climate change on the water cycle will increase hydrologic variability by means of changing of precipitation patterns, melting of ice and change of runoff. Precipitation has increased in high northern latitudes and decreased in southern latitudes. This study presents an analysis of river runoffs trends in different climatic zones of the world in condition of climate change.

  5. Joubert syndrome: large clinical variability and a unique neuroimaging aspect

    International Nuclear Information System (INIS)

    Leao, Emilia Katiane Embirucu; Lima, Marcilia Martyn; Kok, Fernando; Parizotto, Juliana; Maia Junior, Otacilio de Oliveira

    2010-01-01

    Joubert syndrome (JS) is an autosomal recessive inherited disorder characterized by hypotonia, cerebellar vermis hypoplasia, ocular abnormalities (e.g. pigmentary retinopathy, oculomotor apraxia and nystagmus), renal cysts and hepatic fibrosis. Respiratory abnormalities, as apnoea and hyperpnoea, may be present, as well as mental retardation. At least seven JS loci have been determined and five genes identified. Herein, we report five children, belonging to independent families, with JS: they shared the same typical MRI abnormality, known as molar tooth sign, but had an otherwise quite variable phenotype, regarding mostly their cognitive performance, visual abilities and extra-neurological compromise. (author)

  6. Joubert syndrome: large clinical variability and a unique neuroimaging aspect

    Energy Technology Data Exchange (ETDEWEB)

    Leao, Emilia Katiane Embirucu; Lima, Marcilia Martyn; Kok, Fernando; Parizotto, Juliana [University of Sao Paulo (USP), Sao Paulo, SP (Brazil). Clinical Hospital. Dept. of Child Neurology; Maia Junior, Otacilio de Oliveira [University of Sao Paulo (USP), Sao Paulo, SP (Brazil). Clinical Hospital. Dept. of Child Ophthalmology

    2010-04-15

    Joubert syndrome (JS) is an autosomal recessive inherited disorder characterized by hypotonia, cerebellar vermis hypoplasia, ocular abnormalities (e.g. pigmentary retinopathy, oculomotor apraxia and nystagmus), renal cysts and hepatic fibrosis. Respiratory abnormalities, as apnoea and hyperpnoea, may be present, as well as mental retardation. At least seven JS loci have been determined and five genes identified. Herein, we report five children, belonging to independent families, with JS: they shared the same typical MRI abnormality, known as molar tooth sign, but had an otherwise quite variable phenotype, regarding mostly their cognitive performance, visual abilities and extra-neurological compromise. (author)

  7. Nouveau déphaseur variable analogique large-bande

    OpenAIRE

    Khoder , Khaled; Le Roy , Marc; Pérennec , André

    2013-01-01

    National audience; Dans cet article, une nouvelle topologie de déphaseur analogique variable est proposée. Elle est obtenue en inter-combinant un déphaseur de Schiffman et un déphaseur passe-tout mixte distribué/localisé. Ce déphaseur compact présente l'avantage d'une forte agilité en phase pour une variation limitée de la capacité de la varicap. Les mesures du dispositif réalisé en technologie hybride microruban confirme une variation continue du déphasage jusqu'à 180° pour un circuit à une ...

  8. Sustained fitness gains and variability in fitness trajectories in the long-term evolution experiment with Escherichia coli

    Science.gov (United States)

    Lenski, Richard E.; Wiser, Michael J.; Ribeck, Noah; Blount, Zachary D.; Nahum, Joshua R.; Morris, J. Jeffrey; Zaman, Luis; Turner, Caroline B.; Wade, Brian D.; Maddamsetti, Rohan; Burmeister, Alita R.; Baird, Elizabeth J.; Bundy, Jay; Grant, Nkrumah A.; Card, Kyle J.; Rowles, Maia; Weatherspoon, Kiyana; Papoulis, Spiridon E.; Sullivan, Rachel; Clark, Colleen; Mulka, Joseph S.; Hajela, Neerja

    2015-01-01

    Many populations live in environments subject to frequent biotic and abiotic changes. Nonetheless, it is interesting to ask whether an evolving population's mean fitness can increase indefinitely, and potentially without any limit, even in a constant environment. A recent study showed that fitness trajectories of Escherichia coli populations over 50 000 generations were better described by a power-law model than by a hyperbolic model. According to the power-law model, the rate of fitness gain declines over time but fitness has no upper limit, whereas the hyperbolic model implies a hard limit. Here, we examine whether the previously estimated power-law model predicts the fitness trajectory for an additional 10 000 generations. To that end, we conducted more than 1100 new competitive fitness assays. Consistent with the previous study, the power-law model fits the new data better than the hyperbolic model. We also analysed the variability in fitness among populations, finding subtle, but significant, heterogeneity in mean fitness. Some, but not all, of this variation reflects differences in mutation rate that evolved over time. Taken together, our results imply that both adaptation and divergence can continue indefinitely—or at least for a long time—even in a constant environment. PMID:26674951

  9. Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training.

    Science.gov (United States)

    West, Daniel W D; Phillips, Stuart M

    2012-07-01

    The purpose of this study was to investigate associations between acute exercise-induced hormone responses and adaptations to high intensity resistance training in a large cohort (n = 56) of young men. Acute post-exercise serum growth hormone (GH), free testosterone (fT), insulin-like growth factor (IGF-1) and cortisol responses were determined following an acute intense leg resistance exercise routine at the midpoint of a 12-week resistance exercise training study. Acute hormonal responses were correlated with gains in lean body mass (LBM), muscle fibre cross-sectional area (CSA) and leg press strength. There were no significant correlations between the exercise-induced elevations (area under the curve-AUC) of GH, fT and IGF-1 and gains in LBM or leg press strength. Significant correlations were found for cortisol, usually assumed to be a hormone indicative of catabolic drive, AUC with change in LBM (r = 0.29, P training-induced changes in fibre CSA and LBM (cortisol only), but not with changes in strength.

  10. A variable geometry truss manipulator for positioning large payloads

    International Nuclear Information System (INIS)

    Stoughton, R.S.; Tucker, J.C.; Horner, C.G.

    1995-02-01

    A major thrust within the Department of Energy's (DOE) Decontamination and Dismantling (D ampersand D) Robotics program is the development of a Selective Equipment Removal System (SERS). SERS will consist of a mobile vehicle, a Dual-Arm Work Module (DAWM), and a deployment manipulator capable of extending the DAWM up to 6.096m (20) from the vehicle. The DAWM, built by RedZone Robotics, includes two Schilling Titan II manipulators, a unique five degree-of-freedom (DOF) module for positioning/orienting the two Schilling arms, and a massive steel backplane to maintain structural rigidity. Together with its payload, the DAWM weighs about 975 kg (2150 pounds). In order to accurately position the DAWM, the Pacific Northwest Laboratory (PNL) together with the National Aeronautics and Space Administration's Langley Research Center (NASA LARC) are developing a deployment manipulator, which includes two double-octahedral Variable Geometry Truss (VGT) modules connected with a static truss section. The entire SERS system (Figure 1) will include the mobile vehicle, a 2-DOF base actuation system (waist rotate and pitch) with an output link approximately 2.134m (7) in length, the VGT system and the DAWM. The VGT system (Figure 2) consists of a 1.067m (42) diameter (∼1.346m (53) long) base VGT, which mounts to the end of the output link of the base actuation system, a 1.524m (60) long static truss section which tapers from 1.067m (42) diameter at its base to 0.8128m (32) diameter at the end, and a 0.8128m (32) diameter (∼1.0922m (43) long) tip VGT to which the DAWM is mounted. The stiffness of the VGT system is such that with the base VGT mounted to a rigid base and the VGT system oriented horizontally (worst case), the static deflection of the DAWM together with full payload will be less than 0.0254m

  11. Molecular dynamics based enhanced sampling of collective variables with very large time steps

    Science.gov (United States)

    Chen, Pei-Yang; Tuckerman, Mark E.

    2018-01-01

    Enhanced sampling techniques that target a set of collective variables and that use molecular dynamics as the driving engine have seen widespread application in the computational molecular sciences as a means to explore the free-energy landscapes of complex systems. The use of molecular dynamics as the fundamental driver of the sampling requires the introduction of a time step whose magnitude is limited by the fastest motions in a system. While standard multiple time-stepping methods allow larger time steps to be employed for the slower and computationally more expensive forces, the maximum achievable increase in time step is limited by resonance phenomena, which inextricably couple fast and slow motions. Recently, we introduced deterministic and stochastic resonance-free multiple time step algorithms for molecular dynamics that solve this resonance problem and allow ten- to twenty-fold gains in the large time step compared to standard multiple time step algorithms [P. Minary et al., Phys. Rev. Lett. 93, 150201 (2004); B. Leimkuhler et al., Mol. Phys. 111, 3579-3594 (2013)]. These methods are based on the imposition of isokinetic constraints that couple the physical system to Nosé-Hoover chains or Nosé-Hoover Langevin schemes. In this paper, we show how to adapt these methods for collective variable-based enhanced sampling techniques, specifically adiabatic free-energy dynamics/temperature-accelerated molecular dynamics, unified free-energy dynamics, and by extension, metadynamics, thus allowing simulations employing these methods to employ similarly very large time steps. The combination of resonance-free multiple time step integrators with free-energy-based enhanced sampling significantly improves the efficiency of conformational exploration.

  12. Energy-efficient relay selection and optimal power allocation for performance-constrained dual-hop variable-gain AF relaying

    KAUST Repository

    Zafar, Ammar; Radaydeh, Redha Mahmoud Mesleh; Chen, Yunfei; Alouini, Mohamed-Slim

    2013-01-01

    This paper investigates the energy-efficiency enhancement of a variable-gain dual-hop amplify-and-forward (AF) relay network utilizing selective relaying. The objective is to minimize the total consumed power while keeping the end-to-end signal

  13. Valuation of large variable annuity portfolios: Monte Carlo simulation and synthetic datasets

    Directory of Open Access Journals (Sweden)

    Gan Guojun

    2017-12-01

    Full Text Available Metamodeling techniques have recently been proposed to address the computational issues related to the valuation of large portfolios of variable annuity contracts. However, it is extremely diffcult, if not impossible, for researchers to obtain real datasets frominsurance companies in order to test their metamodeling techniques on such real datasets and publish the results in academic journals. To facilitate the development and dissemination of research related to the effcient valuation of large variable annuity portfolios, this paper creates a large synthetic portfolio of variable annuity contracts based on the properties of real portfolios of variable annuities and implements a simple Monte Carlo simulation engine for valuing the synthetic portfolio. In addition, this paper presents fair market values and Greeks for the synthetic portfolio of variable annuity contracts that are important quantities for managing the financial risks associated with variable annuities. The resulting datasets can be used by researchers to test and compare the performance of various metamodeling techniques.

  14. Effectiveness of Variable-Gain Kalman Filter Based on Angle Error Calculated from Acceleration Signals in Lower Limb Angle Measurement with Inertial Sensors

    Science.gov (United States)

    Watanabe, Takashi

    2013-01-01

    The wearable sensor system developed by our group, which measured lower limb angles using Kalman-filtering-based method, was suggested to be useful in evaluation of gait function for rehabilitation support. However, it was expected to reduce variations of measurement errors. In this paper, a variable-Kalman-gain method based on angle error that was calculated from acceleration signals was proposed to improve measurement accuracy. The proposed method was tested comparing to fixed-gain Kalman filter and a variable-Kalman-gain method that was based on acceleration magnitude used in previous studies. First, in angle measurement in treadmill walking, the proposed method measured lower limb angles with the highest measurement accuracy and improved significantly foot inclination angle measurement, while it improved slightly shank and thigh inclination angles. The variable-gain method based on acceleration magnitude was not effective for our Kalman filter system. Then, in angle measurement of a rigid body model, it was shown that the proposed method had measurement accuracy similar to or higher than results seen in other studies that used markers of camera-based motion measurement system fixing on a rigid plate together with a sensor or on the sensor directly. The proposed method was found to be effective in angle measurement with inertial sensors. PMID:24282442

  15. Investigation with automatic ultrasonic equipment to trace flaws in a large test piece, and experience gained in carrying out inspections

    International Nuclear Information System (INIS)

    Lindner, J.P.

    1975-01-01

    Based on the FRG codes providing guide lines for the Reactor Safety Commission regarding the size and location of flaws to be detected during in-service inspections, investigations were carried out into the possibility of detecting defects in thick-walled reactor pressure vessel components with the aid of ultrasonic inspection systems. A large test rig was used and, in a similar manner to the in-service inspections on a reactor, the tests were carried out with remote-controlled, automatically guided inspection equipment. For this purpose, a test specimen weighing about 10 tons was produced and provided with two weld seams having a large number of artificial defects. Essential parameters for the various reflectors in the test specimen were the size, location, angle and roughness or structure of the reflecting surfaces. As it is known that austenitic cladding has a considerable influence on flaw detection, the tests were undertaken first without cladding and then with cladding. A manipulator was designed for automatic remote-controlled inspection with which the inspection system travels on a meandering route over the area to be inspected. The inspection system employed was of the same type as the one used for baseline tests during external inspections of reactor vessel walls with parallel surfaces. Digital data collection was by a magnetic tape recorder designed to store both the data of the ultrasonic inspection system as well as the allied position data. The data stored on the tape are evaluated with electronic data processing programmes especially developed for this purpose. These programmes allow locally coherent indication patterns to be prepared, thus simplifying the interpretation of the data obtained. The author initially describes the equipment with the aid of which the studies were undertaken. A detailed discussion is then presented on the design of the test specimen and the inspection systems employed. Following this, the results obtained are explained and

  16. Strong Laws of Large Numbers for Arrays of Rowwise NA and LNQD Random Variables

    Directory of Open Access Journals (Sweden)

    Jiangfeng Wang

    2011-01-01

    Full Text Available Some strong laws of large numbers and strong convergence properties for arrays of rowwise negatively associated and linearly negative quadrant dependent random variables are obtained. The results obtained not only generalize the result of Hu and Taylor to negatively associated and linearly negative quadrant dependent random variables, but also improve it.

  17. Generation of 103 fs mode-locked pulses by a gain linewidth-variable Nd,Y:CaF2 disordered crystal.

    Science.gov (United States)

    Qin, Z P; Xie, G Q; Ma, J; Ge, W Y; Yuan, P; Qian, L J; Su, L B; Jiang, D P; Ma, F K; Zhang, Q; Cao, Y X; Xu, J

    2014-04-01

    We have demonstrated a diode-pumped passively mode-locked femtosecond Nd,Y:CaF2 disordered crystal laser for the first time to our knowledge. By choosing appropriate Y-doping concentration, a broad fluorescence linewidth of 31 nm has been obtained from the gain linewidth-variable Nd,Y:CaF2 crystal. With the Nd,Y:CaF2 disordered crystal as gain medium, the mode-locked laser generated pulses with pulse duration as short as 103 fs, average output power of 89 mW, and repetition rate of 100 MHz. To our best knowledge, this is the shortest pulse generated from Nd-doped crystal lasers so far. The research results show that the Nd,Y:CaF2 disordered crystal will be a potential alternative as gain medium of repetitive chirped pulse amplification for high-peak-power lasers.

  18. Experience gained in the process of the variable mass heat flow control implemented in the district heat supply system of the city of Gyor

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, F.; Milanovich, L.; Lelek, J.; Kekk, I. [District Heating LTD. of Gyor (Hungary)

    1996-11-01

    The district heating system of the city of Gyor is fed from a hot water boiler plant. The total heat demand for 23,000 residential homes and several public facilities is 260 MW. The variable mass flow control was implemented in 1991 through 1992. Design, preparatory job and the majority of implementation was carried out without external involvement. The paper presents historical background and brief project presentation which is followed by comparative presentation of the variable mass flow control and constant mass flow control. This comparative survey has been conducted on the basis of operating data for 1993 and those for 1988. In the conclusion the gained experience is summarized.

  19. Association Between Gestational Weight Gain According to Body Mass Index and Postpartum Weight in a Large Cohort of Danish Women

    DEFF Research Database (Denmark)

    Rode, Line; Kjærgaard, Hanne; Ottesen, Bent

    2012-01-01

    weight, 60% of overweight and 50% of obese women gained more than recommended during pregnancy. For normal weight and overweight women with GWG above recommendations the OR of gaining = 5 kg (11 lbs) 1-year postpartum was 2.8 (95% CI 2.0-4.0) and 2.8 (95% CI 1.3-6.2, respectively) compared to women...... with GWG within recommendations. GWG above IOM recommendations significantly increases normal weight, overweight and obese women's risk of retaining weight 1 year after delivery. Health personnel face a challenge in prenatal counseling as 40-60% of these women gain more weight than recommended...

  20. Evidence for large temperature fluctuations in quasar accretion disks from spectral variability

    Energy Technology Data Exchange (ETDEWEB)

    Ruan, John J.; Anderson, Scott F.; Agol, Eric [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Dexter, Jason, E-mail: jruan@astro.washington.edu [Departments of Physics and Astronomy, University of California, Berkeley, CA 94720 (United States)

    2014-03-10

    The well-known bluer-when-brighter trend observed in quasar variability is a signature of the complex processes in the accretion disk and can be a probe of the quasar variability mechanism. Using a sample of 604 variable quasars with repeat spectra in the Sloan Digital Sky Survey-I/II (SDSS), we construct difference spectra to investigate the physical causes of this bluer-when-brighter trend. The continuum of our composite difference spectrum is well fit by a power law, with a spectral index in excellent agreement with previous results. We measure the spectral variability relative to the underlying spectra of the quasars, which is independent of any extinction, and compare to model predictions. We show that our SDSS spectral variability results cannot be produced by global accretion rate fluctuations in a thin disk alone. However, we find that a simple model of an inhomogeneous disk with localized temperature fluctuations will produce power-law spectral variability over optical wavelengths. We show that the inhomogeneous disk will provide good fits to our observed spectral variability if the disk has large temperature fluctuations in many independently varying zones, in excellent agreement with independent constraints from quasar microlensing disk sizes, their strong UV spectral continuum, and single-band variability amplitudes. Our results provide an independent constraint on quasar variability models and add to the mounting evidence that quasar accretion disks have large localized temperature fluctuations.

  1. Characterizing Temperature Variability and Associated Large Scale Meteorological Patterns Across South America

    Science.gov (United States)

    Detzer, J.; Loikith, P. C.; Mechoso, C. R.; Barkhordarian, A.; Lee, H.

    2017-12-01

    South America's climate varies considerably owing to its large geographic range and diverse topographical features. Spanning the tropics to the mid-latitudes and from high peaks to tropical rainforest, the continent experiences an array of climate and weather patterns. Due to this considerable spatial extent, assessing temperature variability at the continent scale is particularly challenging. It is well documented in the literature that temperatures have been increasing across portions of South America in recent decades, and while there have been many studies that have focused on precipitation variability and change, temperature has received less scientific attention. Therefore, a more thorough understanding of the drivers of temperature variability is critical for interpreting future change. First, k-means cluster analysis is used to identify four primary modes of temperature variability across the continent, stratified by season. Next, composites of large scale meteorological patterns (LSMPs) are calculated for months assigned to each cluster. Initial results suggest that LSMPs, defined using meteorological variables such as sea level pressure (SLP), geopotential height, and wind, are able to identify synoptic scale mechanisms important for driving temperature variability at the monthly scale. Some LSMPs indicate a relationship with known recurrent modes of climate variability. For example, composites of geopotential height suggest that the Southern Annular Mode is an important, but not necessarily dominant, component of temperature variability over southern South America. This work will be extended to assess the drivers of temperature extremes across South America.

  2. Comparing Pleasure and Pain: The Fundamental Mathematical Equivalence of Reward Gain and Shock Reduction under Variable Interval Schedules

    Science.gov (United States)

    Mallpress, Dave E. W.; Fawcett, Tim W.; McNamara, John M.; Houston, Alasdair I.

    2012-01-01

    The relationship between positive and negative reinforcement and the symmetry of Thorndike's law of effect are unresolved issues in operant psychology. Here we show that, for a given pattern of responding on variable interval (VI) schedules with the same programmed rate of food rewards (positive reinforcement VI) or electric shocks (negative…

  3. A Variable Stiffness Analysis Model for Large Complex Thin-Walled Guide Rail

    Directory of Open Access Journals (Sweden)

    Wang Xiaolong

    2016-01-01

    Full Text Available Large complex thin-walled guide rail has complicated structure and no uniform low rigidity. The traditional cutting simulations are time consuming due to huge computation especially in large workpiece. To solve these problems, a more efficient variable stiffness analysis model has been propose, which can obtain quantitative stiffness value of the machining surface. Applying simulate cutting force in sampling points using finite element analysis software ABAQUS, the single direction variable stiffness rule can be obtained. The variable stiffness matrix has been propose by analyzing multi-directions coupling variable stiffness rule. Combining with the three direction cutting force value, the reasonability of existing processing parameters can be verified and the optimized cutting parameters can be designed.

  4. Response of ENSO amplitude to global warming in CESM large ensemble: uncertainty due to internal variability

    Science.gov (United States)

    Zheng, Xiao-Tong; Hui, Chang; Yeh, Sang-Wook

    2018-06-01

    El Niño-Southern Oscillation (ENSO) is the dominant mode of variability in the coupled ocean-atmospheric system. Future projections of ENSO change under global warming are highly uncertain among models. In this study, the effect of internal variability on ENSO amplitude change in future climate projections is investigated based on a 40-member ensemble from the Community Earth System Model Large Ensemble (CESM-LE) project. A large uncertainty is identified among ensemble members due to internal variability. The inter-member diversity is associated with a zonal dipole pattern of sea surface temperature (SST) change in the mean along the equator, which is similar to the second empirical orthogonal function (EOF) mode of tropical Pacific decadal variability (TPDV) in the unforced control simulation. The uncertainty in CESM-LE is comparable in magnitude to that among models of the Coupled Model Intercomparison Project phase 5 (CMIP5), suggesting the contribution of internal variability to the intermodel uncertainty in ENSO amplitude change. However, the causations between changes in ENSO amplitude and the mean state are distinct between CESM-LE and CMIP5 ensemble. The CESM-LE results indicate that a large ensemble of 15 members is needed to separate the relative contributions to ENSO amplitude change over the twenty-first century between forced response and internal variability.

  5. 5.2 GHz variable-gain amplifier and power amplifier driver for WLAN IEEE 802.11a transmitter front-end

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xuelian; Yan Jun; Shi Yin [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Foster, Dai Fa, E-mail: xlzhang@semi.ac.c [Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849-5201 (United States)

    2009-01-15

    A 5.2 GHz variable-gain amplifier (VGA) and a power amplifier (PA) driver are designed for WLAN IEEE 802.11a monolithic RFIC. The VGA and the PA driver are implemented in a 50 GHz 0.35 mum SiGe BiCMOS technology and occupy 1.12 x 1.25 mm{sup 2} die area. The VGA with effective temperature compensation is controlled by 5 bits and has a gain range of 34 dB. The PA driver with tuned loads utilizes a differential input, single-ended output topology, and the tuned loads resonate at 5.2 GHz. The maximum overall gain of the VGA and the PA driver is 29 dB with the output third-order intercept point (OIP3) of 11 dBm. The gain drift over the temperature varying from -30 to 85 deg. C converges within +-3 dB. The total current consumption is 45 mA under a 2.85 V power supply.

  6. The Independent Importance of Pre-pregnancy Weight and Gestational Weight Gain for the Prevention of Large-for Gestational Age Brazilian Newborns.

    Science.gov (United States)

    Mastroeni, Marco F; Czarnobay, Sandra A; Kroll, Caroline; Figueirêdo, Katherinne B W; Mastroeni, Silmara S B S; Silva, Jean C; Khan, Mohammad K A; Loehr, Sarah; Veugelers, Paul J

    2017-04-01

    Objectives To study the independent effect of pre-pregnancy weight, gestational weight gain (GWG), and other important risk factors on newborn birth weight. Methods Baseline data of 435 adult women and their singletons born between January and February 2012 at a public hospital in Brazil were used. Logistic regression was applied to determine the independent importance of pre-pregnancy weight and GWG for large for gestational age (LGA) newborns. Results Among all mothers, 37.9 % were overweight and obese before pregnancy and 45.3 % experienced excessive GWG. Among the newborns, 24.4 % were classified as LGA. Univariate analysis showed an association of family income, GWG, pre-pregnancy BMI and excessive GWG with LGA newborns. Smoking before and during pregnancy was associated with a decreased likelihood of giving birth to an LGA newborn compared to mothers who did not smoke. After adjustment for confounding variables, age at birth of first child, GWG, HbA1c and pre-pregnancy weight-GWG were significant and independent determinants of giving birth to an LGA newborn. Mothers with pre-pregnancy overweight and excessive GWG were more likely to deliver an LGA newborn (OR 2.54, P weight and experienced adequate GWG. Conclusions for Practice Age at first birth of child, GWG, HbA1c and pre-pregnancy overweight combined with excessive GWG are independent determinants of LGA newborns. The results of this study suggest that both primary prevention of overweight in women of childbearing age and management of GWG may be important strategies to reduce the number of LGA newborns and, consequently, the long-term public health burden of obesity.

  7. European Wintertime Windstorms and its Links to Large-Scale Variability Modes

    Science.gov (United States)

    Befort, D. J.; Wild, S.; Walz, M. A.; Knight, J. R.; Lockwood, J. F.; Thornton, H. E.; Hermanson, L.; Bett, P.; Weisheimer, A.; Leckebusch, G. C.

    2017-12-01

    Winter storms associated with extreme wind speeds and heavy precipitation are the most costly natural hazard in several European countries. Improved understanding and seasonal forecast skill of winter storms will thus help society, policy-makers and (re-) insurance industry to be better prepared for such events. We firstly assess the ability to represent extra-tropical windstorms over the Northern Hemisphere of three seasonal forecast ensemble suites: ECMWF System3, ECMWF System4 and GloSea5. Our results show significant skill for inter-annual variability of windstorm frequency over parts of Europe in two of these forecast suites (ECMWF-S4 and GloSea5) indicating the potential use of current seasonal forecast systems. In a regression model we further derive windstorm variability using the forecasted NAO from the seasonal model suites thus estimating the suitability of the NAO as the only predictor. We find that the NAO as the main large-scale mode over Europe can explain some of the achieved skill and is therefore an important source of variability in the seasonal models. However, our results show that the regression model fails to reproduce the skill level of the directly forecast windstorm frequency over large areas of central Europe. This suggests that the seasonal models also capture other sources of variability/predictability of windstorms than the NAO. In order to investigate which other large-scale variability modes steer the interannual variability of windstorms we develop a statistical model using a Poisson GLM. We find that the Scandinavian Pattern (SCA) in fact explains a larger amount of variability for Central Europe during the 20th century than the NAO. This statistical model is able to skilfully reproduce the interannual variability of windstorm frequency especially for the British Isles and Central Europe with correlations up to 0.8.

  8. Test-retest reliability of trunk motor variability measured by large-array surface electromyography.

    Science.gov (United States)

    Abboud, Jacques; Nougarou, François; Loranger, Michel; Descarreaux, Martin

    2015-01-01

    The objective of this study was to evaluate the test-retest reliability of the trunk muscle activity distribution in asymptomatic participants during muscle fatigue using large-array surface electromyography (EMG). Trunk muscle activity distribution was evaluated twice, with 3 to 4 days between them, in 27 asymptomatic volunteers using large-array surface EMG. Motor variability, assessed with 2 different variables (the centroid coordinates of the root mean square map and the dispersion variable), was evaluated during a low back muscle fatigue task. Test-retest reliability of muscle activity distribution was obtained using Pearson correlation coefficients. A shift in the distribution of EMG amplitude toward the lateral-caudal region of the lumbar erector spinae induced by muscle fatigue was observed. Moderate to very strong correlations were found between both sessions in the last 3 phases of the fatigue task for both motor variability variables, whereas weak to moderate correlations were found in the first phases of the fatigue task only for the dispersion variable. These findings show that, in asymptomatic participants, patterns of EMG activity are less reliable in initial stages of muscle fatigue, whereas later stages are characterized by highly reliable patterns of EMG activity. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  9. Combined Influence of Gestational Weight Gain and Estimated Fetal Weight on Risk Assessment for Small- or Large-for-Gestational-Age Birth Weight: A Prospective Cohort Study.

    Science.gov (United States)

    Pugh, Sarah J; Hinkle, Stefanie N; Kim, Sungduk; Albert, Paul S; Newman, Roger; Grobman, William A; Wing, Deborah A; Grantz, Katherine L

    2018-04-01

    To evaluate the frequency with which gestational weight gain and estimated fetal weight do not track across gestation and to assess the risk of small-for-gestational-age (SGA) and large-for-gestational-age (LGA) birth weight as a function of tracking. This study included a pregnancy cohort (2009-2013) of 2438 women from 4 racial/ethnic groups in the United States. We calculated race- and trimester-specific gestational weight gain and estimated fetal weight z scores. The prevalence of how often gestational weight gain and estimated fetal weight did not or did directly track was examined by grouping z scores into measure-specific categories (1 SD) and then examining 2-measure combinations. Trimester-specific relative risks for SGA and LGA births were estimated with a gestational weight gain and estimated fetal weight z score interaction. We estimated coefficients for selected gestational weight gain and estimated fetal weight values (-1 SD, 0 SD, and +1 SD) compared with the referent of 0 SD for both measures. Small and large for gestational age were calculated as birth weight below the 10th and at or above the 90th percentiles, respectively. Gestational weight gain and estimated fetal weight were within 1 SD 55.5%, 51.5%, and 48.2% of the time in the first, second, and third trimesters, respectively. There was no significant interaction between gestational weight gain and estimated fetal weight on the risk of SGA in the first and second trimesters (interaction term P = .48; P = .79). In the third trimester, there was a significant interaction (P = .002), resulting in a 71% (95% confidence interval, 1.45-2.02) increased risk of SGA when estimated fetal weight was low and gestational weight gain was high. These relationships were similar for the risk of LGA. Deviations in either measure, even in the presence of average gestational weight gain or estimated fetal weight, still suggest an increased risk of SGA and LGA. © 2017 by the American Institute of

  10. Large Variability in the Diversity of Physiologically Complex Surgical Procedures Exists Nationwide Among All Hospitals Including Among Large Teaching Hospitals.

    Science.gov (United States)

    Dexter, Franklin; Epstein, Richard H; Thenuwara, Kokila; Lubarsky, David A

    2017-11-22

    Multiple previous studies have shown that having a large diversity of procedures has a substantial impact on quality management of hospital surgical suites. At hospitals with substantial diversity, unless sophisticated statistical methods suitable for rare events are used, anesthesiologists working in surgical suites will have inaccurate predictions of surgical blood usage, case durations, cost accounting and price transparency, times remaining in late running cases, and use of intraoperative equipment. What is unknown is whether large diversity is a feature of only a few very unique set of hospitals nationwide (eg, the largest hospitals in each state or province). The 2013 United States Nationwide Readmissions Database was used to study heterogeneity among 1981 hospitals in their diversities of physiologically complex surgical procedures (ie, the procedure codes). The diversity of surgical procedures performed at each hospital was quantified using a summary measure, the number of different physiologically complex surgical procedures commonly performed at the hospital (ie, 1/Herfindahl). A total of 53.9% of all hospitals commonly performed 3-fold larger diversity (ie, >30 commonly performed physiologically complex procedures). Larger hospitals had greater diversity than the small- and medium-sized hospitals (P 30 procedures (lower 99% CL, 71.9% of hospitals). However, there was considerable variability among the large teaching hospitals in their diversity (interquartile range of the numbers of commonly performed physiologically complex procedures = 19.3; lower 99% CL, 12.8 procedures). The diversity of procedures represents a substantive differentiator among hospitals. Thus, the usefulness of statistical methods for operating room management should be expected to be heterogeneous among hospitals. Our results also show that "large teaching hospital" alone is an insufficient description for accurate prediction of the extent to which a hospital sustains the

  11. Cooperative Coevolution with Formula-Based Variable Grouping for Large-Scale Global Optimization.

    Science.gov (United States)

    Wang, Yuping; Liu, Haiyan; Wei, Fei; Zong, Tingting; Li, Xiaodong

    2017-08-09

    For a large-scale global optimization (LSGO) problem, divide-and-conquer is usually considered an effective strategy to decompose the problem into smaller subproblems, each of which can then be solved individually. Among these decomposition methods, variable grouping is shown to be promising in recent years. Existing variable grouping methods usually assume the problem to be black-box (i.e., assuming that an analytical model of the objective function is unknown), and they attempt to learn appropriate variable grouping that would allow for a better decomposition of the problem. In such cases, these variable grouping methods do not make a direct use of the formula of the objective function. However, it can be argued that many real-world problems are white-box problems, that is, the formulas of objective functions are often known a priori. These formulas of the objective functions provide rich information which can then be used to design an effective variable group method. In this article, a formula-based grouping strategy (FBG) for white-box problems is first proposed. It groups variables directly via the formula of an objective function which usually consists of a finite number of operations (i.e., four arithmetic operations "[Formula: see text]", "[Formula: see text]", "[Formula: see text]", "[Formula: see text]" and composite operations of basic elementary functions). In FBG, the operations are classified into two classes: one resulting in nonseparable variables, and the other resulting in separable variables. In FBG, variables can be automatically grouped into a suitable number of non-interacting subcomponents, with variables in each subcomponent being interdependent. FBG can easily be applied to any white-box problem and can be integrated into a cooperative coevolution framework. Based on FBG, a novel cooperative coevolution algorithm with formula-based variable grouping (so-called CCF) is proposed in this article for decomposing a large-scale white-box problem

  12. Ytterbium-doped large-mode-area photonic crystal fiber amplifier with gain shaping for use at long wavelengths

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Alkeskjold, Thomas T.; Poli, Federica

    2012-01-01

    A large-mode-area Ytterbium-doped photonic crystal fiber amplifier with efficient suppression of amplified spontaneous emission is presented. The fiber cladding consists of a hexagonal lattice of air holes, where three rows are replaced with circular high-index inclusions. Seven missing air holes...

  13. Weight gain after bariatric surgery as a result of a large gastric stoma: endotherapy with sodium morrhuate may prevent the need for surgical revision.

    Science.gov (United States)

    Catalano, Marc F; Rudic, Goran; Anderson, Alfred J; Chua, Thomas Y

    2007-08-01

    Obesity affects more than 30% of the U.S. population and is associated with the development of life-threatening complications. Numerous therapeutic approaches to the problem have been advocated, including low-calorie diets, anoretic drugs, behavior modifications, and exercise therapy. The only treatment proven to be effective in the long-term management of morbid obesity is surgical intervention. Complications of bariatric surgery include stomal stenosis and/or ulcer and stomal dilation (secondary to overeating). The latter complication can result in a gain of previously lost weight. To determine the effect of endoscopic injection by using a sclerosant (sodium morrhuate) to induce stomal stenosis in patients who present with stomal dilatation complicated by weight gain. Bariatric patients with a large gastric stoma were treated with sodium morrhuate stomal injection. Diameters of the stoma were followed at repeat endoscopy. Weight loss at scheduled clinic visits were compared with pretherapy weights. Twenty-eight patients (10 men, 18 women; age range, 27-58 years), after bariatric surgery with GI bypass, were referred with weight gain after initial weight loss. Weight gain was believed to be the result of a large gastric stoma. Treatment included injection of sodium morrhuate (1-2 mL circumferentially) surrounding the stoma. A total of 1 to 3 injection sessions were performed in an attempt to achieve a stoma diameter of 1.2 cm or smaller. Treatment success was defined as a decrease of stoma size to weight loss >or=75% of the weight the patient gained after establishing a steady state post bariatric surgery weight. A total of 2.3 injection sessions were performed. Successful endotherapy was achieved in 18 of 28 patients (64%). One patient developed symptoms of stomal stenosis, which required 2 separate balloon dilating sessions. No other complications were encountered. Retrospective case series. Endoscopic injection of sodium morrhuate surrounding the dilated

  14. VARIABLE STARS IN LARGE MAGELLANIC CLOUD GLOBULAR CLUSTERS. II. NGC 1786

    International Nuclear Information System (INIS)

    Kuehn, Charles A.; Smith, Horace A.; De Lee, Nathan; Catelan, Márcio; Pritzl, Barton J.; Borissova, Jura

    2012-01-01

    This is the second in a series of papers studying the variable stars in Large Magellanic Cloud globular clusters. The primary goal of this series is to study how RR Lyrae stars in Oosterhoff-intermediate systems compare to their counterparts in Oosterhoff I/II systems. In this paper, we present the results of our new time-series B–V photometric study of the globular cluster NGC 1786. A total of 65 variable stars were identified in our field of view. These variables include 53 RR Lyraes (27 RRab, 18 RRc, and 8 RRd), 3 classical Cepheids, 1 Type II Cepheid, 1 Anomalous Cepheid, 2 eclipsing binaries, 3 Delta Scuti/SX Phoenicis variables, and 2 variables of undetermined type. Photometric parameters for these variables are presented. We present physical properties for some of the RR Lyrae stars, derived from Fourier analysis of their light curves. We discuss several different indicators of Oosterhoff type which indicate that the Oosterhoff classification of NGC 1786 is not as clear cut as what is seen in most globular clusters.

  15. Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training

    OpenAIRE

    West, Daniel W. D.; Phillips, Stuart M.

    2011-01-01

    The purpose of this study was to investigate associations between acute exercise-induced hormone responses and adaptations to high intensity resistance training in a large cohort (n = 56) of young men. Acute post-exercise serum growth hormone (GH), free testosterone (fT), insulin-like growth factor (IGF-1) and cortisol responses were determined following an acute intense leg resistance exercise routine at the midpoint of a 12-week resistance exercise training study. Acute hormonal responses w...

  16. Development of sub-nanosecond, high gain structures for time-of-flight ring imaging in large area detectors

    International Nuclear Information System (INIS)

    Wetstein, Matthew

    2011-01-01

    Microchannel plate photomultiplier tubes (MCPs) are compact, imaging detectors, capable of micron-level spatial imaging and timing measurements with resolutions below 10 ps. Conventional fabrication methods are too expensive for making MCPs in the quantities and sizes necessary for typical HEP applications, such as time-of-flight ring-imaging Cherenkov detectors (TOF-RICH) or water Cherenkov-based neutrino experiments. The Large Area Picosecond Photodetector Collaboration (LAPPD) is developing new, commercializable methods to fabricate 20 cm 2 thin planar MCPs at costs comparable to those of traditional photo-multiplier tubes. Transmission-line readout with waveform sampling on both ends of each line allows the efficient coverage of large areas while maintaining excellent time and space resolution. Rather than fabricating channel plates from active, high secondary electron emission materials, we produce plates from passive substrates, and coat them using atomic layer deposition (ALD), a well established industrial batch process. In addition to possible reductions in cost and conditioning time, this allows greater control to optimize the composition of active materials for performance. We present details of the MCP fabrication method, preliminary results from testing and characterization facilities, and possible HEP applications.

  17. Energy-efficient relay selection and optimal power allocation for performance-constrained dual-hop variable-gain AF relaying

    KAUST Repository

    Zafar, Ammar

    2013-12-01

    This paper investigates the energy-efficiency enhancement of a variable-gain dual-hop amplify-and-forward (AF) relay network utilizing selective relaying. The objective is to minimize the total consumed power while keeping the end-to-end signal-to-noise-ratio (SNR) above a certain peak value and satisfying the peak power constraints at the source and relay nodes. To achieve this objective, an optimal relay selection and power allocation strategy is derived by solving the power minimization problem. Numerical results show that the derived optimal strategy enhances the energy-efficiency as compared to a benchmark scheme in which both the source and the selected relay transmit at peak power. © 2013 IEEE.

  18. Variable Stars in Large Magellanic Cloud Globular Clusters. II. NGC 1786

    Science.gov (United States)

    Kuehn, Charles A.; Smith, Horace A.; Catelan, Márcio; Pritzl, Barton J.; De Lee, Nathan; Borissova, Jura

    2012-12-01

    This is the second in a series of papers studying the variable stars in Large Magellanic Cloud globular clusters. The primary goal of this series is to study how RR Lyrae stars in Oosterhoff-intermediate systems compare to their counterparts in Oosterhoff I/II systems. In this paper, we present the results of our new time-series B-V photometric study of the globular cluster NGC 1786. A total of 65 variable stars were identified in our field of view. These variables include 53 RR Lyraes (27 RRab, 18 RRc, and 8 RRd), 3 classical Cepheids, 1 Type II Cepheid, 1 Anomalous Cepheid, 2 eclipsing binaries, 3 Delta Scuti/SX Phoenicis variables, and 2 variables of undetermined type. Photometric parameters for these variables are presented. We present physical properties for some of the RR Lyrae stars, derived from Fourier analysis of their light curves. We discuss several different indicators of Oosterhoff type which indicate that the Oosterhoff classification of NGC 1786 is not as clear cut as what is seen in most globular clusters. Based on observations taken with the SMARTS 1.3 m telescope operated by the SMARTS Consortium and observations taken at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

  19. Large behavioral variability of motile E. coli revealed in 3D spatial exploration

    Science.gov (United States)

    Figueroa-Morales, N.; Darnige, T.; Martinez, V.; Douarche, C.; Soto, R.; Lindner, A.; Clement, E.

    2017-11-01

    Bacterial motility determines the spatio-temporal structure of microbial communities, controls infection spreading and the microbiota organization in guts or in soils. Quantitative modeling of chemotaxis and statistical descriptions of active bacterial suspensions currently rely on the classical vision of a run-and-tumble strategy exploited by bacteria to explore their environment. Here we report a large behavioral variability of wild-type E. coli, revealed in their three-dimensional trajectories. We found a broad distribution of run times for individual cells, in stark contrast with the accepted vision of a single characteristic time. We relate our results to the slow fluctuations of a signaling protein which triggers the switching of the flagellar motor reversal responsible for tumbles. We demonstrate that such a large distribution of run times introduces measurement biases in most practical situations. These results reconcile a notorious conundrum between observations of run times and motor switching statistics. Our study implies that the statistical modeling of transport properties and of the chemotactic response of bacterial populations need to be profoundly revised to correctly account for the large variability of motility features.

  20. The influence of Seychelles Dome on the large scale Tropical Variability

    Science.gov (United States)

    Manola, Iris; Selten, Frank; Hazeleger, Wilco

    2013-04-01

    The Seychelles Dome (SD) is the thermocline ridge just South of the equator in the Western Indian Ocean basin. It is characterized by strong atmospheric convection and a shallow thermocline and is associated with large intraseasonal convection and SST variability (Harrison and Vecchi 2001). The SD is influenced by surface and subsurface processes, such as air-sea fluxes, Ekman upwelling from wind stress curl, ocean dynamics (vertical mixing) and oceanic Rossby waves from southeastern Indian Ocean. The favoring season for a strong SD is the boreal winter, where the thermocline is most shallow. Then the southeasterly trade winds converge with the northwesterly monsoonal winds over the intertropical convergence zone and cause cyclonic wind stress curl that drives Ekman divergence and a ridging of the thermocline. It is found that the subseasonal and interranual variability of the SD is influenced by large scale events, such as the Indian Ocean Dipole (IOD), the ENSO and the Madden-Julian Oscillation (MJO) (Tozuka et al., 2010, Lloyd and Vecchi, 2010). The SD is enhanced by cooling events in the Western Indian Ocean and easterly winds that raise the thermocline and increase the upwelling. This can be associated with a strong Walker circulation, like negative IOD conditions or La Nina-like conditions. So far the studies focus on the origins of the SD variability, but the influence of the SD itself on regional or large scale climate is largely unknown. In this study we focus on the influence of the SD variations on the large scale tropical circulation. We analyze the covariance of the SD variations and the tropical circulation in a 200 year control imulation of the climate model EC-EARTH and perform idealized SST forced simulations to study the character of the atmospheric response and its relation to ENSO, IOD and MJO. References -Harrison, D. E. and G. A. Vecchi, 2001: January 1999 Indian Ocean cooling event. Geophys. Res. Lett., 28, 3717-3720. -Lloyd, I. D., and G. A

  1. Storm-tracks interannual variability and large-scale climate modes

    Science.gov (United States)

    Liberato, Margarida L. R.; Trigo, Isabel F.; Trigo, Ricardo M.

    2013-04-01

    In this study we focus on the interannual variability and observed changes in northern hemisphere mid-latitude storm-tracks and relate them to large scale atmospheric circulation variability modes. Extratropical storminess, cyclones dominant paths, frequency and intensity have long been the object of climatological studies. The analysis of storm characteristics and historical trends presented here is based on the cyclone detecting and tracking algorithm first developed for the Mediterranean region (Trigo et al. 1999) and recently extended to a larger Euro-Atlantic region (Trigo 2006). The objective methodology, which identifies and follows individual lows as minima in SLP fields, fulfilling a set of conditions regarding the central pressure and the pressure gradient, is applied to the northern hemisphere 6-hourly geopotential data at 1000 hPa from the 20th Century Reanalyses (20CRv2) project and from reanalyses datasets provided by the European Centre for Medium-Range Weather Forecasts (ECMWF): ERA-40 and ERA Interim reanalyses. First, we assess the interannual variability and cyclone frequency trends for each of the datasets, for the 20th century and for the period between 1958 and 2002 using the highest spatial resolution available (1.125° x 1.125°) from the ERA-40 data. Results show that winter variability of storm paths, cyclone frequency and travel times is in agreement with the reported variability in a number of large-scale climate patterns (including the North Atlantic Oscillation, the East Atlantic Pattern and the Scandinavian Pattern). In addition, three storm-track databases are built spanning the common available extended winter seasons from October 1979 to March 2002. Although relatively short, this common period allows a comparison of systems represented in reanalyses datasets with distinct horizontal resolutions. This exercise is mostly focused on the key areas of cyclogenesis and cyclolysis and main cyclone characteristics over the northern

  2. Data on respiratory variables in critically ill patients with acute respiratory failure placed on proportional assist ventilation with load adjustable gain factors (PAV+

    Directory of Open Access Journals (Sweden)

    Dimitris Georgopoulos

    2016-09-01

    Full Text Available The data show respiratory variables in 108 critically ill patients with acute respiratory failure placed on proportional assist ventilation with load adjustable gain factors (PAV+ after at least 36 h on passive mechanical ventilation. PAV+ was continued for 48 h until the patients met pre-defined criteria either for switching to controlled modes or for breathing without ventilator assistance. Data during passive mechanical ventilation and during PAV+ are reported. Data are acquired from the whole population, as well as from patients with and without acute respiratory distress syndrome. The reported variables are tidal volume, driving pressure (ΔP, the difference between static end-inspiratory plateau pressure and positive end-expiratory airway pressure, respiratory system compliance and resistance, and arterial blood gasses. The data are supplemental to our original research article, which described individual ΔP in these patients and examined how it related to ΔP when the same patients were ventilated with passive mechanical ventilation using the currently accepted lung-protective strategy “Driving pressure during assisted mechanical ventilation. Is it controlled by patient brain?” [1]. Keywords: Tidal volume, Compliance, Driving pressure

  3. Scheduling of power generation a large-scale mixed-variable model

    CERN Document Server

    Prékopa, András; Strazicky, Beáta; Deák, István; Hoffer, János; Németh, Ágoston; Potecz, Béla

    2014-01-01

    The book contains description of a real life application of modern mathematical optimization tools in an important problem solution for power networks. The objective is the modelling and calculation of optimal daily scheduling of power generation, by thermal power plants,  to satisfy all demands at minimum cost, in such a way that the  generation and transmission capacities as well as the demands at the nodes of the system appear in an integrated form. The physical parameters of the network are also taken into account. The obtained large-scale mixed variable problem is relaxed in a smart, practical way, to allow for fast numerical solution of the problem.

  4. Variable-Speed Power-Turbine for the Large Civil Tilt Rotor

    Science.gov (United States)

    Suchezky, Mark; Cruzen, G. Scott

    2012-01-01

    Turbine design concepts were studied for application to a large civil tiltrotor transport aircraft. The concepts addressed the need for high turbine efficiency across the broad 2:1 turbine operating speed range representative of the notional mission for the aircraft. The study focused on tailoring basic turbine aerodynamic design design parameters to avoid the need for complex, heavy, and expensive variable geometry features. The results of the study showed that good turbine performance can be achieved across the design speed range if the design focuses on tailoring the aerodynamics for good tolerance to large swings in incidence, as opposed to optimizing for best performance at the long range cruise design point. A rig design configuration and program plan are suggested for a dedicated experiment to validate the proposed approach.

  5. R Aquarii - the large-scale optical nebula and the Mira variable position

    International Nuclear Information System (INIS)

    Michalitsianos, A.G.; Oliversen, R.J.; Hollis, J.M.; Kafatos, M.; Crull, H.E.

    1988-01-01

    The R Aquarii symbiotic star system is surrounded by a large-scale optical nebula. Observations of the nebular forbidden O III structure are presented and its morphological significance are discussed in context with previously observed small-scale radio-continuum features, which may be related. It is suggested that a precessing accretion disk may explain the global features of both the large-scale optical emission and the small-scale radio emission. Moreover, an accurate position has been determined of the system's Mira, which suggests that a recent theoretical model, yielding an egg-shaped central H II region for symbiotic systems with certain physical parameters, may apply to R Aquarii. The optical position of the 387 d period Mira variable is consistent with previous findings in the radio, that SiO maser emission is far removed from the Mira photosphere. 25 references

  6. Assessing large-scale weekly cycles in meteorological variables: a review

    Directory of Open Access Journals (Sweden)

    A. Sanchez-Lorenzo

    2012-07-01

    Full Text Available Several studies have claimed to have found significant weekly cycles of meteorological variables appearing over large domains, which can hardly be related to urban effects exclusively. Nevertheless, there is still an ongoing scientific debate whether these large-scale weekly cycles exist or not, and some other studies fail to reproduce them with statistical significance. In addition to the lack of the positive proof for the existence of these cycles, their possible physical explanations have been controversially discussed during the last years. In this work we review the main results about this topic published during the recent two decades, including a summary of the existence or non-existence of significant weekly weather cycles across different regions of the world, mainly over the US, Europe and Asia. In addition, some shortcomings of common statistical methods for analyzing weekly cycles are listed. Finally, a brief summary of supposed causes of the weekly cycles, focusing on the aerosol-cloud-radiation interactions and their impact on meteorological variables as a result of the weekly cycles of anthropogenic activities, and possible directions for future research, is presented.

  7. Characterisation of silent and active genes for a variable large protein of Borrelia recurrentis

    Directory of Open Access Journals (Sweden)

    Scragg Ian G

    2002-10-01

    Full Text Available Abstract Background We report the characterisation of the variable large protein (vlp gene expressed by clinical isolate A1 of Borrelia recurrentis; the agent of the life-threatening disease louse-borne relapsing fever. Methods The major vlp protein of this isolate was characterised and a DNA probe created. Use of this together with standard molecular methods was used to determine the location of the vlp1B. recurrentis A1 gene in both this and other isolates. Results This isolate was found to carry silent and expressed copies of the vlp1B. recurrentis A1 gene on plasmids of 54 kbp and 24 kbp respectively, whereas a different isolate, A17, had only the silent vlp1B. recurrentis A17 on a 54 kbp plasmid. Silent and expressed vlp1 have identical mature protein coding regions but have different 5' regions, both containing different potential lipoprotein leader sequences. Only one form of vlp1 is transcribed in the A1 isolate of B. recurrentis, yet both 5' upstream sequences of this vlp1 gene possess features of bacterial promoters. Conclusion Taken together these results suggest that antigenic variation in B. recurrentis may result from recombination of variable large and small protein genes at the junction between lipoprotein leader sequence and mature protein coding region. However, this hypothetical model needs to be validated by further identification of expressed and silent variant protein genes in other B. recurrentis isolates.

  8. Discovery of Fast, Large-amplitude Optical Variability of V648 Car (=SS73-17)

    Science.gov (United States)

    Angeloni, R.; Di Mille, F.; Ferreira Lopes, C. E.; Masetti, N.

    2012-09-01

    We report on the discovery of large-amplitude flickering from V648 Car (= SS73-17), a poorly studied object listed among the very few hard X-ray-emitting symbiotic stars. We performed millimagnitude precision optical photometry with the Swope Telescope at the Las Campanas Observatory, Chile, and found that V648 Car shows large U-band variability over timescales of minutes. To our knowledge, it exhibits some of the largest flickering of a symbiotic star ever reported. Our finding supports the hypothesis that symbiotic white dwarfs producing hard X-rays are predominantly powered by accretion, rather than quasi-steady nuclear burning, and have masses close to the Chandrasekhar limit. No significant periodicity is evident from the flickering light curve. The All Sky Automated Survey long-term V light curve suggests the presence of a tidally distorted giant accreting via Roche lobe overflow, and a binary period of ~520 days. On the basis of the outstanding physical properties of V648 Car as hinted at by its fast and long-term optical variability, as well as by its nature as a hard X-ray emitter, we therefore call for simultaneous follow-up observations in different bands, ideally combined with time-resolved optical spectroscopy.

  9. DISCOVERY OF FAST, LARGE-AMPLITUDE OPTICAL VARIABILITY OF V648 Car (=SS73-17)

    International Nuclear Information System (INIS)

    Angeloni, R.; Di Mille, F.; Ferreira Lopes, C. E.; Masetti, N.

    2012-01-01

    We report on the discovery of large-amplitude flickering from V648 Car (= SS73-17), a poorly studied object listed among the very few hard X-ray-emitting symbiotic stars. We performed millimagnitude precision optical photometry with the Swope Telescope at the Las Campanas Observatory, Chile, and found that V648 Car shows large U-band variability over timescales of minutes. To our knowledge, it exhibits some of the largest flickering of a symbiotic star ever reported. Our finding supports the hypothesis that symbiotic white dwarfs producing hard X-rays are predominantly powered by accretion, rather than quasi-steady nuclear burning, and have masses close to the Chandrasekhar limit. No significant periodicity is evident from the flickering light curve. The All Sky Automated Survey long-term V light curve suggests the presence of a tidally distorted giant accreting via Roche lobe overflow, and a binary period of ∼520 days. On the basis of the outstanding physical properties of V648 Car as hinted at by its fast and long-term optical variability, as well as by its nature as a hard X-ray emitter, we therefore call for simultaneous follow-up observations in different bands, ideally combined with time-resolved optical spectroscopy.

  10. Large strain variable stiffness composites for shear deformations with applications to morphing aircraft skins

    Science.gov (United States)

    McKnight, G. P.; Henry, C. P.

    2008-03-01

    Morphing or reconfigurable structures potentially allow for previously unattainable vehicle performance by permitting several optimized structures to be achieved using a single platform. The key to enabling this technology in applications such as aircraft wings, nozzles, and control surfaces, are new engineered materials which can achieve the necessary deformations but limit losses in parasitic actuation mass and structural efficiency (stiffness/weight). These materials should exhibit precise control of deformation properties and provide high stiffness when exercised through large deformations. In this work, we build upon previous efforts in segmented reinforcement variable stiffness composites employing shape memory polymers to create prototype hybrid composite materials that combine the benefits of cellular materials with those of discontinuous reinforcement composites. These composites help overcome two key challenges for shearing wing skins: the resistance to out of plane buckling from actuation induced shear deformation, and resistance to membrane deflections resulting from distributed aerodynamic pressure loading. We designed, fabricated, and tested composite materials intended for shear deformation and address out of plane deflections in variable area wing skins. Our designs are based on the kinematic engineering of reinforcement platelets such that desired microstructural kinematics is achieved through prescribed boundary conditions. We achieve this kinematic control by etching sheets of metallic reinforcement into regular patterns of platelets and connecting ligaments. This kinematic engineering allows optimization of materials properties for a known deformation pathway. We use mechanical analysis and full field photogrammetry to relate local scale kinematics and strains to global deformations for both axial tension loading and shear loading with a pinned-diamond type fixture. The Poisson ratio of the kinematically engineered composite is ~3x higher than

  11. Effects of a large wildfire on vegetation structure in a variable fire mosaic.

    Science.gov (United States)

    Foster, C N; Barton, P S; Robinson, N M; MacGregor, C I; Lindenmayer, D B

    2017-12-01

    Management guidelines for many fire-prone ecosystems highlight the importance of maintaining a variable mosaic of fire histories for biodiversity conservation. Managers are encouraged to aim for fire mosaics that are temporally and spatially dynamic, include all successional states of vegetation, and also include variation in the underlying "invisible mosaic" of past fire frequencies, severities, and fire return intervals. However, establishing and maintaining variable mosaics in contemporary landscapes is subject to many challenges, one of which is deciding how the fire mosaic should be managed following the occurrence of large, unplanned wildfires. A key consideration for this decision is the extent to which the effects of previous fire history on vegetation and habitats persist after major wildfires, but this topic has rarely been investigated empirically. In this study, we tested to what extent a large wildfire interacted with previous fire history to affect the structure of forest, woodland, and heath vegetation in Booderee National Park in southeastern Australia. In 2003, a summer wildfire burned 49.5% of the park, increasing the extent of recently burned vegetation (post-fire) to more than 72% of the park area. We tracked the recovery of vegetation structure for nine years following the wildfire and found that the strength and persistence of fire effects differed substantially between vegetation types. Vegetation structure was modified by wildfire in forest, woodland, and heath vegetation, but among-site variability in vegetation structure was reduced only by severe fire in woodland vegetation. There also were persistent legacy effects of the previous fire regime on some attributes of vegetation structure including forest ground and understorey cover, and woodland midstorey and overstorey cover. For example, woodland midstorey cover was greater on sites with higher fire frequency, irrespective of the severity of the 2003 wildfire. Our results show that even

  12. Investigating the Variability in Cumulus Cloud Number as a Function of Subdomain Size and Organization using large-domain LES

    Science.gov (United States)

    Neggers, R.

    2017-12-01

    Recent advances in supercomputing have introduced a "grey zone" in the representation of cumulus convection in general circulation models, in which this process is partially resolved. Cumulus parameterizations need to be made scale-aware and scale-adaptive to be able to conceptually and practically deal with this situation. A potential way forward are schemes formulated in terms of discretized Cloud Size Densities, or CSDs. Advantages include i) the introduction of scale-awareness at the foundation of the scheme, and ii) the possibility to apply size-filtering of parameterized convective transport and clouds. The CSD is a new variable that requires closure; this concerns its shape, its range, but also variability in cloud number that can appear due to i) subsampling effects and ii) organization in a cloud field. The goal of this study is to gain insight by means of sub-domain analyses of various large-domain LES realizations of cumulus cloud populations. For a series of three-dimensional snapshots, each with a different degree of organization, the cloud size distribution is calculated in all subdomains, for a range of subdomain sizes. The standard deviation of the number of clouds of a certain size is found to decrease with the subdomain size, following a powerlaw scaling corresponding to an inverse-linear dependence. Cloud number variability also increases with cloud size; this reflects that subsampling affects the largest clouds first, due to their typically larger neighbor spacing. Rewriting this dependence in terms of two dimensionless groups, by dividing by cloud number and cloud size respectively, yields a data collapse. Organization in the cloud field is found to act on top of this primary dependence, by enhancing the cloud number variability at the smaller sizes. This behavior reflects that small clouds start to "live" on top of larger structures such as cold pools, favoring or inhibiting their formation (as illustrated by the attached figure of cloud mask

  13. RECOVERY OF LARGE ANGULAR SCALE CMB POLARIZATION FOR INSTRUMENTS EMPLOYING VARIABLE-DELAY POLARIZATION MODULATORS

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N. J.; Marriage, T. A.; Appel, J. W.; Bennett, C. L.; Eimer, J.; Essinger-Hileman, T.; Harrington, K.; Rostem, K.; Watts, D. J. [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 (United States); Chuss, D. T. [Department of Physics, Villanova University, 800 E Lancaster, Villanova, PA 19085 (United States); Wollack, E. J.; Fixsen, D. J.; Moseley, S. H.; Switzer, E. R., E-mail: Nathan.J.Miller@nasa.gov [Observational Cosmology Laboratory, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-02-20

    Variable-delay Polarization Modulators (VPMs) are currently being implemented in experiments designed to measure the polarization of the cosmic microwave background on large angular scales because of their capability for providing rapid, front-end polarization modulation and control over systematic errors. Despite the advantages provided by the VPM, it is important to identify and mitigate any time-varying effects that leak into the synchronously modulated component of the signal. In this paper, the effect of emission from a 300 K VPM on the system performance is considered and addressed. Though instrument design can greatly reduce the influence of modulated VPM emission, some residual modulated signal is expected. VPM emission is treated in the presence of rotational misalignments and temperature variation. Simulations of time-ordered data are used to evaluate the effect of these residual errors on the power spectrum. The analysis and modeling in this paper guides experimentalists on the critical aspects of observations using VPMs as front-end modulators. By implementing the characterizations and controls as described, front-end VPM modulation can be very powerful for mitigating 1/f noise in large angular scale polarimetric surveys. None of the systematic errors studied fundamentally limit the detection and characterization of B-modes on large scales for a tensor-to-scalar ratio of r = 0.01. Indeed, r < 0.01 is achievable with commensurately improved characterizations and controls.

  14. Challenges in the automated classification of variable stars in large databases

    Directory of Open Access Journals (Sweden)

    Graham Matthew

    2017-01-01

    Full Text Available With ever-increasing numbers of astrophysical transient surveys, new facilities and archives of astronomical time series, time domain astronomy is emerging as a mainstream discipline. However, the sheer volume of data alone - hundreds of observations for hundreds of millions of sources – necessitates advanced statistical and machine learning methodologies for scientific discovery: characterization, categorization, and classification. Whilst these techniques are slowly entering the astronomer’s toolkit, their application to astronomical problems is not without its issues. In this paper, we will review some of the challenges posed by trying to identify variable stars in large data collections, including appropriate feature representations, dealing with uncertainties, establishing ground truths, and simple discrete classes.

