Sample records for interval exchange transformations

  1. Oligonucleotide gas-phase hydrogen/deuterium exchange with D2S in the collision cell of a quadrupole-Fourier transform ion cyclotron resonance mass spectrometer.

    PubMed

    Mo, Jingjie; Håkansson, Kristina

    2007-10-15

    We have implemented gas-phase hydrogen/deuterium exchange (HDX) experiments in the external collision cell of a hybrid quadrupole-Fourier transform ion cyclotron resonance mass spectrometer. In this configuration, multiply charged oligonucleotide anions undergo significant exchange with D(2)S at reaction intervals ranging from 0.11 to 60.1 s. For DNA homohexamers, relative exchange rates were dC(6) approximately dA(6) > dG(6) > dT(6), correlating with the gas-phase acidities of nucleobases (C > A > T > G), except for guanine. Our results are consistent with a relay mechanism in which D(2)S interacts with both a backbone phosphate group and a neutral nucleobase through hydrogen bonding. We propose that the faster exchange of polyguanosine compared to polythymidine is due to the larger size of guanine and the orientation of its labile hydrogens, which may result in gas-phase conformations more favorable for forming complexes with D(2)S. Similar trends were observed for RNA homohexamers, although their HDX rates were faster than for DNA, suggesting they can also exchange via another relay process involving the 2'-hydroxyl group. HDX of DNA duplexes further supports the involvement of nucleobase hydrogens because duplexes exchanged slower than their corresponding single strands, presumably due to the intermolecular hydrogen bonds between nucleobases. This work constitutes the first investigation of the mechanisms of oligonucleotide gas-phase HDX. Our results on duplexes show promise for application of this strategy to the characterization of structured nucleic acids.

  2. Development of cooling system for 66/6.9kV-20MVA REBCO superconducting transformers with Ne turbo-Brayton refrigerator and subcooled liquid nitrogen

    NASA Astrophysics Data System (ADS)

    Iwakuma, M.; Adachi, K.; Yun, K.; Yoshida, K.; Sato, S.; Suzuki, Y.; Umeno, T.; Konno, M.; Hayashi, H.; Eguchi, T.; Izumi, T.; Shiohara, Y.

    2015-12-01

    We developed a turbo-Brayton refrigerator with Ne gas as a working fluid for a 3 ϕ- 66/6.9kV-2MVA superconducting transformer with coated conductors which was bath-cooled with subcooled LN2. The two-stage compressor and expansion turbine had non-contact magnetic bearings for a long maintenance interval. In the future, we intend to directly install a heat exchanger into the Glass-Fiber-Reinforced-Plastics cryostat of a transformer and make a heat exchange between the working fluid gas and subcooled LN2. In this paper we investigate the behaviour of subcooled LN2 in a test cryostat, in which heater coils were arranged side by side with a flat plate finned-tube heat exchanger. Here a He turbo-Brayton refrigerator was used as a substitute for a Ne turbo-Brayton one. The pressure at the surface of LN2 in the cryostat was one atmosphere. Just under the LN2 surface, a stationary layer of LN2 was created over the depth of 20 cm and temperature dropped from 77 K to 65 K with depth while, in the lower level than that, a natural convection flow of LN2 was formed and temperature was almost uniform over 1 m depth. The boundary plane between the stationary layer and the natural convection region was visible.

  3. Large and reversible inverse magnetocaloric effect in Ni48.1Co2.9Mn35.0In14.0 metamagnetic shape memory microwire

    NASA Astrophysics Data System (ADS)

    Qu, Y. H.; Cong, D. Y.; Chen, Z.; Gui, W. Y.; Sun, X. M.; Li, S. H.; Ma, L.; Wang, Y. D.

    2017-11-01

    High-performance magnetocaloric materials should have a large reversible magnetocaloric effect and good heat exchange capability. Here, we developed a Ni48.1Co2.9Mn35.0In14.0 metamagnetic shape memory microwire with a large and reversible inverse magnetocaloric effect. As compared to the bulk counterpart, the microwire shows a better combination of magnetostructural transformation parameters (magnetization difference across transformation ΔM, transformation entropy change ΔStr, thermal hysteresis ΔThys, and transformation interval ΔTint) and thus greatly reduced critical field required for complete and reversible magnetic-field-induced transformation. A strong and reversible metamagnetic transition occurred in the microwire, which facilitates the achievement of large reversible magnetoresponsive effects. Consequently, a large and reversible magnetic-field-induced entropy change ΔSm of 12.8 J kg-1 K-1 under 5 T was achieved in the microwire, which is the highest value reported heretofore in Ni-Mn-based magnetic shape memory wires. Furthermore, since microwires have a high surface/volume ratio, they exhibit very good heat exchange capability. The present Ni48.1Co2.9Mn35.0In14.0 microwire shows great potential for magnetic refrigeration. This study may stimulate further development of high-performance magnetocaloric wires for high-efficiency and environmentally friendly solid-state cooling.

  4. An annual model of SSM/I radiobrightness for dry soil

    NASA Technical Reports Server (NTRS)

    Liou, Yuei-An; England, A. W.

    1992-01-01

    An annual model is presented of the temperature structure within a homogeneous, dry soil halfspace that is subject to both diurnal and annual insolation, radiant heating from the atmosphere, sensible heat exchange with the atmosphere, and radiant cooling. The thermal constitutive properties of the soil are assumed to be constant so that the heat flow equation can be solved analytically. For computational economy, a variable time interval Laplace transform method is developed to predict the temperature.

  5. Probing chemical transformation in picolitre volume aerosol droplets

    NASA Astrophysics Data System (ADS)

    Miloserdov, Anatolij; Day, Calum P. F.; Rosario, Gabriela L.; Horrocks, Benjamin R.; Carruthers, Antonia E.

    2017-08-01

    We have demonstrated chemical transformation in single microscopic-sized aerosol droplets localised in optical tweezers. Droplets in situ are measured during chemical transformation processes of solvent exchange and solute transformation through an ion exchange reaction. Solvent exchange between deionised water and heavy water in aerosol droplets is monitored through observation of the OH and OD Raman stretches. A change in solute chemistry of aerosol is achieved through droplet coalescence events between calcium chloride and sodium carbonate to promote ion exchange. The transformation forming meta-stable and stable states of CaCO3 is observed and analysed using Gaussian peak decomposition to reveal polymorphs.

  6. Variable-temperature Fourier transform near-infrared imaging spectroscopy of the deuterium/hydrogen exchange in liquid D₂O.

    PubMed

    Unger, Miriam; Ozaki, Yukihiro; Siesler, Heinz W

    2014-01-01

    In the present publication, the deuterium/hydrogen (D/H) exchange of liquid D2O exposed to water vapor of the surrounding atmosphere has been studied by variable-temperature Fourier transform near-infrared (FT-NIR) imaging spectroscopy. Apart from the visualization of the exchange process in the time-resolved FT-NIR images, kinetic parameters and the activation energy for this D/H exchange reaction have been derived from the Arrhenius plot of the variable-temperature spectroscopic data.

  7. Benguela upwelling response during intervals of global climate transition

    NASA Astrophysics Data System (ADS)

    Shrivastava, Ankush; Sinha, Devesh; Singh, Ashutosh; Ramesh, Rengaswamy

    2017-04-01

    In the present study sedimentary records from the southeast Atlantic ocean were used for reconstructing the variability of Benguela upwelling system as well as the Interoceanic exchange between Indian and Atlantic Oceans during the critical intervals. Planktic foraminiferal assemblage data revealed diminished upwelling in the Benguela upwelling region during the Pliocene warm interval (3.7-3 Ma) which is in contrast to the model reconstructions by Wang et al., 2015 proposing intensification of upwelling with projected future warming. Gradual intensification of Benguela upwelling was interpreted during the Pliocene - Pleistocene transition (3-2.5 Ma). Enhanced Benguela upwelling during the Northern Hemisphere Glaciation supposed to have played a major role in the drawdown of atmospheric carbon dioxide after Pliocene warmth interval (3.7-3 Ma). Enhanced Benguela upwelling also occurred during Mid- Pleistocene transition (1-0.7 Ma). Reduced interoceanic exchange has been identified between Indian and Atlantic ocean during Northern Hemisphere glaciation (2.5- 2 Ma) and Mid-Pleistocene transition (1- 0.7 Ma). Equatorward migration of subtropical fronts during these two intervals was probably responsible for the reduced interoceanic exchange. Keywords: Pliocene-Pleistocene transition, Mid- Pleistocene transition, Benguela upwelling, Interoceanic exchange

  8. Concerted ligand exchange and the roles of counter anions in the reversible structural switching of crystalline peptide metallo-macrocycles.

    PubMed

    Miyake, Ryosuke; Shionoya, Mitsuhiko

    2014-06-02

    To understand reversible structural switching in crystalline materials, we studied the mechanism of reversible crystal-to-crystal transformation of a tetranuclear Ni(II) macrocycle consisting of artificial β-dipeptides. On the basis of detailed structural analyses and thermodynamic measurements made in a comparison of pseudo-isostructural crystals (NO3 and BF4 salts), we herein discuss how ligand-exchange reactions take place in the crystal due to changes in water content and temperature. Observations of the structural transformation of NO3 salt indicated that a pseudo crystalline phase transformation takes place through concerted ligand-exchange reactions at the four Ni(II) centers of the macrocycle with hydrogen bond switching. A mechanism for this ligand exchange was supported by IR spectroscopy. Thermodynamic measurements suggested that the favorable compensation relationship of the enthalpy changes due to water uptake and structural changes are keys to the reversible structural transformation. On the basis of a comparison with the pseudo-isostructural crystals, it is apparent that the crystal packing structure and the types of counter anions are important factors for facilitating reversible ligand exchange with single crystallinity.

  9. Power-law behaviour evaluation from foreign exchange market data using a wavelet transform method

    NASA Astrophysics Data System (ADS)

    Wei, H. L.; Billings, S. A.

    2009-09-01

    Numerous studies in the literature have shown that the dynamics of many time series including observations in foreign exchange markets exhibit scaling behaviours. A simple new statistical approach, derived from the concept of the continuous wavelet transform correlation function (WTCF), is proposed for the evaluation of power-law properties from observed data. The new method reveals that foreign exchange rates obey power-laws and thus belong to the class of self-similarity processes.

  10. Estimating CO2 gas exchange in mixed age vegetable plant communities grown on soil-like substrates for life support systems

    NASA Astrophysics Data System (ADS)

    Velichko, V. V.; Tikhomirov, A. A.; Ushakova, S. A.

    2018-02-01

    If soil-like substrate (SLS) is to be used in human life support systems with a high degree of mass closure, the rate of its gas exchange as a compartment for mineralization of plant biomass should be understood. The purpose of this study was to compare variations in CO2 gas exchange of vegetable plant communities grown on the soil-like substrate using a number of plant age groups, which determined the so-called conveyor interval. Two experimental plant communities were grown as plant conveyors with different conveyor intervals. The first plant community consisted of conveyors with intervals of 7 days for carrot and beet and 14 days for chufa sedge. The conveyor intervals in the second plant community were 14 days for carrot and beet and 28 days for chufa sedge. This study showed that increasing the number of age groups in the conveyor and, thus, increasing the frequency of adding plant waste to the SLS, decreased the range of variations in CO2 concentration in the "plant-soil-like substrate" system. However, the resultant CO2 gas exchange was shifted towards CO2 release to the atmosphere of the plant community with short conveyor intervals. The duration of the conveyor interval did not significantly affect productivity and mineral composition of plants grown on the SLS.

  11. Bijective transformation circular codes and nucleotide exchanging RNA transcription.

    PubMed

    Michel, Christian J; Seligmann, Hervé

    2014-04-01

    The C(3) self-complementary circular code X identified in genes of prokaryotes and eukaryotes is a set of 20 trinucleotides enabling reading frame retrieval and maintenance, i.e. a framing code (Arquès and Michel, 1996; Michel, 2012, 2013). Some mitochondrial RNAs correspond to DNA sequences when RNA transcription systematically exchanges between nucleotides (Seligmann, 2013a,b). We study here the 23 bijective transformation codes ΠX of X which may code nucleotide exchanging RNA transcription as suggested by this mitochondrial observation. The 23 bijective transformation codes ΠX are C(3) trinucleotide circular codes, seven of them are also self-complementary. Furthermore, several correlations are observed between the Reading Frame Retrieval (RFR) probability of bijective transformation codes ΠX and the different biological properties of ΠX related to their numbers of RNAs in GenBank's EST database, their polymerization rate, their number of amino acids and the chirality of amino acids they code. Results suggest that the circular code X with the functions of reading frame retrieval and maintenance in regular RNA transcription, may also have, through its bijective transformation codes ΠX, the same functions in nucleotide exchanging RNA transcription. Associations with properties such as amino acid chirality suggest that the RFR of X and its bijective transformations molded the origins of the genetic code's machinery. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. A cross-country Exchange Market Pressure (EMP) dataset.

    PubMed

    Desai, Mohit; Patnaik, Ila; Felman, Joshua; Shah, Ajay

    2017-06-01

    The data presented in this article are related to the research article titled - "An exchange market pressure measure for cross country analysis" (Patnaik et al. [1]). In this article, we present the dataset for Exchange Market Pressure values (EMP) for 139 countries along with their conversion factors, ρ (rho). Exchange Market Pressure, expressed in percentage change in exchange rate, measures the change in exchange rate that would have taken place had the central bank not intervened. The conversion factor ρ can interpreted as the change in exchange rate associated with $1 billion of intervention. Estimates of conversion factor ρ allow us to calculate a monthly time series of EMP for 139 countries. Additionally, the dataset contains the 68% confidence interval (high and low values) for the point estimates of ρ 's. Using the standard errors of estimates of ρ 's, we obtain one sigma intervals around mean estimates of EMP values. These values are also reported in the dataset.

  13. 76 FR 60107 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Order Granting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-28

    ... underlying price ($24.50) is $20, the Exchange may list a $22 strike. The proposal also contains certain non... Rule to Simplify the $1 Strike Price Interval Program September 22, 2011. I. Introduction On July 26... amend Interpretation and Policy .01 to Rule 5.5 to simplify the $1 Strike Price Interval Program (the...

  14. 77 FR 65241 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-25

    ... pursuant to the same strike price interval parameters that exist for Weekly options. Thus a related non... non-Weekly options and the availability of more granular strike price intervals. The Exchange notes... harmonization between of strike prices between Weekly and non-Weekly options on the same classes. With regard to...

  15. Buffered coscheduling for parallel programming and enhanced fault tolerance

    DOEpatents

    Petrini, Fabrizio [Los Alamos, NM; Feng, Wu-chun [Los Alamos, NM

    2006-01-31

    A computer implemented method schedules processor jobs on a network of parallel machine processors or distributed system processors. Control information communications generated by each process performed by each processor during a defined time interval is accumulated in buffers, where adjacent time intervals are separated by strobe intervals for a global exchange of control information. A global exchange of the control information communications at the end of each defined time interval is performed during an intervening strobe interval so that each processor is informed by all of the other processors of the number of incoming jobs to be received by each processor in a subsequent time interval. The buffered coscheduling method of this invention also enhances the fault tolerance of a network of parallel machine processors or distributed system processors

  16. On Chaotic Behavior of Temperature Distribution in a Heat Exchanger

    NASA Astrophysics Data System (ADS)

    Bagyalakshmi, Morachan; Gangadharan, Saisundarakrishnan; Ganesh, Madhu

    The objective of this paper is to introduce the notion of fractional derivatives in the energy equations and to study the chaotic nature of the temperature distribution in a heat exchanger with variation of temperature dependent transport properties. The governing fractional partial differential equations are transformed to a set of recurrence relations using fractional differential transform method and solved using inverse transform. The approximate analytical solution obtained by the proposed method has good agreement with the existing results.

  17. Temporal Dynamics of Social Exchange and the Development of Solidarity: "Testing the Waters" versus "Taking a Leap of Faith"

    ERIC Educational Resources Information Center

    Kuwabara, Ko; Sheldon, Oliver

    2012-01-01

    In their concerted efforts to unpack the microprocesses that transform repeated exchanges into an exchange relation, exchange theorists have paid little attention to how actors perceive changes and dynamics in exchanges over time. We help fill this gap by studying how temporal patterns of exchange affect the development of cohesion. Some exchange…

  18. Characterization of minimal sequences associated with self-similar interval exchange maps

    NASA Astrophysics Data System (ADS)

    Cobo, Milton; Gutiérrez-Romo, Rodolfo; Maass, Alejandro

    2018-04-01

    The construction of affine interval exchange maps (IEMs) with wandering intervals that are semi-conjugate to a given self-similar IEM is strongly related to the existence of the so-called minimal sequences associated with local potentials, which are certain elements of the substitution subshift arising from the given IEM. In this article, under the condition called unique representation property, we characterize such minimal sequences for potentials coming from non-real eigenvalues of the substitution matrix. We also give conditions on the slopes of the affine extensions of a self-similar IEM that determine whether it exhibits a wandering interval or not.

  19. Implied adjusted volatility functions: Empirical evidence from Australian index option market

    NASA Astrophysics Data System (ADS)

    Harun, Hanani Farhah; Hafizah, Mimi

    2015-02-01

    This study aims to investigate the implied adjusted volatility functions using the different Leland option pricing models and to assess whether the use of the specified implied adjusted volatility function can lead to an improvement in option valuation accuracy. The implied adjusted volatility is investigated in the context of Standard and Poor/Australian Stock Exchange (S&P/ASX) 200 index options over the course of 2001-2010, which covers the global financial crisis in the mid-2007 until the end of 2008. Both in- and out-of-sample resulted in approximately similar pricing error along the different Leland models. Results indicate that symmetric and asymmetric models of both moneyness ratio and logarithmic transformation of moneyness provide the overall best result in both during and post-crisis periods. We find that in the different period of interval (pre-, during and post-crisis) is subject to a different implied adjusted volatility function which best explains the index options. Hence, it is tremendously important to identify the intervals beforehand in investigating the implied adjusted volatility function.

  20. Multivariable nonlinear analysis of foreign exchange rates

    NASA Astrophysics Data System (ADS)

    Suzuki, Tomoya; Ikeguchi, Tohru; Suzuki, Masuo

    2003-05-01

    We analyze the multivariable time series of foreign exchange rates. These are price movements that have often been analyzed, and dealing time intervals and spreads between bid and ask prices. Considering dealing time intervals as event timing such as neurons’ firings, we use raster plots (RPs) and peri-stimulus time histograms (PSTHs) which are popular methods in the field of neurophysiology. Introducing special processings to obtaining RPs and PSTHs time histograms for analyzing exchange rates time series, we discover that there exists dynamical interaction among three variables. We also find that adopting multivariables leads to improvements of prediction accuracy.

  1. Severe neonatal hyperbilirubinaemia is frequently associated with long hospitalisation for emergency care in Nigeria.

    PubMed

    Olusanya, Bolajoko O; Mabogunje, Cecilia A; Imam, Zainab O; Emokpae, Abieyuwa A

    2017-12-01

    This study investigated the frequency and predictors of a long hospital stay (LHS) for severe neonatal hyperbilirubinaemia in Nigeria. Length of stay (LOS) for severe hyperbilirubinaemia was examined among neonates consecutively admitted to the emergency department of a children's hospital in Lagos from January 2013 to December 2014. The median LOS was used as the cut-off for LHS. Multivariate logistic regression determined the independent predictors of LHS based on demographic and clinical factors significantly associated with the log-transformed LOS in the bivariate analyses. We enrolled 622 hyperbilirubinaemic infants with a median age of four days (interquartile range 2-6 days) and 276 (44.4%) had LHS based on the median LOS of five days. Regardless of their birth place, infants were significantly more likely to have LHS if they were admitted in the first two days of life (p = 0.008) - especially with birth asphyxia - or had acute bilirubin encephalopathy (p = 0.001) and required one (p = 0.020) or repeat (p = 0.022) exchange transfusions. Infants who required repeat exchange transfusions had the highest odds for LHS (odds ratio 4.98, 95% confidence interval 1.26-19.76). Severe hyperbilirubinaemia was frequently associated with long hospitalisation in Nigeria, especially if neonates had birth asphyxia or required exchange transfusions. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  2. Troubling Gifts of Care: Vulnerable Persons and Threatening Exchanges in Chicago’s Home Care Industry

    PubMed Central

    Buch, Elana

    2015-01-01

    By tracing the transformations of troubling exchanges in paid home care, this article examines how differently positioned individuals strive to build caring relations within potentially restrictive regimes of care. In paid home care in Chicago, older adults and their workers regularly participate in exchanges of money, time, and material goods. These gifts play a crucial role in building good care relationships that sustain participants’ moral personhood. Amid widespread concern about vulnerable elders, home care agencies compete in a crowded marketplace by prohibiting these exchanges, even as they depend on them to strengthen relationships. Supervisors thus exercise discretion, sometimes reclassifying gift exchanges as punishable thefts. In this context, the commodification of care did not lead to the actual elimination of gift relations, but rather transformed gift relations into a suspicious and troublesome source of value. PMID:25331658

  3. Malignant transformation of Taiwanese patients with oral leukoplakia: A nationwide population-based retrospective cohort study.

    PubMed

    Wang, Tung-Yuan; Chiu, Yu-Wei; Chen, Yi-Tzu; Wang, Yu-Hsun; Yu, Hui-Chieh; Yu, Chuan-Hang; Chang, Yu-Chao

    2018-05-01

    Oral leukoplakia (OL) is one of the clinically diagnosed oral potentially malignant disorders (OPMDs) with an increased risk of oral cancer development. In this study, we investigated the malignant transformation of OL in Taiwanese population. A retrospective cohort study was analyzed from Taiwan's National Health Insurance Research Database. A comparison cohort was randomly frequency-matched with the OL cohort according to age, sex, and index year. Oral submucous fibrosis (OSF) and oral lichen planus (OLP) were further stratified to evaluate the possible synergistic effects for OL-associated malignant transformation. In this cohort, 102 (5.374%) of 1898 OL patients were observed to transform into oral cancer. The malignant transformation rate was 26.40-fold in the OL cohort than in the comparison cohort after adjustment (95% confidence intervals 18.46-37.77). To further stratify with OSF and OLP, OL with OSF (58.38; 95% confidence intervals 34.61-98.50) and OL with OLP (36.88; 95% confidence intervals 8.90-152.78) had higher risk of malignant transformation rate than OL alone (27.01; 95% confidence intervals 18.91-38.59). The Kaplan-Meier plot revealed the free of malignant transformation rate was significant over the 13 years follow-up period (log-rank test, p < 0.001). OL patients exhibited a significantly higher risk of malignant transformation than those without OL. In addition, both OSF and OLP could enhance malignant transformation in patients with OL. However, further studies are required to identify the histopathological and clinical parameters in the pathogenesis of malignant transformation among OPMDs. Copyright © 2018. Published by Elsevier B.V.

  4. Troubling gifts of care: vulnerable persons and threatening exchanges in Chicago's home care industry.

    PubMed

    Buch, Elana D

    2014-12-01

    By tracing the transformations of troubling exchanges in paid home care, this article examines how differently positioned individuals strive to build caring relations within potentially restrictive regimes of care. In paid home care in Chicago, older adults and their workers regularly participate in exchanges of money, time, and material goods. These gifts play a crucial role in building good care relationships that sustain participants' moral personhood. Amid widespread concern about vulnerable elders, home care agencies compete in a crowded marketplace by prohibiting these exchanges, even as they depend on them to strengthen relationships. Supervisors thus exercise discretion, sometimes reclassifying gift exchanges as punishable thefts. In this context, the commodification of care did not lead to the actual elimination of gift relations, but rather transformed gift relations into a suspicious and troublesome source of value. © 2014 by the American Anthropological Association.

  5. Transformational Leadership and Organizational Citizenship Behavior: A Meta-Analytic Test of Underlying Mechanisms.

    PubMed

    Nohe, Christoph; Hertel, Guido

    2017-01-01

    Based on social exchange theory, we examined and contrasted attitudinal mediators (affective organizational commitment, job satisfaction) and relational mediators (trust in leader, leader-member exchange; LMX) of the positive relationship between transformational leadership and organizational citizenship behavior (OCB). Hypotheses were tested using meta-analytic path models with correlations from published meta-analyses (761 samples with 227,419 individuals overall). When testing single-mediator models, results supported our expectations that each of the mediators explained the relationship between transformational leadership and OCB. When testing a multi-mediator model, LMX was the strongest mediator. When testing a model with a latent attitudinal mechanism and a latent relational mechanism, the relational mechanism was the stronger mediator of the relationship between transformational leadership and OCB. Our findings help to better understand the underlying mechanisms of the relationship between transformational leadership and OCB.

  6. 75 FR 13174 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Order Approving...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ...-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Order Approving Proposed Rule Change To Establish Strike Price Intervals and Trading Hours for Options on Index-Linked Securities March 12, 2010. I. Introduction On January 27, 2010, the Chicago Board Options Exchange, Incorporated (``CBOE...

  7. Spatial and Temporal Scales of Surface Water-Groundwater Interactions

    NASA Astrophysics Data System (ADS)

    Boano, F.

    2016-12-01

    The interfaces between surface water and groundwater (i.e., river and lake sediments) represent hotspots for nutrient transformation in watersheds. This intense biochemical activity stems from the peculiar physicochemical properties of these interface areas. Here, the exchange of water and nutrients between surface and subsurface environments creates an ecotone region that can support the presence of different microbial species responsible for nutrient transformation. Previous studies have elucidated that water exchange between rivers and aquifers is organized in a complex system of nested flow cells. Each cell entails a range of residence timescales spanning multiple order of magnitudes, providing opportunities for different biochemical reactions to occur. Physically-bases models represent useful tools to deal with the wide range of spatial and temporal scales that characterize surface-subsurface water exchange. This contribution will present insights about how hydrodynamic processes control scale organization for surface water - groundwater interactions. The specific focus will be the influence of exchange processes on microbial activity and nutrient transformation, discussing how groundwater flow at watershed scale controls flow conditions and hence constrain microbial reactions at much smaller scales.

  8. Guided Autobiography's Developmental Exchange: What's in It for Me?

    ERIC Educational Resources Information Center

    Thornton, James E.; Collins, John B.; Birren, James E.; Svensson, Cheryl

    2011-01-01

    The developmental exchange is a central feature of social development, interpersonal dynamics, situated learning, and personal transformation. It is the enabling process in Guided Autobiography (GAB) settings that promotes the achievement of personal goals and group accomplishments. Nevertheless, these exchanges are embedded in the GAB structures…

  9. Innovative design method of automobile profile based on Fourier descriptor

    NASA Astrophysics Data System (ADS)

    Gao, Shuyong; Fu, Chaoxing; Xia, Fan; Shen, Wei

    2017-10-01

    Aiming at the innovation of the contours of automobile side, this paper presents an innovative design method of vehicle side profile based on Fourier descriptor. The design flow of this design method is: pre-processing, coordinate extraction, standardization, discrete Fourier transform, simplified Fourier descriptor, exchange descriptor innovation, inverse Fourier transform to get the outline of innovative design. Innovative concepts of the innovative methods of gene exchange among species and the innovative methods of gene exchange among different species are presented, and the contours of the innovative design are obtained separately. A three-dimensional model of a car is obtained by referring to the profile curve which is obtained by exchanging xenogeneic genes. The feasibility of the method proposed in this paper is verified by various aspects.

  10. Confidence intervals for correlations when data are not normal.

    PubMed

    Bishara, Anthony J; Hittner, James B

    2017-02-01

    With nonnormal data, the typical confidence interval of the correlation (Fisher z') may be inaccurate. The literature has been unclear as to which of several alternative methods should be used instead, and how extreme a violation of normality is needed to justify an alternative. Through Monte Carlo simulation, 11 confidence interval methods were compared, including Fisher z', two Spearman rank-order methods, the Box-Cox transformation, rank-based inverse normal (RIN) transformation, and various bootstrap methods. Nonnormality often distorted the Fisher z' confidence interval-for example, leading to a 95 % confidence interval that had actual coverage as low as 68 %. Increasing the sample size sometimes worsened this problem. Inaccurate Fisher z' intervals could be predicted by a sample kurtosis of at least 2, an absolute sample skewness of at least 1, or significant violations of normality hypothesis tests. Only the Spearman rank-order and RIN transformation methods were universally robust to nonnormality. Among the bootstrap methods, an observed imposed bootstrap came closest to accurate coverage, though it often resulted in an overly long interval. The results suggest that sample nonnormality can justify avoidance of the Fisher z' interval in favor of a more robust alternative. R code for the relevant methods is provided in supplementary materials.

  11. Transformational Leadership and Organizational Citizenship Behavior: A Meta-Analytic Test of Underlying Mechanisms

    PubMed Central

    Nohe, Christoph; Hertel, Guido

    2017-01-01

    Based on social exchange theory, we examined and contrasted attitudinal mediators (affective organizational commitment, job satisfaction) and relational mediators (trust in leader, leader-member exchange; LMX) of the positive relationship between transformational leadership and organizational citizenship behavior (OCB). Hypotheses were tested using meta-analytic path models with correlations from published meta-analyses (761 samples with 227,419 individuals overall). When testing single-mediator models, results supported our expectations that each of the mediators explained the relationship between transformational leadership and OCB. When testing a multi-mediator model, LMX was the strongest mediator. When testing a model with a latent attitudinal mechanism and a latent relational mechanism, the relational mechanism was the stronger mediator of the relationship between transformational leadership and OCB. Our findings help to better understand the underlying mechanisms of the relationship between transformational leadership and OCB. PMID:28848478

  12. 77 FR 54629 - Self-Regulatory Organizations; International Securities Exchange, LLC; Order Granting Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-05

    .... Introduction On May 21, 2012, the International Securities Exchange, LLC (``ISE'' or ``Exchange'') filed with... its Short Term Option Series Program (``STOS Program'') to permit, during the expiration week of an... open for trading Short Term Option Series at $0.50 strike price intervals for option classes that trade...

  13. 78 FR 62771 - Self-Regulatory Organizations; BOX Options Exchange LLC; Notice of Filing and Immediate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ... The Exchange proposes to amend interpretive material to Rule 5050 (Series of Options Contracts Open... Proposed Rule Change 1. Purpose The Exchange proposes to amend IM-5050-6 to Rule 5050 (Series of Options... the strike price interval setting parameters for their Short Term Option Series (``STOS'') Programs...

  14. Forging Colloidal Nanostructures via Cation Exchange Reactions

    PubMed Central

    2016-01-01

    Among the various postsynthesis treatments of colloidal nanocrystals that have been developed to date, transformations by cation exchange have recently emerged as an extremely versatile tool that has given access to a wide variety of materials and nanostructures. One notable example in this direction is represented by partial cation exchange, by which preformed nanocrystals can be either transformed to alloy nanocrystals or to various types of nanoheterostructures possessing core/shell, segmented, or striped architectures. In this review, we provide an up to date overview of the complex colloidal nanostructures that could be prepared so far by cation exchange. At the same time, the review gives an account of the fundamental thermodynamic and kinetic parameters governing these types of reactions, as they are currently understood, and outlines the main open issues and possible future developments in the field. PMID:26891471

  15. Forging Colloidal Nanostructures via Cation Exchange Reactions.

    PubMed

    De Trizio, Luca; Manna, Liberato

    2016-09-28

    Among the various postsynthesis treatments of colloidal nanocrystals that have been developed to date, transformations by cation exchange have recently emerged as an extremely versatile tool that has given access to a wide variety of materials and nanostructures. One notable example in this direction is represented by partial cation exchange, by which preformed nanocrystals can be either transformed to alloy nanocrystals or to various types of nanoheterostructures possessing core/shell, segmented, or striped architectures. In this review, we provide an up to date overview of the complex colloidal nanostructures that could be prepared so far by cation exchange. At the same time, the review gives an account of the fundamental thermodynamic and kinetic parameters governing these types of reactions, as they are currently understood, and outlines the main open issues and possible future developments in the field.

  16. Malignant transformation of oral submucous fibrosis in Taiwan: A nationwide population-based retrospective cohort study.

    PubMed

    Yang, Po-Yu; Chen, Yi-Tzu; Wang, Yu-Hsun; Su, Ni-Yu; Yu, Hui-Chieh; Chang, Yu-Chao

    2017-11-01

    Oral submucous fibrosis (OSF) is one of the well-recognized oral potentially malignant disorders. In this study, we investigated the malignant transformation of OSF in a Taiwanese population. A retrospective cohort study was analyzed from Taiwan's National Health Insurance Research Database. A comparison cohort was randomly frequency-matched with the OSF cohort according to age, sex, and index year. Oral leukoplakia (OL) was further stratified to evaluate for the possible synergistic effects of OSF-associated malignant transformation. In this cohort, 71 (9.13%) of 778 cases of OSF were observed to transform into oral cancer. The malignant transformation rate was 29.26-fold in the OSF cohort than in the comparison cohort after adjustment (95% confidence intervals 20.55-41.67). To further stratify with OL, OSF with OL (52.46%; 95% confidence intervals 34.88-78.91) had higher risk of malignant transformation rate than OSF alone (29.84%; 95% confidence intervals 20.99-42.42). The Kaplan-Meier plot revealed the rate free of malignant transformation was significant over the 13-year follow-up period (log-rank test, P<.001). The mean duration of malignant transformation was 5.1, 2.7, and 2.2 years for non-OSF, OSF alone, and OSF with OL, respectively. Oral submucous fibrosis patients exhibited a significantly higher risk of malignant transformation than those without OSF. OL could enhance malignant transformation in patients with OSF. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. 75 FR 76772 - Bureau of Educational and Cultural Affairs Request for Grant Proposals: Future Leaders Exchange...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-09

    ... Grant Proposals: Future Leaders Exchange Civic Education Workshop Announcement Type: New Grant. Funding... Spring Civic Education Workshop for students participating in the academic year Future Leaders Exchange... they can take home to aid in the transformation of their countries. Public and private non-profit...

  18. Long-Term Percutaneous Nephrostomy Management of Malignant Urinary Obstruction: Estimation of Optimal Exchange Frequency and Estimation of the Financial Impact of Patient Compliance.

    PubMed

    McDevitt, Joseph L; Acosta-Torres, Stefany; Zhang, Ning; Hu, Tianshen; Odu, Ayobami; Wang, Jijia; Xi, Yin; Lamus, Daniel; Miller, David S; Pillai, Anil K

    2017-07-01

    To estimate the least costly routine exchange frequency for percutaneous nephrostomies (PCNs) placed for malignant urinary obstruction, as measured by annual hospital charges, and to estimate the financial impact of patient compliance. Patients with PCNs placed for malignant urinary obstruction were studied from 2011 to 2013. Exchanges were classified as routine or due to 1 of 3 complication types: mechanical (tube dislodgment), obstruction, or infection. Representative cases were identified, and median representative charges were used as inputs for the model. Accelerated failure time and Markov chain Monte Carlo models were used to estimate distribution of exchange types and annual hospital charges under different routine exchange frequency and compliance scenarios. Long-term PCN management was required in 57 patients, with 87 total exchange encounters. Median representative hospital charges for pyelonephritis and obstruction were 11.8 and 9.3 times greater, respectively, than a routine exchange. The projected proportion of routine exchanges increased and the projected proportion of infection-related exchanges decreased when moving from a 90-day exchange with 50% compliance to a 60-day exchange with 75% compliance, and this was associated with a projected reduction in annual charges. Projected cost reductions resulting from increased compliance were generally greater than reductions resulting from changes in exchange frequency. This simulation model suggests that the optimal routine exchange interval for PCN exchange in patients with malignant urinary obstruction is approximately 60 days and that the degree of reduction in charges likely depends more on patient compliance than exact exchange interval. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  19. Are EUR and GBP different words for the same currency?

    NASA Astrophysics Data System (ADS)

    Ivanova, K.; Ausloos, M.

    2002-05-01

    The British Pound (GBP) is not part of the Euro (EUR) monetary system. In order to find out arguments on whether GBP should join the EUR or not correlations are calculated between GBP exchange rates with respect to various currencies: USD, JPY, CHF, DKK, the currencies forming EUR and a reconstructed EUR for the time interval from 1993 till June 30, 2000. The distribution of fluctuations of the exchange rates is Gaussian for the central part of the distribution, but has fat tails for the large size fluctuations. Within the Detrended Fluctuation Analysis (DFA) statistical method the power law behavior describing the root-mean-square deviation from a linear trend of the exchange rate fluctuations is obtained as a function of time for the time interval of interest. The time-dependent exponent evolution of the exchange rate fluctuations is given. Statistical considerations imply that the GBP is already behaving as a true EUR.

  20. Steganography in arrhythmic electrocardiogram signal.

    PubMed

    Edward Jero, S; Ramu, Palaniappan; Ramakrishnan, S

    2015-08-01

    Security and privacy of patient data is a vital requirement during exchange/storage of medical information over communication network. Steganography method hides patient data into a cover signal to prevent unauthenticated accesses during data transfer. This study evaluates the performance of ECG steganography to ensure secured transmission of patient data where an abnormal ECG signal is used as cover signal. The novelty of this work is to hide patient data into two dimensional matrix of an abnormal ECG signal using Discrete Wavelet Transform and Singular Value Decomposition based steganography method. A 2D ECG is constructed according to Tompkins QRS detection algorithm. The missed R peaks are computed using RR interval during 2D conversion. The abnormal ECG signals are obtained from the MIT-BIH arrhythmia database. Metrics such as Peak Signal to Noise Ratio, Percentage Residual Difference, Kullback-Leibler distance and Bit Error Rate are used to evaluate the performance of the proposed approach.

  1. 76 FR 72470 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... Simplify the $1 Strike Price Interval Program November 17, 2011. Pursuant to Section 19(b)(1) of the... by the Exchange. The Exchange has designated the proposed rule change as constituting a non...) of the Rules of the Boston Options Exchange Group, LLC (``BOX'') to simplify the $1 Strike Price...

  2. 75 FR 21689 - Self-Regulatory Organizations; NASDAQ OMX PHLX, Inc.; Order Granting Accelerated Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... To Establish Strike Price Intervals and Trading Hours for Options on Index-Linked Securities April 20... establish strike-price intervals for options on Index-Linked Securities and to establish trading hours for... exchange-traded notes (``ETN'')), Phlx has proposed to establish strike price intervals and trading hours...

  3. Programmed Protection of Foreign DNA from Restriction Allows Pathogenicity Island Exchange during Pneumococcal Transformation

    PubMed Central

    Johnston, Calum; Martin, Bernard; Granadel, Chantal; Polard, Patrice; Claverys, Jean-Pierre

    2013-01-01

    In bacteria, transformation and restriction-modification (R-M) systems play potentially antagonistic roles. While the former, proposed as a form of sexuality, relies on internalized foreign DNA to create genetic diversity, the latter degrade foreign DNA to protect from bacteriophage attack. The human pathogen Streptococcus pneumoniae is transformable and possesses either of two R-M systems, DpnI and DpnII, which respectively restrict methylated or unmethylated double-stranded (ds) DNA. S. pneumoniae DpnII strains possess DpnM, which methylates dsDNA to protect it from DpnII restriction, and a second methylase, DpnA, which is induced during competence for genetic transformation and is unusual in that it methylates single-stranded (ss) DNA. DpnA was tentatively ascribed the role of protecting internalized plasmids from DpnII restriction, but this seems unlikely in light of recent results establishing that pneumococcal transformation was not evolved to favor plasmid exchange. Here we validate an alternative hypothesis, showing that DpnA plays a crucial role in the protection of internalized foreign DNA, enabling exchange of pathogenicity islands and more generally of variable regions between pneumococcal isolates. We show that transformation of a 21.7 kb heterologous region is reduced by more than 4 logs in dpnA mutant cells and provide evidence that the specific induction of dpnA during competence is critical for full protection. We suggest that the integration of a restrictase/ssDNA-methylase couplet into the competence regulon maintains protection from bacteriophage attack whilst simultaneously enabling exchange of pathogenicicy islands. This protective role of DpnA is likely to be of particular importance for pneumococcal virulence by allowing free variation of capsule serotype in DpnII strains via integration of DpnI capsule loci, contributing to the documented escape of pneumococci from capsule-based vaccines. Generally, this finding is the first evidence for a mechanism that actively promotes genetic diversity of S. pneumoniae through programmed protection and incorporation of foreign DNA. PMID:23459610

  4. 75 FR 36138 - Self-Regulatory Organizations; New York Stock Exchange LLC; Notice of Filing of Proposed Rule...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-24

    ... p.m. The 10 minute interval is a legacy time frame related to the Exchange's prior publication of... in the face of a dilemma that is unique to a physical Trading Floor, i.e., how to position resources... efficient operation of the Exchange's market by reducing the frequency of time-consuming Floor broker oral...

  5. Cross-sample entropy of foreign exchange time series

    NASA Astrophysics Data System (ADS)

    Liu, Li-Zhi; Qian, Xi-Yuan; Lu, Heng-Yao

    2010-11-01

    The correlation of foreign exchange rates in currency markets is investigated based on the empirical data of DKK/USD, NOK/USD, CAD/USD, JPY/USD, KRW/USD, SGD/USD, THB/USD and TWD/USD for a period from 1995 to 2002. Cross-SampEn (cross-sample entropy) method is used to compare the returns of every two exchange rate time series to assess their degree of asynchrony. The calculation method of confidence interval of SampEn is extended and applied to cross-SampEn. The cross-SampEn and its confidence interval for every two of the exchange rate time series in periods 1995-1998 (before the Asian currency crisis) and 1999-2002 (after the Asian currency crisis) are calculated. The results show that the cross-SampEn of every two of these exchange rates becomes higher after the Asian currency crisis, indicating a higher asynchrony between the exchange rates. Especially for Singapore, Thailand and Taiwan, the cross-SampEn values after the Asian currency crisis are significantly higher than those before the Asian currency crisis. Comparison with the correlation coefficient shows that cross-SampEn is superior to describe the correlation between time series.

  6. Transforming a state DOT research program.

    DOT National Transportation Integrated Search

    2007-12-01

    The overall theme for the peer exchange was : Transforming a State DOT Research Program. MDOTs : Office of Research & Best Practices is in an exciting : time of transition, aiming to expand its research : coordinating role in the department and to...

  7. INTERIOR OF NORTH ENTRY VESTIBULE, SHOWING TRANSFORMER ROOM BEHIND WIRE ...

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

    INTERIOR OF NORTH ENTRY VESTIBULE, SHOWING TRANSFORMER ROOM BEHIND WIRE MESH, VIEW FACING EAST-SOUTHEAST. - Naval Air Station Barbers Point, Telephone Exchange, Coral Sea Road north of Bismarck Sea Road, Ewa, Honolulu County, HI

  8. 77 FR 6160 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Order Granting Approval of Proposed Rule...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-07

    ... SLV and USO strike price intervals. \\4\\ The Exchange also proposed certain non-substantive changes to... Strike Price Intervals for SLV and USO Options February 1, 2012. I. Introduction On December 7, 2011...-4 thereunder,\\2\\ a proposed rule change regarding strike price intervals for options on iShares[reg...

  9. [Establishing biological reference intervals of alanine transaminase for clinical laboratory stored database].

    PubMed

    Guo, Wei; Song, Binbin; Shen, Junfei; Wu, Jiong; Zhang, Chunyan; Wang, Beili; Pan, Baishen

    2015-08-25

    To establish an indirect reference interval based on the test results of alanine aminotransferase stored in a laboratory information system. All alanine aminotransferase results were included for outpatients and physical examinations that were stored in the laboratory information system of Zhongshan Hospital during 2014. The original data were transformed using a Box-Cox transformation to obtain an approximate normal distribution. Outliers were identified and omitted using the Chauvenet and Tukey methods. The indirect reference intervals were obtained by simultaneously applying nonparametric and Hoffmann methods. The reference change value was selected to determine the statistical significance of the observed differences between the calculated and published reference intervals. The indirect reference intervals for alanine aminotransferase of all groups were 12 to 41 U/L (male, outpatient), 12 to 48 U/L (male, physical examination), 9 to 32 U/L (female, outpatient), and 8 to 35 U/L (female, physical examination), respectively. The absolute differences when compared with the direct results were all smaller than the reference change value of alanine aminotransferase. The Box-Cox transformation combined with the Hoffmann and Tukey methods is a simple and reliable technique that should be promoted and used by clinical laboratories.

  10. Leadership, Innovation Climate, and Attitudes toward Evidence-Based Practice during a Statewide Implementation

    PubMed Central

    Aarons, Gregory A.; Sommerfeld, David H.

    2013-01-01

    Objective Leadership is important in practice change, yet there are few studies addressing this issue in mental health and social services. This study examined the differential roles of transformational (i.e., charismatic) leadership and leader member exchange (i.e., the relationship between a supervisor and their direct service providers) on team innovation climate (i.e., openness to new innovations) and provider attitudes toward adopting evidence-based practice (EBP) during a statewide evidence-based practice implementation (EBPI) of an intervention to reduce child neglect. Methods Participants were 140 case-managers in 30 teams providing home-based services to families in a statewide child-welfare system. Teams were assigned by region to EBPI or services as usual (SAU) conditions. Multiple group path analysis was used to examine associations of transformational leadership and leader member exchange with innovation climate and attitudes toward adoption and use of EBP. Results Transformational leadership predicted higher innovation climate during implementation while leader member exchange predicted higher innovation climate during SAU. Innovation climate was, in turn, associated with more positive attitudes toward EBP for the EBPI group. Conclusions Strategies designed to enhance supervisor transformational leadership have the potential to facilitate implementation efforts by promoting a strong climate for EBPI and positive provider attitudes toward adoption and use of EBP. PMID:22449648

  11. Designing multistep transformations using the Hammett equation: imine exchange on a copper(I) template.

    PubMed

    Schultz, David; Nitschke, Jonathan R

    2006-08-02

    Herein, we quantify how imine exchange may be used to selectively transform one metallo-organic structure into another. A series of imine exchange reactions were studied, involving a set of 4-substituted anilines, their 2-pyridylimines and 1,10-phenanthrolyl-2,9-diimines, as well as the copper complexes of these imine ligands. Electron-rich anilines were found to displace electron-poor anilines in all cases. Linear free energy relationships (LFERs) were discovered connecting the electron-donating or -withdrawing character of the 4-substituent of an aniline, as measured by the Hammett sigma(para) parameter, to that aniline's ability to compete with unsubstituted aniline to form imines. The quality of these LFERs allowed for quantitative predictions: to obtain the desired degree of selectivity in an imine exchange between anilines A and B, the required sigma(para) differential could be predicted using a variant of the Hammett equation, log(K(AB)) = rho(sigma(A) - sigma(B)). We validated this methodology by designing and executing a three-step transformation of a series of copper(I)-containing structures. Each step proceeded in predictably high yield, as calculated from sigma differentials. At each step in the series of transformations, macrocyclic structures could be created or destroyed through the selection of mono- or di-amines as subcomponents. The same methodology could be used to predict the formation of a diverse dynamic library of helicates from a set of four aniline precursors, as well as the collapse of this library into one helicate upon the addition of a fifth aniline.

  12. 76 FR 48935 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-09

    ... the $1 Strike Price Interval Program August 4, 2011. Pursuant to Section 19(b)(1) of the Securities... Proposed Rule Change CBOE proposes to amend its rules in order to simplify the $1 Strike Price Interval... Policy .01 to Rule 5.5 in order to simplify the $1 Strike Price Interval Program (``Program''). In 2003...

  13. Calculation of the confidence intervals for transformation parameters in the registration of medical images

    PubMed Central

    Bansal, Ravi; Staib, Lawrence H.; Laine, Andrew F.; Xu, Dongrong; Liu, Jun; Posecion, Lainie F.; Peterson, Bradley S.

    2010-01-01

    Images from different individuals typically cannot be registered precisely because anatomical features within the images differ across the people imaged and because the current methods for image registration have inherent technological limitations that interfere with perfect registration. Quantifying the inevitable error in image registration is therefore of crucial importance in assessing the effects that image misregistration may have on subsequent analyses in an imaging study. We have developed a mathematical framework for quantifying errors in registration by computing the confidence intervals of the estimated parameters (3 translations, 3 rotations, and 1 global scale) for the similarity transformation. The presence of noise in images and the variability in anatomy across individuals ensures that estimated registration parameters are always random variables. We assume a functional relation among intensities across voxels in the images, and we use the theory of nonlinear, least-squares estimation to show that the parameters are multivariate Gaussian distributed. We then use the covariance matrix of this distribution to compute the confidence intervals of the transformation parameters. These confidence intervals provide a quantitative assessment of the registration error across the images. Because transformation parameters are nonlinearly related to the coordinates of landmark points in the brain, we subsequently show that the coordinates of those landmark points are also multivariate Gaussian distributed. Using these distributions, we then compute the confidence intervals of the coordinates for landmark points in the image. Each of these confidence intervals in turn provides a quantitative assessment of the registration error at a particular landmark point. Because our method is computationally intensive, however, its current implementation is limited to assessing the error of the parameters in the similarity transformation across images. We assessed the performance of our method in computing the error in estimated similarity parameters by applying that method to real world dataset. Our results showed that the size of the confidence intervals computed using our method decreased – i.e. our confidence in the registration of images from different individuals increased – for increasing amounts of blur in the images. Moreover, the size of the confidence intervals increased for increasing amounts of noise, misregistration, and differing anatomy. Thus, our method precisely quantified confidence in the registration of images that contain varying amounts of misregistration and varying anatomy across individuals. PMID:19138877

  14. Anion Exchange in II-VI Semiconducting Nanostructures via Atomic Templating.

    PubMed

    Agarwal, Rahul; Krook, Nadia M; Ren, Ming-Liang; Tan, Liang Z; Liu, Wenjing; Rappe, Andrew M; Agarwal, Ritesh

    2018-03-14

    Controlled chemical transformation of nanostructures is a promising technique to obtain precisely designed novel materials, which are difficult to synthesize otherwise. We report high-temperature vapor-phase anion-exchange reactions to chemically transform II-VI semiconductor nanostructures (100-300 nm length scale) while retaining the single crystallinity, crystal structure, morphology, and even defect distribution of the parent material via atomic templating. The concept of atomic templating is employed to obtain kinetically controlled, thermodynamically metastable structural phases such as zincblende CdSe and CdS from zincblende CdTe upon complete chemical replacement of Te with Se or S. The underlying transformation mechanisms are explained through first-principles density functional theory calculations. Atomic templating is a unique path to independently tune materials' phase and composition at the nanoscale, allowing the synthesis of novel materials.

  15. Children's Environmental Learning, Knowledge, and Interactions under Conditions of Socio-Economic Transformation: The Possibilities of Change.

    ERIC Educational Resources Information Center

    Katz, Cindi R.

    This paper argues that the socio-economic transformation caused by the 1971 Suki Agricultural project in central eastern Sudan has had contradictory effects on children. The Suki Agricultural Project was expected to transform the rural economy from production for consumption to production for exchange and profit. Ten years after the project's…

  16. Effect of Water Chemistry and Hydrodynamics on Nitrogen Transformation Activity and Microbial Community Functional Potential in Hyporheic Zone Sediment Columns

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Yuanyuan; Liu, Chongxuan; Nelson, William C.

    Nitrogen (N) transformation in hyporheic zone (HZ) is an important component in N-cycling in ecosystems. A column study was conducted to investigate N transformation in a HZ sediment with a focus on how characteristic HZ properties including water chemistry, fluid residence time, and dynamic groundwater and surface water exchange affect on N transformation. Metagenomic and quantitative polymerase chain reaction (qPCR) analyses were performed to evaluate the dynamic changes in microbial community structure and its function in response to N transformation. The results indicated that N transformation in the HZ sediment was collectively controlled by microbial community functions including: denitrification, dissimilatorymore » nitrate reduction to ammonium (DNRA), nitrification, and anaerobic ammonium oxidation (anammox). However, the spatial distribution of the microbial community functions and associated biogeochemical reaction rates and products changed quickly in response to experimental perturbation, and was influenced by various factors including water chemistry (dissolved O2 and N species), desorption of sediment associated organic carbon, ion exchange reactions of NH4+, and fluid residence time. The results of this study implied that the microbial community in the HZ would exhibit strong function zonation along N and O gradients, which in turn would control the rates and products of N transformation.« less

  17. A no-key-exchange secure image sharing scheme based on Shamir's three-pass cryptography protocol and the multiple-parameter fractional Fourier transform.

    PubMed

    Lang, Jun

    2012-01-30

    In this paper, we propose a novel secure image sharing scheme based on Shamir's three-pass protocol and the multiple-parameter fractional Fourier transform (MPFRFT), which can safely exchange information with no advance distribution of either secret keys or public keys between users. The image is encrypted directly by the MPFRFT spectrum without the use of phase keys, and information can be shared by transmitting the encrypted image (or message) three times between users. Numerical simulation results are given to verify the performance of the proposed algorithm.

  18. Solving the interval type-2 fuzzy polynomial equation using the ranking method

    NASA Astrophysics Data System (ADS)

    Rahman, Nurhakimah Ab.; Abdullah, Lazim

    2014-07-01

    Polynomial equations with trapezoidal and triangular fuzzy numbers have attracted some interest among researchers in mathematics, engineering and social sciences. There are some methods that have been developed in order to solve these equations. In this study we are interested in introducing the interval type-2 fuzzy polynomial equation and solving it using the ranking method of fuzzy numbers. The ranking method concept was firstly proposed to find real roots of fuzzy polynomial equation. Therefore, the ranking method is applied to find real roots of the interval type-2 fuzzy polynomial equation. We transform the interval type-2 fuzzy polynomial equation to a system of crisp interval type-2 fuzzy polynomial equation. This transformation is performed using the ranking method of fuzzy numbers based on three parameters, namely value, ambiguity and fuzziness. Finally, we illustrate our approach by numerical example.

  19. Where and why hyporheic exchange is important: Inferences from a parsimonious, physically-based river network model

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    Hyporheic exchange has been hypothesized to have basin-scale consequences; however, predictions throughout river networks are limited by available geomorphic and hydrogeologic data as well as models that can analyze and aggregate hyporheic exchange flows across large spatial scales. We developed a parsimonious but physically-based model of hyporheic flow for application in large river basins: Networks with EXchange and Subsurface Storage (NEXSS). At the core of NEXSS is a characterization of the channel geometry, geomorphic features, and related hydraulic drivers based on scaling equations from the literature and readily accessible information such as river discharge, bankfull width, median grain size, sinuosity, channel slope, and regional groundwater gradients. Multi-scale hyporheic flow is computed based on combining simple but powerful analytical and numerical expressions that have been previously published. We applied NEXSS across a broad range of geomorphic diversity in river reaches and synthetic river networks. NEXSS demonstrates that vertical exchange beneath submerged bedforms dominates hyporheic fluxes and turnover rates along the river corridor. Moreover, the hyporheic zone's potential for biogeochemical transformations is comparable across stream orders, but the abundance of lower-order channels results in a considerably higher cumulative effect for low-order streams. Thus, vertical exchange beneath submerged bedforms has more potential for biogeochemical transformations than lateral exchange beneath banks, although lateral exchange through meanders may be important in large rivers. These results have implications for predicting outcomes of river and basin management practices.

  20. Profile-likelihood Confidence Intervals in Item Response Theory Models.

    PubMed

    Chalmers, R Philip; Pek, Jolynn; Liu, Yang

    2017-01-01

    Confidence intervals (CIs) are fundamental inferential devices which quantify the sampling variability of parameter estimates. In item response theory, CIs have been primarily obtained from large-sample Wald-type approaches based on standard error estimates, derived from the observed or expected information matrix, after parameters have been estimated via maximum likelihood. An alternative approach to constructing CIs is to quantify sampling variability directly from the likelihood function with a technique known as profile-likelihood confidence intervals (PL CIs). In this article, we introduce PL CIs for item response theory models, compare PL CIs to classical large-sample Wald-type CIs, and demonstrate important distinctions among these CIs. CIs are then constructed for parameters directly estimated in the specified model and for transformed parameters which are often obtained post-estimation. Monte Carlo simulation results suggest that PL CIs perform consistently better than Wald-type CIs for both non-transformed and transformed parameters.

  1. MIIX reinvents itself, again.

    PubMed

    Maressa, V A

    1999-09-01

    The Medical Inter-Insurance Exchange (MIIX) converted from a reciprocal exchange to a stock company, on August 4, 1999. At the same time, MIIX completed an initial public offering of stock and is now listed on the New York Stock Exchange as The MIIX Group, Inc., under the symbol "MHU." In order to understand the necessity and process of this transformation, a review of the history and operation of MIIX is helpful.

  2. Reflections on Cyberspace as the New "Wired World of Education"

    ERIC Educational Resources Information Center

    Ward, Andrew; Prosser, Brian T.

    2011-01-01

    Developments in Information Technologies (ITs) like the Internet have transformed information exchange. Moreover, since information exchange and analysis are key aspects of the learning experience, these developments have had an important impact on education. Within this context, the important question concerns the sort of educational…

  3. Health information exchange reduces repeated diagnostic imaging for back pain.

    PubMed

    Bailey, James E; Pope, Rebecca A; Elliott, Elizabeth C; Wan, Jim Y; Waters, Teresa M; Frisse, Mark E

    2013-07-01

    This study seeks to determine whether health information exchange reduces repeated diagnostic imaging and related costs in emergency back pain evaluation. This was a longitudinal data analysis of health information exchange patient-visit data. All repeated emergency department (ED) patient visits for back pain with previous ED diagnostic imaging to a Memphis metropolitan area ED between August 1, 2007, and July 31, 2009, were included. Use of a regional health information exchange by ED personnel to access the patient's record during the emergency visit was the primary independent variable. Main outcomes included repeated lumbar or thoracic diagnostic imaging (radiograph, computed tomography [CT], or magnetic resonance imaging [MRI]) and total patient-visit estimated cost. One hundred seventy-nine (22.4%) of the 800 qualifying repeated back pain visits resulted in repeated diagnostic imaging (radiograph 84.9%, CT 6.1%, and MRI 9.5%). Health information exchange use in the study population was low, at 12.5%, and health care providers as opposed to administrative/nursing staff accounted for 80% of the total health information exchange use. Health information exchange use by any ED personnel was associated with reduced repeated diagnostic imaging (odds ratio 0.36; 95% confidence interval 0.18 to 0.71), as was physician or nurse practitioner health information exchange use (odds ratio 0.47; 95% confidence interval 0.23 to 0.96). No cost savings were associated with health information exchange use because of increased CT imaging when health care providers used health information exchange. Health information exchange use is associated with 64% lower odds of repeated diagnostic imaging in the emergency evaluation of back pain. Health information exchange effect on estimated costs was negligible. More studies are needed to evaluate specific strategies to increase health information exchange use and further decrease potentially unnecessary diagnostic imaging and associated costs of care. Copyright © 2013 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

  4. A subtle economy of time: Social media and the transformation of Indonesia's Islamic preacher economy.

    PubMed

    Slama, Martin

    2017-01-01

    The article is concerned with the latest developments in Indonesia's Islamic field. Its focus is on the role of social media in exchange relationships between Islamic preachers and their constituency. The article first discusses economic exchanges between preachers and their followers, and then it concentrates on social exchanges and how they are mediated today. Empirically, the article delivers insight into the concerns of mostly female Indonesian middle-class Muslims and shows how preachers have to adjust to the needs of their followers who are regularly online. Theoretically, the article offers a rereading of Pierre Bourdieu's classic work on forms of capital and their conversion. It emphasizes the temporal dimension of capital accumulation and conversion and explores the temporalities of online exchanges that have become constitutive of preacher-follower relationships. In doing so, it shows how Indonesia's Islamic preacher economy is currently transformed by these online exchanges, resulting in preacher-follower relationships that are characterized by dialogic constructions of Islamic authority. Being part of Indonesia's Islamic field, these changes in the Islamic preacher economy point to a broader trend in Indonesia's Islamic field toward greater sensitivity to the needs and worries of Indonesian middle-class Muslims.

  5. Rethinking the ICC Framework: Transformation and Telecollaboration

    ERIC Educational Resources Information Center

    Bohinski, Chesla Ann; Leventhal, Yumei

    2015-01-01

    This task-based study, designed with Helm and Guth's (2010) Telecollaboration 2.0 framework in mind, qualitatively investigated a telecollaborative exchange. Two second language (L2) Spanish participants and three L2 English participants carried out a six-week e-mail exchange that centered on specific holidays, giving researchers an opportunity to…

  6. Currency Exchange Rates.

    ERIC Educational Resources Information Center

    Siler, Carl R.

    This curriculum unit of the Muncie (Indiana) Southside High School is to simulate the dynamics of foreign currency exchange rates from the perspectives of: (1) a major U.S. corporation, ABB Power T & D Company, Inc., of Muncie, Indiana, a manufacturer of large power transformers for the domestic and foreign markets; and (2) individual…

  7. Facilitating Cross-Cultural Management Education through Global Faculty Exchanges

    ERIC Educational Resources Information Center

    Clinebell, Sharon K.; Kvedaraviciene, Ieva

    2013-01-01

    According to the AACSB International (Association to Advance Collegiate Schools of Business) (AACSB International, 2011), the next big transformational wave to hit business schools is globalization. Globalizing the faculty is one strategy for enhancing the globalization of business schools and using global faculty exchanges is one method to…

  8. Microscopic theory of cation exchange in CdSe nanocrystals.

    PubMed

    Ott, Florian D; Spiegel, Leo L; Norris, David J; Erwin, Steven C

    2014-10-10

    Although poorly understood, cation-exchange reactions are increasingly used to dope or transform colloidal semiconductor nanocrystals (quantum dots). We use density-functional theory and kinetic Monte Carlo simulations to develop a microscopic theory that explains structural, optical, and electronic changes observed experimentally in Ag-cation-exchanged CdSe nanocrystals. We find that Coulomb interactions, both between ionized impurities and with the polarized nanocrystal surface, play a key role in cation exchange. Our theory also resolves several experimental puzzles related to photoluminescence and electrical behavior in CdSe nanocrystals doped with Ag.

  9. Leadership, innovation climate, and attitudes toward evidence-based practice during a statewide implementation.

    PubMed

    Aarons, Gregory A; Sommerfeld, David H

    2012-04-01

    Leadership is important in practice change, yet there are few studies addressing this issue in mental health and social services. This study examined the differential roles of transformational (i.e., charismatic) leadership and leader-member exchange (i.e., the relationship between a supervisor and their direct service providers) on team innovation climate (i.e., openness to new innovations) and provider attitudes toward adopting evidence-based practice (EBP) during a statewide evidence-based practice implementation (EBPI) of an intervention to reduce child neglect. Participants were 140 case-managers in 30 teams providing home-based services to families in a statewide child-welfare system. Teams were assigned by region to EBPI or services as usual (SAU) conditions. Multiple group path analysis was used to examine associations of transformational leadership and leader-member exchange with innovation climate and attitudes toward adoption and use of EBP. Transformational leadership predicted higher innovation climate during implementation, whereas leader-member exchange predicted higher innovation climate during SAU. Innovation climate was, in turn, associated with more positive attitudes toward EBP for the EBPI group. Strategies designed to enhance supervisor transformational leadership have the potential to facilitate implementation efforts by promoting a strong climate for EBPI and positive provider attitudes toward adoption and use of EBP. Copyright © 2012 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  10. Evaluation of direct-exchange areas for a cylindrical enclosure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sika, J.

    1991-11-01

    This paper reports on a method for calculating the radiative heat transfer direct-exchange areas for surface-to-surface, volume-to-surface, and volume-to-volume pairs of zones in axisymmetric cylindrical geometries. With this method the calculation of the direct-exchange areas can be transformed from the original four-, five-, and sixfold integrals in the defining relations to just single and/or double integrals. Gray gas with absorption coefficient K is assumed.

  11. Transformational Events

    ERIC Educational Resources Information Center

    Denning, Peter J.; Hiles, John E.

    2006-01-01

    Transformational Events is a new pedagogic pattern that explains how innovations (and other transformations) happened. The pattern is three temporal stages: an interval of increasingly unsatisfactory ad hoc solutions to a persistent problem (the "mess"), an offer of an invention or of a new way of thinking, and a period of widespread adoption and…

  12. Ehrenfest model with large jumps in finance

    NASA Astrophysics Data System (ADS)

    Takahashi, Hisanao

    2004-02-01

    Changes (returns) in stock index prices and exchange rates for currencies are argued, based on empirical data, to obey a stable distribution with characteristic exponent α<2 for short sampling intervals and a Gaussian distribution for long sampling intervals. In order to explain this phenomenon, an Ehrenfest model with large jumps (ELJ) is introduced to explain the empirical density function of price changes for both short and long sampling intervals.

  13. Plastic biliary stent patency in patients with locally advanced pancreatic adenocarcinoma receiving downstaging chemotherapy.

    PubMed

    Ge, Phillip S; Hamerski, Christopher M; Watson, Rabindra R; Komanduri, Srinadh; Cinnor, Birtukan B; Bidari, Kiran; Klapman, Jason B; Lin, Cui L; Shah, Janak N; Wani, Sachin; Donahue, Timothy R; Muthusamy, V Raman

    2015-02-01

    Plastic stents in patients with biliary obstruction caused by pancreatic adenocarcinoma are typically exchanged at 3-month intervals. Plastic stents may have reduced durability in patients receiving chemotherapy. To determine the duration of plastic biliary stent patency in patients undergoing chemotherapy for pancreatic adenocarcinoma. Retrospective, multicenter cohort study. Three tertiary academic referral centers. A total of 173 patients receiving downstaging chemotherapy for locally advanced or borderline resectable pancreatic adenocarcinoma from 1996 to 2013. Placement of 10F or larger plastic biliary stents. Primary outcome was overall duration of stent patency. Secondary outcomes included the incidence of premature stent exchange (because of cholangitis or jaundice) and hospitalization rates. A total of 233 plastic stents were placed, and the overall median duration of stent patency was 53 days (interquartile range [IQR] 25-99 days). Eighty-seven stents were removed at the time of surgical resection, and 63 stents were exchanged routinely per protocol. The remaining 83 stent exchanges were performed for worsening liver function test results, jaundice, or cholangitis, representing a 35.6% rate of premature stent exchange. The median stent patency duration in the premature stent exchange group was 49 days (IQR 25-91 days) with a 44.6% hospitalization rate. The overall rate of cholangitis was 15.0% of stent exchanges, occurring a median of 56 days after stent placement (IQR 26-89 days). Retrospective study. Plastic biliary stents placed during chemotherapy/chemoradiation for pancreatic adenocarcinoma have a shorter-than-expected patency duration, and a substantial number of patients will require premature stent exchange. Consideration should be given to shortening the interval for plastic biliary stent exchange. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  14. Recurrence spectra of a helium atom in parallel electric and magnetic fields

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Dehua; Department of Mathematics and Physics, Shandong Architecture and Engineering Institute, Jinan 250014, People's Republic of China; Ding, Shiliang

    2003-08-01

    A model potential for the general Rydberg atom is put forward, which includes not only the Coulomb interaction potential and the core-attractive potential, but also the exchange potential between the excited electron and other electrons. Using the region-splitting consistent and iterative method, we calculated the scaled recurrence spectra of the helium atom in parallel electric and magnetic fields and the closed orbits in the corresponding classical system have also been obtained. In order to remove the Coulomb singularity of the classical motion of Hamiltonian, we implement the Kustaanheimo-Stiefel transformation, which transforms the system from a three-dimensional to a four-dimensional one.more » The Fourier-transformed spectra of the helium atom has allowed direct comparison between peaks in such a plot and the scaled action values of closed orbits. Considering the exchange potential, the number of the closed orbits increased, which led to more peaks in the recurrence spectra. The results are compared with those of the hydrogen case, which shows that the core-scattered effects and the electron exchange potential play an important role in the multielectron Rydberg atom.« less

  15. Social Values, Subjective Transformations, and Cooperation in Social Dilemmas

    ERIC Educational Resources Information Center

    Simpson, Brent

    2004-01-01

    A persistent anomaly in the social dilemmas literature is the surprisingly high level of cooperation observed in experimental investigations of the one-shot Prisoners' Dilemma (PD). The exchange heuristic hypothesis and related approaches explain this finding by arguing that actors subjectively transform PD into the Assurance Dilemma. A tendency…

  16. Predicting protein aggregation during storage in lyophilized solids using solid state amide hydrogen/deuterium exchange with mass spectrometric analysis (ssHDX-MS).

    PubMed

    Moorthy, Balakrishnan S; Schultz, Steven G; Kim, Sherry G; Topp, Elizabeth M

    2014-06-02

    Solid state amide hydrogen/deuterium exchange with mass spectrometric analysis (ssHDX-MS) was used to assess the conformation of myoglobin (Mb) in lyophilized formulations, and the results correlated with the extent of aggregation during storage. Mb was colyophilized with sucrose (1:1 or 1:8 w/w), mannitol (1:1 w/w), or NaCl (1:1 w/w) or in the absence of excipients. Immediately after lyophilization, samples of each formulation were analyzed by ssHDX-MS and Fourier transform infrared spectroscopy (FTIR) to assess Mb conformation, and by dynamic light scattering (DLS) and size exclusion chromatography (SEC) to determine the extent of aggregation. The remaining samples were then placed on stability at 25 °C and 60% RH or 40 °C and 75% RH for up to 1 year, withdrawn at intervals, and analyzed for aggregate content by SEC and DLS. In ssHDX-MS of samples immediately after lyophilization (t = 0), Mb was less deuterated in solids containing sucrose (1:1 and 1:8 w/w) than in those containing mannitol (1:1 w/w), NaCl (1:1 w/w), or Mb alone. Deuterium uptake kinetics and peptide mass envelopes also indicated greater Mb structural perturbation in mannitol, NaCl, or Mb-alone samples at t = 0. The extent of deuterium incorporation and kinetic parameters related to rapidly and slowly exchanging amide pools (Nfast, Nslow), measured at t = 0, were highly correlated with the extent of aggregation on storage as measured by SEC. In contrast, the extent of aggregation was weakly correlated with FTIR band intensity and peak position measured at t = 0. The results support the use of ssHDX-MS as a formulation screening tool in developing lyophilized protein drug products.

  17. Phase Space Exchange in Thick Wedge Absorbers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Neuffer, David

    The problem of phase space exchange in wedge absorbers with ionization cooling is discussed. The wedge absorber exchanges transverse and longitudinal phase space by introducing a position-dependent energy loss. In this paper we note that the wedges used with ionization cooling are relatively thick, so that single wedges cause relatively large changes in beam phase space. Calculation methods adapted to such “thick wedge” cases are presented, and beam phase-space transformations through such wedges are discussed.

  18. Response of Autonomic Nervous System to Body Positions:

    NASA Astrophysics Data System (ADS)

    Xu, Aiguo; Gonnella, G.; Federici, A.; Stramaglia, S.; Simone, F.; Zenzola, A.; Santostasi, R.

    Two mathematical methods, the Fourier and wavelet transforms, were used to study the short term cardiovascular control system. Time series, picked from electrocardiogram and arterial blood pressure lasting 6 minutes, were analyzed in supine position (SUP), during the first (HD1) and the second parts (HD2) of 90° head down tilt, and during recovery (REC). The wavelet transform was performed using the Haar function of period T=2j (j=1,2,...,6) to obtain wavelet coefficients. Power spectra components were analyzed within three bands, VLF (0.003-0.04), LF (0.04-0.15) and HF (0.15-0.4) with the frequency unit cycle/interval. Wavelet transform demonstrated a higher discrimination among all analyzed periods than the Fourier transform. For the Fourier analysis, the LF of R-R intervals and VLF of systolic blood pressure show more evident difference for different body positions. For the wavelet analysis, the systolic blood pressures show much more evident differences than the R-R intervals. This study suggests a difference in the response of the vessels and the heart to different body positions. The partial dissociation between VLF and LF results is a physiologically relevant finding of this work.

  19. Partial-Interval Estimation of Count: Uncorrected and Poisson-Corrected Error Levels

    ERIC Educational Resources Information Center

    Yoder, Paul J.; Ledford, Jennifer R.; Harbison, Amy L.; Tapp, Jon T.

    2018-01-01

    A simulation study that used 3,000 computer-generated event streams with known behavior rates, interval durations, and session durations was conducted to test whether the main and interaction effects of true rate and interval duration affect the error level of uncorrected and Poisson-transformed (i.e., "corrected") count as estimated by…

  20. A novel recursive Fourier transform for nonuniform sampled signals: application to heart rate variability spectrum estimation.

    PubMed

    Holland, Alexander; Aboy, Mateo

    2009-07-01

    We present a novel method to iteratively calculate discrete Fourier transforms for discrete time signals with sample time intervals that may be widely nonuniform. The proposed recursive Fourier transform (RFT) does not require interpolation of the samples to uniform time intervals, and each iterative transform update of N frequencies has computational order N. Because of the inherent non-uniformity in the time between successive heart beats, an application particularly well suited for this transform is power spectral density (PSD) estimation for heart rate variability. We compare RFT based spectrum estimation with Lomb-Scargle Transform (LST) based estimation. PSD estimation based on the LST also does not require uniform time samples, but the LST has a computational order greater than Nlog(N). We conducted an assessment study involving the analysis of quasi-stationary signals with various levels of randomly missing heart beats. Our results indicate that the RFT leads to comparable estimation performance to the LST with significantly less computational overhead and complexity for applications requiring iterative spectrum estimations.

  1. Estimation of reference intervals from small samples: an example using canine plasma creatinine.

    PubMed

    Geffré, A; Braun, J P; Trumel, C; Concordet, D

    2009-12-01

    According to international recommendations, reference intervals should be determined from at least 120 reference individuals, which often are impossible to achieve in veterinary clinical pathology, especially for wild animals. When only a small number of reference subjects is available, the possible bias cannot be known and the normality of the distribution cannot be evaluated. A comparison of reference intervals estimated by different methods could be helpful. The purpose of this study was to compare reference limits determined from a large set of canine plasma creatinine reference values, and large subsets of this data, with estimates obtained from small samples selected randomly. Twenty sets each of 120 and 27 samples were randomly selected from a set of 1439 plasma creatinine results obtained from healthy dogs in another study. Reference intervals for the whole sample and for the large samples were determined by a nonparametric method. The estimated reference limits for the small samples were minimum and maximum, mean +/- 2 SD of native and Box-Cox-transformed values, 2.5th and 97.5th percentiles by a robust method on native and Box-Cox-transformed values, and estimates from diagrams of cumulative distribution functions. The whole sample had a heavily skewed distribution, which approached Gaussian after Box-Cox transformation. The reference limits estimated from small samples were highly variable. The closest estimates to the 1439-result reference interval for 27-result subsamples were obtained by both parametric and robust methods after Box-Cox transformation but were grossly erroneous in some cases. For small samples, it is recommended that all values be reported graphically in a dot plot or histogram and that estimates of the reference limits be compared using different methods.

  2. Evaluation Of Statistical Models For Forecast Errors From The HBV-Model

    NASA Astrophysics Data System (ADS)

    Engeland, K.; Kolberg, S.; Renard, B.; Stensland, I.

    2009-04-01

    Three statistical models for the forecast errors for inflow to the Langvatn reservoir in Northern Norway have been constructed and tested according to how well the distribution and median values of the forecasts errors fit to the observations. For the first model observed and forecasted inflows were transformed by the Box-Cox transformation before a first order autoregressive model was constructed for the forecast errors. The parameters were conditioned on climatic conditions. In the second model the Normal Quantile Transformation (NQT) was applied on observed and forecasted inflows before a similar first order autoregressive model was constructed for the forecast errors. For the last model positive and negative errors were modeled separately. The errors were first NQT-transformed before a model where the mean values were conditioned on climate, forecasted inflow and yesterday's error. To test the three models we applied three criterions: We wanted a) the median values to be close to the observed values; b) the forecast intervals to be narrow; c) the distribution to be correct. The results showed that it is difficult to obtain a correct model for the forecast errors, and that the main challenge is to account for the auto-correlation in the errors. Model 1 and 2 gave similar results, and the main drawback is that the distributions are not correct. The 95% forecast intervals were well identified, but smaller forecast intervals were over-estimated, and larger intervals were under-estimated. Model 3 gave a distribution that fits better, but the median values do not fit well since the auto-correlation is not properly accounted for. If the 95% forecast interval is of interest, Model 2 is recommended. If the whole distribution is of interest, Model 3 is recommended.

  3. Polar Aprotic Modifiers for Chromatographic Separation and Back-Exchange Reduction for Protein Hydrogen/Deuterium Exchange Monitored by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Valeja, Santosh G.; Emmett, Mark R.; Marshall, Alan G.

    2012-04-01

    Hydrogen/deuterium exchange monitored by mass spectrometry is an important non-perturbing tool to study protein structure and protein-protein interactions. However, water in the reversed-phase liquid chromatography mobile phase leads to back-exchange of D for H during chromatographic separation of proteolytic peptides following H/D exchange, resulting in incorrect identification of fast-exchanging hydrogens as unexchanged hydrogens. Previously, fast high-performance liquid chromatography (HPLC) and supercritical fluid chromatography have been shown to decrease back-exchange. Here, we show that replacement of up to 40% of the water in the LC mobile phase by the modifiers, dimethylformamide (DMF) and N-methylpyrrolidone (NMP) (i.e., polar organic modifiers that lack rapid exchanging hydrogens), significantly reduces back-exchange. On-line LC micro-ESI FT-ICR MS resolves overlapped proteolytic peptide isotopic distributions, allowing for quantitative determination of the extent of back-exchange. The DMF modified solvent composition also improves chromatographic separation while reducing back-exchange relative to conventional solvent.

  4. Detecting Pulsing Denial-of-Service Attacks with Nondeterministic Attack Intervals

    NASA Astrophysics Data System (ADS)

    Luo, Xiapu; Chan, Edmond W. W.; Chang, Rocky K. C.

    2009-12-01

    This paper addresses the important problem of detecting pulsing denial of service (PDoS) attacks which send a sequence of attack pulses to reduce TCP throughput. Unlike previous works which focused on a restricted form of attacks, we consider a very broad class of attacks. In particular, our attack model admits any attack interval between two adjacent pulses, whether deterministic or not. It also includes the traditional flooding-based attacks as a limiting case (i.e., zero attack interval). Our main contribution is Vanguard, a new anomaly-based detection scheme for this class of PDoS attacks. The Vanguard detection is based on three traffic anomalies induced by the attacks, and it detects them using a CUSUM algorithm. We have prototyped Vanguard and evaluated it on a testbed. The experiment results show that Vanguard is more effective than the previous methods that are based on other traffic anomalies (after a transformation using wavelet transform, Fourier transform, and autocorrelation) and detection algorithms (e.g., dynamic time warping).

  5. Exsolution of Ca-clinopyroxene from orthopyroxene aided by deformation

    USGS Publications Warehouse

    Kirby, S.H.; Etheridge, M.A.

    1981-01-01

    Monoclinic calcium-poor shear-transformation lamellae and calcium-rich exsolution lamellae occur parallel to (100) in orthopyroxene. The formation of both structures from an orthopyroxene host involves a shear on (100) parallel to [001], with additional cation exchange in the exsolution case. The shear transformation involves a macroscopic simple shear angle of 13.3?? (shear strain of 0.236) and produces a specific a-axis orientation with respect to the sense of shear; we have found that this orientation dominates in exsolution lamellae in kinked orthopyroxene, where the sense of shear is known. In undeformed orthopyroxene, there is generally no preferred sense of orientation of the monoclinic a axes. We advance a specific model for exsolution involving nucleation and growth by shear transformation combined with cation exchange, thus circumventing the classical nucleation barrier and permitting exsolution at lower solute supersaturations. ?? 1981 Springer-Verlag.

  6. Correlation between pairing initiation sites, recombination nodules and meiotic recombination in Sordaria macrospora.

    PubMed

    Zickler, D; Moreau, P J; Huynh, A D; Slezec, A M

    1992-09-01

    The decrease of meiotic exchanges (crossing over and conversion) in two mutants of Sordaria macrospora correlated strongly with a reduction of chiasmata and of both types of "recombination nodules." Serial section reconstruction electron microscopy was used to compare the synapsis pattern of meiotic prophase I in wild type and mutants. First, synapsis occurred but the number of synaptonemal complex initiation sites was reduced in both mutants. Second, this reduction was accompanied by, or resulted in, modifications of the pattern of synapsis. Genetic and synaptonemal complex maps were compared in three regions along one chromosome arm divided into well marked intervals. Reciprocal exchange frequencies and number of recombination nodules correlated in wild type in the three analyzed intervals, but disparity was found between the location of recombination nodules and exchanges in the mutants. Despite the twofold exchange decrease, sections of the genome such as the short arm of chromosome 2 and telomere regions were sheltered from nodule decrease and from pairing modifications. This indicated a certain amount of diversity in the control of these features and suggested that exchange frequency was dependent not only on the amount of effective pairing but also on the localization of the pairing sites, as revealed by the synaptonemal complex progression in the mutants.

  7. Correlation between Pairing Initiation Sites, Recombination Nodules and Meiotic Recombination in Sordaria Macrospora

    PubMed Central

    Zickler, D.; Moreau, PJF.; Huynh, A. D.; Slezec, A. M.

    1992-01-01

    The decrease of meiotic exchanges (crossing over and conversion) in two mutants of Sordaria macrospora correlated strongly with a reduction of chiasmata and of both types of ``recombination nodules.'' Serial section reconstruction electron microscopy was used to compare the synapsis pattern of meiotic prophase I in wild type and mutants. First, synapsis occurred but the number of synaptonemal complex initiation sites was reduced in both mutants. Second, this reduction was accompanied by, or resulted in, modifications of the pattern of synapsis. Genetic and synaptonemal complex maps were compared in three regions along one chromosome arm divided into well marked intervals. Reciprocal exchange frequencies and number of recombination nodules correlated in wild type in the three analyzed intervals, but disparity was found between the location of recombination nodules and exchanges in the mutants. Despite the twofold exchange decrease, sections of the genome such as the short arm of chromosome 2 and telomere regions were sheltered from nodule decrease and from pairing modifications. This indicated a certain amount of diversity in the control of these features and suggested that exchange frequency was dependent not only on the amount of effective pairing but also on the localization of the pairing sites, as revealed by the synaptonemal complex progression in the mutants. PMID:1398050

  8. Thickness dependent exchange bias in martensitic epitaxial Ni-Mn-Sn thin films

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Behler, Anna; Department of Physics, Institute for Solid State Physics, Dresden University of Technology, 01062 Dresden; Teichert, Niclas

    2013-12-15

    A thickness dependent exchange bias in the low temperature martensitic state of epitaxial Ni-Mn-Sn thin films is found. The effect can be retained down to very small thicknesses. For a Ni{sub 50}Mn{sub 32}Sn{sub 18} thin film, which does not undergo a martensitic transformation, no exchange bias is observed. Our results suggest that a significant interplay between ferromagnetic and antiferromagnetic regions, which is the origin for exchange bias, is only present in the martensite. The finding is supported by ab initio calculations showing that the antiferromagnetic order is stabilized in the phase.

  9. 75 FR 51306 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-19

    ... systems capacity to handle the additional traffic associated with the listing and trading of $1 strikes... Relating to Establishing Strike Price Intervals for Options on Trust Issued Receipts, Including Holding... Rules of the Boston Options Exchange Group, LLC (``BOX'') to establish strike price intervals for...

  10. 75 FR 77925 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-14

    ... Establish Strike Price Intervals and Trading Hours for Options on Index-Linked Securities December 8, 2010... Business) of the Rules of the Boston Options Exchange Group, LLC (``BOX'') to establish strike price... proposing to establish strike price intervals and trading hours for these products. The Securities and...

  11. Maximum likelihood estimation for semiparametric transformation models with interval-censored data

    PubMed Central

    Mao, Lu; Lin, D. Y.

    2016-01-01

    Abstract Interval censoring arises frequently in clinical, epidemiological, financial and sociological studies, where the event or failure of interest is known only to occur within an interval induced by periodic monitoring. We formulate the effects of potentially time-dependent covariates on the interval-censored failure time through a broad class of semiparametric transformation models that encompasses proportional hazards and proportional odds models. We consider nonparametric maximum likelihood estimation for this class of models with an arbitrary number of monitoring times for each subject. We devise an EM-type algorithm that converges stably, even in the presence of time-dependent covariates, and show that the estimators for the regression parameters are consistent, asymptotically normal, and asymptotically efficient with an easily estimated covariance matrix. Finally, we demonstrate the performance of our procedures through simulation studies and application to an HIV/AIDS study conducted in Thailand. PMID:27279656

  12. The τq-Fourier transform: Covariance and uniqueness

    NASA Astrophysics Data System (ADS)

    Kalogeropoulos, Nikolaos

    2018-05-01

    We propose an alternative definition for a Tsallis entropy composition-inspired Fourier transform, which we call “τq-Fourier transform”. We comment about the underlying “covariance” on the set of algebraic fields that motivates its introduction. We see that the definition of the τq-Fourier transform is automatically invertible in the proper context. Based on recent results in Fourier analysis, it turns that the τq-Fourier transform is essentially unique under the assumption of the exchange of the point-wise product of functions with their convolution.

  13. Natural Genetic Transformation Generates a Population of Merodiploids in Streptococcus pneumoniae

    PubMed Central

    Zomer, Aldert; Bootsma, Hester J.; Prudhomme, Marc; Granadel, Chantal; Hermans, Peter W. M.; Polard, Patrice; Martin, Bernard; Claverys, Jean-Pierre

    2013-01-01

    Partial duplication of genetic material is prevalent in eukaryotes and provides potential for evolution of new traits. Prokaryotes, which are generally haploid in nature, can evolve new genes by partial chromosome duplication, known as merodiploidy. Little is known about merodiploid formation during genetic exchange processes, although merodiploids have been serendipitously observed in early studies of bacterial transformation. Natural bacterial transformation involves internalization of exogenous donor DNA and its subsequent integration into the recipient genome by homology. It contributes to the remarkable plasticity of the human pathogen Streptococcus pneumoniae through intra and interspecies genetic exchange. We report that lethal cassette transformation produced merodiploids possessing both intact and cassette-inactivated copies of the essential target gene, bordered by repeats (R) corresponding to incomplete copies of IS861. We show that merodiploidy is transiently stimulated by transformation, and only requires uptake of a ∼3-kb DNA fragment partly repeated in the chromosome. We propose and validate a model for merodiploid formation, providing evidence that tandem-duplication (TD) formation involves unequal crossing-over resulting from alternative pairing and interchromatid integration of R. This unequal crossing-over produces a chromosome dimer, resolution of which generates a chromosome with the TD and an abortive chromosome lacking the duplicated region. We document occurrence of TDs ranging from ∼100 to ∼900 kb in size at various chromosomal locations, including by self-transformation (transformation with recipient chromosomal DNA). We show that self-transformation produces a population containing many different merodiploid cells. Merodiploidy provides opportunities for evolution of new genetic traits via alteration of duplicated genes, unrestricted by functional selective pressure. Transient stimulation of a varied population of merodiploids by transformation, which can be triggered by stresses such as antibiotic treatment in S. pneumoniae, reinforces the plasticity potential of this bacterium and transformable species generally. PMID:24086154

  14. Natural genetic transformation generates a population of merodiploids in Streptococcus pneumoniae.

    PubMed

    Johnston, Calum; Caymaris, Stéphanie; Zomer, Aldert; Bootsma, Hester J; Prudhomme, Marc; Granadel, Chantal; Hermans, Peter W M; Polard, Patrice; Martin, Bernard; Claverys, Jean-Pierre

    2013-01-01

    Partial duplication of genetic material is prevalent in eukaryotes and provides potential for evolution of new traits. Prokaryotes, which are generally haploid in nature, can evolve new genes by partial chromosome duplication, known as merodiploidy. Little is known about merodiploid formation during genetic exchange processes, although merodiploids have been serendipitously observed in early studies of bacterial transformation. Natural bacterial transformation involves internalization of exogenous donor DNA and its subsequent integration into the recipient genome by homology. It contributes to the remarkable plasticity of the human pathogen Streptococcus pneumoniae through intra and interspecies genetic exchange. We report that lethal cassette transformation produced merodiploids possessing both intact and cassette-inactivated copies of the essential target gene, bordered by repeats (R) corresponding to incomplete copies of IS861. We show that merodiploidy is transiently stimulated by transformation, and only requires uptake of a ~3-kb DNA fragment partly repeated in the chromosome. We propose and validate a model for merodiploid formation, providing evidence that tandem-duplication (TD) formation involves unequal crossing-over resulting from alternative pairing and interchromatid integration of R. This unequal crossing-over produces a chromosome dimer, resolution of which generates a chromosome with the TD and an abortive chromosome lacking the duplicated region. We document occurrence of TDs ranging from ~100 to ~900 kb in size at various chromosomal locations, including by self-transformation (transformation with recipient chromosomal DNA). We show that self-transformation produces a population containing many different merodiploid cells. Merodiploidy provides opportunities for evolution of new genetic traits via alteration of duplicated genes, unrestricted by functional selective pressure. Transient stimulation of a varied population of merodiploids by transformation, which can be triggered by stresses such as antibiotic treatment in S. pneumoniae, reinforces the plasticity potential of this bacterium and transformable species generally.

  15. Turning Inspiration into Educational Innovation

    ERIC Educational Resources Information Center

    Spencer, Danielle

    2016-01-01

    In summarizing this report Danielle Spencer states: "Japan truly was transformational for me. At that time I saw myself as a nurse just pretending to be a teacher. The Australia-Japan Foundation (AJF), Japan exchange enabled me to be a teacher who used to be a nurse." How did this transformation come about? Each year, a national…

  16. Structure-conserving spontaneous transformations between nanoparticles

    NASA Astrophysics Data System (ADS)

    Krishnadas, K. R.; Baksi, Ananya; Ghosh, Atanu; Natarajan, Ganapati; Pradeep, Thalappil

    2016-11-01

    Ambient, structure- and topology-preserving chemical reactions between two archetypal nanoparticles, Ag25(SR)18 and Au25(SR)18, are presented. Despite their geometric robustness and electronic stability, reactions between them in solution produce alloys, AgmAun(SR)18 (m+n=25), keeping their M25(SR)18 composition, structure and topology intact. We demonstrate that a mixture of Ag25(SR)18 and Au25(SR)18 can be transformed to any arbitrary alloy composition, AgmAun(SR)18 (n=1-24), merely by controlling the reactant compositions. We capture one of the earliest events of the process, namely the formation of the dianionic adduct, (Ag25Au25(SR)36)2-, by electrospray ionization mass spectrometry. Molecular docking simulations and density functional theory (DFT) calculations also suggest that metal atom exchanges occur through the formation of an adduct between the two clusters. DFT calculations further confirm that metal atom exchanges are thermodynamically feasible. Such isomorphous transformations between nanoparticles imply that microscopic pieces of matter can be transformed completely to chemically different entities, preserving their structures, at least in the nanometric regime.

  17. Single-site trinuclear copper oxygen clusters in mordenite for selective conversion of methane to methanol.

    PubMed

    Grundner, Sebastian; Markovits, Monica A C; Li, Guanna; Tromp, Moniek; Pidko, Evgeny A; Hensen, Emiel J M; Jentys, Andreas; Sanchez-Sanchez, Maricruz; Lercher, Johannes A

    2015-06-25

    Copper-exchanged zeolites with mordenite structure mimic the nuclearity and reactivity of active sites in particulate methane monooxygenase, which are enzymes able to selectively oxidize methane to methanol. Here we show that the mordenite micropores provide a perfect confined environment for the highly selective stabilization of trinuclear copper-oxo clusters that exhibit a high reactivity towards activation of carbon-hydrogen bonds in methane and its subsequent transformation to methanol. The similarity with the enzymatic systems is also implied from the similarity of the reversible rearrangements of the trinuclear clusters occurring during the selective transformations of methane along the reaction path towards methanol, in both the enzyme system and copper-exchanged mordenite.

  18. Fourier-transform infrared derivative spectroscopy with an improved signal-to-noise ratio.

    PubMed

    Fetterman, M R

    2005-09-01

    Infrared derivative spectroscopy is a useful technique for finding peaks hidden in broad spectral features. A data acquisition technique is shown that will improve the signal-to-noise ratio (SNR) of Fourier-transform infrared (FTIR) derivative spectroscopy. Typically, in a FTIR measurement one samples each point for the same time interval. The effect of using a graded time interval is studied. The simulations presented show that the SNR of first-derivative FTIR spectroscopy will improve by 15% and that the SNR of second-derivative FTIR will improve by 34%.

  19. 77 FR 33543 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-06

    ... Term Option Series Program (``STOS Program'') to permit, during the expiration week of an option class... rule to open for trading Short Term Option Series at $0.50 strike price intervals for option classes... Short Term Option Series at $0.50 strike price intervals for option classes that trade in one dollar...

  20. 75 FR 66402 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-28

    ... necessary systems capacity to handle the additional traffic associated with the expanded range of strike... Effectiveness of Proposed Rule Change To Expand the Range of Strike Price Intervals for VIX Options October 21... amend Rule 24.9.01(e), Terms of Index Option Contracts, to expand the range of strike price intervals...

  1. The effect of short-duration sprint interval exercise on plasma postprandial triacylglycerol levels in young men.

    PubMed

    Allen, Edward; Gray, Partick; Kollias-Pearson, Angeliki; Oag, Erlend; Pratt, Katrina; Henderson, Jennifer; Gray, Stuart Robert

    2014-01-01

    It is well established that regular exercise can reduce the risk of cardiovascular disease, although the most time-efficient exercise protocol to confer benefits has yet to be established. The aim of the current study was to determine the effects of short-duration sprint interval exercise on postprandial triacylglycerol. Fifteen healthy male participants completed two 2 day trials. On day 1, participants rested (control) or carried out twenty 6 s sprints, interspersed with 24 s recovery (sprint interval exercise--14 min for total exercise session). On day 2, participants consumed a high-fat meal for breakfast with blood samples collected at baseline, 2 h and 4 h. Gas exchange was also measured at these time points. On day 2 of control and sprint interval exercise trials, there were no differences (P < 0.05) between trials in plasma glucose, triacylglycerol, insulin or respiratory exchange ratio (RER). The area under the curve for plasma triacylglycerol was 7.67 ± 2.37 mmol · l(-1) x 4 h(-1) in the control trial and 7.26 ± 2.49 mmol · l(-1) x 4 h(-1) in the sprint interval exercise trial. Although the sprint exercise protocol employed had no significant effect on postprandial triacylglycerol, there was a clear variability in responses that warrants further investigation.

  2. Preparation and characterization of (St-DVB-MAA) ion exchange resins

    NASA Astrophysics Data System (ADS)

    Jiang, Shanquan; Sun, Xiangwei; Ling, Lixing; Wang, Shumin; Wu, Wufeng; Cheng, Shihong; Hu, Yue; Zhong, Chunyan

    2017-08-01

    In this paper, used polyvinyl alcohol as dispersing agent, Benzoyl peroxide as initiator of polymerization, Divinyl benzene as cross-linking agent, Styrene and 2-Methylpropenoic acid as monomer, ion exchange resin (copolymer of St-DVB-MAA)were prepared by suspension polymerization on 80°C. The structures, components and properties of the prepared composite micro gels were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA). The experiment of ion exchange was conducted by resin to deal with copper ions in the solution. The result showed that performance of the ion exchange capacity was excellent, which impacted by pH.

  3. The NASA Scientific and Technical Information (STI) Program's Implementation of Open Archives Initiative (OAI) for Data Interoperability and Data Exchange.

    ERIC Educational Resources Information Center

    Rocker, JoAnne; Roncaglia, George J.; Heimerl, Lynn N.; Nelson, Michael L.

    Interoperability and data-exchange are critical for the survival of government information management programs. E-government initiatives are transforming the way the government interacts with the public. More information is to be made available through Web-enabled technologies. Programs such as the NASA's Scientific and Technical Information (STI)…

  4. Special Relativity Kinematics with Anisotropic Propagation of Light and Correspondence Principle

    NASA Astrophysics Data System (ADS)

    Burde, Georgy I.

    2016-12-01

    The purpose of the present paper is to develop kinematics of the special relativity with an anisotropy of the one-way speed of light. As distinct from a common approach, when the issue of anisotropy of the light propagation is placed into the context of conventionality of distant simultaneity, it is supposed that an anisotropy of the one-way speed of light is due to a real space anisotropy. In that situation, some assumptions used in developing the standard special relativity kinematics are not valid so that the "anisotropic special relativity" kinematics should be developed based on the first principles, without refereeing to the relations of the standard relativity theory. In particular, using condition of invariance of the interval between two events becomes unfounded in the presence of anisotropy of space since the standard proofs drawing the interval invariance from the invariance of equation of light propagation are not valid in that situation. Instead, the invariance of the equation of light propagation (with an anisotropy of the one-way speed of light incorporated), which is a physical law, should be taken as a first principle. A number of other physical requirements, associativity, reciprocity and so on are satisfied by the requirement that the transformations between the frames form a group. Finally, the correspondence principle is to be satisfied which implies that the coordinate transformations should turn into the Galilean transformations in the limit of small velocities. The above formulation based on the invariance and group property suggests applying the Lie group theory apparatus which includes the following steps: constructing determining equations for the infinitesimal group generators using the invariance condition; solving the determining equations; specifying the solutions using the correspondence principle; defining the finite transformations by solving the Lie equations; relating the group parameter to physical parameters. The transformations derived in such a way, as distinct from the transformations derived in the context of conventionality of distant simultaneity, cannot be converted into the standard Lorentz transformations by a coordinate (synchrony) change. The anisotropic nature of the presented transformations manifests itself in that they do not leave the interval invariant but only provide the conformal invariance of the interval. The relations that represent measurable effects include the conformal factor which depends on the relative velocity of the frames and the anisotropy degree. It is important to note the use of the correspondence principle as a heuristic principle which allows to relate the conformal factor to the anisotropy degree and thus completely specify the transformations and observable quantities.

  5. Formation of Semimetallic Cobalt Telluride Nanotube Film via Anion Exchange Tellurization Strategy in Aqueous Solution for Electrocatalytic Applications.

    PubMed

    Patil, Supriya A; Kim, Eun-Kyung; Shrestha, Nabeen K; Chang, Jinho; Lee, Joong Kee; Han, Sung-Hwan

    2015-11-25

    Metal telluride nanostructures have demonstrated several potential applications particularly in harvesting and storing green energy. Metal tellurides are synthesized by tellurization process performed basically at high temperature in reducing gas atmosphere, which makes the process expensive and complicated. The development of a facile and economical process for desirable metal telluride nanostructures without complicated manipulation is still a challenge. In an effort to develop an alternative strategy of tellurization, herein we report a thin film formation of self-standing cobalt telluride nanotubes on various conducting and nonconducting substrates using a simple binder-free synthetic strategy based on anion exchange transformation from a thin film of cobalt hydroxycarbonate nanostructures in aqueous solution at room temperature. The nanostructured films before and after ion exchange transformation reaction are characterized using field emission scanning electron microscope, energy dispersive X-ray analyzer, X-ray photoelectron spectroscopy, thin film X-ray diffraction technique, high resolution transmission electron microscope, and selected area electron diffraction analysis technique. After the ion exchange transformation of nanostructures, the film shows conversion from insulator to highly electrical conductive semimetallic characteristic. When used as a counter electrode in I3(-)/I(-) redox electrolyte based dye-sensitized solar cells, the telluride film exhibits an electrocatalytic reduction activity for I3(-) with a demonstration of solar-light to electrical power conversion efficiency of 8.10%, which is highly competitive to the efficiency of 8.20% exhibited by a benchmarked Pt-film counter electrode. On the other hand, the telluride film electrode also demonstrates electrocatalytic activity for oxygen evolution reaction from oxidation of water.

  6. Improved survival of patients with homozygous familial hypercholesterolaemia treated with plasma exchange.

    PubMed Central

    Thompson, G R; Miller, J P; Breslow, J L

    1985-01-01

    Plasma exchange was undertaken in five patients with homozygous familial hypercholesterolaemia at intervals of two weeks for a mean of 8.4 years. These patients had survived an average of 5.5 years longer than their five respective homozygous siblings (p = 0.3), each of whom must have had a matching genetic defect but who died untreated. The 37% decrease in peak serum cholesterol concentrations maintained by plasma exchange presumably reduced progression of atherosclerosis in the treated patients and thus lessened their risk of premature death. PMID:3935235

  7. Estimating the magnitude of annual peak discharges with recurrence intervals between 1.1 and 3.0 years for rural, unregulated streams in West Virginia

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Atkins, John T.; Newell, Dawn A.

    2002-01-01

    Multiple and simple least-squares regression models for the log10-transformed 1.5- and 2-year recurrence intervals of peak discharges with independent variables describing the basin characteristics (log10-transformed and untransformed) for 236 streamflow-gaging stations were evaluated, and the regression residuals were plotted as areal distributions that defined three regions in West Virginia designated as East, North, and South. Regional equations for the 1.1-, 1.2-, 1.3-, 1.4-, 1.5-, 1.6-, 1.7-, 1.8-, 1.9-, 2.0-, 2.5-, and 3-year recurrence intervals of peak discharges were determined by generalized least-squares regression. Log10-transformed drainage area was the most significant independent variable for all regions. Equations developed in this study are applicable only to rural, unregulated streams within the boundaries of West Virginia. The accuracies of estimating equations are quantified by measuring the average prediction error (from 27.4 to 52.4 percent) and equivalent years of record (from 1.1 to 3.4 years).