  15. Large interannual variability in net ecosystem carbon dioxide exchange of a disturbed temperate peatland.

    Science.gov (United States)

    Aslan-Sungur, Guler; Lee, Xuhui; Evrendilek, Fatih; Karakaya, Nusret

    2016-06-01

    Peatland ecosystems play an important role in the global carbon (C) cycle as significant C sinks. However, human-induced disturbances can turn these sinks into sources of atmospheric CO2. Long-term measurements are needed to understand seasonal and interannual variability of net ecosystem CO2 exchange (NEE) and effects of hydrological conditions and their disturbances on C fluxes. Continuous eddy-covariance measurements of NEE were conducted between August 2010 and April 2014 at Yenicaga temperate peatland (Turkey), which was drained for agricultural usage and for peat mining until 2009. Annual NEE during the three full years of measurement indicated that the peatland acted as a CO2 source with large interannual variability, at rates of 246, 244 and 663 g Cm(-2)yr(-1) for 2011, 2012, and 2013 respectively, except for June 2011, and May to July 2012. The emission strengths were comparable to those found for severely disturbed tropical peatlands. The peak CO2 emissions occurred in the dry summer of 2013 when water table level (WTL) was below a threshold value of -60 cm and soil water content (SCW) below a threshold value of 70% by volume. Water availability index was found to have a stronger explanatory power for variations in monthly ecosystem respiration (ER) than the traditional water status indicators (SCW and WTL). Air temperature, evapotranspiration and vapor pressure deficient were the most significant variables strongly correlated with NEE and its component fluxes of gross primary production and ER. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Large variability of bathypelagic microbial eukaryotic communities across the world's oceans.

    Science.gov (United States)

    Pernice, Massimo C; Giner, Caterina R; Logares, Ramiro; Perera-Bel, Júlia; Acinas, Silvia G; Duarte, Carlos M; Gasol, Josep M; Massana, Ramon

    2016-04-01

    In this work, we study the diversity of bathypelagic microbial eukaryotes (0.8-20 μm) in the global ocean. Seawater samples from 3000 to 4000 m depth from 27 stations in the Atlantic, Pacific and Indian Oceans were analyzed by pyrosequencing the V4 region of the 18S ribosomal DNA. The relative abundance of the most abundant operational taxonomic units agreed with the results of a parallel metagenomic analysis, suggesting limited PCR biases in the tag approach. Although rarefaction curves for single stations were seldom saturated, the global analysis of all sequences together suggested an adequate recovery of bathypelagic diversity. Community composition presented a large variability among samples, which was poorly explained by linear geographic distance. In fact, the similarity between communities was better explained by water mass composition (26% of the variability) and the ratio in cell abundance between prokaryotes and microbial eukaryotes (21%). Deep diversity appeared dominated by four taxonomic groups (Collodaria, Chrysophytes, Basidiomycota and MALV-II) appearing in different proportions in each sample. Novel diversity amounted to 1% of the pyrotags and was lower than expected. Our study represents an essential step in the investigation of bathypelagic microbial eukaryotes, indicating dominating taxonomic groups and suggesting idiosyncratic assemblages in distinct oceanic regions.

  17. Large variability of bathypelagic microbial eukaryotic communities across the world’s oceans

    KAUST Repository

    Pernice, Massimo C.

    2015-10-09

    In this work, we study the diversity of bathypelagic microbial eukaryotes (0.8–20 μm) in the global ocean. Seawater samples from 3000 to 4000 m depth from 27 stations in the Atlantic, Pacific and Indian Oceans were analyzed by pyrosequencing the V4 region of the 18S ribosomal DNA. The relative abundance of the most abundant operational taxonomic units agreed with the results of a parallel metagenomic analysis, suggesting limited PCR biases in the tag approach. Although rarefaction curves for single stations were seldom saturated, the global analysis of all sequences together suggested an adequate recovery of bathypelagic diversity. Community composition presented a large variability among samples, which was poorly explained by linear geographic distance. In fact, the similarity between communities was better explained by water mass composition (26% of the variability) and the ratio in cell abundance between prokaryotes and microbial eukaryotes (21%). Deep diversity appeared dominated by four taxonomic groups (Collodaria, Chrysophytes, Basidiomycota and MALV-II) appearing in different proportions in each sample. Novel diversity amounted to 1% of the pyrotags and was lower than expected. Our study represents an essential step in the investigation of bathypelagic microbial eukaryotes, indicating dominating taxonomic groups and suggesting idiosyncratic assemblages in distinct oceanic regions.

    The ISME Journal advance online publication, 9 October 2015; doi:10.1038/ismej.2015.170

  18. INFRARED PERIOD-LUMINOSITY RELATIONS OF EVOLVED VARIABLE STARS IN THE LARGE MAGELLANIC CLOUD

    International Nuclear Information System (INIS)

    Riebel, David; Meixner, Margaret; Fraser, Oliver; Srinivasan, Sundar; Cook, Kem; Vijh, Uma

    2010-01-01

    We combine variability information from the MAssive Compact Halo Objects survey of the Large Magellanic Cloud with infrared photometry from the Spitzer Space Telescope Surveying the Agents of a Galaxy's Evolution survey to create a data set of ∼30,000 variable red sources. We photometrically classify these sources as being on the first ascent of the red giant branch, or as being in one of three stages along the asymptotic giant branch (AGB): oxygen-rich, carbon-rich, or highly reddened with indeterminate chemistry ('extreme' AGB candidates). We present linear period-luminosity (P-L) relationships for these sources using eight separate infrared bands (J, H, K s , 3.6, 4.5, 5.8, 8.0, and 24 μm) as proxies for the luminosity. We find that the wavelength dependence of the slope of the P-L relationship is different for different photometrically determined classes of AGB stars. Stars photometrically classified as O-rich show the least variation of slope with wavelength, while dust enshrouded extreme AGB stars show a pronounced trend toward steeper slopes with increasing wavelength. We find that O-rich AGB stars pulsating in the fundamental mode obey a period-magnitude relation with a slope of -3.41 ± 0.04 when magnitude is measured in the 3.6 μm band, in contrast to C-rich AGB stars, which obey a relation of slope -3.77 ± 0.05.

  19. Extreme precipitation variability, forage quality and large herbivore diet selection in arid environments

    Science.gov (United States)

    Cain, James W.; Gedir, Jay V.; Marshal, Jason P.; Krausman, Paul R.; Allen, Jamison D.; Duff, Glenn C.; Jansen, Brian; Morgart, John R.

    2017-01-01

    Nutritional ecology forms the interface between environmental variability and large herbivore behaviour, life history characteristics, and population dynamics. Forage conditions in arid and semi-arid regions are driven by unpredictable spatial and temporal patterns in rainfall. Diet selection by herbivores should be directed towards overcoming the most pressing nutritional limitation (i.e. energy, protein [nitrogen, N], moisture) within the constraints imposed by temporal and spatial variability in forage conditions. We investigated the influence of precipitation-induced shifts in forage nutritional quality and subsequent large herbivore responses across widely varying precipitation conditions in an arid environment. Specifically, we assessed seasonal changes in diet breadth and forage selection of adult female desert bighorn sheep Ovis canadensis mexicana in relation to potential nutritional limitations in forage N, moisture and energy content (as proxied by dry matter digestibility, DMD). Succulents were consistently high in moisture but low in N and grasses were low in N and moisture until the wet period. Nitrogen and moisture content of shrubs and forbs varied among seasons and climatic periods, whereas trees had consistently high N and moderate moisture levels. Shrubs, trees and succulents composed most of the seasonal sheep diets but had little variation in DMD. Across all seasons during drought and during summer with average precipitation, forages selected by sheep were higher in N and moisture than that of available forage. Differences in DMD between sheep diets and available forage were minor. Diet breadth was lowest during drought and increased with precipitation, reflecting a reliance on few key forage species during drought. Overall, forage selection was more strongly associated with N and moisture content than energy content. Our study demonstrates that unlike north-temperate ungulates which are generally reported to be energy-limited, N and moisture

  20. Impact of the Dominant Large-scale Teleconnections on Winter Temperature Variability over East Asia

    Science.gov (United States)

    Lim, Young-Kwon; Kim, Hae-Dong

    2013-01-01

    Monthly mean geopotential height for the past 33 DJF seasons archived in Modern Era Retrospective analysis for Research and Applications reanalysis is decomposed into the large-scale teleconnection patterns to explain their impacts on winter temperature variability over East Asia. Following Arctic Oscillation (AO) that explains the largest variance, East Atlantic/West Russia (EA/WR), West Pacific (WP) and El Nino-Southern Oscillation (ENSO) are identified as the first four leading modes that significantly explain East Asian winter temperature variation. While the northern part of East Asia north of 50N is prevailed by AO and EA/WR impacts, temperature in the midlatitudes (30N-50N), which include Mongolia, northeastern China, Shandong area, Korea, and Japan, is influenced by combined effect of the four leading teleconnections. ENSO impact on average over 33 winters is relatively weaker than the impact of the other three teleconnections. WP impact, which has received less attention than ENSO in earlier studies, characterizes winter temperatures over Korea, Japan, and central to southern China region south of 30N mainly by advective process from the Pacific. Upper level wave activity fluxes reveal that, for the AO case, the height and circulation anomalies affecting midlatitude East Asian winter temperature is mainly located at higher latitudes north of East Asia. Distribution of the fluxes also explains that the stationary wave train associated with EA/WR propagates southeastward from the western Russia, affecting the East Asian winter temperature. Investigation on the impact of each teleconnection for the selected years reveals that the most dominant teleconnection over East Asia is not the same at all years, indicating a great deal of interannual variability. Comparison in temperature anomaly distributions between observation and temperature anomaly constructed using the combined effect of four leading teleconnections clearly show a reasonable consistency between

  1. Orbital diffuse large B-cell lymphoma with combined variable immunodeficiency.

    Science.gov (United States)

    Parikh, Vishal S; Jagadeesh, Deepa; Fernandez, James M; Hsi, Eric D; Singh, Arun D

    2017-10-01

    Common variable immunodeficiency (CVID) is a primary immunodeficiency manifesting as a reduction in the level of total immunoglobulin (Ig) G, a reduction in the level of either IgA or IgM, poor response to polysaccharide vaccine, and usually frequent infections. The association of CVID with an increased risk of malignancy, specifically lymphoma, is well known. A 63-year-old female with a past medical history significant for CVID presented with a 1-month history of dull, left eye pain with proptosis, hypoglobus, and left upper lid fullness without a discrete palpable mass. Magnetic resonance imaging (MRI) of the orbits revealed a diffuse infiltrating orbital mass superonasally with extension into the superior rectus muscle, medial rectus muscle, and optic nerve up to the orbital apex and ethmoid sinus. A superonasal orbital biopsy with a caruncular approach was performed and demonstrated a sparse lymphoid infiltrate that was suggestive for a large B-cell neoplasm. Positron emission tomography (PET) scan demonstrated a hypermetabolic right lymph node, anterior to the right submandibular gland, which was biopsied and histopathology confirmed diffuse large B-cell lymphoma (DLBCL). Our patient achieved a very good response to chemotherapy with minimal residual disease on PET scan at the end of treatment. She attained a complete remission after radiation therapy. In conclusion, patients with new orbital and adnexa masses in the setting of a primary immunodeficiency can have an aggressive malignancy such as DLBCL and early diagnosis and systemic treatment carries a good prognosis.

  2. NOx emissions from large point sources: variability in ozone production, resulting health damages and economic costs

    International Nuclear Information System (INIS)

    Mauzerall, D.L.; Namsoug Kim

    2005-01-01

    We present a proof-of-concept analysis of the measurement of the health damage of ozone (O 3 ) produced from nitrogen oxides (NO x =NO+NO 2 ) emitted by individual large point sources in the eastern United States. We use a regional atmospheric model of the eastern United States, the Comprehensive Air quality Model with Extensions (CAMx), to quantify the variable impact that a fixed quantity of NO x emitted from individual sources can have on the downwind concentration of surface O 3 , depending on temperature and local biogenic hydrocarbon emissions. We also examine the dependence of resulting O 3 -related health damages on the size of the exposed population. The investigation is relevant to the increasingly widely used 'cap and trade' approach to NO x regulation, which presumes that shifts of emission over time and space, holding the total fixed over the course of the summer O 3 season, will have minimal effect on the environmental outcome. By contrast, we show that a shift of a unit of NO x emissions from one place or time to another could result in large changes in resulting health effects due to O 3 formation and exposure. We indicate how the type of modeling carried out here might be used to attach externality-correcting prices to emissions. Charging emitters fees that are commensurate with the damage caused by their NO x emissions would create an incentive for emitters to reduce emissions at times and in locations where they cause the largest damage. (author)

  3. A Spatial Interpolation Framework for Efficient Valuation of Large Portfolios of Variable Annuities

    Directory of Open Access Journals (Sweden)

    Seyed Amir Hejazi

    2017-07-01

    Full Text Available Variable Annuity (VA products expose insurance companies to considerable risk becauseof the guarantees they provide to buyers of these products. Managing and hedging these risks requireinsurers to find the values of key risk metrics for a large portfolio of VA products. In practice, manycompanies rely on nested Monte Carlo (MC simulations to find key risk metrics. MC simulations arecomputationally demanding, forcing insurance companies to invest hundreds of thousands of dollars incomputational infrastructure per year. Moreover, existing academic methodologies are focused on fairvaluation of a single VA contract, exploiting ideas in option theory and regression. In most cases, thecomputational complexity of these methods surpasses the computational requirements of MC simulations.Therefore, academic methodologies cannot scale well to large portfolios of VA contracts. In thispaper, we present a framework for valuing such portfolios based on spatial interpolation. We providea comprehensive study of this framework and compare existing interpolation schemes. Our numericalresults show superior performance, in terms of both computational effciency and accuracy, for thesemethods compared to nested MC simulations. We also present insights into the challenge of findingan effective interpolation scheme in this framework, and suggest guidelines that help us build a fullyautomated scheme that is effcient and accurate.

  4. African aerosol and large-scale precipitation variability over West Africa

    International Nuclear Information System (INIS)

    Huang Jingfeng; Zhang Chidong; Prospero, Joseph M

    2009-01-01

    We investigated the large-scale connection between African aerosol and precipitation in the West African Monsoon (WAM) region using 8-year (2000-2007) monthly and daily Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products (aerosol optical depth, fine mode fraction) and Tropical Rainfall Measuring Mission (TRMM) precipitation and rain type. These high-quality data further confirmed our previous results that the large-scale link between aerosol and precipitation in this region undergoes distinct seasonal and spatial variability. Previously detected suppression of precipitation during months of high aerosol concentration occurs in both convective and stratiform rain, but not systematically in shallow rain. This suggests the suppression of deep convection due to the aerosol. Based on the seasonal cycle of dust and smoke and their geographical distribution, our data suggest that both dust (coarse mode aerosol) and smoke (fine mode aerosol) contribute to the precipitation suppression. However, the dust effect is evident over the Gulf of Guinea while the smoke effect is evident over both land and ocean. A back trajectory analysis further demonstrates that the precipitation reduction is statistically linked to the upwind aerosol concentration. This study suggests that African aerosol outbreaks in the WAM region can influence precipitation in the local monsoon system which has direct societal impact on the local community. It calls for more systematic investigations to determine the modulating mechanisms using both observational and modeling approaches.

  5. How much is too much assessment? Insight into assessment-driven student learning gains in large-scale undergraduate microbiology courses.

    Science.gov (United States)

    Wang, Jack T H; Schembri, Mark A; Hall, Roy A

    2013-01-01

    Designing and implementing assessment tasks in large-scale undergraduate science courses is a labor-intensive process subject to increasing scrutiny from students and quality assurance authorities alike. Recent pedagogical research has provided conceptual frameworks for teaching introductory undergraduate microbiology, but has yet to define best-practice assessment guidelines. This study assessed the applicability of Biggs' theory of constructive alignment in designing consistent learning objectives, activities, and assessment items that aligned with the American Society for Microbiology's concept-based microbiology curriculum in MICR2000, an introductory microbiology course offered at the University of Queensland, Australia. By improving the internal consistency in assessment criteria and increasing the number of assessment items explicitly aligned to the course learning objectives, the teaching team was able to efficiently provide adequate feedback on numerous assessment tasks throughout the semester, which contributed to improved student performance and learning gains. When comparing the constructively aligned 2011 offering of MICR2000 with its 2010 counterpart, students obtained higher marks in both coursework assignments and examinations as the semester progressed. Students also valued the additional feedback provided, as student rankings for course feedback provision increased in 2011 and assessment and feedback was identified as a key strength of MICR2000. By designing MICR2000 using constructive alignment and iterative assessment tasks that followed a common set of learning outcomes, the teaching team was able to effectively deliver detailed and timely feedback in a large introductory microbiology course. This study serves as a case study for how constructive alignment can be integrated into modern teaching practices for large-scale courses.

  6. An ultrahigh vacuum fast-scanning and variable temperature scanning tunneling microscope for large scale imaging.

    Science.gov (United States)

    Diaconescu, Bogdan; Nenchev, Georgi; de la Figuera, Juan; Pohl, Karsten

    2007-10-01

    We describe the design and performance of a fast-scanning, variable temperature scanning tunneling microscope (STM) operating from 80 to 700 K in ultrahigh vacuum (UHV), which routinely achieves large scale atomically resolved imaging of compact metallic surfaces. An efficient in-vacuum vibration isolation and cryogenic system allows for no external vibration isolation of the UHV chamber. The design of the sample holder and STM head permits imaging of the same nanometer-size area of the sample before and after sample preparation outside the STM base. Refractory metal samples are frequently annealed up to 2000 K and their cooldown time from room temperature to 80 K is 15 min. The vertical resolution of the instrument was found to be about 2 pm at room temperature. The coarse motor design allows both translation and rotation of the scanner tube. The total scanning area is about 8 x 8 microm(2). The sample temperature can be adjusted by a few tens of degrees while scanning over the same sample area.

  7. Variability of soil properties within large termite mounds in South Katanga, DRC - origins and applications.

    Science.gov (United States)

    Erens, Hans; Bazirake Mujinya, Basile; Boeckx, Pascal; Baert, Geert; Mees, Florias; Van Ranst, Eric

    2014-05-01

    The miombo woodlands of South Katanga (D.R. Congo) are characterized by a high spatial density of large conic termite mounds built by Macrotermes falciger (3 to 5 ha-1). With an average height of 5.05 m and diameter of 14.88 m, these are some of the largest biogenic structures in the world. The mound material is known to differ considerably from the surrounding Ferralsols. Specifically, mound material exhibits a finer texture, higher CEC and exchangeable basic cation content, lower organic matter content, and an accumulation of phosphorous, nitrate and secondary carbonates. However, as demonstrated by the present study, these soil properties are far from uniform within the volume of the mound. The termites' nesting and foraging activity, combined with pedogenic processes over extended periods of time, generates a wide range of physical, chemical, and biological conditions in different parts of the mound. Analysis of samples taken along a cross-section of a large active mound allowed generating contour plots, thus visualizing the variability of soil properties within the mound. The central columns of three other mounds were sampled to confirm apparent trends. The contour plots show that the mounds comprise four functional zones: (i) the active nest, found at the top; (ii) an accumulation zone , in more central parts of the mound; (iii) a dense inactive zone, surrounding the accumulation zone and consisting of accumulated erosion products from former active nests; and (iv) the outer mantle, characterized by intense varied biological activity and by a well-developed soil structure. Intermittent leaching plays a key role in explaining these patterns. Using radiocarbon dating, we found that some of these mounds are at least 2000 years old. Their current size and shape is likely the result of successive stages of erosion and rebuilding, in the course of alternating periods of mound abandonment and recolonization. Over time, termite foraging combined with limited leaching

  8. Clinical Trials With Large Numbers of Variables: Important Advantages of Canonical Analysis.

    Science.gov (United States)

    Cleophas, Ton J

    2016-01-01

    Canonical analysis assesses the combined effects of a set of predictor variables on a set of outcome variables, but it is little used in clinical trials despite the omnipresence of multiple variables. The aim of this study was to assess the performance of canonical analysis as compared with traditional multivariate methods using multivariate analysis of covariance (MANCOVA). As an example, a simulated data file with 12 gene expression levels and 4 drug efficacy scores was used. The correlation coefficient between the 12 predictor and 4 outcome variables was 0.87 (P = 0.0001) meaning that 76% of the variability in the outcome variables was explained by the 12 covariates. Repeated testing after the removal of 5 unimportant predictor and 1 outcome variable produced virtually the same overall result. The MANCOVA identified identical unimportant variables, but it was unable to provide overall statistics. (1) Canonical analysis is remarkable, because it can handle many more variables than traditional multivariate methods such as MANCOVA can. (2) At the same time, it accounts for the relative importance of the separate variables, their interactions and differences in units. (3) Canonical analysis provides overall statistics of the effects of sets of variables, whereas traditional multivariate methods only provide the statistics of the separate variables. (4) Unlike other methods for combining the effects of multiple variables such as factor analysis/partial least squares, canonical analysis is scientifically entirely rigorous. (5) Limitations include that it is less flexible than factor analysis/partial least squares, because only 2 sets of variables are used and because multiple solutions instead of one is offered. We do hope that this article will stimulate clinical investigators to start using this remarkable method.

  9. North Atlantic cyclones; trends, impacts and links to large-scale variability

    Science.gov (United States)

    Trigo, R. M.; Trigo, I. F.; Ramos, A. M.; Paredes, D.; Garcia-Herrera, R.; Liberato, M. L. R.; Valente, M. A.

    2009-04-01

    Based on the cyclone detection and tracking algorithm previously developed (Trigo, 2006) we have assessed the inter-annual variability and cyclone frequency trends between 1960 and 2000 for the Euro-Atlantic sector using the highest spatial resolution available (1.125° x 1.125°) from the ERA-40 Surface Level Pressure. Additionally, trends for the u and v wind speed components are also computed at the monthly and seasonal scales, using the same dataset. All cyclone and wind speed trend maps were computed with the corresponding statistical significance field. Results reveal a significant frequency decrease (increase) in the western Mediterranean (Greenland and Scandinavia), particularly in December, February and March. Seasonal and monthly analysis of wind speed trends shows similar spatial patterns. We show that these changes in the frequency of low pressure centers and the associated wind patterns are partially responsible for trends of the significant height of waves. Throughout the extended winter months (ONDJFM), regions with positive (negative) wind magnitude trends, of up to 5 cm/s per year, often correspond to regions of positive (negative) significant wave height trends. The cyclone and wind speed trends computed for the JFM months are well matched by the corresponding trends in significant wave height, with February being the month with the highest trends (negative south of 50°N up to -3 cm/year, and positive up to 5cm/year just north of Scotland). Using precipitation data from ECMWF reanalyses and a CRU high resolution dataset we show the impact of these trends in cyclone frequencies upon the corresponding precipitation trends in the influenced areas. It is also shown that these changes are partially linked to major shifts on the indices of large-scale patterns modes, namely the North Atlantic Oscillation (NAO), the Eastern Atlantic (EA) and the Scandinavian Patterns (SCAN). Trigo, I. F. 2006: Climatology and Interannual Variability of Storm-Tracks in

  10. BROAD ABSORPTION LINE VARIABILITY ON MULTI-YEAR TIMESCALES IN A LARGE QUASAR SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Filiz Ak, N.; Brandt, W. N.; Schneider, D. P. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Hall, P. B. [Department of Physics and Astronomy, York University, 4700 Keele St., Toronto, Ontario, M3J 1P3 (Canada); Anderson, S. F. [Astronomy Department, University of Washington, Seattle, WA 98195 (United States); Hamann, F. [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States); Lundgren, B. F. [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Pâris, I. [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Petitjean, P. [Universite Paris 6, Institut d' Astrophysique de Paris, 75014, Paris (France); Ross, Nicholas P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 92420 (United States); Shen, Yue [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS-51, Cambridge, MA 02138 (United States); York, Don, E-mail: nfilizak@astro.psu.edu [The University of Chicago, Department of Astronomy and Astrophysics, Chicago, IL 60637 (United States)

    2013-11-10

    We present a detailed investigation of the variability of 428 C IV and 235 Si IV broad absorption line (BAL) troughs identified in multi-epoch observations of 291 quasars by the Sloan Digital Sky Survey-I/II/III. These observations primarily sample rest-frame timescales of 1-3.7 yr over which significant rearrangement of the BAL wind is expected. We derive a number of observational results on, e.g., the frequency of BAL variability, the velocity range over which BAL variability occurs, the primary observed form of BAL-trough variability, the dependence of BAL variability upon timescale, the frequency of BAL strengthening versus weakening, correlations between BAL variability and BAL-trough profiles, relations between C IV and Si IV BAL variability, coordinated multi-trough variability, and BAL variations as a function of quasar properties. We assess implications of these observational results for quasar winds. Our results support models where most BAL absorption is formed within an order-of-magnitude of the wind-launching radius, although a significant minority of BAL troughs may arise on larger scales. We estimate an average lifetime for a BAL trough along our line-of-sight of a few thousand years. BAL disappearance and emergence events appear to be extremes of general BAL variability, rather than being qualitatively distinct phenomena. We derive the parameters of a random-walk model for BAL EW variability, finding that this model can acceptably describe some key aspects of EW variability. The coordinated trough variability of BAL quasars with multiple troughs suggests that changes in 'shielding gas' may play a significant role in driving general BAL variability.

  11. Dose uncertainties for large solar particle events: Input spectra variability and human geometry approximations

    International Nuclear Information System (INIS)

    Townsend, Lawrence W.; Zapp, E. Neal

    1999-01-01

    The true uncertainties in estimates of body organ absorbed dose and dose equivalent, from exposures of interplanetary astronauts to large solar particle events (SPEs), are essentially unknown. Variations in models used to parameterize SPE proton spectra for input into space radiation transport and shielding computer codes can result in uncertainty about the reliability of dose predictions for these events. Also, different radiation transport codes and their input databases can yield significant differences in dose predictions, even for the same input spectra. Different results may also be obtained for the same input spectra and transport codes if different spacecraft and body self-shielding distributions are assumed. Heretofore there have been no systematic investigations of the variations in dose and dose equivalent resulting from these assumptions and models. In this work we present a study of the variability in predictions of organ dose and dose equivalent arising from the use of different parameters to represent the same incident SPE proton data and from the use of equivalent sphere approximations to represent human body geometry. The study uses the BRYNTRN space radiation transport code to calculate dose and dose equivalent for the skin, ocular lens and bone marrow using the October 1989 SPE as a model event. Comparisons of organ dose and dose equivalent, obtained with a realistic human geometry model and with the oft-used equivalent sphere approximation, are also made. It is demonstrated that variations of 30-40% in organ dose and dose equivalent are obtained for slight variations in spectral fitting parameters obtained when various data points are included or excluded from the fitting procedure. It is further demonstrated that extrapolating spectra from low energy (≤30 MeV) proton fluence measurements, rather than using fluence data extending out to 100 MeV results in dose and dose equivalent predictions that are underestimated by factors as large as 2

  12. Image-based Exploration of Iso-surfaces for Large Multi- Variable Datasets using Parameter Space.

    KAUST Repository

    Binyahib, Roba S.

    2013-05-13

    With an increase in processing power, more complex simulations have resulted in larger data size, with higher resolution and more variables. Many techniques have been developed to help the user to visualize and analyze data from such simulations. However, dealing with a large amount of multivariate data is challenging, time- consuming and often requires high-end clusters. Consequently, novel visualization techniques are needed to explore such data. Many users would like to visually explore their data and change certain visual aspects without the need to use special clusters or having to load a large amount of data. This is the idea behind explorable images (EI). Explorable images are a novel approach that provides limited interactive visualization without the need to re-render from the original data [40]. In this work, the concept of EI has been used to create a workflow that deals with explorable iso-surfaces for scalar fields in a multivariate, time-varying dataset. As a pre-processing step, a set of iso-values for each scalar field is inferred and extracted from a user-assisted sampling technique in time-parameter space. These iso-values are then used to generate iso- surfaces that are then pre-rendered (from a fixed viewpoint) along with additional buffers (i.e. normals, depth, values of other fields, etc.) to provide a compressed representation of iso-surfaces in the dataset. We present a tool that at run-time allows the user to interactively browse and calculate a combination of iso-surfaces superimposed on each other. The result is the same as calculating multiple iso- surfaces from the original data but without the memory and processing overhead. Our tool also allows the user to change the (scalar) values superimposed on each of the surfaces, modify their color map, and interactively re-light the surfaces. We demonstrate the effectiveness of our approach over a multi-terabyte combustion dataset. We also illustrate the efficiency and accuracy of our

  13. Improving seasonal forecasts of hydroclimatic variables through the state of multiple large-scale climate signals

    Science.gov (United States)

    Castelletti, A.; Giuliani, M.; Block, P. J.

    2017-12-01

    Increasingly uncertain hydrologic regimes combined with more frequent and intense extreme events are challenging water systems management worldwide, emphasizing the need of accurate medium- to long-term predictions to timely prompt anticipatory operations. Despite modern forecasts are skillful over short lead time (from hours to days), predictability generally tends to decrease on longer lead times. Global climate teleconnection, such as El Niño Southern Oscillation (ENSO), may contribute in extending forecast lead times. However, ENSO teleconnection is well defined in some locations, such as Western USA and Australia, while there is no consensus on how it can be detected and used in other regions, particularly in Europe, Africa, and Asia. In this work, we generalize the Niño Index Phase Analysis (NIPA) framework by contributing the Multi Variate Niño Index Phase Analysis (MV-NIPA), which allows capturing the state of multiple large-scale climate signals (i.e. ENSO, North Atlantic Oscillation, Pacific Decadal Oscillation, Atlantic Multi-decadal Oscillation, Indian Ocean Dipole) to forecast hydroclimatic variables on a seasonal time scale. Specifically, our approach distinguishes the different phases of the considered climate signals and, for each phase, identifies relevant anomalies in Sea Surface Temperature (SST) that influence the local hydrologic conditions. The potential of the MV-NIPA framework is demonstrated through an application to the Lake Como system, a regulated lake in northern Italy which is mainly operated for flood control and irrigation supply. Numerical results show high correlations between seasonal SST values and one season-ahead precipitation in the Lake Como basin. The skill of the resulting MV-NIPA forecast outperforms the one of ECMWF products. This information represents a valuable contribution to partially anticipate the summer water availability, especially during drought events, ultimately supporting the improvement of the Lake Como

  14. Does internal variability change in response to global warming? A large ensemble modelling study of tropical rainfall

    Science.gov (United States)

    Milinski, S.; Bader, J.; Jungclaus, J. H.; Marotzke, J.

    2017-12-01

    There is some consensus on mean state changes of rainfall under global warming; changes of the internal variability, on the other hand, are more difficult to analyse and have not been discussed as much despite their importance for understanding changes in extreme events, such as droughts or floodings. We analyse changes in the rainfall variability in the tropical Atlantic region. We use a 100-member ensemble of historical (1850-2005) model simulations with the Max Planck Institute for Meteorology Earth System Model (MPI-ESM1) to identify changes of internal rainfall variability. To investigate the effects of global warming on the internal variability, we employ an additional ensemble of model simulations with stronger external forcing (1% CO2-increase per year, same integration length as the historical simulations) with 68 ensemble members. The focus of our study is on the oceanic Atlantic ITCZ. We find that the internal variability of rainfall over the tropical Atlantic does change due to global warming and that these changes in variability are larger than changes in the mean state in some regions. From splitting the total variance into patterns of variability, we see that the variability on the southern flank of the ITCZ becomes more dominant, i.e. explaining a larger fraction of the total variance in a warmer climate. In agreement with previous studies, we find that changes in the mean state show an increase and narrowing of the ITCZ. The large ensembles allow us to do a statistically robust differentiation between the changes in variability that can be explained by internal variability and those that can be attributed to the external forcing. Furthermore, we argue that internal variability in a transient climate is only well defined in the ensemble domain and not in the temporal domain, which requires the use of a large ensemble.

  15. Evaluating two model reduction approaches for large scale hedonic models sensitive to omitted variables and multicollinearity

    DEFF Research Database (Denmark)

    Panduro, Toke Emil; Thorsen, Bo Jellesmark

    2014-01-01

    Hedonic models in environmental valuation studies have grown in terms of number of transactions and number of explanatory variables. We focus on the practical challenge of model reduction, when aiming for reliable parsimonious models, sensitive to omitted variable bias and multicollinearity. We...

  16. Gestational weight gain.

    Science.gov (United States)

    Kominiarek, Michelle A; Peaceman, Alan M

    2017-12-01

    Prenatal care providers are advised to evaluate maternal weight at each regularly scheduled prenatal visit, monitor progress toward meeting weight gain goals, and provide individualized counseling if significant deviations from a woman's goals occur. Today, nearly 50% of women exceed their weight gain goals with overweight and obese women having the highest prevalence of excessive weight gain. Risks of inadequate weight gain include low birthweight and failure to initiate breast-feeding whereas the risks of excessive weight gain include cesarean deliveries and postpartum weight retention for the mother and large-for-gestational-age infants, macrosomia, and childhood overweight or obesity for the offspring. Prenatal care providers have many resources and tools to incorporate weight and other health behavior counseling into routine prenatal practices. Because many women are motivated to improve health behaviors, pregnancy is often considered the optimal time to intervene for issues related to eating habits and physical activity to prevent excessive weight gain. Gestational weight gain is a potentially modifiable risk factor for a number of adverse maternal and neonatal outcomes and meta-analyses of randomized controlled trials report that diet or exercise interventions during pregnancy can help reduce excessive weight gain. However, health behavior interventions for gestational weight gain have not significantly improved other maternal and neonatal outcomes and have limited effectiveness in overweight and obese women. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. The Nature of Global Large-scale Sea Level Variability in Relation to Atmospheric Forcing: A Modeling Study

    Science.gov (United States)

    Fukumori, I.; Raghunath, R.; Fu, L. L.

    1996-01-01

    The relation between large-scale sea level variability and ocean circulation is studied using a numerical model. A global primitive equaiton model of the ocean is forced by daily winds and climatological heat fluxes corresponding to the period from January 1992 to February 1996. The physical nature of the temporal variability from periods of days to a year, are examined based on spectral analyses of model results and comparisons with satellite altimetry and tide gauge measurements.

  18. Oceanic mesoscale turbulence drives large biogeochemical interannual variability at middle and high latitudes

    Digital Repository Service at National Institute of Oceanography (India)

    Levy, M.; Resplandy, L.; Lengaigne, M.

    variability was responsible for interannual fluctuations of the subpolar phytoplankton bloom reaching 80% in amplitude and 2 weeks in timing. Over broader scales, the largest impact occurred in the subtropics with interannual variations of 20% in new...

  19. A period-luminosity relation for supergiant red variables in the Large Magellanic Cloud

    International Nuclear Information System (INIS)

    Feast, M.W.; Catchpole, R.M.; Carter, B.S.; Roberts, G.

    1980-01-01

    Infrared photometry for 24 red supergiant variables in the LMC is used to derive bolometric magnitudes. The existence of a period-luminosity relation for these stars is demonstrated and compared with theory. (author)

  20. Variability of Power from Large-Scale Solar Photovoltaic Scenarios in the State of Gujarat: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, B.; Hummon, M.; Cochran, J.; Stoltenberg, B.; Batra, P.; Mehta, B.; Patel, D.

    2014-04-01

    India has ambitious goals for high utilization of variable renewable power from wind and solar, and deployment has been proceeding at a rapid pace. The western state of Gujarat currently has the largest amount of solar generation of any Indian state, with over 855 Megawatts direct current (MWDC). Combined with over 3,240 MW of wind, variable generation renewables comprise nearly 18% of the electric-generating capacity in the state. A new historic 10-kilometer (km) gridded solar radiation data set capturing hourly insolation values for 2002-2011 is available for India. We apply an established method for downscaling hourly irradiance data to one-minute irradiance data at potential PV power production locations for one year, 2006. The objective of this report is to characterize the intra-hour variability of existing and planned photovoltaic solar power generation in the state of Gujarat (a total of 1.9 gigawatts direct current (GWDC)), and of five possible expansion scenarios of solar generation that reflect a range of geographic diversity (each scenario totals 500-1,000 MW of additional solar capacity). The report statistically analyzes one year's worth of power variability data, applied to both the baseline and expansion scenarios, to evaluate diurnal and seasonal power fluctuations, different timescales of variability (e.g., from one to 15 minutes), the magnitude of variability (both total megawatts and relative to installed solar capacity), and the extent to which the variability can be anticipated in advance. The paper also examines how Gujarat Energy Transmission Corporation (GETCO) and the Gujarat State Load Dispatch Centre (SLDC) could make use of the solar variability profiles in grid operations and planning.

  1. Interannual Variability in the Position and Strength of the East Asian Jet Stream and Its Relation to Large - scale Circulation

    Science.gov (United States)

    Chan, Duo; Zhang, Yang; Wu, Qigang

    2013-04-01

    East Asian Jet Stream (EASJ) is charactered by obvious interannual variability in strength and position (latitude), with wide impacts on East Asian climate in all seasons. In this study, two indices are established to measure the interannual variability in intensity and position of EAJS. Possible causing factors, including both local signals and non-local large-scale circulation, are examined using NCAP-NCAR reanalysis data to investigate their relations with jet variation. Our analysis shows that the relationship between the interannual variations of EASJ and these factors depends on seasons. In the summer, both the intensity and position of EASJ are closely related to the meridional gradient of local surface temperature, but display no apparent relationship with the larg-scale circulation. In cold seasons (autumn, winter and spring), both the local factor and the large-scale circulation, i.e. the Pacific/North American teleconnection pattern (PNA), play important roles in the interannual variability of the jet intensity. The variability in the jet position, however, is more correlated to the Arctic Oscillation (AO), especially in winter. Diagnostic analysis indicates that transient eddy activity plays an important role in connecting the interannual variability of EASJ position with AO.

  2. Retrospective analysis of cohort database: Phenotypic variability in a large dataset of patients confirmed to have homozygous familial hypercholesterolemia

    NARCIS (Netherlands)

    Raal, Frederick J.; Sjouke, Barbara; Hovingh, G. Kees; Isaac, Barton F.

    2016-01-01

    These data describe the phenotypic variability in a large cohort of patients confirmed to have homozygous familial hypercholesterolemia. Herein, we describe the observed relationship of treated low-density lipoprotein cholesterol with age. We also overlay the low-density lipoprotein receptor gene

  3. Governance of extended lifecycle in large-scale eHealth initiatives: analyzing variability of enterprise architecture elements.

    Science.gov (United States)

    Mykkänen, Juha; Virkanen, Hannu; Tuomainen, Mika

    2013-01-01

    The governance of large eHealth initiatives requires traceability of many requirements and design decisions. We provide a model which we use to conceptually analyze variability of several enterprise architecture (EA) elements throughout the extended lifecycle of development goals using interrelated projects related to the national ePrescription in Finland.

  4. Relationship between Eurasian large-scale patterns and regional climate variability over the Black and Baltic Seas

    Energy Technology Data Exchange (ETDEWEB)

    Stankunavicius, G.; Pupienis, D. [Vilnius Univ. (Lithuania). Dept. of Hydrology and Climatology; Basharin, D. [National Academy of Science of Ukraine, Sevastopol (Ukraine). Sevastopol Marine Hydrophysical Inst.

    2012-11-01

    Using a NCEP/NCAR Reanalysis dataset and the empirical orthogonal function (EOF) analysis approach we studied interannual to decadal variabilities of the sea-level air pressure (SLP) and the surface air temperature (SAT) fields over Eurasia during the 2nd part of the 20th century. Our results agree with those of the previous studies, which conclude that Eurasian trends are the result of storm-path changes driven by the interdecadal behaviour of the NAO-like meridional dipole pattern in the Atlantic. On interannual and decadal time scales, significant synchronous correlations between correspondent modes of SAT and SLP EOF patterns were found. This fact suggests that there is a strong and stable Eurasian interrelationship between SAT and SLP large-scale fields which affects the local climate of two sub-regions: the Black and Baltic Seas. The climate variability in these sub-regions was studied in terms of Eurasian large-scale surface-temperature and air-pressure patterns responses. We concluded that the sub-regional climate variability substantially differs over the Black and Baltic Seas, and depends on different Eurasian large-scale patterns. We showed that the Baltic Sea region is influenced by the patterns arising primary from NAO-like meridional dipole, as well as Scandinavian patterns, while the Black Sea's SAT/SLP variability is influenced mainly by the second mode EOF (eastern Atlantic) and large scale tropospheric wave structures. (orig.)

  5. Spitzer observations of large amplitude variables in the LMC and IC 1613

    Directory of Open Access Journals (Sweden)

    Whitelock Patricia A.

    2017-01-01

    Full Text Available The 3.6 and 4.5 ìm characteristics of asymptotic giant branch variables in the LMC and IC 1613 are discussed. For C-rich Mira variables there is a very clear periodluminosity-colour relation, where the [3.6] . [4.5] colour is associated with the amount of circumstellar material and correlated with the pulsation amplitude. The [4.5] periodluminosity relation for dusty stars is approximately one mag brighter than for their naked counterparts with comparable periods.

  6. Hydroclimatic variability in the Lake Mondsee region and its relationships with large-scale climate anomaly patterns

    Science.gov (United States)

    Rimbu, Norel; Ionita, Monica; Swierczynski, Tina; Brauer, Achim; Kämpf, Lucas; Czymzik, Markus

    2017-04-01

    Flood triggered detrital layers in varved sediments of Lake Mondsee, located at the northern fringe of the European Alps (47°48'N,13°23'E), provide an important archive of regional hydroclimatic variability during the mid- to late Holocene. To improve the interpretation of the flood layer record in terms of large-scale climate variability, we investigate the relationships between observational hydrological records from the region, like the Mondsee lake level, the runoff of the lake's main inflow Griesler Ache, with observed precipitation and global climate patterns. The lake level shows a strong positive linear trend during the observational period in all seasons. Additionally, lake level presents important interannual to multidecadal variations. These variations are associated with distinct seasonal atmospheric circulation patterns. A pronounced anomalous anticyclonic center over the Iberian Peninsula is associated with high lake levels values during winter. This center moves southwestward during spring, summer and autumn. In the same time, a cyclonic anomaly center is recorded over central and western Europe. This anomalous circulation extends southwestward from winter to autumn. Similar atmospheric circulation patterns are associated with river runoff and precipitation variability from the region. High lake levels are associated with positive local precipitation anomalies in all seasons as well as with negative local temperature anomalies during spring, summer and autumn. A correlation analysis reveals that lake level, runoff and precipitation variability is related to large-scale sea surface temperature anomaly patterns in all seasons suggesting a possible impact of large-scale climatic modes, like the North Atlantic Oscillation and Atlantic Multidecadal Oscillation on hydroclimatic variability in the Lake Mondsee region. The results presented in this study can be used for a more robust interpretation of the long flood layer record from Lake Mondsee sediments

  7. Experience Gained from Construction of Low-Emission Combustion Chambers for On-Land Large-Capacity Gas-Turbine Units: GT24/26

    Science.gov (United States)

    Bulysova, L. A.; Vasil'ev, V. D.; Berne, A. L.; Gutnik, M. M.

    2018-06-01

    This article is the third in a planned series of articles devoted to the experience gained around the world in constructing low-emission combustion chambers for on-land large-capacity (above 250 MW) gas-turbine units (GTUs). The aim of this study is to generalize and analyze the ways in which different designers apply the fuel flow and combustion arrangement principles and the fuel feed control methods. The considered here GT24 and GT26 (GT24/26) gas-turbine units generating electric power at the 60 and 50 Hz frequencies, respectively, are fitted with burners of identical designs. Designed by ABB, these GTUs were previously manufactured by Alstom, and now they are produced by Ansaldo Energia. The efficiency of these GTUs reaches 41% at the 354 MW power output during operation in the simple cycle and 60.5% at the 505MW power output during operation in the combined cycle. Both GTUs comply with all requirements for harmful emissions. The compression ratio is equal to 35. In this article, a system is considered for two-stage fuel combustion in two sequentially arranged low-emission combustion chambers, one of which is placed upstream of the high-pressure turbine (CC1) and the other upstream of the low-pressure turbine (CC2). The article places the main focus on the CC2, which operates with a decreased content of oxygen in the oxidizer supplied to the burner inlets. The original designs of vortex generators and nozzles placed in the flow of hot combustion products going out from the high-pressure turbine are described in detail. The article also presents an original CC2 front plate cooling system, due to which a significantly smaller amount of air fed for cooling has been reached. The article also presents the pressure damping devices incorporated in the chamber, the use of which made it possible to obtain a significantly wider range of CC loads at which its low-emission operation is ensured. The fuel feed adjustment principles and the combustion control methods

  8. ULTRA-LOW AMPLITUDE VARIABLES IN THE LARGE MAGELLANIC CLOUD-CLASSICAL CEPHEIDS, POP. II CEPHEIDS, RV TAU STARS, AND BINARY VARIABLES

    International Nuclear Information System (INIS)

    Robert Buchler, J.; Wood, Peter R.; Soszynski, Igor

    2009-01-01

    A search for variable stars with ultra-low amplitudes (ULAs), in the millimagnitude range, has been made in the combined MACHO and OGLE databases in the broad vicinity of the Cepheid instability strip in the HR diagram. A total of 25 singly periodic and 4 multiply periodic ULA objects have been uncovered. Our analysis does not allow us to distinguish between pulsational and ellipsoidal (binary) variabilities, nor between Large Magellanic Cloud (LMC) and foreground objects. However, the objects are strongly clustered and appear to be associated with the pulsational instability strips of LMC Pop. I and II variables. When combined with the ULA variables of Buchler et al., a total of 20 objects fall close to the classical Cepheid instability strip. However, they appear to fall on parallel period-magnitude (PM) relations that are shifted to slightly higher magnitude which would confer them a different evolutionary status. Low-amplitude RV Tauri and Pop. II Cepheids have been uncovered that do not appear in the MACHO or OGLE catalogs. Interestingly, a set of binaries seem to lie on a PM relation that is essentially parallel to that of the RV Tauri/Pop. II Cepheids.

  9. Climate change effects on historical range and variability of two large landscapes in western Montana, USA

    Science.gov (United States)

    Robert E. Keane; Lisa M. Holsinger; Russell A. Parsons; Kathy Gray

    2008-01-01

    Quantifying the historical range and variability of landscape composition and structure using simulation modeling is becoming an important means of assessing current landscape condition and prioritizing landscapes for ecosystem restoration. However, most simulated time series are generated using static climate conditions which fail to account for the predicted major...

  10. Fossil fleet transition with fuel changes and large scale variable renewable integration

    Energy Technology Data Exchange (ETDEWEB)

    James, Revis [Electric Power Research Institute, Palo Alto, CA (United States); Hesler, Stephen [Electric Power Research Institute, Palo Alto, CA (United States); Bistline, John [Electric Power Research Institute, Palo Alto, CA (United States)

    2015-03-31

    Variability in demand as seen by grid-connected dispatchable generators can increase due to factors such as greater production from variable generation assets (for example, wind and solar), increased reliance on demand response or customer-driven automation, and aggregation of loads. This variability results a need for these generators to operate in a range of different modes, collectively referred to as “flexible operations.” This study is designed to inform power companies, researchers, and policymakers of the scope and trends in increasing levels of flexible operations as well as reliability challenges and impacts for dispatchable assets. Background Because there is rarely a direct monetization of the value of operational flexibility, the decision to provide such flexibility is typically dependent on unit- and region-specific decisions made by asset owners. It is very likely that much greater and more widespread flexible operations capabilities will be needed due to increased variability in demand seen by grid-connected generators, uncertainty regarding investment in new units to provide adequate operational flexibility, and the retirement of older, uncontrolled sub-critical pulverized coal units. Objective To enhance understanding of the technical challenges and operational impacts associated with dispatchable assets needed to increase operational flexibility and support variable demand. Approach The study approach consists of three elements: a literature review of relevant prior studies, analysis of detailed scenarios for evolution of the future fleet over the next 35 years, and engineering assessment of the degree and scope of technical challenges associated with transformation to the future fleet. The study approach integrated two key elements rarely brought together in a single analysis—1) long-term capacity planning, which enables modeling of unit retirements and new asset investments, and 2) unit commitment analysis, which permits examination of

  11. Datafish Multiphase Data Mining Technique to Match Multiple Mutually Inclusive Independent Variables in Large PACS Databases.

    Science.gov (United States)

    Kelley, Brendan P; Klochko, Chad; Halabi, Safwan; Siegal, Daniel

    2016-06-01

    Retrospective data mining has tremendous potential in research but is time and labor intensive. Current data mining software contains many advanced search features but is limited in its ability to identify patients who meet multiple complex independent search criteria. Simple keyword and Boolean search techniques are ineffective when more complex searches are required, or when a search for multiple mutually inclusive variables becomes important. This is particularly true when trying to identify patients with a set of specific radiologic findings or proximity in time across multiple different imaging modalities. Another challenge that arises in retrospective data mining is that much variation still exists in how image findings are described in radiology reports. We present an algorithmic approach to solve this problem and describe a specific use case scenario in which we applied our technique to a real-world data set in order to identify patients who matched several independent variables in our institution's picture archiving and communication systems (PACS) database.

  12. Offshore Variability in Critical Weather Conditions in Large-Scale Wind Based Danish Power System

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Sørensen, Poul Ejnar

    2013-01-01

    of the variability for the 2020 Danish power system, one can see that in the worst case, up to 1500 MW of power can be lost in 30 minutes. We present results showing how this issue is partially solved by the new High Wind Storm Controller presented by Siemens in the TWENTIES project.......Offshore wind power has a significant development potential, especially in North Europe. The geographical concentration of offshore wind power leads to increased variability and in the case of critical weather conditions it may lead to sudden and considerable loss of production. In this context......, the chances of losing several GW of wind power due to critical weather conditions in a very short time period could potentially jeopardize the whole system’s reliability and stability. Forecasting such events is not trivial and the results so far are not encouraging. When assessing the impact...

  13. Secondary Analysis of Large-Scale Assessment Data: An Alternative to Variable-Centred Analysis

    Science.gov (United States)

    Chow, Kui Foon; Kennedy, Kerry John

    2014-01-01

    International large-scale assessments are now part of the educational landscape in many countries and often feed into major policy decisions. Yet, such assessments also provide data sets for secondary analysis that can address key issues of concern to educators and policymakers alike. Traditionally, such secondary analyses have been based on a…

  14. Nature of global large-scale sea level variability in relation to atmospheric forcing: A modeling study

    Science.gov (United States)

    Fukumori, Ichiro; Raghunath, Ramanujam; Fu, Lee-Lueng

    1998-03-01

    The relation between large-scale sea level variability and ocean circulation is studied using a numerical model. A global primitive equation model of the ocean is forced by daily winds and climatological heat fluxes corresponding to the period from January 1992 to January 1994. The physical nature of sea level's temporal variability from periods of days to a year is examined on the basis of spectral analyses of model results and comparisons with satellite altimetry and tide gauge measurements. The study elucidates and diagnoses the inhomogeneous physics of sea level change in space and frequency domain. At midlatitudes, large-scale sea level variability is primarily due to steric changes associated with the seasonal heating and cooling cycle of the surface layer. In comparison, changes in the tropics and high latitudes are mainly wind driven. Wind-driven variability exhibits a strong latitudinal dependence in itself. Wind-driven changes are largely baroclinic in the tropics but barotropic at higher latitudes. Baroclinic changes are dominated by the annual harmonic of the first baroclinic mode and is largest off the equator; variabilities associated with equatorial waves are smaller in comparison. Wind-driven barotropic changes exhibit a notable enhancement over several abyssal plains in the Southern Ocean, which is likely due to resonant planetary wave modes in basins semienclosed by discontinuities in potential vorticity. Otherwise, barotropic sea level changes are typically dominated by high frequencies with as much as half the total variance in periods shorter than 20 days, reflecting the frequency spectra of wind stress curl. Implications of the findings with regards to analyzing observations and data assimilation are discussed.

  15. An exploratory, large-scale study of pain and quality of life outcomes in cancer patients with moderate or severe pain, and variables predicting improvement.

    Science.gov (United States)

    Maximiano, Constanza; López, Iker; Martín, Cristina; Zugazabeitia, Luis; Martí-Ciriquián, Juan L; Núñez, Miguel A; Contreras, Jorge; Herdman, Michael; Traseira, Susana; Provencio, Mariano

    2018-01-01

    There have been few large-scale, real world studies in Spain to assess change in pain and quality of life (QOL) outcomes in cancer patients with moderate to severe pain. This study aimed to assess changes on both outcomes after 3 months of usual care and to investigate factors associated with change in QoL. Large, multi-centre, observational study in patients with lung, head and neck, colorectal or breast cancer experiencing a first episode of moderate to severe pain while attending one of the participating centres. QoL was assessed using the EuroQol-5D questionnaire and pain using the Brief Pain Inventory (BPI). Instruments were administered at baseline and after 3 months of follow up. Multivariate analyses were used to assess the impact of treatment factors, demographic and clinical variables, pain and other symptoms on QoL scores. 1711 patients were included for analysis. After 3 months of usual care, a significant improvement was observed in pain and QoL in all four cancer groups (pbreast cancer patients showed the largest gains. Poorer baseline performance status (ECOG) and the presence of anxiety/depression were associated with significantly poorer QOL outcomes. Improvements in BPI pain scores were associated with improved QoL. In the four cancer types studied, pain and QoL outcomes improved considerably after 3 months of usual care. Improvements in pain made a substantial contribution to QoL gains whilst the presence of anxiety and depression and poor baseline performance status significantly constrained improvement.

  16. Large Scale Variability of Phytoplankton Blooms in the Arctic and Peripheral Seas: Relationships with Sea Ice, Temperature, Clouds, and Wind

    Science.gov (United States)

    Comiso, Josefino C.; Cota, Glenn F.

    2004-01-01

    Spatially detailed satellite data of mean color, sea ice concentration, surface temperature, clouds, and wind have been analyzed to quantify and study the large scale regional and temporal variability of phytoplankton blooms in the Arctic and peripheral seas from 1998 to 2002. In the Arctic basin, phytoplankton chlorophyll displays a large symmetry with the Eastern Arctic having about fivefold higher concentrations than those of the Western Arctic. Large monthly and yearly variability is also observed in the peripheral seas with the largest blooms occurring in the Bering Sea, Sea of Okhotsk, and the Barents Sea during spring. There is large interannual and seasonal variability in biomass with average chlorophyll concentrations in 2002 and 2001 being higher than earlier years in spring and summer. The seasonality in the latitudinal distribution of blooms is also very different such that the North Atlantic is usually most expansive in spring while the North Pacific is more extensive in autumn. Environmental factors that influence phytoplankton growth were examined, and results show relatively high negative correlation with sea ice retreat and strong positive correlation with temperature in early spring. Plankton growth, as indicated by biomass accumulation, in the Arctic and subarctic increases up to a threshold surface temperature of about 276-277 degree K (3-4 degree C) beyond which the concentrations start to decrease suggesting an optimal temperature or nutrient depletion. The correlation with clouds is significant in some areas but negligible in other areas, while the correlations with wind speed and its components are generally weak. The effects of clouds and winds are less predictable with weekly climatologies because of unknown effects of averaging variable and intermittent physical forcing (e.g. over storm event scales with mixing and upwelling of nutrients) and the time scales of acclimation by the phytoplankton.

  17. Important aspects of Eastern Mediterranean large-scale variability revealed from data of three fixed observatories

    Science.gov (United States)

    Bensi, Manuel; Velaoras, Dimitris; Cardin, Vanessa; Perivoliotis, Leonidas; Pethiakis, George

    2015-04-01

    Long-term variations of temperature and salinity observed in the Adriatic and Aegean Seas seem to be regulated by larger-scale circulation modes of the Eastern Mediterranean (EMed) Sea, such as the recently discovered feedback mechanisms, namely the BiOS (Bimodal Oscillating System) and the internal thermohaline pump theories. These theories are the results of interpretation of many years' observations, highlighting possible interactions between two key regions of the EMed. Although repeated oceanographic cruises carried out in the past or planned for the future are a very useful tool for understanding the interaction between the two basins (e.g. alternating dense water formation, salt ingressions), recent long time-series of high frequency (up to 1h) sampling have added valuable information to the interpretation of internal mechanisms for both areas (i.e. mesoscale eddies, evolution of fast internal processes, etc.). During the last 10 years, three deep observatories were deployed and maintained in the Adriatic, Ionian, and Aegean Seas: they are respectively, the E2-M3A, the Pylos, and the E1-M3A. All are part of the largest European network of Fixed Point Open Ocean Observatories (FixO3, http://www.fixo3.eu/). Herein, from the analysis of temperature and salinity, and potential density time series collected at the three sites from the surface down to the intermediate and deep layers, we will discuss the almost perfect anti-correlated behavior between the Adriatic and the Aegean Seas. Our data, collected almost continuously since 2006, reveal that these observatories well represent the thermohaline variability of their own areas. Interestingly, temperature and salinity in the intermediate layer suddenly increased in the South Adriatic from the end of 2011, exactly when they started decreasing in the Aegean Sea. Moreover, Pylos data used together with additional ones (e.g. Absolute dynamic topography, temperature and salinity data from other platforms) collected

  18. On the strong law of large numbers for $\\varphi$-subgaussian random variables

    OpenAIRE

    Zajkowski, Krzysztof

    2016-01-01

    For $p\\ge 1$ let $\\varphi_p(x)=x^2/2$ if $|x|\\le 1$ and $\\varphi_p(x)=1/p|x|^p-1/p+1/2$ if $|x|>1$. For a random variable $\\xi$ let $\\tau_{\\varphi_p}(\\xi)$ denote $\\inf\\{a\\ge 0:\\;\\forall_{\\lambda\\in\\mathbb{R}}\\; \\ln\\mathbb{E}\\exp(\\lambda\\xi)\\le\\varphi_p(a\\lambda)\\}$; $\\tau_{\\varphi_p}$ is a norm in a space $Sub_{\\varphi_p}=\\{\\xi:\\;\\tau_{\\varphi_p}(\\xi)1$) there exist positive constants $c$ and $\\alpha$ such that for every natural number $n$ the following inequality $\\tau_{\\varphi_p}(\\sum_{i=1...

  19. Variable phenotype of Marfan syndrome in two large Australian pedigrees, one of Australian aboriginal origin

    Energy Technology Data Exchange (ETDEWEB)

    Wong, K.K.; Summers, K.M.; West, M.J. [Univ. of Queensland (Australia)] [and others

    1994-09-01

    Marfan syndrome may affect the cardiovascular, ocular and skeletal systems. The gene for this autosomal dominant disease maps to chromosome 15 and codes for the extracellular matrix protein fibrillin. Phenotypic expression is very variable both within and between families, possibly due to the influence of other, unlinked, genetic factors interacting with the fibrillin gene. We report two Australian families which demonstrate the extent of inter- and intra-family phenotypic variability. Eye, cardiac and skeletal assessments were made independently. In the first family, 8 of 12 siblings and 11 of 19 of their children had ectopia lentis with or without other ocular findings. There were few cardiac signs. One child had mitral valve prolapse. He and three other children had mild dilatation of the aorta. Skeletal abnormalities were also found (3 adults and 7 children). Chest wall asymmetry was the most common skeletal finding. This family has less cardiac and skeletal involvement than is usual in Marfan syndrome, although the disease maps to chromosome 15 in the region of the fibrillin gene (LOD=4.8 at {theta}=0 with respect to CYP19). The second family is partly of Australian aboriginal origin. The disease has been traced through 5 generations. To date we have examined 37 of 84 living members. Twenty-three in 3 generations are affected. Five adults and 4 children have moderate to severe aortic dilatation and there has been at least one death due to aortic dissection. However, two adolescents with subluxed lenses and marked skeletal abnormalities have normal aortic diameters, two children have aortic dilatation without other signs and two children have only subluxed lenses. This family shows the range of phenotypic variation which can arise from mutation in the fibrillin gene, which may be influenced by the admixture of Australian aboriginal genes. These two families provide an invaluable resource for studying genetic interactions in this disease.

  20. How uncertainty in socio-economic variables affects large-scale transport model forecasts

    DEFF Research Database (Denmark)

    Manzo, Stefano; Nielsen, Otto Anker; Prato, Carlo Giacomo

    2015-01-01

    A strategic task assigned to large-scale transport models is to forecast the demand for transport over long periods of time to assess transport projects. However, by modelling complex systems transport models have an inherent uncertainty which increases over time. As a consequence, the longer...... the period forecasted the less reliable is the forecasted model output. Describing uncertainty propagation patterns over time is therefore important in order to provide complete information to the decision makers. Among the existing literature only few studies analyze uncertainty propagation patterns over...

  1. Analyzing the Large Number of Variables in Biomedical and Satellite Imagery

    CERN Document Server

    Good, Phillip I

    2011-01-01

    This book grew out of an online interactive offered through statcourse.com, and it soon became apparent to the author that the course was too limited in terms of time and length in light of the broad backgrounds of the enrolled students. The statisticians who took the course needed to be brought up to speed both on the biological context as well as on the specialized statistical methods needed to handle large arrays. Biologists and physicians, even though fully knowledgeable concerning the procedures used to generate microaarrays, EEGs, or MRIs, needed a full introduction to the resampling met

  2. Large-Scale Liquid Hydrogen Testing of Variable Density Multilayer Insulation with a Foam Substrate

    Science.gov (United States)

    Martin, J. J.; Hastings, L.

    2001-01-01

    The multipurpose hydrogen test bed (MHTB), with an 18-cu m liquid hydrogen tank, was used to evaluate a combination foam/multilayer combination insulation (MLI) concept. The foam element (Isofoam SS-1171) insulates during ground hold/ascent flight, and allowed a dry nitrogen purge as opposed to the more complex/heavy helium purge subsystem normally required. The 45-layer MLI was designed for an on-orbit storage period of 45 days. Unique WI features include a variable layer density, larger but fewer double-aluminized Mylar perforations for ascent to orbit venting, and a commercially established roll-wrap installation process that reduced assembly man-hours and resulted in a roust, virtually seamless MLI. Insulation performance was measured during three test series. The spray-on foam insulation (SOFI) successfully prevented purge gas liquefaction within the MLI and resulted in the expected ground hold heat leak of 63 W/sq m. The orbit hold tests resulted in heat leaks of 0.085 and 0.22 W/sq m with warm boundary temperatures of 164 and 305 K, respectively. Compared to the best previously measured performance with a traditional MLI system, a 41-percent heat leak reduction with 25 fewer MLI layers was achieved. The MHTB MLI heat leak is half that calculated for a constant layer density MLI.

  3. A Poisson regression approach to model monthly hail occurrence in Northern Switzerland using large-scale environmental variables

    Science.gov (United States)

    Madonna, Erica; Ginsbourger, David; Martius, Olivia

    2018-05-01

    In Switzerland, hail regularly causes substantial damage to agriculture, cars and infrastructure, however, little is known about its long-term variability. To study the variability, the monthly number of days with hail in northern Switzerland is modeled in a regression framework using large-scale predictors derived from ERA-Interim reanalysis. The model is developed and verified using radar-based hail observations for the extended summer season (April-September) in the period 2002-2014. The seasonality of hail is explicitly modeled with a categorical predictor (month) and monthly anomalies of several large-scale predictors are used to capture the year-to-year variability. Several regression models are applied and their performance tested with respect to standard scores and cross-validation. The chosen model includes four predictors: the monthly anomaly of the two meter temperature, the monthly anomaly of the logarithm of the convective available potential energy (CAPE), the monthly anomaly of the wind shear and the month. This model well captures the intra-annual variability and slightly underestimates its inter-annual variability. The regression model is applied to the reanalysis data back in time to 1980. The resulting hail day time series shows an increase of the number of hail days per month, which is (in the model) related to an increase in temperature and CAPE. The trend corresponds to approximately 0.5 days per month per decade. The results of the regression model have been compared to two independent data sets. All data sets agree on the sign of the trend, but the trend is weaker in the other data sets.

  4. Variability in mutational fitness effects prevents full lethal transitions in large quasispecies populations

    Science.gov (United States)

    Sardanyés, Josep; Simó, Carles; Martínez, Regina; Solé, Ricard V.; Elena, Santiago F.

    2014-04-01

    The distribution of mutational fitness effects (DMFE) is crucial to the evolutionary fate of quasispecies. In this article we analyze the effect of the DMFE on the dynamics of a large quasispecies by means of a phenotypic version of the classic Eigen's model that incorporates beneficial, neutral, deleterious, and lethal mutations. By parameterizing the model with available experimental data on the DMFE of Vesicular stomatitis virus (VSV) and Tobacco etch virus (TEV), we found that increasing mutation does not totally push the entire viral quasispecies towards deleterious or lethal regions of the phenotypic sequence space. The probability of finding regions in the parameter space of the general model that results in a quasispecies only composed by lethal phenotypes is extremely small at equilibrium and in transient times. The implications of our findings can be extended to other scenarios, such as lethal mutagenesis or genomically unstable cancer, where increased mutagenesis has been suggested as a potential therapy.

  5. Spatial and temporal (1963-2012 variability of ichthyofauna in the large lowland Warta River, Poland

    Directory of Open Access Journals (Sweden)

    Andrzej Kruk

    2015-11-01

    Full Text Available The Warta River is a tributary of the Odra (Oder River. It is 795.2 km long. In 1986 the large Jeziorsko dam reservoir was constructed in the 306th km of its course. In the late 1980s, the river pollution assumed its highest level and stopped increasing as the former political system collapsed and many industrial plants went bankrupt. Unified fish electrocatches have been performed along the Warta River since the 1960s. During the last sampling, in 2011-2012, fish fauna in the middle course of the river was in the poorest condition due to the destabilizing upstream impact of the Jeziorsko dam reservoir, large amounts of wastewater input to the river, and the lack of unpolluted tributaries that could serve as sources of recolonizers. The weakest human pressure was reported for the upper and lower courses, which resulted in higher numbers of species significantly preferring them, and the higher species richness. Species richness significantly increased in comparison with the previous sampling occasions (in 1963-66, 1986-88, and 1996-98. Significant increases in the stability of occurrence, abundance or biomass were recorded for many species including burbot, chub, dace, ide, gudgeon, bleak, bitterling, perch and spined loach. Significant declines in the above mentioned population parameters were rare and related mainly to European eel (a migratory species. The previously recorded strong negative trend (declines in rheophils, increase in the dominance of roach and perch has been reversed. However, regenerated fish assemblages were not recorded in 1996-98 (i.e. several years after the beginning of the improvement in water quality but in 2011-2012 (i.e. about one decade later. We have noticed a similar delay in ichthyofauna recovery also in the Pilica River (Vistula system. This is why we believe that about 15 years are necessary to observe a considerable improvement in fish fauna in larger degraded rivers.

  6. Land Use Induced Hydroclimatic Variability Over Large Deforested Areas in Southern Amazon Rainforest

    Science.gov (United States)

    Khanna, J.; Medvigy, D.

    2017-12-01

    Contemporary Amazonian deforestation, which occurs at scales of a few hundreds of kilometers, has been found to induce systematic changes in the regional dry season precipitation. The replacement of rough forest with smooth pasture induces a low level atmospheric convergence and uplift in the downwind and divergence and subsidence in the upwind deforested areas. The resulting precipitation change is about ±30% of the deforested area mean in the two regions respectively. Compared with the increase in non-precipitating cloudiness triggered by small scale clearings prevalent in the early phases of deforestation, this `dynamical mesoscale circulation' can have regional ecological impacts by altering precipitation seasonality and in turn ecosystem dynamics. However, the seasonality and variability of this phenomenon hasn't been studied. Using observations and numerical simulations this study investigates the relationships between the dynamical mechanism and the local- and continental-scale atmospheric conditions to understand the physical controls on this phenomenon on the inter-annual, inter-seasonal and daily time scales. We find that the strength of the dynamical mechanism is controlled mostly by regional scale thermal and dynamical conditions of the boundary layer and not the continental and global scale atmospheric state. The lifting condensation level (thermodynamic control) and wind speed (dynamic control) within the boundary layer have the largest and positive correlations with the dipole strength, which is true although not always significant across time scales. Due to this dependence it is found to be strongest during parts of the year when the atmosphere is relatively stable. Hence, overall this phenomenon is found to be the prevalent convective triggering mechanism during the dry and parts of transition seasons (especially spring), significantly affecting the hydroclimate during this period.

  7. Spatio-seasonal variability of chromophoric dissolved organic matter absorption and responses to photobleaching in a large shallow temperate lake

    Science.gov (United States)

    Encina Aulló-Maestro, María; Hunter, Peter; Spyrakos, Evangelos; Mercatoris, Pierre; Kovács, Attila; Horváth, Hajnalka; Preston, Tom; Présing, Mátyás; Torres Palenzuela, Jesús; Tyler, Andrew

    2017-03-01

    The development and validation of remote-sensing-based approaches for the retrieval of chromophoric dissolved organic matter (CDOM) concentrations requires a comprehensive understanding of the sources and magnitude of variability in the optical properties of dissolved material within lakes. In this study, spatial and seasonal variability in concentration and composition of CDOM and the origin of its variation was studied in Lake Balaton (Hungary), a large temperate shallow lake in central Europe. In addition, we investigated the effect of photobleaching on the optical properties of CDOM through in-lake incubation experiments. There was marked variability throughout the year in CDOM absorption in Lake Balaton (aCDOM(440) = 0. 06-9.01 m-1). The highest values were consistently observed at the mouth of the main inflow (Zala River), which drains humic-rich material from the adjoining Kis-Balaton wetland, but CDOM absorption decreased rapidly towards the east where it was consistently lower and less variable than in the westernmost lake basins. The spectral slope parameter for the interval of 350-500 nm (SCDOM(350-500)) was more variable with increasing distance from the inflow (observed range 0.0161-0.0181 nm-1 for the mouth of the main inflow and 0.0158-0.0300 nm-1 for waters closer to the outflow). However, spatial variation in SCDOM was more constant exhibiting a negative correlation with aCDOM(440). Dissolved organic carbon (DOC) was strongly positively correlated with aCDOM(440) and followed a similar seasonal trend but it demonstrated more variability than either aCDOM or SCDOM with distance through the system. Photobleaching resulting from a 7-day exposure to natural solar UV radiation resulted in a marked decrease in allochthonous CDOM absorption (7.04 to 3.36 m-1, 42 % decrease). Photodegradation also resulted in an increase in the spectral slope coefficient of dissolved material.

  8. Seasonal variability of the inorganic carbon system in a large coastal plain estuary

    Science.gov (United States)

    Joesoef, Andrew; Kirchman, David L.; Sommerfield, Christopher K.; Cai, Wei-Jun

    2017-11-01

    Carbonate geochemistry research in large estuarine systems is limited. More work is needed to understand how changes in land-use activity influence watershed export of organic and inorganic carbon, acids, and nutrients to the coastal ocean. To investigate the seasonal variation of the inorganic carbon system in the Delaware Estuary, one of the largest estuaries along the US east coast, dissolved inorganic carbon (DIC), total alkalinity (TA), and pH were measured along the estuary from June 2013 to April 2015. In addition, DIC, TA, and pH were periodically measured from March to October 2015 in the nontidal freshwater Delaware, Schuylkill, and Christina rivers over a range of discharge conditions. There were strong negative relationships between river TA and discharge, suggesting that changes in HCO3- concentrations reflect dilution of weathering products in the drainage basin. The ratio of DIC to TA, an understudied but important property, was high (1.11) during high discharge and low (0.94) during low discharge, reflecting additional DIC input in the form of carbon dioxide (CO2), most likely from terrestrial organic matter decomposition, rather than bicarbonate (HCO3-) inputs due to drainage basin weathering processes. This is also a result of CO2 loss to the atmosphere due to rapid water transit during the wet season. Our data further show that elevated DIC in the Schuylkill River is substantially different than that in the Delaware River. Thus, tributary contributions must be considered when attributing estuarine DIC sources to the internal carbon cycle versus external processes such as drainage basin mineralogy, weathering intensity, and discharge patterns. Long-term records in the Delaware and Schuylkill rivers indicate shifts toward higher alkalinity in estuarine waters over time, as has been found in other estuaries worldwide. Annual DIC input flux to the estuary and export flux to the coastal ocean are estimated to be 15.7 ± 8.2 × 109 mol C yr-1 and 16

  9. Identifying the Source of Large-Scale Atmospheric Variability in Jupiter

    Science.gov (United States)

    Orton, Glenn

    2011-01-01

    We propose to use the unique mid-infrared filtered imaging and spectroscopic capabilities of the Subaru COMICS instrument to determine the mechanisms associated with recent unusual rapid albedo and color transformations of several of Jupiter's bands, particularly its South Equatorial Belt (SEB), as a means to understand the coupling between its dynamics and chemistry. These observations will characterize the temperature, degree of cloud cover, and distribution of minor gases that serve as indirect tracers of vertical motions in regions that will be undergoing unusual large-scale changes in dynamics and chemistry: the SEB, as well as regions near the equator and Jupiter's North Temperate Belt. COMICS is ideal for this investigation because of its efficiency in doing both imaging and spectroscopy, its 24.5-mum filter that is unique to 8-meter-class telescopes, its wide field of view that allows imaging of nearly all of Jupiter's disk, coupled with a high diffraction-limited angular resolution and optimal mid-infrared atmospheric transparency.

  10. Seasonal variability of the inorganic carbon system in a large coastal plain estuary

    Directory of Open Access Journals (Sweden)

    A. Joesoef

    2017-11-01

    Full Text Available Carbonate geochemistry research in large estuarine systems is limited. More work is needed to understand how changes in land-use activity influence watershed export of organic and inorganic carbon, acids, and nutrients to the coastal ocean. To investigate the seasonal variation of the inorganic carbon system in the Delaware Estuary, one of the largest estuaries along the US east coast, dissolved inorganic carbon (DIC, total alkalinity (TA, and pH were measured along the estuary from June 2013 to April 2015. In addition, DIC, TA, and pH were periodically measured from March to October 2015 in the nontidal freshwater Delaware, Schuylkill, and Christina rivers over a range of discharge conditions. There were strong negative relationships between river TA and discharge, suggesting that changes in HCO3− concentrations reflect dilution of weathering products in the drainage basin. The ratio of DIC to TA, an understudied but important property, was high (1.11 during high discharge and low (0.94 during low discharge, reflecting additional DIC input in the form of carbon dioxide (CO2, most likely from terrestrial organic matter decomposition, rather than bicarbonate (HCO3− inputs due to drainage basin weathering processes. This is also a result of CO2 loss to the atmosphere due to rapid water transit during the wet season. Our data further show that elevated DIC in the Schuylkill River is substantially different than that in the Delaware River. Thus, tributary contributions must be considered when attributing estuarine DIC sources to the internal carbon cycle versus external processes such as drainage basin mineralogy, weathering intensity, and discharge patterns. Long-term records in the Delaware and Schuylkill rivers indicate shifts toward higher alkalinity in estuarine waters over time, as has been found in other estuaries worldwide. Annual DIC input flux to the estuary and export flux to the coastal ocean are estimated to be 15.7 ± 8.2

  11. Adsorption of Polyanion onto Large Alpha Alumina Beads with Variably Charged Surface

    Directory of Open Access Journals (Sweden)

    Tien Duc Pham

    2014-01-01

    Full Text Available Adsorption of strong polyelectrolyte, poly(styrenesulfonate, PSS, of different molecular weights onto large α-Al2O3 beads was systematically investigated as functions of pH and NaCl concentrations. The ultraviolet (UV absorption spectra of PSS at different pH and salt concentrations confirmed that the structure of PSS is independent of pH. With the change of molecular weight from 70 kg/mol (PSS 70 to 1000 kg/mol (PSS 1000, adsorption amount of PSS increases and proton coadsorption on the surface of α-Al2O3 decreases at given pH and salt concentration. It suggests that higher molecular weight of PSS was less flat conformation than lower one. The adsorption density of PSS 70 and PSS 1000 decreases with decreasing salt concentrations, indicating that both electrostatic and nonelectrostatic interactions are involved. Experimental results of both PSS 70 and PSS 1000 adsorption isotherms onto α-Al2O3 at different pH and salt concentrations can be represented well by two-step adsorption model. The effects of molecular weight and salt concentration are explained by structure of adsorbed PSS onto α-Al2O3. The influence of added SDS on the isotherms is evaluated from the sequential adsorption. The SDS uptake onto α-Al2O3 in the presence of hemimicelles can prevent the adsorption of PSS at low concentration so that adsorption of PSS reduces with preadsorbed SDS.

  12. Long-period variables in the Large Magellanic Cloud. II. Infrared photometry, spectral classification, AGB evolution, and spatial distribution

    International Nuclear Information System (INIS)

    Hughes, S.M.G.; Wood, P.R.

    1990-01-01

    Infrared JHK photometry and visual spectra have been obtained for a large sample of long-period variables (LPVs) in the Large Magellanic Cloud (LMC). Various aspects of the asymptotic giant branch (AGB) evolution of LPVs are discussed using these data. The birth/death rate of LPVs of different ages in the LMC is compared with the birth rates of appropriate samples of planetary nebulas, clump stars, Cepheids, and OH/IR stars. It appears that there are much fewer large-amplitude LPVs per unit galactic stellar mass in the LMC than in the Galaxy. It is suggested that this may be due to the fact that the evolved intermediate-age AGB stars in the LMC often turn into carbon stars, which tend to have smaller pulsation amplitudes than M stars. There is also a major discrepancy between the number of LPVs in the LMC (and in the Galaxy) and the number predicted by the theories of AGB evolution, pulsation, and mass loss. A distance modulus to the LMC of 18.66 + or - 0.05 is derived by comparing the LMC LPVs with P about 200 days with the 47 Tucanae Mira variables in the (K, log P) plane. 64 refs

  13. A large-scale study of the random variability of a coding sequence: a study on the CFTR gene.

    Science.gov (United States)

    Modiano, Guido; Bombieri, Cristina; Ciminelli, Bianca Maria; Belpinati, Francesca; Giorgi, Silvia; Georges, Marie des; Scotet, Virginie; Pompei, Fiorenza; Ciccacci, Cinzia; Guittard, Caroline; Audrézet, Marie Pierre; Begnini, Angela; Toepfer, Michael; Macek, Milan; Ferec, Claude; Claustres, Mireille; Pignatti, Pier Franco

    2005-02-01

    Coding single nucleotide substitutions (cSNSs) have been studied on hundreds of genes using small samples (n(g) approximately 100-150 genes). In the present investigation, a large random European population sample (average n(g) approximately 1500) was studied for a single gene, the CFTR (Cystic Fibrosis Transmembrane conductance Regulator). The nonsynonymous (NS) substitutions exhibited, in accordance with previous reports, a mean probability of being polymorphic (q > 0.005), much lower than that of the synonymous (S) substitutions, but they showed a similar rate of subpolymorphic (q < 0.005) variability. This indicates that, in autosomal genes that may have harmful recessive alleles (nonduplicated genes with important functions), genetic drift overwhelms selection in the subpolymorphic range of variability, making disadvantageous alleles behave as neutral. These results imply that the majority of the subpolymorphic nonsynonymous alleles of these genes are selectively negative or even pathogenic.

  14. Archive Inventory Management System (AIMS) — A Fast, Metrics Gathering Framework for Validating and Gaining Insight from Large File-Based Data Archives

    Science.gov (United States)

    Verma, R. V.

    2018-04-01

    The Archive Inventory Management System (AIMS) is a software package for understanding the distribution, characteristics, integrity, and nuances of files and directories in large file-based data archives on a continuous basis.

  15. Lateral Variability of Lava flow Morphologies in the Deccan Traps Large Igneous Province (India)

    Science.gov (United States)

    Vanderkluysen, L.; Rader, E. L.; Self, S.; Clarke, A. B.; Sheth, H.; Moyer, D. K.

    2016-12-01

    In continental flood basalt provinces (CFBs), lava flow morphologies have traditionally been classified in two distinct groups recognizable in the field, expressing two different modes of lava flow emplacement mechanisms: (a) compound lava flow fields dominated by meter-sized pāhoehoe toes and lobes; and (b) inflated sheet lobes tens to hundreds of meters in width and meters to tens of meters in height. Temporal transitions between these two emplacement styles have been recognized in many mafic large igneous provinces worldwide and seem to be a fundamental feature of CFBs. However, lateral variations in these morphologies remain poorly studied and understood. In the Deccan CFB of India, two principal hypotheses have been proposed to account for possible lateral variations in lava flow facies: that smaller toes and lobes occur in distal regions of flow fields, representing breakouts at the edges of larger inflated lavas; or on the contrary that smaller toes and lobes represent proximal facies. We conducted a field study focusing on two of the Deccan's formations, the Khandala and the Poladpur, located in the middle and upper sections of the province's defined chemostratigraphy. We studied nine sections along a 600 km long E-W transect, with the easternmost sections representing the most distal outcrops, ≥ 500 km away from inferred vents. The Khandala Formation is traditionally described as a sequence of three thick inflated sheet lobes in the well-exposed sections of the western Deccan. However, in the central Deccan, we find the Khandala to be much thicker overall, with half of its thickness dominated by small, meter-sized toes and lobes. Inflated sheet lobes of the Khandala are thinner on average in the central Deccan than further to the east or west. We document this transition as occurring progressively in outcrops only 80 km apart. In the Poladpur, the average thickness of inflated sheet lobes increases in distal outcrops of the eastern Deccan. We interpret

  16. Retrospective analysis of cohort database: Phenotypic variability in a large dataset of patients confirmed to have homozygous familial hypercholesterolemia

    Directory of Open Access Journals (Sweden)

    Frederick J. Raal

    2016-06-01

    Full Text Available These data describe the phenotypic variability in a large cohort of patients confirmed to have homozygous familial hypercholesterolemia. Herein, we describe the observed relationship of treated low-density lipoprotein cholesterol with age. We also overlay the low-density lipoprotein receptor gene (LDLR functional status with these phenotypic data. A full description of these data is available in our recent study published in Atherosclerosis, “Phenotype Diversity Among Patients With Homozygous Familial Hypercholesterolemia: A Cohort Study” (Raal et al., 2016 [1].

  17. Receiver Gain Modulation Circuit

    Science.gov (United States)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  18. Observing the Cosmic Microwave Background Polarization with Variable-delay Polarization Modulators for the Cosmology Large Angular Scale Surveyor

    Science.gov (United States)

    Harrington, Kathleen; CLASS Collaboration

    2018-01-01

    The search for inflationary primordial gravitational waves and the optical depth to reionization, both through their imprint on the large angular scale correlations in the polarization of the cosmic microwave background (CMB), has created the need for high sensitivity measurements of polarization across large fractions of the sky at millimeter wavelengths. These measurements are subjected to instrumental and atmospheric 1/f noise, which has motivated the development of polarization modulators to facilitate the rejection of these large systematic effects.Variable-delay polarization modulators (VPMs) are used in the Cosmology Large Angular Scale Surveyor (CLASS) telescopes as the first element in the optical chain to rapidly modulate the incoming polarization. VPMs consist of a linearly polarizing wire grid in front of a moveable flat mirror; varying the distance between the grid and the mirror produces a changing phase shift between polarization states parallel and perpendicular to the grid which modulates Stokes U (linear polarization at 45°) and Stokes V (circular polarization). The reflective and scalable nature of the VPM enables its placement as the first optical element in a reflecting telescope. This simultaneously allows a lock-in style polarization measurement and the separation of sky polarization from any instrumental polarization farther along in the optical chain.The Q-Band CLASS VPM was the first VPM to begin observing the CMB full time in 2016. I will be presenting its design and characterization as well as demonstrating how modulating polarization significantly rejects atmospheric and instrumental long time scale noise.

  19. Sensitivity of tree ring growth to local and large-scale climate variability in a region of Southeastern Brazil

    Science.gov (United States)

    Venegas-González, Alejandro; Chagas, Matheus Peres; Anholetto Júnior, Claudio Roberto; Alvares, Clayton Alcarde; Roig, Fidel Alejandro; Tomazello Filho, Mario

    2016-01-01

    We explored the relationship between tree growth in two tropical species and local and large-scale climate variability in Southeastern Brazil. Tree ring width chronologies of Tectona grandis (teak) and Pinus caribaea (Caribbean pine) trees were compared with local (Water Requirement Satisfaction Index—WRSI, Standardized Precipitation Index—SPI, and Palmer Drought Severity Index—PDSI) and large-scale climate indices that analyze the equatorial pacific sea surface temperature (Trans-Niño Index-TNI and Niño-3.4-N3.4) and atmospheric circulation variations in the Southern Hemisphere (Antarctic Oscillation-AAO). Teak trees showed positive correlation with three indices in the current summer and fall. A significant correlation between WRSI index and Caribbean pine was observed in the dry season preceding tree ring formation. The influence of large-scale climate patterns was observed only for TNI and AAO, where there was a radial growth reduction in months preceding the growing season with positive values of the TNI in teak trees and radial growth increase (decrease) during December (March) to February (May) of the previous (current) growing season with positive phase of the AAO in teak (Caribbean pine) trees. The development of a new dendroclimatological study in Southeastern Brazil sheds light to local and large-scale climate influence on tree growth in recent decades, contributing in future climate change studies.

  20. Large-Scale Processes Associated with Inter-Decadal and Inter-Annual Early Spring Rainfall Variability in Taiwan

    Directory of Open Access Journals (Sweden)

    Jau-Ming Chen

    2016-02-01

    Full Text Available Early spring (March - April rainfall in Taiwan exhibits evident and distinct inter-annual and inter-decadal variability. The inter-annual varibility has a positive correlation with the El Niño/Southern Oscillation while the inter-decadal variability features a phase change beginning in the late 1970s, coherent with the major phase change in the Pacific decadal oscillation. Rainfall variability in both timescales is regulated by large-scale processes showing consistent dynamic features. Rainfall increases are associated with positive sea surface temperature (SST anomalies in the tropical eastern Pacific and negative SST anomalies in the tropical central Pacific. An anomalous lower-level divergent center appears in the tropical central Pacific. Via a Rossby-wave-like response, an anomalous lower-level anticyclone appears to the southeast of Taiwan over the Philippine Sea-tropical western Pacific region, which is accompanied by an anomalous cyclone to the north-northeast of Taiwan. Both circulation anomalies induce anomalous southwesterly flows to enhance moisture flux from the South China Sea onto Taiwan, resulting in significant moisture convergence nearby Taiwan. With enhanced moisture supplied by anomalous southwesterly flows, significant rainfall increases occur in both inter-annual and inter-decadal timescales in early spring rainfall on Taiwan.

  1. Interannual variability of Central European mean temperature in January / February and its relation to the large-scale circulation

    International Nuclear Information System (INIS)

    Werner, P.C.; Storch, H. von

    1993-01-01

    The Central European temperature distribution field, as given by 11 stations (Fanoe, Hamburg, Potsdam, Jena, Frankfurt, Uccle, Hohenpeissenberg, Praha, Wien, Zuerich and Geneve), is analysed with respect to its year-to-year variability. January-February (JF) average temperatures are considered for the interval 1901-80. An Orthogonal Function (EOF) analysis reveals that the JF temperature variability is almost entirely controlled by one EOF with uniform sign. The second EOF represents only 7% of the total variance and describes a north-south gradient. The time coefficient of the first EOF is almost stationary whereas the second pattern describes a slight downward trend at the northern stations and a slight upward trend at the southern stations. The relationship of the temperature field to the large-scale circulation, represented by the North Atlantic/European sea-level pressure (SLP) field, is investigated by means of a Canonical Correlation (CCA) Analysis. Two CCA pairs are identified which account for most of the temperature year-to-year variance and which suggest plausible mechanisms. The CCA pairs fail, however, to consistently link the long-term temperature trends to changes in the large-scale circulation. In the output of a 100-year run with a coupled atmosphere-ocean model (ECHAM1/LSG), the same CCA pairs are found but the strength of the link between Central European temperature and North Atlantic SLP is markedly weaker than in the observed data. (orig.)

  2. Regression-based season-ahead drought prediction for southern Peru conditioned on large-scale climate variables

    Science.gov (United States)

    Mortensen, Eric; Wu, Shu; Notaro, Michael; Vavrus, Stephen; Montgomery, Rob; De Piérola, José; Sánchez, Carlos; Block, Paul

    2018-01-01

    Located at a complex topographic, climatic, and hydrologic crossroads, southern Peru is a semiarid region that exhibits high spatiotemporal variability in precipitation. The economic viability of the region hinges on this water, yet southern Peru is prone to water scarcity caused by seasonal meteorological drought. Meteorological droughts in this region are often triggered during El Niño episodes; however, other large-scale climate mechanisms also play a noteworthy role in controlling the region's hydrologic cycle. An extensive season-ahead precipitation prediction model is developed to help bolster the existing capacity of stakeholders to plan for and mitigate deleterious impacts of drought. In addition to existing climate indices, large-scale climatic variables, such as sea surface temperature, are investigated to identify potential drought predictors. A principal component regression framework is applied to 11 potential predictors to produce an ensemble forecast of regional January-March precipitation totals. Model hindcasts of 51 years, compared to climatology and another model conditioned solely on an El Niño-Southern Oscillation index, achieve notable skill and perform better for several metrics, including ranked probability skill score and a hit-miss statistic. The information provided by the developed model and ancillary modeling efforts, such as extending the lead time of and spatially disaggregating precipitation predictions to the local level as well as forecasting the number of wet-dry days per rainy season, may further assist regional stakeholders and policymakers in preparing for drought.

  3. Perception of gain in U.S.-Soviet arms control

    International Nuclear Information System (INIS)

    D'Anieri, P.J.

    1991-01-01

    Most current work in the field of international cooperation focuses on the resolution of the 'prisoners dilemma.' Such work begins by assuming that the issues under consideration are defined by absolute gains, where both sides can gain simultaneously. But the realist strand of international relations literature holds that this assumption is suspect - that international relations are usually characterized by relative gains, where gain for one side comes only at the others expense. The model developed here uses the question of absolute versus relative gains not as a theoretical assumption, but as a variable to be measured empirically. The hypothesis is that whether or not the US and the Soviet Union cooperate to limit arms competition is largely determined by whether the two sides define the issue in question as one of absolute or relative gains. The 'perception of gain' hypothesis is compared to explanations at the levels of the international system (rational choice), domestic politics, and individual belief systems. Three case studies are used to compare the strengths and weaknesses of each hypothesis. The findings confirmed that perception of gain is an important independent variable affecting arms control outcomes, but none of the theories were completely supported or rejected

  4. Maternal glycated haemoglobin, pre-gestational weight, pregnancy weight gain and risk of large-for-gestational-age babies: a Danish cohort study of 209 singleton Type 1 diabetic pregnancies

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Lauge; Dethlefsen, Claus; Møller, Anna Margrethe

    2007-01-01

    between glycated haemoglobin (HbA1c) and relative risk of delivering an LGA baby was quantified based on logistic regression models and stratified analysis controlling for the five covariates. Results We included 209 singleton pregnancies with assessable HbA1c values of which 59% [95% confidence interval......Aims To examine the association between maternal glycated haemoglobin in the second half of diabetic pregnancies and the relative risk of delivering large-for-gestational-age (LGA) babies, controlling for maternal body mass index (BMI) before pregnancy, weight gain, age, White class and smoking...... (CI) 52-65%] terminated with an LGA baby. Increasing levels of HbA1c, BMI and weight gain were all associated with increasing risk of delivering an LGA baby. Analyses stratified according to maternal BMI showed that the association between HbA1c and risk of delivering an LGA baby was restricted...

  5. The cumulative effects of forest disturbance and climate variability on streamflow components in a large forest-dominated watershed

    Science.gov (United States)

    Li, Qiang; Wei, Xiaohua; Zhang, Mingfang; Liu, Wenfei; Giles-Hansen, Krysta; Wang, Yi

    2018-02-01

    Assessing how forest disturbance and climate variability affect streamflow components is critical for watershed management, ecosystem protection, and engineering design. Previous studies have mainly evaluated the effects of forest disturbance on total streamflow, rarely with attention given to its components (e.g., base flow and surface runoff), particularly in large watersheds (>1000 km2). In this study, the Upper Similkameen River watershed (1810 km2), an international watershed situated between Canada and the USA, was selected to examine how forest disturbance and climate variability interactively affect total streamflow, baseflow, and surface runoff. Baseflow was separated using a combination of the recursive digital filter method and conductivity mass balance method. Time series analysis and modified double mass curves were then employed to quantitatively separate the relative contributions of forest disturbance and climate variability to each streamflow component. Our results showed that average annual baseflow and baseflow index (baseflow/streamflow) were 113.3 ± 35.6 mm year-1 and 0.27 for 1954-2013, respectively. Forest disturbance increased annual streamflow, baseflow, and surface runoff of 27.7 ± 13.7 mm, 7.4 ± 3.6 mm, and 18.4 ± 12.9 mm, respectively, with its relative contributions to the changes in respective streamflow components being 27.0 ± 23.0%, 29.2 ± 23.1%, and 25.7 ± 23.4%, respectively. In contrast, climate variability decreased them by 74.9 ± 13.7 mm, 17.9 ± 3.6 mm, and 53.3 ± 12.9 mm, respectively, with its relative contributions to the changes in respective streamflow components being 73.0 ± 23.0%, 70.8 ± 23.1% and 73.1 ± 23.4%, respectively. Despite working in opposite ways, the impacts of climate variability on annual streamflow, baseflow, and surface runoff were of a much greater magnitude than forest disturbance impacts. This study has important implications for the protection of aquatic habitat, engineering design, and

  6. Consistency and Variability in Talk about "Diversity": An Empirical Analysis of Discursive Scope in Swiss Large Scale Enterprises

    Directory of Open Access Journals (Sweden)

    Anja Ostendorp

    2009-02-01

    Full Text Available Traditionally discussions of "diversity" in organizations either refer to an ideal "management" of a diverse workforce or to specific concerns of minorities. The term diversity, however, entails a growing number of translations. Highlighting this diversity of diversity, the concept cannot be merely conceived of as either social-normative or economic-functional. Therefore, the present study empirically scrutinizes the current scope of diversity-talk in Swiss large scale enterprises from a discursive psychological perspective. First, it provides five so-called interpretative repertoires which focus on: image, market, minorities, themes, and difference. Second, it discusses why and how persons oscillate between consistency and variability whenever they draw upon these different repertoires. Finally, it points out possibilities to combine them. This empirical approach to diversity in organizations offers new aspects to the current debate on diversity and introduces crucial concepts of a discursive psychological analysis. URN: urn:nbn:de:0114-fqs090218

  7. Precise lim sup behavior of probabilities of large deviations for sums of i.i.d. random variables

    Directory of Open Access Journals (Sweden)

    Andrew Rosalsky

    2004-12-01

    Full Text Available Let {X,Xn;n≥1} be a sequence of real-valued i.i.d. random variables and let Sn=∑i=1nXi, n≥1. In this paper, we study the probabilities of large deviations of the form P(Sn>tn1/p, P(Sntn1/p, where t>0 and 0x1/p/ϕ(x=1, then for every t>0, limsupn→∞P(|Sn|>tn1/p/(nϕ(n=tpα.

  8. Effect of variable heat transfer coefficient on tissue temperature next to a large vessel during radiofrequency tumor ablation

    Directory of Open Access Journals (Sweden)

    Pinheiro Cleber

    2008-07-01

    Full Text Available Abstract Background One of the current shortcomings of radiofrequency (RF tumor ablation is its limited performance in regions close to large blood vessels, resulting in high recurrence rates at these locations. Computer models have been used to determine tissue temperatures during tumor ablation procedures. To simulate large vessels, either constant wall temperature or constant convective heat transfer coefficient (h have been assumed at the vessel surface to simulate convection. However, the actual distribution of the temperature on the vessel wall is non-uniform and time-varying, and this feature makes the convective coefficient variable. Methods This paper presents a realistic time-varying model in which h is a function of the temperature distribution at the vessel wall. The finite-element method (FEM was employed in order to model RF hepatic ablation. Two geometrical configurations were investigated. The RF electrode was placed at distances of 1 and 5 mm from a large vessel (10 mm diameter. Results When the ablation procedure takes longer than 1–2 min, the attained coagulation zone obtained with both time-varying h and constant h does not differ significantly. However, for short duration ablation (5–10 s and when the electrode is 1 mm away from the vessel, the use of constant h can lead to errors as high as 20% in the estimation of the coagulation zone. Conclusion For tumor ablation procedures typically lasting at least 5 min, this study shows that modeling the heat sink effect of large vessels by applying constant h as a boundary condition will yield precise results while reducing computational complexity. However, for other thermal therapies with shorter treatment using a time-varying h may be necessary.

  9. Detection of large above-ground biomass variability in lowland forest ecosystems by airborne LiDAR

    Directory of Open Access Journals (Sweden)

    J. Jubanski

    2013-06-01

    Full Text Available Quantification of tropical forest above-ground biomass (AGB over large areas as input for Reduced Emissions from Deforestation and forest Degradation (REDD+ projects and climate change models is challenging. This is the first study which attempts to estimate AGB and its variability across large areas of tropical lowland forests in Central Kalimantan (Indonesia through correlating airborne light detection and ranging (LiDAR to forest inventory data. Two LiDAR height metrics were analysed, and regression models could be improved through the use of LiDAR point densities as input (R2 = 0.88; n = 52. Surveying with a LiDAR point density per square metre of about 4 resulted in the best cost / benefit ratio. We estimated AGB for 600 km of LiDAR tracks and showed that there exists a considerable variability of up to 140% within the same forest type due to varying environmental conditions. Impact from logging operations and the associated AGB losses dating back more than 10 yr could be assessed by LiDAR but not by multispectral satellite imagery. Comparison with a Landsat classification for a 1 million ha study area where AGB values were based on site-specific field inventory data, regional literature estimates, and default values by the Intergovernmental Panel on Climate Change (IPCC showed an overestimation of 43%, 102%, and 137%, respectively. The results show that AGB overestimation may lead to wrong greenhouse gas (GHG emission estimates due to deforestation in climate models. For REDD+ projects this leads to inaccurate carbon stock estimates and consequently to significantly wrong REDD+ based compensation payments.

  10. Energy modeling and analysis for optimal grid integration of large-scale variable renewables using hydrogen storage in Japan

    International Nuclear Information System (INIS)

    Komiyama, Ryoichi; Otsuki, Takashi; Fujii, Yasumasa

    2015-01-01

    Although the extensive introduction of VRs (variable renewables) will play an essential role to resolve energy and environmental issues in Japan after the Fukushima nuclear accident, its large-scale integration would pose a technical challenge in the grid management; as one of technical countermeasures, hydrogen storage receives much attention, as well as rechargeable battery, for controlling the intermittency of VR power output. For properly planning renewable energy policies, energy system modeling is important to quantify and qualitatively understand its potential benefits and impacts. This paper analyzes the optimal grid integration of large-scale VRs using hydrogen storage in Japan by developing a high time-resolution optimal power generation mix model. Simulation results suggest that the installation of hydrogen storage is promoted by both its cost reduction and CO 2 regulation policy. In addition, hydrogen storage turns out to be suitable for storing VR energy in a long period of time. Finally, through a sensitivity analysis of rechargeable battery cost, hydrogen storage is economically competitive with rechargeable battery; the cost of both technologies should be more elaborately recognized for formulating effective energy policies to integrate massive VRs into the country's power system in an economical manner. - Highlights: • Authors analyze hydrogen storage coupled with VRs (variable renewables). • Simulation analysis is done by developing an optimal power generation mix model. • Hydrogen storage installation is promoted by its cost decline and CO 2 regulation. • Hydrogen storage is suitable for storing VR energy in a long period of time. • Hydrogen storage is economically competitive with rechargeable battery

  11. IMPROVED VARIABLE STAR SEARCH IN LARGE PHOTOMETRIC DATA SETS: NEW VARIABLES IN CoRoT FIELD LRa02 DETECTED BY BEST II

    International Nuclear Information System (INIS)

    Fruth, T.; Cabrera, J.; Csizmadia, Sz.; Eigmüller, P.; Erikson, A.; Kirste, S.; Pasternacki, T.; Rauer, H.; Titz-Weider, R.; Kabath, P.; Chini, R.; Lemke, R.; Murphy, M.

    2012-01-01

    The CoRoT field LRa02 has been observed with the Berlin Exoplanet Search Telescope II (BEST II) during the southern summer 2007/2008. A first analysis of stellar variability led to the publication of 345 newly discovered variable stars. Now, a deeper analysis of this data set was used to optimize the variability search procedure. Several methods and parameters have been tested in order to improve the selection process compared to the widely used J index for variability ranking. This paper describes an empirical approach to treat systematic trends in photometric data based upon the analysis of variance statistics that can significantly decrease the rate of false detections. Finally, the process of reanalysis and method improvement has virtually doubled the number of variable stars compared to the first analysis by Kabath et al. A supplementary catalog of 272 previously unknown periodic variables plus 52 stars with suspected variability is presented. Improved ephemerides are given for 19 known variables in the field. In addition, the BEST II results are compared with CoRoT data and its automatic variability classification.

  12. Interannual Variability of the Meridional Width of the Baiu Rainband in June and the Associated Large-Scale Atmospheric Circulations

    Science.gov (United States)

    Tsuji, K.; Tomita, T.

    2016-12-01

    Baiu front, which is defined as a boundary between tropical and polar air masses in the East Asia-western North Pacific sector in boreal early summer, slowly migrates northward with the daily meridional swings. Thus, the interannual variability of meridional width of the baiu rainband reflects the slow northward migration and the daily meridional swings of the baiu front. This study focuses on the meridional width of baiu rainband only in June when the baiu front extends on Japan, and investigates how the width is related to the rainfall of Japan with discussions of associated anomalous large-scale atmospheric circulations. The meridional width of baiu rainband is defined based on the monthly-mean precipitation rate of June, whose threshold is 5mm day-1 that is averaged in 130°-150°E. There is a significant positive correlation between the variations of southern and northern edges of the baiu rainband in June. However, the interannual variance of the southern edge is almost twice larger than that of the northern one. That is, the interannual variability of the meridional width is chiefly caused by the variations of southern edge, and the contribution of northern ones is small. When the meridonal width is narrow (wide), an anomalous anticyclonic (cyclonic) circulation appears to the south of Japan, and the precipitation rate increases (decreases) in the western part of Japan while decreases (increases) in the counterpart. In other words, a local dipole with a node at 140°E appears around Japan in the baiu rainfall anomalies. The anomalous anticyclonic (cyclonic) circulation to the south of Japan, which controls the interannual variability of meridional width of the baiu rainband, is induced by the strength of Indian summer monsoon. When the convective activity of Indian summer monsoon is strong (week), the Tibetan high in the upper troposphere extends more (less) eastward. The induced stronger (weaker) descent leads stronger (weaker) Bonin high in the western

  13. The interannual precipitation variability in the southern part of Iran as linked to large-scale climate modes

    Energy Technology Data Exchange (ETDEWEB)

    Pourasghar, Farnaz; Jahanbakhsh, Saeed; Sari Sarraf, Behrooz [The University of Tabriz, Department of Physical Geography, Faculty of Humanities and Social Science, Tabriz (Iran, Islamic Republic of); Tozuka, Tomoki [The University of Tokyo, Department of Earth and Planetary Science, Graduate School of Science, Tokyo (Japan); Ghaemi, Hooshang [Iran Meteorological Organization, Tehran (Iran, Islamic Republic of); Yamagata, Toshio [The University of Tokyo, Department of Earth and Planetary Science, Graduate School of Science, Tokyo (Japan); Application Laboratory/JAMSTEC, Yokohama, Kanagawa (Japan)

    2012-11-15

    The interannual variation of precipitation in the southern part of Iran and its link with the large-scale climate modes are examined using monthly data from 183 meteorological stations during 1974-2005. The majority of precipitation occurs during the rainy season from October to May. The interannual variation in fall and early winter during the first part of the rainy season shows apparently a significant positive correlation with the Indian Ocean Dipole (IOD) and El Nino-Southern Oscillation (ENSO). However, a partial correlation analysis used to extract the respective influence of IOD and ENSO shows a significant positive correlation only with the IOD and not with ENSO. The southeasterly moisture flux anomaly over the Arabian Sea turns anti-cyclonically and transport more moisture to the southern part of Iran from the Arabian Sea, the Red Sea, and the Persian Gulf during the positive IOD. On the other hand, the moisture flux has northerly anomaly over Iran during the negative IOD, which results in reduced moisture supply from the south. During the latter part of the rainy season in late winter and spring, the interannual variation of precipitation is more strongly influenced by modes of variability over the Mediterranean Sea. The induced large-scale atmospheric circulation anomaly controls moisture supply from the Red Sea and the Persian Gulf. (orig.)

  14. Impact of antihypertensive combination and monotreatments on blood pressure variability: assessment by old and new indices. Data from a large ambulatory blood pressure monitoring database.

    LENUS (Irish Health Repository)

    Parati, Gianfranco

    2014-06-01

    High 24-h ambulatory blood pressure (ABP) variability is associated with poor cardiovascular outcomes. We analysed a large ABP monitoring database containing data from hypertensive patients treated with telmisartan\\/amlodipine combination or various monotherapies with the aim of quantifying the 24-h distribution of blood pressure (BP) reduction by treatment through the smoothness index and of developing and testing a new treatment-on-variability index (TOVI) to quantify the effects of treatment on both mean BP and BP variability.

  15. Variability of Snow Ablation: Consequences for Runoff Generation at the Process Scale and Lessons for Large Cold Regions Catchments

    Science.gov (United States)

    Pomeroy, J. W.; Carey, S. K.; Granger, R. J.; Hedstrom, N. R.; Janowicz, R.; Pietroniro, A.; Quinton, W. L.

    2002-12-01

    The supply of water to large northern catchments such as the Mackenzie and Yukon Rivers is dominated by snowmelt runoff from first order mountain catchments. In order to understand the timing, peak and duration of the snowmelt freshet at larger scale it is important to appreciate the spatial and temporal variability of snowmelt and runoff processes at the source. For this reason a comprehensive hydrology study of a Yukon River headwaters catchment, Wolf Creek Research Basin, near Whitehorse, has focussed on the spatial variability of snow ablation and snowmelt runoff generation and the consequences for the water balance in a mountain tundra zone. In northern mountain tundra, surface energetics vary with receipt of solar radiation, shrub vegetation cover and initial snow accumulation. Therefore the timing of snowmelt is controlled by aspect, in that south facing slopes become snow-free 4-5 weeks before the north facing. Runoff generation differs widely between the slopes; there is normally no spring runoff generated from the south facing slope as all meltwater evaporates or infiltrates. On the north facing slope, snowmelt provides substantial runoff to hillside macropores which rapidly route water to the stream channel. Macropore distribution is associated with organic terrain and discontinuous permafrost, which in turn result from the summer surface energetics. Therefore the influence of small-scale snow redistribution and energetics as controlled by topography must be accounted for when calculating contributing areas to larger scale catchments, and estimating the effectiveness of snowfall in generating streamflow. This concept is quite distinct from the drainage controlled contributing area that has been found useful in temperate-zone hydrology.

  16. Should I Gain Weight?

    Science.gov (United States)

    ... Videos for Educators Search English Español Should I Gain Weight? KidsHealth / For Teens / Should I Gain Weight? ... something about it. Why Do People Want to Gain Weight? Some of the reasons people give for ...

  17. Variability of cold season surface air temperature over northeastern China and its linkage with large-scale atmospheric circulations

    Science.gov (United States)

    Zhuang, Yuanhuang; Zhang, Jingyong; Wang, Lin

    2018-05-01

    Cold temperature anomalies and extremes have profound effects on the society, the economy, and the environment of northeastern China (NEC). In this study, we define the cold season as the months from October to April, and investigate the variability of cold season surface air temperature (CSAT) over NEC and its relationships with large-scale atmospheric circulation patterns for the period 1981-2014. The empirical orthogonal function (EOF) analysis shows that the first EOF mode of the CSAT over NEC is characterized by a homogeneous structure that describes 92.2% of the total variance. The regionally averaged CSAT over NEC is closely linked with the Arctic Oscillation ( r = 0.62, 99% confidence level) and also has a statistically significant relation with the Polar/Eurasian pattern in the cold season. The positive phases of the Arctic Oscillation and the Polar/Eurasian pattern tend to result in a positive geopotential height anomaly over NEC and a weakened East Asian winter monsoon, which subsequently increase the CSAT over NEC by enhancing the downward solar radiation, strengthening the subsidence warming and warm air advection. Conversely, the negative phases of these two climate indices result in opposite regional atmospheric circulation anomalies and decrease the CSAT over NEC.

  18. Variable phenotypic expression and onset in MYH14 distal hereditary motor neuropathy phenotype in a large, multigenerational North American family.

    Science.gov (United States)

    Iyadurai, Stanley; Arnold, W David; Kissel, John T; Ruhno, Corey; Mcgovern, Vicki L; Snyder, Pamela J; Prior, Thomas W; Roggenbuck, Jennifer; Burghes, Arthur H; Kolb, Stephen J

    2017-08-01

    Distal hereditary motor neuropathy (dHMN) causes distal-predominant weakness without prominent sensory loss. Myosin heavy chain disorders most commonly result in distal myopathy and cardiomyopathy with or without hearing loss, but a complex phenotype with dHMN, myopathy, hoarseness, and hearing loss was reported in a Korean family with a c.2822G>T mutation in MYH14. In this study we report phenotypic features in a North American family with the c.2822G>T in MYH14. Clinical and molecular characterization was performed in a large, 6-generation, Caucasian family with MYH14 dHMN. A total of 11 affected and 7 unaffected individuals were evaluated and showed varying age of onset and severity of weakness. Genotypic concordance was confirmed with molecular analysis. Electrophysiological studies demonstrated distal motor axonal degeneration without myopathy in all affected subjects tested. Mutation of MYH14 can result in a range of neuromuscular phenotypes that includes a dHMN and hearing loss phenotype with variable age of onset. Muscle Nerve 56: 341-345, 2017. © 2016 Wiley Periodicals, Inc.

  19. Early studies reported extreme findings with large variability: a meta-epidemiologic study in the field of endocrinology.

    Science.gov (United States)

    Wang, Zhen; Alahdab, Fares; Almasri, Jehad; Haydour, Qusay; Mohammed, Khaled; Abu Dabrh, Abd Moain; Prokop, Larry J; Alfarkh, Wedad; Lakis, Sumaya; Montori, Victor M; Murad, Mohammad Hassan

    2016-04-01

    To evaluate the presence of extreme findings and fluctuation in effect size in endocrinology. We systematically identified all meta-analyses published in 2014 in the field of endocrinology. Within each meta-analysis, the effect size of the primary binary outcome was compared across studies according to their order of publication. We pooled studies using the DerSimonian and Laird random-effects method. Heterogeneity was evaluated using the I(2) and tau(2). Twelve percent of the included 100 meta-analyses reported the largest effect size in the very first published study. The largest effect size occurred in the first 2 earliest studies in 31% of meta-analyses. When the effect size was the largest in the first published study, it was three times larger than the final pooled effect (ratio of rates, 3.26; 95% confidence interval: 1.80, 5.90). The largest heterogeneity measured by I(2) was observed in 18% of the included meta-analyses when combining the first 2 studies or 17% when combing the first 3 studies. In endocrinology, early studies reported extreme findings with large variability. This behavior of the evidence needs to be taken into account when used to formulate clinical policies. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Spatiotemporal variability and meteorological control of particulate matter pollution in a large open-pit coal mining region in Colombia

    Science.gov (United States)

    Morales Rincon, L. A.; Jimenez-Pizarro, R.; Porras-Diaz, H.

    2012-12-01

    Luis Morales-Rincon (1), Hernan Porras-Diaz (1), Rodrigo Jiménez (2,*) (1) Geomatic Research Group, Department of Civil Engineering, Universidad Industrial de Santander, Bucaramanga, Santander 680002, Colombia; (2) Air Quality Research Group, Department of Chemical and Environmental Engineering, Universidad Nacional de Colombia, Bogota, DC 111321, Colombia *Corresponding author: phone +57-1-316-5000 ext. 14099, fax +57-1-316-5334, e-mail rjimenezp@unal.edu.co The semi-desertic area of Central Cesar, Colombia, produced approximately 44 million tons of coal in 2011. This mining activity has been intensively developed since 2005. There are currently 7 large-scale mining projects in that area. The coal industry has strongly impacted not only the ecosystems, but also the neighboring communities around the coal mines. The main goal of the research work was to characterize spatial and temporal variations of particulate matter (total suspended particulates - TSP - and particulate matter below 10 μm - PM10) as measured at various air quality monitoring stations in Cesar's coal industry region as well as to study the relationship between these variability and meteorological factors. The analysis of the meteorological time series of revealed a complex atmospheric circulation in the region. No clear repetitive diurnal circulation patterns were observed, i.e. statistical mean patterns do not physically represent the actual atmospheric circulation. We attribute this complexity to the interdependence between local and synoptic phenomena over a low altitude, relatively flat area. On the other hand, a comparison of air quality in the mining area with a perimeter station indicates that coal industry in central Cesar has a mayor effect on the levels of particulate matter in the region. Particulate matter concentration is highly variable throughout the year. The strong correlation between TSP and PM10 indicates that secondary aerosols are of minor importance. Furthermore, particle

  1. Phenotypic Variability Associated with a Large Recurrent 1q21.1 Microduplication in a Three-Generation Family

    NARCIS (Netherlands)

    Verhagen, Judith M A; De Leeuw, Nicole; Papatsonis, Dimitri N M; Grijseels, Els W M; De Krijger, Ronald R.; Wessels, Marja W.

    2015-01-01

    Recurrent copy number variants of the q21.1 region of chromosome 1 have been associated with variable clinical features, including developmental delay, mild to moderate intellectual disability, psychiatric and behavioral problems, congenital heart malformations, and craniofacial abnormalities. A

  2. Weight Gain during Pregnancy

    Science.gov (United States)

    ... Global Map Premature Birth Report Cards Careers Archives Pregnancy Before or between pregnancies Nutrition, weight & fitness Prenatal ... fitness > Weight gain during pregnancy Weight gain during pregnancy E-mail to a friend Please fill in ...

  3. Preventing Weight Gain

    Science.gov (United States)

    ... Local Programs Related Topics Diabetes Nutrition Preventing Weight Gain Language: English (US) Español (Spanish) Recommend on Facebook ... cancer. Choosing an Eating Plan to Prevent Weight Gain So, how do you choose a healthful eating ...

  4. The modulation of neural gain facilitates a transition between functional segregation and integration in the brain.

    Science.gov (United States)

    Shine, James M; Aburn, Matthew J; Breakspear, Michael; Poldrack, Russell A

    2018-01-29

    Cognitive function relies on a dynamic, context-sensitive balance between functional integration and segregation in the brain. Previous work has proposed that this balance is mediated by global fluctuations in neural gain by projections from ascending neuromodulatory nuclei. To test this hypothesis in silico, we studied the effects of neural gain on network dynamics in a model of large-scale neuronal dynamics. We found that increases in neural gain directed the network through an abrupt dynamical transition, leading to an integrated network topology that was maximal in frontoparietal 'rich club' regions. This gain-mediated transition was also associated with increased topological complexity, as well as increased variability in time-resolved topological structure, further highlighting the potential computational benefits of the gain-mediated network transition. These results support the hypothesis that neural gain modulation has the computational capacity to mediate the balance between integration and segregation in the brain. © 2018, Shine et al.

  5. Operational Analysis of Distribution Systems Featuring Large-scale Variable RES: Contributions of Energy Storage Systems and Switchable Capacitor Banks

    OpenAIRE

    Mário Pascoal Santos Pereira

    2017-01-01

    In the last decade, the level of variable renewable energy sources (RESs) integrated in distribution network systems have been continuously growing. This adds more uncertainty to these systems, which also face many traditional sources of uncertainty, and those pertaining to other emerging technologies such as demand response and electric vehicles. As a result, distribution system operators are finding it increasingly difficult to maintain an optimal operation of such network systems. These ch...

  6. Modeling temporal and large-scale spatial variability of soil respiration from soil water availability, temperature and vegetation productivity indices

    Science.gov (United States)

    Reichstein, Markus; Rey, Ana; Freibauer, Annette; Tenhunen, John; Valentini, Riccardo; Banza, Joao; Casals, Pere; Cheng, Yufu; Grünzweig, Jose M.; Irvine, James; Joffre, Richard; Law, Beverly E.; Loustau, Denis; Miglietta, Franco; Oechel, Walter; Ourcival, Jean-Marc; Pereira, Joao S.; Peressotti, Alessandro; Ponti, Francesca; Qi, Ye; Rambal, Serge; Rayment, Mark; Romanya, Joan; Rossi, Federica; Tedeschi, Vanessa; Tirone, Giampiero; Xu, Ming; Yakir, Dan

    2003-12-01

    Field-chamber measurements of soil respiration from 17 different forest and shrubland sites in Europe and North America were summarized and analyzed with the goal to develop a model describing seasonal, interannual and spatial variability of soil respiration as affected by water availability, temperature, and site properties. The analysis was performed at a daily and at a monthly time step. With the daily time step, the relative soil water content in the upper soil layer expressed as a fraction of field capacity was a good predictor of soil respiration at all sites. Among the site variables tested, those related to site productivity (e.g., leaf area index) correlated significantly with soil respiration, while carbon pool variables like standing biomass or the litter and soil carbon stocks did not show a clear relationship with soil respiration. Furthermore, it was evidenced that the effect of precipitation on soil respiration stretched beyond its direct effect via soil moisture. A general statistical nonlinear regression model was developed to describe soil respiration as dependent on soil temperature, soil water content, and site-specific maximum leaf area index. The model explained nearly two thirds of the temporal and intersite variability of soil respiration with a mean absolute error of 0.82 μmol m-2 s-1. The parameterized model exhibits the following principal properties: (1) At a relative amount of upper-layer soil water of 16% of field capacity, half-maximal soil respiration rates are reached. (2) The apparent temperature sensitivity of soil respiration measured as Q10 varies between 1 and 5 depending on soil temperature and water content. (3) Soil respiration under reference moisture and temperature conditions is linearly related to maximum site leaf area index. At a monthly timescale, we employed the approach by [2002] that used monthly precipitation and air temperature to globally predict soil respiration (T&P model). While this model was able to

  7. Modelling temporal and large-scale spatial variability of soil respiration from soil water availability, temperature and vegetation productivity indices

    Science.gov (United States)

    Reichstein, M.; Rey, A.; Freibauer, A.; Tenhunen, J.; Valentini, R.; Soil Respiration Synthesis Team

    2003-04-01

    Field-chamber measurements of soil respiration from 17 different forest and shrubland sites in Europe and North America were summarized and analyzed with the goal to develop a model describing seasonal, inter-annual and spatial variability of soil respiration as affected by water availability, temperature and site properties. The analysis was performed at a daily and at a monthly time step. With the daily time step, the relative soil water content in the upper soil layer expressed as a fraction of field capacity was a good predictor of soil respiration at all sites. Among the site variables tested, those related to site productivity (e.g. leaf area index) correlated significantly with soil respiration, while carbon pool variables like standing biomass or the litter and soil carbon stocks did not show a clear relationship with soil respiration. Furthermore, it was evidenced that the effect of precipitation on soil respiration stretched beyond its direct effect via soil moisture. A general statistical non-linear regression model was developed to describe soil respiration as dependent on soil temperature, soil water content and site-specific maximum leaf area index. The model explained nearly two thirds of the temporal and inter-site variability of soil respiration with a mean absolute error of 0.82 µmol m-2 s-1. The parameterised model exhibits the following principal properties: 1) At a relative amount of upper-layer soil water of 16% of field capacity half-maximal soil respiration rates are reached. 2) The apparent temperature sensitivity of soil respiration measured as Q10 varies between 1 and 5 depending on soil temperature and water content. 3) Soil respiration under reference moisture and temperature conditions is linearly related to maximum site leaf area index. At a monthly time-scale we employed the approach by Raich et al. (2002, Global Change Biol. 8, 800-812) that used monthly precipitation and air temperature to globally predict soil respiration (T

  8. Simple Crosscutting Concerns Are Not So Simple : Analysing Variability in Large-Scale Idioms-Based Implementations

    NARCIS (Netherlands)

    Bruntink, M.; Van Deursen, A.; d’Hondt, M.; Tourwé, T.

    2007-01-01

    This paper describes a method for studying idioms-based implementations of crosscutting concerns, and our experiences with it in the context of a real-world, large-scale embedded software system. In particular, we analyse a seemingly simple concern, tracing, and show that it exhibits significant

  9. Baseflow recession analysis in a large shale play: Climate variability and anthropogenic alterations mask effects of hydraulic fracturing

    Science.gov (United States)

    Arciniega-Esparza, Saúl; Breña-Naranjo, Jose Agustín; Hernández-Espriú, Antonio; Pedrozo-Acuña, Adrián; Scanlon, Bridget R.; Nicot, Jean Philippe; Young, Michael H.; Wolaver, Brad D.; Alcocer-Yamanaka, Victor Hugo

    2017-10-01

    Water resources development and landscape alteration exert marked impacts on water-cycle dynamics, including areas subjected to hydraulic fracturing (HF) for exploitation of unconventional oil and gas resources found in shale or tight sandstones. Here we apply a conceptual framework for linking baseflow analysis to changes in water demands from different sectors (e.g. oil/gas extraction, irrigation, and municipal consumption) and climatic variability in the semiarid Eagle Ford play in Texas, USA. We hypothesize that, in water-limited regions, baseflow (Qb) changes are partly due (along with climate variability) to groundwater abstraction. For a more realistic assessment, the analysis was conducted in two different sets of unregulated catchments, located outside and inside the Eagle Ford play. Three periods were considered in the analysis related to HF activities: pre-development (1980-2000), moderate (2001-2008) and intensive (2009-2015) periods. Results indicate that in the Eagle Ford play region, temporal changes in baseflow cannot be directly related to the increase in hydraulic fracturing. Instead, substantial baseflow declines during the intensive period of hydraulic fracturing represent the aggregated effects from the combination of: (1) a historical exceptional drought during 2011-2012; (2) increased groundwater-based irrigation; and (3) an intensive hydraulic fracturing activity.

  10. From Drought to Flood: Biological Responses of Large River Salmonids and Emergent Management Challenges Under California's Extreme Hydroclimatic Variability

    Science.gov (United States)

    Anderson, C.