  8. Relativity and the TRS-80.

    ERIC Educational Resources Information Center

    Levin, Sidney

    1984-01-01

    Presents the listing (TRS-80) for a computer program which derives the relativistic equation (employing as a model the concept of a moving clock which emits photons at regular intervals) and calculates transformations of time, mass, and length with increasing velocities (Einstein-Lorentz transformations). (JN)

  9. Speciation of Cu and Zn during composting of pig manure amended with rock phosphate.

    PubMed

    Lu, Duian; Wang, Lixia; Yan, Baixing; Ou, Yang; Guan, Jiunian; Bian, Yu; Zhang, Yubin

    2014-08-01

    Pig manure usually contains a large amount of metals, especially Cu and Zn, which may limit its land application. Rock phosphate has been shown to be effective for immobilizing toxic metals in toxic metals contaminated soils. The aim of this study work was to investigate the effect of rock phosphate on the speciation of Cu and Zn during co-composting of pig manure with rice straw. The results showed that composting process and rock phosphate addition significantly affected the changes of metal species. During co-composting, the exchangeable and reducible fractions of Cu were transformed to organic and residue fractions, thus the bioavailable Cu fractions were decreased. The rock phosphate addition enhanced the metal transformation depending on the level of rock phosphate amendment. Zinc was found in the exchangeable and reducible fractions in the compost. The bioavailable Zn fraction changed a little during the composting process. The composting process converted the exchangeable Zn fraction into reducible fraction. Addition of an appropriate amount (5.0%) of rock phosphate could advance the conversion. Rock phosphate could reduce metal availability through adsorption and complexation of the metal ions on inorganic components. The increase in pH and organic matter degradation could be responsible for the reduction in exchangeable and bioavailable Cu fractions and exchangeable Zn fraction in rock phosphate amended compost. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Water masses transform at mid-depths over the Antarctic Continental Slope

    NASA Astrophysics Data System (ADS)

    Mead Silvester, Jess; Lenn, Yueng-Djern; Polton, Jeffrey; Phillips, Helen E.; Morales Maqueda, Miguel

    2017-04-01

    The Meridional Overturning Circulation (MOC) controls the oceans' latitudinal heat distribution, helping to regulate the Earth's climate. The Southern Ocean is the primary place where cool, deep waters return to the surface to complete this global circulation. While water mass transformations intrinsic to this process predominantly take place at the surface following upwelling, recent studies implicate vertical mixing in allowing transformation at mid-depths over the Antarctic continental slope. We deployed an EM-Apex float near Elephant Island, north of the Antarctic Peninsula's tip, to profile along the slope and use potential vorticity to diagnose observed instabilities. The float captures direct heat exchange between a lens of Upper Circumpolar Deep Water (UCDW) and surrounding Lower Circumpolar Deep Waters (LCDW) at mid-depths and over the course of several days. Heat fluxes peak across the top and bottom boundaries of the UCDW lens and peak diffusivities across the bottom boundary are associated with shear instability. Estimates of diffusivity from shear-strain finestructure parameterisation and heat fluxes are found to be in reasonable agreement. The two-dimensional Ertel potential vorticity is elevated both inside the UCDW lens and along its bottom boundary, with a strong contribution from the shear term in these regions and instabilities are associated with gravitational and symmetric forcing. Thus, shear instabilities are driving turbulent mixing across the lower boundary between these two water masses, leading to the observed heat exchange and transformation at mid-depths over the Antarctic continental slope. This has implications for our understanding of the rates of upwelling and ocean-atmosphere exchanges of heat and carbon at this critical location.

  11. Fast and nondestructive determination of protein content in rapeseeds (Brassica napus L.) using Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS).

    PubMed

    Lu, Yuzhen; Du, Changwen; Yu, Changbing; Zhou, Jianmin

    2014-08-01

    Fast and non-destructive determination of rapeseed protein content carries significant implications in rapeseed production. This study presented the first attempt of using Fourier transform mid-infrared photoacoustic spectroscopy (FTIR-PAS) to quantify protein content of rapeseed. The full-spectrum model was first built using partial least squares (PLS). Interval selection methods including interval partial least squares (iPLS), synergy interval partial least squares (siPLS), backward elimination interval partial least squares (biPLS) and dynamic backward elimination interval partial least squares (dyn-biPLS) were then employed to select the relevant band or band combination for PLS modeling. The full-spectrum PLS model achieved an ratio of prediction to deviation (RPD) of 2.047. In comparison, all interval selection methods produced better results than full-spectrum modeling. siPLS achieved the best predictive accuracy with an RPD of 3.215 when the spectrum was sectioned into 25 intervals, and two intervals (1198-1335 and 1614-1753 cm(-1) ) were selected. iPLS excelled biPLS and dyn-biPLS, and dyn-biPLS performed slightly better than biPLS. FTIR-PAS was verified as a promising analytical tool to quantify rapeseed protein content. Interval selection could extract the relevant individual band or synergy band associated with the sample constituent of interest, and then improve the prediction accuracy of the full-spectrum model. © 2013 Society of Chemical Industry.

  12. Security Enhancement of Wireless Sensor Networks Using Signal Intervals

    PubMed Central

    Moon, Jaegeun; Jung, Im Y.; Yoo, Jaesoo

    2017-01-01

    Various wireless technologies, such as RF, Bluetooth, and Zigbee, have been applied to sensor communications. However, the applications of Bluetooth-based wireless sensor networks (WSN) have a security issue. In one pairing process during Bluetooth communication, which is known as simple secure pairing (SSP), the devices are required to specify I/O capability or user interference to prevent man-in-the-middle (MITM) attacks. This study proposes an enhanced SSP in which a nonce to be transferred is converted to a corresponding signal interval. The quantization level, which is used to interpret physical signal intervals, is renewed at every connection by the transferred nonce and applied to the next nonce exchange so that the same signal intervals can represent different numbers. Even if attackers eavesdrop on the signals, they cannot understand what is being transferred because they cannot determine the quantization level. Furthermore, the proposed model does not require exchanging passkeys as data, and the devices are secure in the case of using a fixed PIN. Subsequently, the new quantization level is calculated automatically whenever the same devices attempt to connect with each other. Therefore, the pairing process can be protected from MITM attacks and be convenient for users. PMID:28368341

  13. Security Enhancement of Wireless Sensor Networks Using Signal Intervals.

    PubMed

    Moon, Jaegeun; Jung, Im Y; Yoo, Jaesoo

    2017-04-02

    Various wireless technologies, such as RF, Bluetooth, and Zigbee, have been applied to sensor communications. However, the applications of Bluetooth-based wireless sensor networks (WSN) have a security issue. In one pairing process during Bluetooth communication, which is known as simple secure pairing (SSP), the devices are required to specify I/O capability or user interference to prevent man-in-the-middle (MITM) attacks. This study proposes an enhanced SSP in which a nonce to be transferred is converted to a corresponding signal interval. The quantization level, which is used to interpret physical signal intervals, is renewed at every connection by the transferred nonce and applied to the next nonce exchange so that the same signal intervals can represent different numbers. Even if attackers eavesdrop on the signals, they cannot understand what is being transferred because they cannot determine the quantization level. Furthermore, the proposed model does not require exchanging passkeys as data, and the devices are secure in the case of using a fixed PIN. Subsequently, the new quantization level is calculated automatically whenever the same devices attempt to connect with each other. Therefore, the pairing process can be protected from MITM attacks and be convenient for users.

  14. An appraisal of statistical procedures used in derivation of reference intervals.

    PubMed

    Ichihara, Kiyoshi; Boyd, James C

    2010-11-01

    When conducting studies to derive reference intervals (RIs), various statistical procedures are commonly applied at each step, from the planning stages to final computation of RIs. Determination of the necessary sample size is an important consideration, and evaluation of at least 400 individuals in each subgroup has been recommended to establish reliable common RIs in multicenter studies. Multiple regression analysis allows identification of the most important factors contributing to variation in test results, while accounting for possible confounding relationships among these factors. Of the various approaches proposed for judging the necessity of partitioning reference values, nested analysis of variance (ANOVA) is the likely method of choice owing to its ability to handle multiple groups and being able to adjust for multiple factors. Box-Cox power transformation often has been used to transform data to a Gaussian distribution for parametric computation of RIs. However, this transformation occasionally fails. Therefore, the non-parametric method based on determination of the 2.5 and 97.5 percentiles following sorting of the data, has been recommended for general use. The performance of the Box-Cox transformation can be improved by introducing an additional parameter representing the origin of transformation. In simulations, the confidence intervals (CIs) of reference limits (RLs) calculated by the parametric method were narrower than those calculated by the non-parametric approach. However, the margin of difference was rather small owing to additional variability in parametrically-determined RLs introduced by estimation of parameters for the Box-Cox transformation. The parametric calculation method may have an advantage over the non-parametric method in allowing identification and exclusion of extreme values during RI computation.

  15. [Transformation of Cu forms in Cynodon dactylon rhizosphere soil of copper tailings yard].

    PubMed

    Wang, You-bao; Huang, Yong-jie; Zhen, Quan; Yan, Mi; Yang, Hong-fei; Liu, Deng-yi

    2007-06-01

    The study on the Cu forms in Cynodon dactylon rhizosphere soil of copper tailings yard in Tongling City, Anhui Province showed that among the test Cu forms, the amount of residual form occupied the majority, while that of exchangeable form was relatively low. Compared with non-rhizosphere soil, rhizosphere soil had a higher organic matter content but a lower pH. With the growth of C. dactylon, the contents of organically combined and exchangeable Cu in rhizosphere soil increased by 7.89% and 5%, respectively, while those of carbonate-combined and Fe-Mn oxides-combined Cu decreased. The growth of C. dactylon accelerated the transformation of Cu forms in rhizosphere soil, and decreased the rhizosphere soil Cu content through its absorption.

  16. Single-site trinuclear copper oxygen clusters in mordenite for selective conversion of methane to methanol

    DOE PAGES

    Grundner, Sebastian; Markovits, Monica A. C.; Li, Guanna; ...

    2015-06-25

    Copper-exchanged zeolites with mordenite structure mimic the nuclearity and reactivity of active sites in particulate methane monooxygenase, which are enzymes able to selectively oxidize methane to methanol. Here we show that the mordenite micropores provide a perfect confined environment for the highly selective stabilization of trinuclear copper-oxo clusters that exhibit a high reactivity towards activation of carbon–hydrogen bonds in methane and its subsequent transformation to methanol. In conclusion, the similarity with the enzymatic systems is also implied from the similarity of the reversible rearrangements of the trinuclear clusters occurring during the selective transformations of methane along the reaction path towardsmore » methanol, in both the enzyme system and copper-exchanged mordenite.« less

  17. Single-site trinuclear copper oxygen clusters in mordenite for selective conversion of methane to methanol

    PubMed Central

    Grundner, Sebastian; Markovits, Monica A.C.; Li, Guanna; Tromp, Moniek; Pidko, Evgeny A.; Hensen, Emiel J.M.; Jentys, Andreas; Sanchez-Sanchez, Maricruz; Lercher, Johannes A.

    2015-01-01

    Copper-exchanged zeolites with mordenite structure mimic the nuclearity and reactivity of active sites in particulate methane monooxygenase, which are enzymes able to selectively oxidize methane to methanol. Here we show that the mordenite micropores provide a perfect confined environment for the highly selective stabilization of trinuclear copper-oxo clusters that exhibit a high reactivity towards activation of carbon–hydrogen bonds in methane and its subsequent transformation to methanol. The similarity with the enzymatic systems is also implied from the similarity of the reversible rearrangements of the trinuclear clusters occurring during the selective transformations of methane along the reaction path towards methanol, in both the enzyme system and copper-exchanged mordenite. PMID:26109507

  18. Observation of High Transformer Ratio of Shaped Bunch Generated by an Emittance-Exchange Beam Line.

    PubMed

    Gao, Q; Ha, G; Jing, C; Antipov, S P; Power, J G; Conde, M; Gai, W; Chen, H; Shi, J; Wisniewski, E E; Doran, D S; Liu, W; Whiteford, C E; Zholents, A; Piot, P; Baturin, S S

    2018-03-16

    Collinear wakefield acceleration has been long established as a method capable of generating ultrahigh acceleration gradients. Because of the success on this front, recently, more efforts have shifted towards developing methods to raise the transformer ratio (TR). This figure of merit is defined as the ratio of the peak acceleration field behind the drive bunch to the peak deceleration field inside the drive bunch. TR is always less than 2 for temporally symmetric drive bunch distributions and therefore recent efforts have focused on generating asymmetric distributions to overcome this limitation. In this Letter, we report on using the emittance-exchange method to generate a shaped drive bunch to experimentally demonstrate a TR≈5 in a dielectric wakefield accelerator.

  19. Possibility of transforming the electronic structure of one species of graphene adatoms into that of another by application of gate voltage: First-principles calculations

    NASA Astrophysics Data System (ADS)

    Chan, Kevin T.; Lee, Hoonkyung; Cohen, Marvin L.

    2011-10-01

    Graphene provides many advantages for controlling the electronic structure of adatoms and other adsorbates via gating. Using the projected density of states and charge density obtained from first-principles density-functional periodic supercell calculations, we investigate the possibility of performing “alchemy” of adatoms on graphene, i.e., transforming the electronic structure of one species of adatom into that of another species by application of a gate voltage. Gating is modeled as a change in the number of electrons in the unit cell, with the inclusion of a compensating uniform background charge. Within this model and the generalized gradient approximation to the exchange-correlation functional, we find that such transformations are possible for K, Ca, and several transition-metal adatoms. Gate control of the occupation of the p states of In on graphene is also investigated. The validity of the supercell approximation with uniform compensating charge and the model for exchange and correlation is also discussed.

  20. Synthesis and Ion-Exchange Properties of Graphene Th(IV) Phosphate Composite Cation Exchanger: Its Applications in the Selective Separation of Lead Metal Ions

    PubMed Central

    Rangreez, Tauseef Ahmad; Alhogbi, Basma G.; Naushad, Mu.

    2017-01-01

    In this study, graphene Th(IV) phosphate was prepared by sol–gel precipitation method. The ion-exchange behavior of this cation-exchanger was studied by investigating properties like ion-exchange capacity for various metal ions, the effect of eluent concentration, elution behavior, and thermal effect on ion-exchange capacity (IEC). Several physicochemical properties as Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) study, thermal studies, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies were also carried out. The material possessed an IEC of 1.56 meq·dry·g−1 of the exchanger and was found to be nano-composite. The selectivity studies showed that the material is selective towards Pb(II) ions. The selectivity of this cation-exchanger was demonstrated in the binary separation of Pb(II) ions from mixture with other metal ions. The recovery was found to be both quantitative and reproducible. PMID:28737717

  1. On ``Overestimation-free Computational Version of Interval Analysis''

    NASA Astrophysics Data System (ADS)

    Popova, Evgenija D.

    2013-10-01

    The transformation of interval parameters into trigonometric functions, proposed in Int. J. Comput. Meth. Eng. Sci. Mech., vol. 13, pp. 319-328 (2012), is not motivated in comparison to the infinitely many equivalent algebraic transformations. The conclusions about the efficacy of the methodology used are based on incorrect comparisons between solutions of different problems. We show theoretically, and in the examples considered in the commented article, that changing the number of the parameters in a system of linear algebraic equations may change the initial problem, respectively, its solution set. We also correct various misunderstandings and bugs that appear in the article noted above.

  2. Monte Carlo-based interval transformation analysis for multi-criteria decision analysis of groundwater management strategies under uncertain naphthalene concentrations and health risks

    NASA Astrophysics Data System (ADS)

    Ren, Lixia; He, Li; Lu, Hongwei; Chen, Yizhong

    2016-08-01

    A new Monte Carlo-based interval transformation analysis (MCITA) is used in this study for multi-criteria decision analysis (MCDA) of naphthalene-contaminated groundwater management strategies. The analysis can be conducted when input data such as total cost, contaminant concentration and health risk are represented as intervals. Compared to traditional MCDA methods, MCITA-MCDA has the advantages of (1) dealing with inexactness of input data represented as intervals, (2) mitigating computational time due to the introduction of Monte Carlo sampling method, (3) identifying the most desirable management strategies under data uncertainty. A real-world case study is employed to demonstrate the performance of this method. A set of inexact management alternatives are considered in each duration on the basis of four criteria. Results indicated that the most desirable management strategy lied in action 15 for the 5-year, action 8 for the 10-year, action 12 for the 15-year, and action 2 for the 20-year management.

  3. 40 CFR 796.3500 - Hydrolysis as a function of pH at 25 °C.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Transformation Processes § 796...) in water in which the X group is lost. These reactions generally follow the same type of rate laws... elements of water (H2O). This type of transformation often results in the net exchange of a group X, on an...

  4. Steerable dyadic wavelet transform and interval wavelets for enhancement of digital mammography

    NASA Astrophysics Data System (ADS)

    Laine, Andrew F.; Koren, Iztok; Yang, Wuhai; Taylor, Fred J.

    1995-04-01

    This paper describes two approaches for accomplishing interactive feature analysis by overcomplete multiresolution representations. We show quantitatively that transform coefficients, modified by an adaptive non-linear operator, can make more obvious unseen or barely seen features of mammography without requiring additional radiation. Our results are compared with traditional image enhancement techniques by measuring the local contrast of known mammographic features. We design a filter bank representing a steerable dyadic wavelet transform that can be used for multiresolution analysis along arbitrary orientations. Digital mammograms are enhanced by orientation analysis performed by a steerable dyadic wavelet transform. Arbitrary regions of interest (ROI) are enhanced by Deslauriers-Dubuc interpolation representations on an interval. We demonstrate that our methods can provide radiologists with an interactive capability to support localized processing of selected (suspicion) areas (lesions). Features extracted from multiscale representations can provide an adaptive mechanism for accomplishing local contrast enhancement. By improving the visualization of breast pathology can improve changes of early detection while requiring less time to evaluate mammograms for most patients.

  5. Evaluation of statistical models for forecast errors from the HBV model

    NASA Astrophysics Data System (ADS)

    Engeland, Kolbjørn; Renard, Benjamin; Steinsland, Ingelin; Kolberg, Sjur

    2010-04-01

    SummaryThree statistical models for the forecast errors for inflow into the Langvatn reservoir in Northern Norway have been constructed and tested according to the agreement between (i) the forecast distribution and the observations and (ii) median values of the forecast distribution and the observations. For the first model observed and forecasted inflows were transformed by the Box-Cox transformation before a first order auto-regressive model was constructed for the forecast errors. The parameters were conditioned on weather classes. In the second model the Normal Quantile Transformation (NQT) was applied on observed and forecasted inflows before a similar first order auto-regressive model was constructed for the forecast errors. For the third model positive and negative errors were modeled separately. The errors were first NQT-transformed before conditioning the mean error values on climate, forecasted inflow and yesterday's error. To test the three models we applied three criterions: we wanted (a) the forecast distribution to be reliable; (b) the forecast intervals to be narrow; (c) the median values of the forecast distribution to be close to the observed values. Models 1 and 2 gave almost identical results. The median values improved the forecast with Nash-Sutcliffe R eff increasing from 0.77 for the original forecast to 0.87 for the corrected forecasts. Models 1 and 2 over-estimated the forecast intervals but gave the narrowest intervals. Their main drawback was that the distributions are less reliable than Model 3. For Model 3 the median values did not fit well since the auto-correlation was not accounted for. Since Model 3 did not benefit from the potential variance reduction that lies in bias estimation and removal it gave on average wider forecasts intervals than the two other models. At the same time Model 3 on average slightly under-estimated the forecast intervals, probably explained by the use of average measures to evaluate the fit.

  6. Registering coherent change detection products associated with large image sets and long capture intervals

    DOEpatents

    Perkins, David Nikolaus; Gonzales, Antonio I

    2014-04-08

    A set of co-registered coherent change detection (CCD) products is produced from a set of temporally separated synthetic aperture radar (SAR) images of a target scene. A plurality of transformations are determined, which transformations are respectively for transforming a plurality of the SAR images to a predetermined image coordinate system. The transformations are used to create, from a set of CCD products produced from the set of SAR images, a corresponding set of co-registered CCD products.

  7. Preparation of zeolite-A/chitosan hybrid composites and their bioactivities and antimicrobial activities.

    PubMed

    Yu, Liang; Gong, Jie; Zeng, Changfeng; Zhang, Lixiong

    2013-10-01

    Zeolite-A/chitosan hybrid composites with zeolite contents of 20-55 wt.% were prepared by in situ transformation of silica/chitosan mixtures in a sodium aluminate alkaline solution through impregnation-gelation-hydrothermal synthesis. The products were characterized by X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mercury penetration porosimetry. Their in vitro bioactivities were examined using as-synthesized and Ca(2+)-exchanged hybrid composites in simulated body fluid (SBF) for hydroxyapatite (HAP) growth. Their antimicrobial activities for Escherichia coli (E. coli) in trypticase soy broth (TSB) were evaluated using Ag(+)-exchanged hybrid composites. The zeolite-A/chitosan hybrid composites could be prepared as various shapes, including cylinders, plates and thin films. They possessed macropores with pore sizes ranging from 100 to 300 μm and showed compressive mechanical strength as high as 3.2 MPa when the zeolite content was 35 wt.%. Fast growth on the Ca(2+)-exchanged hybrid composites was observed with the highest weight gain of 51.4% in 30 days. The 35 wt.% Ag(+)-exchanged hybrid composite showed the highest antimicrobial activity, which could reduce the 9×10(6) CFU mL(-1)E. coli concentration to zero within 4h of incubation time with the Ag(+)-exchanged hybrid composite amount of 0.4 g L(-1). The bioactivity and antimicrobial activity could be combined by ion-exchanging the composites first with Ca(2+) and then with Ag(+). These zeolite-A/chitosan hybrid composites have potential applications on tissue engineering and antimicrobial food packaging. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Impaired Gas Exchange at Birth and Risk of Intellectual Disability and Autism: A Meta-Analysis

    ERIC Educational Resources Information Center

    Modabbernia, Amirhossein; Mollon, Josephine; Boffetta, Paolo; Reichenberg, Abraham

    2016-01-01

    We conducted meta-analyses of 67 studies on the association between neonatal proxies of impaired gas exchange and intellectual disability (ID) or autism spectrum disorders (ASD). Neonatal acidosis was associated with an odds ratio (OR) of 3.55 [95% confidence interval (95% CI) 2.23-5.49] for ID and an OR of 1.10 (95% CI 0.91-1.31) for ASD.…

  9. Particle Models with Self Sustained Current

    NASA Astrophysics Data System (ADS)

    Colangeli, M.; De Masi, A.; Presutti, E.

    2017-06-01

    We present some computer simulations run on a stochastic cellular automaton (CA). The CA simulates a gas of particles which are in a channel,the interval [1, L] in Z, but also in "reservoirs" R_1 and R_2. The evolution in the channel simulates a lattice gas with Kawasaki dynamics with attractive Kac interactions; the temperature is chosen smaller than the mean field critical one. There are also exchanges of particles between the channel and the reservoirs and among reservoirs. When the rate of exchanges among reservoirs is in a suitable interval the CA reaches an apparently stationary state with a non zero current; for different choices of the initial condition the current changes sign. We have a quite satisfactory theory of the phenomenon but we miss a full mathematical proof.

  10. Influence of harvesting on biogeochemical exchange in sheetflow and soil processes in a eutrophic floodplain forest

    Treesearch

    B.G. Lockaby; R.G. Clawson; K. Flynn; Robert Rummer; S. Meadows; B Stokes; John A. Stanturf

    1997-01-01

    Floodplain forests contribute to the maintenance of water quality as a result of various biogeochemical transformations which occur within them. In particular, they can serve as sinks for nutrient run-off from adjacent uplands or as nutrient transformers as water moves downstream. However, little is known about the potential that land management activities may have for...

  11. 7 CFR 1726.14 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... electric system, e.g., a substation transformer, heat exchanger or a transmission structure. Force account... which is combined with equipment to form an electric system, e.g., poles, insulators, or conductors...

  12. 7 CFR 1726.14 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... electric system, e.g., a substation transformer, heat exchanger or a transmission structure. Force account... which is combined with equipment to form an electric system, e.g., poles, insulators, or conductors...

  13. 7 CFR 1726.14 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... electric system, e.g., a substation transformer, heat exchanger or a transmission structure. Force account... which is combined with equipment to form an electric system, e.g., poles, insulators, or conductors...

  14. 7 CFR 1726.14 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... electric system, e.g., a substation transformer, heat exchanger or a transmission structure. Force account... which is combined with equipment to form an electric system, e.g., poles, insulators, or conductors...

  15. 7 CFR 1726.14 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... electric system, e.g., a substation transformer, heat exchanger or a transmission structure. Force account... which is combined with equipment to form an electric system, e.g., poles, insulators, or conductors...

  16. Interaction of ammonium with birnessite: Evidence of a chemical and structural transformation in alkaline aqueous medium

    NASA Astrophysics Data System (ADS)

    Boumaiza, Hella; Coustel, Romain; Despas, Christelle; Ruby, Christian; Bergaoui, Latifa

    2018-02-01

    The ammonium cation interaction with Na-birnessite in aqueous alkaline medium was studied. Solution and solid analysis give evidence that birnessite is not only acting as a cationic exchanger toward NH4+. The surface analysis performed by XPS showed that N1s spectra are characterized by the existence of two different environments: one assignable to an interlayer NH4+ and the second to a chemisorbed N-species. Structural and chemical transformations were observed on birnessite with nitrogen mass balance deficit. The monitoring of NH4+, Na+, Mn2+, NO3- and NO2- and solid changes (average oxidation state of Mn, cation exchange capacity, solid nitrogen content and symmetry evolution identified by XRD and FTIR) indicate unambiguously that NH4+ reacts chemically with the birnessite.

  17. Leadership in applied psychology: Three waves of theory and research.

    PubMed

    Lord, Robert G; Day, David V; Zaccaro, Stephen J; Avolio, Bruce J; Eagly, Alice H

    2017-03-01

    Although in the early years of the Journal leadership research was rare and focused primarily on traits differentiating leaders from nonleaders, subsequent to World War II the research area developed in 3 major waves of conceptual, empirical, and methodological advances: (a) behavioral and attitude research; (b) behavioral, social-cognitive, and contingency research; and (c) transformational, social exchange, team, and gender-related research. Our review of this work shows dramatic increases in sophistication from early research focusing on personnel issues associated with World War I to contemporary multilevel models and meta-analyses on teams, shared leadership, leader-member exchange, gender, ethical, abusive, charismatic, and transformational leadership. Yet, many of the themes that characterize contemporary leadership research were also present in earlier research. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. Semilocal Exchange Energy Functional for Two-Dimensional Quantum Systems: A Step Beyond Generalized Gradient Approximations.

    PubMed

    Jana, Subrata; Samal, Prasanjit

    2017-06-29

    Semilocal density functionals for the exchange-correlation energy of electrons are extensively used as they produce realistic and accurate results for finite and extended systems. The choice of techniques plays a crucial role in constructing such functionals of improved accuracy and efficiency. An accurate and efficient semilocal exchange energy functional in two dimensions is constructed by making use of the corresponding hole which is derived based on the density matrix expansion. The exchange hole involved is localized under the generalized coordinate transformation and satisfies all the relevant constraints. Comprehensive testing and excellent performance of the functional is demonstrated versus exact exchange results. The accuracy of results obtained by using the newly constructed functional is quite remarkable as it substantially reduces the errors present in the local and nonempirical exchange functionals proposed so far for two-dimensional quantum systems. The underlying principles involved in the functional construction are physically appealing and hold promise for developing range separated and nonlocal exchange functionals in two dimensions.

  19. Transformation of self-assembled InAs/InP quantum dots into quantum rings without capping.

    PubMed

    Sormunen, Jaakko; Riikonen, Juha; Mattila, Marco; Tiilikainen, Jouni; Sopanen, Markku; Lipsanen, Harri

    2005-08-01

    Transformation of self-assembled InAs quantum dots (QDs) on InP(100) into quantum rings (QRs) is studied. In contrast to the typical approach to III--V semiconductor QR growth, the QDs are not capped to form rings. Atomic force micrographs reveal a drastic change from InAs QDs into rings after a growth interruption in tertiarybutylphosphine ambient. Strain energy relief in the InAs QD is discussed and a mechanism for dot-to-ring transformation by As/P exchange reactions is proposed.

  20. Reference interval computation: which method (not) to choose?

    PubMed

    Pavlov, Igor Y; Wilson, Andrew R; Delgado, Julio C

    2012-07-11

    When different methods are applied to reference interval (RI) calculation the results can sometimes be substantially different, especially for small reference groups. If there are no reliable RI data available, there is no way to confirm which method generates results closest to the true RI. We randomly drawn samples obtained from a public database for 33 markers. For each sample, RIs were calculated by bootstrapping, parametric, and Box-Cox transformed parametric methods. Results were compared to the values of the population RI. For approximately half of the 33 markers, results of all 3 methods were within 3% of the true reference value. For other markers, parametric results were either unavailable or deviated considerably from the true values. The transformed parametric method was more accurate than bootstrapping for sample size of 60, very close to bootstrapping for sample size 120, but in some cases unavailable. We recommend against using parametric calculations to determine RIs. The transformed parametric method utilizing Box-Cox transformation would be preferable way of RI calculation, if it satisfies normality test. If not, the bootstrapping is always available, and is almost as accurate and precise as the transformed parametric method. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Small-angle neutron scattering study of magnetic ordering and inhomogeneity across the martensitic phase transformation in Ni 50–xCo xMn₄₀Sn₁₀ alloys

    DOE PAGES

    Bhatti, Kanwal Preet; El-Khatib, S.; Srivastava, Vijay; ...

    2012-04-27

    The Heusler-derived multiferroic alloy Ni 50–xCo xMn₄₀Sn₁₀ has recently been shown to exhibit, at just above room temperature, a highly reversible martensitic phase transformation with an unusually large magnetization change. In this work the nature of the magnetic ordering above and below this transformation has been studied in detail in the critical composition range x = 6–8 via temperature-dependent (5–600 K) magnetometry and small-angle neutron scattering (SANS). We observe fairly typical paramagnetic to long-range-ordered ferromagnetic phase transitions on cooling to 420–430 K, with the expected critical spin fluctuations, followed by first-order martensitic phase transformations to a nonferromagnetic state below 360–390more » K. The static magnetization reveals complex magnetism in this low-temperature nonferromagnetic phase, including a Langevin-like field dependence, distinct spin freezing near 60 K, and significant exchange bias effects, consistent with superparamagnetic blocking of ferromagnetic clusters of nanoscopic dimensions. We demonstrate that these spin clusters, whose existence has been hypothesized in a variety of martensitic alloys exhibiting competition between ferromagnetic and antiferromagnetic exchange interactions, can be directly observed by SANS. The scattering data are consistent with a liquidlike spatial distribution of interacting magnetic clusters with a mean center-to-center spacing of 12 nm. Considering the behavior of the superparmagnetism, cooling-field and temperature-dependent exchange bias, and magnetic SANS, we discuss in detail the physical form and origin of these spin clusters, their intercluster interactions, the nature of the ground-state magnetic ordering in the martensitic phase, and the implications for our understanding of such alloy systems.« less

  2. Deblurring for spatial and temporal varying motion with optical computing

    NASA Astrophysics Data System (ADS)

    Xiao, Xiao; Xue, Dongfeng; Hui, Zhao

    2016-05-01

    A way to estimate and remove spatially and temporally varying motion blur is proposed, which is based on an optical computing system. The translation and rotation motion can be independently estimated from the joint transform correlator (JTC) system without iterative optimization. The inspiration comes from the fact that the JTC system is immune to rotation motion in a Cartesian coordinate system. The work scheme of the JTC system is designed to keep switching between the Cartesian coordinate system and polar coordinate system in different time intervals with the ping-pang handover. In the ping interval, the JTC system works in the Cartesian coordinate system to obtain a translation motion vector with optical computing speed. In the pang interval, the JTC system works in the polar coordinate system. The rotation motion is transformed to the translation motion through coordinate transformation. Then the rotation motion vector can also be obtained from JTC instantaneously. To deal with continuous spatially variant motion blur, submotion vectors based on the projective motion path blur model are proposed. The submotion vectors model is more effective and accurate at modeling spatially variant motion blur than conventional methods. The simulation and real experiment results demonstrate its overall effectiveness.

  3. Synthesis of ion-exchange resin for selective thorium and uranyl ions sorption

    NASA Astrophysics Data System (ADS)

    Konovalov, Konstantin; Sachkov, Victor

    2017-11-01

    In this work, the method of ion-exchange resin synthesis selective to radionuclides (uranium and thorium) is presented. The method includes synthesis of polymeric styrene-divinylbenzene macroporous matrix with size of 0.1-0.2 mm, and its subsequent transformation by nitration and then reduction by tin (II) chloride. For passivation of active primary amines partially oxidation by oxygen from air is used. Obtained ion-exchange resin has ratio of sorption sum U+Th to sorption sum of other total rare-earth elements as 1:1.88 at ratio of solid to liquid phase 1:200. The proposed method of ion-exchange resin synthesis is scaled-up for laboratory reactors with volume of 5 and 50 liters.

  4. Fluctuations in time intervals of financial data from the view point of the Gini index

    NASA Astrophysics Data System (ADS)

    Sazuka, Naoya; Inoue, Jun-ichi

    2007-09-01

    We propose an approach to explain fluctuations in time intervals of financial markets data from the view-point of the Gini index. We show the explicit form of the Gini index for a Weibull distribution: A good candidate to describe the first passage time of foreign exchange rate. The analytical expression of the Gini index compares well with the value obtained from empirical data.

  5. Confidence intervals for the first crossing point of two hazard functions.

    PubMed

    Cheng, Ming-Yen; Qiu, Peihua; Tan, Xianming; Tu, Dongsheng

    2009-12-01

    The phenomenon of crossing hazard rates is common in clinical trials with time to event endpoints. Many methods have been proposed for testing equality of hazard functions against a crossing hazards alternative. However, there has been relatively few approaches available in the literature for point or interval estimation of the crossing time point. The problem of constructing confidence intervals for the first crossing time point of two hazard functions is considered in this paper. After reviewing a recent procedure based on Cox proportional hazard modeling with Box-Cox transformation of the time to event, a nonparametric procedure using the kernel smoothing estimate of the hazard ratio is proposed. The proposed procedure and the one based on Cox proportional hazard modeling with Box-Cox transformation of the time to event are both evaluated by Monte-Carlo simulations and applied to two clinical trial datasets.

  6. Transformation of temporal sequences in the zebra finch auditory system

    PubMed Central

    Lim, Yoonseob; Lagoy, Ryan; Shinn-Cunningham, Barbara G; Gardner, Timothy J

    2016-01-01

    This study examines how temporally patterned stimuli are transformed as they propagate from primary to secondary zones in the thalamorecipient auditory pallium in zebra finches. Using a new class of synthetic click stimuli, we find a robust mapping from temporal sequences in the primary zone to distinct population vectors in secondary auditory areas. We tested whether songbirds could discriminate synthetic click sequences in an operant setup and found that a robust behavioral discrimination is present for click sequences composed of intervals ranging from 11 ms to 40 ms, but breaks down for stimuli composed of longer inter-click intervals. This work suggests that the analog of the songbird auditory cortex transforms temporal patterns to sequence-selective population responses or ‘spatial codes', and that these distinct population responses contribute to behavioral discrimination of temporally complex sounds. DOI: http://dx.doi.org/10.7554/eLife.18205.001 PMID:27897971

  7. Swinger RNAs with sharp switches between regular transcription and transcription systematically exchanging ribonucleotides: Case studies.

    PubMed

    Seligmann, Hervé

    2015-09-01

    During RNA transcription, DNA nucleotides A,C,G, T are usually matched by ribonucleotides A, C, G and U. However occasionally, this rule does not apply: transcript-DNA homologies are detectable only assuming systematic exchanges between ribonucleotides. Nine symmetric (X ↔ Y, e.g. A ↔ C) and fourteen asymmetric (X ↔ Y ↔ Z, e.g. A ↔ C ↔ G) exchanges exist, called swinger transcriptions. Putatively, polymerases occasionally stabilize in unspecified swinger conformations, possibly similar to transient conformations causing punctual misinsertions. This predicts chimeric transcripts, part regular, part swinger-transformed, reflecting polymerases switching to swinger polymerization conformation(s). Four chimeric Genbank transcripts (three from human mitochondrion and one murine cytosolic) are described here: (a) the 5' and 3' extremities reflect regular polymerization, the intervening sequence exchanges systematically between ribonucleotides (swinger rule G ↔ U, transcript (1), with sharp switches between regular and swinger sequences; (b) the 5' half is 'normal', the 3' half systematically exchanges ribonucleotides (swinger rule C ↔ G, transcript (2), with an intercalated sequence lacking homology; (c) the 3' extremity fits A ↔ G exchanges (10% of transcript length), the 5' half follows regular transcription; the intervening region seems a mix of regular and A ↔ G transcriptions (transcript 3); (d) murine cytosolic transcript 4 switches to A ↔ U + C ↔ G, and is fused with A ↔ U + C ↔ G swinger transformed precursor rRNA. In (c), each concomitant transcript 5' and 3' extremities match opposite genome strands. Transcripts 3 and 4 combine transcript fusions with partial swinger transcriptions. Occasional (usually sharp) switches between regular and swinger transcriptions reveal greater coding potential than detected until now, suggest stable polymerase swinger conformations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  8. Predicting Protein Aggregation during Storage in Lyophilized Solids Using Solid State Amide Hydrogen/Deuterium Exchange with Mass Spectrometric Analysis (ssHDX-MS)

    PubMed Central

    2015-01-01

    Solid state amide hydrogen/deuterium exchange with mass spectrometric analysis (ssHDX-MS) was used to assess the conformation of myoglobin (Mb) in lyophilized formulations, and the results correlated with the extent of aggregation during storage. Mb was colyophilized with sucrose (1:1 or 1:8 w/w), mannitol (1:1 w/w), or NaCl (1:1 w/w) or in the absence of excipients. Immediately after lyophilization, samples of each formulation were analyzed by ssHDX-MS and Fourier transform infrared spectroscopy (FTIR) to assess Mb conformation, and by dynamic light scattering (DLS) and size exclusion chromatography (SEC) to determine the extent of aggregation. The remaining samples were then placed on stability at 25 °C and 60% RH or 40 °C and 75% RH for up to 1 year, withdrawn at intervals, and analyzed for aggregate content by SEC and DLS. In ssHDX-MS of samples immediately after lyophilization (t = 0), Mb was less deuterated in solids containing sucrose (1:1 and 1:8 w/w) than in those containing mannitol (1:1 w/w), NaCl (1:1 w/w), or Mb alone. Deuterium uptake kinetics and peptide mass envelopes also indicated greater Mb structural perturbation in mannitol, NaCl, or Mb-alone samples at t = 0. The extent of deuterium incorporation and kinetic parameters related to rapidly and slowly exchanging amide pools (Nfast, Nslow), measured at t = 0, were highly correlated with the extent of aggregation on storage as measured by SEC. In contrast, the extent of aggregation was weakly correlated with FTIR band intensity and peak position measured at t = 0. The results support the use of ssHDX-MS as a formulation screening tool in developing lyophilized protein drug products. PMID:24816133

  9. Return volatility interval analysis of stock indexes during a financial crash

    NASA Astrophysics Data System (ADS)

    Li, Wei-Shen; Liaw, Sy-Sang

    2015-09-01

    We investigate the interval between return volatilities above a certain threshold q for 10 countries data sets during the 2008/2009 global financial crisis, and divide these data into several stages according to stock price tendencies: plunging stage (stage 1), fluctuating or rebounding stage (stage 2) and soaring stage (stage 3). For different thresholds q, the cumulative distribution function always satisfies a power law tail distribution. We find the absolute value of the power-law exponent is lowest in stage 1 for various types of markets, and increases monotonically from stage 1 to stage 3 in emerging markets. The fractal dimension properties of the return volatility interval series provide some surprising results. We find that developed markets have strong persistence and transform to weaker correlation in the plunging and soaring stages. In contrast, emerging markets fail to exhibit such a transformation, but rather show a constant-correlation behavior with the recurrence of extreme return volatility in corresponding stages during a crash. We believe this long-memory property found in recurrence-interval series, especially for developed markets, plays an important role in volatility clustering.

  10. User's manual for SEDCALC, a computer program for computation of suspended-sediment discharge

    USGS Publications Warehouse

    Koltun, G.F.; Gray, John R.; McElhone, T.J.

    1994-01-01

    Sediment-Record Calculations (SEDCALC), a menu-driven set of interactive computer programs, was developed to facilitate computation of suspended-sediment records. The programs comprising SEDCALC were developed independently in several District offices of the U.S. Geological Survey (USGS) to minimize the intensive labor associated with various aspects of sediment-record computations. SEDCALC operates on suspended-sediment-concentration data stored in American Standard Code for Information Interchange (ASCII) files in a predefined card-image format. Program options within SEDCALC can be used to assist in creating and editing the card-image files, as well as to reformat card-image files to and from formats used by the USGS Water-Quality System. SEDCALC provides options for creating card-image files containing time series of equal-interval suspended-sediment concentrations from 1. digitized suspended-sediment-concentration traces, 2. linear interpolation between log-transformed instantaneous suspended-sediment-concentration data stored at unequal time intervals, and 3. nonlinear interpolation between log-transformed instantaneous suspended-sediment-concentration data stored at unequal time intervals. Suspended-sediment discharge can be computed from the streamflow and suspended-sediment-concentration data or by application of transport relations derived by regressing log-transformed instantaneous streamflows on log-transformed instantaneous suspended-sediment concentrations or discharges. The computed suspended-sediment discharge data are stored in card-image files that can be either directly imported to the USGS Automated Data Processing System or used to generate plots by means of other SEDCALC options.

  11. Iron(II)-Catalyzed Iron Atom Exchange and Mineralogical Changes in Iron-rich Organic Freshwater Flocs: An Iron Isotope Tracer Study.

    PubMed

    ThomasArrigo, Laurel K; Mikutta, Christian; Byrne, James; Kappler, Andreas; Kretzschmar, Ruben

    2017-06-20

    In freshwater wetlands, organic flocs are often found enriched in trace metal(loid)s associated with poorly crystalline Fe(III)-(oxyhydr)oxides. Under reducing conditions, flocs may become exposed to aqueous Fe(II), triggering Fe(II)-catalyzed mineral transformations and trace metal(loid) release. In this study, pure ferrihydrite, a synthetic ferrihydrite-polygalacturonic acid coprecipitate (16.7 wt % C), and As- (1280 and 1230 mg/kg) and organic matter (OM)-rich (18.1 and 21.8 wt % C) freshwater flocs dominated by ferrihydrite and nanocrystalline lepidocrocite were reacted with an isotopically enriched 57 Fe(II) solution (0.1 or 1.0 mM Fe(II)) at pH 5.5 and 7. Using a combination of wet chemistry, Fe isotope analysis, X-ray absorption spectroscopy (XAS), 57 Fe Mössbauer spectroscopy and X-ray diffraction, we followed the Fe atom exchange kinetics and secondary mineral formation over 1 week. When reacted with Fe(II) at pH 7, pure ferrihydrite exhibited rapid Fe atom exchange at both Fe(II) concentrations, reaching 76 and 89% atom exchange in experiments with 0.1 and 1 mM Fe(II), respectively. XAS data revealed that it transformed into goethite (21%) at the lower Fe(II) concentration and into lepidocrocite (73%) and goethite (27%) at the higher Fe(II) concentration. Despite smaller Fe mineral particles in the coprecipitate and flocs as compared to pure ferrihydrite (inferred from Mössbauer-derived blocking temperatures), these samples showed reduced Fe atom exchange (9-30% at pH 7) and inhibited secondary mineral formation. No release of As was recorded for Fe(II)-reacted flocs. Our findings indicate that carbohydrate-rich OM in flocs stabilizes poorly crystalline Fe minerals against Fe(II)-catalyzed transformation by surface-site blockage and/or organic Fe(II) complexation. This hinders the extent of Fe atom exchange at mineral surfaces and secondary mineral formation, which may consequently impair Fe(II)-activated trace metal(loid) release. Thus, under short-term Fe(III)-reducing conditions facilitating the fast attainment of solid-solution equilibria (e.g., in stagnant waters), Fe-rich freshwater flocs are expected to remain an effective sink for trace elements.

  12. All-inorganic Germanium nanocrystal films by cationic ligand exchange

    DOE PAGES

    Wheeler, Lance M.; Nichols, Asa W.; Chernomordik, Boris D.; ...

    2016-01-21

    In this study, we introduce a new paradigm for group IV nanocrystal surface chemistry based on room temperature surface activation that enables ionic ligand exchange. Germanium nanocrystals synthesized in a gas-phase plasma reactor are functionalized with labile, cationic alkylammonium ligands rather than with traditional covalently bound groups. We employ Fourier transform infrared and 1H nuclear magnetic resonance spectroscopies to demonstrate the alkylammonium ligands are freely exchanged on the germanium nanocrystal surface with a variety of cationic ligands, including short inorganic ligands such as ammonium and alkali metal cations. This ionic ligand exchange chemistry is used to demonstrate enhanced transport inmore » germanium nanocrystal films following ligand exchange as well as the first photovoltaic device based on an all-inorganic germanium nanocrystal absorber layer cast from solution. This new ligand chemistry should accelerate progress in utilizing germanium and other group IV nanocrystals for optoelectronic applications.« less

  13. The development of the cell cryopreservation protocol with controlled rate thawing.

    PubMed

    Gurina, Tatyana M; Pakhomov, Alexandr V; Polyakova, Anna L; Legach, Evgeniy I; Bozhok, Galyna A

    2016-06-01

    Thawing in the water bath is often considered as a standard procedure. The thermal history of samples thawed in this way is poorly controlled, but cryopreservation and banking of cell-based products require standardization, automation and safety of all the technological stages including thawing. The programmable freezers allow implementation of the controlled cooling as well as the controlled thawing. As the cell damage occurs during the phase transformation that takes place in the cryoprotectant medium in the process of freezing-thawing, the choice of warming rates within the temperature intervals of transformations is very important. The goal of the study was to investigate the influence of warming rates within the intervals of the phase transformations in the DMSO-based cryoprotectant medium on the cell recovery and to develop a cryopreservation protocol with controlled cooling and warming rates. The temperature intervals of phase transformations such as melting of the eutectic mixture of the cryoprotectant solution (MEMCS), melting of the eutectic salt solution (MESS), melting of the main ice mass (MMIM), recrystallization before MEMCS, recrystallization before MESS and recrystallization before MMIM were determined by thermo-mechanical analysis. The biological experiments were performed on the rat testicular interstitial cells (TIC). The highest levels of the cell recovery and metabolic activity after cryopreservation were obtained using the protocol with the high (20 °C/min) warming rate in the temperature intervals of crystallization of the eutectics as well as recrystallizations and the low (1 °C/min) warming rate in the temperature intervals of melting of the eutectics as well as MMIM. The total cell recovery was 65.3 ± 2.1 %, the recovery of the 3-beta-HSD-positive (Leydig) cells was 82.9 ± 1.8 %, the MTT staining was 32.5 ± 0.9 % versus 42.1 ± 1.7 %; 57.4 ± 2.1 % and 24.0 ± 1.1 % respectively, when compared to the thawing in the water bath.

  14. Management of endoscopic biliary stenting for choledocholithiasis: Evaluation of stent-exchange intervals.

    PubMed

    Tohda, Gen; Dochin, Masaki

    2018-01-16

    To evaluate the best management of plastic stents in patients with choledocholithiasis who were unfit for endoscopic stone removal or surgery. Between April 2007 and September 2017, 87 patients (median age 83.7 years) with symptomatic choledocholithiasis were treated with insertion of 7-Fr plastic stents because complete endoscopic stone retrieval was difficult, and their general condition was not suitable for surgery. Seventy of these patients agreed to regular stent management and stent exchange was carried out at every 6 mo (Group A, n = 35) or every 12 mo (Group B, n = 35). The remaining 17 patients did not accept regular stent exchange, and stents were replaced when clinical symptoms appeared (Group C). We evaluated the frequency of biliary complication and stent patency rate during follow-up periods. The patency rate of biliary plastic stents was 91.4% at 6 mo (Group A) and 88.6% at 12 mo (Group B), respectively. Acute cholangitis occurred in 2.9% of Group A patients and in 8.6% of Group B patients. In Group C, median stent patency was 16.3 mo, and stent exchange was carried out in 70.6% of cases because of acute cholangitis or obstructive jaundice. Although a high incidence of acute cholangitis occurred, there was no biliary-related mortality. Plastic stent exchange at 12-mo intervals is considered a safe procedure for patients with choledocholithiasis. Long-term biliary stenting increases biliary complications, but it can be an acceptable option for select patients who are medically unfit for further invasive procedures.

  15. Development and application of an exchange model for anisotropic water diffusion in the microporous MOF aluminum fumarate

    NASA Astrophysics Data System (ADS)

    Splith, Tobias; Fröhlich, Dominik; Henninger, Stefan K.; Stallmach, Frank

    2018-06-01

    Diffusion of water in aluminum fumarate was studied by means of pulsed field gradient (PFG) nuclear magnetic resonance (NMR). Due to water molecules exchanging between the intracrystalline anisotropic pore space and the isotropic intercrystalline void space the model of intracrystalline anisotropic diffusion fails to describe the experimental PFG NMR data at high observation times. Therefore, the two-site exchange model developed by Kärger is extended to the case of exchange between an anisotropic and an isotropic site. This extended exchange model is solved by numerical integration. It describes the experimental data very well and yields values for the intracrystalline diffusion coefficient and the mean residence times of the respective sites. Further PFG NMR studies were performed with coatings consisting of small aluminum fumarate crystals, which are used in adsorptive heat transformation applications. The diffusion coefficients of water in the small crystal coating are compared to the values expected from the extended two-site exchange model and from the model of long-range diffusion.

  16. Transforming Classroom Music Instruction with Ideas from Critical Pedagogy: Teachers and Students Can Learn from Each Other when They Use Lesson Plans that Encourage an Exchange of Knowledge

    ERIC Educational Resources Information Center

    Abrahams, Frank

    2005-01-01

    Paulo Freire developed critical pedagogy in Brazil in the 1960s to teach illiterate adults (or, as Freire calls them, "the oppressed") to read. Freire believed that teaching was a conversational exchange of information between the teacher and the student. He posed questions and problems to his students that caused them to take what they already…

  17. The Transformation from Defence Procurement to Defence Acquisition - Opportunities for New Forms of Analytical Support

    DTIC Science & Technology

    2010-04-01

    Exchanges of Services ( ATARES ); Strategic Airlift Interim Solution (SALIS); Strategic Airlift Capability (SAC); the European Air Transport Fleet (EATF... ATARES is a TA, established in order to facilitate the exchange of military capabilities based on equivalent flying hours with Lockheed C-130 Hercules...initiatives such as NATO PfP, EU BG, MNE, NAMSA, MCCE, ATARES , SALIS, and SAC. The participation in the EU BG concept was as one of the contributors

  18. Exchangeable cations-mediated photodegradation of polycyclic aromatic hydrocarbons (PAHs) on smectite surface under visible light.