    2017-12-01

    California's hydroclimatic regime is characterized by extreme interannual variability including periodic, multi-year droughts and winter flooding sequences. Statewide, water years 2012-2016 were characterized by extreme drought followed by likely one of the wettest years on record in water year 2017. Similar drought-flood patterns have occurred multiple times both in the contemporary empirical record and reconstructed climate records. Both the extreme magnitude and rapid succession of these hydroclimatic periods pose difficult challenges for water managers and regulatory agencies responsible for providing instream flows to protect and recover threatened and endangered fish species. Principal among these riverine fish species are federally listed winter-run and spring-run Chinook salmon (Oncorhynchus tshawytscha), Central Valley steelhead (Oncorhynchus mykiss), and the pelagic species Delta smelt (Hypomesus transpacificus). Poor instream conditions from 2012-2016 resulted in extremely low abundance estimates and poor overall fish health, and while fish monitoring results from water year 2017 are too preliminary to draw substantive conclusions, early indicators show continued downward population trends despite the historically wet conditions. This poster evaluates California's hydroclimatic conditions over the past decade and quantifies resultant impacts of the 2012-2016 drought and the extremely wet 2017 water year to both adult escapement and juvenile production estimates in California's major inland salmon rivers over that same time span. We will also examine local, state, and federal regulatory actions both in response to the extreme hydroclimatic variability and in preparation for future drought-flood sequences.

  11. Improved flexibility with large-scale variable renewable power in cities through optimal demand side management and power-to-heat conversion

    International Nuclear Information System (INIS)

    Salpakari, Jyri; Mikkola, Jani; Lund, Peter D.

    2016-01-01

    Highlights: • New models for optimal control of shiftable loads and power-to-heat conversion. • Full technical and economic potential with optimal controls. • Detailed time series of shiftable loads based on empirical data. • Case study of Helsinki (Finland) with over 90% share of district heating. • Positive net present values in cost-optimal operation. - Abstract: Solar and wind power are potential carbon-free energy solutions for urban areas, but they are also subject to large variability. At the same time, urban areas offer promising flexibility solutions for balancing variable renewable power. This paper presents models for optimal control of power-to-heat conversion to heating systems and shiftable loads in cities to incorporate large variable renewable power schemes. The power-to-heat systems comprise heat pumps, electric boilers, and thermal storage. The control strategies comprise optimal matching of load and production, and cost-optimal market participation with investment analysis. All analyses are based on hourly data. The models are applied to a case study in Helsinki, Finland. For a scheme providing ca. 50% of all electricity in the city through self-consumption of variable renewables, power-to-heat with thermal storage could absorb all the surplus production. A significant reduction in the net load magnitude was obtained with shiftable loads. Investments to both power-to-heat and load shifting with electric heating and commercial refrigeration have a positive net present value if the resources are controlled cost-optimally.

  12. Quantifying the Relative Contributions of Forest Change and Climatic Variability to Hydrology in Large Watersheds: A Critical Review of Research Methods

    Directory of Open Access Journals (Sweden)

    Xiaohua Wei

    2013-06-01

    Full Text Available Forest change and climatic variability are two major drivers for influencing change in watershed hydrology in forest–dominated watersheds. Quantifying their relative contributions is important to fully understand their individual effects. This review paper summarizes the progress on quantifying the relative contributions of forest or land cover change and climatic variability to hydrology in large watersheds using available case studies. It compared pros and cons of various research methods, identified research challenges and proposed future research priorities. Our synthesis shows that the relative hydrological effects of forest changes and climatic variability are largely dependent on their own change magnitudes and watershed characteristics. In some severely disturbed watersheds, impacts of forest changes or land use changes can be as important as those from climatic variability. This paper provides a brief review on eight selected research methods for this type of research. Because each method or technique has its own strengths and weaknesses, combining two or more methods is a more robust approach than using any single method alone. Future research priorities include conducting more case studies, refining research methods, and considering mechanism-based research using landscape ecology and geochemistry approaches.

  13. The variability of the large genomic segment of Tahyna orthobunyavirus and an all-atom exploration of its anti-viral drug resistance

    Czech Academy of Sciences Publication Activity Database

    Kilian, Patrik; Valdés, James J.; Lecina-Casas, D.; Chrudimský, T.; Růžek, Daniel

    2013-01-01

    Roč. 20, 2013-Dec (2013), s. 304-311 ISSN 1567-1348 R&D Projects: GA ČR GAP502/11/2116; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Tahyna virus * Orthobunyavirus * California complex * Genetic variability * Large genomic segment Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.264, year: 2013

  14. Quantification of climatic feedbacks on the Caspian Sea level variability and impacts from the Caspian Sea on the large-scale atmospheric circulation

    Science.gov (United States)

    Arpe, Klaus; Tsuang, Ben-Jei; Tseng, Yu-Heng; Liu, Xin-Yu; Leroy, Suzanne A. G.

    2018-05-01

    With a fall of the Caspian Sea level (CSL), its size gets smaller and therefore the total evaporation over the sea is reduced. With a reduced evaporation from the sea, the fall of the CSL is weakened. This creates a negative feedback as less evaporation leads to less water losses of the Caspian Sea (CS). On the other hand, less evaporation reduces the water in the atmosphere, which may lead to less precipitation in the catchment area of the CS. The two opposite feedbacks are estimated by using an atmospheric climate model coupled with an ocean model only for the CS with different CS sizes while keeping all other forcings like oceanic sea surface temperatures (SSTs) and leaf area index the same from a global climate simulation. The investigation is concentrated on the medieval period because at that time the CSL changed dramatically from about - 30 to - 19 m below the mean ocean sea level, partly man-made. Models used for simulating the last millennium are not able to change the size of the CS dynamically so far. When results from such simulations are used to investigate the CSL variability and its causes, the present study should help to parameterize its feedbacks. A first assumption that the total evaporation from the CS will vary with the size of the CS (number of grid points representing the sea) is generally confirmed with the model simulations. The decrease of grid points from 15 to 14, 10, 8 or 7 leads to a decrease of evaporation to 96, 77, 70 and 54%. The lower decrease than initially expected from the number of grid points (93, 67, 53 and 47%) is probably due to the fact that there would also be some evaporation at grid points that run dry with a lower CSL but a cooling of the CS SST with increasing CS size in summer may be more important. The reduction of evaporation over the CS means more water for the budget of the whole catchment of the CS (an increase of the CSL) but from the gain through reduced evaporation over the CS, only 70% is found to remain in

  15. QUASI-STELLAR OBJECT SELECTION ALGORITHM USING TIME VARIABILITY AND MACHINE LEARNING: SELECTION OF 1620 QUASI-STELLAR OBJECT CANDIDATES FROM MACHO LARGE MAGELLANIC CLOUD DATABASE

    International Nuclear Information System (INIS)

    Kim, Dae-Won; Protopapas, Pavlos; Alcock, Charles; Trichas, Markos; Byun, Yong-Ik; Khardon, Roni

    2011-01-01

    We present a new quasi-stellar object (QSO) selection algorithm using a Support Vector Machine, a supervised classification method, on a set of extracted time series features including period, amplitude, color, and autocorrelation value. We train a model that separates QSOs from variable stars, non-variable stars, and microlensing events using 58 known QSOs, 1629 variable stars, and 4288 non-variables in the MAssive Compact Halo Object (MACHO) database as a training set. To estimate the efficiency and the accuracy of the model, we perform a cross-validation test using the training set. The test shows that the model correctly identifies ∼80% of known QSOs with a 25% false-positive rate. The majority of the false positives are Be stars. We applied the trained model to the MACHO Large Magellanic Cloud (LMC) data set, which consists of 40 million light curves, and found 1620 QSO candidates. During the selection none of the 33,242 known MACHO variables were misclassified as QSO candidates. In order to estimate the true false-positive rate, we crossmatched the candidates with astronomical catalogs including the Spitzer Surveying the Agents of a Galaxy's Evolution LMC catalog and a few X-ray catalogs. The results further suggest that the majority of the candidates, more than 70%, are QSOs.

  16. VARIABLE STARS IN THE LARGE MAGELLANIC CLOUD GLOBULAR CLUSTER NGC 2257. I. RESULTS BASED ON 2007-2008 B, V PHOTOMETRY

    International Nuclear Information System (INIS)

    Nemec, James M.; Walker, Alistair; Jeon, Young-Beom

    2009-01-01

    The variable stars in the Large Magellanic Cloud star cluster NGC 2257 are reinvestigated using photometry (to ∼20th mag) of over 400 new B, V CCD images taken with the CTIO 0.9 m telescope on 14 nights in 2007 December and 2008 January. New period searches have been made using two independent algorithms (CLEAN, Period04); the resultant periods of most of the stars are consistent with the pulsation periods derived previously, and where there are discrepancies these have been resolved. For the B and V light curves, accurate Fourier coefficients and parameters are given. Six new variable stars have been discovered (V45-50), including a bright candidate long-period variable star showing secondary oscillations (V45) and two anomalously bright RRc stars (V48 and V50), which are shown to be brightened and reddened by nearby red giant stars. Also discovered among the previously known variable stars are three double-mode RR Lyrae stars (V8, V16, and V34) and several Blazhko variables. Archival Hubble Space Telescope images and the photometry by Johnson et al. have been used to define better the properties of the most crowded variable stars. The total number of cluster variable stars now stands at forty-seven: 23 RRab stars, four of which show Blazhko amplitude variations; 20 RRc stars, one showing clear Blazhko variations and another showing possible Blazhko variations; the three RRd stars, all having the dominant period ∼0.36 day and period ratios P 1 /P 0 ∼0.7450; and an LPV star located near the tip of the red giant branch. A comparison of the RRd stars with those in other environments shows them to be most similar to those in IC4499.

  17. Circumpolar assessment of rhizosphere priming shows limited increase in carbon loss estimates for permafrost soils but large regional variability

    Science.gov (United States)

    Wild, B.; Keuper, F.; Kummu, M.; Beer, C.; Blume-Werry, G.; Fontaine, S.; Gavazov, K.; Gentsch, N.; Guggenberger, G.; Hugelius, G.; Jalava, M.; Koven, C.; Krab, E. J.; Kuhry, P.; Monteux, S.; Richter, A.; Shazhad, T.; Dorrepaal, E.

    2017-12-01

    Predictions of soil organic carbon (SOC) losses in the northern circumpolar permafrost area converge around 15% (± 3% standard error) of the initial C pool by 2100 under the RCP 8.5 warming scenario. Yet, none of these estimates consider plant-soil interactions such as the rhizosphere priming effect (RPE). While laboratory experiments have shown that the input of plant-derived compounds can stimulate SOC losses by up to 1200%, the magnitude of RPE in natural ecosystems is unknown and no methods for upscaling exist so far. We here present the first spatial and depth explicit RPE model that allows estimates of RPE on a large scale (PrimeSCale). We combine available spatial data (SOC, C/N, GPP, ALT and ecosystem type) and new ecological insights to assess the importance of the RPE at the circumpolar scale. We use a positive saturating relationship between the RPE and belowground C allocation and two ALT-dependent rooting-depth distribution functions (for tundra and boreal forest) to proportionally assign belowground C allocation and RPE to individual soil depth increments. The model permits to take into account reasonable limiting factors on additional SOC losses by RPE including interactions between spatial and/or depth variation in GPP, plant root density, SOC stocks and ALT. We estimate potential RPE-induced SOC losses at 9.7 Pg C (5 - 95% CI: 1.5 - 23.2 Pg C) by 2100 (RCP 8.5). This corresponds to an increase of the current permafrost SOC-loss estimate from 15% of the initial C pool to about 16%. If we apply an additional molar C/N threshold of 20 to account for microbial C limitation as a requirement for the RPE, SOC losses by RPE are further reduced to 6.5 Pg C (5 - 95% CI: 1.0 - 16.8 Pg C) by 2100 (RCP 8.5). Although our results show that current estimates of permafrost soil C losses are robust without taking into account the RPE, our model also highlights high-RPE risk in Siberian lowland areas and Alaska north of the Brooks Range. The small overall impact of

  18. Antidepressants and Weight Gain

    Science.gov (United States)

    ... 2015;37:46. Blumenthal SR, et al. An electronic health records study of long-term weight gain following antidepressant ... your agreement to the Terms and Conditions and Privacy Policy linked below. Terms and Conditions Privacy Policy ...

  19. Weight gain - unintentional

    Science.gov (United States)

    ... diabetes Hormone changes or medical problems can also cause unintentional weight gain. This may be due to: Cushing syndrome Underactive thyroid, or low thyroid (hypothyroidism) Polycystic ovary syndrome Menopause Pregnancy Bloating, or swelling ...

  20. Assessing the Impact of Forest Change and Climate Variability on Dry Season Runoff by an Improved Single Watershed Approach: A Comparative Study in Two Large Watersheds, China

    Directory of Open Access Journals (Sweden)

    Yiping Hou

    2018-01-01

    Full Text Available Extensive studies on hydrological responses to forest change have been published for centuries, yet partitioning the hydrological effects of forest change, climate variability and other factors in a large watershed remains a challenge. In this study, we developed a single watershed approach combining the modified double mass curve (MDMC and the time series multivariate autoregressive integrated moving average model (ARIMAX to separate the impact of forest change, climate variability and other factors on dry season runoff variation in two large watersheds in China. The Zagunao watershed was examined for the deforestation effect, while the Meijiang watershed was examined to study the hydrological impact of reforestation. The key findings are: (1 both deforestation and reforestation led to significant reductions in dry season runoff, while climate variability yielded positive effects in the studied watersheds; (2 the hydrological response to forest change varied over time due to changes in soil infiltration and evapotranspiration after vegetation regeneration; (3 changes of subalpine natural forests produced greater impact on dry season runoff than alteration of planted forests. These findings are beneficial to water resource and forest management under climate change and highlight a better planning of forest operations and management incorporated trade-off between carbon and water in different forests.

  1. Variability, trends, and teleconnections of stream flows with large-scale climate signals in the Omo-Ghibe River Basin, Ethiopia.

    Science.gov (United States)

    Degefu, Mekonnen Adnew; Bewket, Woldeamlak

    2017-04-01

    This study assesses variability, trends, and teleconnections of stream flow with large-scale climate signals (global sea surface temperatures (SSTs)) for the Omo-Ghibe River Basin of Ethiopia. Fourteen hydrological indices of variability and extremes were defined from daily stream flow data series and analyzed for two common periods, which are 1972-2006 for 5 stations and 1982-2006 for 15 stations. The Mann-Kendall's test was used to detect trends at 0.05 significance level, and simple correlation analysis was applied to evaluate associations between the selected stream flow indices and SSTs. We found weak and mixed (upward and downward) trend signals for annual and wet (Kiremt) season flows. Indices generated for high-flow (flood) magnitudes showed the same weak trend signals. However, trend tests for flood frequencies and low-flow magnitudes showed little evidences of increasing change. It was also found that El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are the major anomalies affecting stream flow variability in the Omo-Ghibe Basin. The strongest associations are observed between ENSO/Niño3.4 and the stream flow in August and September, mean Kiremt flow (July-September), and flood frequency (peak over threshold on average three peaks per year (POT3_Fre)). The findings of this study provide a general overview on the long-term stream flow variability and predictability of stream flows for the Omo-Ghibe River Basin.

  2. Variable-Frequency Ultrasonic Treatment on Microstructure and Mechanical Properties of ZK60 Alloy during Large Diameter Semi-Continuous Casting

    Directory of Open Access Journals (Sweden)

    Xingrui Chen

    2017-05-01

    Full Text Available Traditional fixed-frequency ultrasonic technology and a variable-frequency ultrasonic technology were applied to refine the as-cast microstructure and improve the mechanical properties of a ZK60 (Mg–Zn–Zr alloy during large diameter semi-continuous casting. The acoustic field propagation was obtained by numerical simulation. The microstructure of the as-cast samples was characterized by optical and scanning electron microscopy. The variable-frequency ultrasonic technology shows its outstanding ability in grain refinement compared with traditional fixed-ultrasonic technology. The variable-frequency acoustic field promoted the formation of small α-Mg globular grains and changed the distribution and morphology of β-phases throughout the castings. Ultimate tensile strength and elongation are increased to 280 MPa and 8.9%, respectively, which are 19.1% and 45.9% higher than the values obtained from billets without ultrasonic treatment and are 11.6% and 18.7% higher than fixed-frequency ultrasound treated billets. Different refinement efficiencies appear in different districts of billets attributed to the sound attenuation in melt. The variable-frequency acoustic field improves the refinement effect by enhancing cavitation-enhanced heterogeneous nucleation and dendrite fragmentation effects.

  3. Impact of gestational weight gain and prepregnancy body mass index on the prevalence of large-for-gestational age infants in two cohorts of women with type 1 insulin-dependent diabetes: a cross-sectional population study

    Science.gov (United States)

    Bowers, Katherine; Dolan, Lawrence M; Deka, Ranjan; Jackson, Chandra L; Khoury, Jane C

    2018-01-01

    Objectives Despite improvements in treatment modalities, large-for-gestational age (LGA) prevalence has remained between 30% and 40% among infants of mothers with type 1 insulin-dependent diabetes mellitus (TIDM). Our objective was to estimate LGA prevalence and examine the association between gestational weight gain (GWG) and prepregnancy body mass index (BMI) with LGA among mothers with TIDM. Design Cross-sectional study. Setting Regional data in Cincinnati, Ohio, from the Diabetes in Pregnancy Program Project (PPG), a prospective cohort for the period 1978–1993; national data from Consortium on Safe Labor (CSL), a multicentre cross-sectional study for the period 2002–2008. Participants The study included 333 pregnancies in the PPG and 358 pregnancies in the CSL. Pregnancies delivered prior to 23 weeks’ gestation were excluded. Women with TIDM in the PPG were identified according to physician confirmation of ketoacidosis, and/or c-peptide levels, and by International Classification of Diseases, ninth version codes within the CSL. LGA was identified as birth weight >90th percentile according to gestational age, race and sex. Main outcome measures LGA at birth. Results Mean±SD maternal age at delivery was 26.4±5.1 years for PPG women and 27.5±6.0 years for CSL women, p=0.008. LGA prevalence did not significantly differ between cohorts (PPG: 40.2% vs CSL: 36.6%, p=0.32). More women began pregnancy as overweight in the later cohort (PPG (16.8%) vs CSL (27.1%), pIOM) guidelines was higher in the later CSL (56.2%) vs PPG (42.3%) cohort, pIOM guidelines had a lower LGA prevalence in CSL (PPG: 30.6% vs CSL: 13.7%), p=0.001. Conclusions Normal-weight women with GWG within IOM guidelines experienced a lower LGA prevalence, supporting the importance of adherence to IOM guidelines for GWG to reduce LGA. High BMI and GWG may be hindering a reduction in LGA prevalence. PMID:29602844

  4. Variable partitioning of flow and sediment transfer through a large river diffluence-confluence unit across a monsoonal flood pulse

    Science.gov (United States)

    Hackney, C. R.; Aalto, R. E.; Darby, S. E.; Parsons, D. R.; Leyland, J.; Nicholas, A. P.; Best, J.

    2016-12-01

    Bifurcations represent key morphological nodes within the channel networks of anabranching and braided fluvial channels, playing an important role in controlling local bed morphology, the routing of sediment and water, and defining the stability of the downstream reaches. Herein, we detail field observations of the three-dimensional flow structure, bed morphological changes and partitioning of both flow discharge and suspended sediment through a large diffluence-confluence unit on the Mekong River, Cambodia, across a range of flow stages (from 13,500 m3 s-1 to 27,000 m3 s-1) over the monsoonal flood-pulse cycle. We show that the discharge asymmetry (a measure of the disparity between discharges distributed down the left and right branches of the bifurcation) varies with flow discharge and that the influence of upstream curvature-induced cross-stream water surface slope and bed morphological changes are first-order controls in modulating the asymmetry in bifurcation discharge. Flow discharge is shown to play a key role in defining the morphodynamics of the diffluence-confluence unit downstream of the bifurcation. Our data show that during peak flows (Q 27,000 m3 s-1), the downstream island complex acts as a net sink of suspended sediment (with 2600 kg s-1 being deposited between the diffluence and confluence), whereas during lower flows, on both the rising and falling limbs of the flood wave, the sediment balance is in quasi-equilibrium. We propose a new conceptual model of bifurcation stability that incorporates varying flood discharge and in which the long term stability of the bifurcation, as well as the larger channel planform and morphology of the diffluence-confluence unit, are controlled by the variations in flood discharge.

  5. Receiver gain function: the actual NMR receiver gain

    OpenAIRE

    Mo, Huaping; Harwood, John S.; Raftery, Daniel

    2010-01-01

    The observed NMR signal size depends on the receiver gain parameter. We propose a receiver gain function to characterize how much the raw FID is amplified by the receiver as a function of the receiver gain setting. Although the receiver is linear for a fixed gain setting, the actual gain of the receiver may differ from what the gain setting suggests. Nevertheless, for a given receiver, we demonstrate that the receiver gain function can be calibrated. Such a calibration enables accurate compar...

  6. Continental pollution in the Western Mediterranean basin: large variability of the aerosol single scattering albedo and influence on the direct shortwave radiative effect

    Directory of Open Access Journals (Sweden)

    C. Di Biagio

    2016-08-01

    Full Text Available Pollution aerosols strongly influence the composition of the Western Mediterranean basin, but at present little is known on their optical properties. We report in this study in situ observations of the single scattering albedo (ω of pollution aerosol plumes measured over the Western Mediterranean basin during the TRAQA (TRansport and Air QuAlity airborne campaign in summer 2012. Cases of pollution export from different source regions around the basin and at different altitudes between  ∼  160 and 3500 m above sea level were sampled during the flights. Data from this study show a large variability of ω, with values between 0.84–0.98 at 370 nm and 0.70–0.99 at 950 nm. The single scattering albedo generally decreases with the wavelength, with some exception associated to the mixing of pollution with sea spray or dust particles over the sea surface. The lowest values of ω (0.84–0.70 between 370 and 950 nm are measured in correspondence of a fresh plume possibly linked to ship emissions over the basin. The range of variability of ω observed in this study seems to be independent of the source region around the basin, as well as of the altitude and aging time of the plumes. The observed variability of ω reflects in a large variability for the complex refractive index of pollution aerosols, which is estimated to span in the large range 1.41–1.77 and 0.002–0.097 for the real and the imaginary parts, respectively, between 370 and 950 nm. Radiative calculations in clear-sky conditions were performed with the GAME radiative transfer model to test the sensitivity of the aerosol shortwave Direct Radiative Effect (DRE to the variability of ω as observed in this study. Results from the calculations suggest up to a 50 and 30 % change of the forcing efficiency (FE, i.e. the DRE per unit of optical depth, at the surface (−160/−235 W m−2 τ−1 at 60° solar zenith angle and at the Top-Of-Atmosphere (−137/−92

  7. Population growth rate and genetic variability of small and large populations of Red flour beetle (Tribolium castaneum) following multigenerational exposure to copper.

    Science.gov (United States)

    Laskowski, Ryszard; Radwan, Jacek; Kuduk, Katarzyna; Mendrok, Magdalena; Kramarz, Paulina

    2015-07-01

    We reared large (1000 individuals) and small (20 individuals) populations of Tribolium castaneum on diet contaminated with copper in order to determine if the size of a population affects its ability to adapt to adverse environmental conditions. After 10 generations, we used microsatellite markers to estimate and subsequently compare the genetic variability of the copper-treated populations with that of the control populations, which were reared on uncontaminated medium. Additionally, we conducted a full cross-factorial experiment which evaluated the effects of 10 generations of "pre-exposure" to copper on a population's fitness in control and copper-contaminated environments. In order to distinguish results potentially arising from genetic adaptation from those due to non-genetic effects associated to parental exposure to copper, we subjected also F11 generation, originating from parents not exposed to copper, to the same cross-factorial experiment. The effects of long-term exposure to copper depended on population size: the growth rates of small populations that were pre-exposed to copper were inhibited compared to those of small populations reared in uncontaminated environments. Large Cu-exposed populations had a higher growth rate in the F10 generation compared to the control groups, while the growth rate of the F11 generation was unaffected by copper exposure history. The only factor that had a significant effect on genetic variability was population size, but this was to be expected given the large difference in the number of individuals between large and small populations. Neither copper contamination nor its interaction with population size affected the number of microsatellite alleles retained in the F10 generation.

  8. The variability of tropical ice cloud properties as a function of the large-scale context from ground-based radar-lidar observations over Darwin, Australia

    Science.gov (United States)

    Protat, A.; Delanoë, J.; May, P. T.; Haynes, J.; Jakob, C.; O'Connor, E.; Pope, M.; Wheeler, M. C.

    2011-08-01

    The high complexity of cloud parameterizations now held in models puts more pressure on observational studies to provide useful means to evaluate them. One approach to the problem put forth in the modelling community is to evaluate under what atmospheric conditions the parameterizations fail to simulate the cloud properties and under what conditions they do a good job. It is the ambition of this paper to characterize the variability of the statistical properties of tropical ice clouds in different tropical "regimes" recently identified in the literature to aid the development of better process-oriented parameterizations in models. For this purpose, the statistical properties of non-precipitating tropical ice clouds over Darwin, Australia are characterized using ground-based radar-lidar observations from the Atmospheric Radiation Measurement (ARM) Program. The ice cloud properties analysed are the frequency of ice cloud occurrence, the morphological properties (cloud top height and thickness), and the microphysical and radiative properties (ice water content, visible extinction, effective radius, and total concentration). The variability of these tropical ice cloud properties is then studied as a function of the large-scale cloud regimes derived from the International Satellite Cloud Climatology Project (ISCCP), the amplitude and phase of the Madden-Julian Oscillation (MJO), and the large-scale atmospheric regime as derived from a long-term record of radiosonde observations over Darwin. The vertical variability of ice cloud occurrence and microphysical properties is largest in all regimes (1.5 order of magnitude for ice water content and extinction, a factor 3 in effective radius, and three orders of magnitude in concentration, typically). 98 % of ice clouds in our dataset are characterized by either a small cloud fraction (smaller than 0.3) or a very large cloud fraction (larger than 0.9). In the ice part of the troposphere three distinct layers characterized by

  9. Photomultiplier gain stabilisation

    International Nuclear Information System (INIS)

    Le Baud, P.; Sautiez, B.

    1958-07-01

    By the control and adjustment of magnetic deflection applied to the electron beam of a photomultiplier it has proved possible to flatten the gain curve, forming plateaux at levels dependent upon the voltage at intake. It should be possible to add this simple device to most photomultipliers on the market today. (author) [fr

  10. The effects of control-display gain on performance of race car drivers in an isometric braking task.

    Science.gov (United States)

    de Winter, J C F; de Groot, S

    2012-12-01

    To minimise lap times during car racing, it is important to build up brake forces rapidly and maintain precise control. We examined the effect of the amplification factor (gain) between brake pedal force and a visually represented output value on a driver's ability to track a target value. The test setup was a formula racing car cockpit fitted with an isometric brake pedal. Thirteen racing drivers performed tracking tasks with four control-display gains and two target functions: a step function (35 trials per gain) and a multisine function (15 trials per gain). The control-display gain had only minor effects on root mean-squared error between output value and target value, but it had large effects on build-up speed, overshoot, within-participants variability, and self-reported physical load. The results confirm the hypothesis that choosing an optimum gain involves balancing stability against physical effort.

  11. Learn and gain

    CERN Document Server

    Al-Alami, Suhair Eyad Jamal

    2013-01-01

    Initiating the slogan ""love it, live it"", Learn and Gain includes eight short stories, chosen to illustrate various modes of narration, as well as to provoke reflection and discussion on a range of issues. All texts utilized here illustrate how great writers can, with their insight and gift for words, help us to see the world we live in, in new probing and exciting ways. What characterises the book, the author believes, is the integration of the skills of literary competence, communicative c...

  12. Can rare SAT formulae be easily recognized? On the efficiency of message-passing algorithms for K-SAT at large clause-to-variable ratios

    International Nuclear Information System (INIS)

    Altarelli, Fabrizio; Monasson, Remi; Zamponi, Francesco

    2007-01-01

    For large clause-to-variable ratios, typical K-SAT instances drawn from the uniform distribution have no solution. We argue, based on statistical mechanics calculations using the replica and cavity methods, that rare satisfiable instances from the uniform distribution are very similar to typical instances drawn from the so-called planted distribution, where instances are chosen uniformly between the ones that admit a given solution. It then follows, from a recent article by Feige, Mossel and Vilenchik (2006 Complete convergence of message passing algorithms for some satisfiability problems Proc. Random 2006 pp 339-50), that these rare instances can be easily recognized (in O(log N) time and with probability close to 1) by a simple message-passing algorithm

  13. Enhancement of juvenile Caribbean spiny lobsters: an evaluation of changes in multiple response variables with the addition of large artificial shelters.

    Science.gov (United States)

    Briones-Fourzán, Patricia; Lozano-Alvarez, Enrique; Negrete-Soto, Fernando; Barradas-Ortiz, Cecilia

    2007-03-01

    Shortage of natural crevice shelters may produce population bottlenecks in juvenile Caribbean spiny lobsters (Panulirus argus), a socially gregarious species. We conducted a field experiment to test enhancement of a local population of juvenile P. argus with the addition of artificial shelters ("casitas") that mimic large crevices (1.1 m(2) in surface area and 3.8 cm in height). Changes in density and biomass of juvenile lobsters 15-50 mm carapace length (CL) were assessed with a multiple before-after control-impact (MBACI) analysis. Separate analyses were also conducted on small (15-35 mm CL) and large (35.1-50 mm CL) juveniles to assess size-related effects. First, we carried out 13 lobster surveys on nine fixed 1-ha sites over a shallow reef lagoon ("before" period). Then, we deployed ten casitas in each of five sites and left four sites as controls, and conducted 22 further surveys ("after" period). Deployment of casitas resulted in a sixfold increase in juvenile density (76% contributed by small and 24% by large juveniles) and a sevenfold increase in biomass (40 and 60%, respectively). Capture-recapture results revealed that enhancement was achieved not by promoting individual growth but by increasing survival, persistence, and foraging ranges of small and large juveniles. Casitas both mitigated shortage of natural shelter and increased sociality, allowing for cohabitation of smaller, more vulnerable juveniles with larger conspecifics that have greater defensive abilities. Casitas may help enhance local populations of juvenile P. argus in Caribbean seagrass habitats, typically poor in natural crevice shelters. The use of MBACI and the simultaneous assessment of multiple interrelated response variables may be a powerful analytical approach to test shelter limitation in other species and to examine the function of structural habitat in other systems.

  14. The influence of environmental variables on spatial and temporal phytoplankton dissimilarity in a large shallow subtropical lake (Lake Mangueira, southern Brazil

    Directory of Open Access Journals (Sweden)

    Luciane Oliveira Crossetti

    2014-06-01

    Full Text Available AIM: The uneven distribution of organisms in aquatic ecosystems is generally attributed to environmental heterogeneity in both space and time, reflecting the occurrence of appropriate environmental conditions and the availability of resources to biological communities. The aim of this study was to understand how the dissimilarity of the phytoplankton community in a large subtropical shallow lake is related to environmental dissimilarities. METHODS: Biotic and environmental data were gathered at 19 sites along the 90-km length of Lake Mangueira. Sampling was carried out quarterly during 2010 and 2011, totaling 152 sampling units. The relationship between phytoplankton dissimilarity and the dissimilarity of environmental variables was assessed by the BioEnv analysis. MAJOR RESULTS: There is a significant relationship between phytoplankton dissimilarity and environmental dissimilarity. The model that best explained the dissimilarity of phytoplankton among the sampling units included pH, turbidity and nitrate. CONCLUSIONS: The dissimilarity of phytoplankton was related to the dissimilarity, which were directly associated to the variability of conditions and resources in space and time in Lake Mangueira.

  15. Human choices and environmental constraints: deciphering the variability of large game procurement from Mousterian to Aurignacian times (MIS 5-3) in southwestern France

    Science.gov (United States)

    Discamps, Emmanuel; Jaubert, Jacques; Bachellerie, François

    2011-09-01

    The evolution in the selection of prey made by past humans, especially the Neandertals and the first anatomically modern humans, has been widely debated. Between Marine Isotope Stages (MIS) 5 and 3, the accuracy of absolute dating is still insufficient to precisely correlate paleoclimatic and archaeological data. It is often difficult, therefore, to estimate to what extent changes in species procurement are correlated with either climate fluctuations or deliberate cultural choices in terms of subsistence behavior. Here, the full development of archeostratigraphy and Bayesian statistical analysis of absolute dates allows the archeological and paleoclimatic chronologies to be compared. The variability in hunted fauna is investigated using multivariate statistical analysis of quantitative faunal lists of 148 assemblages from 39 archeological sequences from MIS 5 through MIS 3. Despite significant intra-technocomplex variability, it is possible to identify major shifts in the human diet during these stages. The integration of archeological data, paleoclimatic proxies and the ecological characteristics of the different species of prey shows that the shifts in large game hunting can be explained by an adaptation of the human groups to climatic fluctuations. However, even if Middle and Early Upper Paleolithic men adapted to changes in their environment and to contrasting landscapes, they ultimately belonged to the ecosystems of the past and were limited by environmental constraints.

  16. Modular Construction of Large Non-Immune Human Antibody Phage-Display Libraries from Variable Heavy and Light Chain Gene Cassettes.

    Science.gov (United States)

    Lee, Nam-Kyung; Bidlingmaier, Scott; Su, Yang; Liu, Bin

    2018-01-01

    Monoclonal antibodies and antibody-derived therapeutics have emerged as a rapidly growing class of biological drugs for the treatment of cancer, autoimmunity, infection, and neurological diseases. To support the development of human antibodies, various display techniques based on antibody gene repertoires have been constructed over the last two decades. In particular, scFv-antibody phage display has been extensively utilized to select lead antibodies against a variety of target antigens. To construct a scFv phage display that enables efficient antibody discovery, and optimization, it is desirable to develop a system that allows modular assembly of highly diverse variable heavy chain and light chain (Vκ and Vλ) repertoires. Here, we describe modular construction of large non-immune human antibody phage-display libraries built on variable gene cassettes from heavy chain and light chain repertoires (Vκ- and Vλ-light can be made into independent cassettes). We describe utility of such libraries in antibody discovery and optimization through chain shuffling.

  17. Gains from quota trade

    DEFF Research Database (Denmark)

    Andersen, Jesper Levring; Bogetoft, Peter

    2007-01-01

    We provide a framework for evaluating potential effects of introducing tradable quotas to a sector. The effects depend on the economies of scale and scope of the production technology, and on firms' ability and willingness to learn best practice methods (catching up) and to change their input...... and output composition (mix). To illustrate our approach, data from the Danish fishery are used to calculate the potential gains from introducing individually transferable fishing quotas. Data envelopment analysis is used to model the production technology. We find that pure reallocation is as important...

  18. Gaining Relational Competitive Advantages

    DEFF Research Database (Denmark)

    Hu, Yimei; Zhang, Si; Li, Jizhen

    2015-01-01

    Establishing strategic technological partnerships (STPs) with foreign partners is an increasingly studied topic within the innovation management literature. Partnering firms can jointly create sources of relational competitive advantage. Chinese firms often lack research and development (R......&D) capabilities but are increasingly becoming preferred technological partners for transnational corporations. We investigate an STP between a Scandinavian and a Chinese firm and try to explore how to gain relational competitive advantage by focusing on its two essential stages: relational rent generation...... and appropriation. Based on an explorative case study, we develop a conceptual framework that consists of process, organizational alliance factors, and coordination modes that we propose lead to relational competitive advantage....

  19. The effect of holiday weight gain on body weight.

    Science.gov (United States)

    Schoeller, Dale A

    2014-07-01

    The topic of holiday weight gain has been a frequent subject of the lay media; however, scientific interest has only been recent. Multiple studies in Western societies have reported average weight gains among adults during the period between mid-November and mid-January that were about 0.5 kg. The range in individual weight changes was large, however, and the already overweight and obese gain more weight than those who are healthy weight. When the average gain across the year was also measured, the holiday weight was the major contributor to annual excess weight gain. Efforts patterned to increase awareness to energy balance and body weight have been shown to be successful at reducing such gain. An exception to holiday weight gain being a major contributor to annual excess gain has been children, in whom summer weight gains have been observed to be the major contributor to average excess weight gain. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. There Is No Further Gain from Calculating Disease Activity Score in 28 Joints with High Sensitivity Assays of C-Reactive Protein Because of High Intraindividual Variability of CRP: A Cross Sectional Study and Theoretical Consideration

    DEFF Research Database (Denmark)

    Jensen Hansen, Inger Marie; Asmussen Andreasen, Rikke; Antonsen, Steen

    Background/Purpose: The threshold for reporting of C-reactive protein (CRP) differs from laboratory to laboratory. Moreover, CRP values are affected by the intra individual biological variability.[1] With respect to disease activity score in 28 joints (DAS28) and Rheumatoid Arthritis (RA), precise...... threshold for reporting CRP is important due to the direct effects of CRP on calculating DAS28, patient classification and subsequent treatment decisions[2] Methods: This study consists of two sections: a theoretical consideration discussing the performance of CRP in calculating DAS28 with regard...... to the biological variation and reporting limit for CRP and a cross sectional study of all RA patients from our department (n=876) applying our theoretical results. In the second section, we calculate DAS28 twice with actual CRP and CRP=9, the latter to elucidate the positive consequences of changing the lower...

  1. There Is No Further Gain from Calculating Disease Activity Score in 28 Joints with High Sensitivity Assays of C-Reactive Protein Because of High Intraindividual Variability of CRP

    DEFF Research Database (Denmark)

    Jensen Hansen, Inger Marie; Asmussen Andreasen, Rikke; Antonsen, Steen

    2016-01-01

    Background/Purpose: The threshold for reporting of C-reactive protein (CRP) differs from laboratory to laboratory. Moreover, CRP values are affected by the intra individual biological variability.[1] With respect to disease activity score in 28 joints (DAS28) and Rheumatoid Arthritis (RA), precise...... threshold for reporting CRP is important due to the direct effects of CRP on calculating DAS28, patient classification and subsequent treatment decisions[2] Methods: This study consists of two sections: a theoretical consideration discussing the performance of CRP in calculating DAS28 with regard...... to the biological variation and reporting limit for CRP and a cross sectional study of all RA patients from our department (n=876) applying our theoretical results. In the second section, we calculate DAS28 twice with actual CRP and CRP=9, the latter to elucidate the positive consequences of changing the lower...

  2. GAIN Technology Workshops Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Braase, Lori Ann [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-08-01

    National and global demand for nuclear energy is increasing and United States (U.S.) global leadership is eroding. There is a sense of urgency with respect to the deployment of the innovative nuclear energy technologies. The Gateway for Accelerated Innovation in Nuclear (GAIN) initiative is based on the simultaneous achievement of three strategic goals. The first is maintaining global technology leadership within the U.S. Department of Energy (DOE). The second is enabling global industrial leadership for nuclear vendors and suppliers. The third is focused on utility optimization of nuclear energy within the clean energy portfolio. An effective public-private partnership is required to achieve these goals. DOEs recognizes the recent sense of urgency new developers and investors have in getting their concepts to market. They know that time to market for nuclear technology takes too long and the facilities needed to conduct the necessary research, development and demonstration (RD&D) activities are very expensive to develop and maintain. Early technologies, in the lower technology readiness levels (TRL) need materials testing, analysis, modeling, code development, etc., most of which currently exists in the DOE national laboratory system. However, mature technologies typically need large component testing and demonstration facilities, which are expensive and long-lead efforts. By understanding the needs of advanced nuclear technology developers, GAIN will connect DOE national laboratory capabilities (e.g., facilities, expertise, materials, and data) with industry RD&D needs. In addition, GAIN is working with the Nuclear Regulatory Commission (NRC) to streamline processes and increase understanding of the licensing requirements for advanced reactors.

  3. GAIN Technology Workshops Summary Report

    International Nuclear Information System (INIS)

    Braase, Lori Ann

    2016-01-01

    National and global demand for nuclear energy is increasing and United States (U.S.) global leadership is eroding. There is a sense of urgency with respect to the deployment of the innovative nuclear energy technologies. The Gateway for Accelerated Innovation in Nuclear (GAIN) initiative is based on the simultaneous achievement of three strategic goals. The first is maintaining global technology leadership within the U.S. Department of Energy (DOE). The second is enabling global industrial leadership for nuclear vendors and suppliers. The third is focused on utility optimization of nuclear energy within the clean energy portfolio. An effective public-private partnership is required to achieve these goals. DOEs recognizes the recent sense of urgency new developers and investors have in getting their concepts to market. They know that time to market for nuclear technology takes too long and the facilities needed to conduct the necessary research, development and demonstration (RD&D) activities are very expensive to develop and maintain. Early technologies, in the lower technology readiness levels (TRL) need materials testing, analysis, modeling, code development, etc., most of which currently exists in the DOE national laboratory system. However, mature technologies typically need large component testing and demonstration facilities, which are expensive and long-lead efforts. By understanding the needs of advanced nuclear technology developers, GAIN will connect DOE national laboratory capabilities (e.g., facilities, expertise, materials, and data) with industry RD&D needs. In addition, GAIN is working with the Nuclear Regulatory Commission (NRC) to streamline processes and increase understanding of the licensing requirements for advanced reactors.

  4. Inter- and intra-storm variability of the isotope composition of precipitation in Southern Israel: Are local or large-scale factors responsible?

    International Nuclear Information System (INIS)

    Gat, J.R.; Adar, E.; Alpert, P.

    2002-01-01

    A detailed sequential rain sampling of rainstorms was carried out during the 1989/90 and 1990/91 rainy season in the coastal plain of Israel with an annual average of 530 mm of rain and in the western Negev where the average annual rainfall is 93 mm. On four occasions, rain was concurrently available at both stations. The variability of the isotope composition within a rainy spell is quite considerable but falls short of the range of isotopic values encountered during the total season. Different rainy episodes show distinguishable isotope compositions, which evidently are characteristic of a larger time/space niche than that of the momentary, local, rain event. This is confirmed by the good correlation between the mean isotope composition of concurrently sampled events at both stations. A 'rain amount effect' is not apparent when the amount-weighted data for each complete rain episode are compared, because any possible effect is masked by the inter-storm variability. However by singling out the data within each storm sequence separately, a moderate effect is seen. On the whole, the results seem to support the notion that the isotope data are determined by the large, synoptic scale, situation. However within the range of values characteristic of the origin of the air masses there is a pronounced dependence of the isotope composition on the extent of the cloud field associated with each event, which is interpreted as a measure of the degree of rainout from the air mass, i.e. a typical Rayleigh effect. Local effects related to momentary rain intensity contribute only to a residual modulation of the above-mentioned effects. (author)

  5. Assessing the variability of glacier lake bathymetries and potential peak discharge based on large-scale measurements in the Cordillera Blanca, Peru

    Science.gov (United States)

    Cochachin, Alejo; Huggel, Christian; Salazar, Cesar; Haeberli, Wilfried; Frey, Holger

    2015-04-01

    .9 km3 while the volume of all glacial lakes of the Cordillera Blanca ranges between 1.15 and 1.29 km3. The small difference in volume of the large lake sample as compared to the smaller sample of bathymetrically surveyed lakes is due to the large size of the measured lakes. The different distributions for lake volume and peak discharge indicate the range of variability in such estimates, and provides valuable first-order information for management and adaptation efforts in the field of water resources and flood prevention.

  6. A Comparison Study between Two MPPT Control Methods for a Large Variable-Speed Wind Turbine under Different Wind Speed Characteristics

    Directory of Open Access Journals (Sweden)

    Dongran Song

    2017-05-01

    Full Text Available Variable speed wind turbines (VSWTs usually adopt a maximum power point tracking (MPPT method to optimize energy capture performance. Nevertheless, obtained performance offered by different MPPT methods may be affected by the impact of wind turbine (WT’s inertia and wind speed characteristics and it needs to be clarified. In this paper, the tip speed ratio (TSR and optimal torque (OT methods are investigated in terms of their performance under different wind speed characteristics on a 1.5 MW wind turbine model. To this end, the TSR control method based on an effective wind speed estimator and the OT control method are firstly presented. Then, their performance is investigated and compared through simulation test results under different wind speeds using Bladed software. Comparison results show that the TSR control method can capture slightly more wind energy at the cost of high component loads than the other one under all wind conditions. Furthermore, it is found that both control methods present similar trends of power reduction that is relevant to mean wind speed and turbulence intensity. From the obtained results, we demonstrate that, to further improve MPPT capability of large VSWTs, other advanced control methods using wind speed prediction information need to be addressed.

  7. Acting to gain information

    Science.gov (United States)

    Rosenchein, Stanley J.; Burns, J. Brian; Chapman, David; Kaelbling, Leslie P.; Kahn, Philip; Nishihara, H. Keith; Turk, Matthew

    1993-01-01

    This report is concerned with agents that act to gain information. In previous work, we developed agent models combining qualitative modeling with real-time control. That work, however, focused primarily on actions that affect physical states of the environment. The current study extends that work by explicitly considering problems of active information-gathering and by exploring specialized aspects of information-gathering in computational perception, learning, and language. In our theoretical investigations, we analyzed agents into their perceptual and action components and identified these with elements of a state-machine model of control. The mathematical properties of each was developed in isolation and interactions were then studied. We considered the complexity dimension and the uncertainty dimension and related these to intelligent-agent design issues. We also explored active information gathering in visual processing. Working within the active vision paradigm, we developed a concept of 'minimal meaningful measurements' suitable for demand-driven vision. We then developed and tested an architecture for ongoing recognition and interpretation of visual information. In the area of information gathering through learning, we explored techniques for coping with combinatorial complexity. We also explored information gathering through explicit linguistic action by considering the nature of conversational rules, coordination, and situated communication behavior.

  8. Leading Gainful Employment Metric Reporting

    Science.gov (United States)

    Powers, Kristina; MacPherson, Derek

    2016-01-01

    This chapter will address the importance of intercampus involvement in reporting of gainful employment student-level data that will be used in the calculation of gainful employment metrics by the U.S. Department of Education. The authors will discuss why building relationships within the institution is critical for effective gainful employment…

  9. Large proportions of overweight and obese children, as well as their parents, underestimate children's weight status across Europe. The ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) project.

    Science.gov (United States)

    Manios, Yannis; Moschonis, George; Karatzi, Kalliopi; Androutsos, Odysseas; Chinapaw, Mai; Moreno, Luis A; Bere, Elling; Molnar, Denes; Jan, Natasha; Dössegger, Alain; De Bourdeaudhuij, Ilse; Singh, Amika; Brug, Johannes

    2015-08-01

    To investigate the magnitude and country-specific differences in underestimation of children's weight status by children and their parents in Europe and to further explore its associations with family characteristics and sociodemographic factors. Children's weight and height were objectively measured. Parental anthropometric and sociodemographic data were self-reported. Children and their parents were asked to comment on children's weight status based on five-point Likert-type scales, ranging from 'I am much too thin' to 'I am much too fat' (children) and 'My child's weight is way too little' to 'My child's weight is way too much' (parents). These data were combined with children's actual weight status, in order to assess underestimation of children's weight status by children themselves and by their parents, respectively. Chi-square tests and multilevel logistic regression analyses were conducted to examine the aims of the current study. Eight European countries participating in the ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) project. A school-based survey among 6113 children aged 10-12 years and their parents. In the total sample, 42·9 % of overweight/obese children and 27·6 % of parents of overweight/obese children underestimated their and their children's weight status, respectively. A higher likelihood for this underestimation of weight status by children and their parents was observed in Eastern and Southern compared with Central/Northern countries. Overweight or obese parents (OR=1·81; 95 % CI 1·39, 2·35 and OR=1·78, 95 % CI 1·22, 2·60), parents of boys (OR=1·32; 95 % CI 1·05, 1·67) and children from overweight/obese (OR=1·60; 95 % CI 1·29, 1·98 and OR=1·76; 95 % CI 1·29, 2·41) or unemployed parents (OR=1·53; 95 % CI 1·22, 1·92) were more likely to underestimate children's weight status. Children of overweight or obese parents, those from Eastern and Southern Europe, boys, younger children and

  10. The Biology of Intron Gain and Loss

    DEFF Research Database (Denmark)

    Jeffares, Daniel C; Mourier, Tobias; Penny, David

    2006-01-01

    Intron density in eukaryote genomes varies by more than three orders of magnitude, so there must have been extensive intron gain and/or intron loss during evolution. A favored and partial explanation for this range of intron densities has been that introns have accumulated stochastically in large...... on introns depending on the biology of the organism and the gene involved....

  11. Leaving home for college and gaining independence

    NARCIS (Netherlands)

    Mulder, C.H.; Clark, W.A.V.

    2002-01-01

    As more and more young US adults attend college it has become an increasingly important filter in the process of becoming an independent household. Now for a large number of young adults living in the USA, living away at college is a first step in the process of gaining residential and economic

  12. Potential gains from hospital mergers in Denmark.

    Science.gov (United States)

    Kristensen, Troels; Bogetoft, Peter; Pedersen, Kjeld Moeller

    2010-12-01

    The Danish hospital sector faces a major rebuilding program to centralize activity in fewer and larger hospitals. We aim to conduct an efficiency analysis of hospitals and to estimate the potential cost savings from the planned hospital mergers. We use Data Envelopment Analysis (DEA) to estimate a cost frontier. Based on this analysis, we calculate an efficiency score for each hospital and estimate the potential gains from the proposed mergers by comparing individual efficiencies with the efficiency of the combined hospitals. Furthermore, we apply a decomposition algorithm to split merger gains into technical efficiency, size (scale) and harmony (mix) gains. The motivation for this decomposition is that some of the apparent merger gains may actually be available with less than a full-scale merger, e.g., by sharing best practices and reallocating certain resources and tasks. Our results suggest that many hospitals are technically inefficient, and the expected "best practice" hospitals are quite efficient. Also, some mergers do not seem to lower costs. This finding indicates that some merged hospitals become too large and therefore experience diseconomies of scale. Other mergers lead to considerable cost reductions; we find potential gains resulting from learning better practices and the exploitation of economies of scope. To ensure robustness, we conduct a sensitivity analysis using two alternative returns-to-scale assumptions and two alternative estimation approaches. We consistently find potential gains from improving the technical efficiency and the exploitation of economies of scope from mergers.

  13. Aerodynamic Effects of High Turbulence Intensity on a Variable-Speed Power-Turbine Blade With Large Incidence and Reynolds Number Variations

    Science.gov (United States)

    Flegel, Ashlie B.; Giel, Paul W.; Welch, Gerard E.

    2014-01-01

    The effects of high inlet turbulence intensity on the aerodynamic performance of a variable speed power turbine blade are examined over large incidence and Reynolds number ranges. These results are compared to previous measurements made in a low turbulence environment. Both high and low turbulence studies were conducted in the NASA Glenn Research Center Transonic Turbine Blade Cascade Facility. The purpose of the low inlet turbulence study was to examine the transitional flow effects that are anticipated at cruise Reynolds numbers. The current study extends this to LPT-relevant turbulence levels while perhaps sacrificing transitional flow effects. Assessing the effects of turbulence at these large incidence and Reynolds number variations complements the existing database. Downstream total pressure and exit angle data were acquired for 10 incidence angles ranging from +15.8deg to -51.0deg. For each incidence angle, data were obtained at five flow conditions with the exit Reynolds number ranging from 2.12×10(exp 5) to 2.12×10(exp 6) and at a design exit Mach number of 0.72. In order to achieve the lowest Reynolds number, the exit Mach number was reduced to 0.35 due to facility constraints. The inlet turbulence intensity, Tu, was measured using a single-wire hotwire located 0.415 axial-chord upstream of the blade row. The inlet turbulence levels ranged from 8 to 15 percent for the current study. Tu measurements were also made farther upstream so that turbulence decay rates could be calculated as needed for computational inlet boundary conditions. Downstream flow field measurements were obtained using a pneumatic five-hole pitch/yaw probe located in a survey plane 7 percent axial chord aft of the blade trailing edge and covering three blade passages. Blade and endwall static pressures were acquired for each flow condition as well. The blade loading data show that the suction surface separation that was evident at many of the low Tu conditions has been eliminated. At

  14. Variability in clinical prevalence of PaV1 in Caribbean spiny lobsters occupying commercial casitas over a large bay in Mexico.

    Science.gov (United States)

    Candia-Zulbarán, Rebeca I; Briones-Fourzán, Patricia; Negrete-Soto, Fernando; Barradas-Ortiz, Cecilia; Lozano-Álvarez, Enrique

    2012-08-27

    In Bahía de la Ascensión, Mexico, the fishery for spiny lobsters Panulirus argus is based on the extensive use of casitas, large artificial shelters that can harbor the full size range of these highly gregarious lobsters. The discovery of a pathogenic virus in these lobsters (Panulirus argus virus 1, or PaV1) has raised concern about its potential effects on casita-based fisheries. Because in Bahía de la Ascensión visibly infected lobsters represent an immediate loss of revenue, we examined variability in clinical prevalence of PaV1 (percentage of lobsters visibly infected) in thousands of lobsters sampled from the commercial catch at the onset of 3 consecutive fishing years, and from 530 casitas distributed over 3 zones within the bay during 2 fishing and 2 closed seasons. In the commercial catch (lobsters 67 to 147 mm carapace length [CL]), clinical prevalence of PaV1 was low and was not affected by year or sex. In lobsters (9.2 to 115.0 mm CL) that occupied casitas, clinical prevalence of PaV1 varied with sampling season and was always higher in juveniles than in subadults or adults, but was consistently lower in one zone relative to the other 2 zones. The average clinical prevalence of PaV1 in this bay was statistically similar to the average clinical prevalence reported in Cuba, where casitas are also used, and in Florida Bay, USA, where casitas are not used. To date, PaV1 has had no discernible impact on the lobster fishery in Bahía de la Ascensión, suggesting that clinical prevalence is not influenced by the use of casitas per se.

  15. Immunoglobulin Heavy Chain Variable Region and Major Histocompatibility Region Genes Are Linked to Induced Graves' Disease in Females From Two Very Large Families of Recombinant Inbred Mice

    Science.gov (United States)

    Aliesky, Holly; Banuelos, Bianca; Magana, Jessica; Williams, Robert W.; Rapoport, Basil

    2014-01-01

    Graves' hyperthyroidism is caused by antibodies to the TSH receptor (TSHR) that mimic thyroid stimulation by TSH. Stimulating TSHR antibodies and hyperthyroidism can be induced by immunizing mice with adenovirus expressing the human TSHR A-subunit. Prior analysis of induced Graves' disease in small families of recombinant inbred (RI) female mice demonstrated strong genetic control but did not resolve trait loci for TSHR antibodies or elevated serum T4. We investigated the genetic basis for induced Graves' disease in female mice of two large RI families and combined data with earlier findings to provide phenotypes for 178 genotypes. TSHR antibodies measured by inhibition of TSH binding to its receptor were highly significantly linked in the BXD set to the major histocompatibility region (chromosome 17), consistent with observations in 3 other RI families. In the LXS family, we detected linkage between T4 levels after TSHR-adenovirus immunization and the Ig heavy chain variable region (Igvh, chromosome 12). This observation is a key finding because components of the antigen binding region of Igs determine antibody specificity and have been previously linked to induced thyroid-stimulating antibodies. Data from the LXS family provide the first evidence in mice of a direct link between induced hyperthyroidism and Igvh genes. A role for major histocompatibility genes has now been established for genetic susceptibility to Graves' disease in both humans and mice. Future studies using arrays incorporating variation in the complex human Ig gene locus will be necessary to determine whether Igvh genes are also linked to Graves' disease in humans. PMID:25051451

  16. SU-E-T-230: Creating a Large Number of Focused Beams with Variable Patient Head Tilt to Improve Dose Fall-Off for Brain Radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, J; Ma, L [Department of Radiation Oncology, University of California San Francisco School of Medicine, San Francisco, CA (United States)

    2015-06-15

    Purpose: To develop a treatment delivery and planning strategy by increasing the number of beams to minimize dose to brain tissue surrounding a target, while maximizing dose coverage to the target. Methods: We analyzed 14 different treatment plans via Leksell PFX and 4C. For standardization, single tumor cases were chosen. Original treatment plans were compared with two optimized plans. The number of beams was increased in treatment plans by varying tilt angles of the patient head, while maintaining original isocenter and the beam positions in the x-, y- and z-axes, collimator size, and beam blocking. PFX optimized plans increased beam numbers with three pre-set tilt angles, 70, 90, 110, and 4C optimized plans increased beam numbers with tilt angles increasing arbitrarily from range of 30 to 150 degrees. Optimized treatment plans were compared dosimetrically with original treatment plans. Results: Comparing total normal tissue isodose volumes between original and optimized plans, the low-level percentage isodose volumes decreased in all plans. Despite the addition of multiple beams up to a factor of 25, beam-on times for 1 tilt angle versus 3 or more tilt angles were comparable (<1 min.). In 64% (9/14) of the studied cases, the volume percentage decrease by >5%, with the highest value reaching 19%. The addition of more tilt angles correlates to a greater decrease in normal brain irradiated volume. Selectivity and coverage for original and optimized plans remained comparable. Conclusion: Adding large number of additional focused beams with variable patient head tilt shows improvement for dose fall-off for brain radiosurgery. The study demonstrates technical feasibility of adding beams to decrease target volume.

  17. SU-E-T-230: Creating a Large Number of Focused Beams with Variable Patient Head Tilt to Improve Dose Fall-Off for Brain Radiosurgery

    International Nuclear Information System (INIS)

    Chiu, J; Ma, L

    2015-01-01

    Purpose: To develop a treatment delivery and planning strategy by increasing the number of beams to minimize dose to brain tissue surrounding a target, while maximizing dose coverage to the target. Methods: We analyzed 14 different treatment plans via Leksell PFX and 4C. For standardization, single tumor cases were chosen. Original treatment plans were compared with two optimized plans. The number of beams was increased in treatment plans by varying tilt angles of the patient head, while maintaining original isocenter and the beam positions in the x-, y- and z-axes, collimator size, and beam blocking. PFX optimized plans increased beam numbers with three pre-set tilt angles, 70, 90, 110, and 4C optimized plans increased beam numbers with tilt angles increasing arbitrarily from range of 30 to 150 degrees. Optimized treatment plans were compared dosimetrically with original treatment plans. Results: Comparing total normal tissue isodose volumes between original and optimized plans, the low-level percentage isodose volumes decreased in all plans. Despite the addition of multiple beams up to a factor of 25, beam-on times for 1 tilt angle versus 3 or more tilt angles were comparable (<1 min.). In 64% (9/14) of the studied cases, the volume percentage decrease by >5%, with the highest value reaching 19%. The addition of more tilt angles correlates to a greater decrease in normal brain irradiated volume. Selectivity and coverage for original and optimized plans remained comparable. Conclusion: Adding large number of additional focused beams with variable patient head tilt shows improvement for dose fall-off for brain radiosurgery. The study demonstrates technical feasibility of adding beams to decrease target volume

  18. Hydrogen gains further momentum

    International Nuclear Information System (INIS)

    Anon.

    2017-01-01

    As first industrial production projects should become a reality in the next few years, hydrogen as a source of energy will find important applications with mobility, which momentum is rapid and irresistible. Next steps will be the (large capacity) storage of hydrogen associated to power-to-gas systems and the generalization of renewable energies. This document presents 5 articles, which themes are: Description and explanation of the process of hydrogen production; Presentation of the H2V project for the construction, in Normandy, of the first operational industrial hydrogen production plant using electric power 100 pc generated by renewable energies; The conversion of electric power from renewable energies through hydrogen storage and fuel cells for buildings applications (Sylfen project); The development of a reversible fuel cell at Mines-Paris Tech University, that will be adapted to the storage of renewable electric power; Hydrogen as a lever for the development of zero-emission vehicles, from trucks to cars and bicycles

  19. Behavioral Treatment Approaches to Prevent Weight Gain Following Smoking Cessation.

    Science.gov (United States)

    Grinstead, Olga A.

    Personality and physiological, cognitive, and environmental factors have all been suggested as critical variables in smoking cessation and relapse. Weight gain and the fear of weight gain after smoking cessation may also prevent many smokers from quitting. A sample of 45 adult smokers participated in a study in which three levels of preventive…

  20. When size matters: attention affects performance by contrast or response gain.

    Science.gov (United States)

    Herrmann, Katrin; Montaser-Kouhsari, Leila; Carrasco, Marisa; Heeger, David J

    2010-12-01

    Covert attention, the selective processing of visual information in the absence of eye movements, improves behavioral performance. We found that attention, both exogenous (involuntary) and endogenous (voluntary), can affect performance by contrast or response gain changes, depending on the stimulus size and the relative size of the attention field. These two variables were manipulated in a cueing task while stimulus contrast was varied. We observed a change in behavioral performance consonant with a change in contrast gain for small stimuli paired with spatial uncertainty and a change in response gain for large stimuli presented at one location (no uncertainty) and surrounded by irrelevant flanking distracters. A complementary neuroimaging experiment revealed that observers' attention fields were wider with than without spatial uncertainty. Our results support important predictions of the normalization model of attention and reconcile previous, seemingly contradictory findings on the effects of visual attention.

  1. Weight suppression predicts total weight gain and rate of weight gain in outpatients with anorexia nervosa.

    Science.gov (United States)

    Carter, Frances A; Boden, Joseph M; Jordan, Jennifer; McIntosh, Virginia V W; Bulik, Cynthia M; Joyce, Peter R

    2015-11-01

    The present study sought to replicate the finding of Wildes and Marcus, Behav Res Ther, 50, 266-274, 2012 that higher levels of weight suppression at pretreatment predict greater total weight gain, faster rate of weight gain, and bulimic symptoms amongst patients admitted with anorexia nervosa. Participants were 56 women with anorexia nervosa diagnosed by using strict or lenient weight criteria, who were participating in a randomized controlled psychotherapy trial (McIntosh et al., Am J Psychiatry, 162, 741-747, 2005). Thirty-five women completed outpatient treatment and post-treatment assessment. Weight suppression was the discrepancy between highest lifetime weight at adult height and weight at pretreatment assessment. Outcome variables were total weight gain, rate of weight gain, and bulimic symptoms in the month prior to post-treatment assessment [assessed using the Eating Disorders Examination (Fairburn et al., Binge-Eating: Nature, Assessment and Treatment. New York: Guilford, 1993)]. Weight suppression was positively associated with total weight gain and rate of weight gain over treatment. Regression models showed that this association could not be explained by covariates (age at onset of anorexia nervosa and treatment modality). Weight suppression was not significantly associated with bulimic symptoms in the month prior to post-treatment assessment, regardless of whether bulimic symptoms were examined as continuous or dichotomous variables. The present study reinforces the previous finding that weight suppression predicts total weight gain and rate of weight gain amongst patients being treated for anorexia nervosa. Methodological issues may explain the failure of the present study to find that weight suppression predicts bulimic symptoms. Weight suppression at pretreatment for anorexia nervosa should be assessed routinely and may inform treatment planning. © 2015 Wiley Periodicals, Inc.

  2. Identifying barriers to large-scale integration of variable renewable electricity into the electricity market : A literature review of market design

    NARCIS (Netherlands)

    Hu, J.; Harmsen, R.; Crijns-Graus, Wina; Worrell, E.; van den Broek, M.A.

    For reaching the 2 °C climate target, the robust growth of electricity generation from variable renewable energy sources (VRE) in the power sector is expected to continue. Accommodation of the power system to the variable, uncertain and locational-dependent outputs of VRE causes integration costs.

  3. Analysis of the Latitudinal Variability of Tropospheric Ozone in the Arctic Using the Large Number of Aircraft and Ozonesonde Observations in Early Summer 2008

    Science.gov (United States)

    Ancellet, Gerard; Daskalakis, Nikos; Raut, Jean Christophe; Quennehen, Boris; Ravetta, Francois; Hair, Jonathan; Tarasick, David; Schlager, Hans; Weinheimer, Andrew J.; Thompson, Anne M.; hide

    2016-01-01

    The goal of the paper are to: (1) present tropospheric ozone (O3) climatologies in summer 2008 based on a large amount of measurements, during the International Polar Year when the Polar Study using Aircraft, Remote Sensing, Surface Measurements, and Models of Climate Chemistry, Aerosols, and Transport (POLARCAT) campaigns were conducted (2) investigate the processes that determine O3 concentrations in two different regions (Canada and Greenland) that were thoroughly studied using measurements from 3 aircraft and 7 ozonesonde stations. This paper provides an integrated analysis of these observations and the discussion of the latitudinal and vertical variability of tropospheric ozone north of 55oN during this period is performed using a regional model (WFR-Chem). Ozone, CO and potential vorticity (PV) distributions are extracted from the simulation at the measurement locations. The model is able to reproduce the O3 latitudinal and vertical variability but a negative O3 bias of 6-15 ppbv is found in the free troposphere over 4 km, especially over Canada. Ozone average concentrations are of the order of 65 ppbv at altitudes above 4 km both over Canada and Greenland, while they are less than 50 ppbv in the lower troposphere. The relative influence of stratosphere-troposphere exchange (STE) and of ozone production related to the local biomass burning (BB) emissions is discussed using differences between average values of O3, CO and PV for Southern and Northern Canada or Greenland and two vertical ranges in the troposphere: 0-4 km and 4-8 km. For Canada, the model CO distribution and the weak correlation (less than 30%) of O3 and PV suggests that stratosphere troposphere exchange (STE) is not the major contribution to average tropospheric ozone at latitudes less than 70 deg N, due to the fact that local biomass burning (BB) emissions were significant during the 2008 summer period. Conversely over Greenland, significant STE is found according to the better O3 versus PV

  4. A study to solve the variability of wind generation through integration of large-scale hydraulic generation; Um estudo para resolver a variabilidade da geracao eolica atraves da integracao em larga escala com geracao hidraulica

    Energy Technology Data Exchange (ETDEWEB)

    Emmerik, Emanuel Leonardus van; Steinberger, Johann Michael; Aredes, Mauricio [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEE/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Eletrica

    2010-07-01

    The optimal deployment of wind generation with the hydro generation is being investigated as a viable option to assist in resolving the constraints coming ahead as a consequence of the tendency of recovery in the Brazilian Amazon basin for expansion of generating facilities. It is in the validity of this research that this work is focused. The value is shown of feasibility studies of using water power generation to offset the variability of wind generation when it is deployed on a large scale. Preliminary results are presented for the variability of wind generation at various cycles, the variability of the availability of hydropower. (author)

  5. Operational gain : measuring the capture of genetic gain ...

    African Journals Online (AJOL)

    The concept of operational gain is more than the weighted average of the genetic quality of planted hectares, and encompasses tree breeding efficiencies, propagation efficiencies, matching of species and genotype to site, plant use efficiency and early measures of stand density and growth. To test the operational gain ...

  6. Assessing temporal and spatial variability of phytoplankton composition in a large reservoir in the Brazilian northeastern region under intense drought conditions

    Directory of Open Access Journals (Sweden)

    Hortência de Souza Barroso

    2017-11-01

    Full Text Available The present study was carried out in Castanhão Reservoir, a large aquatic system in the Brazilian semi-arid region that serves multiples uses as water drinking supply and intensive fish-cage aquaculture site. In order to understand the effects of environmental conditions on the spatial and temporal variability of the phytoplankton functional groups (FG and the main ‘characterizing taxa’, sub-superficial water samples were collected from March 2012 to August 2013, a period distinguished by the continuous drop in reservoir volume due to rainfall shortage. Eighteen functional groups and 102 total phytoplankton taxa were found in the Castanhão reservoir during the study. No significant differences were observed relative to spatial variation of total phytoplankton composition throughout the reservoir (PERMANOVA, P>0.05. On the other hand, according to cluster analysis results, three temporal phases have been identified (Similarity Profile, P<0.05, based on 102 phytoplankton taxa. The ‘characterizing taxa’ was found using the Similarity Percentage procedure (cut-off 90%, being thus defined as those taxa that contributed the most to the similarity within each temporal phase. Nineteen ‘characterizing taxa’ described the Castanhão reservoir, with predominance of those typical of mixing and turbidity conditions. Cyanobacteria dominated through the three temporal phases. According to the redundancy analysis, nutrient availability and water transparency were found to influence the phytoplankton temporal dynamics. The phase I (rainy season was most represented by Planktolyngbya minor/Pl. limnetica (FG = S1, which reached best performance under strongly decreased phosphate-P concentrations and low water transparency. In phase II (dry season, Romeria victoriae (FG = ? outcompeted other cyanobacteria probably due the increase in water transparency and decrease in ammonium-N. Finally, in phase III (rainy season the decrease of water transparency

  7. Molecular analysis of immunoglobulin variable genes supports a germinal center experienced normal counterpart in primary cutaneous diffuse large B-cell lymphoma, leg-type.

    Science.gov (United States)

    Pham-Ledard, Anne; Prochazkova-Carlotti, Martina; Deveza, Mélanie; Laforet, Marie-Pierre; Beylot-Barry, Marie; Vergier, Béatrice; Parrens, Marie; Feuillard, Jean; Merlio, Jean-Philippe; Gachard, Nathalie

    2017-11-01

    Immunophenotype of primary cutaneous diffuse large B-cell lymphoma, leg-type (PCLBCL-LT) suggests a germinal center-experienced B lymphocyte (BCL2+ MUM1+ BCL6+/-). As maturation history of B-cell is "imprinted" during B-cell development on the immunoglobulin gene sequence, we studied the structure and sequence of the variable part of the genes (IGHV, IGLV, IGKV), immunoglobulin surface expression and features of class switching in order to determine the PCLBCL-LT cell of origin. Clonality analysis with BIOMED2 protocol and VH leader primers was done on DNA extracted from frozen skin biopsies on retrospective samples from 14 patients. The clonal DNA IGHV sequence of the tumor was aligned and compared with the closest germline sequence and homology percentage was calculated. Superantigen binding sites were studied. Features of selection pressure were evaluated with the multinomial Lossos model. A functional monoclonal sequence was observed in 14 cases as determined for IGHV (10), IGLV (2) or IGKV (3). IGV mutation rates were high (>5%) in all cases but one (median:15.5%), with superantigen binding sites conservation. Features of selection pressure were identified in 11/12 interpretable cases, more frequently negative (75%) than positive (25%). Intraclonal variation was detected in 3 of 8 tumor specimens with a low rate of mutations. Surface immunoglobulin was an IgM in 12/12 cases. FISH analysis of IGHM locus, deleted during class switching, showed heterozygous IGHM gene deletion in half of cases. The genomic PCR analysis confirmed the deletions within the switch μ region. IGV sequences were highly mutated but functional, with negative features of selection pressure suggesting one or more germinal center passage(s) with somatic hypermutation, but superantigen (SpA) binding sites conservation. Genetic features of class switch were observed, but on the non functional allele and co-existing with primary isotype IgM expression. These data suggest that cell-of origin is

  8. Disability as deprivation of capabilities: Estimation using a large-scale survey in Morocco and Tunisia and an instrumental variable approach.

    Science.gov (United States)

    Trani, Jean-Francois; Bakhshi, Parul; Brown, Derek; Lopez, Dominique; Gall, Fiona

    2018-05-25

    The capability approach pioneered by Amartya Sen and Martha Nussbaum offers a new paradigm to examine disability, poverty and their complex associations. Disability is hence defined as a situation in which a person with an impairment faces various forms of restrictions in functionings and capabilities. Additionally, poverty is not the mere absence of income but a lack of ability to achieve essential functionings; disability is consequently the poverty of capabilities of persons with impairment. It is the lack of opportunities in a given context and agency that leads to persons with disabilities being poorer than other social groups. Consequently, poverty of people with disabilities comprises of complex processes of social exclusion and disempowerment. Despite growing evidence that persons with disabilities face higher levels of poverty, the literature from low and middle-income countries that analyzes the causal link between disability and poverty, remains limited. Drawing on data from a large case control field survey carried out between December 24th , 2013 and February 16th , 2014 in Tunisia and between November 4th , 2013 and June 12th , 2014 in Morocco, we examined the effect of impairment on various basic capabilities, health related quality of life and multidimensional poverty - indicators of poor wellbeing-in Morocco and Tunisia. To demonstrate a causal link between impairment and deprivation of capabilities, we used instrumental variable regression analyses. In both countries, we found lower access to jobs for persons with impairment. Health related quality of life was also lower for this group who also faced a higher risk of multidimensional poverty. There was no significant direct effect of impairment on access to school and acquiring literacy in both countries, and on access to health care and expenses in Tunisia, while having an impairment reduced access to healthcare facilities in Morocco and out of pocket expenditures. These results suggest that

  9. Aerodynamic Effects of Turbulence Intensity on a Variable-Speed Power-Turbine Blade with Large Incidence and Reynolds Number Variations

    Science.gov (United States)

    Flegel, Ashlie Brynn; Giel, Paul W.; Welch, Gerard E.

    2014-01-01

    The effects of inlet turbulence intensity on the aerodynamic performance of a variable speed power turbine blade are examined over large incidence and Reynolds number ranges. Both high and low turbulence studies were conducted in the NASA Glenn Research Center Transonic Turbine Blade Cascade Facility. The purpose of the low inlet turbulence study was to examine the transitional flow effects that are anticipated at cruise Reynolds numbers. The high turbulence study extends this to LPT-relevant turbulence levels while perhaps sacrificing transitional flow effects. Downstream total pressure and exit angle data were acquired for ten incidence angles ranging from +15.8 to 51.0. For each incidence angle, data were obtained at five flow conditions with the exit Reynolds number ranging from 2.12105 to 2.12106 and at a design exit Mach number of 0.72. In order to achieve the lowest Reynolds number, the exit Mach number was reduced to 0.35 due to facility constraints. The inlet turbulence intensity, Tu, was measured using a single-wire hotwire located 0.415 axial-chord upstream of the blade row. The inlet turbulence levels ranged from 0.25 - 0.4 for the low Tu tests and 8- 15 for the high Tu study. Tu measurements were also made farther upstream so that turbulence decay rates could be calculated as needed for computational inlet boundary conditions. Downstream flow field measurements were obtained using a pneumatic five-hole pitchyaw probe located in a survey plane 7 axial chord aft of the blade trailing edge and covering three blade passages. Blade and endwall static pressures were acquired for each flow condition as well. The blade loading data show that the suction surface separation that was evident at many of the low Tu conditions has been eliminated. At the extreme positive and negative incidence angles, the data show substantial differences in the exit flow field. These differences are attributable to both the higher inlet Tu directly and to the thinner inlet endwall

  10. Capital Gains Taxation and House Price Fluctuations

    DEFF Research Database (Denmark)

    Fuest, Clemens; Nielsen, Søren Bo

    2004-01-01

    Recent years have seen large swings in house prices in many countries. Motivated by housing price variations, proposals for taxing capital gains on housing have repeatedly been put forth. The idea seems to be that such taxes would curb the redistribution occurring between those owning houses...... and those trying to get into the market for owner-occupied housing. Our paper shows that at least in simple settings, a tax on real capital gains on housing will only lead to even bigger price swings and will not be able to redistribute between people appearing on either side of the housing market.......Keywords: capital gains tax, housing market, price fluctuationsJEL-Classification: H23, H24, R 31.Addresses:...

  11. Accounting for Unresolved Spatial Variability in Large Scale Models: Development and Evaluation of a Statistical Cloud Parameterization with Prognostic Higher Order Moments

    Energy Technology Data Exchange (ETDEWEB)

    Robert Pincus

    2011-05-17

    This project focused on the variability of clouds that is present across a wide range of scales ranging from the synoptic to the millimeter. In particular, there is substantial variability in cloud properties at scales smaller than the grid spacing of models used to make climate projections (GCMs) and weather forecasts. These models represent clouds and other small-scale processes with parameterizations that describe how those processes respond to and feed back on the largescale state of the atmosphere.

  12. High Gain Advanced GPS Receiver

    National Research Council Canada - National Science Library

    Brown, Alison; Zhang, Gengsheng

    2006-01-01

    NAVSYS High Gain Advanced GPS Receiver (HAGR) uses a digital beam-steering antenna array to enable up to eight GPS satellites to be tracked, each with up to 10 dBi of additional antenna gain over a conventional receiver solution...

  13. Short sleep duration and large variability in sleep duration are independently associated with dietary risk factors for obesity in Danish school children

    DEFF Research Database (Denmark)

    Kjeldsen, J S; Hjorth, M F; Andersen, Rikke

    2014-01-01

    Background:Lack of sleep and increased consumption of energy-dense foods and sugar-sweetened beverages (SSB) have all been suggested as factors contributing to the increased prevalence of overweight and obesity.Objective:To evaluate whether objectively measured sleep duration (average and day......-to-day variability) as well as parent-reported sleep problems are independently associated with proposed dietary risk factors for overweight and obesity in 8-11 year old children.Design:In this cross-sectional study data on sleep duration and day-to-day variability in sleep duration were measured in 676 Danish...... and ethnicity).Conclusion:Our study suggests that short sleep duration, high sleep duration variability, and experiencing sleep problems are all associated with a poor, obesity-promoting diet in children.International Journal of Obesity accepted article preview online, 8 August 2013. doi:10.1038/ijo.2013.147....

  14. Will we be heating with green electricity tomorrow? The large potential of load-variable private customer tariffs; Heizen wir kuenftig mit Oekostrom? Das grosse Potenzial lastvariabler Privatkundentarife

    Energy Technology Data Exchange (ETDEWEB)

    Zierdt, Tobias; Lang, Dirk [RWE Effizienz GmbH, Dortmund (Germany)

    2012-09-15

    Momentous changes loom ahead for Germany's energy supply system as a result of the energy turnaround. One central question is how load peaks from renewable energy plants can be conveniently accommodated on the demand side. Two research projects are currently being carried out to examine the acceptance of time-variable and load-variable tariffs for private households. First results show that using green electricity for heat generation is significantly more attractive for both customers and energy suppliers than using it to cover day-to-day electricity demand at a later time.

  15. Large-scale studies of the HphI insulin gene variable-number-of-tandem-repeats polymorphism in relation to Type 2 diabetes mellitus and insulin release

    DEFF Research Database (Denmark)

    Hansen, S K; Gjesing, A P; Rasmussen, S K

    2004-01-01

    The class III allele of the variable-number-of-tandem-repeats polymorphism located 5' of the insulin gene (INS-VNTR) has been associated with Type 2 diabetes and altered birthweight. It has also been suggested, although inconsistently, that the class III allele plays a role in glucose-induced ins......The class III allele of the variable-number-of-tandem-repeats polymorphism located 5' of the insulin gene (INS-VNTR) has been associated with Type 2 diabetes and altered birthweight. It has also been suggested, although inconsistently, that the class III allele plays a role in glucose...

  16. Terrestrial Ecosystem Responses to Species Gains and Losses

    NARCIS (Netherlands)

    Wardle, D.A.; Bardgett, R.D.; Callaway, R.; Putten, van der W.H.

    2011-01-01

    Ecosystems worldwide are losing some species and gaining others, resulting in an interchange of species that is having profound impacts on how these ecosystems function. However, research on the effects of species gains and losses has developed largely independently of one another. Recent conceptual

  17. Terrestrial ecosystem responses to species gains and losses

    NARCIS (Netherlands)

    Wardle, D.A.; Bardgett, R.D.; Callaway, R.M.; Van der Putten, W.H.

    2011-01-01

    Ecosystems worldwide are losing some species and gaining others, resulting in an interchange of species that is having profound impacts on how these ecosystems function. However, research on the effects of species gains and losses has developed largely independently of one another. Recent conceptual

  18. Fluctuations in the large-scale atmospheric circulation and ocean conditions associated with the dominant modes of wintertime precipitation variability for the contiguous United States

    International Nuclear Information System (INIS)

    Mitchell, T.P.; Blier, W.

    1994-01-01

    The historical Climatic Division record of monthly- and seasonal-mean wintertime precipitation totals are analyzed to document the dominant patterns of precipitation variability for the contiguous United States. The analysis technique employed is the Rotated Principal Component analysis. Time series for the leading patterns are related to global sea-surface temperatures (SSTs), and to gridded surface and upper-air analyses for the Northern Hemisphere

  19. Developmental gains in visuospatial memory predict gains in mathematics achievement.

    Science.gov (United States)

    Li, Yaoran; Geary, David C

    2013-01-01

    Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning.

  20. Developmental gains in visuospatial memory predict gains in mathematics achievement.

    Directory of Open Access Journals (Sweden)

    Yaoran Li

    Full Text Available Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4 were larger than gains in the capacity of the central executive (d = 1.6 that in turn were larger than gains in phonological memory span (d = 1.1. First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning.

  1. Developmental Gains in Visuospatial Memory Predict Gains in Mathematics Achievement

    Science.gov (United States)

    Li, Yaoran; Geary, David C.

    2013-01-01

    Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning. PMID:23936154

  2. A wide range and high speed automatic gain control

    International Nuclear Information System (INIS)

    Tacconi, E.; Christiansen, C.

    1993-05-01

    Automatic gain control (AGC) techniques have been largely used since the beginning of electronics, but in most of the applications the dynamic response is slow compared with the carrier frequency. The problem of developing an automatic gain control with high dynamic response and wide control range simultaneously is analyzed in this work. An ideal gain control law, with the property that the total loop gain remains constant independent of the carrier amplitude, is obtained. The resulting AGC behavior is compared by computer simulations with a linear multiplier AGC. The ideal gain control law can be approximated using a transconductance amplifier. A practical circuit that has been used at CERN in the radio frequency loops of the Booster Synchrotron is presented. The circuit has high speed and 80-dB gain control range

  3. Windfall gains, political economy and economic development

    DEFF Research Database (Denmark)

    Dalgaard, Carl-Johan Lars; Olsson, Ola

    2008-01-01

    Natural resource rents and foreign aid have the character of windfall gains that affect economic outcomes both directly and indirectly. Several studies have shown that the indirect effect typically works via institutions like corruption. In this article, we offer a theoretical framework for a joi...... in a large cross-section of countries. Our results suggest that whereas more aid means less corruption, natural resource rents is positively correlated with corruption, although both relationships are non-linear......Natural resource rents and foreign aid have the character of windfall gains that affect economic outcomes both directly and indirectly. Several studies have shown that the indirect effect typically works via institutions like corruption. In this article, we offer a theoretical framework for a joint...

  4. Feedback Loop Gains and Feedback Behavior (1996)

    DEFF Research Database (Denmark)

    Kampmann, Christian Erik

    2012-01-01

    Linking feedback loops and system behavior is part of the foundation of system dynamics, yet the lack of formal tools has so far prevented a systematic application of the concept, except for very simple systems. Having such tools at their disposal would be a great help to analysts in understanding...... large, complicated simulation models. The paper applies tools from graph theory formally linking individual feedback loop strengths to the system eigenvalues. The significance of a link or a loop gain and an eigenvalue can be expressed in the eigenvalue elasticity, i.e., the relative change...... of an eigenvalue resulting from a relative change in the gain. The elasticities of individual links and loops may be found through simple matrix operations on the linearized system. Even though the number of feedback loops can grow rapidly with system size, reaching astronomical proportions even for modest systems...

  5. Spontaneous indices are inconsistent with arterial baroreflex gain.

    Science.gov (United States)

    Lipman, Ruth D; Salisbury, Julie K; Taylor, J Andrew

    2003-10-01

    Spontaneously occurring, parallel fluctuations in arterial pressure and heart period are frequently used as indices of baroreflex function. Despite the convenience of spontaneous indices, their relation to the arterial baroreflex remains unclear. Therefore, in 97 volunteers, we derived 5 proposed indices (sequence method, alpha-index, transfer function, low-frequency transfer function, and impulse response function), compared them with arterial baroreflex gain (by the modified Oxford pharmacologic technique), and examined their relation to carotid distensibility and respiratory sinus arrhythmia. The subjects comprised men and women (n=41) aged 25 to 86 years, 30% of whom had established coronary artery disease. Generally, the indices were correlated with each other (except alpha-index and low-frequency transfer function) and with baroreflex gain. However, the Bland-Altman method demonstrated that the spontaneous indices had limits of agreement as large as the baroreflex gain itself. Even in individuals within the lowest tertile of baroreflex gain for whom baroreflex gain appears to be the most clinically relevant, spontaneous indices failed to relate to baroreflex gain. In fact, for these individuals, there was no correlation between any index and baroreflex gain. Forward stepwise linear regression showed that all spontaneous indices and baroreflex gain were related to respiratory sinus arrhythmia, but only baroreflex gain was related to carotid distensibility. Therefore, these data suggest that spontaneous indices are inadequate estimates of gain and are inconsistent with arterial baroreflex function.

  6. A therapeutic gain model for brachytherapy

    International Nuclear Information System (INIS)

    Wigg, D.R.

    2003-01-01

    When treating with continuous irradiation the potential therapeutic gain or loss depends on several treatment, normal tissue and tumour variables. There are similarities between equations defining tissue effects with fractionated treatment and brachytherapy. The former is sensitive to dose per fraction (and incomplete repair for short intervals between treatments) and the later is sensitive to dose rate and continuous repair factors. Because of these similarities, for typical tumours and normal tissues, dose per fraction and dose rates generally work in similar directions. As the dose per fraction or dose rate increases the therapeutic gain falls. With continuous irradiation the dose rates effects are determined by Beta cell kill and hence the absolute value of Beta . Minimal sensitivity occurs at very low and very high dose rates. The magnitude of cell kill also depends on the Continuous Repair Factor (g) which is a function of the treatment time and the Repair Half Time (in hours) of the tissues (Repair Half Time T 1/2Ln(2)/h, when h the Repair Constant). An interactive optimising model has been written to predict the therapeutic gain or loss as the parameter values are varied. This model includes the tumour and normal tissue parameters alpha and beta Gy (or individual values), their Repair Half Times, dose rates and overall treatment time. The model is based on the Linear-Quadratic equation and the Total Effect (TE) method of Thames and Hendry although the Extrapolated Response Dose (ERD) method of Barendsen produces the same results. The model is written so that the gain or loss may be seen when treatment is always to normal tissue tolerance doses. The magnitude of the therapeutic loss as the dose rate increases and its sensitivity to changes in normal tissue and tumour parameter values is clearly demonstrated

  7. Eyewitness identification: Bayesian information gain, base-rate effect equivalency curves, and reasonable suspicion.

    Science.gov (United States)

    Wells, Gary L; Yang, Yueran; Smalarz, Laura

    2015-04-01

    We provide a novel Bayesian treatment of the eyewitness identification problem as it relates to various system variables, such as instruction effects, lineup presentation format, lineup-filler similarity, lineup administrator influence, and show-ups versus lineups. We describe why eyewitness identification is a natural Bayesian problem and how numerous important observations require careful consideration of base rates. Moreover, we argue that the base rate in eyewitness identification should be construed as a system variable (under the control of the justice system). We then use prior-by-posterior curves and information-gain curves to examine data obtained from a large number of published experiments. Next, we show how information-gain curves are moderated by system variables and by witness confidence and we note how information-gain curves reveal that lineups are consistently more proficient at incriminating the guilty than they are at exonerating the innocent. We then introduce a new type of analysis that we developed called base rate effect-equivalency (BREE) curves. BREE curves display how much change in the base rate is required to match the impact of any given system variable. The results indicate that even relatively modest changes to the base rate can have more impact on the reliability of eyewitness identification evidence than do the traditional system variables that have received so much attention in the literature. We note how this Bayesian analysis of eyewitness identification has implications for the question of whether there ought to be a reasonable-suspicion criterion for placing a person into the jeopardy of an identification procedure. (c) 2015 APA, all rights reserved).

  8. Robust control for spacecraft rendezvous system with actuator unsymmetrical saturation: a gain scheduling approach

    Science.gov (United States)

    Wang, Qian; Xue, Anke

    2018-06-01

    This paper has proposed a robust control for the spacecraft rendezvous system by considering the parameter uncertainties and actuator unsymmetrical saturation based on the discrete gain scheduling approach. By changing of variables, we transform the actuator unsymmetrical saturation control problem into a symmetrical one. The main advantage of the proposed method is improving the dynamic performance of the closed-loop system with a region of attraction as large as possible. By the Lyapunov approach and the scheduling technology, the existence conditions for the admissible controller are formulated in the form of linear matrix inequalities. The numerical simulation illustrates the effectiveness of the proposed method.

  9. A Novel Real-Time Path Servo Control of a Hardware-in-the-Loop for a Large-Stroke Asymmetric Rod-Less Pneumatic System under Variable Loads

    Directory of Open Access Journals (Sweden)

    Hao-Ting Lin

    2017-06-01

    Full Text Available This project aims to develop a novel large stroke asymmetric pneumatic servo system of a hardware-in-the-loop for path tracking control under variable loads based on the MATLAB Simulink real-time system. High pressure compressed air provided by the air compressor is utilized for the pneumatic proportional servo valve to drive the large stroke asymmetric rod-less pneumatic actuator. Due to the pressure differences between two chambers, the pneumatic actuator will operate. The highly nonlinear mathematical models of the large stroke asymmetric pneumatic system were analyzed and developed. The functional approximation technique based on the sliding mode controller (FASC is developed as a controller to solve the uncertain time-varying nonlinear system. The MATLAB Simulink real-time system was a main control unit of a hardware-in-the-loop system proposed to establish driver blocks for analog and digital I/O, a linear encoder, a CPU and a large stroke asymmetric pneumatic rod-less system. By the position sensor, the position signals of the cylinder will be measured immediately. The measured signals will be viewed as the feedback signals of the pneumatic servo system for the study of real-time positioning control and path tracking control. Finally, real-time control of a large stroke asymmetric pneumatic servo system with measuring system, a large stroke asymmetric pneumatic servo system, data acquisition system and the control strategy software will be implemented. Thus, upgrading the high position precision and the trajectory tracking performance of the large stroke asymmetric pneumatic servo system will be realized to promote the high position precision and path tracking capability. Experimental results show that fifth order paths in various strokes and the sine wave path are successfully implemented in the test rig. Also, results of variable loads under the different angle were implemented experimentally.

  10. A Novel Real-Time Path Servo Control of a Hardware-in-the-Loop for a Large-Stroke Asymmetric Rod-Less Pneumatic System under Variable Loads.

    Science.gov (United States)

    Lin, Hao-Ting

    2017-06-04

    This project aims to develop a novel large stroke asymmetric pneumatic servo system of a hardware-in-the-loop for path tracking control under variable loads based on the MATLAB Simulink real-time system. High pressure compressed air provided by the air compressor is utilized for the pneumatic proportional servo valve to drive the large stroke asymmetric rod-less pneumatic actuator. Due to the pressure differences between two chambers, the pneumatic actuator will operate. The highly nonlinear mathematical models of the large stroke asymmetric pneumatic system were analyzed and developed. The functional approximation technique based on the sliding mode controller (FASC) is developed as a controller to solve the uncertain time-varying nonlinear system. The MATLAB Simulink real-time system was a main control unit of a hardware-in-the-loop system proposed to establish driver blocks for analog and digital I/O, a linear encoder, a CPU and a large stroke asymmetric pneumatic rod-less system. By the position sensor, the position signals of the cylinder will be measured immediately. The measured signals will be viewed as the feedback signals of the pneumatic servo system for the study of real-time positioning control and path tracking control. Finally, real-time control of a large stroke asymmetric pneumatic servo system with measuring system, a large stroke asymmetric pneumatic servo system, data acquisition system and the control strategy software will be implemented. Thus, upgrading the high position precision and the trajectory tracking performance of the large stroke asymmetric pneumatic servo system will be realized to promote the high position precision and path tracking capability. Experimental results show that fifth order paths in various strokes and the sine wave path are successfully implemented in the test rig. Also, results of variable loads under the different angle were implemented experimentally.

  11. A numerical algorithm for optimal feedback gains in high dimensional linear quadratic regulator problems

    Science.gov (United States)

    Banks, H. T.; Ito, K.

    1991-01-01

    A hybrid method for computing the feedback gains in linear quadratic regulator problem is proposed. The method, which combines use of a Chandrasekhar type system with an iteration of the Newton-Kleinman form with variable acceleration parameter Smith schemes, is formulated to efficiently compute directly the feedback gains rather than solutions of an associated Riccati equation. The hybrid method is particularly appropriate when used with large dimensional systems such as those arising in approximating infinite-dimensional (distributed parameter) control systems (e.g., those governed by delay-differential and partial differential equations). Computational advantages of the proposed algorithm over the standard eigenvector (Potter, Laub-Schur) based techniques are discussed, and numerical evidence of the efficacy of these ideas is presented.

  12. Large Diversity of Porcine Yersinia enterocolitica 4/O:3 in Eight European Countries Assessed by Multiple-Locus Variable-Number Tandem-Repeat Analysis.

    Science.gov (United States)

    Alakurtti, Sini; Keto-Timonen, Riikka; Virtanen, Sonja; Martínez, Pilar Ortiz; Laukkanen-Ninios, Riikka; Korkeala, Hannu

    2016-06-01

    A total of 253 multiple-locus variable-number tandem-repeat analysis (MLVA) types among 634 isolates were discovered while studying the genetic diversity of porcine Yersinia enterocolitica 4/O:3 isolates from eight different European countries. Six variable-number tandem-repeat (VNTR) loci V2A, V4, V5, V6, V7, and V9 were used to study the isolates from 82 farms in Belgium (n = 93, 7 farms), England (n = 41, 8 farms), Estonia (n = 106, 12 farms), Finland (n = 70, 13 farms), Italy (n = 111, 20 farms), Latvia (n = 66, 3 farms), Russia (n = 60, 10 farms), and Spain (n = 87, 9 farms). Cluster analysis revealed mainly country-specific clusters, and only one MLVA type consisting of two isolates was found from two countries: Russia and Italy. Also, farm-specific clusters were discovered, but same MLVA types could also be found from different farms. Analysis of multiple isolates originating either from the same tonsils (n = 4) or from the same farm, but 6 months apart, revealed both identical and different MLVA types. MLVA showed a very good discriminatory ability with a Simpson's discriminatory index (DI) of 0.989. DIs for VNTR loci V2A, V4, V5, V6, V7, and V9 were 0.916, 0.791, 0.901, 0.877, 0.912, and 0.785, respectively, when studying all isolates together, but variation was evident between isolates originating from different countries. Locus V4 in the Spanish isolates and locus V9 in the Latvian isolates did not differentiate (DI 0.000), and locus V9 in the English isolates showed very low discriminatory power (DI 0.049). The porcine Y. enterocolitica 4/O:3 isolates were diverse, but the variation in DI demonstrates that the well discriminating loci V2A, V5, V6, and V7 should be included in MLVA protocol when maximal discriminatory power is needed.

  13. Developmental Gains in Visuospatial Memory Predict Gains in Mathematics Achievement

    OpenAIRE

    Li, Yaoran; Geary, David C.

    2013-01-01

    Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusiv...

  14. Denver Developmental Test Findings and their Relationship with Sociodemographic Variables in a Large Community Sample of 0-4-Year-Old Children.

    Science.gov (United States)

    Çelikkiran, Seyhan; Bozkurt, Hasan; Coşkun, Murat

    2015-06-01

    The aim of this study was to investigate the prevalence of developmental problems and relationship with sociodemographic variables in a community sample of young children. Participants included 1000 children (558 males, 442 females, age range 1-48 months, mean 18.4 months, SD 7.8 months). Children were referred generally by their parents for developmental evaluation and consultation in response to a public announcement in a district area in Istanbul, Turkey. An interview form and the Denver Developmental Screening Test II (DDST) were used for sociodemographic data and developmental evaluation. The χ 2 test and Pearson's correlation test were used for data analysis. Seven hundred forty-one out of 1000 children (74.1%) had normal, 140 (14%) had risky, and 119 (11.9%) had abnormal findings on the DDST results. The probability of abnormal findings on the DDST results was significantly higher in males (p=0.003), the 2-4-year-old group (pone child (p=0.001), consanguineous marriages (p0.05). Sociodemographic factors have a noteworthy impact on development. Determining these factors is important especially during the first years of life.

  15. Aging Reservoirs in a Changing Climate: Examining Storage Loss of Large Reservoirs and Variability of Sedimentation Rate in a Dominant Cropland Region

    Science.gov (United States)

    Rahmani, V.; Kastens, J.; deNoyelles, F.; Huggins, D.; Martinko, E.

    2015-12-01

    Dam construction has multiple environmental and hydrological consequences including impacts on upstream and downstream ecosystems, water chemistry, and streamflow. Behind the dam the reservoir can trap sediment from the stream and fill over time. With increasing population and drinking and irrigation water demands, particularly in the areas that have highly variable weather and extended drought periods such as the United States Great Plains, reservoir sedimentation escalates water management concerns. Under nearly all projected climate change scenarios we expect that reservoir water storage and management will come under intense scrutiny because of the extensive use of interstate river compacts in the Great Plains. In the state of Kansas, located in the Great Plains, bathymetric surveys have been completed during the last decade for many major lakes by the Kansas Biological Survey, Kansas Water Office, and the U.S. Army Corps of Engineers. In this paper, we studied the spatial and temporal changes of reservoir characteristics including sedimentation yield, depletion rate, and storage capacity loss for 24 federally-operated reservoirs in Kansas. These reservoirs have an average age of about 50 years and collectively have lost approximately 15% of their original capacity, with the highest annual observed single-reservoir depletion rate of 0.84% and sedimentation yield of 1,685 m3 km-2 yr-1.

  16. Fabrication and evaluation of variable focus and large deformation plano-convex microlens based on non-ionic poly(vinyl chloride)/dibutyl adipate gels

    International Nuclear Information System (INIS)

    Kim, Sang-Youn; Yeo, Myoung; Shin, Eun-Jae; Park, Won-Hyeong; Jang, Jong-Seok; Nam, Byeong-Uk; Bae, Jin Woo

    2015-01-01

    In this paper, we propose a variable focus microlens module based on a transparent, electroactive, and non-ionic PVC/DBA gel. A non-ionic PVC/DBA (nPVC) gel on an ITO glass was confined beneath a rigid annular electrode, and applied pressure squeezed a bulge of the nPVC gel into the annular electrode, resulting in a hemispherical plano-convex nPVC gel microlens. The proposed nPVC gel microlens was analyzed and optimized. When voltage is applied to the circular perimeter (the annular electrode) of this fabricated microlens, electrically induced creep deformation of the nPVC gel occurs, changing its optical focal length. The focal length remarkably increases from 3.8 mm up to 14.3 mm with increasing applied voltages from 300 V to 800 V. Due to its compact, transparent, and electroactive characteristics, the proposed nPVC gel microlens can be easily inserted into small consumer electronic devices, such as digital cameras, camcorders, cell phones, and other portable optical devices. (paper)

  17. Theoretical and numerical study of free shear flows with large density ratio; Etude theorique et numerique des ecoulements cisailles libres a masse volumique fortement variable

    Energy Technology Data Exchange (ETDEWEB)

    Lardjane, N.

    2002-05-15

    The subject of this work concerns the application of large-eddy simulation to the mixing of two fluids with different thermodynamical properties. Numerical errors in the discretization of Navier-Stokes equations and their interaction with sub-grid models are investigated on a self decaying isotropic homogeneous turbulence. A high resolution numerical code is then developed for the simulation of binary mixing layers. Reduction of early acoustic waves amplitude is achieved by use of a temporal self-similar initial condition. The relative magnitude of sub-grid terms arising from filtered equations is investigated on explicit filtering of direct numerical simulation results of temporal N{sub 2}/O{sub 2} and H{sub 2}/O{sub 2} mixing layers. Implicit closure (MILES) is then evoked on the basis of WENO schemes. (author)

  18. Joubert syndrome: large clinical variability and a unique neuroimaging aspect Síndrome de Joubert: grande variabilidade clínica e uma neuroimagem característica

    Directory of Open Access Journals (Sweden)

    Emília Katiane Embiruçu Leão

    2010-04-01

    Full Text Available Joubert syndrome (JS is an autosomal recessive inherited disorder characterized by hypotonia, cerebellar vermis hypoplasia, ocular abnormalities (e.g, pigmentary retinopathy, oculomotor apraxia and nystagmus, renal cysts and hepatic fibrosis. Respiratory abnormalities, as apnea and hyperpnea, may be present, as well as mental retardation. At least seven JS loci have been determined and five genes identified. Herein, we report five children, belonging to independent families, with JS: they shared the same typical MRI abnormality, known as molar tooth sign, but had an otherwise quite variable phenotype, regarding mostly their cognitive performance, visual abilities and extra-neurological compromise.A síndrome de Joubert (SJ é uma doença hereditária, autossômica recessiva, caracterizada por hipotonia, hipoplasia do vermis cerebelar, anormalidades oculares (p.ex., retinite pigmentar, apraxia oculomotora e nistagmo, cistos renais e fibrose hepática. Anormalidades respiratórias tais como apnéia e hiperpnéia podem estar presentes, assim como deficiência mental. Pelo menos sete loci e cinco genes diferentes associados à SJ já foram identificados. Este artigo relata cinco crianças com SJ, pertencentes a diferentes famílias. Todos os pacientes compartilham a mesma anormalidade típica da RM, conhecida como sinal do dente molar, e apresentam ampla variabilidade clínica em relação ao desempenho cognitivo, comprometimento visual e alterações extra-neurológicas.

  19. Interventions to reduce weight gain in schizophrenia.

    Science.gov (United States)

    Faulkner, G; Cohn, T; Remington, G

    2007-01-24

    , short study duration and by variability of the interventions themselves, their intensity and duration. Future studies adequately powered, with longer treatment duration and rigorous methodology will be needed in further evaluating the efficacy and safety of weight loss interventions for moderating weight gain. At this stage, there is insufficient evidence to support the general use of pharmacological interventions for weight management in people with schizophrenia.

  20. Interventions to reduce weight gain in schizophrenia

    Science.gov (United States)

    Faulkner, Guy; Cohn, Tony; Remington, Gary

    2014-01-01

    pharmacological and non pharmacological interventions. However, interpretation is limited by the small number of studies, small sample size, short study duration and by variability of the interventions themselves, their intensity and duration. Future studies adequately powered, with longer treatment duration and rigorous methodology will be needed in further evaluating the efficacy and safety of weight loss interventions for moderating weight gain. At this stage, there is insufficient evidence to support the general use of pharmacological interventions for weight management in people with schizophrenia. PMID:17253540

  1. Large variability in synaptic N-methyl-D-aspartate receptor density on interneurons and a comparison with pyramidal-cell spines in the rat hippocampus.

    Science.gov (United States)

    Nyíri, G; Stephenson, F A; Freund, T F; Somogyi, P

    2003-01-01

    Pyramidal cells receive input from several types of GABA-releasing interneurons and innervate them reciprocally. Glutamatergic activation of interneurons involves both alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) type glutamate receptors expressed in type I synapses, mostly on their dendritic shafts. On average, the synaptic AMPA receptor content is several times higher on interneurons than in the spines of pyramidal cells. To compare the NMDA receptor content of synapses, we used a quantitative postembedding immunogold technique on serial electron microscopic sections, and analysed the synapses on interneuron dendrites and pyramidal cell spines in the CA1 area. Because all NMDA receptors contain the obligatory NR1 subunit, receptor localisation was carried out using antibodies recognising all splice variants of the NR1 subunit. Four populations of synapse were examined: i). on spines of pyramidal cells in stratum (str.) radiatum and str. oriens; ii). on parvalbumin-positive interneuronal dendritic shafts in str. radiatum; iii). on randomly found dendritic shafts in str. oriens and iv). on somatostatin-positive interneuronal dendritic shafts and somata in str. oriens. On average, the size of the synapses on spines was about half of those on interneurons. The four populations of synapse significantly differed in labelling for the NR1 subunit. The median density of NR1 subunit labelling was highest on pyramidal cell spines. It was lowest in the synapses on parvalbumin-positive dendrites in str. radiatum, where more than half of these synapses were immunonegative. In str. oriens, synapses on interneurons had a high variability of receptor content; some dendrites were similar to those in str. radiatum, including the proximal synapses of somatostatin-positive cells, whereas others had immunoreactivity for the NR1 subunit similar to or higher than synapses on pyramidal cell spines. These results show that synaptic NMDA

  2. Implications of Spatial Variability in Heat Flow for Geothermal Resource Evaluation in Large Foreland Basins: The Case of the Western Canada Sedimentary Basin

    Directory of Open Access Journals (Sweden)

    Simon Weides

    2014-04-01

    Full Text Available Heat flow and geothermal gradient of the sedimentary succession of the Western Canada Sedimentary Basin (WCSB are mapped based on a large thermal database. Heat flow in the deep part of the basin varies from 30 mW/m2 in the south to high 100 mW/m2 in the north. As permeable strata are required for a successful geothermal application, the most important aquifers are discussed and evaluated. Regional temperature distribution within different aquifers is mapped for the first time, enabling a delineation of the most promising areas based on thermal field and aquifer properties. Results of previous regional studies on the geothermal potential of the WCSB are newly evaluated and discussed. In parts of the WCSB temperatures as high as 100–210 °C exist at depths of 3–5 km. Fluids from deep aquifers in these “hot” regions of the WCSB could be used in geothermal power plants to produce electricity. The geothermal resources of the shallower parts of the WCSB (>2 km could be used for warm water provision (>50 °C or district heating (>70 °C in urban areas.

  3. Optomechanical transistor with mechanical gain

    Science.gov (United States)

    Zhang, X. Z.; Tian, Lin; Li, Yong

    2018-04-01

    We study an optomechanical transistor, where an input field can be transferred and amplified unidirectionally in a cyclic three-mode optomechanical system. In this system, the mechanical resonator is coupled simultaneously to two cavity modes. We show that it only requires a finite mechanical gain to achieve the nonreciprocal amplification. Here the nonreciprocity is caused by the phase difference between the linearized optomechanical couplings that breaks the time-reversal symmetry of this system. The amplification arises from the mechanical gain, which provides an effective phonon bath that pumps the mechanical mode coherently. This effect is analogous to the stimulated emission of atoms, where the probe field can be amplified when its frequency is in resonance with that of the anti-Stokes transition. We show that by choosing optimal parameters, this optomechanical transistor can reach perfect unidirectionality accompanied with strong amplification. In addition, the presence of the mechanical gain can result in ultralong delay in the phase of the probe field, which provides an alternative to controlling light transport in optomechanical systems.

  4. Pressure Gain Combustion for Gas Turbines

    Science.gov (United States)

    2013-08-20

    downstream of a large  diesel  engine, they tested three turbine geometries the best experienced  a drop in efficiency of 10%.   A few people have  looked...Society of Mechanical Engineers Turbo Expo 1995 [3] Heffer, J., 2010, Integration of Pressure Gain Combustion with Gas Turbines, Ph.D. Thesis...investigated  an  axial  turbocharger  designed  for  use  downstream  of  a  large  diesel   engine,  they  tested  three  turbine geometries the best

  5. Geographic origin is not supported by the genetic variability found in a large living collection of Jatropha curcas with accessions from three continents.

    Science.gov (United States)

    Maghuly, Fatemeh; Jankowicz-Cieslak, Joanna; Pabinger, Stephan; Till, Bradley J; Laimer, Margit

    2015-04-01

    Increasing economic interest in Jatropha curcas requires a major research focus on the genetic background and geographic origin of this non-edible biofuel crop. To determine the worldwide genetic structure of this species, amplified fragment length polymorphisms, inter simple sequence repeats, and novel single nucleotide polymorphisms (SNPs) were employed for a large collection of 907 J. curcas accessions and related species (RS) from three continents, 15 countries and 53 regions. PCoA, phenogram, and cophenetic analyses separated RS from two J. curcas groups. Accessions from Mexico, Bolivia, Paraguay, Kenya, and Ethiopia with unknown origins were found in both groups. In general, there was a considerable overlap between individuals from different regions and countries. The Bayesian approach using STRUCTURE demonstrated two groups with a low genetic variation. Analysis of molecular varience revealed significant variation among individuals within populations. SNPs found by in silico analyses of Δ12 fatty acid desaturase indicated possible changes in gene expression and thus in fatty acid profiles. SNP variation was higher in the curcin gene compared to genes involved in oil production. Novel SNPs allowed separating toxic, non-toxic, and Mexican accessions. The present study confirms that human activities had a major influence on the genetic diversity of J. curcas, not only because of domestication, but also because of biased selection. © 2015 The Authors. Biotechnology Journal published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

  6. Genomic Variability of Mycobacterium tuberculosis Strains of the Euro-American Lineage Based on Large Sequence Deletions and 15-Locus MIRU-VNTR Polymorphism

    Science.gov (United States)

    Rindi, Laura; Medici, Chiara; Bimbi, Nicola; Buzzigoli, Andrea; Lari, Nicoletta; Garzelli, Carlo

    2014-01-01

    A sample of 260 Mycobacterium tuberculosis strains assigned to the Euro-American family was studied to identify phylogenetically informative genomic regions of difference (RD). Mutually exclusive deletions of regions RD115, RD122, RD174, RD182, RD183, RD193, RD219, RD726 and RD761 were found in 202 strains; the RDRio deletion was detected exclusively among the RD174-deleted strains. Although certain deletions were found more frequently in certain spoligotype families (i.e., deletion RD115 in T and LAM, RD174 in LAM, RD182 in Haarlem, RD219 in T and RD726 in the “Cameroon” family), the RD-defined sublineages did not specifically match with spoligotype-defined families, thus arguing against the use of spoligotyping for establishing exact phylogenetic relationships between strains. Notably, when tested for katG463/gyrA95 polymorphism, all the RD-defined sublineages belonged to Principal Genotypic Group (PGG) 2, except sublineage RD219 exclusively belonging to PGG3; the 58 Euro-American strains with no deletion were of either PGG2 or 3. A representative sample of 197 isolates was then analyzed by standard 15-locus MIRU-VNTR typing, a suitable approach to independently assess genetic relationships among the strains. Analysis of the MIRU-VNTR typing results by using a minimum spanning tree (MST) and a classical dendrogram showed groupings that were largely concordant with those obtained by RD-based analysis. Isolates of a given RD profile show, in addition to closely related MIRU-VNTR profiles, related spoligotype profiles that can serve as a basis for better spoligotype-based classification. PMID:25197794

  7. SiPM Gain Stabilization Studies for Adaptive Power Supply

    CERN Document Server

    AUTHOR|(CDS)2074257; Zalieckas, Justas; Cvach, Jaroslav; Kvasnicka, Jiri; Polak, Ivo

    2016-01-01

    We present herein gain stabilization studies of SiPMs using a climate chamber at CERN. We present results for four detectors not tested before, three from Hamamatsu and one from KETEK. Two of the Hamamatsu SiPMs are novel sensors with trenches that reduce cross talk. We use an improved readout system with a digital oscilloscope controlled with a dedicated LabView program. We improved and automized the analysis to deal with large datasets. We have measured the gain-versus-bias-voltage dependence at fixed temperature and gain-versus-temperature dependence at fixed bias voltage to determine the bias voltage dependence on temperature $V(T)$ for stable gain. We show that the gain remains stable to better than $\\pm 0.5\\%$ in the $20^\\circ \\rm C - 30^\\circ C$ temperature range if the bias voltage is properly adjusted with temperature.

  8. Predicting Intelligibility Gains in Dysarthria through Automated Speech Feature Analysis

    Science.gov (United States)

    Fletcher, Annalise R.; Wisler, Alan A.; McAuliffe, Megan J.; Lansford, Kaitlin L.; Liss, Julie M.

    2017-01-01

    Purpose: Behavioral speech modifications have variable effects on the intelligibility of speakers with dysarthria. In the companion article, a significant relationship was found between measures of speakers' baseline speech and their intelligibility gains following cues to speak louder and reduce rate (Fletcher, McAuliffe, Lansford, Sinex, &…

  9. Temporal Gain Correction for X-Ray Calorimeter Spectrometers

    Science.gov (United States)

    Porter, F. S.; Chiao, M. P.; Eckart, M. E.; Fujimoto, R.; Ishisaki, Y.; Kelley, R. L.; Kilbourne, C. A.; Leutenegger, M. A.; McCammon, D.; Mitsuda, K.

    2016-01-01

    Calorimetric X-ray detectors are very sensitive to their environment. The boundary conditions can have a profound effect on the gain including heat sink temperature, the local radiation temperature, bias, and the temperature of the readout electronics. Any variation in the boundary conditions can cause temporal variations in the gain of the detector and compromise both the energy scale and the resolving power of the spectrometer. Most production X-ray calorimeter spectrometers, both on the ground and in space, have some means of tracking the gain as a function of time, often using a calibration spectral line. For small gain changes, a linear stretch correction is often sufficient. However, the detectors are intrinsically non-linear and often the event analysis, i.e., shaping, optimal filters etc., add additional non-linearity. Thus for large gain variations or when the best possible precision is required, a linear stretch correction is not sufficient. Here, we discuss a new correction technique based on non-linear interpolation of the energy-scale functions. Using Astro-HSXS calibration data, we demonstrate that the correction can recover the X-ray energy to better than 1 part in 104 over the entire spectral band to above 12 keV even for large-scale gain variations. This method will be used to correct any temporal drift of the on-orbit per-pixel gain using on-board calibration sources for the SXS instrument on the Astro-H observatory.

  10. Commutated automatic gain control system

    Science.gov (United States)

    Yost, S. R.

    1982-01-01

    A commutated automatic gain control (AGC) system was designed and built for a prototype Loran C receiver. The receiver uses a microcomputer to control a memory aided phase-locked loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The circuit designed for the AGC is described, and bench and flight test results are presented. The AGC circuit described actually samples starting at a point 40 microseconds after a zero crossing determined by the software lock pulse ultimately generated by a 30 microsecond delay and add network in the receiver front end envelope detector.

  11. [Fast food promotes weight gain].

    Science.gov (United States)

    Stender, Steen; Dyerberg, Jørn; Astrup, Arne V

    2007-05-07

    The total amounts of fat in a fast food menu consisting of French fries and fried Chicken Nuggets from McDonald's and KFC, respectively, bought in 35 different countries vary from 41 to 71 gram. In most countries the menu contained unacceptably high amounts of industrially-produced trans fat which contributes to an increased risk of ischaemic heart disease, weight gain, abdominal fat accumulation and type 2 diabetes. The quality of the ingredients in fast food ought to be better and the size of the portions smaller and less energy-dense so that frequent fast food meals do not increase the risk of obesity and diseases among customers.

  12. Effects of having a baby on weight gain.

    Science.gov (United States)

    Brown, Wendy J; Hockey, Richard; Dobson, Annette J

    2010-02-01

    Women often blame weight gain in early adulthood on having a baby. The aim was to estimate the weight gain attributable to having a baby, after disentangling the effects of other factors that influence weight change at this life stage. A longitudinal study of a randomly selected cohort of 6458 Australian women, aged 18-23 years in 1996, was conducted. Self-report mailed surveys were completed in 1996, 2000, 2003, and 2006, and data were analyzed in 2008. On average, women gained weight at the rate of 0.93% per year (95% CI=0.89, 0.98) or 605 g/year (95% CI=580, 635) for a 65-kg woman. Over the 10-year study period, partnered women with one baby gained almost 4 kg more, and those with a partner but no baby gained 1.8 kg more, than unpartnered childless women (after adjustment for other significant factors: initial BMI and age; physical activity, sitting time, energy intake (2003); education level, hours in paid work, and smoking). Having a baby has a marked effect on 10-year weight gain, but there is also an effect attributable to getting married or living with a partner. Social and lifestyle as well as energy balance variables should be considered when developing strategies to prevent weight gain in young adult women. Copyright 2010 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  13. Can Beta Blockers Cause Weight Gain?

    Science.gov (United States)

    ... cause weight gain? Can beta blockers cause weight gain? Answers from Sheldon G. Sheps, M.D. Yes. Weight gain can occur as a side effect of some ... and metoprolol (Lopressor, Toprol-XL). The average weight gain is about 2.6 pounds (about 1.2 ...

  14. A gain-coefficient switched Alexandrite laser

    International Nuclear Information System (INIS)

    Lee, Chris J; Van der Slot, Peter J M; Boller, Klaus-J

    2013-01-01

    We report on a gain-coefficient switched Alexandrite laser. An electro-optic modulator is used to switch between high and low gain states by making use of the polarization dependent gain of Alexandrite. In gain-coefficient switched mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a repetition rate of 5 Hz.

  15. Estimating the potential gains from mergers

    DEFF Research Database (Denmark)

    Bogetoft, Peter; Wang, Dexiang

    2005-01-01

    We introduce simple production economic models to estimate the potential gains from mergers. We decompose the gains into technical ef¿ciency, size (scale) and harmony (mix) gains, and we discuss alternative ways to capture these gains. We propose to approximate the production processes using...... the non-parametric. Data Envelopment Analysis (DEA) approach, and we use the resulting operational approach to estimate the potential gains from merging agricultural extension of¿ces in Denmark....

  16. Association of maternal risk factors with large for gestational age fetuses in Indian population

    OpenAIRE

    Shamim Khandaker; Shabana Munshi

    2015-01-01

    Objective: To estimate the risk of delivering large-for gestational age (LGA) fetuses associated with maternal obesity, excessive maternal weight gain, and gestational diabetes mellitus (GDM)- in Indian mothers. Design: Retrospective study. Settings: Fernandez Hospital Private Limited, Hyderabad, Andhra Pradesh, India; a tertiary perinatal centre. Populations: Pregnant singleton mothers with correct pregnancy dating. Methods: Estimated fetal weight (EFW) is determined using ultrasound variabl...

  17. Heritability of gestational weight gain

    DEFF Research Database (Denmark)

    Andersson, Elina Scheers; Silventoinen, Karri; Tynelius, Per

    2015-01-01

    Gestational weight gain (GWG) is a complex trait involving intrauterine environmental, maternal environmental, and genetic factors. However, the extent to which these factors contribute to the total variation in GWG is unclear. We therefore examined the genetic and environmental influences...... on the variation in GWG in the first and second pregnancy in monozygotic (MZ) and dizygotic (DZ) twin mother-pairs. Further, we explored if any co-variance existed between factors influencing the variation in GWG of the mothers’ first and second pregnancies. By using Swedish nationwide record-linkage data, we...... identified 694 twin mother-pairs with complete data on their first pregnancy and 465 twin mother-pairs with complete data on their second pregnancy during 1982–2010. For a subanalysis, 143 twin mother-pairs had complete data on two consecutive pregnancies during the study period. We used structural equation...

  18. Unidirectional high gain brake stop

    Science.gov (United States)

    Lang, David J. (Inventor)

    1987-01-01

    This invention relates to a unidirectional high gain brake arrangement that includes in combination a shaft mounted for rotation within a housing. The shaft is rotatable in either direction. A brake is selectively releasably coupled to the housing and to the shaft. The brake has a first member. An intermittent motion device is respectively coupled through the first member to the housing and through a one-way clutch to the shaft. The brake also has a second member that is mechanically coupled to the first brake member and to the housing. The intermittent motion device causes the brake to be activated by movement imparted to the first brake member after a preset number of revolutions of the shaft in one direction. The brake is released by rotation of the shaft in an opposite direction whereby torque transmitted through the one-way clutch to the first brake member is removed.

  19. Boesmanland gains from nuclear wastes

    International Nuclear Information System (INIS)

    Smit, I.

    1984-01-01

    It is being claimed that the geobotany of the Boesmanland will gain from the use of the farm Vaalputs for radioactive waste disposal from the Koeberg nuclear power station. Only 1 km 2 of the 10 000 ha that was bought for the purpose will be used for the disposal of low-level radioactive wastes and 2 m 3 to 3 m 3 per year will be used for the storage of high-level radioactive wastes. The rest of the area, Nucor plans to develop as a nature reserve, restoring the natural botany and ecology. Before Vaalputs was selected as site for radioactive waste disposal, a regional analysis was done. According to this there is more or less 500 people staying within a radius of 25km from the farm. Geological surveys showed no mineral deposits of economic value. During the past 100 million years the area was also free from seismic activity

  20. Variability in warm-season atmospheric circulation and precipitation patterns over subtropical South America: relationships between the South Atlantic convergence zone and large-scale organized convection over the La Plata basin

    Science.gov (United States)

    Mattingly, Kyle S.; Mote, Thomas L.

    2017-01-01

    Warm-season precipitation variability over subtropical South America is characterized by an inverse relationship between the South Atlantic convergence zone (SACZ) and precipitation over the central and western La Plata basin of southeastern South America. This study extends the analysis of this "South American Seesaw" precipitation dipole to relationships between the SACZ and large, long-lived mesoscale convective systems (LLCSs) over the La Plata basin. By classifying SACZ events into distinct continental and oceanic categories and building a logistic regression model that relates LLCS activity across the region to continental and oceanic SACZ precipitation, a detailed account of spatial variability in the out-of-phase coupling between the SACZ and large-scale organized convection over the La Plata basin is provided. Enhanced precipitation in the continental SACZ is found to result in increased LLCS activity over northern, northeastern, and western sections of the La Plata basin, in association with poleward atmospheric moisture flux from the Amazon basin toward these regions, and a decrease in the probability of LLCS occurrence over the southeastern La Plata basin. Increased oceanic SACZ precipitation, however, was strongly related to reduced atmospheric moisture and decreased probability of LLCS occurrence over nearly the entire La Plata basin. These results suggest that continental SACZ activity and large-scale organized convection over the northern and eastern sections of the La Plata basin are closely tied to atmospheric moisture transport from the Amazon basin, while the warm coastal Brazil Current may also play an important role as an evaporative moisture source for LLCSs over the central and western La Plata basin.

  1. Realized gains from block-plot coastal Douglas-fir trials in the northern Oregon Cascades

    Science.gov (United States)

    Terrence Z. Ye; Keith J.S. Jayawickrama; J. Bradley. St. Clair

    2010-01-01

    Realized gains for coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) were evaluated using data collected from 15-year-old trees from five field trials planted in large block plots in the northern Oregon Cascades. Three populations with different genetic levels (elite--high predicted gain; intermediate--moderate predicted gain; and an...

  2. Gain attenuation of gated framing camera

    International Nuclear Information System (INIS)

    Xiao Shali; Liu Shenye; Cao Zhurong; Li Hang; Zhang Haiying; Yuan Zheng; Wang Liwei

    2009-01-01

    The theoretic model of framing camera's gain attenuation is analyzed. The exponential attenuation curve of the gain along the pulse propagation time is simulated. An experiment to measure the coefficient of gain attenuation based on the gain attenuation theory is designed. Experiment result shows that the gain follows an exponential attenuation rule with a quotient of 0.0249 nm -1 , the attenuation coefficient of the pulse is 0.00356 mm -1 . The loss of the pulse propagation along the MCP stripline is the leading reason of gain attenuation. But in the figure of a single stripline, the gain dose not follow the rule of exponential attenuation completely, instead, there is a gain increase at the stripline bottom. That is caused by the reflection of the pulse. The reflectance is about 24.2%. Combining the experiment and theory, which design of the stripline MCP can improved the gain attenuation. (authors)

  3. Optimal weight gain in obese and overweight pregnant Japanese women.

    Science.gov (United States)

    Hirooka-Nakama, Junko; Enomoto, Kimiko; Sakamaki, Kentaro; Kurasawa, Kentaro; Miyagi, Etsuko; Aoki, Shigeru

    2018-03-20

    We aimed to determine the optimal gestational weight gain (GWG) in Japanese women with a Body Mass Index (BMI) ≥25 kg/m 2 . The present retrospective study investigated singleton pregnancies in 6,781 Japanese women registered in the Japan Society of Obstetrics and Gynecology system in 2013. We divided overweight and obese women into four GWG categories based on the Institute of Medicine (IOM) recommended: weight loss, small weight gain, within IOM criteria, and above IOM criteria. The adjusted odds ratios and predicted probabilities of maternal and neonatal outcomes of interest with weight change were calculated. In overweight women, GWG was associated with neonatal birth weight. In the loss and small gain subgroups, there was a significant increase in small for gestational age (SGA) and low birth weight neonates (LBW). Predicted probabilities showed the lowest risk was observed in a weight gain of 0 kg; the risk sharply increased at a gain of 11.5 kg. In obese women, weight gain increased the prevalence of large for gestational age (LGA) neonates; however; SGA was not associated with GWG. Predicted probabilities showed an increase in the risk with weight gain. The observed optimal GWG was 0 to 11.5 kg in overweight, and weight loss in obese, pregnant Japanese women.