    PubMed

    Jia, Hanzhong; Li, Li; Chen, Hongxia; Zhao, Yue; Li, Xiyou; Wang, Chuanyi

    2015-04-28

    Clay minerals saturated with different exchangeable cations are expected to play various roles in photodegradation of polycyclic aromatic hydrocarbons (PAHs) via direct and/or indirect pathways on clay surfaces. In the present study, anthracene and phenanthrene were selected as molecule probes to investigate the roles of exchangeable cations on their photodegradation under visible light irradiation. For five types of cation-modified smectite clays, the photodegradation rate of anthracene and phenanthrene follows the order: Fe(3+)>Al(3+)>Cu(2+)>Ca(2+)>K(+)>Na(+), which is consistent with the binding energy of cation-π interactions between PAHs and exchangeable cations. The result suggests that PAHs photolysis rate depends on cation-π interactions on clay surfaces. Meanwhile, the deposition of anthracene at the Na(+)-smectite and K(+)-smectite surface favors solar light absorption, resulting in enhanced direct photodecomposition of PAHs. On the other hand, smectite clays saturated with Fe(3+), Al(3+), and Cu(2+) are highly photoreactive and can act as potential catalysts giving rise to oxidative radicals such as O2(-) , which initiate the transformation of PAHs. The present work provides valuable insights into understanding the transformation and fate of PAHs in the natural soil environment and sheds light on the development of technologies for contaminated land remediation. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Infrared maritime target detection using the high order statistic filtering in fractional Fourier domain

    NASA Astrophysics Data System (ADS)

    Zhou, Anran; Xie, Weixin; Pei, Jihong

    2018-06-01

    Accurate detection of maritime targets in infrared imagery under various sea clutter conditions is always a challenging task. The fractional Fourier transform (FRFT) is the extension of the Fourier transform in the fractional order, and has richer spatial-frequency information. By combining it with the high order statistic filtering, a new ship detection method is proposed. First, the proper range of angle parameter is determined to make it easier for the ship components and background to be separated. Second, a new high order statistic curve (HOSC) at each fractional frequency point is designed. It is proved that maximal peak interval in HOSC reflects the target information, while the points outside the interval reflect the background. And the value of HOSC relative to the ship is much bigger than that to the sea clutter. Then, search the curve's maximal target peak interval and extract the interval by bandpass filtering in fractional Fourier domain. The value outside the peak interval of HOSC decreases rapidly to 0, so the background is effectively suppressed. Finally, the detection result is obtained by the double threshold segmenting and the target region selection method. The results show the proposed method is excellent for maritime targets detection with high clutters.

  20. The efficiency of parameter estimation of latent path analysis using summated rating scale (SRS) and method of successive interval (MSI) for transformation of score to scale

    NASA Astrophysics Data System (ADS)

    Solimun, Fernandes, Adji Achmad Rinaldo; Arisoesilaningsih, Endang

    2017-12-01

    Research in various fields generally investigates systems and involves latent variables. One method to analyze the model representing the system is path analysis. The data of latent variables measured using questionnaires by applying attitude scale model yields data in the form of score, before analyzed should be transformation so that it becomes data of scale. Path coefficient, is parameter estimator, calculated from scale data using method of successive interval (MSI) and summated rating scale (SRS). In this research will be identifying which data transformation method is better. Path coefficients have smaller varieties are said to be more efficient. The transformation method that produces scaled data and used in path analysis capable of producing path coefficients (parameter estimators) with smaller varieties is said to be better. The result of analysis using real data shows that on the influence of Attitude variable to Intention Entrepreneurship, has relative efficiency (ER) = 1, where it shows that the result of analysis using data transformation of MSI and SRS as efficient. On the other hand, for simulation data, at high correlation between items (0.7-0.9), MSI method is more efficient 1.3 times better than SRS method.

  1. Empirical Investigation of Moderating and Mediating Variables in between Transformational Leadership and Related Outcomes: A Study of Higher Education Sector in North India

    ERIC Educational Resources Information Center

    Jyoti, Jeevan; Bhau, Sonia

    2016-01-01

    Purpose: The purpose of this paper is to evaluate the multi-layer effect of transformational leadership (TL) on employee-related outcomes, i.e. relational identification (RI) and satisfaction with leader (SWL). Further, role of leader member exchange (LMX) and the association period in between TL and RI as well as SWL shall also be examined. So,…

  2. On the design of recursive digital filters

    NASA Technical Reports Server (NTRS)

    Shenoi, K.; Narasimha, M. J.; Peterson, A. M.

    1976-01-01

    A change of variables is described which transforms the problem of designing a recursive digital filter to that of approximation by a ratio of polynomials on a finite interval. Some analytic techniques for the design of low-pass filters are presented, illustrating the use of the transformation. Also considered are methods for the design of phase equalizers.

  3. Transformation to equivalent dimensions—a new methodology to study earthquake clustering

    NASA Astrophysics Data System (ADS)

    Lasocki, Stanislaw

    2014-05-01

    A seismic event is represented by a point in a parameter space, quantified by the vector of parameter values. Studies of earthquake clustering involve considering distances between such points in multidimensional spaces. However, the metrics of earthquake parameters are different, hence the metric in a multidimensional parameter space cannot be readily defined. The present paper proposes a solution of this metric problem based on a concept of probabilistic equivalence of earthquake parameters. Under this concept the lengths of parameter intervals are equivalent if the probability for earthquakes to take values from either interval is the same. Earthquake clustering is studied in an equivalent rather than the original dimensions space, where the equivalent dimension (ED) of a parameter is its cumulative distribution function. All transformed parameters are of linear scale in [0, 1] interval and the distance between earthquakes represented by vectors in any ED space is Euclidean. The unknown, in general, cumulative distributions of earthquake parameters are estimated from earthquake catalogues by means of the model-free non-parametric kernel estimation method. Potential of the transformation to EDs is illustrated by two examples of use: to find hierarchically closest neighbours in time-space and to assess temporal variations of earthquake clustering in a specific 4-D phase space.

  4. Alternative Shapes and Shaping Techniques for Enhanced Transformer Ratios in Beam Driven Techniques

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lemery, F.; Piot, P.

    The transformer ration of collinear beam-driven techniques can be significantly improved by shaping the current profile of the drive bunch. To date, several current shapes have been proposed to increase the transformer ratio and produce quasi-uniform energy loss within the drive bunch. Some of these tailoring techniques are possible as a results of recent beam-dynamics advances, e.g., transverse-to-longitudinal emittance exchanger. In ths paper, we propose an alternative class of longitudinal shapes that enable high transformer ratio and uniform energy loss across the drive bunch. We also suggest a simple method based on photocathode-laser shaping and passive shaping in wakefield structuremore » to realize shape close to the theoretically optimized current profiles.« less

  5. Ionothermal synthesis and structural transformation targeted by ion exchange in metal-1,3,5-benzenetricarboxylate compounds

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xu, Qing-Qing; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002; Liu, Bing

    Ionothermal reactions of 1,3,5-benzenetricarboxylate acid (H{sub 3}BTC) and Ni(NO{sub 3}){sub 2}, Co(NO{sub 3}){sub 2} and Cu(NO{sub 3}){sub 2} gave two discrete 32-membered ring-like allomers, [M{sub 2}(HBTC){sub 2}(NH{sub 2}CONH{sub 2}){sub 2}(H{sub 2}O){sub 4}]·3H{sub 2}O (M=Ni(1), Co(2)) and one layered [Cu{sub 2}(BTC)Cl(H{sub 2}O){sub 4}] (3). The weak interactions in 1 can be deconstructed to some degree in ion exchange by exploring the factors of divalent and trivalent metal species, metal concentration and soaking time, which are demonstrated by PXRD and N{sub 2} absorption. Cu{sup 2+} has the highest N{sub 2} adsorbance when soaking with 1, and 1 can keep structure stable whenmore » Cu{sup 2+} below 0.16 mol L{sup −1} and the soaking time within 24d. As Cu{sup 2+} beyond 0.16 mol L{sup −1} and the soaking time beyond 24d, the structure of compound 1 starts to transform with the crystal morphology from clear pale green to opaque blue. Ionothermal reactions of compound 1 with different Cu{sup 2+} amounts obtained Ni{sup 2+}-Cu{sup 2+} hetero complexes, whose PXRD patterns are similar to that of 3 and EDS indicates Cu{sup 2+}% increases with Cu{sup 2+} additions and close to 100% as Cu{sup 2+} being 1.6 mmol. It suggests that 3 is a controlled product and Cu{sup 2+} can transform discrete compound 1 into 2D compound 3. - Graphical abstract: Three compounds were synthesized through ionothermal reactions. The weak interactions in compound 1 can be deconstructed by ion exchange and discrete compound 1 can be transformed into layered compound 3. - Highlights: • Two discrete ring-like and one layered compounds were ionothermally synthesized. • Metal species, metal concentration and soaking time deconstruct the H-bondings in 1. • 1 can be transformed to 3 through ionothermal reaction, otherwise forbidden.« less

  6. The Utilization of Network Enabled Capability in NATO Air C2 and Targeting Systems

    DTIC Science & Technology

    2013-06-01

    TBMCS Mission Exchange 3.1 ICC-JCOP JCOP aims to provide a common operational picture to the NATO users to increase the situational awareness by...transformation steps (Figure 9). Figure 9: WISI consumed by Oracle’s SOA tools 3.4 ICC-ACCS- TBMCS Mission Exchange The aim of this experiment was to... TBMCS ) using a common methodology. For this purpose, initially, a common mission definition (CMD) was defined which had the same meaning for all of

  7. Co-metal-organic-frameworks with pure uniform crystal morphology prepared via Co2 + exchange-mediated transformation from Zn-metallogels for luminol catalysed chemiluminescence

    NASA Astrophysics Data System (ADS)

    Tang, Xue Qian; Xiao, Bo Wen; Li, Chun Mei; Wang, Dong Mei; Huang, Cheng Zhi; Li, Yuan Fang

    2017-03-01

    Cation exchange-mediated transformation from Zn-metallogels (MOGs), which was a mild facile strategy relative to the demanding hydrothermal method, was employed to develop Co2 + metal-organic frameworks (Co-MOFs) at room temperature. The obtained Co-MOFs was of uniform octahedral morphology and possessed high activity to catalyze luminol chemiluminescence without extra oxidants. By adding cysteine, the CL emission of luminol-Co-MOFs system was further enhanced. Based on this phenomenon, Co-MOFs was utilized to build a practical sensing platform for cysteine determination. Under the optimized conditions, the relative CL intensity (ΔI) was proportional to the concentration of cysteine in the range of 2-10 μM, and the detection limit was 0.49 μM (3S/N). Moreover, the established method was applied to the determination of cysteine in commercially available pharmaceutical injections.

  8. Ground-state information geometry and quantum criticality in an inhomogeneous spin model

    NASA Astrophysics Data System (ADS)

    Ma, Yu-Quan

    2015-09-01

    We investigate the ground-state Riemannian metric and the cyclic quantum distance of an inhomogeneous quantum spin-1/2 chain in a transverse field. This model can be diagonalized by using a general canonical transformation to the fermionic Hamiltonian mapped from the spin system. The ground-state Riemannian metric is derived exactly on a parameter manifold ring S1, which is introduced by performing a gauge transformation to the spin Hamiltonian through a twist operator. The cyclic ground-state quantum distance and the second derivative of the ground-state energy are studied in different exchange coupling parameter regions. Particularly, we show that, in the case of exchange coupling parameter Ja = Jb, the quantum ferromagnetic phase can be characterized by an invariant quantum distance and this distance will decay to zero rapidly in the paramagnetic phase. Project supported by the National Natural Science Foundation of China (Grant Nos. 11404023 and 11347131).

  9. On importance assessment of aging multi-state system

    NASA Astrophysics Data System (ADS)

    Frenkel, Ilia; Khvatskin, Lev; Lisnianski, Anatoly

    2017-01-01

    Modern high-tech equipment requires precise temperature control and effective cooling below the ambient temperature. Greater cooling efficiencies will allow equipment to be operated for longer periods without overheating, providing a greater return on investment and increased in availability of the equipment. This paper presents application of the Lz-transform method to importance assessment of aging multi-state water-cooling system used in one of Israeli hospitals. The water cooling system consists of 3 principal sub-systems: chillers, heat exchanger and pumps. The performance of the system and the sub-systems is measured by their produced cooling capacity. Heat exchanger is an aging component. Straightforward Markov method applied to solve this problem will require building of a system model with numerous numbers of states and solving a corresponding system of multiple differential equations. Lz-transform method, which is used for calculation of the system elements importance, drastically simplified the solution. Numerical example is presented to illustrate the described approach.

  10. Morphological Pulmonary Diffusion Capacity for Oxygen of Burmese Pythons (Python molurus): a Comparison of Animals in Healthy Condition and with Different Pulmonary Infections.

    PubMed

    Starck, J M; Weimer, I; Aupperle, H; Müller, K; Marschang, R E; Kiefer, I; Pees, M

    2015-11-01

    A qualitative and quantitative morphological study of the pulmonary exchange capacity of healthy and diseased Burmese pythons (Python molurus) was carried out in order to test the hypothesis that the high morphological excess capacity for oxygen exchange in the lungs of these snakes is one of the reasons why pathological processes extend throughout the lung parenchyma and impair major parts of the lungs before clinical signs of respiratory disease become apparent. Twenty-four Burmese pythons (12 healthy and 12 diseased) were included in the study. A stereology-based approach was used to quantify the lung parenchyma using computed tomography. Light microscopy was used to quantify tissue compartments and the respiratory exchange surface, and transmission electron microscopy was used to measure the thickness of the diffusion barrier. The morphological diffusion capacity for oxygen of the lungs and the anatomical diffusion factor were calculated. The calculated anatomical diffusion capacity was compared with published values for oxygen consumption of healthy snakes, and the degree to which the exchange capacity can be obstructed before normal physiological function is impaired was estimated. Heterogeneous pulmonary infections result in graded morphological transformations of pulmonary parenchyma involving lymphocyte migration into the connective tissue and thickening of the septal connective tissue, increasing thickness of the diffusion barrier and increasing transformation of the pulmonary epithelium into a columnar pseudostratified or stratified epithelium. The transformed epithelium developed by hyperplasia of ciliated cells arising from the tip of the faveolar septa and by hyperplasia of type II pneumocytes. These results support the idea that the lungs have a remarkable overcapacity for oxygen consumption and that the development of pulmonary disease continuously reduces the capacity for oxygen consumption. However, due to the overcapacity of the lungs, this reduction does not result in clinical signs and disease can progress unrecognized for an extended period. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Cucheb: A GPU implementation of the filtered Lanczos procedure

    NASA Astrophysics Data System (ADS)

    Aurentz, Jared L.; Kalantzis, Vassilis; Saad, Yousef

    2017-11-01

    This paper describes the software package Cucheb, a GPU implementation of the filtered Lanczos procedure for the solution of large sparse symmetric eigenvalue problems. The filtered Lanczos procedure uses a carefully chosen polynomial spectral transformation to accelerate convergence of the Lanczos method when computing eigenvalues within a desired interval. This method has proven particularly effective for eigenvalue problems that arise in electronic structure calculations and density functional theory. We compare our implementation against an equivalent CPU implementation and show that using the GPU can reduce the computation time by more than a factor of 10. Program Summary Program title: Cucheb Program Files doi:http://dx.doi.org/10.17632/rjr9tzchmh.1 Licensing provisions: MIT Programming language: CUDA C/C++ Nature of problem: Electronic structure calculations require the computation of all eigenvalue-eigenvector pairs of a symmetric matrix that lie inside a user-defined real interval. Solution method: To compute all the eigenvalues within a given interval a polynomial spectral transformation is constructed that maps the desired eigenvalues of the original matrix to the exterior of the spectrum of the transformed matrix. The Lanczos method is then used to compute the desired eigenvectors of the transformed matrix, which are then used to recover the desired eigenvalues of the original matrix. The bulk of the operations are executed in parallel using a graphics processing unit (GPU). Runtime: Variable, depending on the number of eigenvalues sought and the size and sparsity of the matrix. Additional comments: Cucheb is compatible with CUDA Toolkit v7.0 or greater.

  12. Transformation of Chloroplast Ribosomal RNA Genes in Chlamydomonas: Molecular and Genetic Characterization of Integration Events

    PubMed Central

    Newman, S. M.; Boynton, J. E.; Gillham, N. W.; Randolph-Anderson, B. L.; Johnson, A. M.; Harris, E. H.

    1990-01-01

    Transformation of chloroplast ribosomal RNA (rRNA) genes in Chlamydomonas has been achieved by the biolistic process using cloned chloroplast DNA fragments carrying mutations that confer antibiotic resistance. The sites of exchange employed during the integration of the donor DNA into the recipient genome have been localized using a combination of antibiotic resistance mutations in the 16S and 23S rRNA genes and restriction fragment length polymorphisms that flank these genes. Complete or nearly complete replacement of a region of the chloroplast genome in the recipient cell by the corresponding sequence from the donor plasmid was the most common integration event. Exchange events between the homologous donor and recipient sequences occurred preferentially near the vector:insert junctions. Insertion of the donor rRNA genes and flanking sequences into one inverted repeat of the recipient genome was followed by intramolecular copy correction so that both copies of the inverted repeat acquired identical sequences. Increased frequencies of rRNA gene transformants were achieved by reducing the copy number of the chloroplast genome in the recipient cells and by decreasing the heterology between donor and recipient DNA sequences flanking the selectable markers. In addition to producing bona fide chloroplast rRNA transformants, the biolistic process induced mutants resistant to low levels of streptomycin, typical of nuclear mutations in Chlamydomonas. PMID:1981764

  13. A framework for interval-valued information system

    NASA Astrophysics Data System (ADS)

    Yin, Yunfei; Gong, Guanghong; Han, Liang

    2012-09-01

    Interval-valued information system is used to transform the conventional dataset into the interval-valued form. To conduct the interval-valued data mining, we conduct two investigations: (1) construct the interval-valued information system, and (2) conduct the interval-valued knowledge discovery. In constructing the interval-valued information system, we first make the paired attributes in the database discovered, and then, make them stored in the neighbour locations in a common database and regard them as 'one' new field. In conducting the interval-valued knowledge discovery, we utilise some related priori knowledge and regard the priori knowledge as the control objectives; and design an approximate closed-loop control mining system. On the implemented experimental platform (prototype), we conduct the corresponding experiments and compare the proposed algorithms with several typical algorithms, such as the Apriori algorithm, the FP-growth algorithm and the CLOSE+ algorithm. The experimental results show that the interval-valued information system method is more effective than the conventional algorithms in discovering interval-valued patterns.

  14. Color image enhancement based on particle swarm optimization with Gaussian mixture

    NASA Astrophysics Data System (ADS)

    Kattakkalil Subhashdas, Shibudas; Choi, Bong-Seok; Yoo, Ji-Hoon; Ha, Yeong-Ho

    2015-01-01

    This paper proposes a Gaussian mixture based image enhancement method which uses particle swarm optimization (PSO) to have an edge over other contemporary methods. The proposed method uses the guassian mixture model to model the lightness histogram of the input image in CIEL*a*b* space. The intersection points of the guassian components in the model are used to partition the lightness histogram. . The enhanced lightness image is generated by transforming the lightness value in each interval to appropriate output interval according to the transformation function that depends on PSO optimized parameters, weight and standard deviation of Gaussian component and cumulative distribution of the input histogram interval. In addition, chroma compensation is applied to the resulting image to reduce washout appearance. Experimental results show that the proposed method produces a better enhanced image compared to the traditional methods. Moreover, the enhanced image is free from several side effects such as washout appearance, information loss and gradation artifacts.

  15. The role of the Na+/Ca2+ exchanger, INa and ICaL in the genesis of dofetilide-induced torsades de pointes in isolated, AV-blocked rabbit hearts

    PubMed Central

    Farkas, Attila S; Makra, Péter; Csík, Norbert; Orosz, Szabolcs; Shattock, Michael J; Fülöp, Ferenc; Forster, Tamás; Csanády, Miklós; Papp, Julius Gy; Varró, András; Farkas, András

    2009-01-01

    Background and purpose: The Na+/Ca2+ exchanger (NCX) may contribute to triggered activity and transmural dispersion of repolarization, which are substrates of torsades de pointes (TdP) type arrhythmias. This study examined the effects of selective inhibition of the NCX by SEA0400 on the occurrence of dofetilide-induced TdP. Experimental approach: Effects of SEA0400 (1 µmol·L−1) on dofetilide-induced TdP was studied in isolated, Langendorff-perfused, atrioventricular (AV)-blocked rabbit hearts. To verify the relevance of the model, lidocaine (30 µmol·L−1) and verapamil (750 nmol·L−1) were also tested against dofetilide-induced TdP. Key results: Acute AV block caused a chaotic idioventricular rhythm and strikingly increased beat-to-beat variability of the RR and QT intervals. SEA0400 exaggerated the dofetilide-induced increase in the heart rate-corrected QT interval (QTc) and did not reduce the incidence of dofetilide-induced TdP [100% in the SEA0400 + dofetilide group vs. 75% in the dofetilide (100 nmol·L−1) control]. In the second set of experiments, verapamil further increased the dofetilide-induced QTc prolongation and neither verapamil nor lidocaine reduced the dofetilide-induced increase in the beat-to-beat variability of the QT interval. However, lidocaine decreased and verapamil prevented the development of dofetilide-induced TdP as compared with the dofetilide control (TdP incidence: 13%, 0% and 88% respectively). Conclusions and implications: Na+/Ca2+ exchanger does not contribute to dofetilide-induced TdP, whereas Na+ and Ca2+ channel activity is involved in TdP genesis in isolated, AV-blocked rabbit hearts. Neither QTc prolongation nor an increase in the beat-to-beat variability of the QT interval is a sufficient prerequisite of TdP genesis in rabbit hearts. PMID:19222480

  16. Novel transformation-based response prediction of shear building using interval neural network

    NASA Astrophysics Data System (ADS)

    Chakraverty, S.; Sahoo, Deepti Moyi

    2017-04-01

    Present paper uses powerful technique of interval neural network (INN) to simulate and estimate structural response of multi-storey shear buildings subject to earthquake motion. The INN is first trained for a real earthquake data, viz., the ground acceleration as input and the numerically generated responses of different floors of multi-storey buildings as output. Till date, no model exists to handle positive and negative data in the INN. As such here, the bipolar data in [ -1, 1] are converted first to unipolar form, i.e., to [0, 1] by means of a novel transformation for the first time to handle the above training patterns in normalized form. Once the training is done, again the unipolar data are converted back to its bipolar form by using the inverse transformation. The trained INN architecture is then used to simulate and test the structural response of different floors for various intensity earthquake data and it is found that the predicted responses given by INN model are good for practical purposes.

  17. Adsorption studies of heavy metal ions on mesoporous aluminosilicate, novel cation exchanger.

    PubMed

    Sepehrian, H; Ahmadi, S J; Waqif-Husain, S; Faghihian, H; Alighanbari, H

    2010-04-15

    Mesoporous aluminosilicates, have been prepared with various mole ratios of Si/Al and Cethyltrimethylammonium bromide (CTAB). They have been characterized by XRD, nitrogen adsorption/desorption measurements, FT-IR and thermogravimetry. Adsorption behavior of heavy metal ions on this adsorbent have been studied and discussed. The results show that incorporation of aluminum ions in the framework of the mesoporous MCM-41 has transformed it into an effective cation exchanger. The K(d) values of several metal ions have been increased. Separation of Sr(II)-Ce(III), Sr(II)-U(VI) and Cd(II)-Ce(III) has been developed on columns of this novel mesoporous cation exchanger. 2009 Elsevier B.V. All rights reserved.

  18. Probing peptide fragment ion structures by combining sustained off-resonance collision-induced dissociation and gas-phase H/D exchange (SORI-HDX) in Fourier transform ion-cyclotron resonance (FT-ICR) instruments.

    PubMed

    Somogyi, Arpád

    2008-12-01

    The usefulness of gas-phase H/D exchange is demonstrated to probe heterogeneous fragment and parent ion populations. Singly and multiply protonated peptides/proteins were fragmented by using sustained off-resonance irradiation collision-induced dissociation (SORI-CID). The fragments and the surviving precursor ions then all undergo H/D exchange in the gas-phase with either D(2)O or CD(3)OD under the same experimental conditions. Usually, 10 to 60 s of reaction time is adequate to monitor characteristic differences in the H/D exchange kinetic rates. These differences are then correlated to isomeric ion structures. The SORI-HDX method can be used to rapidly test fragment ion structures and provides useful insights into peptide fragmentation mechanisms.

  19. Assessing microbial utilization of free versus sorbed Alanine by using position-specific 13C labeling and 13C-PLFA analysis

    NASA Astrophysics Data System (ADS)

    Herschbach, Jennifer; Apostel, Carolin; Spielvogel, Sandra; Kuzyakov, Yakov; Dippold, Michaela

    2016-04-01

    Microbial utilization is a key transformation process of soil organic matter (SOM). Sorption of low molecular weight organic substances (LMWOS) to soil mineral surfaces blocks or delays microbial uptake and therefore mineralization of LMWOS to CO2, as well as all other biochemical transformations. We used position-specific labeling, a tool of isotope applications novel to soil science, combined with 13C-phospholipid fatty acid (PLFA) analysis, to assess microbial utilization of sorbed and non-sorbed Alanine in soil. Alanine has various functional groups enabling different sorption mechanisms via its positive charge (e.g. to clay minerals by cation exchange), as well as via its negative charge (e.g. to iron oxides by ligand exchange). To assess changes in the transformation pathways caused by sorption, we added uniformly and position-specifically 13C and 14C labeled Alanine to the Ap of a loamy Luvisol in a short-term (10 days) incubation experiment. To allow for sorption of the tracer solution to an aliquot of this soil, microbial activity was minimized in this subsample by sterilizing the soil by γ-radiation. After shaking, the remaining solutions were filtered and the non-sorbed Alanine was removed with Millipore water and then added to non-sterilized soil. For the free Alanine treatment, solutions with Alanine of similar amount and isotopic composition were prepared, added to the soil and incubated as well. The respired CO2 was trapped in NaOH and its 14C-activity was determined at increasing times intervals. Microbial utilization of Alanine's individual C positions was evaluated in distinct microbial groups classified by 13C-PLFA analysis. Sorption to soil minerals delayed respiration to CO2 and reduced initial respiration rate by 80%. Irrespective of sorption, the highest amount was respired from the carboxylic position (C-1), whereas the amino-bound (C-2) and the methylic position (C-3) were preferentially incorporated into PLFA of microorganisms due to the basic microbial metabolism of C3 molecules in glycolysis. Reconstruction of microbial transformation pathways showed that the C-2 position of Alanine was lost as CO2 faster than its C-3 position regardless of whether the molecule was used ana- or catabolically. The highest incorporations of all positions in PLFA were accomplished by Gram negatives. Free Alanine was preferentially used by highly competitive prokaryotes, while sorbed Alanine was preferred by filamentous microorganisms. In detail, the free living osmotrophic Gram negative bacteria utilize more easily accessible dissolved substances. The utilization of sorbed substances are achieved by less mobile microorganisms, e.g. eukaryotic fungi and Actinomycetes, which form biofilms. None of these findings could have been achieved without the position-specific labeling approach, therefore this method will strongly improve our understanding of stabilization processes and soil C fluxes.

  20. Dynamical analysis of the avian-human influenza epidemic model using the semi-analytical method

    NASA Astrophysics Data System (ADS)

    Jabbari, Azizeh; Kheiri, Hossein; Bekir, Ahmet

    2015-03-01

    In this work, we present a dynamic behavior of the avian-human influenza epidemic model by using efficient computational algorithm, namely the multistage differential transform method(MsDTM). The MsDTM is used here as an algorithm for approximating the solutions of the avian-human influenza epidemic model in a sequence of time intervals. In order to show the efficiency of the method, the obtained numerical results are compared with the fourth-order Runge-Kutta method (RK4M) and differential transform method(DTM) solutions. It is shown that the MsDTM has the advantage of giving an analytical form of the solution within each time interval which is not possible in purely numerical techniques like RK4M.

  1. Developing semi-analytical solution for multiple-zone transient storage model with spatially non-uniform storage

    NASA Astrophysics Data System (ADS)

    Deng, Baoqing; Si, Yinbing; Wang, Jia

    2017-12-01

    Transient storages may vary along the stream due to stream hydraulic conditions and the characteristics of storage. Analytical solutions of transient storage models in literature didn't cover the spatially non-uniform storage. A novel integral transform strategy is presented that simultaneously performs integral transforms to the concentrations in the stream and in storage zones by using the single set of eigenfunctions derived from the advection-diffusion equation of the stream. The semi-analytical solution of the multiple-zone transient storage model with the spatially non-uniform storage is obtained by applying the generalized integral transform technique to all partial differential equations in the multiple-zone transient storage model. The derived semi-analytical solution is validated against the field data in literature. Good agreement between the computed data and the field data is obtained. Some illustrative examples are formulated to demonstrate the applications of the present solution. It is shown that solute transport can be greatly affected by the variation of mass exchange coefficient and the ratio of cross-sectional areas. When the ratio of cross-sectional areas is big or the mass exchange coefficient is small, more reaches are recommended to calibrate the parameter.

  2. Gaussian beam profile shaping apparatus, method therefor and evaluation thereof

    DOEpatents

    Dickey, Fred M.; Holswade, Scott C.; Romero, Louis A.

    1999-01-01

    A method and apparatus maps a Gaussian beam into a beam with a uniform irradiance profile by exploiting the Fourier transform properties of lenses. A phase element imparts a design phase onto an input beam and the output optical field from a lens is then the Fourier transform of the input beam and the phase function from the phase element. The phase element is selected in accordance with a dimensionless parameter which is dependent upon the radius of the incoming beam, the desired spot shape, the focal length of the lens and the wavelength of the input beam. This dimensionless parameter can also be used to evaluate the quality of a system. In order to control the radius of the incoming beam, optics such as a telescope can be employed. The size of the target spot and the focal length can be altered by exchanging the transform lens, but the dimensionless parameter will remain the same. The quality of the system, and hence the value of the dimensionless parameter, can be altered by exchanging the phase element. The dimensionless parameter provides design guidance, system evaluation, and indication as to how to improve a given system.

  3. Gaussian beam profile shaping apparatus, method therefore and evaluation thereof

    DOEpatents

    Dickey, F.M.; Holswade, S.C.; Romero, L.A.

    1999-01-26

    A method and apparatus maps a Gaussian beam into a beam with a uniform irradiance profile by exploiting the Fourier transform properties of lenses. A phase element imparts a design phase onto an input beam and the output optical field from a lens is then the Fourier transform of the input beam and the phase function from the phase element. The phase element is selected in accordance with a dimensionless parameter which is dependent upon the radius of the incoming beam, the desired spot shape, the focal length of the lens and the wavelength of the input beam. This dimensionless parameter can also be used to evaluate the quality of a system. In order to control the radius of the incoming beam, optics such as a telescope can be employed. The size of the target spot and the focal length can be altered by exchanging the transform lens, but the dimensionless parameter will remain the same. The quality of the system, and hence the value of the dimensionless parameter, can be altered by exchanging the phase element. The dimensionless parameter provides design guidance, system evaluation, and indication as to how to improve a given system. 27 figs.

  4. Relationship between cutoff frequency and accuracy in time-interval photon statistics applied to oscillating signals

    NASA Astrophysics Data System (ADS)

    Rebolledo, M. A.; Martinez-Betorz, J. A.

    1989-04-01

    In this paper the accuracy in the determination of the period of an oscillating signal, when obtained from the photon statistics time-interval probability, is studied as a function of the precision (the inverse of the cutoff frequency of the photon counting system) with which time intervals are measured. The results are obtained by means of an experiment with a square-wave signal, where the Fourier or square-wave transforms of the time-interval probability are measured. It is found that for values of the frequency of the signal near the cutoff frequency the errors in the period are small.

  5. Global rates of mantle serpentinization and H2 release at oceanic transform faults

    NASA Astrophysics Data System (ADS)

    Ruepke, Lars; Hasenclever, Joerg

    2017-04-01

    The cycling of seawater through the ocean floor is the dominant mechanism of biogeochemical exchange between the solid earth and the global ocean. Crustal fluid flow appears to be typically associated with major seafloor structures, and oceanic transform faults (OTF) are one of the most striking yet poorly understood features of the global mid-ocean ridge systems. Fracture zones and transform faults have long been hypothesized to be sites of substantial biogeochemical exchange between the solid Earth and the global ocean. This is particularly interesting with regard to the ocean biome. Deep ocean ecosystems constitute 60% of it but their role in global ocean biogeochemical cycles is much overlooked. There is growing evidence that life is supported by chemosynthesis at hydrothermal vents but also in the crust, and therefore this may be a more abundant process than previously thought. In this context, the serpentine forming interaction between seawater and cold lithospheric mantle rocks is particularly interesting as it is also a mechanism of abiotic hydrogen and methane formation. Interestingly, a quantitative global assessment of mantle serpentinization at oceanic transform faults in the context of the biogeochemical exchange between the seafloor and the global ocean is still largely missing. Here we present the results of a set of 3-D thermo-mechanical model calculations that investigate mantle serpentinization at OTFs for the entire range of globally observed slip rates and fault lengths. These visco-plastic models predict the OTF thermal structure and the location of crustal-scale brittle deformation, which is a prerequisite for mantle serpentinization to occur. The results of these simulations are integrated with information on the global distribution of OTF lengths and slip rates yielding global estimates on mantle serpentinization and associated H2 release. We find that OTFs are potentially sites of intense crustal fluid flow and are in terms of H2 release almost as important as MOR-related serpentinization.

  6. Adaptive wavelet collocation methods for initial value boundary problems of nonlinear PDE's

    NASA Technical Reports Server (NTRS)

    Cai, Wei; Wang, Jian-Zhong

    1993-01-01

    We have designed a cubic spline wavelet decomposition for the Sobolev space H(sup 2)(sub 0)(I) where I is a bounded interval. Based on a special 'point-wise orthogonality' of the wavelet basis functions, a fast Discrete Wavelet Transform (DWT) is constructed. This DWT transform will map discrete samples of a function to its wavelet expansion coefficients in O(N log N) operations. Using this transform, we propose a collocation method for the initial value boundary problem of nonlinear PDE's. Then, we test the efficiency of the DWT transform and apply the collocation method to solve linear and nonlinear PDE's.

  7. Relationship of Chromosome Changes to Neoplastic Cell Transformation

    PubMed Central

    DiPaolo, Joseph A.; Popescu, Nicolae C.

    1976-01-01

    Chromosomal abnormalities are a frequent concomitant of neoplasia, and although it is tempting to relate these mutations and alterations in chromatin (DNA) function to cancer, their relationship to the initiation or progression of carcinogenesis is unknown. Mammalian cells in culture, after interacting with chemical carcinogens, often exhibit chromosome damage consisting of breaks and exchanges of chromatid material. The pattern of damage of banded metaphases indicates that negative bands are especially vulnerable to the action of chemical carcinogens, probably because of differential chromatin condensation. Damage to individual chromosomes may be random or nonrandom, depending on the species. Cell death can be correlated with chromatid alterations that occur shortly after treatment with chemical carcinogens. There is also a correlation between mutagenic and carcinogenic activity of some chemical carcinogens and the frequency of sister chromatid exchanges. The question of whether specific chromosome changes are absolutely required for neoplastic transformation cannot be answered because of conflicting data and diverse results from studies even with known carcinogens. Cell transformation may occur without any visible chromosome changes. A universal specific numerical or visible structural chromosomal alteration is not necessarily associated with chemical or viral transformation. Chromosome changes are independent of the etiologic agents: different carcinogens may produce transformation associated with the same abnormal chromosomes, but not all transformed lines invariably exhibit the same abnormality, even with the same chemical. In some species, chromosome having nucleolar organizer regions may be more frequently involved in numerical or structural deviations. Progressively growing tumors also may occur as a result of the proliferation of transformed cells without detectable chromosome changes, indicating that tumorigenicity need not be related to an imbalance of chromosome number or structure. Our studies indicate that chromosome changes are not essential for establishment of neoplasms but that karyotypic instability may result in response to selective growth pressures. ImagesFigure 2Figure 11Figure 3Figure 12Figure 4Figure 5Figure 6Figure 7Figure 8Figure 9Figure 1Figure 10 PMID:826168

  8. Activation of the Lbc Rho Exchange Factor Proto-Oncogene by Truncation of an Extended C Terminus That Regulates Transformation and Targeting

    PubMed Central

    Sterpetti, Paola; Hack, Andrew A.; Bashar, Mariam P.; Park, Brian; Cheng, Sou-De; Knoll, Joan H. M.; Urano, Takeshi; Feig, Larry A.; Toksoz, Deniz

    1999-01-01

    The human lbc oncogene product is a guanine nucleotide exchange factor that specifically activates the Rho small GTP binding protein, thus resulting in biologically active, GTP-bound Rho, which in turn mediates actin cytoskeletal reorganization, gene transcription, and entry into the mitotic S phase. In order to elucidate the mechanism of onco-Lbc transformation, here we report that while proto- and onco-lbc cDNAs encode identical N-terminal dbl oncogene homology (DH) and pleckstrin homology (PH) domains, proto-Lbc encodes a novel C terminus absent in the oncoprotein that includes a predicted α-helical region homologous to cyto-matrix proteins, followed by a proline-rich region. The lbc proto-oncogene maps to chromosome 15, and onco-lbc represents a fusion of the lbc proto-oncogene N terminus with a short, unrelated C-terminal sequence from chromosome 7. Both onco- and proto-Lbc can promote formation of GTP-bound Rho in vivo. Proto-Lbc transforming activity is much reduced compared to that of onco-Lbc, and a significant increase in transforming activity requires truncation of both the α-helical and proline-rich regions in the proto-Lbc C terminus. Deletion of the chromosome 7-derived C terminus of onco-Lbc does not destroy transforming activity, demonstrating that it is loss of the proto-Lbc C terminus, rather than gain of an unrelated C-terminus by onco-Lbc, that confers transforming activity. Mutations of onco-Lbc DH and PH domains demonstrate that both domains are necessary for full transforming activity. The proto-Lbc product localizes to the particulate (membrane) fraction, while the majority of the onco-Lbc product is cytosolic, and mutations of the PH domain do not affect this localization. The proto-Lbc C-terminus alone localizes predominantly to the particulate fraction, indicating that the C terminus may play a major role in the correct subcellular localization of proto-Lbc, thus providing a mechanism for regulating Lbc oncogenic potential. PMID:9891067

  9. Wind-driven variations in an overturning circulation

    NASA Astrophysics Data System (ADS)

    Bringedal, Carina; Eldevik, Tor; Spall, Michael

    2017-04-01

    The Atlantic overturning circulation and poleward heat transport is balanced by northern heat loss to the atmosphere and corresponding water mass transformation. The structure of this circulation and transformation is particularly manifested - and observed - at the Greenland-Scotland ridge. There is however a rich variability in the exchanges across the ridge on seasonal and yearly time scales. This variability has been almost perfectly captured in atmospherically forced ocean GCMs (e.g. Olsen et al 2008, Sandø et al 2012), suggesting that on shorter time scales the variability of the exchanges are connected to sea level pressure and corresponding wind stress forcing. Focusing on seasonal and yearly time scales, we accordingly propose that the connection between the exchanges of overturning waters across the Greenland-Scotland ridge and the sea level pressure must be direct and simple, and we use idealized simulations to support this hypothesis. The mechanisms underlying the connection are formulated through conceptual models. Although the models and simulations are simplified with respect to bathymetry and hydrography, they can reproduce the main features of the overturning circulation in the Nordic seas. In the observations, the variable exchanges can largely be related to sea level pressure variations and large scale wind patterns, and the idealized simulations and accompanying conceptual models show how these impacts can manifest via coastal downwelling and gyre circulation. S. M. Olsen, B. Hansen, D. Quadfasel and S. Østerhus, Observed and modelled stability of overflow across the Greenland-Scotland ridge, Nature 455, (2008) A. B. Sandø, J. E. Ø. Nilsen, T. Eldevik and M. Bentsen, Mechanisms for variable North Atlantic-Nordic seas exchanges, Journal of Geophysical Research 117, (2012)

  10. Effect of ionophores on the rate of intramolecular cation exchange in durosemiquinone ion pairs

    NASA Technical Reports Server (NTRS)

    Eastman, M. P.; Bruno, G. V.; Mcguyer, C. A.; Gutierrez, A. R.; Shannon, J. M.

    1979-01-01

    The effects of the ionophores 15-crown-5 (15C5), 18-crown-6 (18C6), dibenzo-18-crown-6 (DBC) and cryptand 222 (C222) on intramolecular cation exchange in ion pairs of the sodium salt of the durosemiquinone anion in benzene solution are investigated. Electron paramagnetic resonance spectra of the 18C6 and 15C5 complexes with durosemiquinone reduced by contact with a sodium mirror show an alternating line width which indicates that the sodium ion is being exchanged between equivalent sites near the oxygens of the semiquinone with activation energies of 8.7 and 6.0 kcal/mole and Arrhenius preexponential factors of 9 x 10 to the 12th/sec and 10 to the 12th/sec, respectively. Spectra obtained for the DBC complexes show no evidence of exchange, while those of C222 indicate rapid exchange. It is also noted that the hyperfine splitting constants measured do not change over the 50-K temperature interval studied.

  11. Measurement of the Exchange Rate of Waters of Hydration in Elastin by 2D T(2)-T(2) Correlation Nuclear Magnetic Resonance Spectroscopy.

    PubMed

    Sun, Cheng; Boutis, Gregory S

    2011-02-28

    We report on the direct measurement of the exchange rate of waters of hydration in elastin by T(2)-T(2) exchange spectroscopy. The exchange rates in bovine nuchal ligament elastin and aortic elastin at temperatures near, below and at the physiological temperature are reported. Using an Inverse Laplace Transform (ILT) algorithm, we are able to identify four components in the relaxation times. While three of the components are in good agreement with previous measurements that used multi-exponential fitting, the ILT algorithm distinguishes a fourth component having relaxation times close to that of free water and is identified as water between fibers. With the aid of scanning electron microscopy, a model is proposed allowing for the application of a two-site exchange analysis between any two components for the determination of exchange rates between reservoirs. The results of the measurements support a model (described elsewhere [1]) wherein the net entropy of bulk waters of hydration should increase upon increasing temperature in the inverse temperature transition.

  12. Quantitative analysis of seasonal variation in the amino acids in phloem sap of Salix alba L.

    PubMed

    Leckstein, P M; Llewellyn, M

    1975-01-01

    Phloem sap of Salix alba L. was collected at monthly intervals between May and October. Amino acid analysis was carried out by ion exchange chromatography. The concentrations of individual amino acids are reported.

  13. 76 FR 25390 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... calculates the CBOE Gold ETF Volatility Index (``GVZ''), which is based on the VIX methodology applied to options on the SPDR Gold Trust (``GLD''). The current filing would permit $0.50 strike price intervals for...

  14. Efficient Calculation of Exact Exchange Within the Quantum Espresso Software Package

    NASA Astrophysics Data System (ADS)

    Barnes, Taylor; Kurth, Thorsten; Carrier, Pierre; Wichmann, Nathan; Prendergast, David; Kent, Paul; Deslippe, Jack

    Accurate simulation of condensed matter at the nanoscale requires careful treatment of the exchange interaction between electrons. In the context of plane-wave DFT, these interactions are typically represented through the use of approximate functionals. Greater accuracy can often be obtained through the use of functionals that incorporate some fraction of exact exchange; however, evaluation of the exact exchange potential is often prohibitively expensive. We present an improved algorithm for the parallel computation of exact exchange in Quantum Espresso, an open-source software package for plane-wave DFT simulation. Through the use of aggressive load balancing and on-the-fly transformation of internal data structures, our code exhibits speedups of approximately an order of magnitude for practical calculations. Additional optimizations are presented targeting the many-core Intel Xeon-Phi ``Knights Landing'' architecture, which largely powers NERSC's new Cori system. We demonstrate the successful application of the code to difficult problems, including simulation of water at a platinum interface and computation of the X-ray absorption spectra of transition metal oxides.

  15. On the relationship between the specific heat enhancement of salt-based nanofluids and the ionic exchange capacity of nanoparticles.

    PubMed

    Mondragón, Rosa; Juliá, J Enrique; Cabedo, Luis; Navarrete, Nuria

    2018-05-14

    Nanoparticles have been used in thermal applications to increase the specific heat of the molten salts used in Concentrated Solar Power plants for thermal energy storage. Although several mechanisms for abnormal enhancement have been proposed, they are still being investigated and more research is necessary. However, this nanoparticle-salt interaction can also be found in chemical applications in which nanoparticles have proved suitable to be used as an adsorbent for nitrate removal given their high specific surface, reactivity and ionic exchange capacity. In this work, the ionic exchange capacity mechanism for the nanoparticles functionalization phenomenon was evaluated. The ionic exchange capacity of silica and alumina nanoparticles dispersed in lithium, sodium and potassium nitrates was measured. Fourier-transform infrared spectroscopy tests confirmed the adsorption of nitrate ions on the nanoparticle surface. A relationship between the ionic exchange capacity of nanoparticles and the specific heat enhancement of doped molten salts was proposed for the first time.

  16. Real-time observation of cation exchange kinetics and dynamics at the muscovite-water interface

    PubMed Central

    Lee, Sang Soo; Fenter, Paul; Nagy, Kathryn L.; Sturchio, Neil C.

    2017-01-01

    Ion exchange at charged solid–liquid interfaces is central to a broad range of chemical and transport phenomena. Real-time observations of adsorption/desorption at the molecular-scale elucidate exchange reaction pathways. Here we report temporal variation in the distribution of Rb+ species at the muscovite (001)–water interface during exchange with Na+. Time-resolved resonant anomalous X-ray reflectivity measurements at 25 °C reveal that Rb+ desorption occurs over several tens of seconds during which thermodynamically stable inner-sphere Rb+ slowly transforms to a less stable outer-sphere Rb+. In contrast, Rb+ adsorption is about twice as fast, proceeding from Rb+ in the bulk solution to the stable inner-sphere species. The Arrhenius plot of the adsorption/desorption rate constants measured from 9 to 55 °C shows that the pre-exponential factor for desorption is significantly smaller than that for adsorption, indicating that this reduced attempt frequency of cation detachment largely explains the slow cation exchange processes at the interface. PMID:28598428

  17. Phase correlation of foreign exchange time series

    NASA Astrophysics Data System (ADS)

    Wu, Ming-Chya

    2007-03-01

    Correlation of foreign exchange rates in currency markets is investigated based on the empirical data of USD/DEM and USD/JPY exchange rates for a period from February 1 1986 to December 31 1996. The return of exchange time series is first decomposed into a number of intrinsic mode functions (IMFs) by the empirical mode decomposition method. The instantaneous phases of the resultant IMFs calculated by the Hilbert transform are then used to characterize the behaviors of pricing transmissions, and the correlation is probed by measuring the phase differences between two IMFs in the same order. From the distribution of phase differences, our results show explicitly that the correlations are stronger in daily time scale than in longer time scales. The demonstration for the correlations in periods of 1986-1989 and 1990-1993 indicates two exchange rates in the former period were more correlated than in the latter period. The result is consistent with the observations from the cross-correlation calculation.

  18. Post-synthetic transformation of a Zn(ii) polyhedral coordination network into a new supramolecular isomer of HKUST-1.

    PubMed

    Chen, Yao; Wojtas, Lukasz; Ma, Shengqian; Zaworotko, Michael J; Zhang, Zhenjie

    2017-08-03

    A Zn-based porphyrin containing metal-organic material (porphMOM-1) was transformed into a novel Cu-based porphyrin-encapsulating metal-organic material (porph@HKUST-1-β) via a one-pot post-synthetic modification (PSM) process involving both metal ion exchange and linker installation of trimesic acid. HKUST-1-β is the first example of yao topology and is to our knowledge the first supramolecular isomer of the archetypal coordination network HKUST-1.

  19. Probing biological redox chemistry with large amplitude Fourier transformed ac voltammetry

    PubMed Central

    Adamson, Hope

    2017-01-01

    Biological electron-exchange reactions are fundamental to life on earth. Redox reactions underpin respiration, photosynthesis, molecular biosynthesis, cell signalling and protein folding. Chemical, biomedical and future energy technology developments are also inspired by these natural electron transfer processes. Further developments in techniques and data analysis are required to gain a deeper understanding of the redox biochemistry processes that power Nature. This review outlines the new insights gained from developing Fourier transformed ac voltammetry as a tool for protein film electrochemistry. PMID:28804798

  20. Synthesis, characterization and applications of a new cation exchanger tamarind sulphonic acid (TSA) resin.

    PubMed

    Singh, A V; Sharma, Naresh Kumar; Rathore, Abhay S

    2012-01-01

    A new composite cation exchanger, tamarind sulphonic acid (TSA) resin has been synthesized. The chemically modified TSA ion exchange resin has been used for the removal and preconcentration of Zn2+, Cd2+, Fe2+, Co2+ and Cu2+ ions in aqueous solution and effluent from the Laxmi steel plant in Jodhpur, India. This type of composite represents a new class of hybrid ion exchangers with good ion exchange capacity, stability, reproducibility and selectivity for toxic metal ions found in effluent from the steel industry. The characterization of the resin was carried out by determining the ion-exchange capacity, elemental analysis, pH titration, Fourier transform infrared spectra and thermal analysis. The distribution coefficients (K(d)) of toxic metal ions were determined in a reference aqueous solution and the steel plant effluent at different pH values; the absorbency of different metal ions on the TSA resin was studied for up to 10 cycles. The adsorption of different metal ions on TSA resin follows the order: Co2+ > Cu2+ > Zn2+ > Fe2+ > Cd2+. The ion exchange capacity of TSA resin is 2.87%.

  1. Solvent-induced controllable synthesis, single-crystal to single-crystal transformation and encapsulation of Alq3 for modulated luminescence in (4,8)-connected metal-organic frameworks.

    PubMed

    Lan, Ya-Qian; Jiang, Hai-Long; Li, Shun-Li; Xu, Qiang

    2012-07-16

    In this work, for the first time, we have systematically demonstrated that solvent plays crucial roles in both controllable synthesis of metal-organic frameworks (MOFs) and their structural transformation process. With solvent as the only variable, five new MOFs with different structures have been constructed, in which one MOF undergoes solvent-induced single-crystal to single-crystal (SCSC) transformation that involves not only solvent exchange but also the cleavage and formation of coordination bonds. Particularly, a significant crystallographic change has been realized through an unprecedented three-step SCSC transformation process. Furthermore, we have demonstrated that the obtained MOF could be an excellent host for chromophores such as Alq3 for modulated luminescent properties.

  2. Battle Management Language Transformations

    DTIC Science & Technology

    2006-10-01

    Simulation (M&S) systems. Battlefield Management Language (BML) is being developed as a common representation of military mission suitable for automated ... processing . Within NATO the task group MSG-048 Coalition BML is defining a BML using the Joint Command, Control and Consultation Information Exchange

  3. Policy analysis and recommendations for the DCM research data exchange.

    DOT National Transportation Integrated Search

    2012-07-01

    This report is a policy analysis and set of recommendations regarding open data policies and policies for new, transformative data environments that are being developed as part of the Connected Vehicle research program. It is presented in three secti...

  4. Glass-bonded iodosodalite waste form for immobilization of 129 I

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chong, Saehwa; Peterson, Jacob A.; Riley, Brian J.