  4. Divisive gain modulation of motoneurons by inhibition optimizes muscular control

    DEFF Research Database (Denmark)

    Vestergaard, Mikkel; Berg, Rune W.

    2015-01-01

    unclear whether the motoneuron gain, i.e., the slope of the transformation between synaptic input and spiking output, is also modulated to reduce variability in force. To address this issue, we use turtle hindlimb scratching as a model for fine motor control, since this behavior involves precise limb...... movement to rub the location of somatic nuisance touch. We recorded intracellularly from motoneurons in a reduced preparation where the limbs were removed to increase mechanical stability and the motor nerve activity served as a surrogate for muscle force. We found that not only is the gain of motoneurons...

  5. Review of health and productivity gains from better IEQ

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2000-08-01

    The available scientific data suggest that existing technologies and procedures can improve indoor environmental quality (IEQ) in a manner that significantly increases productivity and health. While there is considerable uncertainty in the estimates of the magnitudes of productivity gains that may be obtained, the projected gains are very large. For the U.S., the estimated potential annual savings and productivity gains are $6 to $14 billion from reduced respiratory disease, $2 to $4 billion from reduced allergies and asthma, $10 to $30 billion from reduced sick building syndrome symptoms, and $20 to $160 billion from direct improvements in worker performance that are unrelated to health. Productivity gains that are quantified and demonstrated could serve as a strong stimulus for energy efficiency measures that simultaneously improve the indoor environment.

  6. Study on high gain broadband optical parametric chirped pulse amplification

    International Nuclear Information System (INIS)

    Zhang, S.K.; Fujita, M.; Yamanaka, C.; Yoshida, H.; Kodama, R.; Fujita, H.; Nakatsuka, M.; Izawa, Y.

    2000-01-01

    Optical parametric chirped pulse amplification has apparent advantages over the current schemes for high energy ultrashort pulse amplification. High gain in a single pass amplification, small B-integral, low heat deposition, high contrast ratio and, especially the extremely broad gain bandwidth with large-size crystals available bring people new hope for over multi-PW level at which the existing Nd:glass systems suffered difficulties. In this paper we present simulation and experimental studies for a high gain optical parametric chirped pulse amplification system which may be used as a preamplifier to replace the current complicated regenerative system or multi-pass Ti:sapphire amplifiers. Investigations on the amplification bandwidth and gain with BBO are performed. Analysis and discussions are also given. (author)

  7. Compensation of propagation loss of surface plasmon polaritons with a finite-thickness dielectric gain layer

    International Nuclear Information System (INIS)

    Zhang, Xin; Liu, Haitao; Zhong, Ying

    2012-01-01

    We theoretically study the compensation of propagation loss of surface plasmon polaritons (SPPs) with the use of a finite-thickness dielectric layer with optical gain. The impacts of the gain coefficient, the gain-layer thickness and the wavelength on the loss compensation and the field distribution of the SPP mode are systematically explored with a fully vectorial method. Abnormal behaviors for the loss compensation as the gain-layer thickness increases are found and explained. Critical values of the gain coefficient and of the corresponding gain-layer thickness for just compensating the propagation loss are provided. Our results show that as the SPP propagation loss is fully compensated with a gain coefficient at a reasonably low level, the gain layer is still thin enough to ensure a large exterior SPP field at the gain-layer/air interface, which is important for achieving a strong light–matter interaction for applications such as bio-chemical sensing. (paper)

  8. Review of High Gain FELs

    International Nuclear Information System (INIS)

    Shintake, Tsumoru

    2007-01-01

    For understanding on basic radiation mechanism of the high-gain FEL based on SASE, the author presents electron-crystal interpretation of FEL radiation. In the electron-crystal, electrons are localized at regularly spaced multi-layers, which represents micro-bunching, whose spacing is equal to the radiation wavelength, and the multi-layers are perpendicular to beam axis, thus, diffracted wave creates Bragg's spots in forward and backward directions. Due to the Doppler's effect, frequency of the back-scattered wave is up-converted, generates forwardly focused X-ray. The Bragg's effect contributes focusing the X-ray beam into a spot, thus peak power becomes extremely higher by factor of typically 107. This is the FEL radiation. As well known, the total numbers of scattered photons in Bragg's spots is equal to the total elastic scattering photons from the atoms contained in the crystal. Therefore, total power in the FEL laser is same as the spontaneous radiation power from the undulator for the same beam parameter. The FEL radiation phenomenon is simple interference effect. In today's presentations, we use the laser pointer, and we frequently experience difficulty in pointing precisely or steadily in one place on the screen, since the laser spot is very small and does not spread. Exactly same to this, X-ray FEL is a highly focused beam, and pointing stability dominates productivity of experiment, thus we need special care on beam stability from linear accelerator

  9. Time Difference Amplifier with Robust Gain Using Closed-Loop Control

    Science.gov (United States)

    Nakura, Toru; Mandai, Shingo; Ikeda, Makoto; Asada, Kunihiro

    This paper presents a Time Difference Amplifier (TDA) that amplifies the input time difference into the output time difference. Cross coupled chains of variable delay cells with the same number of stages are applicable for TDA, and the gain is adjusted via the closed-loop control. The TDA was fabricated using 65nm CMOS and the measurement results show that the time difference gain is 4.78 at a nominal power supply while the designed gain is 4.0. The gain is stable enough to be less than 1.4% gain shift under ±10% power supply voltage fluctuation.

  10. Polarization dependence of the optical modal gain in ZnO

    International Nuclear Information System (INIS)

    Kim, Bumjin; Kyhm, Kwangseuk; Cho, Chaeryong

    2010-01-01

    The modal gain spectrum due to the electron-hole plasma in ZnO was measured using a variable stripe length method. A modal gain contour map for energy and stripe length allowed the modal gain saturation to be analyzed in terms of the spectral and the stripe length dependences. The modal gain was observed to be more significant in the TE mode than in the TM mode due to the polarization asymmetry of the wurtzite structure. We also found that the degree of polarization are enhanced as the stripe length increased, despite of modal gain saturation.

  11. Extensive intron gain in the ancestor of placental mammals

    Science.gov (United States)

    2011-01-01

    Background Genome-wide studies of intron dynamics in mammalian orthologous genes have found convincing evidence for loss of introns but very little for intron turnover. Similarly, large-scale analysis of intron dynamics in a few vertebrate genomes has identified only intron losses and no gains, indicating that intron gain is an extremely rare event in vertebrate evolution. These studies suggest that the intron-rich genomes of vertebrates do not allow intron gain. The aim of this study was to search for evidence of de novo intron gain in domesticated genes from an analysis of their exon/intron structures. Results A phylogenomic approach has been used to analyse all domesticated genes in mammals and chordates that originated from the coding parts of transposable elements. Gain of introns in domesticated genes has been reconstructed on well established mammalian, vertebrate and chordate phylogenies, and examined as to where and when the gain events occurred. The locations, sizes and amounts of de novo introns gained in the domesticated genes during the evolution of mammals and chordates has been analyzed. A significant amount of intron gain was found only in domesticated genes of placental mammals, where more than 70 cases were identified. De novo gained introns show clear positional bias, since they are distributed mainly in 5' UTR and coding regions, while 3' UTR introns are very rare. In the coding regions of some domesticated genes up to 8 de novo gained introns have been found. Intron densities in Eutheria-specific domesticated genes and in older domesticated genes that originated early in vertebrates are lower than those for normal mammalian and vertebrate genes. Surprisingly, the majority of intron gains have occurred in the ancestor of placentals. Conclusions This study provides the first evidence for numerous intron gains in the ancestor of placental mammals and demonstrates that adequate taxon sampling is crucial for reconstructing intron evolution. The

  12. A Search for Supersymmetry with new kinematic variables in proton-proton Collisions at $\\sqrt{s}=7$ TeV with the ATLAS Detector at the Large Hadron Collider

    CERN Document Server

    Bain, Travis

    A search for Supersymmetry is presented. The search is done with final states containing jets, missing transverse energy and no leptons, using 4.7 $fb^{-1}$ of proton-proton collision data at $\\sqrt{s}=7$ TeV recorded by the ATLAS detector at the Large Hadron Collider. The analysis is carried out using new kinematic variables in two distinct signal regions with and without $b$-jet tagging. No significant excess above the Standard Model background expectation is observed, and limits are set on the Supersymmetry models. The results are interpreted as limits on the minimal supergravity framework, as well as a simplified Supersymmetry model of gluino pair-production.

  13. Gestational weight gain among minority adolescents predicts term birth weight.

    Science.gov (United States)

    Ekambaram, Maheswari; Irigoyen, Matilde; DeFreitas, Johelin; Rajbhandari, Sharina; Geaney, Jessica Lynn; Braitman, Leonard Edward

    2018-03-07

    In adolescents, there is limited evidence on the independent and additive effect of prepregnancy body mass index (BMI) and gestational weight gain on infant birth weight. Data also show that this effect may vary by race. We sought to examine the impact of maternal prepregnancy BMI and gestational weight gain on birth weight and risk of large for gestational age (LGA) in term newborns of minority adolescent mothers. This was a retrospective cohort study of 411 singleton live term infants born to mothers ≤ 18 years. Data were abstracted from electronic medical records. Gestational weight gain was related to infant birth weight (ρ = 0.36, P gain, gestational age and Hispanic ethnicity were independent predictors of birth weight, controlling for maternal age, BMI, parity, tobacco/drug use and preeclampsia. The probability of having an LGA infant increased with weight gain [adjusted odds ratio (aOR) 1.14, 95% confidence interval (CI) 1.07-1.21] but not with BMI. Mothers who gained weight in excess of 2009 Institute of Medicine (IOM) recommendations had a greater risk of having an LGA infant compared to those who gained within recommendations (aOR 5.7, 95% CI 1.6-19.5). Minority adolescents with greater gestational weight gain had infants with higher birth weight and greater risk of LGA; BMI was not associated with either outcome. Further studies are needed to examine the applicability of the 2009 BMI-specific IOM gestational weight gain recommendations to adolescents in minority populations.

  14. Variability Bugs:

    DEFF Research Database (Denmark)

    Melo, Jean

    . Although many researchers suggest that preprocessor-based variability amplifies maintenance problems, there is little to no hard evidence on how actually variability affects programs and programmers. Specifically, how does variability affect programmers during maintenance tasks (bug finding in particular......)? How much harder is it to debug a program as variability increases? How do developers debug programs with variability? In what ways does variability affect bugs? In this Ph.D. thesis, I set off to address such issues through different perspectives using empirical research (based on controlled...... experiments) in order to understand quantitatively and qualitatively the impact of variability on programmers at bug finding and on buggy programs. From the program (and bug) perspective, the results show that variability is ubiquitous. There appears to be no specific nature of variability bugs that could...

  15. No further gain can be achieved by calculating Disease Activity Score in 28 joints with high-sensitivity assay of C-reactive protein because of high intraindividual variability of C-reactive protein: A cross-sectional study and theoretical consideration.

    Science.gov (United States)

    Hansen, Inger M J; Emamifar, Amir; Andreasen, Rikke A; Antonsen, Steen

    2017-01-01

    Disease Activity Score in 28 joints (DAS28) is commonly used to evaluate disease activity of rheumatoid arthritis (RA) and is a guide to treatment decision.The aim of this study was to evaluate the impact of lower reporting limit for C-reactive protein (CRP), with respect to intraindividual biological variability, on the calculation of DAS28 and subsequent patient classification.This study consists of 2 sections: a theoretical consideration discussing the performance of CRP in calculating DAS28 taking intraindividual biological variation and lower reporting limit for CRP into account and a cross-sectional study of RA patients applying our theoretical results. Therefore, we calculated DAS28 twice, with the actual CRP values and CRP = 9 mg/L, the latter to elucidate the positive effects of reducing the lower reporting limit of CRP from <10 to <3 mg/L.Lower-reporting limit of <10 mg/L leads to overestimate DAS28. However, reducing lower reporting limit for CRP to <3 mg/L results in optimizing DAS28 calculation. Further lowering of reporting limit for CRP to <3 mg/L does not increase the precision of DAS28 owing to the relatively large intraindividual biological variation.Five hundred twelve patients were included. There was a significant difference between recalculated and patients DAS28 (P < 0.001). One hundred nine patients had DAS28 deviation (compatible to remission to low: 66, low to moderate: 39. and moderate to high: 4).Owing to significant impact of intraindividual biologic variation on DAS28 and patient classification, special attention should be paid to calculate DAS28 when CRP values are within normal range. Furthermore, we conclude that results of different studies evaluating DAS28 and treatment response are not comparable if the reporting limits of CRP are unknown.

  16. Gain scheduling using the Youla parameterization

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    1999-01-01

    Gain scheduling controllers are considered in this paper. The gain scheduling problem where the scheduling parameter vector cannot be measured directly, but needs to be estimated is considered. An estimation of the scheduling vector has been derived by using the Youla parameterization. The use...... in connection with H_inf gain scheduling controllers....

  17. Determination of the STIS CCD Gain

    Science.gov (United States)

    Riley, Allyssa; Monroe, TalaWanda; Lockwood, Sean

    2016-09-01

    This report summarizes the analysis and absolute gain results of the STIS Cycle 23 special calibration program 14424 that was designed to measure the gain of amplifiers A, C and D at nominal gain settings of 1 and 4 e-/DN. We used the mean-variance technique and the results indicate a mean-variance technique.

  18. Turning value chains into social gains in Southeast Asia | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Turning value chains into social gains in Southeast Asia. Global value chains, which now form the largest share of the world's trade, involve producers and enterprises that produce goods as inputs for other producers. In Southeast Asian countries, these industries employ large numbers of low-skilled workers, particularly ...

  19. Megawatt wind turbines gaining momentum

    International Nuclear Information System (INIS)

    Oehlenschlaeger, K.; Madsen, B.T.

    1996-01-01

    Through the short history of the modern wind turbine, electric utilities have made it amply clear that they have held a preference for large scale wind turbines over smaller ones, which is why wind turbine builders through the years have made numerous attempts develop such machines - machines that would meet the technical, aesthetic and economic demands that a customer would require. Considerable effort was put into developing such wind turbines in the early 1980s. There was the U.S. Department of Energy's MOD 1-5 program, which ranged up to 3.2 MW, Denmark's Nibe A and B, 630 kW turbine and the 2 MW Tjaereborg machine, Sweden's Naesudden, 3 MW, and Germany's Growian, 3 MW. Most of these were dismal failures, though some did show the potential of MW technology. (au)

  20. The Role of Morphology and Electronic Chain Aggregation on the Optical Gain Properties of Semiconducting Conjugated Polymers

    Science.gov (United States)

    Lampert, Zachary Evan

    thresholds and large net gains are highly desirable. In this thesis, we also discuss novel routes we developed for enhancement of ASE performance in MEH-PPV thin film planar waveguides. The first technique relied on improving the distribution of the TE0 guided mode in the CP gain layer through optimization of waveguide architecture. This was achieved by fabricating symmetric heterostructure waveguides formed from a core layer of MEH-PPV sandwiched between an SiO2 buffer and index matched poly(methyl methacrylate) (PMMA) cover layer. Relative to asymmetric waveguides of Si(100)/SiO2/MEH-PPV/Air, symmetric waveguides exhibited increased optical confinement and reduced propagation loss enabling lower ASE threshold (40%) and higher net gain (50%). Independent of device architecture and degree of aggregation in the films, we discovered that optical gain is also highly dependent on the excitation conditions, specifically the temporal width of the pump laser pulses. A 400% increase in net gain was achieved under transient (25 picosecond pulses), compared to quasi-steady state (8 nanosecond pulses), excitation conditions. This large difference is attributed to low pumping efficiency and increased non-radiative recombination under ns pumping, which reduces the emission cross-section resulting in a net decrease in gain. The gain values we achieved in the ps regime are to the best of our knowledge the largest gain values reported to date for thin conjugated polymer films measured using the variable stripe length (VSL) technique. Films pumped in the transient regime also required 30 times less pump energy density to reach threshold in comparison with films pumped in the quasi-steady state regime, although the excited state densities were essentially the same. These results demonstrate that the pumping efficiency, and hence generation rate of excited states in a gain medium, can be dramatically increased by using pump laser pulses that are shorter than the exciton luminescence lifetime

  1. Advanced automated gain adjustments for in-vivo ultrasound imaging

    DEFF Research Database (Denmark)

    Moshavegh, Ramin; Hemmsen, Martin Christian; Martins, Bo

    2015-01-01

    Automatic gain adjustments are necessary on the state-of-the-art ultrasound scanners to obtain optimal scan quality, while reducing the unnecessary user interactions with the scanner. However, when large anechoic regions exist in the scan plane, the sudden and drastic variation of attenuations in....... Wilcoxon signed-rank test was then applied to the ratings provided by radiologists. The average VAS score was highly positive 12.16 (p-value: 2.09 x 10-23) favoring the gain-adjusted scans with the proposed algorithm....

  2. Ultra-high gain diffusion-driven organic transistor

    Science.gov (United States)

    Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

    2016-01-01

    Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal–semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics. PMID:26829567

  3. Enhancing optical gains in Si nanocrystals via hydrogenation and cerium ion doping

    International Nuclear Information System (INIS)

    Wang, Dong-Chen; Li, Yan-Li; Song, Sheng-Chi; Guo, Wen-Ping; Lu, Ming; Chen, Jia-Rong

    2014-01-01

    We report optical gain enhancements in Si nanocrystals (Si-NCs) via hydrogenation and Ce 3+ ion doping. Variable stripe length technique was used to obtain gains. At 0.3 W/cm 2 pumping power density of pulsed laser, net gains were observed together with gain enhancements after hydrogenation and/or Ce 3+ ion doping; gains after loss corrections were between 89.52 and 341.95 cm −1 ; and the photoluminescence (PL) lifetime was found to decrease with the increasing gain enhancement. At 0.04 W/cm 2 power density, however, no net gain was found and the PL lifetime increased with the increasing PL enhancement. The results were discussed according to stimulated and spontaneous excitation and de-excitation mechanisms of Si-NCs.

  4. Experience gained in gamma spectroscopy

    International Nuclear Information System (INIS)

    Jeanmaire, L.

    1960-01-01

    There are two types of method which make it possible to estimate the internal contamination of individuals. On the one hand these are the indirect techniques based on measurements of the excreted products, on the other there are the direct techniques in which attempts are made to measure directly the radio-activity existing in the organism. We propose to give a few of the results obtained by the direct method using equipment built by the Commissariat a l'Energie Atomique. The apparatus consists of a γ spectrometer. It includes: 1) A crystal of sodium iodide 20 cm in diameter and 10 cm high. The large size of this crystal ensures a good sensitivity and makes it possible to carry out rapid measurements. 2) A 25 channel type SAE 25 selector which classifies the pulses according to their amplitude. It is therefore possible to distinguish between γ rays of varying energy. 3) A comparatively very light radiation protection, consisting of only 5 cm thickness of lead which diminishes the ambient γ ray intensity to a sufficient level for the majority of the measurements. A certain collimation is thus obtained which makes it possible to localise the source approximately and to reduce the undesirable effects of external contamination. (author) [fr

  5. Controlling morphology and chain aggregation in semiconducting conjugated polymers: the role of solvent on optical gain in MEH-PPV.

    Science.gov (United States)

    Lampert, Zach E; Reynolds, C Lewis; Papanikolas, John M; Aboelfotoh, M Osama

    2012-10-25

    We report the results of a detailed investigation that addresses the influence of polymer morphology and chain aggregation, as controlled by the chemical nature of the solvent, on the optical gain properties of the conjugated polymer poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV). Using the variable stripe length technique in the picosecond regime, we have extensively studied the optical gain performance of asymmetric planar waveguides formed with thin MEH-PPV films spin-cast from concentrated chlorobenzene (CB) and tetrahydrofuran (THF) solutions onto thermally oxidized silicon substrates. CB and THF solvents were chosen based on their known ability to promote and effectively limit aggregate formation, respectively. Very large net gain coefficients are demonstrated, reaching values of 330 and 365 cm(-1), respectively, when optically pumping the waveguides with a maximum energy density of 85 μJ/cm(2). Our results clearly demonstrate that polymer morphology, and hence, the chain conformation dependence of the degree of aggregation in the films as controlled by the solvent, has minimal impact on the net gain. Moreover, the waveguides exhibit low loss coefficients of 10-20 cm(-1) at the ASE wavelength. These results question the importance of polymer morphology and aggregate formation in polymer-based optical devices operating at high excitation densities in the stimulated emission regime as would be characteristic of lasers and optical amplifiers.

  6. Postcessation weight gain concern as a barrier to smoking cessation: Assessment considerations and future directions.

    Science.gov (United States)

    Germeroth, Lisa J; Levine, Michele D

    2018-01-01

    Concern about postcessation weight gain may be one potential barrier to quitting smoking. In this 'mini-review' of recent literature, we summarize findings on the relationship between postcessation weight gain concern and smoking cessation, and evaluate varied use of postcessation weight gain concern assessments and potential moderators of the postcessation weight gain concern-cessation association. We conducted a search using the terms "smoking" OR "smoking cessation" AND "weight concern" for articles published between January 1, 2011 and December 31, 2016. We identified 17 studies assessing postcessation weight gain concern, seven of which evaluated the postcessation weight gain concern-cessation association. The relationship between postcessation weight gain concern and smoking cessation was mixed. Recent studies varied in their assessments of postcessation weight gain concern, many of which were not validated and assessed correlates of this construct. Studies varied in their adjustment of demographic (e.g., sex), smoking-specific (e.g., smoking level), and weight-specific (e.g., body mass index) variables. The use of non-validated assessments and variability in testing covariates/moderators may contribute to conflicting results regarding the postcessation weight gain concern-cessation relationship. We recommend validating an assessment of postcessation weight gain concern, maintaining vigilance in testing and reporting covariates/moderators, and investigating trajectories of this construct over time and by smoking status to inform future assessment and intervention efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Influences of finite gain bandwidth on pulse propagation in parabolic fiber amplifiers with distributed gain profiles

    International Nuclear Information System (INIS)

    Zhao Jia-Sheng; Li Pan; Chen Xiao-Dong; Feng Su-Juan; Mao Qing-He

    2012-01-01

    The evolutions of the pulses propagating in decreasing and increasing gain distributed fiber amplifiers with finite gain bandwidths are investigated by simulations with the nonlinear Schrödinger equation. The results show that the parabolic pulse propagations in both the decreasing and the increasing gain amplifiers are restricted by the finite gain bandwidth. For a given input pulse, by choosing a small initial gain coefficient and gain variation rate, the whole gain for the pulse amplification limited by the gain bandwidth may be higher, which is helpful for the enhancement of the output linearly chirped pulse energy. Compared to the decreasing gain distributed fiber amplifier, the increasing gain distributed amplifier may be more conducive to suppress the pulse spectral broadening and increase the critical amplifier length for achieving a larger output linearly chirped pulse energy

  8. Energy Gaining Windows for Residental Buildings

    DEFF Research Database (Denmark)

    Kragh, Jesper; Laustsen, Jacob Birck; Svendsen, Svend

    2008-01-01

    This paper presents some of the research done during the last 8 years at the Technical University of Denmark developing improved low-energy window solutions. The focus has been on maximizing the net energy gain of windows for residential buildings. The net energy gain of windows is the solar gain...... minus the heat loss integrated over the heating season. It is assumed that in northern cold climates all of the solar gain during the heating season can be utilized for space heating. Problems with overheating in the summer period must be solved with overhang or moveable solar shading devices. Two...... and longer durability of the window. The glazing in these fiber reinforced polyester windows is both unsealed and sealed triple glazing units. To increase the net energy gain slim frame profiles have been developed to increase the glazing area and thereby the solar gain. The challenge when developing slim...

  9. Pulsating variables

    International Nuclear Information System (INIS)

    1989-01-01

    The study of stellar pulsations is a major route to the understanding of stellar structure and evolution. At the South African Astronomical Observatory (SAAO) the following stellar pulsation studies were undertaken: rapidly oscillating Ap stars; solar-like oscillations in stars; 8-Scuti type variability in a classical Am star; Beta Cephei variables; a pulsating white dwarf and its companion; RR Lyrae variables and galactic Cepheids. 4 figs

  10. The role of gestational diabetes, pre-pregnancy body mass index and gestational weight gain on the risk of newborn macrosomia: results from a prospective multicentre study.

    Science.gov (United States)

    Alberico, Salvatore; Montico, Marcella; Barresi, Valentina; Monasta, Lorenzo; Businelli, Caterina; Soini, Valentina; Erenbourg, Anna; Ronfani, Luca; Maso, Gianpaolo

    2014-01-15

    It is crucial to identify in large population samples the most important determinants of excessive fetal growth. The aim of the study was to evaluate the independent role of pre-pregnancy body mass index (BMI), gestational weight gain and gestational diabetes on the risk of macrosomia. A prospective study collected data on mode of delivery and maternal/neonatal outcomes in eleven Hospitals in Italy. Multiple pregnancies and preterm deliveries were excluded. The sample included 14109 women with complete records. Associations between exposure variables and newborn macrosomia were analyzed using Pearson's chi squared test. Multiple logistic regression models were built to assess the independent association between potential predictors and macrosomia. Maternal obesity (adjusted OR 1.7, 95% CI 1.4-2.2), excessive gestational weight gain (adjusted OR 1.9, 95% CI 1.6-2.2) and diabetes (adjusted OR 2.1, 95% CI 1.5-3.0 for gestational; adjusted OR 3.0, 95% CI 1.2-7.6 for pre-gestational) resulted to be independent predictors of macrosomia, when adjusted for other recognized risk factors. Since no significant interaction was found between pre-gestational BMI and gestational weight gain, excessive weight gain should be considered an independent risk factor for macrosomia. In the sub-group of women affected by gestational or pre-gestational diabetes, pre-gestational BMI was not significantly associated to macrosomia, while excessive pregnancy weight gain, maternal height and gestational age at delivery were significantly associated. In this sub-population, pregnancy weight gain less than recommended was not significantly associated to a reduction in macrosomia. Our findings indicate that maternal obesity, gestational weight gain excess and diabetes should be considered as independent risk factors for newborn macrosomia. To adequately evaluate the clinical evolution of pregnancy all three variables need to be carefully assessed and monitored.

  11. Measurement of Antenna Bore-Sight Gain

    Science.gov (United States)

    Fortinberry, Jarrod; Shumpert, Thomas H.

    2016-01-01

    The absolute or free-field gain of a simple antenna can be approximated using standard antenna theory formulae or for a more accurate prediction, numerical methods may be employed to solve for antenna parameters including gain. Both of these methods will result in relatively reasonable estimates but in practice antenna gain is usually verified and documented via measurements and calibration. In this paper, a relatively simple and low-cost, yet effective means of determining the bore-sight free-field gain of a VHF/UHF antenna is proposed by using the Brewster angle relationship.

  12. Directional amplifier in an optomechanical system with optical gain

    Science.gov (United States)

    Jiang, Cheng; Song, L. N.; Li, Yong

    2018-05-01

    Directional amplifiers are crucial nonreciprocal devices in both classical and quantum information processing. Here we propose a scheme for realizing a directional amplifier between optical and microwave fields based on an optomechanical system with optical gain, where an active optical cavity and two passive microwave cavities are coupled to a common mechanical resonator via radiation pressure. The two passive cavities are coupled via hopping interaction to facilitate the directional amplification between the active and passive cavities. We obtain the condition of achieving optical directional amplification and find that the direction of amplification can be controlled by the phase differences between the effective optomechanical couplings. The effects of the gain rate of the active cavity and the effective coupling strengths on the maximum gain of the amplifier are discussed. We show that the noise added to this amplifier can be greatly suppressed in the large cooperativity limit.

  13. Patterns of intron gain and conservation in eukaryotic genes

    Directory of Open Access Journals (Sweden)

    Wolf Yuri I

    2007-10-01

    Full Text Available Abstract Background: The presence of introns in protein-coding genes is a universal feature of eukaryotic genome organization, and the genes of multicellular eukaryotes, typically, contain multiple introns, a substantial fraction of which share position in distant taxa, such as plants and animals. Depending on the methods and data sets used, researchers have reached opposite conclusions on the causes of the high fraction of shared introns in orthologous genes from distant eukaryotes. Some studies conclude that shared intron positions reflect, almost entirely, a remarkable evolutionary conservation, whereas others attribute it to parallel gain of introns. To resolve these contradictions, it is crucial to analyze the evolution of introns by using a model that minimally relies on arbitrary assumptions. Results: We developed a probabilistic model of evolution that allows for variability of intron gain and loss rates over branches of the phylogenetic tree, individual genes, and individual sites. Applying this model to an extended set of conserved eukaryotic genes, we find that parallel gain, on average, accounts for only ~8% of the shared intron positions. However, the distribution of parallel gains over the phylogenetic tree of eukaryotes is highly non-uniform. There are, practically, no parallel gains in closely related lineages, whereas for distant lineages, such as animals and plants, parallel gains appear to contribute up to 20% of the shared intron positions. In accord with these findings, we estimated that ancestral introns have a high probability to be retained in extant genomes, and conversely, that a substantial fraction of extant introns have retained their positions since the early stages of eukaryotic evolution. In addition, the density of sites that are available for intron insertion is estimated to be, approximately, one in seven basepairs. Conclusion: We obtained robust estimates of the contribution of parallel gain to the observed

  14. Weight gain following treatment of hyperthyroidism.

    Science.gov (United States)

    Dale, J; Daykin, J; Holder, R; Sheppard, M C; Franklyn, J A

    2001-08-01

    Patients frequently express concern that treating hyperthyroidism will lead to excessive weight gain. This study aimed to determine the extent of, and risk factors for, weight gain in an unselected group of hyperthyroid patients. We investigated 162 consecutive hyperthyroid patients followed for at least 6 months. Height, weight, clinical features, biochemistry and management were recorded at each clinic visit. Documented weight gain was 5.42 +/- 0.46 kg (mean +/- SE) and increase in BMI was 8.49 +/- 0.71%, over a mean 24.2 +/- 1.6 months. Pre-existing obesity, Graves' disease causing hyperthyroidism, weight loss before presentation and length of follow-up each independently predicted weight gain. Patients treated with thionamides or radioiodine gained a similar amount of weight (thionamides, n = 87, 5.16 +/- 0.63 kg vs. radioiodine, n = 62, 4.75 +/- 0.57 kg, P = 0.645), but patients who underwent thyroidectomy (n = 13) gained more weight (10.27 +/- 2.56 kg vs. others, P = 0.007). Development of hypothyroidism (even transiently) was associated with weight gain (never hypothyroid, n = 102, 4.57 +/- 0.52 kg, transiently hypothyroid, n = 29, 5.37 +/- 0.85 kg, on T4, n = 31, 8.06 +/- 1.42 kg, P = 0.014). This difference remained after correcting for length of follow-up. In the whole cohort, weight increased by 3.95 +/- 0.40 kg at 1 year (n = 144) to 9.91 +/- 1.62 kg after 4 years (n = 27) (P = 0.008), representing a mean weight gain of 3.66 +/- 0.44 kg/year. We have demonstrated marked weight gain after treatment of hyperthyroidism. Pre-existing obesity, a diagnosis of Graves' disease and prior weight loss independently predicted weight gain and weight continued to rise with time. Patients who became hypothyroid, despite T4 replacement, gained most weight.

  15. Cognitive Variability

    Science.gov (United States)

    Siegler, Robert S.

    2007-01-01

    Children's thinking is highly variable at every level of analysis, from neural and associative levels to the level of strategies, theories, and other aspects of high-level cognition. This variability exists within people as well as between them; individual children often rely on different strategies or representations on closely related problems…

  16. Maximum gain of Yagi-Uda arrays

    DEFF Research Database (Denmark)

    Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.

    1971-01-01

    Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

  17. Gain Shift Corrections at Chi-Nu

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Tristan Brooks [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Massachusetts, Lowell, MA (United States). Dept. of Physics and Applied Physics; Devlin, Matthew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-30

    Ambient conditions have the potential to cause changes in liquid scintillator detector gain that vary with time and temperature. These gain shifts can lead to poor resolution in both energy as well as pulse shape discrimination. In order to correct for these shifts in the Chi-Nu high energy array, a laser system has been developed for calibration of the pulse height signals.

  18. Nonunity gain minimal-disturbance measurement

    DEFF Research Database (Denmark)

    Sabuncu, Metin; Mišta, L.; Fiurášek, J.

    2007-01-01

    We propose and experimentally demonstrate an optimal nonunity gain Gaussian scheme for partial measurement of an unknown coherent state that causes minimal disturbance of the state. The information gain and the state disturbance are quantified by the noise added to the measurement outcomes...

  19. Efficiency gains, bounds, and risk in finance

    NARCIS (Netherlands)

    Sarisoy, Cisil

    2015-01-01

    This thesis consists of three chapters. The first chapter analyzes efficiency gains in the estimation of expected returns based on asset pricing models and examines the economic implications of such gains in portfolio allocation exercises. The second chapter provides nonparametric efficiency bounds

  20. Evaluating realized genetic gains from tree improvement.

    Science.gov (United States)

    J.B. St. Clair

    1993-01-01

    Tree improvement has become an essential part of the management of forest lands for wood production, and predicting yields and realized gains from forests planted with genetically-improved trees will become increasingly important. This paper discusses concepts of tree improvement and genetic gain important to growth and yield modeling, and reviews previous studies of...

  1. Large Neighborhood Search

    DEFF Research Database (Denmark)

    Pisinger, David; Røpke, Stefan

    2010-01-01

    Heuristics based on large neighborhood search have recently shown outstanding results in solving various transportation and scheduling problems. Large neighborhood search methods explore a complex neighborhood by use of heuristics. Using large neighborhoods makes it possible to find better...... candidate solutions in each iteration and hence traverse a more promising search path. Starting from the large neighborhood search method,we give an overview of very large scale neighborhood search methods and discuss recent variants and extensions like variable depth search and adaptive large neighborhood...

  2. Suspended graphene variable capacitor

    OpenAIRE

    AbdelGhany, M.; Mahvash, F.; Mukhopadhyay, M.; Favron, A.; Martel, R.; Siaj, M.; Szkopek, T.

    2016-01-01

    The tuning of electrical circuit resonance with a variable capacitor, or varactor, finds wide application with the most important being wireless telecommunication. We demonstrate an electromechanical graphene varactor, a variable capacitor wherein the capacitance is tuned by voltage controlled deflection of a dense array of suspended graphene membranes. The low flexural rigidity of graphene monolayers is exploited to achieve low actuation voltage in an ultra-thin structure. Large arrays compr...

  3. Training feed-forward neural networks with gain constraints

    Science.gov (United States)

    Hartman

    2000-04-01

    Inaccurate input-output gains (partial derivatives of outputs with respect to inputs) are common in neural network models when input variables are correlated or when data are incomplete or inaccurate. Accurate gains are essential for optimization, control, and other purposes. We develop and explore a method for training feedforward neural networks subject to inequality or equality-bound constraints on the gains of the learned mapping. Gain constraints are implemented as penalty terms added to the objective function, and training is done using gradient descent. Adaptive and robust procedures are devised for balancing the relative strengths of the various terms in the objective function, which is essential when the constraints are inconsistent with the data. The approach has the virtue that the model domain of validity can be extended via extrapolation training, which can dramatically improve generalization. The algorithm is demonstrated here on artificial and real-world problems with very good results and has been advantageously applied to dozens of models currently in commercial use.

  4. Decomposition of potential efficiency gains from hospital mergers in Greece.

    Science.gov (United States)

    Flokou, Angeliki; Aletras, Vassilis; Niakas, Dimitris

    2017-12-01

    This paper evaluates the technical efficiency of 71 Greek public hospitals and examines potential efficiency gains from 13 candidate mergers among them. Efficiency assessments are performed using bootstrapped Data Envelopment Analysis (DEA) whilst merger analysis is conducted by applying the Bogetoft and Wang methodology which allows the overall potential merger gains to be decomposed into three main components of inefficiency, namely technical (or learning), scope (or harmony) and scale (or size) effects. Thus, the analysis provides important insights not only on the magnitude of the potential total efficiency gains but also on their sources. The overall analysis is conducted in the context of a complete methodological framework where methods for outlier detection, returns to scale identification, and bias corrections for DEA estimations are also applied. Mergers are analyzed under the assumptions of constant, variable and non-decreasing returns to scale in an input oriented DEA model with three inputs and three outputs. The main finding of the study indicates that almost all mergers show substantial potential room for efficiency improvement, which is mainly attributed to the pre-merger technical inefficiencies of the individual hospitals and therefore it might be possible to be achieved without the need of implementing full-scale mergers. The same -though, at a lower extent- applies to the harmony effect whilst the size effect shows marginal or even negative gains.

  5. Gain control mechanisms in spinal motoneurons

    Directory of Open Access Journals (Sweden)

    Michael David Johnson

    2014-07-01

    Full Text Available Motoneurons provide the only conduit for motor commands to reach muscles. For many years, motoneurons were in fact considered to be little more than passive wires. Systematic studies in the past 25 years however have clearly demonstrated that the intrinsic electrical properties of motoneurons are under strong neuromodulatory control via multiple sources. The discovery of potent neuromodulation from the brainstem and its ability to change the gain of motoneurons shows that the passive view of the motor output stage is no longer tenable. A mechanism for gain control at the motor output stage makes good functional sense considering our capability of generating an enormous range of forces, from very delicate (e.g. putting in a contact lens to highly forceful (emergency reactions. Just as sensory systems need gain control to deal with a wide dynamic range of inputs, so to might motor output need gain control to deal with the wide dynamic range of the normal movement repertoire. Two problems emerge from the potential use of the brainstem monoaminergic projection to motoneurons for gain control. First, the projection is highly diffuse anatomically, so that independent control of the gains of different motor pools is not feasible. In fact, the system is so diffuse that gain for all the motor pools in a limb likely increases in concert. Second, if there is a system that increases gain, probably a system to reduce gain is also needed. In this review, we summarize recent studies that show local inhibitory circuits within the spinal cord, especially reciprocal and recurrent inhibition, have the potential to solve both of these problems as well as constitute another source of gain modulation.

  6. Design issues for a laboratory high gain fusion facility

    International Nuclear Information System (INIS)

    Hogan, W.J.

    1987-01-01

    In an inertial fusion laboratory high gain facility, experiments will be carried out with up to 1000 MJ of thermonuclear yield. The experiment area of such a facility will include many systems and structures that will have to operate successfully in the difficult environment created by the sudden large energy release. This paper estimates many of the nuclear effects that will occur, discusses the implied design issues and suggests possible solutions so that a useful experimental facility can be built. 4 figs

  7. Application of gain scheduling to the control of batch bioreactors

    Science.gov (United States)

    Cardello, Ralph; San, Ka-Yiu

    1987-01-01

    The implementation of control algorithms to batch bioreactors is often complicated by the inherent variations in process dynamics during the course of fermentation. Such a wide operating range may render the performance of fixed gain PID controllers unsatisfactory. In this work, a detailed study on the control of batch fermentation is performed. Furthermore, a simple batch controller design is proposed which incorporates the concept of gain-scheduling, a subclass of adaptive control, with oxygen uptake rate as an auxiliary variable. The control of oxygen tension in the biorector is used as a vehicle to convey the proposed idea, analysis and results. Simulation experiments indicate significant improvement in controller performance can be achieved by the proposed approach even in the presence of measurement noise.

  8. A low power automatic gain control loop for a receiver

    Energy Technology Data Exchange (ETDEWEB)

    Li Guofeng; Geng Zhiqing; Wu Nanjian, E-mail: nanjian@red.semi.ac.c [State Key Laboratory for Super lattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2010-09-15

    This paper proposes a new structure to lower the power consumption of a variable gain amplifier (VGA) and keep the linearity of the VGA unchanged. The structure is used in a high rate amplitude-shift keying (ASK) based IF-stage. It includes an automatic gain control (AGC) loop and ASK demodulator. The AGC mainly consists of six-stage VGAs. The IF-stage is realized in 0.18 {mu}m CMOS technology. The measurement results show that the power consumption of the whole system is very low. The system consumes 730 {mu}A while operating at 1.8 V. The minimum ASK signal the system could detect is 0.7 mV (peak to peak amplitude). (semiconductor integrated circuits)

  9. Optimal weight gain in triplet pregnancies.

    Science.gov (United States)

    Johnston, Robert C; Erfani, Hadi; Shamshirsaz, Amir A; Spiel, Melissa; Ravangard, Sam F; Shaman, Majid; Allaf, M Baraa; Shamshirsaz, Alireza A; Haeri, Sina

    2017-08-01

    To identify appropriate weight gain in triplet gestations, which may aid in reducing the risk of perinatal morbidity within this high-risk cohort. This retrospective cohort study evaluated all non-anomalous triplet pregnancies between 23 and 40 weeks' gestation resulting in live births at five tertiary-care medical centers between 1991 and 2011. Subjects were divided by pre-pregnancy BMI into underweight, normal-weight, overweight, and obese groups, and then stratified by low (gain (≥1.5 lbs/week). Primary outcomes included spontaneous preterm birth and preeclampsia. We included 116 mothers and 348 corresponding neonates for final analysis. The incidence of preeclampsia and preterm delivery less than 32 weeks' gestation was 37% and 41%, respectively. The incidence of preeclampsia increased with weight gain per week, but was not statistically different from subjects who gained less weight. We found no statistical correlation between weight gain per week and preterm delivery. We found no association between preeclampsia or preterm delivery and increasing weight gain in triplet pregnancies. The association with increased risk for preeclampsia was predominantly due to BMI effect. Based on the current study, recommendations for optimal weight gain in mothers with triplet gestations could not be defined.

  10. Personality type influence the gestational weight gain.

    Science.gov (United States)

    Franik, Grzegorz; Lipka, Nela; Kopyto, Katarzyna; Kopocińska, Joanna; Owczarek, Aleksander; Sikora, Jerzy; Madej, Paweł; Chudek, Jerzy; Olszanecka-Glinianowicz, Magdalena

    2017-08-01

    Pregnancy is frequently followed by the development of obesity. Aside from psychological factors, hormonal changes influence weight gain in pregnant women. We attempted to assess the potential association between personality type and the extent of gestational weight gain. The study group involved 773 women after term delivery (age 26.3 ± 3.9 years, body mass before pregnancy 61.2 ± 11.1 kg). Weight gain during pregnancy was calculated by using self-reported body mass prior to and during the 38th week of pregnancy. Personality type was assessed using the Polish version of the Framingham Type A Behavior Patterns Questionnaire (adapted by Juczynski). Two hundred forty-six (31.8%) study subjects represented type A personalities, 272 (35.2%) type B and 255 (33.0%) an indirect type. Gestational weight gain was related to the behavior patterns questionnaire score and age. In women gain was higher than in women with type B behavior of the same age. In women >30, the gestational weight gain was larger for type B personalities. Type A personality and increased urgency in younger pregnant women increases the risk of developing obesity during pregnancy in women below 30 years old. A higher level of competitiveness demonstrates a risk factor of excessive weight gain during pregnancy regardless of age.

  11. Controlling gain one photon at a time

    Science.gov (United States)

    Schwartz, Gregory W; Rieke, Fred

    2013-01-01

    Adaptation is a salient property of sensory processing. All adaptational or gain control mechanisms face the challenge of obtaining a reliable estimate of the property of the input to be adapted to and obtaining this estimate sufficiently rapidly to be useful. Here, we explore how the primate retina balances the need to change gain rapidly and reliably when photons arrive rarely at individual rod photoreceptors. We find that the weakest backgrounds that decrease the gain of the retinal output signals are similar to those that increase human behavioral threshold, and identify a novel site of gain control in the retinal circuitry. Thus, surprisingly, the gain of retinal signals begins to decrease essentially as soon as background lights are detectable; under these conditions, gain control does not rely on a highly averaged estimate of the photon count, but instead signals from individual photon absorptions trigger changes in gain. DOI: http://dx.doi.org/10.7554/eLife.00467.001 PMID:23682314

  12. Intrinsic gain modulation and adaptive neural coding.

    Directory of Open Access Journals (Sweden)

    Sungho Hong

    2008-07-01

    Full Text Available In many cases, the computation of a neural system can be reduced to a receptive field, or a set of linear filters, and a thresholding function, or gain curve, which determines the firing probability; this is known as a linear/nonlinear model. In some forms of sensory adaptation, these linear filters and gain curve adjust very rapidly to changes in the variance of a randomly varying driving input. An apparently similar but previously unrelated issue is the observation of gain control by background noise in cortical neurons: the slope of the firing rate versus current (f-I curve changes with the variance of background random input. Here, we show a direct correspondence between these two observations by relating variance-dependent changes in the gain of f-I curves to characteristics of the changing empirical linear/nonlinear model obtained by sampling. In the case that the underlying system is fixed, we derive relationships relating the change of the gain with respect to both mean and variance with the receptive fields derived from reverse correlation on a white noise stimulus. Using two conductance-based model neurons that display distinct gain modulation properties through a simple change in parameters, we show that coding properties of both these models quantitatively satisfy the predicted relationships. Our results describe how both variance-dependent gain modulation and adaptive neural computation result from intrinsic nonlinearity.

  13. Improving Genetic Gain with Genomic Selection in Autotetraploid Potato

    Directory of Open Access Journals (Sweden)

    Anthony T. Slater

    2016-11-01

    Full Text Available Potato ( L. breeders consider a large number of traits during cultivar development and progress in conventional breeding can be slow. There is accumulating evidence that some of these traits, such as yield, are affected by a large number of genes with small individual effects. Recently, significant efforts have been applied to the development of genomic resources to improve potato breeding, culminating in a draft genome sequence and the identification of a large number of single nucleotide polymorphisms (SNPs. The availability of these genome-wide SNPs is a prerequisite for implementing genomic selection for improvement of polygenic traits such as yield. In this review, we investigate opportunities for the application of genomic selection to potato, including novel breeding program designs. We have considered a number of factors that will influence this process, including the autotetraploid and heterozygous genetic nature of potato, the rate of decay of linkage disequilibrium, the number of required markers, the design of a reference population, and trait heritability. Based on estimates of the effective population size derived from a potato breeding program, we have calculated the expected accuracy of genomic selection for four key traits of varying heritability and propose that it will be reasonably accurate. We compared the expected genetic gain from genomic selection with the expected gain from phenotypic and pedigree selection, and found that genetic gain can be substantially improved by using genomic selection.

  14. To kill a kangaroo: understanding the decision to pursue high-risk/high-gain resources.

    Science.gov (United States)

    Jones, James Holland; Bird, Rebecca Bliege; Bird, Douglas W

    2013-09-22

    In this paper, we attempt to understand hunter-gatherer foraging decisions about prey that vary in both the mean and variance of energy return using an expected utility framework. We show that for skewed distributions of energetic returns, the standard linear variance discounting (LVD) model for risk-sensitive foraging can produce quite misleading results. In addition to creating difficulties for the LVD model, the skewed distributions characteristic of hunting returns create challenges for estimating probability distribution functions required for expected utility. We present a solution using a two-component finite mixture model for foraging returns. We then use detailed foraging returns data based on focal follows of individual hunters in Western Australia hunting for high-risk/high-gain (hill kangaroo) and relatively low-risk/low-gain (sand monitor) prey. Using probability densities for the two resources estimated from the mixture models, combined with theoretically sensible utility curves characterized by diminishing marginal utility for the highest returns, we find that the expected utility of the sand monitors greatly exceeds that of kangaroos despite the fact that the mean energy return for kangaroos is nearly twice as large as that for sand monitors. We conclude that the decision to hunt hill kangaroos does not arise simply as part of an energetic utility-maximization strategy and that additional social, political or symbolic benefits must accrue to hunters of this highly variable prey.

  15. Gain-scheduled Linear Quadratic Control of Wind Turbines Operating at High Wind Speed

    DEFF Research Database (Denmark)

    Østergaard, Kasper Zinck; Stoustrup, Jakob; Brath, Per

    2007-01-01

    This paper addresses state estimation and linear quadratic (LQ) control of variable speed variable pitch wind turbines. On the basis of a nonlinear model of a wind turbine, a set of operating conditions is identified and a LQ controller is designed for each operating point. The controller gains...... are then interpolated linearly to get a control law for the entire operating envelope. A nonlinear state estimator is designed as a combination of two unscented Kalman filters and a linear disturbance estimator. The gain-scheduling variable (wind speed) is then calculated from the output of these state estimators...

  16. Point Information Gain and Multidimensional Data Analysis

    Directory of Open Access Journals (Sweden)

    Renata Rychtáriková

    2016-10-01

    Full Text Available We generalize the point information gain (PIG and derived quantities, i.e., point information gain entropy (PIE and point information gain entropy density (PIED, for the case of the Rényi entropy and simulate the behavior of PIG for typical distributions. We also use these methods for the analysis of multidimensional datasets. We demonstrate the main properties of PIE/PIED spectra for the real data with the examples of several images and discuss further possible utilizations in other fields of data processing.

  17. TCAD simulation of Low Gain Avalanche Detectors

    Science.gov (United States)

    Dalal, Ranjeet; Jain, Geetika; Bhardwaj, Ashutosh; Ranjan, Kirti

    2016-11-01

    In the present work, detailed simulation using Technology Computer Aided Design (TCAD) tool, Silvaco for non-irradiated and irradiated LGAD (Low Gain Avalanche Detector) devices has been carried out. The effects of different design parameters and proton irradiation on LGAD operation are discussed in detail. An already published effective two trap bulk damage model is used to simulate the radiation damage without implementing any acceptor removal term. The TCAD simulation for irradiated LGAD devices produce decreasing gain with increasing fluence, similar to the measurement results. The space charge density and electric field distribution are used to illustrate the possible reasons for the degradation of gain of the irradiated LGAD devices.

  18. TCAD simulation of Low Gain Avalanche Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Dalal, Ranjeet; Jain, Geetika; Bhardwaj, Ashutosh, E-mail: ashutosh.bhardwaj@cern.ch; Ranjan, Kirti

    2016-11-11

    In the present work, detailed simulation using Technology Computer Aided Design (TCAD) tool, Silvaco for non-irradiated and irradiated LGAD (Low Gain Avalanche Detector) devices has been carried out. The effects of different design parameters and proton irradiation on LGAD operation are discussed in detail. An already published effective two trap bulk damage model is used to simulate the radiation damage without implementing any acceptor removal term. The TCAD simulation for irradiated LGAD devices produce decreasing gain with increasing fluence, similar to the measurement results. The space charge density and electric field distribution are used to illustrate the possible reasons for the degradation of gain of the irradiated LGAD devices.

  19. TCAD simulation of Low Gain Avalanche Detectors

    International Nuclear Information System (INIS)

    Dalal, Ranjeet; Jain, Geetika; Bhardwaj, Ashutosh; Ranjan, Kirti

    2016-01-01

    In the present work, detailed simulation using Technology Computer Aided Design (TCAD) tool, Silvaco for non-irradiated and irradiated LGAD (Low Gain Avalanche Detector) devices has been carried out. The effects of different design parameters and proton irradiation on LGAD operation are discussed in detail. An already published effective two trap bulk damage model is used to simulate the radiation damage without implementing any acceptor removal term. The TCAD simulation for irradiated LGAD devices produce decreasing gain with increasing fluence, similar to the measurement results. The space charge density and electric field distribution are used to illustrate the possible reasons for the degradation of gain of the irradiated LGAD devices.

  20. Gains in Life Expectancy Associated with Higher Education in Men.

    Science.gov (United States)

    Bijwaard, Govert E; van Poppel, Frans; Ekamper, Peter; Lumey, L H

    2015-01-01

    Many studies show large differences in life expectancy across the range of education, intelligence, and socio-economic status. As educational attainment, intelligence, and socio-economic status are highly interrelated, appropriate methods are required to disentangle their separate effects. The aim of this paper is to present a novel method to estimate gains in life expectancy specifically associated with increased education. Our analysis is based on a structural model in which education level, IQ at age 18 and mortality all depend on (latent) intelligence. The model allows for (selective) educational choices based on observed factors and on an unobserved factor capturing intelligence. Our estimates are based on information from health examinations of military conscripts born in 1944-1947 in The Netherlands and their vital status through age 66 (n = 39,798). Our empirical results show that men with higher education have lower mortality. Using structural models to account for education choice, the estimated gain in life expectancy for men moving up one educational level ranges from 0.3 to 2 years. The estimated gain in months alive over the observational period ranges from -1.2 to 5.7 months. The selection effect is positive and amounts to a gain of one to two months. Decomposition of the selection effect shows that the gain from selection on (latent) intelligence is larger than the gain from selection on observed factors and amounts to 1.0 to 1.7 additional months alive. Our findings confirm the strong selection into education based on socio-economic status and intelligence. They also show significant higher life expectancy among individuals with higher education after the selectivity of education choice has been taken into account. Based on these estimates, it is plausible therefore that increases in education could lead to increases in life expectancy.

  1. The Impact of Kangaroo Care on Premature Infant Weight Gain.

    Science.gov (United States)

    Evereklian, Melvina; Posmontier, Bobbie

    Preterm births occur among 11.4% of all live infant births. Without steady weight gain, premature infants may experience lengthy hospitalizations, neurodevelopmental deficits and hospital readmissions, which can increase the financial burden on the health care system and their families. The total U.S. health-related costs linked to preterm infant deliveries are estimated at $4.33 billion. Kangaroo care is a feasible practice that can improve preterm infant weight gain. However, this intervention is utilized less often throughout the U.S. due to numerous barriers including a lack of consistent protocols, inadequate knowledge, and decreased level of confidence in demonstrating the proper kangarooing technique. An integrative review was conducted to evaluate the impact of kangaroo care on premature infant weight gain in order to educate nurses about its efficacy among preterm infants. A literature search was conducted using CINAHL, PubMed, Cochrane Reviews, ClinicalKey and Google Scholar. Large volume searches were restricted using appropriate filters and limiters. Most of the evaluated studies determined that weight gain was greater among the kangarooing premature infants. Kangaroo care is a low-tech low-cost modality that can facilitate improved preterm infant weight gain even in low-resource settings. Despite its current efficacy, kangaroo care is not widely utilized due to several barriers including an absence of standardized protocols and a lack of knowledge about its benefits. Kangaroo care can become a widespread formalized practice after nurses and parents learn about the technique and its numerous benefits for premature infants, including its association with improved weight gain. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Active rc filter permits easy trade-off of amplifier gain and sensitivity to gain

    Science.gov (United States)

    Kerwin, W. J.; Shaffer, C. V.

    1968-01-01

    Passive RC network was designed with zeros of transmission in the right half of the complex frequency plane in the feedback loop of a simple negative-gain amplifier. The proper positioning provides any desired trade-off between amplifier gain and sensitivity to amplifier gain.

  3. Detective quantum efficiency gains compared with speed gains for hypersensitized astronomical plates

    International Nuclear Information System (INIS)

    Kaye, A.L.

    1977-01-01

    It is reasonable to assume that gains in detective quantum efficiency (DQE) are far better criteria for assessing the performance of hypersensitizing techniques than gains in speed. It is shown here that gains in speed can be misleading, for some methods of hypersensitization give plates of increased speed but reduced detective quantum efficiency. (author)

  4. Estimation and variable selection for generalized additive partial linear models

    KAUST Repository

    Wang, Li

    2011-08-01

    We study generalized additive partial linear models, proposing the use of polynomial spline smoothing for estimation of nonparametric functions, and deriving quasi-likelihood based estimators for the linear parameters. We establish asymptotic normality for the estimators of the parametric components. The procedure avoids solving large systems of equations as in kernel-based procedures and thus results in gains in computational simplicity. We further develop a class of variable selection procedures for the linear parameters by employing a nonconcave penalized quasi-likelihood, which is shown to have an asymptotic oracle property. Monte Carlo simulations and an empirical example are presented for illustration. © Institute of Mathematical Statistics, 2011.

  5. Associations of neighbourhood walkability indices with weight gain.

    Science.gov (United States)

    Koohsari, Mohammad Javad; Oka, Koichiro; Shibata, Ai; Liao, Yung; Hanibuchi, Tomoya; Owen, Neville; Sugiyama, Takemi

    2018-04-03

    Inconsistent associations of neighbourhood walkability with adults' body weight have been reported. Most studies examining the relationships of walkability and adiposity are cross-sectional in design. We examined the longitudinal relationships of two walkability indices - conventional walkability and space syntax walkability, and their individual components, with weight change among adults over four years. Data were from the Physical Activity in Localities and Community study in Adelaide, Australia. In 2003-2004, 2650 adults living in 154 Census Collection Districts (CCDs) returned baseline questionnaires; in 2007-2008, the follow-up survey was completed by 1098. Participants reported their weight at baseline and at follow-up. Neighbourhood walkability indices were calculated using geographic information systems and space syntax software. Linear marginal models using generalized estimating equations with robust standard errors were fitted to examine associations of the two walkability indices and their individual components with the weight at follow-up, adjusting for baseline weight, socio-demographic variables, and spatial clustering at the level of CCD. The overall mean weight gain over four years was 1.5 kg. The two walkability indices were closely correlated (r = 0.76, p walkability indices and weight change. Among walkability components, there was a marginally significant negative association between space syntax measure of street integration and weight change: one standard deviation increment in street integration was associated with 0.31 kg less weight gain (p = 0.09). Using a prospective study design and a novel space-syntax based measure of walkability, we were not able to identify relationships between neighbourhood walkability with weight gain. This is consistent with other inconclusive findings on the built environment and obesity. Research on the built environment and adults' weight gain may need to consider not just local environments but

  6. Optical properties of nanowire metamaterials with gain

    DEFF Research Database (Denmark)

    Isidio de Lima, Joaquim Junior; Adam, Jost; Rego, Davi

    2016-01-01

    The transmittance, reflectance and absorption of a nanowire metamaterial with optical gain are numerically simulated and investigated. It is assumed that the metamaterial is represented by aligned silver nanowires embedded into a semiconductor matrix, made of either silicon or gallium phosphide....... The gain in the matrix is modeled by adding a negative imaginary part to the dielectric function of the semiconductor. It is found that the optical coefficients of the metamaterial depend on the gain magnitude in a non-trivial way: they can both increase and decrease with gain depending on the lattice...... constant of the metamaterial. This peculiar behavior is explained by the field redistribution between the lossy metal nanowires and the amplifying matrix material. These findings are significant for a proper design of nanowire metamaterials with low optical losses for diverse applications....

  7. Active Microwave Metamaterials Incorporating Ideal Gain Devices

    Directory of Open Access Journals (Sweden)

    Hao Xin

    2010-12-01

    Full Text Available Incorporation of active devices/media such as transistors for microwave and gain media for optics may be very attractive for enabling desired low loss and broadband metamaterials. Such metamaterials can even have gain which may very well lead to new and exciting physical phenomena. We investigate microwave composite right/left-handed transmission lines (CRLH-TL incorporating ideal gain devices such as constant negative resistance. With realistic lumped element values, we have shown that the negative phase constant of this kind of transmission lines is maintained (i.e., left-handedness kept while gain can be obtained (negative attenuation constant of transmission line simultaneously. Possible implementation and challenging issues of the proposed active CRLH-TL are also discussed.

  8. Transient optical gain in germanium quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sangam; Lange, Christoph; Koester, Niko S.; Schaefer, Martin; Kira, Mackillo; Koch, Stephan W. [Faculty of Physics and Materials Sciences Center, Philipps-Universitaet Marburg (Germany); Chrastina, Daniel; Isella, Giovanni; Kaenel, Hans von [CNISM, Como (Italy); L-NESS, Dipartimento di Fisica del Politecnico di Milano, Como (Italy); Sigg, Hans [Laboratory for Micro and Nanotecnology, Paul Scherrer Institut, Villigen PSI (Switzerland)

    2010-07-01

    One of today's most-sought goals in semiconductor technology is the monolithic integration of microelectronics and photonics on Si. Optical gain is, in general, not expected for Si and Ge or its alloys due to the indirect nature of the band gap in this material system. Here, we show that Ge/SiGe QWs show transient optical gain and may thus be used as an optically-pumped amplifier at room temperature. Further, the nonequilibrium effects which govern the relaxation dynamics of the optically injected carrier distributions in this material were observed and analyzed using a microscopic many-body theory. Strong non-equilibrium gain was obtained on a sub-100 fs time scale. Long-lived gain arising from {gamma}-point transitions is overcompensated by a process bearing the character of free carrier absorption.

  9. Genetic Variation in the Leptin Receptor Gene, Leptin, and Weight Gain in Young Dutch Adults

    NARCIS (Netherlands)

    Rossum, van C.T.M.; Hoebee, B.; Baak, van M.A.; Mars, M.; Saris, W.H.M.; Seidell, J.C.

    2003-01-01

    Objective: To investigate the association between leptin levels, polymorphisms in the leptin receptor (LEPR) gene, and weight gain. Research Methods and Procedures: From two large prospective cohorts in The Netherlands (n = 17, 500), we compared the baseline leptin of 259 subjects who had gained an

  10. Genetic factors as predictors of weight gain in young adult Dutch men and women

    NARCIS (Netherlands)

    Rossum, van C.T.M.; Hoebee, B.; Seidell, J.C.; Bouchard, C.; Baak, van M.A.; Groot, de C.P.G.M.; Chagnon, M.; Graaf, de C.; Saris, W.H.M.