    Immobilization of radioiodine (e.g., 129I, 131I) is an important need for current and future nuclear fuel cycles. For the current work, iodosodalite [Na8(AlSiO4)6I2] was synthesized hydrothermally from metakaolin, NaI, and NaOH. Following hydrothermal treatment, dried unwashed powders were used to make glass-bonded iodosodalite waste forms by heating pressed pellets at 650, 750, or 850 °C with two different types of sodium borosilicate glass binders, i.e., NBS-4 and SA-800. These heat-treated specimens were characterized with X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, thermal analysis, porosity and density measurements, neutron activation analysis, and inductively-coupled plasma mass spectrometry. Themore » pellets mixed with 10 mass% of NBS-4 or SA-800 and heat-treated at 750 °C contained relatively high percentage iodine retention (~44-47 % of the maximum iodine loading) with relatively low porosities, while other pellets with higher percentages iodine retention either contained higher porosity or were not completely sintered. ASTM C1308 chemical durability tests of monolithic specimens showed a large initial release of Na, Al, Si, and I on the first day, possibly from water-soluble salt crystals or non-durable amorphous phases. Release rates of Na and Si were higher than for Al and I, probably due to a poorly durable Na-Si-O phase from the glass bonding matrix. The cumulative normalized release of iodine was 12.5 g m-2 for the first 10 1-d exchanges, suggestive of coherent dissolution. The average release rate from 10-24 days during the 7-d exchange intervals was 0.2336 g m-2 d-1.« less

  5. Nonuniform sampling and non-Fourier signal processing methods in multidimensional NMR

    PubMed Central

    Mobli, Mehdi; Hoch, Jeffrey C.

    2017-01-01

    Beginning with the introduction of Fourier Transform NMR by Ernst and Anderson in 1966, time domain measurement of the impulse response (the free induction decay, FID) consisted of sampling the signal at a series of discrete intervals. For compatibility with the discrete Fourier transform (DFT), the intervals are kept uniform, and the Nyquist theorem dictates the largest value of the interval sufficient to avoid aliasing. With the proposal by Jeener of parametric sampling along an indirect time dimension, extension to multidimensional experiments employed the same sampling techniques used in one dimension, similarly subject to the Nyquist condition and suitable for processing via the discrete Fourier transform. The challenges of obtaining high-resolution spectral estimates from short data records using the DFT were already well understood, however. Despite techniques such as linear prediction extrapolation, the achievable resolution in the indirect dimensions is limited by practical constraints on measuring time. The advent of non-Fourier methods of spectrum analysis capable of processing nonuniformly sampled data has led to an explosion in the development of novel sampling strategies that avoid the limits on resolution and measurement time imposed by uniform sampling. The first part of this review discusses the many approaches to data sampling in multidimensional NMR, the second part highlights commonly used methods for signal processing of such data, and the review concludes with a discussion of other approaches to speeding up data acquisition in NMR. PMID:25456315

  6. In Situ Tracking Kinetic Pathways of Li+/Na+ Substitution during Ion-Exchange Synthesis of LixNa1.5-xVOPO4F0.5.

    PubMed

    Park, Young-Uk; Bai, Jianming; Wang, Liping; Yoon, Gabin; Zhang, Wei; Kim, Hyungsub; Lee, Seongsu; Kim, Sung-Wook; Looney, J Patrick; Kang, Kisuk; Wang, Feng

    2017-09-13

    Ion exchange is a ubiquitous phenomenon central to wide industrial applications, ranging from traditional (bio)chemical separation to the emerging chimie douce synthesis of materials with metastable structure for batteries and other energy applications. The exchange process is complex, involving substitution and transport of different ions under non-equilibrium conditions, and thus difficult to probe, leaving a gap in mechanistic understanding of kinetic exchange pathways toward final products. Herein, we report in situ tracking kinetic pathways of Li + /Na + substitution during solvothermal ion-exchange synthesis of Li x Na 1.5-x VOPO 4 F 0.5 (0 ≤ x ≤ 1.5), a promising multi-Li polyanionic cathode for batteries. The real-time observation, corroborated by first-principles calculations, reveals a selective replacement of Na + by Li + , leading to peculiar Na + /Li + /vacancy orderings in the intermediates. Contradicting the traditional belief of facile topotactic substitution via solid solution reaction, an abrupt two-phase transformation occurs and predominantly governs the kinetics of ion exchange and transport in the 1D polyanionic framework, consequently leading to significant difference of Li stoichiometry and electrochemical properties in the exchanged products. The findings may help to pave the way for rational design of ion exchange synthesis for making new materials.

  7. Advice networks in teams: the role of transformational leadership and members' core self-evaluations.

    PubMed

    Zhang, Zhen; Peterson, Suzanne J

    2011-09-01

    This article examines the team-level factors promoting advice exchange networks in teams. Drawing upon theory and research on transformational leadership, team diversity, and social networks, we hypothesized that transformational leadership positively influences advice network density in teams and that advice network density serves as a mediating mechanism linking transformational leadership to team performance. We further hypothesized a 3-way interaction in which members' mean core self-evaluation (CSE) and diversity in CSE jointly moderate the transformational leadership-advice network density relationship, such that the relationship is positive and stronger for teams with low diversity in CSE and high mean CSE. In addition, we expected that advice network centralization attenuates the positive influence of network density on team performance. Results based on multisource data from 79 business unit management teams showed support for these hypotheses. The results highlight the pivotal role played by transformational leadership and team members' CSEs in enhancing team social networks and, ultimately, team effectiveness. PsycINFO Database Record (c) 2011 APA, all rights reserved

  8. On the Limiting Markov Process of Energy Exchanges in a Rarely Interacting Ball-Piston Gas

    NASA Astrophysics Data System (ADS)

    Bálint, Péter; Gilbert, Thomas; Nándori, Péter; Szász, Domokos; Tóth, Imre Péter

    2017-02-01

    We analyse the process of energy exchanges generated by the elastic collisions between a point-particle, confined to a two-dimensional cell with convex boundaries, and a `piston', i.e. a line-segment, which moves back and forth along a one-dimensional interval partially intersecting the cell. This model can be considered as the elementary building block of a spatially extended high-dimensional billiard modeling heat transport in a class of hybrid materials exhibiting the kinetics of gases and spatial structure of solids. Using heuristic arguments and numerical analysis, we argue that, in a regime of rare interactions, the billiard process converges to a Markov jump process for the energy exchanges and obtain the expression of its generator.

  9. A model for foreign exchange markets based on glassy Brownian systems

    PubMed Central

    Trinidad-Segovia, J. E.; Clara-Rahola, J.; Puertas, A. M.; De las Nieves, F. J.

    2017-01-01

    In this work we extend a well-known model from arrested physical systems, and employ it in order to efficiently depict different currency pairs of foreign exchange market price fluctuation distributions. We consider the exchange rate price in the time range between 2010 and 2016 at yearly time intervals and resolved at one minute frequency. We then fit the experimental datasets with this model, and find significant qualitative symmetry between price fluctuation distributions from the currency market, and the ones belonging to colloidal particles position in arrested states. The main contribution of this paper is a well-known physical model that does not necessarily assume the independent and identically distributed (i.i.d.) restrictive condition. PMID:29206868

  10. Esterification of phenyl acetic acid with p-cresol using metal cation exchanged montmorillonite nanoclay catalysts.

    PubMed

    Bhaskar, M; Surekha, M; Suma, N

    2018-02-01

    The liquid phase esterification of phenyl acetic acid with p -cresol over different metal cation exchanged montmorillonite nanoclays yields p -cresyl phenyl acetate. Different metal cation exchanged montmorillonite nanoclays (M n +  = Al 3+ , Zn 2+ , Mn 2+ , Fe 3+ , Cu 2+ ) were prepared and the catalytic activity was studied. The esterification reaction was conducted by varying molar ratio of the reactants, reaction time and catalyst amount on the yield of the ester. Among the different metal cation exchanged catalysts used, Al 3+ -montmorillonite nanoclay was found to be more active. The characterization of the material used was studied under different techniques, namely X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. The product obtained, p -cresyl phenyl acetate, was identified by thin-layer chromotography and confirmed by Fourier transform infrared, 1 H NMR and 13 C NMR. The regeneration activity of used catalyst was also investigated up to fourth generation.

  11. Accurate Semilocal Density Functional for Condensed-Matter Physics and Quantum Chemistry.

    PubMed

    Tao, Jianmin; Mo, Yuxiang

    2016-08-12

    Most density functionals have been developed by imposing the known exact constraints on the exchange-correlation energy, or by a fit to a set of properties of selected systems, or by both. However, accurate modeling of the conventional exchange hole presents a great challenge, due to the delocalization of the hole. Making use of the property that the hole can be made localized under a general coordinate transformation, here we derive an exchange hole from the density matrix expansion, while the correlation part is obtained by imposing the low-density limit constraint. From the hole, a semilocal exchange-correlation functional is calculated. Our comprehensive test shows that this functional can achieve remarkable accuracy for diverse properties of molecules, solids, and solid surfaces, substantially improving upon the nonempirical functionals proposed in recent years. Accurate semilocal functionals based on their associated holes are physically appealing and practically useful for developing nonlocal functionals.

  12. Exchange-driven growth.

    PubMed

    Ben-Naim, E; Krapivsky, P L

    2003-09-01

    We study a class of growth processes in which clusters evolve via exchange of particles. We show that depending on the rate of exchange there are three possibilities: (I) Growth-clusters grow indefinitely, (II) gelation-all mass is transformed into an infinite gel in a finite time, and (III) instant gelation. In regimes I and II, the cluster size distribution attains a self-similar form. The large size tail of the scaling distribution is Phi(x) approximately exp(-x(2-nu)), where nu is a homogeneity degree of the rate of exchange. At the borderline case nu=2, the distribution exhibits a generic algebraic tail, Phi(x) approximately x(-5). In regime III, the gel nucleates immediately and consumes the entire system. For finite systems, the gelation time vanishes logarithmically, T approximately [lnN](-(nu-2)), in the large system size limit N--> infinity. The theory is applied to coarsening in the infinite range Ising-Kawasaki model and in electrostatically driven granular layers.

  13. Anion exchange of the cationic layered material [Pb2F2]2+.

    PubMed

    Fei, Honghan; Pham, Catherine H; Oliver, Scott R J

    2012-07-04

    We demonstrate the complete exchange of the interlamellar anions of a 2-D cationic inorganic material. The α,ω-alkanedisulfonates were exchanged for α,ω-alkanedicarboxylates, leading to two new cationic materials with the same [Pb(2)F(2)](2+) layered architecture. Both were solved by single crystal X-ray diffraction and the transformation also followed by in situ optical microscopy and ex situ powder X-ray diffraction. This report represents a rare example of metal-organic framework displaying highly efficient and complete replacement of its anionic organic linker while retaining the original extended inorganic layer. It also opens up further possibilities for introducing other anions or abatement of problematic anions such as pharmaceuticals and their metabolites.

  14. Noniterative accurate algorithm for the exact exchange potential of density-functional theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cinal, M.; Holas, A.

    2007-10-15

    An algorithm for determination of the exchange potential is constructed and tested. It represents a one-step procedure based on the equations derived by Krieger, Li, and Iafrate (KLI) [Phys. Rev. A 46, 5453 (1992)], implemented already as an iterative procedure by Kuemmel and Perdew [Phys. Rev. Lett. 90, 043004 (2003)]. Due to suitable transformation of the KLI equations, we can solve them avoiding iterations. Our algorithm is applied to the closed-shell atoms, from Be up to Kr, within the DFT exchange-only approximation. Using pseudospectral techniques for representing orbitals, we obtain extremely accurate values of total and orbital energies with errorsmore » at least four orders of magnitude smaller than known in the literature.« less

  15. Leveraging private and public exchanges in an employee benefits strategy.

    PubMed

    Margolis, Susan; Thompson, Michael

    2013-01-01

    Health reform is helping to transform the health insurance marketplace and facilitate new opportunities to reevaluate and restructure the underlying framework of employer-sponsored benefits. Central to these opportunities is the emergence of public health exchanges at the state and federal levels offering a coordinated platform of diverse designs and health plans available on a guaranteed issue basis and often with government-provided subsidies. Parallel and complementary to this trend is the emergence of private health exchanges that similarly offer a diversity of plans on a variety of bases. This article shows why, together, these offerings provide potential streamlined solutions for employers as they reevaluate how they facilitate and support access to affordable coverage for their employees (and retirees).

  16. Postassembly Transformation of a Catalytically Active Composite Material, Pt@ZIF-8, via Solvent-Assisted Linker Exchange.

    PubMed

    Stephenson, Casey J; Hupp, Joseph T; Farha, Omar K

    2016-02-15

    2-Methylimidazolate linkers of Pt@ZIF-8 are exchanged with imidazolate using solvent-assisted linker exchange (SALE) to expand the apertures of the parent material and create Pt@SALEM-2. Characterization of the material before and after SALE was performed. Both materials are active as catalysts for the hydrogenation of 1-octene, whereas the hydrogenation of cis-cyclohexene occurred only with Pt@SALEM-2, consistent with larger apertures for the daughter material. The largest substrate, β-pinene, proved to be unreactive with H2 when either material was employed as a candidate catalyst, supporting the contention that substrate molecules, for both composites, must traverse the metal-organic framework component in order to reach the catalytic nanoparticles.

  17. Molecular dissection of nutrient exchange at the insect-microbial interface.

    PubMed

    Douglas, Angela E

    2014-10-01

    Genome research is transforming our understanding of nutrient exchange between insects and intracellular bacteria. A key characteristic of these bacteria is their small genome size and gene content. Their fastidious and inflexible nutritional requirements are met by multiple metabolites from the insect host cell. Although the bacteria have generally retained genes coding the synthesis of nutrients required by the insect, some apparently critical genes have been lost, and compensated for by shared metabolic pathways with the insect host or supplementary bacteria with complementary metabolic capabilities. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Functionalized alkoxy arene diazonium salts from paracetamol.

    PubMed

    Schmidt, Bernd; Berger, René; Hölter, Frank

    2010-03-21

    Arene diazonium tetrafluoroborates can be synthesized from aromatic acetamides via a sequence of deacetylation, diazotation and precipitation, induced by anion exchange. The reaction is conducted as a convenient one-flask transformation with consecutive addition of the appropriate reagents. Exchange of solvents or removal of byproducts prior to isolation of the product is not required. The arene diazonium salts are isolated from the reaction mixture by simple filtration. Two complementary protocols are presented, and the utility of the reaction is exemplified for a synthesis of the diarylheptanoid natural product de-O-methyl centrolobine.

  19. BARRIERS TO GENETIC EXCHANGE BETWEEN BACTERIAL SPECIES: STREPTOCOCCUS PNEUMONIAE TRANSFORMATION. (R825348)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. The influence of organizational characteristics on employee solidarity in the long-term care sector

    PubMed Central

    Cramm, Jane M; Strating, Mathilde MH; Nieboer, Anna P

    2013-01-01

    Aim This article is a report of a study that identifies organizational characteristics explaining employee solidarity in the long-term care sector. Background Employee solidarity reportedly improves organizations’ effectiveness and efficiency. Although general research on solidarity in organizations is available, the impact of the organizational context on solidarity in long-term care settings is lacking. Design Cross-sectional survey. Method The study was carried out in Dutch long-term care. A total of 313 nurses, managers and other care professionals in 23 organizations were involved. Organizational characteristics studied were centralization, hierarchical culture, formal and informal exchange of information and leadership style. The study was carried out in 2009. Findings All organizational characteristics significantly correlated with employee solidarity in the univariate analyses. In the multivariate analyses hierarchical culture, centralization, exchange of formal and informal information and transformational leadership appears to be important for solidarity among nurses, managers and other professionals in long-term care organizations, but not transactional and passive leadership styles. Conclusion The study increased our knowledge of solidarity among nurses, managers and other professionals in the long-term care settings. Organizational characteristics that enhance solidarity are high levels of formal and informal information exchange, less hierarchical authority, decentralization and transformational leadership styles. PMID:22551056

  1. The influence of organizational characteristics on employee solidarity in the long-term care sector.

    PubMed

    Cramm, Jane M; Strating, Mathilde M H; Nieboer, Anna P

    2013-03-01

    This article is a report of a study that identifies organizational characteristics explaining employee solidarity in the long-term care sector. Employee solidarity reportedly improves organizations' effectiveness and efficiency. Although general research on solidarity in organizations is available, the impact of the organizational context on solidarity in long-term care settings is lacking. Cross-sectional survey. The study was carried out in Dutch long-term care. A total of 313 nurses, managers and other care professionals in 23 organizations were involved. Organizational characteristics studied were centralization, hierarchical culture, formal and informal exchange of information and leadership style. The study was carried out in 2009. Findings.  All organizational characteristics significantly correlated with employee solidarity in the univariate analyses. In the multivariate analyses hierarchical culture, centralization, exchange of formal and informal information and transformational leadership appears to be important for solidarity among nurses, managers and other professionals in long-term care organizations, but not transactional and passive leadership styles. The study increased our knowledge of solidarity among nurses, managers and other professionals in the long-term care settings. Organizational characteristics that enhance solidarity are high levels of formal and informal information exchange, less hierarchical authority, decentralization and transformational leadership styles. © 2012 Blackwell Publishing Ltd.

  2. Transformation based endorsement systems

    NASA Technical Reports Server (NTRS)

    Sudkamp, Thomas

    1988-01-01

    Evidential reasoning techniques classically represent support for a hypothesis by a numeric value or an evidential interval. The combination of support is performed by an arithmetic rule which often requires restrictions to be placed on the set of possibilities. These assumptions usually require the hypotheses to be exhausitive and mutually exclusive. Endorsement based classification systems represent support for the alternatives symbolically rather than numerically. A framework for constructing endorsement systems is presented in which transformations are defined to generate and update the knowledge base. The interaction of the knowledge base and transformations produces a non-monotonic reasoning system. Two endorsement based reasoning systems are presented to demonstrate the flexibility of the transformational approach for reasoning with ambiguous and inconsistent information.

  3. The investigation of the bio-oil produced by hydrothermal liquefaction of Spirulina platensis using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Kostyukevich, Yury; Vlaskin, Mikhail; Vladimirov, Gleb; Zherebker, Alexander; Kononikhin, Alexey; Popov, Igor; Nikolaev, Eugene

    2017-04-01

    We report the investigation of the hydrothermal liquefaction products of the Spirulina platensis microalgae by using the Fourier transform ion cyclotron resonance mass spectrometry. The hydrothermal liquefaction produced two fractions: one with boiling temperature below 300℃ and the dense residue that remained in the reactor. It was observed that N 2 and N classes of compounds that dominate in the positive ESI Fourier transform ion cyclotron resonance spectra for both fractions, and that the light fraction is considerably more saturated then the heavy one. The performed hydrogen/deuterium exchange reaction indicated the presence of the onium compounds in the bio-oil.

  4. The whole number axis integer linear transformation reversible information hiding algorithm on wavelet domain

    NASA Astrophysics Data System (ADS)

    Jiang, Zhuo; Xie, Chengjun

    2013-12-01

    This paper improved the algorithm of reversible integer linear transform on finite interval [0,255], which can realize reversible integer linear transform in whole number axis shielding data LSB (least significant bit). Firstly, this method use integer wavelet transformation based on lifting scheme to transform the original image, and select the transformed high frequency areas as information hiding area, meanwhile transform the high frequency coefficients blocks in integer linear way and embed the secret information in LSB of each coefficient, then information hiding by embedding the opposite steps. To extract data bits and recover the host image, a similar reverse procedure can be conducted, and the original host image can be lossless recovered. The simulation experimental results show that this method has good secrecy and concealment, after conducted the CDF (m, n) and DD (m, n) series of wavelet transformed. This method can be applied to information security domain, such as medicine, law and military.

  5. Limited Rationality and Its Quantification Through the Interval Number Judgments With Permutations.

    PubMed

    Liu, Fang; Pedrycz, Witold; Zhang, Wei-Guo

    2017-12-01

    The relative importance of alternatives expressed in terms of interval numbers in the fuzzy analytic hierarchy process aims to capture the uncertainty experienced by decision makers (DMs) when making a series of comparisons. Under the assumption of full rationality, the judgements of DMs in the typical analytic hierarchy process could be consistent. However, since the uncertainty in articulating the opinions of DMs is unavoidable, the interval number judgements are associated with the limited rationality. In this paper, we investigate the concept of limited rationality by introducing interval multiplicative reciprocal comparison matrices. By analyzing the consistency of interval multiplicative reciprocal comparison matrices, it is observed that the interval number judgements are inconsistent. By considering the permutations of alternatives, the concepts of approximation-consistency and acceptable approximation-consistency of interval multiplicative reciprocal comparison matrices are proposed. The exchange method is designed to generate all the permutations. A novel method of determining the interval weight vector is proposed under the consideration of randomness in comparing alternatives, and a vector of interval weights is determined. A new algorithm of solving decision making problems with interval multiplicative reciprocal preference relations is provided. Two numerical examples are carried out to illustrate the proposed approach and offer a comparison with the methods available in the literature.

  6. A flexible model for multivariate interval-censored survival times with complex correlation structure.

    PubMed

    Falcaro, Milena; Pickles, Andrew

    2007-02-10

    We focus on the analysis of multivariate survival times with highly structured interdependency and subject to interval censoring. Such data are common in developmental genetics and genetic epidemiology. We propose a flexible mixed probit model that deals naturally with complex but uninformative censoring. The recorded ages of onset are treated as possibly censored ordinal outcomes with the interval censoring mechanism seen as arising from a coarsened measurement of a continuous variable observed as falling between subject-specific thresholds. This bypasses the requirement for the failure times to be observed as falling into non-overlapping intervals. The assumption of a normal age-of-onset distribution of the standard probit model is relaxed by embedding within it a multivariate Box-Cox transformation whose parameters are jointly estimated with the other parameters of the model. Complex decompositions of the underlying multivariate normal covariance matrix of the transformed ages of onset become possible. The new methodology is here applied to a multivariate study of the ages of first use of tobacco and first consumption of alcohol without parental permission in twins. The proposed model allows estimation of the genetic and environmental effects that are shared by both of these risk behaviours as well as those that are specific. 2006 John Wiley & Sons, Ltd.

  7. Mixing rates and limit theorems for random intermittent maps

    NASA Astrophysics Data System (ADS)

    Bahsoun, Wael; Bose, Christopher

    2016-04-01

    We study random transformations built from intermittent maps on the unit interval that share a common neutral fixed point. We focus mainly on random selections of Pomeu-Manneville-type maps {{T}α} using the full parameter range 0<α <∞ , in general. We derive a number of results around a common theme that illustrates in detail how the constituent map that is fastest mixing (i.e. smallest α) combined with details of the randomizing process, determines the asymptotic properties of the random transformation. Our key result (theorem 1.1) establishes sharp estimates on the position of return time intervals for the quenched dynamics. The main applications of this estimate are to limit laws (in particular, CLT and stable laws, depending on the parameters chosen in the range 0<α <1 ) for the associated skew product; these are detailed in theorem 3.2. Since our estimates in theorem 1.1 also hold for 1≤slant α <∞ we study a second class of random transformations derived from piecewise affine Gaspard-Wang maps, prove existence of an infinite (σ-finite) invariant measure and study the corresponding correlation asymptotics. To the best of our knowledge, this latter kind of result is completely new in the setting of random transformations.

  8. Determinants of choice for pigeons and humans on concurrent-chains schedules of reinforcement.

    PubMed

    Belke, T W; Pierce, W D; Powell, R A

    1989-09-01

    Concurrent-chains schedules of reinforcement were arranged for humans and pigeons. Responses of humans were reinforced with tokens exchangeable for money, and key pecks of 4 birds were reinforced with food. Variable-interval 30-s and 40-s schedules operated in the terminal links of the chains. Condition 1 exposed subjects to variable-interval 90-s and variable-interval 30-s initial links, respectively. Conditions 2 and 3 arranged equal initial-link schedules of 40 s or 120 s. Experimental conditions tested the descriptive adequacy of five equations: reinforcement density, delay reduction, modified delay reduction, matching and maximization. Results based on choice proportions and switch rates during the initial links showed that pigeons behaved in accord with delay-reduction models, whereas humans maximized overall rate of reinforcement. As discussed by Logue and associates in self-control research, different types of reinforcement may affect sensitivity to delay differentially. Pigeons' responses were reinforced with food, a reinforcer that is consumable upon presentation. Humans' responses were reinforced with money, a reinforcer exchanged for consumable reinforcers after it was earned. Reinforcers that are immediately consumed may generate high sensitivity to delay and behavior described as delay reduction. Reinforces with longer times to consumption may generate low sensitivity to delay and behavior that maximizes overall payoff.

  9. Experimental study on the optimal purge duration of a proton exchange membrane fuel cell with a dead-ended anode

    NASA Astrophysics Data System (ADS)

    Lin, Yu-Fen; Chen, Yong-Song

    2017-02-01

    When a proton exchange membrane fuel cell (PEMFC) is operated with a dead-ended anode, impurities gradually accumulate within the anode, resulting in a performance drop. An anode purge is thereby ultimately required to remove impurities within the anode. A purge strategy comprises purge interval (valve closed) and purge duration (valve is open). A short purge interval causes frequent and unnecessary activation of the valve, whereas a long purge interval leads to excessive impurity accumulation. A short purge duration causes an incomplete performance recovery, whereas a long purge duration results in low hydrogen utilization. In this study, a series of experimental trials was conducted to simultaneously measure the hydrogen supply rate and power generation of a PEMFC at a frequency of 50 Hz for various operating current density levels and purge durations. The effect of purge duration on the cell's energy efficiency was subsequently analyzed and discussed. The results showed that the optimal purge duration for the PEMFC was approximately 0.2 s. Based on the results of this study, a methodical process for determining optimal purge durations was ultimately proposed for widespread application. Purging approximately one-fourth of anode gas can obtain optimal energy efficiency for a PEMFC with a dead-ended anode.

  10. Modeling Geomagnetically Induced Currents From Magnetometer Measurements: Spatial Scale Assessed With Reference Measurements

    NASA Astrophysics Data System (ADS)

    Butala, Mark D.; Kazerooni, Maryam; Makela, Jonathan J.; Kamalabadi, Farzad; Gannon, Jennifer L.; Zhu, Hao; Overbye, Thomas J.

    2017-10-01

    Solar-driven disturbances generate geomagnetically induced currents (GICs) that can result in power grid instability and, in the most extreme cases, even failure. Magnetometers provide direct measurements of the geomagnetic disturbance (GMD) effect on the surface magnetic field and GIC response can be determined from the power grid topology and engineering parameters. This paper considers this chain of models: transforming surface magnetic field disturbance to induced surface electric field through an electromagnetic transfer function and, then, induced surface electric field to GIC using the PowerWorld simulator to model a realistic power grid topology. Comparisons are made to transformer neutral current reference measurements provided by the American Transmission Company. Three GMD intervals are studied, with the Kp index reaching 8- on 2 October 2013, 7 on 1 June 2013, and 6- on 9 October 2013. Ultimately, modeled to measured GIC correlations are analyzed as a function of magnetometer to GIC sensor distance. Results indicate that modeling fidelity during the three studied GMD intervals is strongly dependent on both magnetometer to substation transformer baseline distance and GMD intensity.

  11. Oil spill source identification by principal component analysis of electrospray ionization Fourier transform ion cyclotron resonance mass spectra.

    PubMed

    Corilo, Yuri E; Podgorski, David C; McKenna, Amy M; Lemkau, Karin L; Reddy, Christopher M; Marshall, Alan G; Rodgers, Ryan P

    2013-10-01

    One fundamental challenge with either acute or chronic oil spills is to identify the source, especially in highly polluted areas, near natural oil seeps, when the source contains more than one petroleum product or when extensive weathering has occurred. Here we focus on heavy fuel oil that spilled (~200,000 L) from two suspected fuel tanks that were ruptured on the motor vessel (M/V) Cosco Busan when it struck the San Francisco-Oakland Bay Bridge in November 2007. We highlight the utility of principal component analysis (PCA) of elemental composition data obtained by high resolution FT-ICR mass spectrometry to correctly identify the source of environmental contamination caused by the unintended release of heavy fuel oil (HFO). Using ultrahigh resolution electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry, we uniquely assigned thousands of elemental compositions of heteroatom-containing species in neat samples from both tanks and then applied principal component analysis. The components were based on double bond equivalents for constituents of elemental composition, CcHhN1S1. To determine if the fidelity of our source identification was affected by weathering, field samples were collected at various intervals up to two years after the spill. We are able to identify a suite of polar petroleum markers that are environmentally persistent, enabling us to confidently identify that only one tank was the source of the spilled oil: in fact, a single principal component could account for 98% of the variance. Although identification is unaffected by the presence of higher polarity, petrogenic oxidation (weathering) products, future studies may require removal of such species by anion exchange chromatography prior to mass spectral analysis due to their preferential ionization by ESI.

  12. Co-metal-organic-frameworks with pure uniform crystal morphology prepared via Co2+ exchange-mediated transformation from Zn-metallogels for luminol catalysed chemiluminescence.

    PubMed

    Tang, Xue Qian; Xiao, Bo Wen; Li, Chun Mei; Wang, Dong Mei; Huang, Cheng Zhi; Li, Yuan Fang

    2017-03-15

    Cation exchange-mediated transformation from Zn-metallogels (MOGs), which was a mild facile strategy relative to the demanding hydrothermal method, was employed to develop Co 2+ metal-organic frameworks (Co-MOFs) at room temperature. The obtained Co-MOFs was of uniform octahedral morphology and possessed high activity to catalyze luminol chemiluminescence without extra oxidants. By adding cysteine, the CL emission of luminol-Co-MOFs system was further enhanced. Based on this phenomenon, Co-MOFs was utilized to build a practical sensing platform for cysteine determination. Under the optimized conditions, the relative CL intensity (ΔI) was proportional to the concentration of cysteine in the range of 2-10μM, and the detection limit was 0.49μM (3S/N). Moreover, the established method was applied to the determination of cysteine in commercially available pharmaceutical injections. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Modeling of a data exchange process in the Automatic Process Control System on the base of the universal SCADA-system

    NASA Astrophysics Data System (ADS)

    Topolskiy, D.; Topolskiy, N.; Solomin, E.; Topolskaya, I.

    2016-04-01

    In the present paper the authors discuss some ways of solving energy saving problems in mechanical engineering. In authors' opinion one of the ways of solving this problem is integrated modernization of power engineering objects of mechanical engineering companies, which should be intended for the energy supply control efficiency increase and electric energy commercial accounting improvement. The author have proposed the usage of digital current and voltage transformers for these purposes. To check the compliance of this equipment with the IEC 61850 International Standard, we have built a mathematic model of the data exchange process between measuring transformers and a universal SCADA-system. The results of modeling show that the discussed equipment corresponds to the mentioned Standard requirements and the usage of the universal SCADA-system for these purposes is preferable and economically reasonable. In modeling the authors have used the following software: MasterScada, Master OPC_DI_61850, OPNET.

  14. Dynamics of liquids, molecules, and proteins measured with ultrafast 2D IR vibrational echo chemical exchange spectroscopy.

    PubMed

    Fayer, M D

    2009-01-01

    A wide variety of molecular systems undergo fast structural changes under thermal equilibrium conditions. Such transformations are involved in a vast array of chemical problems. Experimentally measuring equilibrium dynamics is a challenging problem that is at the forefront of chemical research. This review describes ultrafast 2D IR vibrational echo chemical exchange experiments and applies them to several types of molecular systems. The formation and dissociation of organic solute-solvent complexes are directly observed. The dissociation times of 13 complexes, ranging from 4 ps to 140 ps, are shown to obey a relationship that depends on the complex's formation enthalpy. The rate of rotational gauche-trans isomerization around a carbon-carbon single bond is determined for a substituted ethane at room temperature in a low viscosity solvent. The results are used to obtain an approximate isomerization rate for ethane. Finally, the time dependence of a well-defined single structural transformation of a protein is measured.

  15. Induction of natural competence in Streptococcus pneumoniae triggers lysis and DNA release from a subfraction of the cell population.

    PubMed

    Steinmoen, Hilde; Knutsen, Eivind; Håvarstein, Leiv Sigve

    2002-05-28

    Naturally competent bacteria have the ability to take up free DNA from the surrounding medium and incorporate this DNA into their genomes by homologous recombination. In naturally competent Streptococcus pneumoniae, and related streptococcal species from the mitis phylogenetic group, the competent state is not a constitutive property but is induced by a peptide pheromone through a quorum-sensing mechanism. Recent studies have shown that natural genetic transformation is an important mechanism for gene exchange between streptococci in nature. A prerequisite for effective gene exchange is the presence of streptococcal donor DNA in the environment. Despite decades of study of the transformation process we still do not know how this donor DNA is released from streptococcal cells to the external milieu. Traditionally, it has been assumed that donor DNA originates from cells that die and fall apart from natural causes. In this study we show that induction of the competent state initiates release of DNA from a subfraction of the bacterial population, probably by cell lysis. The majority of the cells induced to competence take up DNA and act as recipients, whereas the rest release DNA and act as donors. These findings show that natural transformation in streptococci provides a natural mechanism for genetic recombination that resembles sex in higher organisms.

  16. A hydrogeomorphic river network model predicts where and why hyporheic exchange is important in large basins

    USGS Publications Warehouse

    Gomez-Velez, Jesus D.; Harvey, Judson

    2014-01-01

    Hyporheic exchange has been hypothesized to have basin-scale consequences; however, predictions throughout river networks are limited by available geomorphic and hydrogeologic data and by models that can analyze and aggregate hyporheic exchange flows across large spatial scales. We developed a parsimonious but physically based model of hyporheic flow for application in large river basins: Networks with EXchange and Subsurface Storage (NEXSS). We applied NEXSS across a broad range of geomorphic diversity in river reaches and synthetic river networks. NEXSS demonstrates that vertical exchange beneath submerged bed forms rather than lateral exchange through meanders dominates hyporheic fluxes and turnover rates along river corridors. Per kilometer, low-order streams have a biogeochemical potential at least 2 orders of magnitude larger than higher-order streams. However, when biogeochemical potential is examined per average length of each stream order, low- and high-order streams were often found to be comparable. As a result, the hyporheic zone's intrinsic potential for biogeochemical transformations is comparable across different stream orders, but the greater river miles and larger total streambed area of lower order streams result in the highest cumulative impact from low-order streams. Lateral exchange through meander banks may be important in some cases but generally only in large rivers.

  17. A hydrogeomorphic river network model predicts where and why hyporheic exchange is important in large basins

    NASA Astrophysics Data System (ADS)

    Gomez-Velez, Jesus D.; Harvey, Judson W.

    2014-09-01

    Hyporheic exchange has been hypothesized to have basin-scale consequences; however, predictions throughout river networks are limited by available geomorphic and hydrogeologic data and by models that can analyze and aggregate hyporheic exchange flows across large spatial scales. We developed a parsimonious but physically based model of hyporheic flow for application in large river basins: Networks with EXchange and Subsurface Storage (NEXSS). We applied NEXSS across a broad range of geomorphic diversity in river reaches and synthetic river networks. NEXSS demonstrates that vertical exchange beneath submerged bed forms rather than lateral exchange through meanders dominates hyporheic fluxes and turnover rates along river corridors. Per kilometer, low-order streams have a biogeochemical potential at least 2 orders of magnitude larger than higher-order streams. However, when biogeochemical potential is examined per average length of each stream order, low- and high-order streams were often found to be comparable. As a result, the hyporheic zone's intrinsic potential for biogeochemical transformations is comparable across different stream orders, but the greater river miles and larger total streambed area of lower order streams result in the highest cumulative impact from low-order streams. Lateral exchange through meander banks may be important in some cases but generally only in large rivers.

  18. Disruptive Potential of the Internet to Transform Illicit Drug Markets and Impact on Future Patterns of Drug Consumption.

    PubMed

    Griffiths, P; Mounteney, J

    2017-02-01

    The internet facilitates rapid and covert communication, knowledge transfer, and has the potential to disrupt and transform drug market models and associated consumption patterns. Innovation and new trends diffuse rapidly through this medium and new operational models are emerging. Although the online drug markets currently only account for a small share of all drug transactions, the potential of the surface and deep web to provide a new platform for drug sale and exchanges is considerable. © 2016 American Society for Clinical Pharmacology and Therapeutics.

  19. Turn exchange rhythm in English dialogues

    NASA Astrophysics Data System (ADS)

    Fon, Janice

    2005-09-01

    This study looked at the relationship between rhythm and exchange type in British English, a stress-timed language, and Singaporean English, a syllable-timed language, using a spontaneous speech corpus. Exchange intervals (EIs), or the time difference between the end of one speaker and the beginning of another, were measured and exchanges of different types were labeled. Results showed that, in a dialogue, EIs were generally limited to a narrow range. However, within this range, EIs had at least four functions. First, EIs were reflective of the cognitive load and functioned as a way to differentiate various exchange types. Those requiring more cognitive resources, such as question-and-answer pairs, generally needed longer EIs than those not as cognitively loaded, such as backchanneling pairs. Second, EIs were indicative of linguistic rhythm. Singaporean English tended to have shorter EIs than British English. Third, EIs were reflective of politeness. The degree of politeness correlated negatively with EI. Shorter EIs showed a higher degree of respect. Finally, EIs were also indicative of the level of insecurity of a speaker, which was best reflected by gender differences. Females in general had longer EIs than males.

  20. Introducing False EUR and False EUR exchange rates

    NASA Astrophysics Data System (ADS)

    Ausloos, M.; Ivanova, K.

    2000-10-01

    The Euro ( EUR) is a new currency introduced by the European Community. Its exchange rate is very puzzling. We have invented a false Euro ( FEUR) dating back to 1993 and have derived the exchange rates of the FEUR with respect to currencies not belonging to the EUR, i.e., DKK, CHF, JPY and USD. This allows us to search for correlations between the fluctuations preexisting to the introduction of EUR and present ones in such financial data. The detrended fluctuation analysis ( DFA) statistical method is used. This leads to assume a power-law behavior, i.e., a scaling hypothesis, through an exponent α. The latter has demonstrated its usefulness for the investigations of long-range power-law correlations in several types of financial sequences. Our findings show that the α exponent interestingly characterizes fractional Brownian motion of the currency exchange rates between EUR and DKK over a 25 day interval, and usual Brownian motion otherwise and for the three other investigated exchange rates. We can devise an investment strategy based on the localα technique and obtain appreciable gains for the time being.

  1. In Situ Tracking Kinetic Pathways of Li + /Na + Substitution during Ion-Exchange Synthesis of Li xNa 1.5–x VOPO 4 F 0.5

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Park, Young-Uk; Bai, Jianming; Wang, Liping

    Ion exchange is a ubiquitous phenomenon central to wide industrial applications, ranging from traditional (bio)chemical separation to the emerging chimie douce synthesis of materials for batteries and other energy applications. The exchange process is complex, involving substitution and transport of different ions under non-equilibrium conditions, and thus difficult to probe, leaving a gap in mechanistic understanding of kinetic exchange pathways toward final products. Herein, we report in situ tracking kinetic pathways of Li +/Na + substitution during solvothermal ion-exchange synthesis of Li xNa 1.5-xVOPO 4F 0.5 (0 ≤ x ≤ 1.5), a promising multi-Li polyanionic cathode for batteries. The real-timemore » observation, corroborated by first-principles calculations, reveals a selective replacement of Na + by Li +, leading to peculiar Na +/Li +/vacancy orderings in the intermediates. Contradicting the traditional belief of facile topotactic substitution via solid solution reaction, an abrupt two-phase transformation occurs and predominantly governs the kinetics of ion exchange and transport in the 1D polyanionic framework, consequently leading to significant difference of Li stoichiometry and electrochemical properties in the exchanged products. The findings may help to pave the way for rational design of ion exchange synthesis for making new materials.« less

  2. In Situ Tracking Kinetic Pathways of Li + /Na + Substitution during Ion-Exchange Synthesis of Li xNa 1.5–x VOPO 4 F 0.5

    DOE PAGES

    Park, Young-Uk; Bai, Jianming; Wang, Liping; ...

    2017-08-29

    Ion exchange is a ubiquitous phenomenon central to wide industrial applications, ranging from traditional (bio)chemical separation to the emerging chimie douce synthesis of materials for batteries and other energy applications. The exchange process is complex, involving substitution and transport of different ions under non-equilibrium conditions, and thus difficult to probe, leaving a gap in mechanistic understanding of kinetic exchange pathways toward final products. Herein, we report in situ tracking kinetic pathways of Li +/Na + substitution during solvothermal ion-exchange synthesis of Li xNa 1.5-xVOPO 4F 0.5 (0 ≤ x ≤ 1.5), a promising multi-Li polyanionic cathode for batteries. The real-timemore » observation, corroborated by first-principles calculations, reveals a selective replacement of Na + by Li +, leading to peculiar Na +/Li +/vacancy orderings in the intermediates. Contradicting the traditional belief of facile topotactic substitution via solid solution reaction, an abrupt two-phase transformation occurs and predominantly governs the kinetics of ion exchange and transport in the 1D polyanionic framework, consequently leading to significant difference of Li stoichiometry and electrochemical properties in the exchanged products. The findings may help to pave the way for rational design of ion exchange synthesis for making new materials.« less

  3. Nonuniform sampling and non-Fourier signal processing methods in multidimensional NMR.

    PubMed

    Mobli, Mehdi; Hoch, Jeffrey C

    2014-11-01

    Beginning with the introduction of Fourier Transform NMR by Ernst and Anderson in 1966, time domain measurement of the impulse response (the free induction decay, FID) consisted of sampling the signal at a series of discrete intervals. For compatibility with the discrete Fourier transform (DFT), the intervals are kept uniform, and the Nyquist theorem dictates the largest value of the interval sufficient to avoid aliasing. With the proposal by Jeener of parametric sampling along an indirect time dimension, extension to multidimensional experiments employed the same sampling techniques used in one dimension, similarly subject to the Nyquist condition and suitable for processing via the discrete Fourier transform. The challenges of obtaining high-resolution spectral estimates from short data records using the DFT were already well understood, however. Despite techniques such as linear prediction extrapolation, the achievable resolution in the indirect dimensions is limited by practical constraints on measuring time. The advent of non-Fourier methods of spectrum analysis capable of processing nonuniformly sampled data has led to an explosion in the development of novel sampling strategies that avoid the limits on resolution and measurement time imposed by uniform sampling. The first part of this review discusses the many approaches to data sampling in multidimensional NMR, the second part highlights commonly used methods for signal processing of such data, and the review concludes with a discussion of other approaches to speeding up data acquisition in NMR. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Dynamical behaviors of inter-out-of-equilibrium state intervals in Korean futures exchange markets

    NASA Astrophysics Data System (ADS)

    Lim, Gyuchang; Kim, SooYong; Kim, Kyungsik; Lee, Dong-In; Scalas, Enrico

    2008-05-01

    A recently discovered feature of financial markets, the two-phase phenomenon, is utilized to categorize a financial time series into two phases, namely equilibrium and out-of-equilibrium states. For out-of-equilibrium states, we analyze the time intervals at which the state is revisited. The power-law distribution of inter-out-of-equilibrium state intervals is shown and we present an analogy with discrete-time heat bath dynamics, similar to random Ising systems. In the mean-field approximation, this model reduces to a one-dimensional multiplicative process. By varying global and local model parameters, the relevance between volatilities in financial markets and the interaction strengths between agents in the Ising model are investigated and discussed.

  5. Real-time observation of cation exchange kinetics and dynamics at the muscovite-water interface

    DOE PAGES

    Lee, Sang Soo; Fenter, Paul; Nagy, Kathryn L.; ...

    2017-06-09

    Here, ion exchange at charged solid–liquid interfaces is central to a broad range of chemical and transport phenomena. Real-time observations of adsorption/desorption at the molecular-scale elucidate exchange reaction pathways. Here, we report temporal variation in the distribution of Rb + species at the muscovite (001)–water interface during exchange with Na +. Time-resolved resonant anomalous X-ray reflectivity measurements reveal that Rb + desorption occurs over several tens of seconds during which thermodynamically stable inner-sphere Rb + slowly transforms to less stable outer-sphere Rb + at 25°C. In contrast, Rb + adsorption is about twice as fast, proceeding quickly from Rb +more » in the bulk solution to the stable inner-sphere species. The Arrhenius plot of the adsorption/desorption rate constants measured from 9 to 55°C shows that the pre-exponential factor for desorption is significantly smaller than for adsorption, indicating that this reduced attempt frequency of cation detachment largely explains the slow cation exchange processes at the interface.« less

  6. Characterization of Colloidal Quantum Dot Ligand Exchange by X-ray Photoelectron Spectroscopy

    NASA Astrophysics Data System (ADS)

    Atewologun, Ayomide; Ge, Wangyao; Stiff-Roberts, Adrienne D.

    2013-05-01

    Colloidal quantum dots (CQDs) are chemically synthesized semiconductor nanoparticles with size-dependent wavelength tunability. Chemical synthesis of CQDs involves the attachment of long organic surface ligands to prevent aggregation; however, these ligands also impede charge transport. Therefore, it is beneficial to exchange longer surface ligands for shorter ones for optoelectronic devices. Typical characterization techniques used to analyze surface ligand exchange include Fourier-transform infrared spectroscopy, x-ray diffraction, transmission electron microscopy, and nuclear magnetic resonance spectroscopy, yet these techniques do not provide a simultaneously direct, quantitative, and sensitive method for evaluating surface ligands on CQDs. In contrast, x-ray photoelectron spectroscopy (XPS) can provide nanoscale sensitivity for quantitative analysis of CQD surface ligand exchange. A unique aspect of this work is that a fingerprint is identified for shorter surface ligands by resolving the regional XPS spectrum corresponding to different types of carbon bonds. In addition, a deposition technique known as resonant infrared matrix-assisted pulsed laser evaporation is used to improve the CQD film uniformity such that stronger XPS signals are obtained, enabling more accurate analysis of the ligand exchange process.

  7. Rapid Screening for Potential Epitopes Reactive with a Polycolonal Antibody by Solution-Phase H/D Exchange Monitored by FT-ICR Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Noble, Kyle A.; Mao, Yuan; Young, Nicolas L.; Sathe, Shridhar K.; Roux, Kenneth H.; Marshall, Alan G.

    2013-07-01

    The potential epitopes of a recombinant food allergen protein, cashew Ana o 2, reactive to polyclonal antibodies, were mapped by solution-phase amide backbone H/D exchange (HDX) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Ana o 2 polyclonal antibodies were purified in the serum from a goat immunized with cashew nut extract. Antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen:polyclonal antibody (Ag:pAb) complexes. Complexed and uncomplexed (free) rAna o 2 were then subjected to HDX-MS analysis. Four regions protected from H/D exchange upon pAb binding are identified as potential epitopes and mapped onto a homologous model.

  8. Solution of the Fokker-Planck equation with mixing of angular harmonics by beam-beam charge exchange

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mikkelsen, D.R.

    1989-09-01

    A method for solving the linear Fokker-Planck equation with anisotropic beam-beam charge exchange loss is presented. The 2-D equation is transformed to a system of coupled 1-D equations which are solved iteratively as independent equations. Although isotropic approximations to the beam-beam losses lead to inaccurate fast ion distributions, typically only a few angular harmonics are needed to include accurately the effect of the beam-beam charge exchange loss on the usual integrals of the fast ion distribution. Consequently, the algorithm converges very rapidly and is much more efficient than a 2-D finite difference method. A convenient recursion formula for the couplingmore » coefficients is given and generalization of the method is discussed. 13 refs., 2 figs.« less

  9. QUESP and QUEST revisited - fast and accurate quantitative CEST experiments.

    PubMed

    Zaiss, Moritz; Angelovski, Goran; Demetriou, Eleni; McMahon, Michael T; Golay, Xavier; Scheffler, Klaus

    2018-03-01

    Chemical exchange saturation transfer (CEST) NMR or MRI experiments allow detection of low concentrated molecules with enhanced sensitivity via their proton exchange with the abundant water pool. Be it endogenous metabolites or exogenous contrast agents, an exact quantification of the actual exchange rate is required to design optimal pulse sequences and/or specific sensitive agents. Refined analytical expressions allow deeper insight and improvement of accuracy for common quantification techniques. The accuracy of standard quantification methodologies, such as quantification of exchange rate using varying saturation power or varying saturation time, is improved especially for the case of nonequilibrium initial conditions and weak labeling conditions, meaning the saturation amplitude is smaller than the exchange rate (γB 1  < k). The improved analytical 'quantification of exchange rate using varying saturation power/time' (QUESP/QUEST) equations allow for more accurate exchange rate determination, and provide clear insights on the general principles to execute the experiments and to perform numerical evaluation. The proposed methodology was evaluated on the large-shift regime of paramagnetic chemical-exchange-saturation-transfer agents using simulated data and data of the paramagnetic Eu(III) complex of DOTA-tetraglycineamide. The refined formulas yield improved exchange rate estimation. General convergence intervals of the methods that would apply for smaller shift agents are also discussed. Magn Reson Med 79:1708-1721, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  10. Studying links between the Timing of Puberty and Psychological Individuation.

    ERIC Educational Resources Information Center

    Weichold, Karina; Silbereisen, Rainer K.; Schmitt-Rodermund, Eva

    Individuation is the process whereby adolescents gradually gain autonomy from their parents while maintaining emotional relatedness, accompanied by a transformation of the parent-child relationship. In everyday parent-child interactions, higher levels of individuation are displayed by characteristic styles of verbal exchanges, such as flexible…

  11. Community-Based Service-Learning: Partnerships of Reciprocal Exchange?

    ERIC Educational Resources Information Center

    Hammersley, Laura

    2012-01-01

    Community-based service-learning (CBSL) integrates experiential learning and academic goals with organized activities designed to meet the objectives of community partners. CBSL has potential to enhance (1) academic learning, (2) foster civic responsibility, (3) develop life skills and (4) transform student attitudes. However, little research…

  12. Manure management effects on phosphorus biotransformations and losses in animal production

    USDA-ARS?s Scientific Manuscript database

    The bioactivity of manure P is highly dynamic and dependent on interactions with the reactive soil surface and biologically mediated transformations. Biological tools that combine ligand exchange and enzyme-mediated mineralization of organic P can mimic plants and microorganisms in their ways of acq...

  13. Absence of a dose-fractionation effect on neoplastic transformation induced by fission-spectrum neutrons in C3H 10T1/2 cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Saran, A.; Pazzaglia, S.; Coppola, M.

    1991-06-01

    We have investigated the effect of fission-spectrum neutron dose fractionation on neoplastic transformation of exponentially growing C3H 10T1/2 cells. Total doses of 10.8, 27, 54, and 108 cGy were given in single doses or in five equal fractions delivered at 24-h intervals in the biological channel of the RSV-TAPIRO reactor at CRE-Casaccia. Both cell inactivation and neoplastic transformation were more effectively induced by fission neutrons than by 250-kVp X rays. No significant effect on cell survival or neoplastic transformation was observed with split doses compared to single doses of fission-spectrum neutrons. Neutron RBE values relative to X rays determined frommore » data for survival and neoplastic transformation were comparable.« less

  14. Mental body transformation deficits in patients with chronic balance disorders.

    PubMed

    Allum, J H J; Langewitz, W; Sleptsova, M; Welge-Luessen, A; Honegger, F; Schatz, T H; Biner, C L; Maguire, C; Schmid, D A

    2017-01-01

    Movements may be generated consistent with imagining one's own body transformed or "disembodied" to a new position. Based on this concept we hypothesized that patients with objective balance deficits (obj-BD) would have altered neural transformation processes executing own body transformation (OBT) with functional consequences on balance control. Also we examined whether feeling unstable due to dizziness only (DO), without an obj-BD, also lead to an impaired OBT. 32 patients with chronic dizziness were tested: 16 patients with obj-BD as determined by balance control during a sequence of stance and gait tasks, 16 patients with dizziness only (DO). Patients and 9 healthy controls (HCs) were asked to replicate roll trunk movements of an instructor in a life size video: first, with spontaneously copied (SPO) or "embodied" egocentric movements (lean when the instructor leans); second, with "disembodied" or "transformed" movements (OBT) with exact replication - lean left when the instructor leans left. Onset latency of trunk roll, rise time to peak roll angle (interval), roll velocity, and amplitude were measured. SPO movements were always mirror-imaged. OBT task latencies were significantly longer and intervals shorter than for SPO tasks (p < 0.03) for all groups. Obj-BD but not DO patients had more errors for the OBT task and, compared to HCs, had longer onset latencies (p < 0.05) and smaller velocities (p < 0.003) and amplitudes (p < 0.001) in both the SPO and OBT tasks. Measures of DO patients were not significantly different from those of HCs. Mental transformation (OBT) and SPO copying abilities are impaired in subjects with obj-BD and dizziness, but not with dizziness only. We conclude that processing the neuropsychological representation of the human body (body schema) slows when balance control is deficient.

  15. Investigating the Role of Hydrologic Residence Time in Nitrogen Transformations at the Sediment-Water Interface using Controlled Variable Head Experiments

    NASA Astrophysics Data System (ADS)

    Hampton, T. B.; Zarnetske, J. P.; Briggs, M. A.; Singha, K.; Day-Lewis, F. D.

    2017-12-01

    Many important biogeochemical processes governing both carbon and nitrogen dynamics in streams take place at the sediment-water interface (SWI). This interface is highly variable in biogeochemical function, with stream stage often influencing the magnitude and direction of water and solute exchange through the SWI. It is well known that the SWI can be an important location for carbon and nitrogen transformations, including denitrification and greenhouse gas production. The degree of mixing of carbon and nitrate, along with oxygen from surface waters, is strongly influenced by hydrologic exchange at the SWI. We hypothesize that hydrologic residence time, which is also determined by the magnitude of exchange, is a key control on the fate of nitrate at the SWI and on the end products of denitrification. Previous studies in the headwaters of the Ipswich River in MA as part of the Lotic Intersite Nitrogen Experiments (LINX II) and other long-term monitoring suggest that the Ipswich River SWI represents an important source of nitrous oxide, a potent greenhouse gas. Using a novel constant-head infiltrometer ring embedded in the stream sediments, we created four unique controlled down-welling (i.e., recharge) conditions, and tested how varying this hydrologic flux and thus the residence time distribution influenced biogeochemical function of the Ipswich River SWI. Specifically, we added isotopically-labelled 15N-nitrate to stream water during each controlled hydrologic flux experiment to quantify nitrate transformation rates, including denitrification end products, under the different hydrologic conditions. We also measured a suite of carbon and nitrogen solutes, along with dissolved oxygen conditions throughout each experiment to characterize the broader residence timescale and biogeochemical responses to the hydrologic manipulations. Initial results show that the oxic conditions of the SWI were strongly responsive to changes in hydrologic flux rates, thereby changing the redox conditions and likely the fate of the nitrate through the infiltrometer. The forthcoming 15N data will quantify the nitrate response. Overall, this study will help demonstrate how the SWI of this historically important research river transforms nitrate under variable hydrologic conditions.

  16. Transition from an optical precursor in coupled-resonator-induced transparency to coherent energy exchange in Autler-Townes splitting

    NASA Astrophysics Data System (ADS)

    Oishi, Tohru; Suzuki, Ryuta; Talukder, Aminul I.; Tomita, Makoto

    2013-08-01

    We investigated the transient responses of coupled optical resonators, after they were injected with square modulated temporal pulses. A sharp spike, attributed to the optical precursor in coupled-resonator-induced transparency, appeared when the coupling between the resonators was weak. As the coupling strength increased, the resonance spectrum developed clearly separated double dips of Autler-Townes splitting, and the precursor spike transformed into an oscillatory structure. These temporal oscillations were attributed to the coherent energy exchange between two resonators. Theoretical calculations were in good agreement with the experimental observations.

  17. Disulphide bond exchange inhibited by air - kinetic and thermodynamic products in a library of macrocyclic cysteine derivatives.

    PubMed

    Cholewiak, Agnieszka; Dobrzycki, Łukasz; Jurczak, Janusz; Ulatowski, Filip

    2018-04-04

    In this paper we present the synthesis and reactivity of dithiols comprising of two cysteine moieties attached to a dipicolinic acid core. Oxidation of these thiols provides oligomeric macrocycles. Monomers with 13-membered rings are kinetic products which are, however, strained and readily transform into higher oligomers under basic conditions or elevated temperature via a disulphide exchange reaction. Dimers, which are the most stable thermodynamic products, equilibrate only under inert conditions with thiolate as a catalyst. Under aerobic conditions, the thiols are oxidised before the equilibrium is reached.

  18. Goddard Institute for Space Studies (GISS) 3-Dimensional (3-D) Global Tracer Transport Model (DB1006)

    DOE Data Explorer

    Fung, I.

    1993-01-01

    This directory contains the input files used in simulations of atmospheric CO2 using the GISS 3-D global tracer transport model. The directory contains 16 files including a help file (CO2FUNG.HLP), 12 files containing monthly exchanges with vegetation and soils (CO2VEG.JAN - DEC), 1 file containing releases of CO2 from fossil fuel burning (CO2FOS.MRL), 1 file containing releases of CO2 from land transformations (CO2DEF.HOU), and 1 file containing the patterns of CO2 exchange with the oceans (CO2OCN.TAK).

  19. Copper(I)-catalyzed substitution reactions of propargylic amines: importance of C(sp)-C(sp3) bond cleavage in generation of iminium intermediates.

    PubMed

    Sugiishi, Tsuyuka; Kimura, Akifumi; Nakamura, Hiroyuki

    2010-04-21

    Substitution reactions of propargylic amines proceed in the presence of copper(I) catalysts. Mechanistic studies showed that C(sp)-C(sp(3)) bond cleavage assisted by nitrogen lone-pair electrons is essential for the reaction, and the resulting iminium intermediates undergo amine exchange, aldehyde exchange, and alkyne addition reactions. Because iminium intermediates are key to aldehyde-alkyne-amine (A(3)) coupling reactions, this transformation is effective not only for reconstruction of propargylic amines but also for chiral induction of racemic compounds in the presence of chiral catalysts.

  20. The pricing of European options on two underlying assets with delays

    NASA Astrophysics Data System (ADS)

    Lin, Lisha; Li, Yaqiong; Wu, Jing

    2018-04-01

    In the paper, the pricing of European options on two underlying assets with delays is discussed. By using the approach of equivalent martingale measure transformation, the market is proved to be complete. With exchange option as a particular example, we obtain the explicit pricing formula in a subinterval of option period. The robust Euler-Maruyama method is combined with the Monte Carlo simulation to compute exchange option prices within the whole option period. Numerical experiments indicate that there is an increasing possibility of the difference between the delayed and Black-Scholes option prices with the increase of delay.

  1. 47 CFR 52.103 - Lag times.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Lag times. 52.103 Section 52.103... Free Numbers § 52.103 Lag times. (a) Definitions. As used in this section, the following definitions... and an exchange carrier intercept recording is being provided. (3) Lag Time. The interval between a...

  2. 47 CFR 52.103 - Lag times.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Lag times. 52.103 Section 52.103... Free Numbers § 52.103 Lag times. (a) Definitions. As used in this section, the following definitions... and an exchange carrier intercept recording is being provided. (3) Lag Time. The interval between a...

  3. 47 CFR 52.103 - Lag times.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Lag times. 52.103 Section 52.103... Free Numbers § 52.103 Lag times. (a) Definitions. As used in this section, the following definitions... and an exchange carrier intercept recording is being provided. (3) Lag Time. The interval between a...

  4. 47 CFR 52.103 - Lag times.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Lag times. 52.103 Section 52.103... Free Numbers § 52.103 Lag times. (a) Definitions. As used in this section, the following definitions... and an exchange carrier intercept recording is being provided. (3) Lag Time. The interval between a...

  5. Population-based Incidence of Intraocular Lens Exchange in Olmsted County, Minnesota.

    PubMed

    Bothun, Erick D; Cavalcante, Lilian C B; Hodge, David O; Patel, Sanjay V

    2018-03-01

    To determine the population-based incidence of pseudophakic intraocular lens exchange in Olmsted County, Minnesota. Retrospective review of a population-based cohort. Patients undergoing pseudophakic intraocular lens exchange in Olmsted County, Minnesota, between January 1, 1986 and December 31, 2016 were identified from the Rochester Epidemiology Project medical record linkage system. Indications and outcomes were determined, and the incidence rate was calculated as cases per 1 000 000 person-years. Poisson regression analysis was used to assess changes in incidence over time, and the cumulative probability of needing a lens exchange was estimated by Kaplan-Meier analysis. Eighty cases of intraocular lens exchange were identified, yielding an overall age- and sex-adjusted incidence rate of 28.4 per million (confidence interval [CI], 22.1-34.7), which increased over the study period (P = .04). The 30-year cumulative probability of intraocular lens exchange among patients undergoing cataract surgery was 1.5% (CI, 0.6%-2.4%), increasing at a relatively constant rate. Dislocated lenses accounted for 72.5% of lens exchanges. Unplanned refractive outcome of primary cataract surgery and uveitis-glaucoma-hyphema syndrome from squared-edged haptics emerged as newer indications for intraocular lens exchange. The population-based incidence of pseudophakic intraocular lens exchange has increased over the last 30 years, and can be explained by the increase in incidence rate of cataract surgery over the same period. Surgeons should be aware of emerging indications of intraocular lens exchange, which reflect changes in lens design and increasing expectations of refractive outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Effect of plasma exchange on in-hospital mortality in patients with pulmonary hemorrhage secondary to antineutrophil cytoplasmic antibody-associated vasculitis: A propensity-matched analysis using a nationwide administrative database.

    PubMed

    Uechi, Eishi; Okada, Masato; Fushimi, Kiyohide

    2018-01-01

    Secondary pulmonary hemorrhage increases the risk of mortality in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV); plasma exchange therapy may improve outcomes in these patients. We conducted a retrospective cohort study to investigate the effect of plasma exchange therapy on short-term prognoses in patients with pulmonary hemorrhage secondary to AAV. This study utilized the Diagnosis Procedure Combination database, which is a nationwide inpatient database in Japan. We checked the abstract data and medical actions and identified the patients with pulmonary hemorrhage secondary to AAV who required proactive treatment between 2009 and 2014. To compare the in-hospital mortality, we performed propensity score matching between the plasma exchange and non-plasma exchange groups at a ratio of 1:1. Of the 52,932 patients with AAV, 940 developed pulmonary hemorrhage as a complication. A total of 249 patients from 194 hospitals were eligible for the study. Propensity score matching at a ratio of 1:1 was performed, and 59 pairs were formed (plasma exchange group, n = 59; non-plasma exchange group, n = 59). A statistically significant difference was found in the all-cause in-hospital mortality between the plasma exchange and non-plasma exchange groups (35.6% vs. 54.2%; p = 0041; risk difference, -18.6; 95% confidence interval (CI), -35.4% to -0.67%). Thus, plasma exchange therapy was associated with improved in-hospital mortality in patients with pulmonary hemorrhage secondary to AAV.

  7. Risk of Venous Thromboembolism Following Peripherally Inserted Central Catheter Exchange: An Analysis of 23,000 Hospitalized Patients.

    PubMed

    Chopra, Vineet; Kaatz, Scott; Grant, Paul; Swaminathan, Lakshmi; Boldenow, Tanya; Conlon, Anna; Bernstein, Steven J; Flanders, Scott A

    2018-02-01

    Catheter exchange over a guidewire is frequently performed for malfunctioning peripherally inserted central catheters (PICCs). Whether such exchanges are associated with venous thromboembolism is not known. We performed a retrospective cohort study to assess the association between PICC exchange and risk of thromboembolism. Adult hospitalized patients that received a PICC during clinical care at one of 51 hospitals participating in the Michigan Hospital Medicine Safety consortium were included. The primary outcome was hazard of symptomatic venous thromboembolism (radiographically confirmed upper-extremity deep vein thrombosis and pulmonary embolism) in those that underwent PICC exchange vs those that did not. Of 23,010 patients that underwent PICC insertion in the study, 589 patients (2.6%) experienced a PICC exchange. Almost half of all exchanges were performed for catheter dislodgement or occlusion. A total of 480 patients (2.1%) experienced PICC-associated deep vein thrombosis. The incidence of deep vein thrombosis was greater in those that underwent PICC exchange vs those that did not (3.6% vs 2.0%, P < .001). Median time to thrombosis was shorter among those that underwent exchange vs those that did not (5 vs 11 days, P = .02). Following adjustment, PICC exchange was independently associated with twofold greater risk of thrombosis (hazard ratio [HR] 1.98; 95% confidence interval [CI], 1.37-2.85) vs no exchange. The effect size of PICC exchange on thrombosis was second in magnitude to device lumens (HR 2.06; 95% CI, 1.59-2.66 and HR 2.31; 95% CI, 1.6-3.33 for double- and triple-lumen devices, respectively). Guidewire exchange of PICCs may be associated with increased risk of thrombosis. As some exchanges may be preventable, consideration of risks and benefits of exchanges in clinical practice is needed. Published by Elsevier Inc.

  8. The parallel algorithm for the 2D discrete wavelet transform

    NASA Astrophysics Data System (ADS)

    Barina, David; Najman, Pavel; Kleparnik, Petr; Kula, Michal; Zemcik, Pavel

    2018-04-01

    The discrete wavelet transform can be found at the heart of many image-processing algorithms. Until now, the transform on general-purpose processors (CPUs) was mostly computed using a separable lifting scheme. As the lifting scheme consists of a small number of operations, it is preferred for processing using single-core CPUs. However, considering a parallel processing using multi-core processors, this scheme is inappropriate due to a large number of steps. On such architectures, the number of steps corresponds to the number of points that represent the exchange of data. Consequently, these points often form a performance bottleneck. Our approach appropriately rearranges calculations inside the transform, and thereby reduces the number of steps. In other words, we propose a new scheme that is friendly to parallel environments. When evaluating on multi-core CPUs, we consistently overcome the original lifting scheme. The evaluation was performed on 61-core Intel Xeon Phi and 8-core Intel Xeon processors.

  9. Transformation of fraud activities in procurement system in Indonesia

    NASA Astrophysics Data System (ADS)

    Setiani, N.; Huda, S. N.; Pulungan, R.; Winarko, E.

    2017-03-01

    E-procurement has been applied in Indonesia since 2008 through the adoption of Electronic Procurement System (SPSE). The purpose of the use of SPSE in the procurement process is to improve the efficiency of goods or services procurement. In the bidding process, intensive communication and data exchange between providers and organizers are urgently needed. Through SPSE, the frequency of face to face meetings between providers and the committee can be reduced. This is expected to minimize potential fraud behaviors in the goods or services procurement conducted through the tender process. There exists a transformation of activities in the procurement through SPSE from the tender process that was previously done manually. In this paper, we analyze this transformation between manual procurement process and SPSE-based procurement process. The result of the analysis is exploited for investigating the possibility of fraud behavior transformations in every phase of e-procurement activities.

  10. Heat storage in alloy transformations

    NASA Technical Reports Server (NTRS)

    Birchenall, C. E.; Gueceri, S. I.; Farkas, D.; Labdon, M. B.; Nagaswami, N.; Pregger, B.

    1981-01-01

    The feasibility of using metal alloys as thermal energy storage media was determined. The following major elements were studied: (1) identification of congruently transforming alloys and thermochemical property measurements; (2) development of a precise and convenient method for measuring volume change during phase transformation and thermal expansion coefficients; (3) development of a numerical modeling routine for calculating heat flow in cylindrical heat exchangers containing phase change materials; and (4) identification of materials that could be used to contain the metal alloys. Several eutectic alloys and ternary intermetallic phases were determined. A method employing X-ray absorption techniques was developed to determine the coefficients of thermal expansion of both the solid and liquid phases and the volume change during phase transformation from data obtained during one continuous experimental test. The method and apparatus are discussed and the experimental results are presented. The development of the numerical modeling method is presented and results are discussed for both salt and metal alloy phase change media.

  11. Causes of Phakic Implantable Collamer Lens Explantation/Exchange at King Khaled Eye Specialist Hospital

    PubMed Central

    AlSabaani, Nasser A.; Behrens, Ashley; Jastanieah, Sabah; Al Malki, Salem; Al Jindan, Mohanna; Al Motowa, Saeed

    2016-01-01

    PURPOSE: The purpose of this study is to evaluate the causes of phakic implantable collamer lens (ICL) explantation/exchange at an eye hospital in Saudi Arabia. MATERIALS AND METHODS: A retrospective chart review was performed for patients who underwent ICL implantation from 2007 to March 2014 and data were collected on cases that underwent ICL explantation. RESULTS: Of the 787 ICL implants, 30 implants (3.8% [95% confidence interval 2.6%; 5.3%]) were explanted. The causes of explantation included incorrect lens size (22), cataract (4), high residual astigmatism (2), rhegmatogenous retinal detachment (1), and intolerable glare (1). Corrective measures mainly included an exchange with an appropriately sized lens (9), ICL explantation (11), with phacoemulsification and posterior chamber intraocular lens implantation (6), or replacement with an ICL of correct power (2). CONCLUSION: Incorrect ICL size was the most common cause of ICL explantation. More accurate sizing methods for ICL are required to reduce the explantation/exchange rate. PMID:27994391

  12. Automated electrotransformation of Escherichia coli on a digital microfluidic platform using bioactivated magnetic beads.

    PubMed

    Moore, J A; Nemat-Gorgani, M; Madison, A C; Sandahl, M A; Punnamaraju, S; Eckhardt, A E; Pollack, M G; Vigneault, F; Church, G M; Fair, R B; Horowitz, M A; Griffin, P B

    2017-01-01

    This paper reports on the use of a digital microfluidic platform to perform multiplex automated genetic engineering (MAGE) cycles on droplets containing Escherichia coli cells. Bioactivated magnetic beads were employed for cell binding, washing, and media exchange in the preparation of electrocompetent cells in the electrowetting-on-dieletric (EWoD) platform. On-cartridge electroporation was used to deliver oligonucleotides into the cells. In addition to the optimization of a magnetic bead-based benchtop protocol for generating and transforming electrocompetent E. coli cells, we report on the implementation of this protocol in a fully automated digital microfluidic platform. Bead-based media exchange and electroporation pulse conditions were optimized on benchtop for transformation frequency to provide initial parameters for microfluidic device trials. Benchtop experiments comparing electrotransformation of free and bead-bound cells are presented. Our results suggest that dielectric shielding intrinsic to bead-bound cells significantly reduces electroporation field exposure efficiency. However, high transformation frequency can be maintained in the presence of magnetic beads through the application of more intense electroporation pulses. As a proof of concept, MAGE cycles were successfully performed on a commercial EWoD cartridge using variations of the optimal magnetic bead-based preparation procedure and pulse conditions determined by the benchtop results. Transformation frequencies up to 22% were achieved on benchtop; this frequency was matched within 1% (21%) by MAGE cycles on the microfluidic device. However, typical frequencies on the device remain lower, averaging 9% with a standard deviation of 9%. The presented results demonstrate the potential of digital microfluidics to perform complex and automated genetic engineering protocols.

  13. Automated electrotransformation of Escherichia coli on a digital microfluidic platform using bioactivated magnetic beads

    PubMed Central

    Moore, J. A.; Nemat-Gorgani, M.; Madison, A. C.; Punnamaraju, S.; Eckhardt, A. E.; Pollack, M. G.; Church, G. M.; Fair, R. B.; Horowitz, M. A.; Griffin, P. B.

    2017-01-01

    This paper reports on the use of a digital microfluidic platform to perform multiplex automated genetic engineering (MAGE) cycles on droplets containing Escherichia coli cells. Bioactivated magnetic beads were employed for cell binding, washing, and media exchange in the preparation of electrocompetent cells in the electrowetting-on-dieletric (EWoD) platform. On-cartridge electroporation was used to deliver oligonucleotides into the cells. In addition to the optimization of a magnetic bead-based benchtop protocol for generating and transforming electrocompetent E. coli cells, we report on the implementation of this protocol in a fully automated digital microfluidic platform. Bead-based media exchange and electroporation pulse conditions were optimized on benchtop for transformation frequency to provide initial parameters for microfluidic device trials. Benchtop experiments comparing electrotransformation of free and bead-bound cells are presented. Our results suggest that dielectric shielding intrinsic to bead-bound cells significantly reduces electroporation field exposure efficiency. However, high transformation frequency can be maintained in the presence of magnetic beads through the application of more intense electroporation pulses. As a proof of concept, MAGE cycles were successfully performed on a commercial EWoD cartridge using variations of the optimal magnetic bead-based preparation procedure and pulse conditions determined by the benchtop results. Transformation frequencies up to 22% were achieved on benchtop; this frequency was matched within 1% (21%) by MAGE cycles on the microfluidic device. However, typical frequencies on the device remain lower, averaging 9% with a standard deviation of 9%. The presented results demonstrate the potential of digital microfluidics to perform complex and automated genetic engineering protocols. PMID:28191268

  14. ACCUMULATION OF ATMOSPHERIC MERCURY IN FOREST FOLIAGE. (R827622E02)

    EPA Science Inventory

    We used unique mesocosms to examine the role that plants play in accumulating and transforming atmospheric Hg. Several stands of quaking aspen were grown in large gas-exchange chambers in Hg-enriched soil (12.3±1.3 Transforming the Whole Class into Gossiping Groups.

    ERIC Educational Resources Information Center

    Baw, San Shwe

    2002-01-01

    Explores a way to use gossip in the language classroom to provide language fluency practice. Shows how certain interpersonal exchanges can be encouraged by exploiting the natural proclivity for talking about people. Activities stress social aspects of learning and are intended to provide learners with opportunities to talk and listen. (Author/VWL)

  15. Toward Projects in Humanization: Research on Co-Creating and Sustaining Dialogic Relationships

    ERIC Educational Resources Information Center

    San Pedro, Timothy; Kinloch, Valerie

    2017-01-01

    In this article, we argue that co-constructing knowledge, co-creating relationships, and exchanging stories are central to educational research. Relying on humanizing and Indigenous research methods to locate relational interactions in educational research allows us to engage in transformative praxis and storying, or Projects in Humanization…

  16. Blended Learning with International Students: A Multiliteracies Approach

    ERIC Educational Resources Information Center

    McPhee, Siobhán; Pickren, Graham

    2017-01-01

    While the use of information and communication technologies (ICTs) continues to transform learning, international migration and the increasing complexity of intercultural exchange and communication continue to do so as well. In this paper, we connect the dots and ask how ICTs can be used to enhance the learning experiences of international…

  17. Esterification of phenyl acetic acid with p-cresol using metal cation exchanged montmorillonite nanoclay catalysts

    PubMed Central

    Bhaskar, M.; Surekha, M.; Suma, N.

    2018-01-01

    The liquid phase esterification of phenyl acetic acid with p-cresol over different metal cation exchanged montmorillonite nanoclays yields p-cresyl phenyl acetate. Different metal cation exchanged montmorillonite nanoclays (Mn+ = Al3+, Zn2+, Mn2+, Fe3+, Cu2+) were prepared and the catalytic activity was studied. The esterification reaction was conducted by varying molar ratio of the reactants, reaction time and catalyst amount on the yield of the ester. Among the different metal cation exchanged catalysts used, Al3+-montmorillonite nanoclay was found to be more active. The characterization of the material used was studied under different techniques, namely X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. The product obtained, p-cresyl phenyl acetate, was identified by thin-layer chromotography and confirmed by Fourier transform infrared, 1H NMR and 13C NMR. The regeneration activity of used catalyst was also investigated up to fourth generation. PMID:29515855

  18. Spatially variable stage-driven groundwater-surface water interaction inferred from time-frequency analysis of distributed temperature sensing data

    USGS Publications Warehouse

    Mwakanyamale, Kisa; Slater, Lee; Day-Lewis, Frederick D.; Elwaseif, Mehrez; Johnson, Carole D.

    2012-01-01

    Characterization of groundwater-surface water exchange is essential for improving understanding of contaminant transport between aquifers and rivers. Fiber-optic distributed temperature sensing (FODTS) provides rich spatiotemporal datasets for quantitative and qualitative analysis of groundwater-surface water exchange. We demonstrate how time-frequency analysis of FODTS and synchronous river stage time series from the Columbia River adjacent to the Hanford 300-Area, Richland, Washington, provides spatial information on the strength of stage-driven exchange of uranium contaminated groundwater in response to subsurface heterogeneity. Although used in previous studies, the stage-temperature correlation coefficient proved an unreliable indicator of the stage-driven forcing on groundwater discharge in the presence of other factors influencing river water temperature. In contrast, S-transform analysis of the stage and FODTS data definitively identifies the spatial distribution of discharge zones and provided information on the dominant forcing periods (≥2 d) of the complex dam operations driving stage fluctuations and hence groundwater-surface water exchange at the 300-Area.

  19. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Sang Soo; Fenter, Paul; Nagy, Kathryn L.

    Here, ion exchange at charged solid–liquid interfaces is central to a broad range of chemical and transport phenomena. Real-time observations of adsorption/desorption at the molecular-scale elucidate exchange reaction pathways. Here, we report temporal variation in the distribution of Rb + species at the muscovite (001)–water interface during exchange with Na +. Time-resolved resonant anomalous X-ray reflectivity measurements reveal that Rb + desorption occurs over several tens of seconds during which thermodynamically stable inner-sphere Rb + slowly transforms to less stable outer-sphere Rb + at 25°C. In contrast, Rb + adsorption is about twice as fast, proceeding quickly from Rb +more » in the bulk solution to the stable inner-sphere species. The Arrhenius plot of the adsorption/desorption rate constants measured from 9 to 55°C shows that the pre-exponential factor for desorption is significantly smaller than for adsorption, indicating that this reduced attempt frequency of cation detachment largely explains the slow cation exchange processes at the interface.« less

  1. Synthesis of Silver Embedded Poly(o-Anisidine) Molybdophosphate Nano Hybrid Cation-Exchanger Applicable for Membrane Electrode

    PubMed Central

    Khan, Anish; Khan, Aftab Aslam Parwaz; Asiri, Abdullah M.; Rub, Malik Abdul

    2014-01-01

    Poly(o-anisidine) molybdophosphate was expediently obtained by sol-gel mixing of Poly(o-anisidine) into the inorganic matrices of molybdophosphate, which was allowed to react with silver nitrate to the formation of poly(o-anisidine) molybdophosphate embedded silver nano composite. The composite was characterized by Fourier Transform Infrared Spectroscopy, X-ray powder diffraction, UV-Vis Spectrophotometry, Fluorescence Spectroscopy, Scanning Electron Microscopy/Energy-dispersive X-ray Spectroscopy and Thermogravimertic Analysis. Ion exchange capacity and distribution studies were carried out to understand the ion-exchange capabilities of the nano composite. On the basis of highest distribution studies, this nano composite cation exchanger was used as preparation of heavy metal ion selective membrane. Membrane was characterized for its performance as porosity and swelling later on was used for the preparation of membrane electrode for Hg(II), having better linear range, wide working pH range (2–4.5) with fast response in the real environment. PMID:24805257

  2. A new neural network model for solving random interval linear programming problems.

    PubMed

    Arjmandzadeh, Ziba; Safi, Mohammadreza; Nazemi, Alireza

    2017-05-01

    This paper presents a neural network model for solving random interval linear programming problems. The original problem involving random interval variable coefficients is first transformed into an equivalent convex second order cone programming problem. A neural network model is then constructed for solving the obtained convex second order cone problem. Employing Lyapunov function approach, it is also shown that the proposed neural network model is stable in the sense of Lyapunov and it is globally convergent to an exact satisfactory solution of the original problem. Several illustrative examples are solved in support of this technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Quantum dot impregnated-chitosan film for heavy metal ion sensing and removal.

    PubMed

    Jaiswal, Amit; Ghsoh, Siddhartha Sankar; Chattopadhyay, Arun

    2012-11-06

    We report the use of biopolymer-stabilized ZnS quantum dots (Q-dots) for cation exchange reaction-based easy sensing and removal of heavy metal ions such as Hg(2+), Ag(+), and Pb(2+) in water. Chitosan-stabilized ZnS Q-dots were synthesized in aqueous medium and were observed to have been converted to HgS, Ag(2)S, and PbS Q-dots in the presence of corresponding ions. The transformed Q-dots showed characteristic color development, with Hg(2+) being exceptionally identifiable due to the visible bright yellow color formation, while brown coloration was observed in other metal ions. The cation exchange was driven by the difference in the solubility product of the reactant and the product Q-dots. The cation exchanged Q-dots preserved the morphology of the reactant Q-dots and displayed volume increase based on the bulk crystal lattice parameters. The band gap of the transformed Q-dots showed a major increase from the corresponding bulk band gap of the material, demonstrating the role of quantum confinement. Next, we fabricated ZnS Q-dot impregnated chitosan film which was used to remove heavy metal ions from contaminated water as measured using atomic absorption spectroscopy (AAS). The present system could suitably be used as a simple dipstick for elimination of heavy metal ion contamination in water.

  4. Is the "sterile cockpit" concept applicable to cardiovascular surgery critical intervals or critical events? The impact of protocol-driven communication during cardiopulmonary bypass.

    PubMed

    Wadhera, Rishi K; Parker, Sarah Henrickson; Burkhart, Harold M; Greason, Kevin L; Neal, James R; Levenick, Katherine M; Wiegmann, Douglas A; Sundt, Thoralf M

    2010-02-01

    There is general enthusiasm for applying strategies from aviation directly to medical care; the application of the "sterile cockpit" rule to surgery has accordingly been suggested. An implicit prerequisite to the evidence-based transfer of such a concept to the clinical domain, however, is definition of periods of high mental workload analogous to takeoff and landing. We measured cognitive demands among operating room staff, mapped critical events, and evaluated protocol-driven communication. With the National Aeronautics and Space Administration Task Load Index and semistructured focus groups, we identified common critical stages of cardiac surgical cases. Intraoperative communication was assessed before (n = 18) and after (n = 16) introduction of a structured communication protocol. Cognitive workload measures demonstrated high temporal diversity among caregivers in various roles. Eight critical events during cardiopulmonary bypass were then defined. A structured, unambiguous verbal communication protocol for these events was then implemented. Observations of 18 cases before implementation including 29.6 hours of cardiopulmonary bypass with 632 total communication exchanges (average 35.1 exchanges/case) were compared with observations of 16 cases after implementation including 23.9 hours of cardiopulmonary bypass with 748 exchanges (average 46.8 exchanges/case, P = .06). Frequency of communication breakdowns per case decreased significantly after implementation (11.5 vs 7.3 breakdowns/case, P = .008). Because of wide variations is cognitive workload among caregivers, effective communication can be structured around critical events rather than defined intervals analogous to the sterile cockpit, with reduction in communication breakdowns. 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  5. Associations between perceived crisis mode work climate and poor information exchange within hospitals.

    PubMed

    Patterson, Mark E; Bogart, Miller S; Starr, Kathleen R

    2015-03-01

    Because hospital units operating in crisis mode could create unsafe transitions of care due to miscommunication, our objective was to estimate associations between perceived crisis mode work climate and patient information exchange problems within hospitals. Self-reported data from 247,140 hospital staff members across 884 hospitals were obtained from the 2010 Hospital Survey on Patient Safety Culture. Presence of a crisis mode work climate was defined as respondents agreeing that the hospital unit in which they work tries to do too much too quickly. Presence of patient information exchange problems was defined as respondents agreeing that problems often occur in exchanging patient information across hospital units. Multivariable ordinal regressions estimated the likelihood of perceived problems in exchanging patient information across hospital units, controlling for perceived levels of crisis mode work climate, skill levels, work climate, and hospital infrastructure. Compared to those disagreeing, hospital staff members agreeing that the hospital unit in which they work tries to do too much too quickly were 1.6 times more likely to perceive problems in exchanging patient information across hospital units (odds ratio: 1.6, 95% confidence interval: 1.58-1.65). Hospital staff members perceiving crisis mode work climates within their hospital unit are more likely to perceive problems in exchanging patient information across units, underscoring the need to improve communication during transitions of care. © 2014 Society of Hospital Medicine.

  6. Elimination of current spikes in buck power converters

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T. (Inventor)

    1981-01-01

    Current spikes in a buck power converter due to commutating diode turn-off time are eliminated by using a tapped inductor in the converter with the tap connected to the switching transistor. The commutating diode is not in the usual place, but is instead connected to conduct current from one end of the tapped inductor remote from the load during the interval in which the transistor is not conducting. In the case of a converter having a center-tapped (primary and secondary) transformer between two switching power transistors operated in a push-pull mode and two rectifying diodes in the secondary circuit, current spikes due to transformer saturation are also eliminated by using a tapped inductor in the converter with the tap connected to the rectifying diodes and a diode connected to conduct current from one end of the tapped inductor remote from the load during the interval in which the transistors are not conducting.

  7. Derivation of the Lorentz force law, the magnetic field concept and the Faraday Lenz and magnetic Gauss laws using an invariant formulation of the Lorentz transformation

    NASA Astrophysics Data System (ADS)

    Field, J. H.

    2006-06-01

    It is demonstrated how the right-hand sides of the Lorentz transformation equations may be written, in a Lorentz-invariant manner, as 4-vector scalar products. This implies the existence of invariant length intervals analogous to invariant proper time intervals. An important distinction between the physical meanings of the space time and energy momentum 4-vectors is pointed out. The formalism is shown to provide a short derivation of the Lorentz force law of classical electrodynamics, and the conventional definition of the magnetic field, in terms of spatial derivatives of the 4-vector potential, as well as the Faraday Lenz law and the Gauss law for magnetic fields. The connection between the Gauss law for the electric field and the electrodynamic Ampère law, due to the 4-vector character of the electromagnetic potential, is also pointed out.

  8. Method for utilizing properties of the sinc(x) function for phase retrieval on nyquist-under-sampled data

    NASA Technical Reports Server (NTRS)

    Dean, Bruce H. (Inventor); Smith, Jeffrey Scott (Inventor); Aronstein, David L. (Inventor)

    2012-01-01

    Disclosed herein are systems, methods, and non-transitory computer-readable storage media for simulating propagation of an electromagnetic field, performing phase retrieval, or sampling a band-limited function. A system practicing the method generates transformed data using a discrete Fourier transform which samples a band-limited function f(x) without interpolating or modifying received data associated with the function f(x), wherein an interval between repeated copies in a periodic extension of the function f(x) obtained from the discrete Fourier transform is associated with a sampling ratio Q, defined as a ratio of a sampling frequency to a band-limited frequency, and wherein Q is assigned a value between 1 and 2 such that substantially no aliasing occurs in the transformed data, and retrieves a phase in the received data based on the transformed data, wherein the phase is used as feedback to an optical system.

  9. FungalBraid: A GoldenBraid-based modular cloning platform for the assembly and exchange of DNA elements tailored to fungal synthetic biology.

    PubMed

    Hernanz-Koers, Miguel; Gandía, Mónica; Garrigues, Sandra; Manzanares, Paloma; Yenush, Lynne; Orzaez, Diego; Marcos, Jose F

    2018-07-01

    Current challenges in the study and biotechnological exploitation of filamentous fungi are the optimization of DNA cloning and fungal genetic transformation beyond model fungi, the open exchange of ready-to-use and standardized genetic elements among the research community, and the availability of universal synthetic biology tools and rules. The GoldenBraid (GB) cloning framework is a Golden Gate-based DNA cloning system developed for plant synthetic biology through Agrobacterium tumefaciens-mediated genetic transformation (ATMT). In this study, we develop reagents for the adaptation of GB version 3.0 from plants to filamentous fungi through: (i) the expansion of the GB toolbox with the domestication of fungal-specific genetic elements; (ii) the design of fungal-specific GB structures; and (iii) the ATMT and gene disruption of the plant pathogen Penicillium digitatum as a proof of concept. Genetic elements domesticated into the GB entry vector pUPD2 include promoters, positive and negative selection markers and terminators. Interestingly, some GB elements can be directly exchanged between plants and fungi, as demonstrated with the marker hph for Hyg R or the fluorescent protein reporter YFP. The iterative modular assembly of elements generates an endless number of diverse transcriptional units and other higher order combinations in the pDGB3α/pDGB3Ω destination vectors. Furthermore, the original plant GB syntax was adapted here to incorporate specific GB structures for gene disruption through homologous recombination and dual selection. We therefore have successfully adapted the GB technology for the ATMT of fungi. We propose the name of FungalBraid (FB) for this new branch of the GB technology that provides open, exchangeable and collaborative resources to the fungal research community. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Relative Biological Effectiveness of HZE Particles for Chromosomal Exchanges and Other Surrogate Cancer Risk Endpoints.

    PubMed

    Cacao, Eliedonna; Hada, Megumi; Saganti, Premkumar B; George, Kerry A; Cucinotta, Francis A

    2016-01-01

    The biological effects of high charge and energy (HZE) particle exposures are of interest in space radiation protection of astronauts and cosmonauts, and estimating secondary cancer risks for patients undergoing Hadron therapy for primary cancers. The large number of particles types and energies that makeup primary or secondary radiation in HZE particle exposures precludes tumor induction studies in animal models for all but a few particle types and energies, thus leading to the use of surrogate endpoints to investigate the details of the radiation quality dependence of relative biological effectiveness (RBE) factors. In this report we make detailed RBE predictions of the charge number and energy dependence of RBE's using a parametric track structure model to represent experimental results for the low dose response for chromosomal exchanges in normal human lymphocyte and fibroblast cells with comparison to published data for neoplastic transformation and gene mutation. RBE's are evaluated against acute doses of γ-rays for doses near 1 Gy. Models that assume linear or non-targeted effects at low dose are considered. Modest values of RBE (<10) are found for simple exchanges using a linear dose response model, however in the non-targeted effects model for fibroblast cells large RBE values (>10) are predicted at low doses <0.1 Gy. The radiation quality dependence of RBE's against the effects of acute doses γ-rays found for neoplastic transformation and gene mutation studies are similar to those found for simple exchanges if a linear response is assumed at low HZE particle doses. Comparisons of the resulting model parameters to those used in the NASA radiation quality factor function are discussed.

  11. Relative Biological Effectiveness of HZE Particles for Chromosomal Exchanges and Other Surrogate Cancer Risk Endpoints

    DOE PAGES

    Cacao, Eliedonna; Hada, Megumi; Saganti, Premkumar B.; ...

    2016-04-25

    The biological effects of high charge and energy (HZE) particle exposures are of interest in space radiation protection of astronauts and cosmonauts, and estimating secondary cancer risks for patients undergoing Hadron therapy for primary cancers. The large number of particles types and energies that makeup primary or secondary radiation in HZE particle exposures precludes tumor induction studies in animal models for all but a few particle types and energies, thus leading to the use of surrogate endpoints to investigate the details of the radiation quality dependence of relative biological effectiveness (RBE) factors. In this report we make detailed RBE predictionsmore » of the charge number and energy dependence of RBE’s using a parametric track structure model to represent experimental results for the low dose response for chromosomal exchanges in normal human lymphocyte and fibroblast cells with comparison to published data for neoplastic transformation and gene mutation. RBE’s are evaluated against acute doses of γ-rays for doses near 1 Gy. Models that assume linear or non-targeted effects at low dose are considered. Modest values of RBE (<10) are found for simple exchanges using a linear dose response model, however in the non-targeted effects model for fibroblast cells large RBE values (>10) are predicted at low doses <0.1 Gy. The radiation quality dependence of RBE’s against the effects of acute doses γ-rays found for neoplastic transformation and gene mutation studies are similar to those found for simple exchanges if a linear response is assumed at low HZE particle doses. Finally, we discuss comparisons of the resulting model parameters to those used in the NASA radiation quality factor function.« less

  12. Relative Biological Effectiveness of HZE Particles for Chromosomal Exchanges and Other Surrogate Cancer Risk Endpoints

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cacao, Eliedonna; Hada, Megumi; Saganti, Premkumar B.

    The biological effects of high charge and energy (HZE) particle exposures are of interest in space radiation protection of astronauts and cosmonauts, and estimating secondary cancer risks for patients undergoing Hadron therapy for primary cancers. The large number of particles types and energies that makeup primary or secondary radiation in HZE particle exposures precludes tumor induction studies in animal models for all but a few particle types and energies, thus leading to the use of surrogate endpoints to investigate the details of the radiation quality dependence of relative biological effectiveness (RBE) factors. In this report we make detailed RBE predictionsmore » of the charge number and energy dependence of RBE’s using a parametric track structure model to represent experimental results for the low dose response for chromosomal exchanges in normal human lymphocyte and fibroblast cells with comparison to published data for neoplastic transformation and gene mutation. RBE’s are evaluated against acute doses of γ-rays for doses near 1 Gy. Models that assume linear or non-targeted effects at low dose are considered. Modest values of RBE (<10) are found for simple exchanges using a linear dose response model, however in the non-targeted effects model for fibroblast cells large RBE values (>10) are predicted at low doses <0.1 Gy. The radiation quality dependence of RBE’s against the effects of acute doses γ-rays found for neoplastic transformation and gene mutation studies are similar to those found for simple exchanges if a linear response is assumed at low HZE particle doses. Finally, we discuss comparisons of the resulting model parameters to those used in the NASA radiation quality factor function.« less

  13. Bacterial gene transfer by natural genetic transformation in the environment.

    PubMed Central

    Lorenz, M G; Wackernagel, W

    1994-01-01

    Natural genetic transformation is the active uptake of free DNA by bacterial cells and the heritable incorporation of its genetic information. Since the famous discovery of transformation in Streptococcus pneumoniae by Griffith in 1928 and the demonstration of DNA as the transforming principle by Avery and coworkers in 1944, cellular processes involved in transformation have been studied extensively by in vitro experimentation with a few transformable species. Only more recently has it been considered that transformation may be a powerful mechanism of horizontal gene transfer in natural bacterial populations. In this review the current understanding of the biology of transformation is summarized to provide the platform on which aspects of bacterial transformation in water, soil, and sediments and the habitat of pathogens are discussed. Direct and indirect evidence for gene transfer routes by transformation within species and between different species will be presented, along with data suggesting that plasmids as well as chromosomal DNA are subject to genetic exchange via transformation. Experiments exploring the prerequisites for transformation in the environment, including the production and persistence of free DNA and factors important for the uptake of DNA by cells, will be compiled, as well as possible natural barriers to transformation. The efficiency of gene transfer by transformation in bacterial habitats is possibly genetically adjusted to submaximal levels. The fact that natural transformation has been detected among bacteria from all trophic and taxonomic groups including archaebacteria suggests that transformability evolved early in phylogeny. Probable functions of DNA uptake other than gene acquisition will be discussed. The body of information presently available suggests that transformation has a great impact on bacterial population dynamics as well as on bacterial evolution and speciation. PMID:7968924

  14. Comparison of two adaptive temperature-based replica exchange methods applied to a sharp phase transition of protein unfolding-folding.

    PubMed

    Lee, Michael S; Olson, Mark A

    2011-06-28

    Temperature-based replica exchange (T-ReX) enhances sampling of molecular dynamics simulations by autonomously heating and cooling simulation clients via a Metropolis exchange criterion. A pathological case for T-ReX can occur when a change in state (e.g., folding to unfolding of a protein) has a large energetic difference over a short temperature interval leading to insufficient exchanges amongst replica clients near the transition temperature. One solution is to allow the temperature set to dynamically adapt in the temperature space, thereby enriching the population of clients near the transition temperature. In this work, we evaluated two approaches for adapting the temperature set: a method that equalizes exchange rates over all neighbor temperature pairs and a method that attempts to induce clients to visit all temperatures (dubbed "current maximization") by positioning many clients at or near the transition temperature. As a test case, we simulated the 57-residue SH3 domain of alpha-spectrin. Exchange rate equalization yielded the same unfolding-folding transition temperature as fixed-temperature ReX with much smoother convergence of this value. Surprisingly, the current maximization method yielded a significantly lower transition temperature, in close agreement with experimental observation, likely due to more extensive sampling of the transition state.

  15. Dependence and risk assessment for oil prices and exchange rate portfolios: A wavelet based approach

    NASA Astrophysics Data System (ADS)

    Aloui, Chaker; Jammazi, Rania

    2015-10-01

    In this article, we propose a wavelet-based approach to accommodate the stylized facts and complex structure of financial data, caused by frequent and abrupt changes of markets and noises. Specifically, we show how the combination of both continuous and discrete wavelet transforms with traditional financial models helps improve portfolio's market risk assessment. In the empirical stage, three wavelet-based models (wavelet-EGARCH with dynamic conditional correlations, wavelet-copula, and wavelet-extreme value) are considered and applied to crude oil price and US dollar exchange rate data. Our findings show that the wavelet-based approach provides an effective and powerful tool for detecting extreme moments and improving the accuracy of VaR and Expected Shortfall estimates of oil-exchange rate portfolios after noise is removed from the original data.

  16. Fe(+) chemical ionization of peptides.

    PubMed

    Speir, J P; Gorman, G S; Amster, I J

    1993-02-01

    Laser-desorbed peptide neutral molecules were allowed to react with Fe(+) in a Fourier transform mass spectrometer, using the technique of laser desorption/chemical ionization. The Fe(+) ions are formed by laser ablation of a steel target, as well as by dissociative charge-exchange ionization of ferrocene with Ne(+). Prior to reaction with laser-desorbed peptide molecules, Fe(+) ions undergo 20-100 thermalizin collisions with xenon to reduce the population of excited-state metal ion species. The Fe(+) ions that have not experienced thermalizing collisions undergo charge exchange with peptide molecules. Iron ions that undergo thermalizing collisions before they are allowed to react with peptides are found to undergo charge exchange and to form adduct species [M + Fe(+)] and fragment ions that result from the loss of small, stable molecules, such as H2O, CO, and CO2, from the metal ion-peptide complex.

  17. Intercalation of anionic organic ultraviolet ray absorbers into layered zinc hydroxide nitrate.

    PubMed

    Cursino, Ana Cristina Trindade; Gardolinski, José Eduardo Ferreira da Costa; Wypych, Fernando

    2010-07-01

    Layered zinc hydroxide nitrate (ZHN) was synthesized and nitrate ions were topotactically exchanged with three different anionic species of commercial organic ultraviolet (UV) ray absorbers: 2-mercaptobenzoic acid, 2-aminobenzoic acid, and 4-aminobenzoic acid. The exchange reactions were confirmed by X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), ultraviolet visible (UV-Vis) spectroscopy, and thermal analysis (thermogravimetry, TGA, and differential thermal analysis, DTA). In all the anionic exchanged products, evidence of grafting of the organic species onto the inorganic matrix was obtained. In general, after intercalation/grafting, the UV absorption ability was improved in relation to the use of the parent organic material, showing that layered hydroxide salts (LHS) can be good alternative matrixes for the immobilization of organic species with UV-blocking properties in cosmetic products. Copyright 2010 Elsevier Inc. All rights reserved.

  18. Application of Fourier transform infrared spectroscopy with chemometrics on postmortem interval estimation based on pericardial fluids.

    PubMed

    Zhang, Ji; Li, Bing; Wang, Qi; Wei, Xin; Feng, Weibo; Chen, Yijiu; Huang, Ping; Wang, Zhenyuan

    2017-12-21

    Postmortem interval (PMI) evaluation remains a challenge in the forensic community due to the lack of efficient methods. Studies have focused on chemical analysis of biofluids for PMI estimation; however, no reports using spectroscopic methods in pericardial fluid (PF) are available. In this study, Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance (ATR) accessory was applied to collect comprehensive biochemical information from rabbit PF at different PMIs. The PMI-dependent spectral signature was determined by two-dimensional (2D) correlation analysis. The partial least square (PLS) and nu-support vector machine (nu-SVM) models were then established based on the acquired spectral dataset. Spectral variables associated with amide I, amide II, COO - , C-H bending, and C-O or C-OH vibrations arising from proteins, polypeptides, amino acids and carbohydrates, respectively, were susceptible to PMI in 2D correlation analysis. Moreover, the nu-SVM model appeared to achieve a more satisfactory prediction than the PLS model in calibration; the reliability of both models was determined in an external validation set. The study shows the possibility of application of ATR-FTIR methods in postmortem interval estimation using PF samples.

  19. Removal of chromium (VI) from electroplating wastewater using an anion exchanger derived from rice straw.

    PubMed

    Cao, Wei; Dang, Zhi; Yia, Xiao-Yun; Yang, Chen; Lu, Gui-Ning; Liu, Yun-Feng; Huang, Se-Yan; Zheng, Liu-Chun

    2013-01-01

    An anion exchanger from rice straw was used to remove Cr (VI) from synthetic wastewater and electroplating effluent. The exchanger was characterized using Fourier transform infrared (FTIR) spectrum and scanning electron microscopy (SEM), and it was found that the quaternary amino group and hydroxyl group are the main functional groups on the fibrous surface of the exchanger. The effect of contact time, initial concentration and pH on the removal of Cr (VI), and adsorption isotherms at different temperature, was investigated. The results showed that the removal of Cr (VI) was very rapid and was significantly affected by the initial pH of the solution. Although acidic conditions (pH = 2-6) facilitated Cr (VI) adsorption, the exchanger was effective in neutral solution and even under weak base conditions. The equilibrium data fitted well with Langmuir adsorption model, and the maximum Cr (VI) adsorption capacities at pH 6.4 were 0.35, 0.36 and 0.38 mmol/g for 15, 25 and 35 degrees C, respectively. The exchanger was finally tested with real electroplating wastewater, and at sorbent dosage of 10 g/L, the removal efficiencies for Cr (VI) and total Cr were 99.4% and 97.8%, respectively. In addition, the positive relationship between adsorbed Cr (VI) and desorbed Cl- suggested that Cr (VI) was mainly removed by ion exchange with chlorine.

  20. Effects of High-Intensity Interval Training on Aerobic Capacity in Cardiac Patients: A Systematic Review with Meta-Analysis

    PubMed Central

    Xie, Bin; Yan, Xianfeng

    2017-01-01

    Purpose. The aim of this study was to compare the effects of high-intensity interval training (INTERVAL) and moderate-intensity continuous training (CONTINUOUS) on aerobic capacity in cardiac patients. Methods. A meta-analysis identified by searching the PubMed, Cochrane Library, EMBASE, and Web of Science databases from inception through December 2016 compared the effects of INTERVAL and CONTINUOUS among cardiac patients. Results. Twenty-one studies involving 736 participants with cardiac diseases were included. Compared with CONTINUOUS, INTERVAL was associated with greater improvement in peak VO2 (mean difference 1.76 mL/kg/min, 95% confidence interval 1.06 to 2.46 mL/kg/min, p < 0.001) and VO2 at AT (mean difference 0.90 mL/kg/min, 95% confidence interval 0.0 to 1.72 mL/kg/min, p = 0.03). No significant difference between the INTERVAL and CONTINUOUS groups was observed in terms of peak heart rate, peak minute ventilation, VE/VCO2 slope and respiratory exchange ratio, body mass, systolic or diastolic blood pressure, triglyceride or low- or high-density lipoprotein cholesterol level, flow-mediated dilation, or left ventricular ejection fraction. Conclusions. This study showed that INTERVAL improves aerobic capacity more effectively than does CONTINUOUS in cardiac patients. Further studies with larger samples are needed to confirm our observations. PMID:28386556

  1. Design of invisibility cloaks with an open tunnel.

    PubMed

    Ako, Thomas; Yan, Min; Qiu, Min

    2010-12-20

    In this paper we apply the methodology of transformation optics for design of a novel invisibility cloak which can possess an open tunnel. Such a cloak facilitates the insertion (retrieval) of matter into (from) the cloak's interior without significantly affecting the cloak's performance, overcoming the matter exchange bottleneck inherent to most previously proposed cloak designs.We achieve this by applying a transformation which expands a point at the origin in electromagnetic space to a finite area in physical space in a highly anisotropic manner. The invisibility performance of the proposed cloak is verified by using full-wave finite-element simulations.