    2002-01-01

    OBJECTIVE: To investigate the association between DNA polymorphisms in several candidate genes for obesity and weight gain. Polymorphisms in these genes may contribute to weight gain through effects on energy intake, energy expenditure or adipogenesis. DESIGN AND METHODS: From two large cohorts in

  11. Extreme Variables in Star Forming Regions

    Science.gov (United States)

    Contreras Peña, Carlos Eduardo

    2015-01-01

    The notion that low- to intermediate-mass young stellar objects (YSOs) gain mass at a constant rate during the early stages of their evolution appears to be challenged by observations of YSOs suffering sudden increases of the rate at which they gain mass from their circumstellar discs. Also, this idea that stars spend most of their lifetime with a low accretion rate and gain most of their final mass during short-lived episodes of high accretion bursts, helps to solve some long-standing problems in stellar evolution. The original classification of eruptive variables divides them in two separate subclasses known as FU Orionis stars (FUors) and EX Lupi stars (EXors). In this classical view FUors are at an early evolutionary stage and are still gaining mass from their parent envelopes, whilst EXors are thought to be older objects only surrounded by an accretion disc. The problem with this classical view is that it excludes younger protostars which have higher accretion rates but are too deeply embedded in circumstellar matter to be observed at optical wavelengths. Optically invisible protostars have been observed to display large variability in the near-infrared. These and some recent discoveries of new eruptive variables, show characteristics that can be attributed to both of the optically-defined subclasses of eruptive variables. The new objects have been proposed to be part of a new class of eruptive variables. However, a more accepted scenario is that in fact the original classes only represent two extremes of the same phenomena. In this sense eruptive variability could be explained as arising from one physical mechanism, i.e. unsteady accretion, where a variation in the parameters of such mechanism can cause the different characteristics observed in the members of this class. With the aim of studying the incidence of episodic accretion among young stellar objects, and to characterize the nature of these eruptive variables we searched for high amplitude variability

  12. Analysis and Evaluation of Performance Gains and Tradeoffs for Massive MIMO Systems

    Directory of Open Access Journals (Sweden)

    Saba Qasim Jabbar

    2016-09-01

    Full Text Available Massive MIMO technique offers significant performance gains for the future of wireless communications via improving the spectral efficiency, energy efficiency and the channel quality with simple linear processing such as maximum-ratio transmission (MRT or zero-forcing (ZF by providing each user a large degree of freedom. In this paper, the system performance gains are studied in a multi-cell downlink massive MIMO system under the main considerations such as perfect channel estimation, imperfect channel estimation and the effect of interference among cells due to pilot sequences contamination. Then, mathematical expressions are derived for these gains i.e., spatial multiplexing gain, array gain and spatial diversity gain. After that, essential tradeoffs among these gains are considered under the effect of non-orthogonal interference, these tradeoffs are: spatial diversity gain vs. spatial multiplexing gain and array gain vs. spatial multiplexing gain. Simulation results show that the unbounded number of base station antennas boosts the array gain through concentrating the energy to spatial directions where users are sited, hence diminishing loss in array gain due to pilot contamination. The simulation results reveal also that massive MIMO strengthens the spatial multiplexing gain through increasing the number of served users via the same system resources in spite the effect of inter-cell interference. Finally, the spatial diversity gain is measured in term of outage probability and the simulation results show that raising the number of antennas will improve the outage probability. Meanwhile increasing the number of served users will lead to degrade the outage probability per user due to non-orthogonal interference from other cells.

  13. Envera Variable Compression Ratio Engine

    Energy Technology Data Exchange (ETDEWEB)

    Charles Mendler

    2011-03-15

    technologies are packaged together to provide the greatest gains at the least cost. Aggressive engine downsizing with variable compression ratio and use of the extended Atkinson cycle can provide large fuel economy gains that are exceptionally cost effective. Analysis indicates that a 2.2L supercharged Envera VCR engine can match the torque of a larger V8 engine at 2000 rpm. The VCR engine's high torque value at low engine speed is beneficial for maintaining the driving feel and responsiveness of the larger V8 engine. The Envera VCR engine will attain high efficiency at {approx}100 Nm primarily due to the combination of engine down-sizing and use of the Atkinson cycle. Qualitatively the fuel economy gain realized from down-sizing from a V8 to an Atkinson-cycle I-4 is about twice as large as the benefits from down-sizing from a V8 to a Turbo V6 when evaluated at 100 Nm 2000 rpm.

  14. Renyi information gain on quantum key

    International Nuclear Information System (INIS)

    Brandt, Howard E

    2007-01-01

    The concept of maximum Renyi information gain from quantum key is important in eavesdropping and security analyses of quantum key distribution. It is particularly useful in the design optimization of eavesdropping probes. The present work reviews the quantitative measure of Renyi information gain, its optimization, and application to the design of eavesdropping probes in which single-photon probe states become optimally entangled with the signal states on their way between the legitimate transmitter and receiver

  15. Enhanced Gain in Photonic Crystal Amplifiers

    DEFF Research Database (Denmark)

    Ek, Sara; Semenova, Elizaveta; Hansen, Per Lunnemann

    2012-01-01

    We experimentally demonstrate enhanced gain in the slow-light regime of quantum well photonic crystal amplifiers. A strong gain enhancement is observed with the increase of the group refractive index, due to light slow-down. The slow light enhancement is shown in a amplified spontaneous emission....... These results are promising for short and efficient semiconductor optical amplifiers. This effect will also benefit other devices, such as mode locked lasers....

  16. FEL gain optimisation and spontaneous radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bali, L.M.; Srivastava, A.; Pandya, T.P. [Lucknow Univ. (India)] [and others

    1995-12-31

    Colson have evaluated FEL gains for small deviations from perfect electron beam injection, with radiation of the same polarisation as that of the wiggler fields. We find that for optimum gain the polarisation of the optical field should be the same as that of the spontaneous emission under these conditions. With a helical wiggler the axial oscillations resulting from small departures from perfect electron beam injection lead to injection dependent unequal amplitudes and phases of the spontaneous radiation in the two transverse directions. Viewed along the axis therefore the spontaneous emission is elliptically polarised. The azimuth of the ellipse varies with the difference of phase of the two transverse components of spontaneous emission but the eccentricity remains the same. With planar wigglers the spontaneous emission viewed in the axial direction is linearly polarised, again with an injection dependent azimuth. For optimum coherent gain of a radiation field its polarisation characteristics must be the same as those of the spontaneous radiation with both types of wiggler. Thus, with a helical wiggler and the data reported earlier, an increase of 10% in the FEL gain at the fundamental frequency and of 11% at the fifth harmonic has been calculated in the small gain per pass limit. Larger enhancements in gain may result from more favourable values of input parameters.

  17. Central gain control in tinnitus and hyperacusis

    Directory of Open Access Journals (Sweden)

    Benjamin D Auerbach

    2014-10-01

    Full Text Available Sensorineural hearing loss induced by noise or ototoxic drug exposure reduces the neural activity transmitted from the cochlea to the central auditory system. Despite a reduced cochlear output, neural activity from more central auditory structures is paradoxically enhanced at suprathreshold intensities. This compensatory increase in the central auditory activity in response to the loss of sensory input is referred to as central gain enhancement. Enhanced central gain is hypothesized to be a potential mechanism that gives rise to hyperacusis and tinnitus, two debilitating auditory perceptual disorders that afflict millions of individuals. This review will examine the evidence for gain enhancement in the central auditory system in response to cochlear damage. Further, it will address the potential cellular and molecular mechanisms underlying this enhancement and discuss the contribution of central gain enhancement to tinnitus and hyperacusis. Current evidence suggests that multiple mechanisms with distinct temporal and spectral profiles are likely to contribute to central gain enhancement. Dissecting the contributions of these different mechanisms at different levels of the central auditory system is essential for elucidating the role of central gain enhancement in tinnitus and hyperacusis and, most importantly, the development of novel treatments for these disorders.

  18. Can LENR Energy Gains Exceed 1000?

    Science.gov (United States)

    Nagel, David J.

    2011-03-01

    Energy gain is defined as the energy realized from reactions divided by the energy required to produce those reactions. Low Energy Nuclear Reactions (LENR) have already been measured to significantly exceed the energy gain of 10 projected from ITER,possibly 15 years from now. Electrochemical experiments using the Pd-D system have shown energy gains exceeding 10. Gas phase experiments with the Ni-H system were reported to yield energy gains of over 100. Neither of these reports has been adequately verified or reproduced. However, the question in the title still deserves consideration. If, as thought by many, it is possible to trigger nuclear reactions that yield MeV energies with chemical energies of the order of eV, then the most optimistic expectation is that LENR gains could approach one million. Hence, the very tentative answer to the question above is yes. However, if LENR could be initiated with some energy cost, and then continue to ``burn,'' very high energy gains might be realized. Consider a match and a pile of dry logs. The phenomenon termed ``heat after death'' will be examined to see if it might be the initial evidence for nuclear ``burning.''

  19. Central Gain Control in Tinnitus and Hyperacusis

    Science.gov (United States)

    Auerbach, Benjamin D.; Rodrigues, Paulo V.; Salvi, Richard J.

    2014-01-01

    Sensorineural hearing loss induced by noise or ototoxic drug exposure reduces the neural activity transmitted from the cochlea to the central auditory system. Despite a reduced cochlear output, neural activity from more central auditory structures is paradoxically enhanced at suprathreshold intensities. This compensatory increase in the central auditory activity in response to the loss of sensory input is referred to as central gain enhancement. Enhanced central gain is hypothesized to be a potential mechanism that gives rise to hyperacusis and tinnitus, two debilitating auditory perceptual disorders that afflict millions of individuals. This review will examine the evidence for gain enhancement in the central auditory system in response to cochlear damage. Further, it will address the potential cellular and molecular mechanisms underlying this enhancement and discuss the contribution of central gain enhancement to tinnitus and hyperacusis. Current evidence suggests that multiple mechanisms with distinct temporal and spectral profiles are likely to contribute to central gain enhancement. Dissecting the contributions of these different mechanisms at different levels of the central auditory system is essential for elucidating the role of central gain enhancement in tinnitus and hyperacusis and, most importantly, the development of novel treatments for these disorders. PMID:25386157

  20. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  1. Adaptive Large Neighbourhood Search

    DEFF Research Database (Denmark)

    Røpke, Stefan

    Large neighborhood search is a metaheuristic that has gained popularity in recent years. The heuristic repeatedly moves from solution to solution by first partially destroying the solution and then repairing it. The best solution observed during this search is presented as the final solution....... This tutorial introduces the large neighborhood search metaheuristic and the variant adaptive large neighborhood search that dynamically tunes parameters of the heuristic while it is running. Both heuristics belong to a broader class of heuristics that are searching a solution space using very large...... neighborhoods. The tutorial also present applications of the adaptive large neighborhood search, mostly related to vehicle routing problems for which the heuristic has been extremely successful. We discuss how the heuristic can be parallelized and thereby take advantage of modern desktop computers...

  2. Intra-patient variability of FDG standardized uptake values in mediastinal blood pool, liver, and myocardium during R-CHOP chemotherapy in patients with diffuse large B- cell lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soo Jeong; Yi, Hyun Kyung; Lim, Chae Hong; Cho, Young Seok; Choi, Joon Young; Choe, Yeam Seong; Lee, Kyung Han; Moon, Seung Hwan [Dept. of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2016-12-15

    {sup 18}F-fluorodeoxyglucose (FDG) PET/CT is useful for staging and evaluating treatment response in patients with diffuse large B-cell lymphoma (DLBCL). A five-point scale model using the mediastinal blood pool (MBP) and liver as references is a recommended method for interpreting treatment response. We evaluated the variability in standardized uptake values (SUVs) of the MBP, liver, and myocardium during chemotherapy in patients with DLBCL. We analyzed 60 patients with DLBCL who received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) treatment and underwent baseline, interim, and final FDG PET/CT scans. The FDG uptakes of lymphoma lesions, MBP, liver, and myocardium were assessed, and changes in the MBP and liver SUV and possible associated factors were evaluated. The SUV of the liver did not change significantly during the chemotherapy. However, the SUV{sub mean} of MBP showed a significant change though the difference was small (p = 0.019). SUV{sub mean} of MBP and liver at baseline and interim scans was significantly lower in patients with advanced Ann Arbor stage on diagnosis. The SUV{sub mean} of the MBP and liver was negatively correlated with the volumetric index of lymphoma lesions in baseline scans (r = -0.547, p < 0.001; r = -0.502, p < 0.001). Positive myocardial FDG uptake was more frequently observed in interim and final scans than in the baseline scan, but there was no significant association between the MBP and liver uptake and myocardial uptake. The SUV of the liver was not significantly changed during R-CHOP chemotherapy in patients with DLBCL, whereas the MBP SUV of the interim scan decreased slightly. However, the SUV of the reference organs may be affected by tumor burden, and this should be considered when assessing follow-up scans. Although myocardial FDG uptake was more frequently observed after R-CHOP chemotherapy, it did not affect the SUV of the MBP and liver.

  3. Association between smoking cessation and weight gain in treatment-seeking African Americans.

    Science.gov (United States)

    Tan, Marcia M; Okuyemi, Kolawole S; Resnicow, Ken; Dietz, Noella A; Antoni, Michael H; Webb Hooper, Monica

    2018-06-01

    Research has shown that African Americans gain more than average weight after smoking cessation. However, African Americans have been underrepresented in post-cessation weight gain research. The current study examined 1) the pattern of weight gain and 2) the association between smoking status and weight gain in a sample of African Americans seeking smoking cessation treatment. Data were drawn from a randomized controlled trial testing the efficacy of a 4-week culturally specific smoking cessation cognitive behavioral therapy (CBT) intervention among African American smokers (N = 342). Weight was measured and self-reported smoking status was biochemically verified at baseline, end of counseling, 3-, 6-, and 12-month follow-ups. Random effects multilevel modeling was used to examine weight gain over twelve months post CBT, and a fully unconditional model tested the pattern of weight gain over time. Smoking status was included as a time-varying factor to examine its effect on weight gain, controlling for potential confounding variables. Weight significantly increased among those who remained abstinent over 12 months post CBT [average gain of seven lbs. (three kg)]. Controlling for covariates, abstinence was predictive of the rate of weight gain for those with high weight concern. Weight gain among African American abstainers was comparable to the average post-cessation weight gain observed among the general population. It is possible that exposure to CBT (culturally specific or standard) may have mitigated excessive weight gain. Future research should assess predictors of weight gain in African American smokers to inform future smoking cessation interventions and help elucidate factors that contribute to tobacco- and obesity-related health disparities. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Variable stars

    International Nuclear Information System (INIS)

    Feast, M.W.; Wenzel, W.; Fernie, J.D.; Percy, J.R.; Smak, J.; Gascoigne, S.C.B.; Grindley, J.E.; Lovell, B.; Sawyer Hogg, H.B.; Baker, N.; Fitch, W.S.; Rosino, L.; Gursky, H.

    1976-01-01

    A critical review of variable stars is presented. A fairly complete summary of major developments and discoveries during the period 1973-1975 is given. The broad developments and new trends are outlined. Essential problems for future research are identified. (B.R.H. )

  5. Gain scheduling controller for pitch control of a TRMS system

    Science.gov (United States)

    Bhagyalakshmi, R.; Rashmi, GP; Jaganatha Pandian, B.

    2017-11-01

    Gain scheduling is a control technique which is applied for the control of non-linear systems by using a family of linear controllers at different operating points so as to increase the range of operation of the process. The dynamics of any nonlinear system changes with respect to operating points. These operating points are characterized by one or more variables known as scheduling variables. In such cases, we linearize the system at different equilibrium points. Due to the high amount of non-linearities and complexity in the aerodynamic design, modelling of other unmanned aerial vehicles have been replaced here with twin rotor system. The linearized system is then controlled by using PID controllers which are designed with respect to the obtained operating points. Linearizing of the non-linear system, designing and tuning of PID are being implemented using different MATLAB functions.

  6. Optical gain and gain suppression of quantum-well lasers with valence band mixing

    International Nuclear Information System (INIS)

    Ahn, D.; Chuang, S.L.

    1990-01-01

    The effects of valence band mixing on the nonlinear gains of quantum-well lasers are studied theoretically. The authors' analysis is based on the multiband effective-mass theory and the density matrix formalism with intraband relaxation taken into account. The gain and the gain-suppression coefficient of a quantum-well laser are calculated from the complex optical susceptibility obtained by the density matrix formulation with the theoretical dipole moments obtained from the multiband effective-mass theory. The calculated gain spectrum shows that there are remarkable differences (both in peak amplitude and spectral shape) between our model with valence band mixing and the conventional parabolic band model. The shape of the gain spectrum calculated by the authors' model becomes more symmetric due to intraband relaxation together with nonparabolic energy dispersions and is closer to the experimental observations when compared with the conventional method using the parabolic band model and the multiband effective-mass calculation without intraband relaxation. Both give quite asymmetric gain spectra. Optical intensity in the GaAs active region is estimated by solving rate equations for the stationary states with nonlinear gain suppression. The authors calculate the mode gain for the resonant mode including the gain suppression, which results in spectral hole burning of the gain spectrum

  7. CONDITIONS FOR CSR MICROBUNCHING GAIN SUPPRESSION

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Cheng Ying [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); di Mitri, Simone [Elettra–Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy

    2016-05-01

    The coherent synchrotron radiation (CSR) of a high brightness electron beam traversing a series of dipoles, such as transport arcs, may result in phase space degradation. On one hand, the CSR can perturb electron transverse motion in dispersive regions along the beamline, causing emittance growth. On the other hand, the CSR effect on the longitudinal beam dynamics could result in microbunching gain enhancement. For transport arcs, several schemes have been proposed* to suppress the CSR-induced emittance growth. Similarly, several scenarios have been introduced** to suppress CSR-induced microbunching gain, which however mostly aim for linac-based machines. In this paper we try to provide sufficient conditions for suppression of CSR-induced microbunching gain along a transport arc, analogous to*. Several example lattices are presented, with the relevant microbunching analyses carried out by our semi-analytical Vlasov solver***. The simulation results show that lattices satisfying the proposed conditions indeed have microbunching gain suppressed. We expect this analysis can shed light on lattice design approach that could suppress the CSR-induced microbunching gain.

  8. Optimizing Multireservoir System Operating Policies Using Exogenous Hydrologic Variables

    Science.gov (United States)

    Pina, Jasson; Tilmant, Amaury; Côté, Pascal

    2017-11-01

    Stochastic dual dynamic programming (SDDP) is one of the few available algorithms to optimize the operating policies of large-scale hydropower systems. This paper presents a variant, called SDDPX, in which exogenous hydrologic variables, such as snow water equivalent and/or sea surface temperature, are included in the state space vector together with the traditional (endogenous) variables, i.e., past inflows. A reoptimization procedure is also proposed in which SDDPX-derived benefit-to-go functions are employed within a simulation carried out over the historical record of both the endogenous and exogenous hydrologic variables. In SDDPX, release policies are now a function of storages, past inflows, and relevant exogenous variables that potentially capture more complex hydrological processes than those found in traditional SDDP formulations. To illustrate the potential gain associated with the use of exogenous variables when operating a multireservoir system, the 3,137 MW hydropower system of Rio Tinto (RT) located in the Saguenay-Lac-St-Jean River Basin in Quebec (Canada) is used as a case study. The performance of the system is assessed for various combinations of hydrologic state variables, ranging from the simple lag-one autoregressive model to more complex formulations involving past inflows, snow water equivalent, and winter precipitation.

  9. Energy Gaining Windows for Residental Buildings

    DEFF Research Database (Denmark)

    Kragh, Jesper; Laustsen, Jacob Birck; Svendsen, Svend

    2008-01-01

    window is made of fiber-reinforced plastic (plastic reinforced by fine fibers made of glass). This composite material is a weatherproof material with very low thermal conductivity and high mechanical strength. These properties make the material very suitable for frame profiles due to lower heat loss...... minus the heat loss integrated over the heating season. It is assumed that in northern cold climates all of the solar gain during the heating season can be utilized for space heating. Problems with overheating in the summer period must be solved with overhang or moveable solar shading devices. Two...... and longer durability of the window. The glazing in these fiber reinforced polyester windows is both unsealed and sealed triple glazing units. To increase the net energy gain slim frame profiles have been developed to increase the glazing area and thereby the solar gain. The challenge when developing slim...

  10. Net energy gain from DT fusion

    International Nuclear Information System (INIS)

    Buende, R.

    1985-01-01

    The net energy which can be gained from an energy raw material by means of a certain conversion system is deduced as the figure-of-merit which adequately characterizes the net energy balance of utilizing an energy source. This potential net energy gain is determined for DT fusion power plants. It is represented as a function of the degree of exploitation of the energy raw material lithium ore and is compared with the net energy which can be gained with LW and FBR power plants by exploiting uranium ore. The comparison clearly demonstrates the net energetic advantage of DT fusion. A sensitivity study shows that this holds even if the energy expenditure for constructing and operating is drastically increased

  11. Gain maximization in a probabilistic entanglement protocol

    Science.gov (United States)

    di Lorenzo, Antonio; Esteves de Queiroz, Johnny Hebert

    Entanglement is a resource. We can therefore define gain as a monotonic function of entanglement G (E) . If a pair with entanglement E is produced with probability P, the net gain is N = PG (E) - (1 - P) C , where C is the cost of a failed attempt. We study a protocol where a pair of quantum systems is produced in a maximally entangled state ρm with probability Pm, while it is produced in a partially entangled state ρp with the complementary probability 1 -Pm . We mix a fraction w of the partially entangled pairs with the maximally entangled ones, i.e. we take the state to be ρ = (ρm + wUlocρpUloc+) / (1 + w) , where Uloc is an appropriate unitary local operation designed to maximize the entanglement of ρ. This procedure on one hand reduces the entanglement E, and hence the gain, but on the other hand it increases the probability of success to P =Pm + w (1 -Pm) , therefore the net gain N may increase. There may be hence, a priori, an optimal value for w, the fraction of failed attempts that we mix in. We show that, in the hypothesis of a linear gain G (E) = E , even assuming a vanishing cost C -> 0 , the net gain N is increasing with w, therefore the best strategy is to always mix the partially entangled states. Work supported by CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico, proc. 311288/2014-6, and by FAPEMIG, Fundação de Amparo à Pesquisa de Minas Gerais, proc. IC-FAPEMIG2016-0269 and PPM-00607-16.

  12. Effect of gain nonlinearity in semiconductor lasers

    DEFF Research Database (Denmark)

    Jensen, Niels H.; Christiansen, Peter Leth; Skovgaard, Ove

    1988-01-01

    Semiconductor lasers are modeled by single-mode rate equations with Langevin noise terms and the influence of nonlinear gain is investigated. For cw operation the probability distribution for the carrier number and the photon number in the laser cavity is obtained. The corresponding (2+1)-dimensi......Semiconductor lasers are modeled by single-mode rate equations with Langevin noise terms and the influence of nonlinear gain is investigated. For cw operation the probability distribution for the carrier number and the photon number in the laser cavity is obtained. The corresponding (2...

  13. On the unlimited gain of a nonlinear parametric amplifier

    DEFF Research Database (Denmark)

    Sorokin, Vladislav

    2014-01-01

    The present paper is concerned with analysis of the response of a nonlinear parametric amplifier in abroad range of system parameters, particularly beyond resonance. Such analysis is of particular interestfor micro- and nanosystems, since many small-scale parametric amplifiers exhibit a distinctly...... nonlinearbehavior when amplitude of their response is sufficiently large. The modified method of direct separa-tion of motions is employed to study the considered system. As the result it is obtained that steady-stateamplitude of the nonlinear parametric amplifier response can reach large values in the case...... of arbitrarilysmall amplitude of external excitation, so that the amplifier gain tends to infinity. Very large amplifiergain can be achieved in a broad range of system parameters, in particular when the amplitude of para-metric excitation is comparatively small. The obtained results clearly demonstrate that very...

  14. Genetic parameters and estimated genetic gains in young rubber tree progenies

    Directory of Open Access Journals (Sweden)

    Cecília Khusala Verardi

    2013-04-01

    Full Text Available The objective of this work was to assess the genetic parameters and to estimate genetic gains in young rubber tree progenies. The experiments were carried out during three years, in a randomized block design, with six replicates and ten plants per plot, in three representative Hevea crop regions of the state of São Paulo, Brazil. Twenty-two progenies were evaluated, from three to five years old, for rubber yield and annual girth growth. Genetic gain was estimated with the multi-effect index (MEI. Selection by progenies means provided greater estimated genetic gain than selection based on individuals, since heritability values of progeny means were greater than the ones of individual heritability, for both evaluated variables, in all the assessment years. The selection of the three best progenies for rubber yield provided a selection gain of 1.28 g per plant. The genetic gains estimated with MEI using data from early assessments (from 3 to 5-year-old were generally high for annual girth growth and rubber yield. The high genetic gains for annual girth growth in the first year of assessment indicate that progenies can be selected at the beginning of the breeding program. Population effective size was consistent with the three progenies selected, showing that they were not related and that the population genetic variability is ensured. Early selection with the genetic gains estimated by MEI can be made on rubber tree progenies.

  15. Patterns and Implications of Gene Gain and Loss in the Evolution of Prochlorococcus

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, Alla; Kettler, Gregory C.; Martiny, Adam C.; Huang, Katherine; Zucker, Jeremy; Coleman, Maureen L.; Rodrigue, Sebastien; Chen, Feng; Lapidus, Alla; Ferriera, Steven; Johnson, Justin; Steglich, Claudia; Church, George M.; Richardson, Paul; Chisholm, Sallie W.

    2007-07-30

    membrane synthesis and transport that dominate the flexible genome and set it apart from the core. Besides identifying islands and demonstrating their role throughout the history of Prochlorococcus, reconstruction of past gene gains and losses shows that much of the variability exists at the"leaves of the tree," between the most closely related strains. Finally, the identification of core and flexible genes from this 12-genome comparison is largely consistent with the relative frequency of Prochlorococcus genes found in global ocean metagenomic databases, further closing the gap between our understanding of these organisms in the lab and the wild.

  16. Patterns and implications of gene gain and loss in the evolution of Prochlorococcus.

    Directory of Open Access Journals (Sweden)

    Gregory C Kettler

    2007-12-01

    outer membrane synthesis and transport that dominate the flexible genome and set it apart from the core. Besides identifying islands and demonstrating their role throughout the history of Prochlorococcus, reconstruction of past gene gains and losses shows that much of the variability exists at the "leaves of the tree," between the most closely related strains. Finally, the identification of core and flexible genes from this 12-genome comparison is largely consistent with the relative frequency of Prochlorococcus genes found in global ocean metagenomic databases, further closing the gap between our understanding of these organisms in the lab and the wild.

  17. Sudden Gains during Therapy of Social Phobia

    Science.gov (United States)

    Hofmann, Stefan G.; Schultz, Stefan M.; Meuret, Alicia E.; Moscovitch, David A.; Suvak, Michael

    2006-01-01

    The present study investigated the phenomenon of sudden gains in 107 participants with social phobia (social anxiety disorder) who received either cognitive-behavioral group therapy or exposure group therapy without explicit cognitive interventions, which primarily used public speaking situations as exposure tasks. Twenty-two out of 967…

  18. Causes and Consequences of Interdialytic weight gain

    NARCIS (Netherlands)

    Ipema, Karin J. R.; Kuipers, Johanna; Westerhuis, Ralf; Gaillard, Carlo A. J. M.; Schans, van der Cees P.; Krijnen, Wim P.; Franssen, Casper F. M.

    2016-01-01

    Background/Aims: Higher interdialytic weight gain (IDWG) is associated with higher predialysis blood pressure and increased mortality. IDWG is also increasingly being recognized as an indicator of nutritional status. We studied in detail the associations of various patient factors and nutritional

  19. Visually induced gains in pitch discrimination

    DEFF Research Database (Denmark)

    Møller, Cecilie; Højlund, Andreas; Bærentsen, Klaus B.

    2018-01-01

    Perception is fundamentally a multisensory experience. The principle of inverse effectiveness (PoIE) states how the multisensory gain is maximal when responses to the unisensory constituents of the stimuli are weak. It is one of the basic principles underlying multisensory processing of spatiotem...

  20. Refixation saccades with normal gain values

    DEFF Research Database (Denmark)

    Korsager, Leise Elisabeth Hviid; Faber, Christian Emil; Schmidt, Jesper Hvass

    2017-01-01

    -ocular reflex. However, this partial deficit is in conflict with the current way of interpreting vHIT results in which the vestibular function is classified as either normal or pathological based only on the gain value. Refixation saccades, which are evident signs of vestibulopathy, are not considered...

  1. Gains and losses in nonadditive expected utility

    NARCIS (Netherlands)

    Rakesh, S.; Wakker, P.P.; Machina, M.J.; Munier, B.R.

    1995-01-01

    This paper provides a simple approach for deriving cumulative prospect theory. The key axiom is a cumulative dominance axiom which requires that a prospect be judged more attractive if in it greater gains are more likely and greater losses are less likely. In the presence of this cumulative

  2. Maternal Weight Gain Biosocial Characteristics And Perinatal ...

    African Journals Online (AJOL)

    Objective: Maternal weight gain in pregnancy can offer a good means of assessing the well being of the pregnant mother and by inference, her baby. The cross – sectional prospective study was carried out carried out between November 1996 and December 1997, in Jos University Teaching hospital to assess the influence ...

  3. Measured stimulated Raman gain in methane

    International Nuclear Information System (INIS)

    Lopert, R.B.

    1983-01-01

    This report is about the stimulated Raman effect in methane due to the nu 1 vibration. For various gas pressures between 150 torr and 30 atm, the Raman lineshape function was both experimentally measured and synthesized using a computer model. The stimulated Raman gain was measured by sending a pump laser beam provided by an argon-ion laser and a weak probe beam provided by a tunable dye laser through a cell of methane gas. The stimulated Raman effect caused some of the energy from the pump beam to be transferred to the probe beam. The intensity of the pump beam was low so the gain of the probe beam was on the order of parts per million. A two detector arrangement and a differential amplifier system that had a feedback loop to balance the detectors was constructed to measure the small gains. A detailed description of this detection system that was able to measure gains as small as 0.2 parts per million is provided

  4. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  5. HOW NORMAL IS VARIABLE, OR HOW VARIABLE IS NORMAL

    NARCIS (Netherlands)

    TOUWEN, BCL

    Variability is an important property of the central nervous system, and it shows characteristic changes during infancy and childhood. The large amount of variations in the performance of sensomotor functions in infancy is called indiscriminate or primary variability. During toddling age the child

  6. Variable Selection in Time Series Forecasting Using Random Forests

    Directory of Open Access Journals (Sweden)

    Hristos Tyralis

    2017-10-01

    Full Text Available Time series forecasting using machine learning algorithms has gained popularity recently. Random forest is a machine learning algorithm implemented in time series forecasting; however, most of its forecasting properties have remained unexplored. Here we focus on assessing the performance of random forests in one-step forecasting using two large datasets of short time series with the aim to suggest an optimal set of predictor variables. Furthermore, we compare its performance to benchmarking methods. The first dataset is composed by 16,000 simulated time series from a variety of Autoregressive Fractionally Integrated Moving Average (ARFIMA models. The second dataset consists of 135 mean annual temperature time series. The highest predictive performance of RF is observed when using a low number of recent lagged predictor variables. This outcome could be useful in relevant future applications, with the prospect to achieve higher predictive accuracy.

  7. Heritability of childhood weight gain from birth and risk markers for adult metabolic disease in prepubertal twins.

    LENUS (Irish Health Repository)

    Beardsall, Kathryn

    2009-10-01

    Associations between size at birth, postnatal weight gain, and potential risk for adult disease have been variably explained by in utero exposures or genetic risk that could affect both outcomes. We utilized a twin model to explore these hypotheses.

  8. Treating floodplain lakes of large rivers as study units for variables that vary within lakes; an evaluation using chlorophyll a and inorganic suspended solids data from floodplain lakes of the Upper Mississippi River

    Science.gov (United States)

    Gray, B.R.; Rogala, J.R.; Houser, J.N.

    2013-01-01

    Contiguous floodplain lakes ('lakes') have historically been used as study units for comparative studies of limnological variables that vary within lakes. The hierarchical nature of these studies implies that study variables may be correlated within lakes and that covariate associations may differ not only among lakes but also by spatial scale. We evaluated the utility of treating lakes as study units for limnological variables that vary within lakes based on the criteria of important levels of among-lake variation in study variables and the observation of covariate associations that vary among lakes. These concerns were selected, respectively, to ensure that lake signatures were distinguishable from within-lake variation and that lake-scale effects on covariate associations might provide inferences not available by ignoring those effects. Study data represented chlorophyll a (CHL) and inorganic suspended solids (ISS) data from lakes within three reaches of the Upper Mississippi River. Sampling occurred in summer from 1993 through 2005 (except 2003); numbers of lakes per reach varied from 7 to 19, and median lake area varied from 53 to 101 ha. CHL and ISS levels were modelled linearly, with lake, year and lake x year effects treated as random. For all reaches, the proportions of variation in CHL and ISS attributable to differences among lakes (including lake and lake x year effects) were substantial (range: 18%-73%). Finally, among-lake variation in CHL and ISS was strongly associated with covariates and covariate effects that varied by lakes or lake-years (including with vegetation levels and, for CHL, log(ISS)). These findings demonstrate the utility of treating floodplain lakes as study units for the study of limnological variables and the importance of addressing hierarchy within study designs when making inferences from data collected within floodplain lakes.

  9. Heuristic Portfolio Trading Rules with Capital Gain Taxes

    DEFF Research Database (Denmark)

    Fischer, Marcel; Gallmeyer, Michael

    in some cases. Overlaying simple tax trading heuristics on these trading strategies improves out-of-sample performance. In particular, the 1/N trading strategy's welfare gains improve when a variety of tax trading heuristics are also imposed. For medium to large transaction costs, no trading strategy can...... outperform a 1/N trading strategy augmented with a tax heuristic, not even the most tax- and transaction-cost efficient buy-and-hold strategy. Overall, the best strategy is 1/N augmented with a heuristic that allows for a fixed deviation in absolute portfolio weights. Our results show that the best trading...

  10. Heuristic Portfolio Trading Rules with Capital Gain Taxes

    DEFF Research Database (Denmark)

    Fischer, Marcel; Gallmeyer, Michael

    2016-01-01

    We study the out-of-sample performance of portfolio trading strategies used when an investor faces capital gain taxation and proportional transaction costs. Overlaying simple tax trading heuristics on trading strategies improves out-of-sample performance. For medium to large transaction costs......, no trading strategy can outperform a 1/N trading strategy augmented with a tax heuristic, not even the most tax and transaction cost-efficient buy-and-hold strategy. Overall, the best strategy is 1/N augmented with a heuristic that allows for a fixed deviation in absolute portfolio weights. Our results thus...... show that the best trading strategies balance diversification considerations and tax considerations....

  11. Robust, Gain-Scheduled Control of Wind Turbines

    DEFF Research Database (Denmark)

    Østergaard, Kasper Zinck

    Wind turbines are today large and efficient machines, which are combined into wind farms operating on par with conventional power plants. When looking back, this is significantly different from the status only a few years ago, when wind turbines were sold mainly to private people. This change...... in turbine owners has resulted in a new focus on operational reliability instead of turbine size. This research deals with investigating model-based gain-scheduling control of wind turbines by use of linear parameter varying (LPV) methods. The numerical challenges grow quickly with the model size...

  12. Method and system for edge cladding of laser gain media

    Science.gov (United States)

    Bayramian, Andrew James; Caird, John Allyn; Schaffers, Kathleen Irene

    2014-03-25

    A gain medium operable to amplify light at a gain wavelength and having reduced transverse ASE includes an input surface and an output surface opposing the input surface. The gain medium also includes a central region including gain material and extending between the input surface and the output surface along a longitudinal optical axis of the gain medium. The gain medium further includes an edge cladding region surrounding the central region and extending between the input surface and the output surface along the longitudinal optical axis of the gain medium. The edge cladding region includes the gain material and a dopant operable to absorb light at the gain wavelength.

  13. Noise Induces Biased Estimation of the Correction Gain.

    Directory of Open Access Journals (Sweden)

    Jooeun Ahn

    Full Text Available The detection of an error in the motor output and the correction in the next movement are critical components of any form of motor learning. Accordingly, a variety of iterative learning models have assumed that a fraction of the error is adjusted in the next trial. This critical fraction, the correction gain, learning rate, or feedback gain, has been frequently estimated via least-square regression of the obtained data set. Such data contain not only the inevitable noise from motor execution, but also noise from measurement. It is generally assumed that this noise averages out with large data sets and does not affect the parameter estimation. This study demonstrates that this is not the case and that in the presence of noise the conventional estimate of the correction gain has a significant bias, even with the simplest model. Furthermore, this bias does not decrease with increasing length of the data set. This study reveals this limitation of current system identification methods and proposes a new method that overcomes this limitation. We derive an analytical form of the bias from a simple regression method (Yule-Walker and develop an improved identification method. This bias is discussed as one of other examples for how the dynamics of noise can introduce significant distortions in data analysis.

  14. Pulsating red variables

    International Nuclear Information System (INIS)

    Whitelock, P.A.

    1990-01-01

    The observational characteristics of pulsating red variables are reviewed with particular emphasis on the Miras. These variables represent the last stage in the evolution of stars on the Asymptotic Giant Branch (AGB). A large fraction of the IRAS sources in the Bulge are Mira variables and a subset of these are also OH/IR sources. Their periods range up to 720 days, though most are between 360 and 560 days. At a given period those stars with the highest pulsation amplitudes have the highest mass-loss rates; this is interpreted as evidence for a causal connection between mass-loss and pulsation. It is suggested that once an AGB star has become a Mira it will evolve with increasing pulsation amplitude and mass-loss, but with very little change of luminosity or logarithmic period. 26 refs

  15. Subtractive, divisive and non-monotonic gain control in feedforward nets linearized by noise and delays.

    Science.gov (United States)

    Mejias, Jorge F; Payeur, Alexandre; Selin, Erik; Maler, Leonard; Longtin, André

    2014-01-01

    The control of input-to-output mappings, or gain control, is one of the main strategies used by neural networks for the processing and gating of information. Using a spiking neural network model, we studied the gain control induced by a form of inhibitory feedforward circuitry-also known as "open-loop feedback"-, which has been experimentally observed in a cerebellum-like structure in weakly electric fish. We found, both analytically and numerically, that this network displays three different regimes of gain control: subtractive, divisive, and non-monotonic. Subtractive gain control was obtained when noise is very low in the network. Also, it was possible to change from divisive to non-monotonic gain control by simply modulating the strength of the feedforward inhibition, which may be achieved via long-term synaptic plasticity. The particular case of divisive gain control has been previously observed in vivo in weakly electric fish. These gain control regimes were robust to the presence of temporal delays in the inhibitory feedforward pathway, which were found to linearize the input-to-output mappings (or f-I curves) via a novel variability-increasing mechanism. Our findings highlight the feedforward-induced gain control analyzed here as a highly versatile mechanism of information gating in the brain.

  16. Subtractive, divisive and non-monotonic gain control in feedforward nets linearized by noise and delays

    Directory of Open Access Journals (Sweden)

    Jorge F Mejias

    2014-02-01

    Full Text Available The control of input-to-output mappings, or gain control, is one of the main strategies used by neural networks for the processing and gating of information. Using a spiking neural network model, we studied the gain control induced by a form of inhibitory feedforward circuitry — also known as ’open-loop feedback’ —, which has been experimentally observed in a cerebellum-like structure in weakly electric fish. We found, both analytically and numerically, that this network displays three different regimes of gain control: subtractive, divisive, and non-monotonic. Subtractive gain control was obtained when noise is very low in the network. Also, it was possible to change from divisive to non-monotonic gain control by simply modulating the strength of the feedforward inhibition, which may be achieved via long-term synaptic plasticity. The particular case of divisive gain control has been previously observed in vivo in weakly electric fish. These gain control regimes were robust to the presence of temporal delays in the inhibitory feedforward pathway, which were found to linearize the input-to-output mappings (or f-I curves via a novel variability-increasing mechanism. Our findings highlight the feedforward-induced gain control analyzed here as a highly versatile mechanism of information gating in the brain.

  17. Correlates of motivation to prevent weight gain: a cross sectional survey

    Directory of Open Access Journals (Sweden)

    Breedveld Boudewijn

    2005-03-01

    Full Text Available Abstract Background This study is an application of the theory of planned behaviour (TPB with additional variables to predict the motivations to prevent weight gain. In addition, variations in measures across individuals classified into Precaution Adoption Process stages (PAPM-stages of behaviour change were investigated. Methods A cross-sectional survey among 979 non-obese Dutch adults aged 25–35 years was conducted. Multiple binary logistic regression analysis was conducted to assess the associations of Body Mass Index (BMI, demographic factors and psychosocial variables from the TPB with the intention to prevent weight gain. Differences in BMI, demographic and psychosocial factors between PAPM-stages were explored using one-way analysis of variance and chi-square tests. Results Eighty-five percent of respondents intended to prevent weight gain. Age, attitudes and risk perceptions related to weight gain were the strongest correlates of intention (age: OR = 1.12, 95%CI: 1.04–1.20; attitude OR = 7.91, 95%CI: 5.33–11.74; risk perception OR = 1.24, 95%CI: 1.11–1.38. Significant differences were detected between the PAPM-stages in almost all variables. Notably, perceived behavioural control was lowest among people who had decided to prevent weight gain. Conclusion Messages to influence attitudes towards the prevention of weight gain and risk perception may affect people who are not yet motivated to prevent weight gain. Interventions increasing people's perceived behavioural control in overcoming barriers to prevent weight gain may help people to act on their intentions.

  18. Task complexity and maximal isometric strength gains through motor learning

    Science.gov (United States)

    McGuire, Jessica; Green, Lara A.; Gabriel, David A.

    2014-01-01

    Abstract This study compared the effects of a simple versus complex contraction pattern on the acquisition, retention, and transfer of maximal isometric strength gains and reductions in force variability. A control group (N = 12) performed simple isometric contractions of the wrist flexors. An experimental group (N = 12) performed complex proprioceptive neuromuscular facilitation (PNF) contractions consisting of maximal isometric wrist extension immediately reversing force direction to wrist flexion within a single trial. Ten contractions were completed on three consecutive days with a retention and transfer test 2‐weeks later. For the retention test, the groups performed their assigned contraction pattern followed by a transfer test that consisted of the other contraction pattern for a cross‐over design. Both groups exhibited comparable increases in strength (20.2%, P < 0.01) and reductions in mean torque variability (26.2%, P < 0.01), which were retained and transferred. There was a decrease in the coactivation ratio (antagonist/agonist muscle activity) for both groups, which was retained and transferred (35.2%, P < 0.01). The experimental group exhibited a linear decrease in variability of the torque‐ and sEMG‐time curves, indicating transfer to the simple contraction pattern (P < 0.01). The control group underwent a decrease in variability of the torque‐ and sEMG‐time curves from the first day of training to retention, but participants returned to baseline levels during the transfer condition (P < 0.01). However, the difference between torque RMS error versus the variability in torque‐ and sEMG‐time curves suggests the demands of the complex task were transferred, but could not be achieved in a reproducible way. PMID:25428951

  19. Learning Predictive Interactions Using Information Gain and Bayesian Network Scoring.

    Directory of Open Access Journals (Sweden)

    Xia Jiang

    Full Text Available The problems of correlation and classification are long-standing in the fields of statistics and machine learning, and techniques have been developed to address these problems. We are now in the era of high-dimensional data, which is data that can concern billions of variables. These data present new challenges. In particular, it is difficult to discover predictive variables, when each variable has little marginal effect. An example concerns Genome-wide Association Studies (GWAS datasets, which involve millions of single nucleotide polymorphism (SNPs, where some of the SNPs interact epistatically to affect disease status. Towards determining these interacting SNPs, researchers developed techniques that addressed this specific problem. However, the problem is more general, and so these techniques are applicable to other problems concerning interactions. A difficulty with many of these techniques is that they do not distinguish whether a learned interaction is actually an interaction or whether it involves several variables with strong marginal effects.We address this problem using information gain and Bayesian network scoring. First, we identify candidate interactions by determining whether together variables provide more information than they do separately. Then we use Bayesian network scoring to see if a candidate interaction really is a likely model. Our strategy is called MBS-IGain. Using 100 simulated datasets and a real GWAS Alzheimer's dataset, we investigated the performance of MBS-IGain.When analyzing the simulated datasets, MBS-IGain substantially out-performed nine previous methods at locating interacting predictors, and at identifying interactions exactly. When analyzing the real Alzheimer's dataset, we obtained new results and results that substantiated previous findings. We conclude that MBS-IGain is highly effective at finding interactions in high-dimensional datasets. This result is significant because we have increasingly

  20. An evaluation of FIA's stand age variable

    Science.gov (United States)

    John D. Shaw

    2015-01-01

    The Forest Inventory and Analysis Database (FIADB) includes a large number of measured and computed variables. The definitions of measured variables are usually well-documented in FIA field and database manuals. Some computed variables, such as live basal area of the condition, are equally straightforward. Other computed variables, such as individual tree volume,...

  1. The Gains from Improved Market Efficiency

    DEFF Research Database (Denmark)

    Persson, Karl Gunnar; Ejrnæs, Mette

    faster, violations of the law of one price become smaller and hence less persistent. There were also significant gains from improved market efficiency but that improvement took place after the information ‘regime’ shifted from pre-telegraphic communication to a regime with swift transmission...... of information in an era which developed a sophisticated commercial press and telegraphic communication. Improved market efficiency probably stimulated trade more than falling transport costs......This paper looks at the gains from improved market efficiency in long-distance grain trade in the second half of the 19th century when violations of the law of one price were reduced due to improved information transmission. Two markets, a major export centre, Chicago, and a major importer...

  2. Contrast Gain Control Model Fits Masking Data

    Science.gov (United States)

    Watson, Andrew B.; Solomon, Joshua A.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    We studied the fit of a contrast gain control model to data of Foley (JOSA 1994), consisting of thresholds for a Gabor patch masked by gratings of various orientations, or by compounds of two orientations. Our general model includes models of Foley and Teo & Heeger (IEEE 1994). Our specific model used a bank of Gabor filters with octave bandwidths at 8 orientations. Excitatory and inhibitory nonlinearities were power functions with exponents of 2.4 and 2. Inhibitory pooling was broad in orientation, but narrow in spatial frequency and space. Minkowski pooling used an exponent of 4. All of the data for observer KMF were well fit by the model. We have developed a contrast gain control model that fits masking data. Unlike Foley's, our model accepts images as inputs. Unlike Teo & Heeger's, our model did not require multiple channels for different dynamic ranges.

  3. The gain from improved market efficiency

    DEFF Research Database (Denmark)

    Ejrnæs, Mette; Persson, Karl Gunnar

    2010-01-01

    demand as well as excess supply, which triggered off the tâtonnement process. Over time, adjustments to equilibrium, as measured by the half-life of a shock, became faster and violations of the law of one price become smaller. There were significant gains from improved market efficiency, which took place......This article looks at the gains from improved market efficiency in long-distance grain trade in the second half of the nineteenth century, when violations of the law of one price were reduced due to improved information transmission. Two markets, a major export centre, Chicago, and a major importer......, Liverpool, are analysed. We show that the law of one price equilibrium was an ‘attractor equilibrium'. The implication is that prices converged to that equilibrium in a tâtonnement process. Because of asymmetrically timed information between markets separated by long distances there were periods of excess...

  4. Solar heat gain through vertical cylindrical glass

    Energy Technology Data Exchange (ETDEWEB)

    Kassem, M.A.; Kaseb, S.; El-Refaie, M.F. [Cairo Univ., Mechanical Power Engineering Dept., Cairo (Egypt)

    1999-10-01

    Spaces with nonplanar glazed envelopes are frequently encountered in contemporary buildings. Such spaces represent a problem when calculating the solar heat gain in the course of estimating the cooling or heating load; and hence, sizing of cooling or heating systems. The calculation, using the information currently available in the literature, is tedious and/or approximate. In the present work, the computational procedure for evaluating the solar heat gain to a space having a vertical cylindrical glass envelope is established, and, a computer program is coded to carry out the necessary computations and yield the results in a detailed usable form. The program is versatile and allows for the arbitrary variation of all pertinent parameters. (Author)

  5. Solar heat gain through vertical cylindrical glass

    International Nuclear Information System (INIS)

    Kassem, M.A.; Kaseb, S.; El-Refaie, M.F.

    1999-01-01

    Spaces with nonplanar glazed envelopes are frequently encountered in contemporary buildings. Such spaces represent a problem when calculating the solar heat gain in the course of estimating the cooling or heating load; and hence, sizing of cooling or heating systems. The calculation, using the information currently available in the literature, is tedious and/or approximate. In the present work, the computational procedure for evaluating the solar heat gain to a space having a vertical cylindrical glass envelope is established, and, a computer program is coded to carry out the necessary computations and yield the results in a detailed usable form. The program is versatile and allows for the arbitrary variation of all pertinent parameters. (Author)

  6. Solar heat gain through vertical cylindrical glass

    Energy Technology Data Exchange (ETDEWEB)

    Kassem, M.A.; Kaseb, S.; El-Refaie, M.F. [Cairo Univ., Mechanical Power Engineering Dept., Cairo (Egypt)

    1999-07-01

    Spaces with nonplanar glazed envelopes are frequently encountered in contemporary buildings. Such spaces represent a problem when calculating the solar heat gain in the course of estimating the cooling or heating load; and hence, sizing of cooling or heating systems. The calculation, using the information currently available in the literature, is tedious and/or approximate. In the present work, the computational procedure for evaluating the solar heat gain to a space having a vertical cylindrical glass envelope is established, and, a computer program is coded to carry out the necessary computations and yield the results in a detailed usable form. The program is versatile and allows for the arbitrary variation of all pertinent parameters. (Author)

  7. Brain Gain am Beispiel Österreich

    Directory of Open Access Journals (Sweden)

    Aschbacher Christine

    2016-06-01

    Full Text Available BrainGain is a common trend within the last ten years in Europe and all-over the world. Managers, key players and scientists are allowed to choose wherever they want to work in the world. As there is a lack of qualified individuals for companies and universities, BrainGain has become a necessity, and mostly – the higher educated individuals are moving away according to a better offer elsewhere in the world. Therefore, a lot of expats are moving around with their families. Many times, the lack of integration at the current place, country or city, is the critical success factor for staying or leaving. Furthermore, if the family does not feel happy in the current location, then the manager or scientist will move away or return home and the investment will be lost.

  8. Progress in high gain inertial confinement fusion

    International Nuclear Information System (INIS)

    Sun Jingwen

    2001-01-01

    The author reviews the progress in laboratory high gain inertial confinement fusion (ICF), including ICF capsule physics, high-energy-density science, inertial fusion energy, the National Ignition Facility (NIF) and its design of ignition targets and the peta watt laser breakthrough. High power laser, particle beam, and pulsed power facilities around the world have established the new laboratory field of high-energy- density plasma physics and have furthered development of inertial fusion. New capabilities such as those provided by high-brightness peta watt lasers have enabled the study of matter feasible in conditions previously unachievable on earth. Science and technology developed in inertial fusion research have found near-term commercial use and have enabled steady progress toward the goal of fusion ignition and high gain in the laboratory, and have opened up new fields of study for the 21 st century

  9. Water on fire: Gains from electricity trade

    International Nuclear Information System (INIS)

    Fehr, N.H. von der; Sandsbraaten, L.

    1997-01-01

    In light of the ongoing liberalization of electricity trade in the Nordic countries, and perhaps in Northern Europe, we argue that gains from electricity trade may be different from those traditionally associated with comparative advantages and economics of scale. In particular, we consider gains arising from the exploitation of technological complementaries between hydro and thermal systems. Our theoretical framework highlights essential features of the two systems and allows for an analysis of effects of trade. We study three trading regimes, which may arise either endogenously or because of trade regulations: day-night power exchange, seasonal energy banking and unbalanced trade. The analysis suggests that gradual trade liberalization may be costly. 13 refs, 7 figs

  10. Gaining the Edge: Connecting with the Millennials

    Science.gov (United States)

    2008-12-01

    Cleaver’s and Partridge’s) entered Americans’ living rooms nightly. The Osmond’s and Beatles captivated music of the Boomer’s youth. Powerful...AIR WAR COLLEGE AIR UNIVERSITY GAINING THE EDGE: CONNECTING WITH THE MILLENNIALS by Kay A. Smith, Lt Col, USAF A Research Report Submitted to... the Faculty In Partial Fulfillment of the Graduation Requirements 1 December 2008 DISCLAIMER The views expressed in this academic research

  11. ROMANIA'S EU ACCESSION. GAINS AND LOSSES (I

    Directory of Open Access Journals (Sweden)

    Caba Stefan

    2012-07-01

    Full Text Available EU accession has brought, as expected, many changes in economic, social and cultural domains. An important chapter is the trade dynamics and how this dynamic has been modified over time by changes in the legal status of Romania's relations with certain trading partners. In this paper we present data on trade with countries with which Romania has concluded trade agreements before accession. Data presentation and analysis continues in "Romania's EU accession. Gains and losses (II".

  12. Insights gained through probabilistic risk assessments

    International Nuclear Information System (INIS)

    Hitchler, M.J.; Burns, N.L.; Liparulo, N.J.; Mink, F.J.

    1987-01-01

    The insights gained through a comparison of seven probabilistic risk assessments (PRA) studies (Italian PUN, Sizewell B, Ringhals 2, Millstone 3, Zion 1 and 2, Oconee 3, and Seabrook) included insights regarding the adequacy of the PRA technology utilized in the studies and the potential areas for improvement and insights regarding the adequacy of plant designs and how PRA has been utilized to enhance the design and operation of nuclear power plants

  13. Capital gains taxation under different tax regimes

    OpenAIRE

    Sureth, Caren; Langeleh, Dirk

    2005-01-01

    This paper investigates the influence of different systems of current income and capital gains taxation on investor's decision to either carry out an investment in corporate shares or to invest funds alternatively on the capital market. Three basic tax systems are analyzed, a classical corporate tax system with double taxation of profits on corporate and personal level, a shareholder relief system, that reduces double taxation completely. It can be shown that general analytical solutions for ...

  14. How Subsidiaries Gain Power in Multinational Corporations

    DEFF Research Database (Denmark)

    Mudambi, Ram; Pedersen, Torben; Andersson, Ulf

    2014-01-01

    in multinational firms. Data collected from 2107 foreign-owned subsidiaries in seven European countries is used to test the hypotheses. The results indicate that mutual dependence and dependence imbalance provide strong explanations for subsidiary power. Furthermore, subsidiary power over strategic decisions...... in the MNC is gained through functional power, notably the possession of technological, rather than business-related, power or by the possession of both as they reinforce each other in strengthening the subsidiary's strategic power in the MNC network...

  15. Weight gain in children on oxcarbazepine monotherapy.

    Science.gov (United States)

    Garoufi, Anastasia; Vartzelis, George; Tsentidis, Charalambos; Attilakos, Achilleas; Koemtzidou, Evangelia; Kossiva, Lydia; Katsarou, Eustathia; Soldatou, Alexandra

    2016-05-01

    Studies of the effect of oxcarbazepine (OXC) on body growth of children with epilepsy are rare and their results are controversial. To the contrary, many studies have shown significant weight gain following valproate (VPA) treatment. To prospectively evaluate the effect of OXC monotherapy on growth patterns of children with epilepsy and compare it with the effect of VPA monotherapy. Fifty-nine otherwise healthy children, aged 3.7-15.9 years, with primary generalized, partial or partial with secondary generalization seizure disorder, were included in the study. Twenty six children were placed on OXC and thirty three on VPA monotherapy. Body weight (BW), height and body mass index (BMI) as well as their standard deviation scores (SDS), were evaluated prior to as well as 8 months post initiation of OXC or VPA therapy. Eight months post OXC-treatment, BW, SDS-BW, BMI and SDS-BMI increased significantly. The increase was similar to that observed in the VPA group. An additional 15.4% of children in the OXC group and 21.2% in the VPA group became overweight or obese. The effect of both OXC and VPA therapy on linear growth did not reach statistical significance. Similarly to VPA, OXC monotherapy resulted in a significant weight gain in children with epilepsy. Careful monitoring for excess weight gain along with counseling on adapting a healthy lifestyle should be offered to children on OXC therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. OGJ group earnings show big gain for 1993

    International Nuclear Information System (INIS)

    Beck, R.J.; Sanders, V.

    1994-01-01

    Earnings for Oil and Gas Journal's group of 22 large US oil companies advanced sharply last year, increasing 70.9% from 1992. Group profits totaled $16.1 billion, with the gain stemming largely from lack of one time charges that depressed earnings in 1992. Adoption of new accounting rules associated with future postretirement costs caused the 1992 charges. US exploration and production earnings were mixed, tied in part to oil and gas production volumes. Higher gas prices and production helped boost earnings for a number of companies. But the earnings improvement from gas was offset by reduced oil production and prices. Results from non-U.S. E and P also were mixed. Average worldwide crude oil export prices were down from year earlier levels. However, for some companies this was offset by higher production levels and lower exploration costs. Earnings from refining and marketing were improved from 1992 levels, particularly for non-US operations. Lower feedstock costs, especially in the fourth quarter, helped boost earnings in this sector. Refining earnings gains also flowed from lower costs due to restructuring and an accompanying improvement in operating efficiency. The paper discusses world trends, operations and prices, US exploration and production, non-US E and P, US and non-US refining and marketing, petrochemicals, and the forecast for future demand

  17. Large deviations

    CERN Document Server

    Varadhan, S R S

    2016-01-01

    The theory of large deviations deals with rates at which probabilities of certain events decay as a natural parameter in the problem varies. This book, which is based on a graduate course on large deviations at the Courant Institute, focuses on three concrete sets of examples: (i) diffusions with small noise and the exit problem, (ii) large time behavior of Markov processes and their connection to the Feynman-Kac formula and the related large deviation behavior of the number of distinct sites visited by a random walk, and (iii) interacting particle systems, their scaling limits, and large deviations from their expected limits. For the most part the examples are worked out in detail, and in the process the subject of large deviations is developed. The book will give the reader a flavor of how large deviation theory can help in problems that are not posed directly in terms of large deviations. The reader is assumed to have some familiarity with probability, Markov processes, and interacting particle systems.

  18. Body image and gestational weight gain: a prospective study.

    Science.gov (United States)

    Hill, Briony; Skouteris, Helen; McCabe, Marita; Fuller-Tyszkiewicz, Matthew

    2013-01-01

    Approximately 50% of Australian adult women of childbearing age are overweight or obese, and, when pregnant, the majority gain excessive weight; this is also the case in the United States and other developed nations. High gestational weight gain (GWG) is the strongest predictor of maternal overweight/obesity postbirth and is also associated with an increased risk of childhood obesity. Understanding factors that contribute to excessive GWG is vital in combating obesity. The aim of the current study was to examine whether body image attitudes (eg, feeling fat, attractive, or strong and fit, and salience of weight and shape) predict GWG. Pregnant women, recruited through advertisements on pregnancy online forums and parenting magazines, completed questionnaires assessing body image, demographic variables, and GWG. The Body Attitudes Questionnaire assessed body image in early-to-middle, middle, and late pregnancy (mean of 16.8, 24.7, and 33.0 weeks' gestation, respectively). Total GWG was calculated by subtracting self-reported pre pregnancy weight from self-reported weight at 36.8 weeks' gestation. A total of 150 pregnant women responded to the study's advertisements, and 72% (n = 108) took part. After controlling for pre pregnancy body mass index (BMI), lower attractiveness in early-to-middle pregnancy was associated with higher GWG. In late pregnancy, women who had the lowest feelings of fatness had greater GWG. Body image attitudes earlier in pregnancy did not predict whether GWG recommendations were exceeded. Women of higher BMI were more likely to gain excessive weight. The findings suggest that the type and timing of pregnancy, body attitudes, and the time of pregnancy when they are noted, predict GWG. However, more research in the area is needed, including assessment of the relationship between body image concerns, GWG, and other psychosocial factors. We recommend that midwives monitor body image concerns in pregnancy to help address factors affecting GWG in at

  19. Exponential gain of randomness certified by quantum contextuality

    Science.gov (United States)

    Um, Mark; Zhang, Junhua; Wang, Ye; Wang, Pengfei; Kim, Kihwan

    2017-04-01

    We demonstrate the protocol of exponential gain of randomness certified by quantum contextuality in a trapped ion system. The genuine randomness can be produced by quantum principle and certified by quantum inequalities. Recently, randomness expansion protocols based on inequality of Bell-text and Kochen-Specker (KS) theorem, have been demonstrated. These schemes have been theoretically innovated to exponentially expand the randomness and amplify the randomness from weak initial random seed. Here, we report the experimental evidence of such exponential expansion of randomness. In the experiment, we use three states of a 138Ba + ion between a ground state and two quadrupole states. In the 138Ba + ion system, we do not have detection loophole and we apply a methods to rule out certain hidden variable models that obey a kind of extended noncontextuality.