  2. An adaptive semantic based mediation system for data interoperability among Health Information Systems.

    PubMed

    Khan, Wajahat Ali; Khattak, Asad Masood; Hussain, Maqbool; Amin, Muhammad Bilal; Afzal, Muhammad; Nugent, Christopher; Lee, Sungyoung

    2014-08-01

    Heterogeneity in the management of the complex medical data, obstructs the attainment of data level interoperability among Health Information Systems (HIS). This diversity is dependent on the compliance of HISs with different healthcare standards. Its solution demands a mediation system for the accurate interpretation of data in different heterogeneous formats for achieving data interoperability. We propose an adaptive AdapteR Interoperability ENgine mediation system called ARIEN, that arbitrates between HISs compliant to different healthcare standards for accurate and seamless information exchange to achieve data interoperability. ARIEN stores the semantic mapping information between different standards in the Mediation Bridge Ontology (MBO) using ontology matching techniques. These mappings are provided by our System for Parallel Heterogeneity (SPHeRe) matching system and Personalized-Detailed Clinical Model (P-DCM) approach to guarantee accuracy of mappings. The realization of the effectiveness of the mappings stored in the MBO is evaluation of the accuracy in transformation process among different standard formats. We evaluated our proposed system with the transformation process of medical records between Clinical Document Architecture (CDA) and Virtual Medical Record (vMR) standards. The transformation process achieved over 90 % of accuracy level in conversion process between CDA and vMR standards using pattern oriented approach from the MBO. The proposed mediation system improves the overall communication process between HISs. It provides an accurate and seamless medical information exchange to ensure data interoperability and timely healthcare services to patients.

  3. Gas exchange in the ice zone: the role of small waves and big animals

    NASA Astrophysics Data System (ADS)

    Loose, B.; Takahashi, A.; Bigdeli, A.

    2016-12-01

    The balance of air-sea gas exchange and net biological carbon fixation determine the transport and transformation of carbon dioxide and methane in the ocean. Air-sea gas exchange is mostly driven by upper ocean physics, but biology can also play a role. In the open ocean, gas exchange increases proportionate to the square of wind speed. When sea ice is present, this dependence breaks down in part because breaking waves and air bubble entrainment are damped out by interactions between sea ice and the wave field. At the same time, sea ice motions, formation, melt, and even sea ice-associated organisms can act to introduce turbulence and air bubbles into the upper ocean, thereby enhancing air-sea gas exchange. We take advantage of the knowledge advances of upper ocean physics including bubble dynamics to formulate a model for air-sea gas exchange in the sea ice zone. Here, we use the model to examine the role of small-scale waves and diving animals that trap air for insulation, including penguins, seals and polar bears. We compare these processes to existing parameterizations of wave and bubble dynamics in the open ocean, to observe how sea ice both mitigates and locally enhances air-sea gas transfer.

  4. The study of RMB exchange rate complex networks based on fluctuation mode

    NASA Astrophysics Data System (ADS)

    Yao, Can-Zhong; Lin, Ji-Nan; Zheng, Xu-Zhou; Liu, Xiao-Feng

    2015-10-01

    In the paper, we research on the characteristics of RMB exchange rate time series fluctuation with methods of symbolization and coarse gaining. First, based on fluctuation features of RMB exchange rate, we define the first type of fluctuation mode as one specific foreign currency against RMB in four days' fluctuating situations, and the second type as four different foreign currencies against RMB in one day's fluctuating situation. With the transforming method, we construct the unique-currency and multi-currency complex networks. Further, through analyzing the topological features including out-degree, betweenness centrality and clustering coefficient of fluctuation-mode complex networks, we find that the out-degree distribution of both types of fluctuation mode basically follows power-law distributions with exponents between 1 and 2. The further analysis reveals that the out-degree and the clustering coefficient generally obey the approximated negative correlation. With this result, we confirm previous observations showing that the RMB exchange rate exhibits a characteristic of long-range memory. Finally, we analyze the most probable transmission route of fluctuation modes, and provide probability prediction matrix. The transmission route for RMB exchange rate fluctuation modes exhibits the characteristics of partially closed loop, repeat and reversibility, which lays a solid foundation for predicting RMB exchange rate fluctuation patterns with large volume of data.

  5. A random effects meta-analysis model with Box-Cox transformation.

    PubMed

    Yamaguchi, Yusuke; Maruo, Kazushi; Partlett, Christopher; Riley, Richard D

    2017-07-19

    In a random effects meta-analysis model, true treatment effects for each study are routinely assumed to follow a normal distribution. However, normality is a restrictive assumption and the misspecification of the random effects distribution may result in a misleading estimate of overall mean for the treatment effect, an inappropriate quantification of heterogeneity across studies and a wrongly symmetric prediction interval. We focus on problems caused by an inappropriate normality assumption of the random effects distribution, and propose a novel random effects meta-analysis model where a Box-Cox transformation is applied to the observed treatment effect estimates. The proposed model aims to normalise an overall distribution of observed treatment effect estimates, which is sum of the within-study sampling distributions and the random effects distribution. When sampling distributions are approximately normal, non-normality in the overall distribution will be mainly due to the random effects distribution, especially when the between-study variation is large relative to the within-study variation. The Box-Cox transformation addresses this flexibly according to the observed departure from normality. We use a Bayesian approach for estimating parameters in the proposed model, and suggest summarising the meta-analysis results by an overall median, an interquartile range and a prediction interval. The model can be applied for any kind of variables once the treatment effect estimate is defined from the variable. A simulation study suggested that when the overall distribution of treatment effect estimates are skewed, the overall mean and conventional I 2 from the normal random effects model could be inappropriate summaries, and the proposed model helped reduce this issue. We illustrated the proposed model using two examples, which revealed some important differences on summary results, heterogeneity measures and prediction intervals from the normal random effects model. The random effects meta-analysis with the Box-Cox transformation may be an important tool for examining robustness of traditional meta-analysis results against skewness on the observed treatment effect estimates. Further critical evaluation of the method is needed.

  6. 77 FR 58600 - Self-Regulatory Organizations; BOX Options Exchange LLC; Notice of Filing and Immediate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ... approving expansion of STO Program)[sic]. \\9\\ These include, without limitation, options, equities, futures... hedging strategies across various investment platforms (e.g. equity and ETF, index, derivatives, futures... Web site, strike prices for options on futures may be at an interval of $.05, $.10, and $.25 per...

  7. Modeling Spatial and Temporal Variability of Residential Air Exchange Rates for the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS)

    EPA Science Inventory

    Air pollution health studies often use outdoor concentrations as exposure surrogates. Failure to account for variability of residential infiltration of outdoor pollutants can induce exposure errors and lead to bias and incorrect confidence intervals in health effect estimates. Th...

  8. 75 FR 6243 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-08

    ... capacity to handle the additional traffic associated with the listing and trading of $1 strikes (where the... Change, and Amendment No. 1 Thereto, To Establish Strike Price Intervals and Trading Hours for Options on... the commencement of trading options on Index-Linked Securities, CBOE proposes to establish strike...

  9. 76 FR 79748 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing of Proposed Rule Change...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-22

    ..., confirming that ``iShares[supreg]'' is a registered trademark of BlackRock Institutional Trust Company, N.A...''), NYSEArca (``Arca''), BATS Global Markets (``BATS''), Boston Options Exchange (``BOX''), Chicago Board... to the applicable ETF option interval standards of other options markets.\\6\\ \\6\\ See, for example...

  10. Use of argon to measure gas exchange in turbulent mountain streams

    NASA Astrophysics Data System (ADS)

    Hall, Robert O., Jr.; Madinger, Hilary L.

    2018-05-01

    Gas exchange is a parameter needed in stream metabolism and trace gas emissions models. One way to estimate gas exchange is via measuring the decline of added tracer gases such as sulfur hexafluoride (SF6). Estimates of oxygen (O2) gas exchange derived from SF6 additions require scaling via Schmidt number (Sc) ratio, but this scaling is uncertain under conditions of high gas exchange via bubbles because scaling depends on gas solubility as well as Sc. Because argon (Ar) and O2 have nearly identical Schmidt numbers and solubility, Ar may be a useful tracer gas for estimating stream O2 exchange. Here we compared rates of gas exchange measured via Ar and SF6 for turbulent mountain streams in Wyoming, USA. We measured Ar as the ratio of Ar : N2 using a membrane inlet mass spectrometer (MIMS). Normalizing to N2 confers higher precision than simply measuring [Ar] alone. We consistently enriched streams with Ar from 1 to 18 % of ambient Ar concentration and could estimate gas exchange rate using an exponential decline model. The mean ratio of gas exchange of Ar relative to SF6 was 1.8 (credible interval 1.1 to 2.5) compared to the theoretical estimate 1.35, showing that using SF6 would have underestimated exchange of Ar. Steep streams (slopes 11-12 %) had high rates of gas exchange velocity normalized to Sc = 600 (k600, 57-210 m d-1), and slope strongly predicted variation in k600 among all streams. We suggest that Ar is a useful tracer because it is easily measured, requires no scaling assumptions to estimate rates of O2 exchange, and is not an intense greenhouse gas as is SF6. We caution that scaling from rates of either Ar or SF6 gas exchange to CO2 is uncertain due to solubility effects in conditions of bubble-mediated gas transfer.

  11. Comparative ex vivo study on humidifying function of three speaking valves with integrated heat and moisture exchanger for tracheotomised patients.

    PubMed

    van den Boer, C; Lansaat, L; Muller, S H; van den Brekel, M W M; Hilgers, F J M

    2015-12-01

    Assessment of humidifying function of tracheotomy speaking valves with integrated heat and moisture exchanger. Ex vivo measurement of water exchange and storage capacity of three tracheotomy speaking valves: Humidiphon Plus, Spiro and ProTrach DualCare (with two different heat and moisture exchangers: XtraMoist and Regular). Comprehensive Cancer Centre. Healthy volunteer. Difference between end-inspiratory and end-expiratory weight as measure for water exchange capacity, weight after 10 min breathing as measure for water storage capacity, weighing at 1-min intervals to assess residual water exchange potential in speaking mode and absolute humidity in mg/L as measure for environmental and respiratory humidity. None of the tracheotomy speaking valves provides humidification while in speaking mode. Only the ProTrach DualCare allows blocking the speaking valve and breathing through the heat and moisture exchanger during inhalation and exhalation (heat and moisture exchanger mode). This leads to an increase in inspiratory humidity of 2.5 mg (XtraMoist) and 1.6 mg (Regular). There was no measurable water storage in speaking mode in any of the three tracheotomy speaking valves. In breathing mode, water storage in the DualCare heat and moisture exchangers was 47 and 37 mg, respectively. The remaining humidifying potential in speaking mode after 10 min breathing in heat and moisture exchanger mode for XtraMoist was 38%, 15% and 10% at 1, 2 and 3 min, respectively. For Regular, this was 47%, 24% and 13%, respectively. Tracheostoma valves with integrated heat and moisture exchanger have no humidification function in speaking mode. Only ProTrach DualCare, allowing blocking the speaking mode, in heat and moisture exchanger mode enables a significant increase in humidification. Regular switching between speaking and heat and moisture exchanger mode with this latter device prolongs the humidification in speaking mode. © 2015 John Wiley & Sons Ltd.

  12. A computational algorithm for spacecraft control and momentum management

    NASA Technical Reports Server (NTRS)

    Dzielski, John; Bergmann, Edward; Paradiso, Joseph

    1990-01-01

    Developments in the area of nonlinear control theory have shown how coordinate changes in the state and input spaces of a dynamical system can be used to transform certain nonlinear differential equations into equivalent linear equations. These techniques are applied to the control of a spacecraft equipped with momentum exchange devices. An optimal control problem is formulated that incorporates a nonlinear spacecraft model. An algorithm is developed for solving the optimization problem using feedback linearization to transform to an equivalent problem involving a linear dynamical constraint and a functional approximation technique to solve for the linear dynamics in terms of the control. The original problem is transformed into an unconstrained nonlinear quadratic program that yields an approximate solution to the original problem. Two examples are presented to illustrate the results.

  13. Does cemented or cementless single-stage exchange arthroplasty of chronic periprosthetic hip infections provide similar infection rates to a two-stage? A systematic review.

    PubMed

    George, D A; Logoluso, N; Castellini, G; Gianola, S; Scarponi, S; Haddad, F S; Drago, L; Romano, C L

    2016-10-10

    The best surgical modality for treating chronic periprosthetic hip infections remains controversial, with a lack of randomised controlled studies. The aim of this systematic review is to compare the infection recurrence rate after a single-stage versus a two-stage exchange arthroplasty, and the rate of cemented versus cementless single-stage exchange arthroplasty for chronic periprosthetic hip infections. We searched for eligible studies published up to December 2015. Full text or abstract in English were reviewed. We included studies reporting the infection recurrence rate as the outcome of interest following single- or two-stage exchange arthroplasty, or both, with a minimum follow-up of 12 months. Two reviewers independently abstracted data and appraised quality assessment. After study selection, 90 observational studies were included. The majority of studies were focused on a two-stage hip exchange arthroplasty (65 %), 18 % on a single-stage exchange, and only a 17 % were comparative studies. There was no statistically significant difference between a single-stage versus a two-stage exchange in terms of recurrence of infection in controlled studies (pooled odds ratio of 1.37 [95 % CI = 0.68-2.74, I 2  = 45.5 %]). Similarly, the recurrence infection rate in cementless versus cemented single-stage hip exchanges failed to demonstrate a significant difference, due to the substantial heterogeneity among the studies. Despite the methodological limitations and the heterogeneity between single cohorts studies, if we considered only the available controlled studies no superiority was demonstrated between a single- and two-stage exchange at a minimum of 12 months follow-up. The overalapping of confidence intervals related to single-stage cementless and cemented hip exchanges, showed no superiority of either technique.

  14. Survivorship of Total Hip Joint Replacements Following Isolated Liner Exchange for Wear.

    PubMed

    Vadei, Leone; Kieser, David C; Frampton, Chris; Hooper, Gary

    2017-11-01

    Liner exchange for articular component wear in total hip joint replacements (THJRs) is a common procedure, often thought to be benign with reliable outcomes. Recent studies, however, suggest high failure rates of liner exchange revisions with significant complications. The primary aim of this study was, therefore, to analyze the survivorship of isolated liner exchange for articular component wear, and secondarily to assess the influence of patient demographics (gender, age, and American Society of Anaesthesiologists [ASA] ratings) on rerevisions following isolated liner exchange for wear. A retrospective review of the 15-year New Zealand Joint Registry (1999-2014) was performed, analyzing the outcomes of isolated liner exchange for articular component wear. The survivorship as defined as rerevision with component exchange was determined and 10-year Kaplan-Meier survivorship curves were constructed. These revision rates were compared to age, gender, and ASA rating groups using a log-rank test. The 10-year survivorship of THJR following liner exchange revision for liner wear was 75.3%. If a rerevision was required, the median time to rerevision was 1.33 years with a rerevision rate of 3.33 per 100 component years (95% confidence interval 2.68-4.08/100 component years). The principle reasons for rerevision were dislocation (48.4%) and acetabular component loosening (20.9%). There was no statistically significant difference in rerevision rates based on gender, age categories, or ASA scores. THJR isolated liner exchange for liner wear is not a benign procedure with a survivorship of 75.3% at 10 years. Surgeons contemplating liner exchange revisions should be cognisant of this risk and should adequately assess component position and stability preoperatively. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Method for determining formation quality factor from seismic data

    DOEpatents

    Taner, M. Turhan; Treitel, Sven

    2005-08-16

    A method is disclosed for calculating the quality factor Q from a seismic data trace. The method includes calculating a first and a second minimum phase inverse wavelet at a first and a second time interval along the seismic data trace, synthetically dividing the first wavelet by the second wavelet, Fourier transforming the result of the synthetic division, calculating the logarithm of this quotient of Fourier transforms and determining the slope of a best fit line to the logarithm of the quotient.

  16. The Great American Biotic Interchange: Dispersals, Tectonics, Climate, Sea Level and Holding Pens

    PubMed Central

    2010-01-01

    The biotic and geologic dynamics of the Great American Biotic Interchange are reviewed and revised. Information on the Marine Isotope Stage chronology, sea level changes as well as Pliocene and Pleistocene vegetation changes in Central and northern South America add to a discussion of the role of climate in facilitating trans-isthmian exchanges. Trans-isthmian land mammal exchanges during the Pleistocene glacial intervals appear to have been promoted by the development of diverse non-tropical ecologies. Electronic supplementary material The online version of this article (doi:10.1007/s10914-010-9144-8) contains supplementary material, which is available to authorized users. PMID:21125025

  17. Optimal temperature ladders in replica exchange simulations

    NASA Astrophysics Data System (ADS)

    Denschlag, Robert; Lingenheil, Martin; Tavan, Paul

    2009-04-01

    In replica exchange simulations, a temperature ladder with N rungs spans a given temperature interval. Considering systems with heat capacities independent of the temperature, here we address the question of how large N should be chosen for an optimally fast diffusion of the replicas through the temperature space. Using a simple example we show that choosing average acceptance probabilities of about 45% and computing N accordingly maximizes the round trip rates r across the given temperature range. This result differs from previous analyses which suggested smaller average acceptance probabilities of about 23%. We show that the latter choice maximizes the ratio r/N instead of r.

  18. Transformative Travel--Experiences in Mexico, NYC Change Students' Lives

    ERIC Educational Resources Information Center

    Sorensen, Barbara Ellen

    2010-01-01

    Traveling outside one's comfort zone can plant the seeds for a collaborative, positive exchange of ideas, information, and perspectives. And that's just what happened when two groups of tribal college students, representing many nations, embraced traveling far from their families and communities. These two groups of students and faculty--one from…

  19. Communication Competence and Trust in Leaders: From Transactional, through Transitional, to Transformational Exchanges

    ERIC Educational Resources Information Center

    Sutherland, Ian Edwin

    2011-01-01

    Trust is recognized as a critical component of effective leadership. However, limited empirical evidence exists that provides support for specific leader behaviors that contribute to the development of trust in followers. One way trust forms is through the experiences in the history of communication transactions between individuals. The Spitzberg…

  20. Undoing the Knots: Identity Transformations in a Study Abroad Programme

    ERIC Educational Resources Information Center

    Ellwood, Constance

    2011-01-01

    In times of globalised flows of students, this paper offers an alternative way of conceptualising identity change in the experiences of students on study abroad or student exchange programmes. Despite the "identity turn" of recent years, modernist notions of identity continue to impact on the ways in which study abroad experiences are…

  1. Pizza: Teaching US History through Food and Place

    ERIC Educational Resources Information Center

    Marino, Michael P.; Crocco, Margaret S.

    2015-01-01

    Pizza serves as a powerful example of historical themes such as immigration, cultural exchange and urbanization. In the post-WWII United States, Trenton, NJ, and other cities were gradually being transformed by suburbanization, the rise of fast food, and changes in family living related to women's entry in large numbers into the paid workforce.…

  2. Leadership, Innovation Climate, and Attitudes toward Evidence-Based Practice during a Statewide Implementation

    ERIC Educational Resources Information Center

    Aarons, Gregory A.; Sommerfeld, David H.

    2012-01-01

    Objective: Leadership is important in practice change, yet there are few studies addressing this issue in mental health and social services. This study examined the differential roles of transformational (i.e., charismatic) leadership and leader-member exchange (i.e., the relationship between a supervisor and their direct service providers) on…

  3. Facing Future Users--The Challenge of Transforming a Traditional Online Database into a Web Service.

    ERIC Educational Resources Information Center

    Tolonen, Eva

    The Energy Technology Data Exchange (ETDE) agreement included 19 member countries spanning four continents: Japan and the Republic of Korea; Belgium, Denmark, Finland, France, Germany, Italy, The Netherlands, Norway, Poland, Spain, Sweden, Switzerland, and the United Kingdom; Canada, Mexico, and the United States; and Brazil. The participating…

  4. The Voyages of Columbus: A Turning Point in World History.

    ERIC Educational Resources Information Center

    Crosby, Alfred W.; Nader, Helen

    The far-reaching and transforming interactions of the Old World and the New are known today as "the Columbian Exchange." Part 1 of this booklet is an introduction by John J. Patrick dealing with teaching about the voyages of Christopher Columbus. Part 2, "Columbus and Ecological Imperialism," by Alfred W. Crosby, provides an…

  5. 21 CFR 500.45 - Use of polychlorinated biphenyls (PCB's) in the production, handling, and storage of animal feed.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... highly stable, heat resistant, and nonflammable chemicals. Industrial uses of PCB's include, or did include in the past, their use as electrical transformer and capacitor fluids, heat transfer fluids... Food and Drug Administration have revealed that heat exchange fluids for certain pasteurization...

  6. Gifts of the Magi: "Chef," "Million Dollar Arm," and Cultural Mixtures

    ERIC Educational Resources Information Center

    Beck, Bernard

    2014-01-01

    When groups using different cultural systems encounter one another in diverse societies, their previous cultures are transformed into a merged, complex cultural picture. Some culture areas are preserved while others are adjusted, exchanged, and merged. In our society, introducing groups to the cooking of other groups is a form of contact which…

  7. Making an Author's Visit Your Best "Good Time"

    ERIC Educational Resources Information Center

    Follos, Alison

    2004-01-01

    Stories speak to people in different ways. Yet it is the person behind the story who pushes the literature into a malleable body of imaginative possibilities. Author visits transform quiet written words from a private exchange between reader and author into a lively community discussion. North Country School, in northern New York, sits in the…

  8. Standard biological parts knowledgebase.

    PubMed

    Galdzicki, Michal; Rodriguez, Cesar; Chandran, Deepak; Sauro, Herbert M; Gennari, John H

    2011-02-24

    We have created the Knowledgebase of Standard Biological Parts (SBPkb) as a publically accessible Semantic Web resource for synthetic biology (sbolstandard.org). The SBPkb allows researchers to query and retrieve standard biological parts for research and use in synthetic biology. Its initial version includes all of the information about parts stored in the Registry of Standard Biological Parts (partsregistry.org). SBPkb transforms this information so that it is computable, using our semantic framework for synthetic biology parts. This framework, known as SBOL-semantic, was built as part of the Synthetic Biology Open Language (SBOL), a project of the Synthetic Biology Data Exchange Group. SBOL-semantic represents commonly used synthetic biology entities, and its purpose is to improve the distribution and exchange of descriptions of biological parts. In this paper, we describe the data, our methods for transformation to SBPkb, and finally, we demonstrate the value of our knowledgebase with a set of sample queries. We use RDF technology and SPARQL queries to retrieve candidate "promoter" parts that are known to be both negatively and positively regulated. This method provides new web based data access to perform searches for parts that are not currently possible.

  9. Ligand Exchange Kinetics of Environmentally Relevant Metals

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Panasci, Adele Frances

    2014-07-15

    The interactions of ground water with minerals and contaminants are of broad interest for geochemists but are not well understood. Experiments on the molecular scale can determine reaction parameters (i.e. rates of ligand exchange, activation entropy, activation entropy, and activation volume) that can be used in computations to gain insight into reactions that occur in natural groundwaters. Experiments to determine the rate of isotopic ligand exchange for three environmentally relevant metals, rhodium (Rh), iron (Fe), and neptunium (Np), are described. Many environmental transformations of metals (e.g. reduction) in soil occur at trivalent centers, Fe(III) in particular. Contaminant ions absorb tomore » mineral surfaces via ligand exchange, and the reversal of this reaction can be dangerous, releasing contaminants into the environment. Ferric iron is difficult to study spectroscopically because most of its complexes are paramagnetic and are generally reactive toward ligand exchange; therefore, Rh(III), which is diamagnetic and less reactive, was used to study substitution reactions that are analogous to those that occur on mineral oxide surfaces. Studies on both Np(V) and Np(VI) are important in their own right, as 237Np is a radioactive transuranic element with a half-life of 2 million years.« less

  10. Improved treatment of exact exchange in Quantum ESPRESSO

    DOE PAGES

    Barnes, Taylor A.; Kurth, Thorsten; Carrier, Pierre; ...

    2017-01-18

    Here, we present an algorithm and implementation for the parallel computation of exact exchange in Quantum ESPRESSO (QE) that exhibits greatly improved strong scaling. QE is an open-source software package for electronic structure calculations using plane wave density functional theory, and supports the use of local, semi-local, and hybrid DFT functionals. Wider application of hybrid functionals is desirable for the improved simulation of electronic band energy alignments and thermodynamic properties, but the computational complexity of evaluating the exact exchange potential limits the practical application of hybrid functionals to large systems and requires efficient implementations. We demonstrate that existing implementations ofmore » hybrid DFT that utilize a single data structure for both the local and exact exchange regions of the code are significantly limited in the degree of parallelization achievable. We present a band-pair parallelization approach, in which the calculation of exact exchange is parallelized and evaluated independently from the parallelization of the remainder of the calculation, with the wavefunction data being efficiently transformed on-the-fly into a form that is optimal for each part of the calculation. For a 64 water molecule supercell, our new algorithm reduces the overall time to solution by nearly an order of magnitude.« less

  11. 3D numerical modeling of hyporheic exchange processes in fractal riverbed

    NASA Astrophysics Data System (ADS)

    Lee, A.; Aubeneau, A.

    2017-12-01

    The subsurface region receiving stream water is known as the hyporheic zone and the flow of water in and out of this zone is called hyporheic exchange. The hyporheic zone is populated by biofilms and is a hotspot for nutrient uptake and contaminant transformation. Traditionally, pumping models predicting the head distribution over the riverbed boundary are used to obtain the velocity field in the subsurface. However, past research has largely overlooked the nonlinearity of the turbulent flow above the bumpy riverbed. The main objective of this research is to investigate the effect of spatial and temporal heterogeneity created by turbulent flow on hyporheic exchange and residence time distribution in fractal channel beds. The 3-D fractal riverbed is created from the power spectrum. Large-Eddy Simulation is used to provide the pressure field over the benthic boundary. Finally, Darcian fluxes in the sub-surface are calculated and hyporheic travel times computed using random walks. Surface and subsurface transport processes are represented explicitly and can be studied in detail. Our results suggest that (1) Eddies and wakes around the dunes force the exchange (2) The bigger the dunes, the greater the influence of turbulence (3) Turbulence induces more exchange than pumping predicts.

  12. Final cooling for a high-energy high-luminosity lepton collider

    NASA Astrophysics Data System (ADS)

    Neuffer, D.; Sayed, H.; Acosta, J.; Hart, T.; Summers, D.

    2017-07-01

    A high-energy muon collider requires a "final cooling" system that reduces transverse emittance by a factor of ~ 10, while allowing the longitudinal emittance to increase. The baseline approach has low-energy transverse cooling within high-field solenoids, with strong longitudinal heating. This approach and its recent simulation are discussed. Alternative approaches, which more explicitly include emittance exchange are also presented. Round-to-flat beam transform, transverse slicing, and longitudinal bunch coalescence are possible components of an alternative approach. Wedge-based emittance exchange could provide much of the required transverse cooling with longitudinal heating. Li-lens and quadrupole focusing systems could also provide much of the required final cooling.

  13. Simulation data for an estimation of the maximum theoretical value and confidence interval for the correlation coefficient.

    PubMed

    Rocco, Paolo; Cilurzo, Francesco; Minghetti, Paola; Vistoli, Giulio; Pedretti, Alessandro

    2017-10-01

    The data presented in this article are related to the article titled "Molecular Dynamics as a tool for in silico screening of skin permeability" (Rocco et al., 2017) [1]. Knowledge of the confidence interval and maximum theoretical value of the correlation coefficient r can prove useful to estimate the reliability of developed predictive models, in particular when there is great variability in compiled experimental datasets. In this Data in Brief article, data from purposely designed numerical simulations are presented to show how much the maximum r value is worsened by increasing the data uncertainty. The corresponding confidence interval of r is determined by using the Fisher r → Z transform.

  14. Mixing effects on nitrogen and oxygen concentrations and the relationship to mean residence time in a hyporheic zone of a riffle-pool sequence

    USGS Publications Warehouse

    Naranjo, Ramon C.; Niswonger, Richard G.; Clinton Davis,

    2015-01-01

    Flow paths and residence times in the hyporheic zone are known to influence biogeochemical processes such as nitrification and denitrification. The exchange across the sediment-water interface may involve mixing of surface water and groundwater through complex hyporheic flow paths that contribute to highly variable biogeochemically active zones. Despite the recognition of these patterns in the literature, conceptualization and analysis of flow paths and nitrogen transformations beneath riffle-pool sequences often neglect to consider bed form driven exchange along the entire reach. In this study, the spatial and temporal distribution of dissolved oxygen (DO), nitrate (NO3-) and ammonium (NH4+) were monitored in the hyporheic zone beneath a riffle-pool sequence on a losing section of the Truckee River, NV. Spatially-varying hyporheic exchange and the occurrence of multi-scale hyporheic mixing cells are shown to influence concentrations of DO and NO3- and the mean residence time (MRT) of riffle and pool areas. Distinct patterns observed in piezometers are shown to be influenced by the first large flow event following a steady 8 month period of low flow conditions. Increases in surface water discharge resulted in reversed hydraulic gradients and production of nitrate through nitrification at small vertical spatial scales (0.10 to 0.25 m) beneath the sediment-water interface. In areas with high downward flow rates and low MRT, denitrification may be limited. The use of a longitudinal two-dimensional flow model helped identify important mechanisms such as multi-scale hyporheic mixing cells and spatially varying MRT, an important driver for nitrogen transformation in the riverbed. Our observations of DO and NO3- concentrations and model simulations highlight the role of multi-scale hyporheic mixing cells on MRT and nitrogen transformations in the hyporheic zone of riffle-pool sequences. This article is protected by copyright. All rights reserved.

  15. Layered zinc hydroxide nanocones: synthesis, facile morphological and structural modification, and properties

    NASA Astrophysics Data System (ADS)

    Ma, Wei; Ma, Renzhi; Liang, Jianbo; Wang, Chengxiang; Liu, Xiaohe; Zhou, Kechao; Sasaki, Takayoshi

    2014-10-01

    Layered zinc hydroxide nanocones intercalated with DS- have been synthesized for the first time via a convenient synthetic approach, using homogeneous precipitation in the presence of urea and sodium dodecyl sulfate (SDS). SDS plays a significant role in controlling the morphologies of as-synthesized samples. Conical samples intercalated with various anions were transformed through an anion-exchange route in ethanol solution, and the original conical structure was perfectly maintained. Additionally, these DS--inserted nanocones can be transformed into square-like nanoplates in aqueous solution at room temperature, fulfilling the need for different morphology-dependent properties. Corresponding ZnO nanocones and nanoplates have been further obtained through the thermal calcination of NO3--intercalating zinc hydroxide nanocones/nanoplates. These ZnO nanostructures with different morphologies exhibit promising photocatalytic properties.Layered zinc hydroxide nanocones intercalated with DS- have been synthesized for the first time via a convenient synthetic approach, using homogeneous precipitation in the presence of urea and sodium dodecyl sulfate (SDS). SDS plays a significant role in controlling the morphologies of as-synthesized samples. Conical samples intercalated with various anions were transformed through an anion-exchange route in ethanol solution, and the original conical structure was perfectly maintained. Additionally, these DS--inserted nanocones can be transformed into square-like nanoplates in aqueous solution at room temperature, fulfilling the need for different morphology-dependent properties. Corresponding ZnO nanocones and nanoplates have been further obtained through the thermal calcination of NO3--intercalating zinc hydroxide nanocones/nanoplates. These ZnO nanostructures with different morphologies exhibit promising photocatalytic properties. Electronic supplementary information (ESI) available: Typical SEM images, TGA curves and XRD patterns of as-prepared samples. See DOI: 10.1039/c4nr04166f

  16. Embryo-specific expression of a visual reporter gene as a selection system for citrus transformation

    PubMed Central

    Zambon, Flavia T.; Erpen, Lígia; Soriano, Leonardo; Grosser, Jude

    2018-01-01

    The embryo-specific Dc3 gene promoter driving the VvMybA1 anthocyanin regulatory gene was used to develop a visual selection system for the genetic transformation of citrus. Agrobacterium-mediated transformation of cell suspension cultures resulted in the production of purple transgenic somatic embryos that could be easily separated from the green non-transgenic embryos. The somatic embryos produced phenotypically normal plants devoid of any visual purple coloration. These results were also confirmed using protoplast transformation. There was minimal gene expression in unstressed one-year-old transgenic lines. Cold and drought stress did not have any effect on gene expression, while exogenous ABA and NaCl application resulted in a minor change in gene expression in several transgenic lines. When gas exchange was measured in intact leaves, the transgenic lines were similar to controls under the same environment. Our results provide conclusive evidence for the utilization of a plant-derived, embryo-specific visual reporter system for the genetic transformation of citrus. Such a system could aid in the development of an all-plant, consumer-friendly GM citrus tree. PMID:29293649

  17. State transformations and Hamiltonian structures for optimal control in discrete systems

    NASA Astrophysics Data System (ADS)

    Sieniutycz, S.

    2006-04-01

    Preserving usual definition of Hamiltonian H as the scalar product of rates and generalized momenta we investigate two basic classes of discrete optimal control processes governed by the difference rather than differential equations for the state transformation. The first class, linear in the time interval θ, secures the constancy of optimal H and satisfies a discrete Hamilton-Jacobi equation. The second class, nonlinear in θ, does not assure the constancy of optimal H and satisfies only a relationship that may be regarded as an equation of Hamilton-Jacobi type. The basic question asked is if and when Hamilton's canonical structures emerge in optimal discrete systems. For a constrained discrete control, general optimization algorithms are derived that constitute powerful theoretical and computational tools when evaluating extremum properties of constrained physical systems. The mathematical basis is Bellman's method of dynamic programming (DP) and its extension in the form of the so-called Carathéodory-Boltyanski (CB) stage optimality criterion which allows a variation of the terminal state that is otherwise fixed in Bellman's method. For systems with unconstrained intervals of the holdup time θ two powerful optimization algorithms are obtained: an unconventional discrete algorithm with a constant H and its counterpart for models nonlinear in θ. We also present the time-interval-constrained extension of the second algorithm. The results are general; namely, one arrives at: discrete canonical equations of Hamilton, maximum principles, and (at the continuous limit of processes with free intervals of time) the classical Hamilton-Jacobi theory, along with basic results of variational calculus. A vast spectrum of applications and an example are briefly discussed with particular attention paid to models nonlinear in the time interval θ.

  18. Predicting birth weight with conditionally linear transformation models.

    PubMed

    Möst, Lisa; Schmid, Matthias; Faschingbauer, Florian; Hothorn, Torsten

    2016-12-01

    Low and high birth weight (BW) are important risk factors for neonatal morbidity and mortality. Gynecologists must therefore accurately predict BW before delivery. Most prediction formulas for BW are based on prenatal ultrasound measurements carried out within one week prior to birth. Although successfully used in clinical practice, these formulas focus on point predictions of BW but do not systematically quantify uncertainty of the predictions, i.e. they result in estimates of the conditional mean of BW but do not deliver prediction intervals. To overcome this problem, we introduce conditionally linear transformation models (CLTMs) to predict BW. Instead of focusing only on the conditional mean, CLTMs model the whole conditional distribution function of BW given prenatal ultrasound parameters. Consequently, the CLTM approach delivers both point predictions of BW and fetus-specific prediction intervals. Prediction intervals constitute an easy-to-interpret measure of prediction accuracy and allow identification of fetuses subject to high prediction uncertainty. Using a data set of 8712 deliveries at the Perinatal Centre at the University Clinic Erlangen (Germany), we analyzed variants of CLTMs and compared them to standard linear regression estimation techniques used in the past and to quantile regression approaches. The best-performing CLTM variant was competitive with quantile regression and linear regression approaches in terms of conditional coverage and average length of the prediction intervals. We propose that CLTMs be used because they are able to account for possible heteroscedasticity, kurtosis, and skewness of the distribution of BWs. © The Author(s) 2014.

  19. Acid transformation of bauxite residue: Conversion of its alkaline characteristics.

    PubMed

    Kong, Xiangfeng; Li, Meng; Xue, Shengguo; Hartley, William; Chen, Chengrong; Wu, Chuan; Li, Xiaofei; Li, Yiwei

    2017-02-15

    Bauxite residue (BR) is a highly alkaline solid hazardous waste produced from bauxite processing for alumina production. Alkaline transformation appears to reduce the environmental risk of bauxite residue disposal areas (BRDAs) whilst potentially providing opportunities for the sustainable reuse and on-going management of BR. Mineral acids, a novel citric acid and a hybrid combination of acid-gypsum treatments were investigated for their potential to reduce residue pH and total alkalinity and transform the alkaline mineral phase. XRD results revealed that with the exception of andradite, the primary alkaline solid phases of cancrinite, grossular and calcite were transformed into discriminative products based on the transformation used. Supernatants separated from BR and transformed bauxite residue (TBR) displayed distinct changes in soluble Na, Ca and Al, and a reduction in pH and total alkalinity. SEM images suggest that mineral acid transformations promote macro-aggregate formation, and the positive promotion of citric acid, confirming the removal or reduction in soluble and exchangeable Na. NEXAFS analysis of Na K-edge revealed that the chemical speciation of Na in TBRs was consistent with BR. Three acid treatments and gypsum combination had no effect on Na speciation, which affects the distribution of Na revealed by sodium STXM imaging. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Rock classification based on resistivity patterns in electrical borehole wall images

    NASA Astrophysics Data System (ADS)

    Linek, Margarete; Jungmann, Matthias; Berlage, Thomas; Pechnig, Renate; Clauser, Christoph

    2007-06-01

    Electrical borehole wall images represent grey-level-coded micro-resistivity measurements at the borehole wall. Different scientific methods have been implemented to transform image data into quantitative log curves. We introduce a pattern recognition technique applying texture analysis, which uses second-order statistics based on studying the occurrence of pixel pairs. We calculate so-called Haralick texture features such as contrast, energy, entropy and homogeneity. The supervised classification method is used for assigning characteristic texture features to different rock classes and assessing the discriminative power of these image features. We use classifiers obtained from training intervals to characterize the entire image data set recovered in ODP hole 1203A. This yields a synthetic lithology profile based on computed texture data. We show that Haralick features accurately classify 89.9% of the training intervals. We obtained misclassification for vesicular basaltic rocks. Hence, further image analysis tools are used to improve the classification reliability. We decompose the 2D image signal by the application of wavelet transformation in order to enhance image objects horizontally, diagonally and vertically. The resulting filtered images are used for further texture analysis. This combined classification based on Haralick features and wavelet transformation improved our classification up to a level of 98%. The application of wavelet transformation increases the consistency between standard logging profiles and texture-derived lithology. Texture analysis of borehole wall images offers the potential to facilitate objective analysis of multiple boreholes with the same lithology.

  1. Effect of pulsed laser irradiation on the structural and the magnetic properties of NiMn/Co exchange bias system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mohanan, Senthilnathan; Diebolder, Rolf; Hibst, Raimund

    2008-04-01

    We report about the influence of pulsed laser irradiation on the structural and magnetic properties of NiMn/Co thin films. Rocking curve measurements showed a significant improvement of the (111) texture of NiMn after laser irradiation which was accompanied by grain growth. We have studied the ordering transition in as-prepared and irradiated (laser fluence of 0.15 J/cm{sup 2}) samples during subsequent annealing. The onset of the fcc to fct phase transformation occurs at 325 deg. C irrespective of laser irradiation. Exchange bias fields for the laser irradiated samples are higher than those of the as-prepared samples. The observed increase in themore » exchange bias field for laser irradiated samples has been attributed to the increased grain size and the improved (111) texture of the NiMn layer after laser irradiation.« less

  2. Violation of the continuity equation in the Krieger-Li-Iafrate approximation for current-density functional theory

    NASA Astrophysics Data System (ADS)

    Siegmund, Marc; Pankratov, Oleg

    2011-01-01

    We show that the exchange-correlation scalar and vector potentials obtained from the optimized effective potential (OEP) equations and from the Krieger-Li-Iafrate (KLI) approximation for the current-density functional theory (CDFT) change under a gauge transformation such that the energy functional remains invariant. This alone does not assure, however, the theory’s compliance with the continuity equation. Using the model of a quantum ring with a broken angular symmetry which is penetrated by a magnetic flux we demonstrate that the physical current density calculated with the exact-exchange CDFT in the KLI approximation violates the continuity condition. In contrast, the current found from a solution of the full OEP equations satisfies this condition. We argue that the continuity violation stems from the fact that the KLI potentials are not (in general) the exact functional derivatives of a gauge-invariant exchange-correlation functional.

  3. Finite state model and compatibility theory - New analysis tools for permutation networks

    NASA Technical Reports Server (NTRS)

    Huang, S.-T.; Tripathi, S. K.

    1986-01-01

    A simple model to describe the fundamental operation theory of shuffle-exchange-type permutation networks, the finite permutation machine (FPM), is described, and theorems which transform the control matrix result to a continuous compatible vector result are developed. It is found that only 2n-1 shuffle exchange passes are necessary, and that 3n-3 passes are sufficient, to realize all permutations, reducing the sufficient number of passes by two from previous results. The flexibility of the approach is demonstrated by the description of a stack permutation machine (SPM) which can realize all permutations, and by showing that the FPM corresponding to the Benes (1965) network belongs to the SPM. The FPM corresponding to the network with two cascaded reverse-exchange networks is found to realize all permutations, and a simple mechanism to verify several equivalence relationships of various permutation networks is discussed.

  4. Design and Implementation of Geothermal Energy Systems at West Chester University

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lewis, James

    West Chester University has launched a comprehensive transformation of its campus heating and cooling systems from traditional fossil fuels to geothermal. This change will significantly decrease the institution's carbon footprint and serve as a national model for green campus efforts. The institution has designed a phased series of projects to build a district geo-exchange system with shared well fields, central pumping station and distribution piping to provide the geo-exchange water to campus buildings as their internal building HVAC systems are changed to be able to use the geo-exchange water. This project addresses the US Department of Energy Office of Energymore » Efficiency and Renewable Energy (EERE) goal to invest in clean energy technologies that strengthen the economy, protect the environment, and reduce dependence on foreign oil. In addition, this project advances EERE's efforts to establish geothermal energy as an economically competitive contributor to the US energy supply.« less

  5. Detection of statistical asymmetries in non-stationary sign time series: Analysis of foreign exchange data

    PubMed Central

    Takayasu, Hideki; Takayasu, Misako

    2017-01-01

    We extend the concept of statistical symmetry as the invariance of a probability distribution under transformation to analyze binary sign time series data of price difference from the foreign exchange market. We model segments of the sign time series as Markov sequences and apply a local hypothesis test to evaluate the symmetries of independence and time reversion in different periods of the market. For the test, we derive the probability of a binary Markov process to generate a given set of number of symbol pairs. Using such analysis, we could not only segment the time series according the different behaviors but also characterize the segments in terms of statistical symmetries. As a particular result, we find that the foreign exchange market is essentially time reversible but this symmetry is broken when there is a strong external influence. PMID:28542208

  6. Synthesis, characterisation and anion exchange properties of copper, magnesium, zinc and nickel hydroxy nitrates

    NASA Astrophysics Data System (ADS)

    Biswick, Timothy; Jones, William; Pacuła, Aleksandra; Serwicka, Ewa

    2006-01-01

    Anion exchange reactions of four structurally related hydroxy salts, Cu 2(OH) 3NO 3, Mg 2(OH) 3NO 3, Ni 2(OH) 3NO 3 and Zn 3(OH) 4(NO 3) 2 are compared and trends rationalised in terms of the strength of the covalent bond between the nitrate group and the matrix cation. Powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and elemental analysis are used to characterise the materials. Replacement of the nitrate anions in the zinc and copper salts with benzoate anions is possible although exchange of the zinc salt is accompanied by modification of the layer structure from one where zinc is exclusively six-fold coordinated to a structure where there is both six- and four-fold zinc coordination. Magnesium and nickel hydroxy nitrates, on the other hand, hydrolyse to their respective metal hydroxides.

  7. A modified Wald interval for the area under the ROC curve (AUC) in diagnostic case-control studies

    PubMed Central

    2014-01-01

    Background The area under the receiver operating characteristic (ROC) curve, referred to as the AUC, is an appropriate measure for describing the overall accuracy of a diagnostic test or a biomarker in early phase trials without having to choose a threshold. There are many approaches for estimating the confidence interval for the AUC. However, all are relatively complicated to implement. Furthermore, many approaches perform poorly for large AUC values or small sample sizes. Methods The AUC is actually a probability. So we propose a modified Wald interval for a single proportion, which can be calculated on a pocket calculator. We performed a simulation study to compare this modified Wald interval (without and with continuity correction) with other intervals regarding coverage probability and statistical power. Results The main result is that the proposed modified Wald intervals maintain and exploit the type I error much better than the intervals of Agresti-Coull, Wilson, and Clopper-Pearson. The interval suggested by Bamber, the Mann-Whitney interval without transformation and also the interval of the binormal AUC are very liberal. For small sample sizes the Wald interval with continuity has a comparable coverage probability as the LT interval and higher power. For large sample sizes the results of the LT interval and of the Wald interval without continuity correction are comparable. Conclusions If individual patient data is not available, but only the estimated AUC and the total sample size, the modified Wald intervals can be recommended as confidence intervals for the AUC. For small sample sizes the continuity correction should be used. PMID:24552686

  8. A modified Wald interval for the area under the ROC curve (AUC) in diagnostic case-control studies.

    PubMed

    Kottas, Martina; Kuss, Oliver; Zapf, Antonia

    2014-02-19

    The area under the receiver operating characteristic (ROC) curve, referred to as the AUC, is an appropriate measure for describing the overall accuracy of a diagnostic test or a biomarker in early phase trials without having to choose a threshold. There are many approaches for estimating the confidence interval for the AUC. However, all are relatively complicated to implement. Furthermore, many approaches perform poorly for large AUC values or small sample sizes. The AUC is actually a probability. So we propose a modified Wald interval for a single proportion, which can be calculated on a pocket calculator. We performed a simulation study to compare this modified Wald interval (without and with continuity correction) with other intervals regarding coverage probability and statistical power. The main result is that the proposed modified Wald intervals maintain and exploit the type I error much better than the intervals of Agresti-Coull, Wilson, and Clopper-Pearson. The interval suggested by Bamber, the Mann-Whitney interval without transformation and also the interval of the binormal AUC are very liberal. For small sample sizes the Wald interval with continuity has a comparable coverage probability as the LT interval and higher power. For large sample sizes the results of the LT interval and of the Wald interval without continuity correction are comparable. If individual patient data is not available, but only the estimated AUC and the total sample size, the modified Wald intervals can be recommended as confidence intervals for the AUC. For small sample sizes the continuity correction should be used.

  9. Hierarchy of low-energy models of the electronic structure of cuprate HTSCs: The role of long-range spin-correlated hops

    NASA Astrophysics Data System (ADS)

    Val'kov, V. V.; Mitskan, V. A.; Dzebisashvili, D. M.; Barabanov, A. F.

    2018-02-01

    It is shown that for the three-band Emery p-d-model that reflects the real structure of the CuO2-plane of high-temperature superconductors in the regime of strong electron correlations, it is possible to carry out a sequence of reductions to the effective models reproducing low-energy features of elementary excitation spectrum and revealing the spin-polaron nature of the Fermi quasiparticles. The first reduction leads to the spin-fermion model in which the subsystem of spin moments, coupled by the exchange interaction and localized on copper ions, strongly interacts with oxygen holes. The second reduction deals with the transformation from the spin-fermion model to the φ-d-exchange model. An important feature of this transformation is the large energy of the φ-d-exchange coupling, which leads to the formation of spin polarons. The use of this fact allows us to carry out the third reduction, resulting in the t ˜-J˜ *-I -model. Its distinctive feature is the importance of spin-correlated hops as compared to the role of such processes in the commonly used t-J*-model derived from the Hubbard model. Based on the comparative analysis of the spectrum of Fermi excitations calculated for the obtained effective models of the CuO2-plane of high-temperature superconductors, the important role of the usually ignored long-range spin-correlated hops is determined.

  10. Topological Transformation of a Metal–Organic Framework Triggered by Ligand Exchange

    DOE PAGES

    Miera, Greco Gonzalez; Gomez, Antonio Bermejo; Chupas, Peter J.; ...

    2017-04-06

    Metal-organic frameworks (MOFs) have shown to be unsuspectedly dynamic. Here we describe the topological interconversion of a new framework in the bio-MOF-100 family (dia-c) into the known isomer (lcs) by doubling the pore volume, which occurs during post-synthesis modifications. During this transformation, re-assembling of the MOF building blocks into a completely different framework occurs, involving breaking/forming of metal-ligand bonds. MOF crystallinity and local structure are retained, as determined by powder X-ray diffraction (PXRD) and pair distribution function (PDF) analyses, respectively. We have exploited the inherent dynamism of bio-MOF-100 by coupling chemical decorations of the framework using solvent-assisted ligand exchange (SALE)more » to the topological change. Following this method and starting from the pristine dense dia-c phase, open lcs-bio-MOF-100 was prepared and functionalized in-situ with an iridium complex (IrL). Alternatively, the dia-c MOF could be modified with wide-ranging amounts of IrL up to ca. 50 mol%, as determined by solution 1H Nuclear Magnetic Resonance (NMR) spectroscopy, by tuning the concentration of the solutions used and with no evidence for isomer interconversion. The single-site nature of the iridium complexes within the MOFs was assessed by X-ray absorption spectroscopy (XAS) and PDF analyses. As a result, ligand exchanges occurred quantitatively at room temperature, with no need of excess of the iridium metallolinker.« less

  11. Topological Transformation of a Metal–Organic Framework Triggered by Ligand Exchange

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miera, Greco Gonzalez; Gomez, Antonio Bermejo; Chupas, Peter J.