  20. Hybrid discrete choice models: Gained insights versus increasing effort

    International Nuclear Information System (INIS)

    Mariel, Petr; Meyerhoff, Jürgen

    2016-01-01

    Hybrid choice models expand the standard models in discrete choice modelling by incorporating psychological factors as latent variables. They could therefore provide further insights into choice processes and underlying taste heterogeneity but the costs of estimating these models often significantly increase. This paper aims at comparing the results from a hybrid choice model and a classical random parameter logit. Point of departure for this analysis is whether researchers and practitioners should add hybrid choice models to their suite of models routinely estimated. Our comparison reveals, in line with the few prior studies, that hybrid models gain in efficiency by the inclusion of additional information. The use of one of the two proposed approaches, however, depends on the objective of the analysis. If disentangling preference heterogeneity is most important, hybrid model seems to be preferable. If the focus is on predictive power, a standard random parameter logit model might be the better choice. Finally, we give recommendations for an adequate use of hybrid choice models based on known principles of elementary scientific inference. - Highlights: • The paper compares performance of a Hybrid Choice Model (HCM) and a classical Random Parameter Logit (RPL) model. • The HCM indeed provides insights regarding preference heterogeneity not gained from the RPL. • The RPL has similar predictive power as the HCM in our data. • The costs of estimating HCM seem to be justified when learning more on taste heterogeneity is a major study objective.

  1. Hybrid discrete choice models: Gained insights versus increasing effort

    Energy Technology Data Exchange (ETDEWEB)

    Mariel, Petr, E-mail: petr.mariel@ehu.es [UPV/EHU, Economía Aplicada III, Avda. Lehendakari Aguire, 83, 48015 Bilbao (Spain); Meyerhoff, Jürgen [Institute for Landscape Architecture and Environmental Planning, Technical University of Berlin, D-10623 Berlin, Germany and The Kiel Institute for the World Economy, Duesternbrooker Weg 120, 24105 Kiel (Germany)

    2016-10-15

    Hybrid choice models expand the standard models in discrete choice modelling by incorporating psychological factors as latent variables. They could therefore provide further insights into choice processes and underlying taste heterogeneity but the costs of estimating these models often significantly increase. This paper aims at comparing the results from a hybrid choice model and a classical random parameter logit. Point of departure for this analysis is whether researchers and practitioners should add hybrid choice models to their suite of models routinely estimated. Our comparison reveals, in line with the few prior studies, that hybrid models gain in efficiency by the inclusion of additional information. The use of one of the two proposed approaches, however, depends on the objective of the analysis. If disentangling preference heterogeneity is most important, hybrid model seems to be preferable. If the focus is on predictive power, a standard random parameter logit model might be the better choice. Finally, we give recommendations for an adequate use of hybrid choice models based on known principles of elementary scientific inference. - Highlights: • The paper compares performance of a Hybrid Choice Model (HCM) and a classical Random Parameter Logit (RPL) model. • The HCM indeed provides insights regarding preference heterogeneity not gained from the RPL. • The RPL has similar predictive power as the HCM in our data. • The costs of estimating HCM seem to be justified when learning more on taste heterogeneity is a major study objective.

  2. Variable collimator

    International Nuclear Information System (INIS)

    Richey, J.B.; McBride, T.R.; Covic, J.

    1979-01-01

    This invention describes an automatic variable collimator which controls the width and thickness of X-ray beams in X-ray diagnostic medical equipment, and which is particularly adapted for use with computerized axial tomographic scanners. A two-part collimator is provided which shapes an X-ray beam both prior to its entering an object subject to radiographic analysis and after the attenuated beam has passed through the object. Interposed between a source of radiation and the object subject to radiographic analysis is a first or source collimator. The source collimator causes the X-ray beam emitted by the source of radiation to be split into a plurality of generally rectangular shaped beams. Disposed within the source collimator is a movable aperture plate which may be used to selectively vary the thickness of the plurality of generally rectangular shaped beams transmitted through the source collimator. A second or receiver collimator is interposed between the object subject to radiographic analysis and a series of radiation detectors. The receiver collimator is disposed to receive the attenuated X-ray beams passing through the object subject to radiographic analysis. Located within the receiver collimator are a plurality of movable aperture plates adapted to be displaced relative to a plurality of fixed aperture plates for the purpose of varying the width and thickness of the attenuated X-ray beams transmitted through the object subject to radiographic analysis. The movable aperture plates of the source and receiver collimators are automatically controlled by circuitry which is provided to allow remote operation of the movable aperture plates

  3. Does Asking Make a Difference? Effects of Initiator, Possible Gain, and Risk on Attributed Altruism.

    Science.gov (United States)

    Quigley, Barbara; And Others

    1989-01-01

    Investigates three variables related to attributed altruism: (1) the effects of initiating prosocial behavior; (2) the potential gain or loss for the prosocial actor; and (3) the possible risk for the prosocial actor. Determines that any evidence of selfish motivation detracts from perceived altruism, and that no evidence of selfish motivation…

  4. A model for predicting livemass gain from stocking rate and annual ...

    African Journals Online (AJOL)

    The relationship between livemass gain and stocking rate was established for young beef animals grazing kikuyu and Coastcross II pastures in each of five grazing seasons. The annual rainfall within these seasons ranges from 506mm to 990mm. Relationships between pasture production variables and annual rainfall are ...

  5. Maternal pre-pregnancy body mass index, gestational weight gain influence birth weight.

    Science.gov (United States)

    Zhao, R; Xu, L; Wu, M L; Huang, S H; Cao, X J

    2018-02-01

    Evidence suggests that pre-pregnancy body mass index and gestational weight gain have impact on pregnancy and birth weight, yet whether maternal gestational weight gain has a differential effect on the rates of adverse birth weight among women with different pre-pregnancy body mass index categories are unknown. We selected 1617 children matched with their mothers as study subjects. The subjects were divided into three categories: weight gain below the American Institute of Medicine guidelines, weight gain within the American Institute of Medicine guidelines and weight gain above the American Institute of Medicine guidelines. The prevalence of pre-pregnancy underweight and overweight/obese women was 16.3% and 12.3%. And nearly 15.2% of the women had gestational weight gain below American Institute of Medicine guideline, 52.1% of the women had gestational weight gain above American Institute of Medicine guideline. Maternal overweight and obese was associated with increased risk for macrosomia and large-for-gestational age. Women had gestational weight gain below American Institute of Medicine guideline were more likely to have low birth weight and small-for-gestational age than women who had gestational weight gain within American Institute of Medicine guideline. Furthermore, the risks for macrosomia and large-for-gestational age were increased in women with above American Institute of Medicine guideline. And for women with a normal weight before pregnancy, gestational weight gain above the American Institute of Medicine guidelines were associated with higher rates of macrosomia and large-for-gestational age, compared with the women of similar pre-pregnancy weight category but with gestational weight gain within the American Institute of Medicine guidelines. Women with abnormal pre-pregnancy body mass index and gestational weight gain are at risk for adverse birth weight outcomes. Moreover, gestational weight gain has a differential effect on the rates of adverse

  6. Meal size is a critical driver of weight gain in early childhood

    OpenAIRE

    Syrad, Hayley; Llewellyn, Clare H.; Johnson, Laura; Boniface, David; Jebb, Susan A.; van Jaarsveld, Cornelia H. M.; Wardle, Jane

    2016-01-01

    Larger serving sizes and more frequent eating episodes have been implicated in the rising prevalence of obesity at a population level. This study examines the relative contributions of meal size and frequency to weight gain in a large sample of British children. Using 3-day diet diaries from 1939 children aged 21 months from the Gemini twin cohort, we assessed prospective associations between meal size, meal frequency and weight gain from two to five years. Separate longitudinal analyses demo...

  7. When gains loom larger than losses: reversed loss aversion for small amounts of money.

    Science.gov (United States)

    Harinck, Fieke; Van Dijk, Eric; Van Beest, Ilja; Mersmann, Paul

    2007-12-01

    Previous research has generally shown that people are loss averse; that is, they weigh losses more heavily than gains. In a series of three experiments, we found that for small outcomes, this pattern is reversed, and gains loom larger than losses. We explain this reversal on the basis of (a) the hedonic principle, which states that individuals are motivated to maximize pleasure and to minimize pain, and (b) the assumption that small losses are more easily discounted cognitively than large losses are.

  8. Large for Gestational Age (LGA)

    Science.gov (United States)

    ... mother Other risk factors for having large-for-gestational-age newborns include Maternal obesity Having had previous LGA babies Genetic abnormalities or syndromes (for example, Beckwith-Wiedemann syndrome or Sotos syndrome) Excessive weight gain during pregnancy (the fetus gets more calories as ...

  9. Neutron gain for converging guide tubes

    International Nuclear Information System (INIS)

    Mildner, D.F.R.

    1982-01-01

    The method of acceptance diagrams is used to obtain analytical expressions for the neutron gain of a one-dimensional converging guide tube. It is found that the results are more easily expressed by analyzing the acceptance diagram at the exit of the funnel. The results are compared with those for the straight guide. When both guides have the same dimensions at the guide exit, the converging guide has higher transmitted intensity but with greater divergence of the beam. This analytical method is useful to assess the performance of a converging guide, though numerical computations may be required for detailed analysis of a guide system. (orig.)

  10. Design for logistics to gain competitive advantage

    DEFF Research Database (Denmark)

    Chaudhuri, Atanu; Biskoptsø, Rogvi

    2015-01-01

    . Considering logistical requirements in design of a product which is heavy and bulky and involves significant logistics costs enabled to firm to gain competitiveness. The exercise underscored the importance of understanding logistical requirements, freight costs and dimensional constraints early in the design...... phase which is usually neglected by start-up firms focused on the engineering driven innovativeness of the products. The processes developed along with guidelines facilitate future use which can help such firms to proactively consider logistics requirements at the design stage....

  11. Gasoline sales post minimal gain in 1986

    Energy Technology Data Exchange (ETDEWEB)

    1987-06-22

    Despite the continuing emphasis on conservation and the growing trend to smaller sized automobiles, sales of motor gasoline across Canada posted a gain of 0.4% in 1986. Figures are included in this survey for Canadian motor gasoline sales categorized by province, type of gasoline, and months of 1985 and 1986. Sales of refiners' diesel fuel oil are also categorized by province and by months of 1985 and 1986. Motor gasoline disposition for 1983-1986 is categorized into retail pump sales, road and urban transport, agriculture, public administration, and commercial and other institutional markets. Also included are figures for refiners' propane sales for 1983-1986 by province.

  12. Perspectives used for gaining approval of budgets.

    Science.gov (United States)

    Franks-Joiner, G L

    1990-01-01

    Nurse executives think about problems using a certain perspective which may influence decisions on budgetary matters. The nurse executives' perspective used in decision-making may influence which budget proposals are developed and approved. A study was performed to determine the perspective used by nurse executives in decision-making on supplementary budget item proposals and whether perspective use influenced approval. Findings showed that use of the system view or dual-domain perspective in a proposal may enhance nurse executives' changes of gaining approval.

  13. A 60-dB linear VGA with novel exponential gain approximation

    International Nuclear Information System (INIS)

    Zhou Jiaye; Tan Xi; Wang Junyu; Tang Zhangwen; Min Hao

    2009-01-01

    A CMOS variable gain amplifier (VGA) that adopts a novel exponential gain approximation is presented. No additional exponential gain control circuit is required in the proposed VGA used in a direct conversion receiver. A wide gain control voltage from 0.4 to 1.8 V and a high linearity performance are achieved. The three-stage VGA with automatic gain control (AGC) and DC offset cancellation (DCOC) is fabricated in a 0.18-μm CMOS technology and shows a linear gain range of more than 58-dB with a linearity error less than ±1 dB. The 3-dB bandwidth is over 8 MHz at all gain settings. The measured input-referred third intercept point (IIP3) of the proposed VGA varies from -18.1 to 13.5 dBm, and the measured noise figure varies from 27 to 65 dB at a frequency of 1 MHz. The dynamic range of the closed-loop AGC exceeds 56 dB, where the output signal-to-noise-and-distortion ratio (SNDR) reaches 20 dB. The whole circuit, occupying 0.3 mm 2 of chip area, dissipates less than 3.7 mA from a 1.8-V supply.

  14. Dynamical and biogeochemical control on the decadal variability of ocean carbon fluxes

    Directory of Open Access Journals (Sweden)

    R. Séférian

    2013-04-01

    Full Text Available Several recent observation-based studies suggest that ocean anthropogenic carbon uptake has slowed down due to the impact of anthropogenic forced climate change. However, it remains unclear whether detected changes over the recent time period can be attributed to anthropogenic climate change or rather to natural climate variability (internal plus naturally forced variability alone. One large uncertainty arises from the lack of knowledge on ocean carbon flux natural variability at the decadal time scales. To gain more insights into decadal time scales, we have examined the internal variability of ocean carbon fluxes in a 1000 yr long preindustrial simulation performed with the Earth System Model IPSL-CM5A-LR. Our analysis shows that ocean carbon fluxes exhibit low-frequency oscillations that emerge from their year-to-year variability in the North Atlantic, the North Pacific, and the Southern Ocean. In our model, a 20 yr mode of variability in the North Atlantic air-sea carbon flux is driven by sea surface temperature variability and accounts for ~40% of the interannual regional variance. The North Pacific and the Southern Ocean carbon fluxes are also characterised by decadal to multi-decadal modes of variability (10 to 50 yr that account for 20–40% of the interannual regional variance. These modes are driven by the vertical supply of dissolved inorganic carbon through the variability of Ekman-induced upwelling and deep-mixing events. Differences in drivers of regional modes of variability stem from the coupling between ocean dynamics variability and the ocean carbon distribution, which is set by large-scale secular ocean circulation.

  15. Benchmarking Variable Selection in QSAR.

    Science.gov (United States)

    Eklund, Martin; Norinder, Ulf; Boyer, Scott; Carlsson, Lars

    2012-02-01

    Variable selection is important in QSAR modeling since it can improve model performance and transparency, as well as reduce the computational cost of model fitting and predictions. Which variable selection methods that perform well in QSAR settings is largely unknown. To address this question we, in a total of 1728 benchmarking experiments, rigorously investigated how eight variable selection methods affect the predictive performance and transparency of random forest models fitted to seven QSAR datasets covering different endpoints, descriptors sets, types of response variables, and number of chemical compounds. The results show that univariate variable selection methods are suboptimal and that the number of variables in the benchmarked datasets can be reduced with about 60 % without significant loss in model performance when using multivariate adaptive regression splines MARS and forward selection. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Stability and performance of variable gain controllers with application to a dvd storage drive

    NARCIS (Netherlands)

    Heertjes, M.F.; Steinbuch, M.

    2004-01-01

    This paper deals with the control design for optical storage drives. A nonlinear design is suggested to overcome the tradeoff between disturbance rejection, in the sense of tracking error reduction during low-frequency shock and vibration, and playability, in the sense of sensor noise tracking

  17. 16K CAMAC analyzer memory module for data acquisition with four ADCs with variable conversation gain

    International Nuclear Information System (INIS)

    Nagy, J.Z.

    1985-01-01

    This module containing 16 K . 24 bit CMOS RAM enables four measurements in spectrum or list mode simultaneously. In spectrum mode the RAM can be divided into four segments each in size between 1 and 16 K. (orig.)

  18. IQ Gains in Argentina between 1964 and 1998

    Science.gov (United States)

    Flynn, James R.; Rossi-Case, Lilia

    2012-01-01

    The literature on IQ gains in Latin America is sparse. We estimate gains on Raven's Progressive Matrices in the city of La Plata (Argentina) between 1964 and 1998. The gains are robust at the top of the curve as well as at the bottom. Therefore, they are contrary to the hypothesis that nutrition played a major role in recent Argentine IQ gains.…

  19. Brain Gain am Beispiel Österreich

    Science.gov (United States)

    Aschbacher, Christine; Gejguš, Mirko; Sablik, Jozef

    2016-06-01

    BrainGain is a common trend within the last ten years in Europe and all-over the world. Managers, key players and scientists are allowed to choose wherever they want to work in the world. As there is a lack of qualified individuals for companies and universities, BrainGain has become a necessity, and mostly - the higher educated individuals are moving away according to a better offer elsewhere in the world. Therefore, a lot of expats are moving around with their families. Many times, the lack of integration at the current place, country or city, is the critical success factor for staying or leaving. Furthermore, if the family does not feel happy in the current location, then the manager or scientist will move away or return home and the investment will be lost. Moreover, many students have received a good education in a state university, however afterwards they have not secured a satisfactory job in the country where they have studied, therefore they are moving away to utilise their know-how. Measures to retain the know-how include a common placement and a welcome-culture in the country, and also exchanges on an international level.

  20. Risk Insights Gained from Fire Incidents

    International Nuclear Information System (INIS)

    Kazarians, Mardy; Nowlen, Steven P.

    1999-01-01

    There now exist close to 20 years of history in the application of Probabilistic Risk Assessment (PRA) for the analysis of fire risk at nuclear power plants. The current methods are based on various assumptions regarding fire phenomena, the impact of fire on equipment and operator response, and the overall progression of a fire event from initiation through final resolution. Over this same time period, a number of significant fire incidents have occurred at nuclear power plants around the world. Insights gained from US experience have been used in US studies as the statistical basis for establishing fire initiation frequencies both as a function of the plant area and the initiating fire source.To a lesser extent, the fire experience has also been used to assess the general severity and duration of fires. However, aside from these statistical analyses, the incidents have rarely been scrutinized in detail to verify the underlying assumptions of fire PRAs. This paper discusses an effort, under which a set of fire incidents are being reviewed in order to gain insights directly relevant to the methods, data, and assumptions that form the basis for current fire PRAs. The paper focuses on the objectives of the effort, the specific fire events being reviews methodology, and anticipated follow-on activities

  1. Spacecraft Angular Rates Estimation with Gyrowheel Based on Extended High Gain Observer

    Directory of Open Access Journals (Sweden)

    Xiaokun Liu

    2016-04-01

    Full Text Available A gyrowheel (GW is a kind of electronic electric-mechanical servo system, which can be applied to a spacecraft attitude control system (ACS as both an actuator and a sensor simultaneously. In order to solve the problem of two-dimensional spacecraft angular rate sensing as a GW outputting three-dimensional control torque, this paper proposed a method of an extended high gain observer (EHGO with the derived GW mathematical model to implement the spacecraft angular rate estimation when the GW rotor is working at large angles. For this purpose, the GW dynamic equation is firstly derived with the second kind Lagrange method, and the relationship between the measurable and unmeasurable variables is built. Then, the EHGO is designed to estimate and calculate spacecraft angular rates with the GW, and the stability of the designed EHGO is proven by the Lyapunov function. Moreover, considering the engineering application, the effect of measurement noise in the tilt angle sensors on the estimation accuracy of the EHGO is analyzed. Finally, the numerical simulation is performed to illustrate the validity of the method proposed in this paper.

  2. An output amplitude configurable wideband automatic gain control with high gain step accuracy

    International Nuclear Information System (INIS)

    He Xiaofeng; Ye Tianchun; Mo Taishan; Ma Chengyan

    2012-01-01

    An output amplitude configurable wideband automatic gain control (AGC) with high gain step accuracy for the GNSS receiver is presented. The amplitude of an AGC is configurable in order to cooperate with baseband chips to achieve interference suppression and be compatible with different full range ADCs. And what's more, the gain-boosting technology is introduced and the circuit is improved to increase the step accuracy. A zero, which is composed by the source feedback resistance and the source capacity, is introduced to compensate for the pole. The AGC is fabricated in a 0.18 μm CMOS process. The AGC shows a 62 dB gain control range by 1 dB each step with a gain error of less than 0.2 dB. The AGC provides 3 dB bandwidth larger than 80 MHz and the overall power consumption is less than 1.8 mA, and the die area is 800 × 300 μm 2 . (semiconductor integrated circuits)

  3. Correlates of pregnant women's gestational weight gain knowledge.

    Science.gov (United States)

    Willcox, Jane Catherine; Ball, Kylie; Campbell, Karen Jane; Crawford, David Andrew; Wilkinson, Shelley Ann

    2017-06-01

    to investigate correlates of pregnant women's gestational weight gain (GWG) knowledge commensurate with GWG guidelines. cross sectional quantitative study. an Australian tertiary level maternity hospital. pregnant women (n=1032) following their first antenatal visit. survey to assess GWG knowledge and a range of potential correlates of knowledge including socio-economic characteristics, pregnancy characteristics (parity, gestation, pre-pregnancy BMI) and GWG information procurement and GWG attitudinal variables. participants (n=366; 35.4% response) averaged 32.5 years of age with 33% speaking a language other than English. One third of women reported GWG knowledge consistent with guidelines. Women overweight prior to pregnancy were less likely to underestimate appropriate GWG (RRR 0.23, 95% CI=0.09-0.59). Conversely, women in the overweight (RRR 8.80, 95% CI=4.02-19.25) and obese (RRR 19.62, 95% CI=8.03-48.00) categories were more likely to overestimate GWG recommendations, while tertiary educated women were less likely to overestimate GWG (RRR 0.28, 95% CI=0.10-0.79). No associations were found between GWG knowledge and pregnancy, GWG information source or attitudinal variables. the findings highlight women's lack of GWG knowledge and the role of pre-pregnancy body mass index and women's education as correlates of GWG knowledge. Women susceptible to poor GWG knowledge should be a priority target for individual and community-based education. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Public attitudes to GM foods. The balancing of risks and gains.

    Science.gov (United States)

    Hudson, John; Caplanova, Anetta; Novak, Marcel

    2015-09-01

    In the paper we study the variables influencing attitudes to the use of two biotechnologies related to gene transfer within apples. Using Eurobarometer 73.1 survey data on biotechnology, science and technology, with 15,650 respondents, we study the extent these attitudes are determined by socio-economic and other variables. We found that attitudes to the risks and gains are determined by socio-economic variables and also by the individual's knowledge, scientific background, their parent's education in science and their religion. Perceptions of naturalness and of environmental impact combined with perceived risks and gains in determining overall approval, proxied by views on whether the technologies should be encouraged, for GMTs. However there are substantial differences in attitudes to transgenesis and cisgenesis. Published by Elsevier Ltd.

  5. Large deviations

    CERN Document Server

    Deuschel, Jean-Dominique; Deuschel, Jean-Dominique

    2001-01-01

    This is the second printing of the book first published in 1988. The first four chapters of the volume are based on lectures given by Stroock at MIT in 1987. They form an introduction to the basic ideas of the theory of large deviations and make a suitable package on which to base a semester-length course for advanced graduate students with a strong background in analysis and some probability theory. A large selection of exercises presents important material and many applications. The last two chapters present various non-uniform results (Chapter 5) and outline the analytic approach that allow

  6. Charge Gain, Voltage Gain, and Node Capacitance of the SAPHIRA Detector Pixel by Pixel

    Science.gov (United States)

    Pastrana, Izabella M.; Hall, Donald N. B.; Baker, Ian M.; Jacobson, Shane M.; Goebel, Sean B.

    2018-01-01

    The University of Hawai`i Institute for Astronomy has partnered with Leonardo (formerly Selex) in the development of HgCdTe linear mode avalanche photodiode (L-APD) SAPHIRA detectors. The SAPHIRA (Selex Avalanche Photodiode High-speed Infra-Red Array) is ideally suited for photon-starved astronomical observations, particularly near infrared (NIR) adaptive optics (AO) wave-front sensing. I have measured the stability, and linearity with current, of a 1.7-um (10% spectral bandpass) infrared light emitting diode (IR LED) used to illuminate the SAPHIRA and have then utilized this source to determine the charge gain (in e-/ADU), voltage gain (in uV/ADU), and node capacitance (in fF) for each pixel of the 320x256@24um SAPHIRA. These have previously only been averages over some sub-array. Determined from the ratio of the temporal averaged signal level to variance under constant 1.7-um LED illumination, I present the charge gain pixel-by-pixel in a 64x64 sub-array at the center of the active area of the SAPHIRA (analyzed separately as four 32x32 sub-arrays) to be about 1.6 e-/ADU (σ=0.5 e-/ADU). Additionally, the standard technique of varying the pixel reset voltage (PRV) in 10 mV increments and recording output frames for the same 64x64 subarray found the voltage gain per pixel to be about 11.7 uV/ADU (σ=0.2 uV/ADU). Finally, node capacitance was found to be approximately 23 fF (σ=6 fF) utilizing the aforementioned charge and voltage gain measurements. I further discuss the linearity measurements of the 1.7-um LED used in the charge gain characterization procedure.

  7. Maximizing Lumen Gain With Directional Atherectomy.

    Science.gov (United States)

    Stanley, Gregory A; Winscott, John G

    2016-08-01

    To describe the use of a low-pressure balloon inflation (LPBI) technique to delineate intraluminal plaque and guide directional atherectomy in order to maximize lumen gain and achieve procedure success. The technique is illustrated in a 77-year-old man with claudication who underwent superficial femoral artery revascularization using a HawkOne directional atherectomy catheter. A standard angioplasty balloon was inflated to 1 to 2 atm during live fluoroscopy to create a 3-dimensional "lumenogram" of the target lesion. Directional atherectomy was performed only where plaque impinged on the balloon at a specific fluoroscopic orientation. The results of the LPBI technique were corroborated with multimodality diagnostic imaging, including digital subtraction angiography, intravascular ultrasound, and intra-arterial pressure measurements. With the LPBI technique, directional atherectomy can routinely achieve <10% residual stenosis, as illustrated in this case, thereby broadly supporting a no-stent approach to lower extremity endovascular revascularization. © The Author(s) 2016.

  8. Rfq With An Increased Energy Gain

    CERN Document Server

    Kapin, Valery

    2004-01-01

    The radio-frequency quadrupole (RFQ) linacs are widely used in the initial part of ion accelerators. For industrial and medical applications, the size of RFQ linac as well as the construction and operation costs are important. Therefore, there is a interest to design a compact RFQ linac. In this paper, RFQ linac is studied with the aim of increasing the energy gain. Parameters of a conventional RFQ linac are usually chosen to ensure beam acceleration and stability, providing the autophasing and strong quadrupole focusing in the longitudinal and transverse directions simultaneously. As results, the accelerating efficiency of RFQ is limited by the transverse defocusing effect, and its value is below of a maximum value, which can be provided by RFQ electrodes. To facilitate these limitations, the well-known idea of alternating phase focusing (APF) is utilized. The APF effects boost transverse focusing, allowing to increase an accelerating efficiency, electrode voltage and decreasing average value of the synchron...

  9. High Gain Antenna Calibration on Three Spacecraft

    Science.gov (United States)

    Hashmall, Joseph A.

    2011-01-01

    This paper describes the alignment calibration of spacecraft High Gain Antennas (HGAs) for three missions. For two of the missions (the Lunar Reconnaissance Orbiter and the Solar Dynamics Observatory) the calibration was performed on orbit. For the third mission (the Global Precipitation Measurement core satellite) ground simulation of the calibration was performed in a calibration feasibility study. These three satellites provide a range of calibration situations-Lunar orbit transmitting to a ground antenna for LRO, geosynchronous orbit transmitting to a ground antenna fer SDO, and low Earth orbit transmitting to TDRS satellites for GPM The calibration results depend strongly on the quality and quantity of calibration data. With insufficient data the calibration Junction may give erroneous solutions. Manual intervention in the calibration allowed reliable parameters to be generated for all three missions.

  10. Gain-of-function HCN2 variants in genetic epilepsy.

    Science.gov (United States)

    Li, Melody; Maljevic, Snezana; Phillips, A Marie; Petrovski, Slave; Hildebrand, Michael S; Burgess, Rosemary; Mount, Therese; Zara, Federico; Striano, Pasquale; Schubert, Julian; Thiele, Holger; Nürnberg, Peter; Wong, Michael; Weisenberg, Judith L; Thio, Liu Lin; Lerche, Holger; Scheffer, Ingrid E; Berkovic, Samuel F; Petrou, Steven; Reid, Christopher A

    2018-02-01

    Genetic generalized epilepsy (GGE) is a common epilepsy syndrome that encompasses seizure disorders characterized by spike-and-wave discharges (SWDs). Pacemaker hyperpolarization-activated cyclic nucleotide-gated channels (HCN) are considered integral to SWD genesis, making them an ideal gene candidate for GGE. We identified HCN2 missense variants from a large cohort of 585 GGE patients, recruited by the Epilepsy Phenome-Genome Project (EPGP), and performed functional analysis using two-electrode voltage clamp recordings from Xenopus oocytes. The p.S632W variant was identified in a patient with idiopathic photosensitive occipital epilepsy and segregated in the family. This variant was also independently identified in an unrelated patient with childhood absence seizures from a European cohort of 238 familial GGE cases. The p.V246M variant was identified in a patient with photo-sensitive GGE and his father diagnosed with juvenile myoclonic epilepsy. Functional studies revealed that both p.S632W and p.V246M had an identical functional impact including a depolarizing shift in the voltage dependence of activation that is consistent with a gain-of-function. In contrast, no biophysical changes resulted from the introduction of common population variants, p.E280K and p.A705T, and the p.R756C variant from EPGP that did not segregate with disease. Our data suggest that HCN2 variants can confer susceptibility to GGE via a gain-of-function mechanism. © 2017 Wiley Periodicals, Inc.

  11. Habitual active transport, TV viewing and weight gain: a four year follow-up study.

    Science.gov (United States)

    Ding, Ding; Sugiyama, Takemi; Owen, Neville

    2012-01-01

    To examine the associations of TV viewing time and domain-specific physical activity with weight change; to determine whether domain-specific physical activity moderates the potential association of TV viewing time with weight change. We used four-year longitudinal data (baseline: 2003-2004, follow-up: 2007-2008) on 969 adults from selected neighborhoods in Adelaide, Australia (Age: 48.6 ± 10.6 years, 61% females). Mixed models examined four-year weight change as the dependent variable, with TV viewing time, habitual transport and past week domain-specific physical activity at baseline as independent variables. On average, participants gained 1.6 kg over four years. TV viewing time at baseline was positively associated with weight gain at follow-up. Each additional hour of TV viewing was associated with 0.24-0.27 kg of extra weight gain. This relationship was not moderated by recent recall of transport, leisure-time, and occupational physical activity, but was moderated by habitual transport: an additional hour of TV viewing time at baseline was significantly associated with an extra weight gain of 0.65 kg at follow-up among those who were inactive in everyday transport; TV time was not significantly associated with weight change among those who were regularly active in transport. Habitual active transport may protect adults against risk of weight gain associated with prolonged TV viewing time. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. NEGOTIATING PECUNIARY GAINS AND ENVIRONMENT PROTECTION

    Directory of Open Access Journals (Sweden)

    Dacinia Crina PETRESCU

    2016-12-01

    Full Text Available The initiation and development of the negotiation process is the result of the interaction between stimulating and hindering factors, among which there are perceived winning chances and perceived risk of projecting a negative image of himself/ herself. The objectives of the research were to observe the strength of people’s perception regarding these two variables and if they were influenced by the negotiation objective: a pecuniary one vs. an environmental one (both involving self-advocacy: aiming at personal benefits. From the point of view of the analyzed variables, people are good negotiators – they have high trust in winning chances and low fear of negative image, but they do not hold strong environmental concerns. The perceived winning chances were significantly higher (p0.05.

  13. Mechanism of blood pressure and R-R variability: insights from ganglion blockade in humans

    Science.gov (United States)

    Zhang, Rong; Iwasaki, Kenichi; Zuckerman, Julie H.; Behbehani, Khosrow; Crandall, Craig G.; Levine, Benjamin D.; Blomqvist, C. G. (Principal Investigator)

    2002-01-01

    Spontaneous blood pressure (BP) and R-R variability are used frequently as 'windows' into cardiovascular control mechanisms. However, the origin of these rhythmic fluctuations is not completely understood. In this study, with ganglion blockade, we evaluated the role of autonomic neural activity versus other 'non-neural' factors in the origin of BP and R-R variability in humans. Beat-to-beat BP, R-R interval and respiratory excursions were recorded in ten healthy subjects (aged 30 +/- 6 years) before and after ganglion blockade with trimethaphan. The spectral power of these variables was calculated in the very low (0.0078-0.05 Hz), low (0.05-0.15 Hz) and high (0.15-0.35 Hz) frequency ranges. The relationship between systolic BP and R-R variability was examined by cross-spectral analysis. After blockade, R-R variability was virtually abolished at all frequencies; however, respiration and high frequency BP variability remained unchanged. Very low and low frequency BP variability was reduced substantially by 84 and 69 %, respectively, but still persisted. Transfer function gain between systolic BP and R-R interval variability decreased by 92 and 88 % at low and high frequencies, respectively, while the phase changed from negative to positive values at the high frequencies. These data suggest that under supine resting conditions with spontaneous breathing: (1) R-R variability at all measured frequencies is predominantly controlled by autonomic neural activity; (2) BP variability at high frequencies (> 0.15 Hz) is mediated largely, if not exclusively, by mechanical effects of respiration on intrathoracic pressure and/or cardiac filling; (3) BP variability at very low and low frequencies (rhythmicity; and (4) the dynamic relationship between BP and R-R variability as quantified by transfer function analysis is determined predominantly by autonomic neural activity rather than other, non-neural factors.

  14. Maximal intended velocity training induces greater gains in bench press performance than deliberately slower half-velocity training.

    Science.gov (United States)

    González-Badillo, Juan José; Rodríguez-Rosell, David; Sánchez-Medina, Luis; Gorostiaga, Esteban M; Pareja-Blanco, Fernando

    2014-01-01

    The purpose of this study was to compare the effect on strength gains of two isoinertial resistance training (RT) programmes that only differed in actual concentric velocity: maximal (MaxV) vs. half-maximal (HalfV) velocity. Twenty participants were assigned to a MaxV (n = 9) or HalfV (n = 11) group and trained 3 times per week during 6 weeks using the bench press (BP). Repetition velocity was controlled using a linear velocity transducer. A complementary study (n = 10) aimed to analyse whether the acute metabolic (blood lactate and ammonia) and mechanical response (velocity loss) was different between the MaxV and HalfV protocols used. Both groups improved strength performance from pre- to post-training, but MaxV resulted in significantly greater gains than HalfV in all variables analysed: one-repetition maximum (1RM) strength (18.2 vs. 9.7%), velocity developed against all (20.8 vs. 10.0%), light (11.5 vs. 4.5%) and heavy (36.2 vs. 17.3%) loads common to pre- and post-tests. Light and heavy loads were identified with those moved faster or slower than 0.80 m · s(-1) (∼ 60% 1RM in BP). Lactate tended to be significantly higher for MaxV vs. HalfV, with no differences observed for ammonia which was within resting values. Both groups obtained the greatest improvements at the training velocities (≤ 0.80 m · s(-1)). Movement velocity can be considered a fundamental component of RT intensity, since, for a given %1RM, the velocity at which loads are lifted largely determines the resulting training effect. BP strength gains can be maximised when repetitions are performed at maximal intended velocity.

  15. Operational experience gained from the Central Brae subsea field

    International Nuclear Information System (INIS)

    Sapp, S.J.; Gomersall, S.D.

    1994-01-01

    The size of the field discoveries made in the North Sea in recent years has declined dramatically. With the low oil price many small fields are not viable stand alone developments. The North Sea has a large, well developed infrastructure of production facilities and pipelines. With many platforms now operating below optimum production rate, subsea tieback of these small fields utilizing the available processing capacity is the most economically attractive means of development. This paper presents a history of such a field development. The Central Brae field is located within the Brae complex of fields, 155 miles north east of Aberdeen, and has been developed by means of a subsea facility tied back to the Brae Alpha platform. A great deal of experience has been gained through the field development, not only in subsea operations but also in completion and template design and operating philosophy

  16. Challenges in Gaining Large Scale Carbon Reductions through Wireless Home Automation Systems

    DEFF Research Database (Denmark)

    Larsen, Peter Gorm; Rovsing, Poul Ejnar; Toftegaard, Thomas Skjødeberg

    2010-01-01

    Buildings account for more than a 35 % of the energy consumption in Europe. Therefore a step towards more sustainable lifestile is to use home automation to optimize the energy consumption “automatically”. This paper reports about the usage and some of the remaining challenges of especially...... wireless but also powerline communication in a home automation setting. For many years, home automation has been visible to many, but accessible to only a few, because of inadequate integration of systems. A vast number of both standard and proprietary communication protocols are used, and systems...... are often difficult to install and configure so professional assistance is needed. In this paper we report about our experience in constructing an open universal home automation framework enabling interoperability of multiple communication protocols. The framework can easily be expanded in order to support...

  17. Response rates and selection problems, with emphasis on mental health variables and DNA sampling, in large population-based, cross-sectional and longitudinal studies of adolescents in Norway

    Directory of Open Access Journals (Sweden)

    Lien Lars

    2010-10-01

    Full Text Available Abstract Background Selection bias is a threat to the internal validity of epidemiological studies. In light of a growing number of studies which aim to provide DNA, as well as a considerable number of invitees who declined to participate, we discuss response rates, predictors of lost to follow-up and failure to provide DNA, and the presence of possible selection bias, based on five samples of adolescents. Methods We included nearly 7,000 adolescents from two longitudinal studies of 18/19 year olds with two corresponding cross-sectional baseline studies at age 15/16 (10th graders, and one cross-sectional study of 13th graders (18/19 years old. DNA was sampled from the cheek mucosa of 18/19 year olds. Predictors of lost to follow-up and failure to provide DNA were studied by Poisson regression. Selection bias in the follow-up at age 18/19 was estimated through investigation of prevalence ratios (PRs between selected exposures (physical activity, smoking and outcome variables (general health, mental distress, externalizing problems measured at baseline. Results Out of 5,750 who participated at age 15/16, we lost 42% at follow-up at age 18/19. The percentage of participants who gave their consent to DNA provision was as high as the percentage that consented to a linkage of data with other health registers and surveys, approximately 90%. Significant predictors of lost to follow-up and failure to provide DNA samples in the present genetic epidemiological study were: male gender; non-western ethnicity; postal survey compared with school-based; low educational plans; low education and income of father; low perceived family economy; unmarried parents; poor self-reported health; externalized symptoms and smoking, with some differences in subgroups of ethnicity and gender. The association measures (PRs were quite similar among participants and all invitees, with some minor discrepancies in subgroups of non-western boys and girls. Conclusions Lost to

  18. Response rates and selection problems, with emphasis on mental health variables and DNA sampling, in large population-based, cross-sectional and longitudinal studies of adolescents in Norway.

    Science.gov (United States)

    Bjertness, Espen; Sagatun, Ase; Green, Kristian; Lien, Lars; Søgaard, Anne Johanne; Selmer, Randi

    2010-10-12

    Selection bias is a threat to the internal validity of epidemiological studies. In light of a growing number of studies which aim to provide DNA, as well as a considerable number of invitees who declined to participate, we discuss response rates, predictors of lost to follow-up and failure to provide DNA, and the presence of possible selection bias, based on five samples of adolescents. We included nearly 7,000 adolescents from two longitudinal studies of 18/19 year olds with two corresponding cross-sectional baseline studies at age 15/16 (10th graders), and one cross-sectional study of 13th graders (18/19 years old). DNA was sampled from the cheek mucosa of 18/19 year olds. Predictors of lost to follow-up and failure to provide DNA were studied by Poisson regression. Selection bias in the follow-up at age 18/19 was estimated through investigation of prevalence ratios (PRs) between selected exposures (physical activity, smoking) and outcome variables (general health, mental distress, externalizing problems) measured at baseline. Out of 5,750 who participated at age 15/16, we lost 42% at follow-up at age 18/19. The percentage of participants who gave their consent to DNA provision was as high as the percentage that consented to a linkage of data with other health registers and surveys, approximately 90%. Significant predictors of lost to follow-up and failure to provide DNA samples in the present genetic epidemiological study were: male gender; non-western ethnicity; postal survey compared with school-based; low educational plans; low education and income of father; low perceived family economy; unmarried parents; poor self-reported health; externalized symptoms and smoking, with some differences in subgroups of ethnicity and gender. The association measures (PRs) were quite similar among participants and all invitees, with some minor discrepancies in subgroups of non-western boys and girls. Lost to follow-up had marginal impact on the estimated prevalence ratios

  19. Unconventional modes in lasers with spatially varying gain and loss

    International Nuclear Information System (INIS)

    Ge Li; Tuereci, H. E.; Chong, Y. D.; Stone, A. D.; Rotter, S.

    2011-01-01

    We discuss a class of lasing modes created by a spatially inhomogeneous gain profile. These lasing modes are ''extra modes,'' in addition to, and very different from, conventional lasing modes, which arise from the passive cavity resonances. These new modes do not have high intensity across the entire gain region, but instead are localized at the gain boundary and throughout the gain-free region. They are surface modes, originating from the transmission resonances of the gain-free region. Using an S-matrix description we connect these surface modes to the lasing modes in PT-symmetric (balanced gain-loss) cavities.

  20. History of Smoking and Postcessation Weight Gain among Weight Loss Surgery Candidates

    Science.gov (United States)

    Levine, Michele D.; Kalarchian, Melissa A.; Courcoulas, Anita P.; Wisinski, Meghan S.C.; Marcus, Marsha D.

    2007-01-01

    Smoking cessation often results in weight gain. Although smoking cessation frequently is recommended to patients presenting for weight loss surgery (WLS), the relationship between smoking cessation and weight gain among WLS candidates is poorly understood. Thus, we sought to document the history and prevalence of smoking and smoking-related weight gain among WLS candidates. Subjects (N = 67) presenting for bariatric surgery provided demographic information, were interviewed about smoking, and weighed and measured prior to operation. Sixty-seven percent of patients reported a lifetime history of smoking, and 26.9% were current smokers. Among lifetime smokers who had attempted to quit, the average maximum amount of weight gained following smoking cessation was 28.1 pounds, but there was wide variability in postcessation weight gain. These data suggest that smoking among candidates for bariatric surgery is prevalent, and that previous cessation attempts were associated with considerable weight gain. Because patients often receive recommendations to quit smoking and lose weight prior to surgery, additional information on the impact of presurgical smoking cessation on long-tem weight control in this population is needed. PMID:17408868

  1. Association between gestational weight gain and perinatal outcomes in women with chronic hypertension.

    Science.gov (United States)

    Yee, Lynn M; Caughey, Aaron B; Cheng, Yvonne W

    2017-09-01

    Gestational weight gain above or below the 2009 National Academy of Medicine guidelines has been associated with adverse maternal and neonatal outcomes. Although it has been well established that excess gestational weight gain is associated with the development of gestational hypertension and preeclampsia, the relationship between gestational weight gain and adverse perinatal outcomes among women with pregestational (chronic) hypertension is less clear. The objective of this study was to examine the relationship between gestational weight gain above and below National Academy of Medicine guidelines and perinatal outcomes in a large, population-based cohort of women with chronic hypertension. This is a population-based retrospective cohort study of women with chronic hypertension who had term, singleton, vertex births in the United States from 2012 through 2014. Prepregnancy body mass index was calculated using self-reported prepregnancy weight and height. Women were categorized into 4 groups based on gestational weight gain and prepregnancy body mass index: (1) weight gain less than, (2) weight gain within, (3) weight gain 1-19 lb in excess of, and (4) weight gain ≥20 lb in excess of the National Academy of Medicine guidelines. The χ 2 tests and multivariable logistic regression analysis were used for statistical comparisons. Stratified analyses by body mass index category were additionally performed. In this large birth cohort, 101,259 women met criteria for inclusion. Compared to hypertensive women who had gestational weight gain within guidelines, hypertensive women with weight gain ≥20 lb over National Academy of Medicine guidelines were more likely to have eclampsia (adjusted odds ratio, 1.93; 95% confidence interval, 1.54-2.42) and cesarean delivery (adjusted odds ratio, 1.60; 95% confidence interval, 1.50-1.70). Excess weight gain ≥20 lb over National Academy of Medicine guidelines was also associated with increased odds of 5-minute Apgar gain 1-19 lb

  2. Interdelivery weight gain and risk of cesarean delivery following a prior vaginal delivery.

    Science.gov (United States)

    Dude, Annie M; Lane-Cordova, Abbi D; Grobman, William A

    2017-09-01

    Approximately one third of all deliveries in the United States are via cesarean. Previous research indicates weight gain during pregnancy is associated with an increased risk of cesarean delivery. It remains unclear, however, whether and to what degree weight gain between deliveries (ie, interdelivery weight gain) is associated with cesarean delivery in a subsequent pregnancy following a vaginal delivery. The objective of the study was to determine whether interdelivery weight gain is associated with an increased risk of intrapartum cesarean delivery following a vaginal delivery. This was a case-control study of women who had 2 consecutive singleton births of at least 36 weeks' gestation between 2005 and 2016, with a vaginal delivery in the index pregnancy. Women were excluded if they had a contraindication to a trial of labor (eg, fetal malpresentation or placenta previa) in the subsequent pregnancy. Maternal characteristics and delivery outcomes for both pregnancies were abstracted from the medical record. Maternal weight gain between deliveries was measured as the change in body mass index at delivery. Women who underwent a subsequent cesarean delivery were compared with those who had a repeat vaginal delivery using χ 2 statistics for categorical variables and Student t tests or analysis of variance for continuous variables. Multivariable logistic regression was used to determine whether interdelivery weight gain remained independently associated with intrapartum cesarean delivery after adjusting for potential confounders. Of 10,396 women who met eligibility criteria and had complete data, 218 (2.1%) had a cesarean delivery in the subsequent pregnancy. Interdelivery weight gain was significantly associated with cesarean delivery and remained significant in multivariable analysis for women with a body mass index increase of at least 2 kg/m 2 (adjusted odds ratio, 1.53, 95% confidence interval, 1.03-2.27 for a body mass index increase of 2 kg/m 2 to gained 2 kg

  3. Kinetics of strength gain of biocidal cements

    Directory of Open Access Journals (Sweden)

    Rodin Aleksandr Ivanovich

    Full Text Available Biocorrosion becomes the determinative durability factor of buildings and constructions. Damages of construction materials caused by bacteria, filamentous fungi, actinomycetes constitute a serious danger to the constructions of a building or a structure and to the health of people. Biodeteriorations are typical both in old and new constructions. A great quantity of destruction factors of industrial and residential buildings under the influence of microorganisms was established in practice. Providing products and constructions based on concretes fungicidal and bactericidal properties is an important direction of modern construction material science. The most efficient way to solve this task is creation of biocidal cements. The article presents the results of experimental studies of kinetic dependences of strength gain by biocidal cements by physico-mechanical and physico-chemical analysis methods. The identical velocity character of initial hydration of the developed compositions of biocidal cements is set, as well as a more calm behavior of hardening processes at later terms. It has been established that the compositions of biocidal cements modified by sodium sulfate and sodium fluoride possess the greatest strength.

  4. Gaining public acceptance for Temelin NPP

    International Nuclear Information System (INIS)

    Novak, Miroslav

    1995-01-01

    , this gave the CEZ utility the opportunity to communicate efficiently with the public about nuclear energy and Temelin in the way Western European and American utilities do. CEZ became a recognized partner and was in a position to begin gaining (or losing) credit. How to gain public credit ( experience of 1993-1994): by always telling the truth, of course. We resumed discussions with representatives of towns and villages around Temelin, who initially were against the completion of the plant. We began to meet regularly every two months. They asked questions and we answered them. Their attitude changed: they were no more resolutely against but demanded supervision of the construction and securing absolute safety. We have adopted rules that prevent appreciable financial help to be given to the communes before the power plant is put in operation. There was another aspect that had to be confirmed, namely, that the Czech Republic really needs electricity from Temelin and that Temelin is the cheapest option in the new political and economic environment. Public opinion as a whole continued to support nuclear power but the voices of opponents, among whom were important persons such as the prime minister in the first Czech post-revolution government, were gaining in strength. Communities in the surroundings of Temelin formed an association against completion of the plant and began to exert pressure on the government to put a stop to the construction. The public was kept informed about nuclear power, the Information center at the plant was active, but it was vital that the government should support the construction and say its clear and unambiguous 'yes'. The utility on its own could not affect the state of affairs. In March 1993, the Czech government discussed the completion of Temelin and gave its nearly unanimous consent. So, for the first time since 1989, the CEZ utility got into a position which the majority of utilities operating nuclear power plants worldwide enjoys. In

  5. Medical Gains of Chondroitin Sulfate Upon Fucosylation.

    Science.gov (United States)

    Pomin, Vitor H

    2015-01-01

    Chondroitin sulfate (CS) is a glycosaminoglycan (GAG) composed of alternating N-acetyl galactosamine and glucuronic acid units within disaccharide building blocks. CS is a key functional component in proteoglycans of cartilaginous tissues. Owing to its numerous biological roles, CS is widely explored in the pharmaceutical market as nutraceutical ingredient commonly utilized against arthritis, osteoarthrosis, and sometimes osteoporosis. Tissues like shark cartilage and bovine trachea are common sources of CS. Nonetheless, a new CS type has been introduced and investigated in the last few decades in what regards its medical potentials. It is named fucosylated chondroitin sulfate (FucCS). This less common CS type is isolated exclusively from the body wall of sea cucumbers. The presence of fucosyl branching units in the holothurian FucCS gives to this unique GAG, therapeutic properties in various pathophysiological systems which are inexistent in the common CS explored in the market. Examples of these systems are coagulation, thrombosis, hemodialysis, atherosclerosis, cellular growth, angiogenesis, fibrosis, tumor growth, inflammation, viral and protozoan infections, hyperglycemia, diabetes-related pathological events and tissue damage. This report aims at describing the medical benefits gained upon fucosylation of CS. Clinical prospects of these medical benefits are also discussed herein.

  6. Progress toward high-gain laser fusion

    International Nuclear Information System (INIS)

    Storm, E.

    1988-01-01

    A 1985-1986 Review of the US inertial confinement fusion program by the National Academy of Sciences concluded that five more years might be required to obtain enough data to determine the future course of the program. Since then, data from the Nova laser and from the Halite/Centurion program have resolved most of the outstanding problems identified by the NAS review. In particular, we now believe that we can produce a sufficiently uniform target; that we can keep the energy content in hot electrons and high-energy photons low enough (/approximately/1--10% of drive energy, depending on target design) and achieve enough pulse-shaping accuracy (/approximately/10%, with a dynamic range of 100:1) to keep the fuel on a near-Fermi-degenerate adiabat; that we can produce an /approximately/100-Mbar pressure pulse of sufficient uniformity (/approximately/1%), and can we control hydrodynamic instabilities so that the mix of the pusher into the hot spot is low enough to permit marginal ignition. These results are sufficiently encouraging that the US Department of Energy is planning to complete a 10-MJ laboratory microfusion facility to demonstrate high-gain ICF in the laboratory within a decade. 22 refs., 1 fig

  7. Weight gain in healthy pregnant women in relation to pre-pregnancy BMI, diet and physical activity.

    Science.gov (United States)

    Merkx, Astrid; Ausems, Marlein; Budé, Luc; de Vries, Raymond; Nieuwenhuijze, Marianne J

    2015-07-01

    to explore gestational weight gain in healthy women in relation to pre-pregnancy Body Mass Index, diet and physical activity. a cross-sectional survey was conducted among 455 healthy pregnant women of all gestational ages receiving antenatal care from an independent midwife in the Netherlands. Weight gain was assessed using the Institute of Medicine (IOM) guidelines and classified as below, within, or above the guidelines. A multinomial regression analysis was performed with weight gain classifications as the dependent variable (within IOM-guidelines as reference). Independent variables were pre-pregnancy Body Mass Index, diet (broken down into consumption of vegetables, fruit and fish) and physical activity (motivation to engage in physical activity, pre-pregnancy physical activity and decline in physical activity during pregnancy). Covariates were age, gestational age, parity, ethnicity, family income, education, perceived sleep deprivation, satisfaction with pre-pregnancy weight, estimated prepregnancy body mass index, smoking, having a weight gain goal and having received weight gain advice from the midwife. forty-two per cent of the women surveyed gained weight within the guidelines. Fourteen per cent of the women gained weight below the guidelines and 44 per cent gained weight above the guidelines. Weight gain within the guidelines, compared to both above and below the guidelines, was not associated with pre-pregnancy Body Mass Index nor with diet. A decline in physical activity was associated with weight gain above the guidelines (OR 0.54, 95 per cent CI 0.33-0.89). Weight gain below the guidelines was seen more often in women who perceived a greater sleep deprivation (OR 1.20, 95 per cent CI 1.02-1.41). Weight gain above the guidelines was seen less often in Caucasian women in comparison to non-Caucasian women (OR 0.22, 95 per cent CI 0.08-0.56) and with women who did not stop smoking during pregnancy (OR 0.49, 95 per cent CI 0.25-0.95). a decline in

  8. Role of 5-HT2C receptor gene variants in antipsychotic-induced weight gain

    Directory of Open Access Journals (Sweden)

    Brandl EJ

    2011-08-01

    Full Text Available Tessa JM Wallace, Clement C Zai, Eva J Brandl, Daniel J MüllerNeurogenetics Section, Center for Addiction and Mental Health, Department of Psychiatry, University of Toronto, Toronto, ON, CanadaAbstract: Antipsychotic-induced weight gain is a serious side effect of antipsychotic medication that can lead to increased morbidity, mortality, and non-compliance in patients. Numerous single nucleotide polymorphisms have been studied for association with antipsychotic-induced weight gain in an attempt to find genetic predictors of this side effect. An ability to predict this side effect could lead to personalized treatment plans for predisposed individuals, which could significantly decrease the prevalence and severity of weight gain. Variations in the serotonin receptor 2c gene (HTR2C have emerged as promising candidates for prediction of antipsychotic-induced weight gain. Specifically, the well-studied -759C/T promoter polymorphism has been associated with weight gain in diverse populations, although some studies have reported no association. This discrepancy is likely due to heterogeneity in study design with respect to ethnicity, treatment duration, and other variables. Notably, the association between HTR2C and antipsychotic-induced weight gain appears strongest in short-term studies on patients with limited or no previous antipsychotic treatment. Other, less extensively studied promoter polymorphisms (-697C/G, -997G/A, and -1165A/G have also emerged as potential predictors of antipsychotic-induced weight gain. Conversely, the well-studied intronic polymorphism Cys23Ser does not appear to be associated. With further research on both HTR2C and other genetic and environmental predictors of antipsychotic-induced weight gain, a predictive test could one day be created to screen patients and provide preventative or alternative treatment for those who are predisposed to this serious side effect.Keywords: HTR2C, pharmacogenomics, promoter polymorphism

  9. Gain beyond cosmesis: Demonstration of psychosocial and functional gains following successful strabismus surgery using the adult strabismus questionnaire adult strabismus 20

    Directory of Open Access Journals (Sweden)

    Danish Alam

    2014-01-01

    Full Text Available Background: Strabismus adversely affects psychosocial and functional aspects; while its correction impacts positively. Aim: The aim was to evaluate the gains in scores: Overall scores (OASs, psychosocial subscale scores (PSSs and functional subscale scores (FSSs following successful surgical alignment. Settings and Design: We evaluated changed scores in the adult strabismus 20 (AS-20 questionnaire, administered before and after successful surgery. Materials and Methods: Thirty adults horizontal strabismics, were administered the AS-20, at baseline, and at 6-week and 3-month. Group-wise analysis was carried out based on gender, strabismus type (esotropia [ET] or exotropia [XT], back-ground and amblyopia. Statistical Analysis: We used Wilcoxon, and Mann-Whitney U-tests. Significance was set at P ≤ 0.05. Results: At baseline, there were no significant differences within the groups, except that those with amblyopia significantly scored less than nonamblyopes in OAS (median scores: 53.8 vs. 71.3; P = 0.009 and FSS (56.3 vs. 85.3; P = 0.009. OAS, PSS and FSS showed significant gains at 6-week and 3-month (all Wilcoxon P < 0.001. Compared with males, females showed significantly more gain at 3-month (OAS: 37.9 vs. 28.7; P = 0.02, on account of PSS gain (49.6 vs. 37.5; P = 0.01. The ET performed better than XT only on the FSS at 6-week (28.7 vs. 15.0; P = 0.02. Vis-à-vis the nonamblyopes, the amblyopes showed significantly more benefit at 6-week alone (OAS: 18.7 vs. 28.7; P = 0.04, largely due to gains in PSS. Conclusions: Successful strabismus surgery has demonstrated significant gains in psychosocial, functional and overall functions. There is some evidence that gains may be more in females; with a trend to better outcomes in ET and amblyopes up to 6-week.

  10. Design and fabrication of an optimum peripheral region for low gain avalanche detectors

    International Nuclear Information System (INIS)

    Fernández-Martínez, Pablo; Flores, D.; Hidalgo, S.; Greco, V.; Merlos, A.; Pellegrini, G.; Quirion, D.

    2016-01-01

    Low Gain Avalanche Detectors (LGAD) represent a remarkable advance in high energy particle detection, since they provide a moderate increase (gain ~10) of the collected charge, thus leading to a notable improvement of the signal-to-noise ratio, which largely extends the possible application of Silicon detectors beyond their present working field. The optimum detection performance requires a careful implementation of the multiplication junction, in order to obtain the desired gain on the read out signal, but also a proper design of the edge termination and the peripheral region, which prevents the LGAD detectors from premature breakdown and large leakage current. This work deals with the critical technological aspects required to optimize the LGAD structure. The impact of several design strategies for the device periphery is evaluated with the aid of TCAD simulations, and compared with the experimental results obtained from the first LGAD prototypes fabricated at the IMB-CNM clean room. Solutions for the peripheral region improvement are also provided.

  11. Design and fabrication of an optimum peripheral region for low gain avalanche detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Martínez, Pablo; Flores, D., E-mail: david.flores@imb-cnm.csic.es; Hidalgo, S.; Greco, V.; Merlos, A.; Pellegrini, G.; Quirion, D.

    2016-06-11

    Low Gain Avalanche Detectors (LGAD) represent a remarkable advance in high energy particle detection, since they provide a moderate increase (gain ~10) of the collected charge, thus leading to a notable improvement of the signal-to-noise ratio, which largely extends the possible application of Silicon detectors beyond their present working field. The optimum detection performance requires a careful implementation of the multiplication junction, in order to obtain the desired gain on the read out signal, but also a proper design of the edge termination and the peripheral region, which prevents the LGAD detectors from premature breakdown and large leakage current. This work deals with the critical technological aspects required to optimize the LGAD structure. The impact of several design strategies for the device periphery is evaluated with the aid of TCAD simulations, and compared with the experimental results obtained from the first LGAD prototypes fabricated at the IMB-CNM clean room. Solutions for the peripheral region improvement are also provided.

  12. Ricardian Productivity Differences and the Gains from Trade

    OpenAIRE

    Andrei A. Levchenko; Jing Zhang

    2013-01-01

    This paper evaluates the role of sectoral heterogeneity in determining the gains from trade. We first show analytically that in the presence of sectoral Ricardian comparative advantage, a one- sector sufficient statistic formula that uses total trade volumes as a share of total absorption systematically understates the true gains from trade. Greater relative sectoral productivity differences lead to larger disparities between the gains implied by the one-sector formula and the true gains. Usi...

  13. Assessment of learning gains in a flipped biochemistry classroom.

    Science.gov (United States)

    Ojennus, Deanna Dahlke

    2016-01-01

    The flipped classroom has become an increasingly popular pedagogical approach to teaching and learning. In this study, learning gains were assessed in a flipped biochemistry course and compared to gains in a traditional lecture. Although measured learning gains were not significantly different between the two courses, student perception of learning gains did differ and indicates a higher level of satisfaction with the flipped lecture format. © 2015 The International Union of Biochemistry and Molecular Biology.

  14. Antenna Gain Impact on UWB Wind Turbine Blade Deflection Sensing

    DEFF Research Database (Denmark)

    Zhang, Shuai; Franek, Ondrej; Byskov, Claus

    2018-01-01

    Antenna gain impact on UWB wind turbine blade deflection sensing is studied in this paper. Simulations are applied with a 4.5-meter blade tip. The antennas with high gain (HG) and low gain (LG) in free space are simulated inside a blade. It is interesting to find that tip antennas with HG and LG...

  15. Assessment of Learning Gains in a Flipped Biochemistry Classroom

    Science.gov (United States)

    Ojennus, Deanna Dahlke

    2016-01-01

    The flipped classroom has become an increasingly popular pedagogical approach to teaching and learning. In this study, learning gains were assessed in a flipped biochemistry course and compared to gains in a traditional lecture. Although measured learning gains were not significantly different between the two courses, student perception of…

  16. 24 CFR 3280.506 - Heat loss/heat gain.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Heat loss/heat gain. 3280.506... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.506 Heat loss/heat gain. The manufactured home heat loss/heat gain shall be determined by methods outlined in...

  17. 26 CFR 1.1247-3 - Treatment of capital gains.

    Science.gov (United States)

    2010-04-01

    ... portion of the excess capital gains were designated. The amount so includible by the partnership shall be... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Treatment of capital gains. 1.1247-3 Section 1... (CONTINUED) INCOME TAXES Special Rules for Determining Capital Gains and Losses § 1.1247-3 Treatment of...

  18. 26 CFR 1.737-1 - Recognition of precontribution gain.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Recognition of precontribution gain. 1.737-1... gain. (a) Determination of gain—(1) In general. A partner that receives a distribution of property (other than money) must recognize gain under section 737 and this section in an amount equal to the...

  19. 24 CFR 3280.507 - Comfort heat gain.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Comfort heat gain. 3280.507 Section... gain. Information necessary to calculate the home cooling load shall be provided as specified in this part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat loss...

  20. Stimulated Raman gain scattering in thin planar dielectric waveguides

    NARCIS (Netherlands)

    Kanger, Johannes S.; Otto, Cornelis; Greve, Jan

    1995-01-01

    The stimulated Raman gain effect in planar dielectric waveguides is analyzed for the study of thin layers. Calculations show high gain factors and predict the possibility of detecting monolayers. Compared with those for methods based on ref lection, the gain can be 4 orders of magnitude higher for a