    Metal-organic frameworks (MOFs) have shown to be unsuspectedly dynamic. Here we describe the topological interconversion of a new framework in the bio-MOF-100 family (dia-c) into the known isomer (lcs) by doubling the pore volume, which occurs during post-synthesis modifications. During this transformation, re-assembling of the MOF building blocks into a completely different framework occurs, involving breaking/forming of metal-ligand bonds. MOF crystallinity and local structure are retained, as determined by powder X-ray diffraction (PXRD) and pair distribution function (PDF) analyses, respectively. We have exploited the inherent dynamism of bio-MOF-100 by coupling chemical decorations of the framework using solvent-assisted ligand exchange (SALE)more » to the topological change. Following this method and starting from the pristine dense dia-c phase, open lcs-bio-MOF-100 was prepared and functionalized in-situ with an iridium complex (IrL). Alternatively, the dia-c MOF could be modified with wide-ranging amounts of IrL up to ca. 50 mol%, as determined by solution 1H Nuclear Magnetic Resonance (NMR) spectroscopy, by tuning the concentration of the solutions used and with no evidence for isomer interconversion. The single-site nature of the iridium complexes within the MOFs was assessed by X-ray absorption spectroscopy (XAS) and PDF analyses. As a result, ligand exchanges occurred quantitatively at room temperature, with no need of excess of the iridium metallolinker.« less

  12. 75 FR 27605 - Self-Regulatory Organizations; NASDAQ OMX PHLX, Inc.; Notice of Filing and Immediate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    ... Rule Change Relating to One Cent Strike Price Intervals of Foreign Currency Options May 7, 2010... cent ($0.01) for each expiration month for U.S. dollar-settled foreign currency options (``FCOs'') opened for trading on the Exchange.\\3\\ \\3\\ FCOs are also known as World Currency Options (``WCOs...

  13. Computing Relative Free Energies of Solvation Using Single Reference Thermodynamic Integration Augmented with Hamiltonian Replica Exchange

    DTIC Science & Technology

    2010-10-21

    paper assess the reversible works needed to alchemi - cally change each molecule to the benzene core reference state. To automate the alchemical...the alchemi - cal free energies or reversible works, the TI procedure split the interval from the real state of the molecule at λ ) 0 to the reference

  14. 75 FR 21688 - Self-Regulatory Organizations; The NASDAQ Stock Market LLC; Order Granting Accelerated Approval...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ...-Regulatory Organizations; The NASDAQ Stock Market LLC; Order Granting Accelerated Approval of Proposed Rule... 20, 2010. I. Introduction On March 11, 2010, The NASDAQ Stock Market LLC (``Nasdaq'' or ``Exchange.... Strike prices for ETF options are permitted in $1 or greater intervals where the strike price is $200 or...

  15. Inside an Urban Elementary School in the People's Republic of China.

    ERIC Educational Resources Information Center

    Ashmore, Rhea Ann

    Field observations of a visiting foreign exchange scholar (English teacher) and interview responses from teachers and students are the basis for this description of an urban elementary school in Shanghai (People's Republic of China). The school day begins with group exercise, which is repeated at about 2-hour intervals throughout the school day,…

  16. Management of sulcus-fixated single-piece intraocular lens-induced pigmentary glaucoma with 3-piece IOL exchange.

    PubMed

    Rabie, Hossein Mohammad; Esfandiari, Hamed; Rikhtegar, Mohammad Hassan; Hekmat, Vahid

    2018-02-01

    To describe our experience with exchanging sulcus-fixated single-piece intraocular lens (IOL) with 3-piece IOLs for management of pigmentary glaucoma. In this retrospective study, records of patients who underwent sulcus-fixated single-piece IOL exchanged with 3-piece IOLs were retrieved, and demographic and baseline data of patients, type of IOL, pre- and post-IOL exchange BCVA, IOP, number of anti-glaucoma medications, and optic nerve head examination were documented. Baseline and final examinations were analyzed and compared. Mean age of the patients was 59 ± 10 years, and 5 (41.6%) were female. Mean interval between primary cataract extraction operation and IOL exchange was 17 ± 5 months. Nine patients received in sulcus implantation of Alcon SA60AT, and three patients had SN60WF model at the end of primary surgery. BCVA changed insignificantly from 0.06 ± 0.06 logMAR to 0.06 ± 0.06 after IOL exchange. (P = 0.22) IOP was controlled in 8 cases (66.6%), but four cases (33.3%) needed glaucoma surgery to further control glaucoma condition. IOP decreased significantly from preoperative 17 ± 3 to 14 ± 1 mmHg postoperatively. Patients with advanced age and higher baseline IOP were more likely to undergo glaucoma surgery after IOL exchange. (P = 0.07 and 0.00, respectively). single-piece IOL exchange with 3-piece IOL dramatically decreases pigment release and reduces IOP. Those with advanced age and higher IOP are less likely to respond to IOL exchange and may need glaucoma surgery to control high intraocular pressure.

  17. Proceedings of the 7th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The Proceedings contain the papers presented at the Seventh Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting and the edited record of the discussion period following each paper. This meeting provided a forum to promote more effective, efficient, economical and skillful applications of PTTI technology to the many problem areas to which PTTI offers solutions. Specifically the purpose of the meeting is to: disseminate, coordinate, and exchange practical information associated with precise time and frequency; acquaint systems engineers, technicians and managers with precise time and frequency technology and its applications; and review present and future requirements for PTTI.

  18. Neutrino conversion in a neutrino flux: towards an effective theory of collective oscillations

    NASA Astrophysics Data System (ADS)

    Hansen, Rasmus S. L.; Smirnov, Alexei Yu.

    2018-04-01

    Collective oscillations of supernova neutrinos above the neutrino sphere can be completely described by the propagation of individual neutrinos in external potentials and are in this sense a linear phenomenon. An effective theory of collective oscillations can be developed based on certain assumptions about time dependence of these potentials. General conditions for strong flavor transformations are formulated and these transformations can be interpreted as parametric resonance effects induced by periodic modulations of the potentials. We study a simplified and solvable example, where a probe neutrino is propagating in a flux of collinear neutrinos, such that ν ν‑ interactions in the flux are absent. Still, this example retains the main feature—the coherent flavor exchange. Properties of the parametric resonance are studied, and it is shown that integrations over energies and emission points of the flux neutrinos suppress modulations of the potentials and therefore strong transformations. The transformations are also suppressed by changes in densities of background neutrinos and electrons.

  19. Clinical feasibility of exercise-based A-V interval optimization for cardiac resynchronization: a pilot study.

    PubMed

    Choudhuri, Indrajit; MacCarter, Dean; Shaw, Rachael; Anderson, Steve; St Cyr, John; Niazi, Imran

    2014-11-01

    One-third of eligible patients fail to respond to cardiac resynchronization therapy (CRT). Current methods to "optimize" the atrio-ventricular (A-V) interval are performed at rest, which may limit its efficacy during daily activities. We hypothesized that low-intensity cardiopulmonary exercise testing (CPX) could identify the most favorable physiologic combination of specific gas exchange parameters reflecting pulmonary blood flow or cardiac output, stroke volume, and left atrial pressure to guide determination of the optimal A-V interval. We assessed relative feasibility of determining the optimal A-V interval by three methods in 17 patients who underwent optimization of CRT: (1) resting echocardiographic optimization (the Ritter method), (2) resting electrical optimization (intrinsic A-V interval and QRS duration), and (3) during low-intensity, steady-state CPX. Five sequential, incremental A-V intervals were programmed in each method. Assessment of cardiopulmonary stability and potential influence on the CPX-based method were assessed. CPX and determination of a physiological optimal A-V interval was successfully completed in 94.1% of patients, slightly higher than the resting echo-based approach (88.2%). There was a wide variation in the optimal A-V delay determined by each method. There was no observed cardiopulmonary instability or impact of the implant procedure that affected determination of the CPX-based optimized A-V interval. Determining optimized A-V intervals by CPX is feasible. Proposed mechanisms explaining this finding and long-term impact require further study. ©2014 Wiley Periodicals, Inc.

  20. Heat exchanger design for hot air ericsson-brayton piston engine

    NASA Astrophysics Data System (ADS)

    Ďurčanský, P.; Lenhard, R.; Jandačka, J.

    2014-03-01

    One of the solutions without negative consequences for the increasing energy consumption in the world may be use of alternative energy sources in micro-cogeneration. Currently it is looking for different solutions and there are many possible ways. Cogeneration is known for long time and is widely used. But the installations are often large and the installed output is more suitable for cities or industry companies. When we will speak about decentralization, the small machines have to be used. The article deals with the principle of hot-air engines, their use in combined heat and electricity production from biomass and with heat exchangers as primary energy transforming element. In the article is hot air engine presented as a heat engine that allows the conversion of heat into mechanical energy while heat supply can be external. In the contribution are compared cycles of hot-air engine. Then are compared suitable heat exchangers for use with hot air Ericsson-Brayton engine. In the final part is proposal of heat exchanger for use in closed Ericsson-Brayton cycle.

  1. Preparation and performance evaluation of novel alkaline stable anion exchange membranes

    NASA Astrophysics Data System (ADS)

    Irfan, Muhammad; Bakangura, Erigene; Afsar, Noor Ul; Hossain, Md. Masem; Ran, Jin; Xu, Tongwen

    2017-07-01

    Novel alkaline stable anion exchange membranes are prepared from various amounts of N-methyl dipicolylamine (MDPA) and brominated poly (2,6-dimethyl-1,4-phenylene oxide) (BPPO). The dipicolylamine and MDPA are synthesized through condensation reaction and confirmed by 1H NMR spectroscopy. The morphologies of prepared membranes are investigated by atomic force microscopy (AFM), fourier transform infrared spectroscopy (FTIR), 1H NMR spectroscopy and scanning electron microscopy (SEM). The electrochemical and physical properties of AEMs are tested comprising water uptake (WU), ion exchange capacity (IEC), alkaline stability, linear expansion ratio (LER), thermal stability and mechanical stability. The obtained hydroxide conductivity of MDPA-4 is 66.5 mS/cm at 80 °C. The MDPA-4 membrane shows good alkaline stability, high hydroxide conductivity, low methanol permeability (3.43 × 10-7 cm2/s), higher selectivity (8.26 × 107 mS s/cm3), less water uptake (41.1%) and lower linear expansion (11.1%) despite of high IEC value (1.62 mmol/g). The results prove that MDPA membranes have great potential application in anion exchange membrane fuel cell.

  2. New insights into proton surface mobility processes in PEMFC catalysts using isotopic exchange methods.

    PubMed

    Ferreira-Aparicio, Paloma

    2009-09-01

    The surface chemistry and the adsorption/desorption/exchange behavior of a proton-exchange membrane fuel cell catalyst are analyzed as a case study for the development of tailor-made support materials of enhanced performance and stability. By using H2, D2, and CO as probe molecules, the relevance of some surface functional groups of the catalyst support on several diffusion processes taking place during the adsorption is shown. Sulfonic groups associated with the vulcanized carbon black surface have been detected by means of spectroscopic techniques (X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy) and by analysis of the desorbed products during temperature-programmed desorption tests by mass spectrometry. Such hydrophilic species have been observed to favor proton surface mobility and exchange with Pt-adsorbed deuterium even in the presence of adsorbed CO. This behavior is relevant both for the proper characterization of these kinds of catalysts using adsorption probes and for the design of new surface-modified carbon supports, enabling alternative proton-transfer pathways throughout the catalytic layers toward the membrane.

  3. Different ligand exchange solvents effect on the densification of CuIn0.7Ga0.3Se2 prepared using the heating-up method

    NASA Astrophysics Data System (ADS)

    Yang, Chang-Ting; Hsiang, Hsing-I.

    2017-12-01

    The effects of different ligand exchange solvents and heat treatment conditions on the densification and microstructure development of CuIn0.7Ga0.3Se2 (CIGS) crystallites synthesized using the heating-up method were studied in this work. The heat treatment effects on the organic molecules and crystalline structure were investigated using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was observed that oleylamine (OLA) adsorbed onto the CIGS surface was difficult to remove during sintering. Ligand-exchange with m-xylene or 1-hexanethiol can promote the removal of oleylamine adsorbed onto the CIGS surface and prevent the residual carbon from forming during sintering, which leads to grain growth and densification. A dense CuIn0.7Ga0.3Se2 can be obtained using the precursor powders after ligand-exchange with 1-hexanethiol and m-xylene to remove organic molecules and sintering at 600 °C for 2 h under Se atmosphere.

  4. The optimal digital filters of sine and cosine transforms for geophysical transient electromagnetic method

    NASA Astrophysics Data System (ADS)

    Zhao, Yun-wei; Zhu, Zi-qiang; Lu, Guang-yin; Han, Bo

    2018-03-01

    The sine and cosine transforms implemented with digital filters have been used in the Transient electromagnetic methods for a few decades. Kong (2007) proposed a method of obtaining filter coefficients, which are computed in the sample domain by Hankel transform pair. However, the curve shape of Hankel transform pair changes with a parameter, which usually is set to be 1 or 3 in the process of obtaining the digital filter coefficients of sine and cosine transforms. First, this study investigates the influence of the parameter on the digital filter algorithm of sine and cosine transforms based on the digital filter algorithm of Hankel transform and the relationship between the sine, cosine function and the ±1/2 order Bessel function of the first kind. The results show that the selection of the parameter highly influences the precision of digital filter algorithm. Second, upon the optimal selection of the parameter, it is found that an optimal sampling interval s also exists to achieve the best precision of digital filter algorithm. Finally, this study proposes four groups of sine and cosine transform digital filter coefficients with different length, which may help to develop the digital filter algorithm of sine and cosine transforms, and promote its application.

  5. Martensitic and austenitic transformations in core-surface cubic nanoparticles

    NASA Astrophysics Data System (ADS)

    Özüm, S.; Yalçın, O.; Erdem, R.; Bayrakdar, H.; Eker, H. N.

    2015-01-01

    As a continuation of our recently published work, we have used the pair approximation in Kikuchi version to investigate martensitic and austenitic transformations in homogeneous (HM) and composite (CM) cubic nanoparticles (CNPs) based on the Blume-Emery-Griffiths model. A single cubic nanoparticle made of a core surrounded by a surface is considered as shaped in two dimensional (2D) square arrays instead of hexagonal array. From the phase diagrams of HM and CM-CNPs it has been observed that the martensitic-austenitic transformations (MT-AT) occurred. The influence of the exchange coupling and single-ion anisotropy parameters in the model Hamiltonian on the MT-AT is studied and analyzed in comparison with the results for hexagonal nanoparticles. Significant changes of the phase transition points and hysteresis behaviours depending upon the particle structure have been discussed.

  6. Contributing, Exchanging and Linking for Learning: Supporting Web Co-Discovery in One-to-One Environments

    ERIC Educational Resources Information Center

    Liu, Chen-Chung; Don, Ping-Hsing; Chung, Chen-Wei; Lin, Shao-Jun; Chen, Gwo-Dong; Liu, Baw-Jhiune

    2010-01-01

    While Web discovery is usually undertaken as a solitary activity, Web co-discovery may transform Web learning activities from the isolated individual search process into interactive and collaborative knowledge exploration. Recent studies have proposed Web co-search environments on a single computer, supported by multiple one-to-one technologies.…

  7. Internationalization in the Educational System of a Weak State: Examining Multiple Identities of Bosnia and Herzegovina's Higher Education

    ERIC Educational Resources Information Center

    Sabic-El-Rayess, Amra

    2009-01-01

    Higher education has often acted as the nucleus of progressive thought, the instigator of societal transformation, and the center of cultural exchange and understanding. However, in conflict-ridden societies, higher-education systems have shown a proclivity towards the multiple personality syndrome: their ability to solidify, connect and unite…

  8. Critical Literacy Practices in EFL Reading Classroom--An Experimental Study towards Chinese University Students

    ERIC Educational Resources Information Center

    Liu, Yang

    2017-01-01

    English as a world language is more than a way to exchange information but a means to solidify certain social hierarchy and represent certain social interests. English as a Foreign Language (EFL) teachers should instruct critical awareness to empower students to transform social injustice and fulfill responsibilities as global citizens. This…

  9. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Herbert, Christine

    SPEER will provide assistance and develop strategies for successfully deploying best practices to advance energy efficiency on a regional basis through work with state and local governmental entities. SPEER will work with regional stakeholders and DOE to coordinate and assist the development, management, and implementation of market transformation policies and programs that remove implementation barriers, and create regional synergies and facilitate peer-to-peer exchange.

  10. Effect of hydration on the stability of fullerene-like silica molecules

    NASA Astrophysics Data System (ADS)

    Filonenko, O. V.; Lobanov, V. V.

    2011-05-01

    The hydration of fullerene-like silica molecules was studied by the density functional method (exchange-correlation functional B3LYP, basis set 6-31G**). It was demonstrated that completely coordinated structures transform to more stable hydroxylated ones during hydrolysis. These in turn react with H2O molecules with the formation of hydrogen bonds.

  11. Student-Organized College of Education "Educational Research Exchanges" from the Student and Former Student Perspective.

    ERIC Educational Resources Information Center

    Henson, Robin K.; Guthrie, Abbie

    2001-01-01

    Discusses how some colleges of education (COEs) attempt to develop academic climate and facilitate graduate student research activity, addressing the role of student-organized internal research conferences in the transformation of student to social scientist and explicating the benefits of these internal conferences to students, faculty, and COEs.…

  12. BioCore Guide: A Tool for Interpreting the Core Concepts of Vision and Change for Biology Majors

    ERIC Educational Resources Information Center

    Brownell, Sara E.; Freeman, Scott; Wenderoth, Mary Pat; Crowe, Alison J.

    2014-01-01

    "Vision and Change in Undergraduate Biology Education" outlined five core concepts intended to guide undergraduate biology education: 1) evolution; 2) structure and function; 3) information flow, exchange, and storage; 4) pathways and transformations of energy and matter; and 5) systems. We have taken these general recommendations and…

  13. Equations of State of Elements Based on the Generalized Fermi-Thomas Theory

    DOE R&D Accomplishments Database

    Feynman, R. P.; Metropolis, N.; Teller, E.

    1947-04-28

    The Fermi-Thomas model has been used to derive the equation of state of matter at high pressures and at various temperatures. Calculations have been carried out both without and with the exchange terms. Discussion of similarity transformations lead to the virial theorem and to correlation of solutions for different Z-values.

  14. Technically Speaking: Transforming Language Learning through Virtual Learning Environments (MOOs).

    ERIC Educational Resources Information Center

    von der Emde, Silke; Schneider, Jeffrey; Kotter, Markus

    2001-01-01

    Draws on experiences from a 7-week exchange between students learning German at an American college and advanced students of English at a German university. Maps out the benefits to using a MOO (multiple user domains object-oriented) for language learning: a student-centered learning environment structured by such objectives as peer teaching,…

  15. Change and Transformation: The Journey of Our School

    ERIC Educational Resources Information Center

    MacDonald, Beth

    2012-01-01

    According to the author, when Bonnie and Roger Neugebauer honored their school by asking them to be on the cover of "Exchange," she remembered the conferences she had attended over the years when she was a new director. Her favorite was the Child Care Directors conference in 1989, which was held on the island of Oahu, Hawaii. Not only…

  16. From experimental systems to evolutionary biology: an impossible journey?

    PubMed

    Morange, Michel

    2013-01-01

    The historical approach to the sciences has undergone a sea change during recent decades. Maybe the major contribution of Hans-Jörg Rheinberger to this movement was his demonstration of the importance of experimental systems, and of their transformations, in the development of the sciences. To describe these transformations, Hans-Jörg borrows metaphors from evolutionary biology. I want to argue that evolutionary biologists can find in these recent historical studies plenty of models and concepts to address unresolved issues in their discipline. At a time when transdisciplinarity is highly praised, it is useful to provide a precise description of the obstacles that have so far prevented this exchange.

  17. Mutual transformation of light waves by reflection holograms in photorefractive crystals of the 4-bar 3m symmetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Naunyka, V. N.; Shepelevich, V. V., E-mail: vasshep@inbox.ru

    2011-05-15

    The mutual transformation of light waves in the case of their simultaneous diffraction from a bulk reflection phase hologram, which was formed in a cubic photorefractive crystal of the 4-bar 3m symmetry class, has been studied. The indicator surfaces of the polarization-optimized values of the relative intensity of the object wave, which make it possible to determine the amplification of this wave for any crystal cut, are constructed. The linear polarization azimuths at which the energy exchange between the light waves reaches a maximum are found numerically for crystals of different cuts.

  18. Fast measurement of proton exchange membrane fuel cell impedance based on pseudo-random binary sequence perturbation signals and continuous wavelet transform

    NASA Astrophysics Data System (ADS)

    Debenjak, Andrej; Boškoski, Pavle; Musizza, Bojan; Petrovčič, Janko; Juričić, Đani

    2014-05-01

    This paper proposes an approach to the estimation of PEM fuel cell impedance by utilizing pseudo-random binary sequence as a perturbation signal and continuous wavelet transform with Morlet mother wavelet. With the approach, the impedance characteristic in the frequency band from 0.1 Hz to 500 Hz is identified in 60 seconds, approximately five times faster compared to the conventional single-sine approach. The proposed approach was experimentally evaluated on a single PEM fuel cell of a larger fuel cell stack. The quality of the results remains at the same level compared to the single-sine approach.

  19. The formation of 3 alpha- and 3 beta-acetoxytropanes by Datura stramonium transformed root cultures involves two acetyl-CoA-dependent acyltransferases.

    PubMed

    Robins, R J; Bachmann, P; Robinson, T; Rhodes, M J; Yamada, Y

    1991-11-04

    Tropine (tropan-3 alpha-ol) is an intermediate in the formation of hyoscyamine. An acyltransferase activity that can acetylate tropine using acetylcoenzyme A as cosubstrate has been found in transformed root cultures of Datura stramonium. A further acyltransferase activity that acetylates pseudotropine (tropan-3 beta-ol) with acetyl-coenzyme A is also present. These two activities can be partially resolved by anion-exchange chromatography, some fractions containing only the pseudotropine-utilizing activity. The basic properties of these two enzymes are reported and their roles in forming the observed alkaloid spectrum of D. stramonium roots discussed.

  20. Confidence intervals for a difference between lognormal means in cluster randomization trials.

    PubMed

    Poirier, Julia; Zou, G Y; Koval, John

    2017-04-01

    Cluster randomization trials, in which intact social units are randomized to different interventions, have become popular in the last 25 years. Outcomes from these trials in many cases are positively skewed, following approximately lognormal distributions. When inference is focused on the difference between treatment arm arithmetic means, existent confidence interval procedures either make restricting assumptions or are complex to implement. We approach this problem by assuming log-transformed outcomes from each treatment arm follow a one-way random effects model. The treatment arm means are functions of multiple parameters for which separate confidence intervals are readily available, suggesting that the method of variance estimates recovery may be applied to obtain closed-form confidence intervals. A simulation study showed that this simple approach performs well in small sample sizes in terms of empirical coverage, relatively balanced tail errors, and interval widths as compared to existing methods. The methods are illustrated using data arising from a cluster randomization trial investigating a critical pathway for the treatment of community acquired pneumonia.

  1. Pulmonary Vein Antral Isolation and Nonpulmonary Vein Trigger Ablation Are Sufficient to Achieve Favorable Long-Term Outcomes Including Transformation to Paroxysmal Arrhythmias in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation.

    PubMed

    Liang, Jackson J; Elafros, Melissa A; Muser, Daniele; Pathak, Rajeev K; Santangeli, Pasquale; Zado, Erica S; Frankel, David S; Supple, Gregory E; Schaller, Robert D; Deo, Rajat; Garcia, Fermin C; Lin, David; Hutchinson, Mathew D; Riley, Michael P; Callans, David J; Marchlinski, Francis E; Dixit, Sanjay

    2016-11-01

    Transformation from persistent to paroxysmal atrial fibrillation (AF) after ablation suggests modification of the underlying substrate. We examined the nature of initial arrhythmia recurrence in patients with nonparoxysmal AF undergoing antral pulmonary vein isolation and nonpulmonary vein trigger ablation and correlated recurrence type with long-term ablation efficacy after the last procedure. Three hundred and seventeen consecutive patients with persistent (n=200) and long-standing persistent (n=117) AF undergoing first ablation were included. AF recurrence was defined as early (≤6 weeks) or late (>6 weeks after ablation) and paroxysmal (either spontaneous conversion or treated with cardioversion ≤7 days) or persistent (lasting >7 days). During median follow-up of 29.8 (interquartile range: 14.8-49.9) months, 221 patients had ≥1 recurrence. Initial recurrence was paroxysmal in 169 patients (76%) and persistent in 52 patients (24%). Patients experiencing paroxysmal (versus persistent) initial recurrence were more likely to achieve long-term freedom off antiarrhythmic drugs (hazard ratio, 2.2; 95% confidence interval, 1.5-3.2; P<0.0001), freedom on/off antiarrhythmic drugs (hazard ratio, 2.5; 95% confidence interval, 1.6-3.8; P<0.0001), and arrhythmia control (hazard ratio, 5.2; 95% confidence interval, 2.9-9.2; P<0.0001) after last ablation. In patients with persistent and long-standing persistent AF, limited ablation targeting pulmonary veins and documented nonpulmonary vein triggers improves the maintenance of sinus rhythm and reverses disease progression. Transformation to paroxysmal AF after initial ablation may be a step toward long-term freedom from recurrent arrhythmia. © 2016 American Heart Association, Inc.

  2. Microscopic theory of exchange and dipole-exchange spin waves in magnetic thin films

    NASA Astrophysics Data System (ADS)

    Pereira, Joao Milton, Jr.

    The aim of this work is to develop a microscopic theory of bulk and surface spin wave modes (or magnons) in thin films of some specific ordered magnetic materials, particularly antiferromagnets. Both exchange and magnetic dipole-dipole interactions are taken into account, depending on the material and the wavevector regime. First we study the dispersion relations of spin waves for situations in which the dominant interaction is the short-range exchange coupling between the magnetic sites. We begin by investigating ferromagnetic films with a cubic body centered (b.c.c.) crystal structure a surfaces corresponding to (111) crystal planes. The spin wave frequencies are calculated by a method that generalizes previous techniques used for simpler systems, which allows us to find analytical solutions. The results are then compared with recent experimental data for Ni films grown epitaxially on a W substrate. Then we investigate spin waves in antiferromagnetic systems. Calculations are made for the dispersion relations of exchange-dominated spin waves in antiferromagnetic thin films with simple cubic (s.c.) crystal structures, for three different surface orientations, namely (001), (101) and (111). The results are obtained by using a method similar to the one developed for the ferromagnetic film in the previous chapter. We calculate the effect of finite film thickness in coupling the spin wave modes localized near the two surfaces, leading to a splitting of several of the mode branches that occur in the semi-infinite limit. Another aspect that we consider is the influence, for the (101) orientation, of the direction of propagation on the spin wave frequencies, as well as the effect of non-equivalent sublattices in the (111) case. Next, we investigate the spin waves in antiferromagnetic films made of materials in which the long-range dipole-dipole interaction between the magnetic sites is included, along with the exchange coupling. In this case, we employ a Hamiltonian formalism that uses a transformation of the spin operators to creation and annihilation operators. Initially, we calculate the linear dipole-exchange spin wave spectrum, by considering only the bilinear terms in the transformed Hamiltonian. The theory is applied to antiferromagnetic films with s.c. and b.c.c. structures. The higher-order terms are later included by means of a diagrammatic perturbation technique, which allows us to obtain expressions for the damping and energy shift of the spin wave modes in b.c.c. antiferromagnetic films. Numerical results are then shown for ultrathin films of the antiferromagnet MnF2.

  3. Rasch analysis of the UK Functional Assessment Measure in patients with complex disability after stroke.

    PubMed

    Medvedev, Oleg N; Turner-Stokes, Lynne; Ashford, Stephen; Siegert, Richard J

    2018-02-28

    To determine whether the UK Functional Assessment Measure (UK FIM+FAM) fits the Rasch model in stroke patients with complex disability and, if so, to derive a conversion table of Rasch-transformed interval level scores. The sample included a UK multicentre cohort of 1,318 patients admitted for specialist rehabilitation following a stroke. Rasch analysis was conducted for the 30-item scale including 3 domains of items measuring physical, communication and psychosocial functions. The fit of items to the Rasch model was examined using 3 different analytical approaches referred to as "pathways". The best fit was achieved in the pathway where responses from motor, communication and psychosocial domains were summarized into 3 super-items and where some items were split because of differential item functioning (DIF) relative to left and right hemisphere location (χ2 (10) = 14.48, p = 0.15). Re-scoring of items showing disordered thresholds did not significantly improve the overall model fit. The UK FIM+FAM with domain super-items satisfies expectations of the unidimensional Rasch model without the need for re-scoring. A conversion table was produced to convert the total scale scores into interval-level data based on person estimates of the Rasch model. The clinical benefits of interval-transformed scores require further evaluation.

  4. Estimate of standard deviation for a log-transformed variable using arithmetic means and standard deviations.

    PubMed

    Quan, Hui; Zhang, Ji

    2003-09-15

    Analyses of study variables are frequently based on log transformations. To calculate the power for detecting the between-treatment difference in the log scale, we need an estimate of the standard deviation of the log-transformed variable. However, in many situations a literature search only provides the arithmetic means and the corresponding standard deviations. Without individual log-transformed data to directly calculate the sample standard deviation, we need alternative methods to estimate it. This paper presents methods for estimating and constructing confidence intervals for the standard deviation of a log-transformed variable given the mean and standard deviation of the untransformed variable. It also presents methods for estimating the standard deviation of change from baseline in the log scale given the means and standard deviations of the untransformed baseline value, on-treatment value and change from baseline. Simulations and examples are provided to assess the performance of these estimates. Copyright 2003 John Wiley & Sons, Ltd.

  5. A multifractal analysis of equilibrium measures for conformal expanding maps and Moran-like geometric constructions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pesin, Y.; Weiss, H.

    1997-01-01

    In this paper we establish the complete multifractal formalism for equilibrium measures for Holder continuous conformal expanding maps and expanding Markov Moran-like geometric constructions. Examples include Markov maps of an interval, beta transformations of an interval, rational maps with hyperbolic Julia sets, and conformal total endomorphisms. We also construct a Holder continuous homeomorphism of a compact metric space with an ergodic invariant measure of positive entropy for which the dimension spectrum is not convex, and hence the multifractal formalism fails.

  6. A collaborative computer auditing system under SOA-based conceptual model

    NASA Astrophysics Data System (ADS)

    Cong, Qiushi; Huang, Zuoming; Hu, Jibing

    2013-03-01

    Some of the current challenges of computer auditing are the obstacles to retrieving, converting and translating data from different database schema. During the last few years, there are many data exchange standards under continuous development such as Extensible Business Reporting Language (XBRL). These XML document standards can be used for data exchange among companies, financial institutions, and audit firms. However, for many companies, it is still expensive and time-consuming to translate and provide XML messages with commercial application packages, because it is complicated and laborious to search and transform data from thousands of tables in the ERP databases. How to transfer transaction documents for supporting continuous auditing or real time auditing between audit firms and their client companies is a important topic. In this paper, a collaborative computer auditing system under SOA-based conceptual model is proposed. By utilizing the widely used XML document standards and existing data transformation applications developed by different companies and software venders, we can wrap these application as commercial web services that will be easy implemented under the forthcoming application environments: service-oriented architecture (SOA). Under the SOA environments, the multiagency mechanism will help the maturity and popularity of data assurance service over the Internet. By the wrapping of data transformation components with heterogeneous databases or platforms, it will create new component markets composed by many software vendors and assurance service companies to provide data assurance services for audit firms, regulators or third parties.

  7. Ionothermal synthesis and structural transformation targeted by ion exchange in metal-1,3,5-benzenetricarboxylate compounds

    NASA Astrophysics Data System (ADS)

    Xu, Qing-Qing; Liu, Bing; Xu, Ling; Jiao, Huan

    2017-03-01

    Ionothermal reactions of 1,3,5-benzenetricarboxylate acid (H3BTC) and Ni(NO3)2, Co(NO3)2 and Cu(NO3)2 gave two discrete 32-membered ring-like allomers, [M2(HBTC)2(NH2CONH2)2(H2O)4]·3H2O (M=Ni(1), Co(2)) and one layered [Cu2(BTC)Cl(H2O)4] (3). The weak interactions in 1 can be deconstructed to some degree in ion exchange by exploring the factors of divalent and trivalent metal species, metal concentration and soaking time, which are demonstrated by PXRD and N2 absorption. Cu2+ has the highest N2 adsorbance when soaking with 1, and 1 can keep structure stable when Cu2+ below 0.16 mol L-1 and the soaking time within 24d. As Cu2+ beyond 0.16 mol L-1 and the soaking time beyond 24d, the structure of compound 1 starts to transform with the crystal morphology from clear pale green to opaque blue. Ionothermal reactions of compound 1 with different Cu2+ amounts obtained Ni2+-Cu2+ hetero complexes, whose PXRD patterns are similar to that of 3 and EDS indicates Cu2+% increases with Cu2+ additions and close to 100% as Cu2+ being 1.6 mmol. It suggests that 3 is a controlled product and Cu2+ can transform discrete compound 1 into 2D compound 3.

  8. Earthquakes Promote Bacterial Genetic Exchange in Serpentinite Crevices

    NASA Astrophysics Data System (ADS)

    Naoto, Yoshida; Fujiura, Nori

    2009-04-01

    We report the results of our efforts to study the effects of seismic shaking on simulated biofilms within serpentinite fissures. A colloidal solution consisting of recipient bacterial cells (Pseudomonas sp. or Bacillus subtilis), donor plasmid DNA encoded for antibiotic resistance, and chrysotile (an acicular clay mineral that forms in crevices of serpentinite layers) were placed onto an elastic body made from gellan gum, which acted as the biofilm matrix. Silica beads, as rock analogues (i.e., chemically inert mechanical serpentinite), were placed on the gellan surface, which was coated with the colloidal solution. A rolling vibration similar to vibrations generated by earthquakes was applied, and the silica beads moved randomly across the surface of the gellan. This resulted in the recipient cells' acquiring plasmid DNA and thus becoming genetically transformed to demonstrate marked antibiotic resistance. Neither Pseudomonas sp. nor B. subtilis were transformed by plasmid DNA when chrysotile was substituted for by kaolinite or bentonite in the colloidal solution. Tough gellan (1.0%) promoted the introduction of plasmid DNA into Pseudomonas sp., but soft gellan (0.3%) had no such effect. Genetic transformation of bacteria on the surface of gellan by exposure to exogenous plasmid DNA required seismic shaking and exposure to the acicular clay mineral chrysotile. These experimental results suggest that bacterial genetic exchange readily occurs when biofilms that form in crevices of serpentinite are exposed to seismic shaking. Seismic activity may be a key factor in bacterial evolution along with the formation of biofilms within crevices of serpentinite.

  9. Groundwater Discharge of Legacy Nitrogen to River Networks: Linking Regional Groundwater Models to Streambed Groundwater-Surface Water Exchange and Nitrogen Processing

    NASA Astrophysics Data System (ADS)

    Barclay, J. R.; Helton, A. M.; Briggs, M. A.; Starn, J. J.; Hunt, A.

    2017-12-01

    Despite years of management, excess nitrogen (N) is a pervasive problem in many aquatic ecosystems. More than half of surface water in the United States is derived from groundwater, and widespread N contamination in aquifers from decades of watershed N inputs suggest legacy N discharging from groundwater may contribute to contemporary N pollution problems in surface waters. Legacy N loads to streams and rivers are controlled by both regional scale flow paths and fine-scale processes that drive N transformations, such as groundwater-surface water exchange across steep redox gradients that occur at stream bed interfaces. Adequately incorporating these disparate scales is a challenge, but it is essential to understanding legacy N transport and making informed management decisions. We developed a regional groundwater flow model for the Farmington River, a HUC-8 basin that drains to the Long Island Sound, a coastal estuary that suffers from elevated N loads despite decades of management, to understand broad patterns of regional transport. To evaluate and refine the regional model, we used thermal infrared imagery paired with vertical temperature profiling to estimate groundwater discharge at the streambed interface. We also analyzed discharging groundwater for multiple N species to quantify fine scale patterns of N loading and transformation via denitrification at the streambed interface. Integrating regional and local estimates of groundwater discharge of legacy N to river networks should improve our ability to predict spatiotemporal patterns of legacy N loading to and transformation within surface waters.

  10. Interactions between CO2 chemoreflexes and arterial baroreflexes

    NASA Technical Reports Server (NTRS)

    Henry, R. A.; Lu, I. L.; Beightol, L. A.; Eckberg, D. L.

    1998-01-01

    We studied interactions between CO2 chemoreflexes and arterial baroreflexes in 10 supine healthy young men and women. We measured vagal carotid baroreceptor-cardiac reflexes and steady-state fast Fourier transform R-R interval and photoplethysmographic arterial pressure power spectra at three arterial pressure levels (nitroprusside, saline, and phenylephrine infusions) and three end-tidal CO2 levels (3, 4, and 5%, fixed-frequency, large-tidal-volume breathing, CO2 plus O2). Our study supports three principal conclusions. First, although low levels of CO2 chemoreceptor stimulation reduce R-R intervals and R-R interval variability, statistical modeling suggests that this effect is indirect rather than direct and is mediated by reductions of arterial pressure. Second, reductions of R-R intervals during hypocapnia reflect simple shifting of vagally mediated carotid baroreflex responses on the R-R interval axis rather than changes of baroreflex gain, range, or operational point. Third, the influence of CO2 chemoreceptor stimulation on arterial pressure (and, derivatively, on R-R intervals and R-R interval variability) depends critically on baseline arterial pressure levels: chemoreceptor effects are smaller when pressure is low and larger when arterial pressure is high.

  11. A nonclassical Radau collocation method for solving the Lane-Emden equations of the polytropic index 4.75 ≤ α < 5

    NASA Astrophysics Data System (ADS)

    Tirani, M. D.; Maleki, M.; Kajani, M. T.

    2014-11-01

    A numerical method for solving the Lane-Emden equations of the polytropic index α when 4.75 ≤ α ≤ 5 is introduced. The method is based upon nonclassical Gauss-Radau collocation points and Freud type weights. Nonclassical orthogonal polynomials, nonclassical Radau points and weighted interpolation are introduced and are utilized in the interval [0,1]. A smooth, strictly monotonic transformation is used to map the infinite domain x ∈ [0,∞) onto a half-open interval t ∈ [0,1). The resulting problem on the finite interval is then transcribed to a system of nonlinear algebraic equations using collocation. The method is easy to implement and yields very accurate results.

  12. Numerical study of heat transfer characteristics in BOG heat exchanger

    NASA Astrophysics Data System (ADS)

    Yan, Yan; Pfotenhauer, John M.; Miller, Franklin; Ni, Zhonghua; Zhi, Xiaoqin

    2016-12-01

    In this study, a numerical study of turbulent flow and the heat transfer process in a boil-off liquefied natural gas (BOG) heat exchanger was performed. Finite volume computational fluid dynamics and the k - ω based shear stress transport model were applied to simulate thermal flow of BOG and ethylene glycol in a full-sized 3D tubular heat exchanger. The simulation model has been validated and compared with the engineering specification data from its supplier. In order to investigate thermal characteristics of the heat exchanger, velocity, temperature, heat flux and thermal response were studied under different mass flowrates in the shell-side. The shell-side flow pattern is mostly determined by viscous forces, which lead to a small velocity and low temperature buffer area in the bottom-right corner of the heat exchanger. Changing the shell-side mass flowrate could result in different distributions of the shell-side flow. However, the distribution in the BOG will remain in a relatively stable pattern. Heat flux increases along with the shell-side mass flowrate, but the increase is not linear. The ratio of increased heat flux to the mass flow interval is superior at lower mass flow conditions, and the threshold mass flow for stable working conditions is defined as greater than 0.41 kg/s.

  13. Future changes in large-scale transport and stratosphere-troposphere exchange

    NASA Astrophysics Data System (ADS)

    Abalos, M.; Randel, W. J.; Kinnison, D. E.; Garcia, R. R.

    2017-12-01

    Future changes in large-scale transport are investigated in long-term (1955-2099) simulations of the Community Earth System Model - Whole Atmosphere Community Climate Model (CESM-WACCM) under an RCP6.0 climate change scenario. We examine artificial passive tracers in order to isolate transport changes from future changes in emissions and chemical processes. The model suggests enhanced stratosphere-troposphere exchange in both directions (STE), with decreasing tropospheric and increasing stratospheric tracer concentrations in the troposphere. Changes in the different transport processes are evaluated using the Transformed Eulerian Mean continuity equation, including parameterized convective transport. Dynamical changes associated with the rise of the tropopause height are shown to play a crucial role on future transport trends.

  14. FDM study of ion exchange diffusion equation in glass

    NASA Astrophysics Data System (ADS)

    Zhou, Zigang; Yang, Yongjia; Wang, Qiang; Sun, Guangchun

    2009-05-01

    Ion-exchange technique in glass was developed to fabricate gradient refractive index optical devices. In this paper, the Finite Difference Method(FDM), which is used for the solution of ion-diffusion equation, is reported. This method transforms continual diffusion equation to separate difference equation. It unitizes the matrix of MATLAB program to solve the iteration process. The collation results under square boundary condition show that it gets a more accurate numerical solution. Compared to experiment data, the relative error is less than 0.2%. Furthermore, it has simply operation and kinds of output solutions. This method can provide better results for border-proliferation of the hexagonal and the channel devices too.

  15. LETTER TO THE EDITOR: Two-centre exchange integrals for complex exponent Slater orbitals

    NASA Astrophysics Data System (ADS)

    Kuang, Jiyun; Lin, C. D.

    1996-12-01

    The one-dimensional integral representation for the Fourier transform of a two-centre product of B functions (finite linear combinations of Slater orbitals) with real parameters is generalized to include B functions with complex parameters. This one-dimensional integral representation allows for an efficient method of calculating two-centre exchange integrals with plane-wave electronic translational factors (ETF) over Slater orbitals of real/complex exponents. This method is a significant improvement on the previous two-dimensional quadrature method of the integrals. A new basis set of the form 0953-4075/29/24/005/img1 is proposed to improve the description of pseudo-continuum states in the close-coupling treatment of ion - atom collisions.

  16. Two band model for the cuprates

    NASA Astrophysics Data System (ADS)

    Liu, Shiu; White, Steven

    2009-03-01

    We use a numerical canonical transformation approach to derive an effective two-band model for the hole-doped cuprates, which keeps both oxygen and copper orbitals but removes double occupancy from each. A similar model was considered previously by Frenkel, Gooding, Shraiman, and Siggia (PRB 41, number 1, page 350). We compare the numerically derived model with previously obtained analytical results. In addition to the usual hopping terms between oxygens tpp and Cu-Cu exchange terms Jdd, the model also includes a strong copper-oxygen exchange interaction Jpd and a Kondo-like spin-flip oxygen-oxygen hopping term Kpdp. We use the density matrix renormalization group to study the charge, spin, and pairing properties of the derived model on ladder systems.

  17. Solvent exchange in a metal–organic framework single crystal monitored by dynamic in situ X-ray diffraction

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cox, Jordan M.; Walton, Ian M.; Bateman, Gage

    2017-07-25

    Understanding the processes by which porous solid-state materials adsorb and release guest molecules would represent a significant step towards developing rational design principles for functional porous materials. To elucidate the process of liquid exchange in these materials, dynamicin situX-ray diffraction techniques have been developed which utilize liquid-phase chemical stimuli. Using these time-resolved diffraction techniques, the ethanol solvation process in a flexible metal–organic framework [Co(AIP)(bpy) 0.5(H 2O)]·2H 2O was examined. The measurements provide important insight into the nature of the chemical transformation in this system including the presence of a previously unreported neat ethanol solvate structure.

  18. [Neoplastic transformation of mouse fibroblasts under the influence of high-energy protons and gamma-rays].

    PubMed

    Voskanian, K Sh

    2004-01-01

    Oncoginic transformations of mouse fibroblasts C3H10T1/2 after exposure to proton energies 150 and 584 MeV were compared with fibroblast effects of gamma-radiation. Prior to exposure, cell populations (2.7 x 10(3) cells/cm2) were inoculated in plastic vials with the surface area of 75 cm2 and cultivated 11 days. Survivability was determined by comparing the number of cell colonies in irradiated and non-irradiated (control) vials. Transformation rate was calculated by dividing the total transformation focus number by the number of survived cells in a vial. Rate of oncogenic transformations after gamma- and proton (584 MeV) irradiation was essentially identical, i.e. the parameter grew rapidly at the doses < 1 Gy and slowed down at the doses > 1 Gy. In the dose interval between 1 and 5 Gy, transformation rate for proton energy 150 MeV was found low compared with gamma-radiation and proton energy 584 MeV. It is hypothesized that the different transformation rate after exposure to proton energy 150 MeV is linked with the high linear energy transfer as compared with the proton energy of 584 MeV and gamma-radiation.

  19. Wavelet Transform Analysis of the Power Spectrum of Centre of Pressure Signals to Detect the Critical Point Interval of Postural Control

    NASA Astrophysics Data System (ADS)

    Singh, Neeraj Kumar; Snoussi, Hichem; Hewson, David; Duchêne, Jacques

    The aim of this study was to develop a method to detecting the critical point interval (CPI) when sensory feedback is used as part of a closed-loop postural control strategy. Postural balance was evaluated using centre of pressure (COP) displacements from a force plate for 17 control and 10 elderly subjects under eyes open, eyes closed, and vibration conditions. A modified local-maximum-modulus wavelet transform analysis using the power spectrum of COP signals was used to calculate CPI. Lower CPI values indicate increased closed-loop postural control with a quicker response to sensory input. Such a strategy requires greater energy expenditure due to the repeated muscular interventions to remain stable. The CPI for elderly occurred significantly quicker than for controls, indicating tighter control of posture. Similar results were observed for eyes closed and vibration conditions. The CPI parameter can be used to detect differences in postural control due to ageing.

  20. A baseline-free procedure for transformation models under interval censorship.

    PubMed

    Gu, Ming Gao; Sun, Liuquan; Zuo, Guoxin

    2005-12-01

    An important property of Cox regression model is that the estimation of regression parameters using the partial likelihood procedure does not depend on its baseline survival function. We call such a procedure baseline-free. Using marginal likelihood, we show that an baseline-free procedure can be derived for a class of general transformation models under interval censoring framework. The baseline-free procedure results a simplified and stable computation algorithm for some complicated and important semiparametric models, such as frailty models and heteroscedastic hazard/rank regression models, where the estimation procedures so far available involve estimation of the infinite dimensional baseline function. A detailed computational algorithm using Markov Chain Monte Carlo stochastic approximation is presented. The proposed procedure is demonstrated through extensive simulation studies, showing the validity of asymptotic consistency and normality. We also illustrate the procedure with a real data set from a study of breast cancer. A heuristic argument showing that the score function is a mean zero martingale is provided.

  1. Effect of Niobium on Phase Transformations, Mechanical Properties and Corrosion of Supermartensitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    de Oliveira, Mariana Perez; Calderón-Hernández, José Wilmar; Magnabosco, Rodrigo; Hincapie-Ladino, Duberney; Alonso-Falleiros, Neusa

    2017-04-01

    The influence of niobium addition in a supermartensitic stainless steel with 13Cr-5Ni-2Mo has been studied. The steel with Nb tempered at 600 °C for 2 h showed improved mechanical resistance properties and lower degree of sensitization, without compromising elongation and pitting corrosion resistance, when compared to the reference steel. In order to understand the Nb effect in such steel, mainly regarding phase transformation, different tempering time intervals have been studied. The better performance of the SM2MoNb is attributed to the hindering effect that Nb has in the kinetics of the phase transformations during tempering, delaying the precipitation start and coarsening stages of the present phases.

  2. A philosophical theory on human communication and modern physics: e(,2)c(,2)H('2)T energy-exchange and consciousness-change toward humanism, healing, and transformation

    NASA Astrophysics Data System (ADS)

    Jenkins-Tate, Marnishia Laverne

    This dissertation addresses the need for a body of human communication theory that can be useful toward advancing personal and social transformation. Of the humanistic genre, it suggests that there is a need to promote humanism, healing, and personal transformation in the non-clinical settings of everyday living. Three questions guide the effort. First, it asks: what kind of human communication theory might describe some of the underlying dynamics of human interaction, while also suggesting ways to improve the quality of interactions of any related philosophical theory be grounded by some scientific discipline? Then finally, it asks: how might these proposed concepts be captured in a manner that can be useful to human beings in everyday human interaction? Extending the work of modern physics to the realm of human communication, the theory integrates conceptual aspects of quantum theory, relativity theory, communication accommodation theory, and various nonverbal communication theory. Then, it proposes the philosophical framework for a new body of theory which it calls the energy-exchange theory of human communication. Treating human beings as living forms of matter, it suggests that ``energy'' is the life-force that sustains all human beings, and that ``consciousness'' is that qualitative level of development at which energy manifests itself in the human experience. It proposes that human beings have the capacity to exchange energy and influence consciousness during the human communication process, and that these interactions can advance humanism, healing, and transformation-which it proposes are the higher states and levels of human consciousness. Thus, this research effort sought to know and to describe a phenomenon that is the interactive human being; and to suggest useful ways that this volitional being can know and transform itself through human interaction. With verisimilitude as a driving factor in describing human beings as communicators, the research is ontology- centered. It suggests that human beings are most notably creatures of feeling and soul, and that it is through interaction involving these dimensions that one can best come to know the human being. Accordingly, the research employs a hermeneutic phenomenological approach toward participative inquiry and experiential knowing. With practicality as a driving factor in suggesting ways that the human phenomenon can know and transform itself, this work utilizes a pragmatic approach to theory- building. Pragmatism suggests that all theories are approximations that ultimately should be judged on their abilities to truthfully describe phenomena and to solve human problems. Thus, having undergone an inductive progression from data to theory-building, now this work must go from theory to data, such that next steps should involve formal assessment of its verisimilitude and pragmatism based on feedback gained through field research on various persons who may apply the theory and its model to everyday living. (Abstract shortened by UMI.)

  3. Floral-Dip Transformation of Flax (Linum usitatissimum) to Generate Transgenic Progenies with a High Transformation Rate

    PubMed Central

    Bastaki, Nasmah K.; Cullis, Christopher A.

    2014-01-01

    Agrobacterium-mediated plant transformation via floral-dip is a widely used technique in the field of plant transformation and has been reported to be successful for many plant species. However, flax (Linum usitatissimum) transformation by floral-dip has not been reported. The goal of this protocol is to establish that Agrobacterium and the floral-dip method can be used to generate transgenic flax. We show that this technique is simple, inexpensive, efficient, and more importantly, gives a higher transformation rate than the current available methods of flax transformation. In summary, inflorescences of flax were dipped in a solution of Agrobacterium carrying a binary vector plasmid (T-DNA fragment plus the Linum Insertion Sequence, LIS-1) for 1 - 2 min. The plants were laid flat on their side for 24 hr. Then, plants were maintained under normal growth conditions until the next treatment. The process of dipping was repeated 2 - 3 times, with approximately 10 - 14 day intervals between dipping. The T1 seeds were collected and germinated on soil. After approximately two weeks, treated progenies were tested by direct PCR; 2 - 3 leaves were used per plant plus the appropriate T-DNA primers. Positive transformants were selected and grown to maturity. The transformation rate was unexpectedly high, with 50 - 60% of the seeds from treated plants being positive transformants. This is a higher transformation rate than those reported for Arabidopsis thaliana and other plant species, using floral-dip transformation. It is also the highest, which has been reported so far, for flax transformation using other methods for transformation. PMID:25549243

  4. Floral-dip transformation of flax (Linum usitatissimum) to generate transgenic progenies with a high transformation rate.

    PubMed

    Bastaki, Nasmah K; Cullis, Christopher A

    2014-12-19

    Agrobacterium-mediated plant transformation via floral-dip is a widely used technique in the field of plant transformation and has been reported to be successful for many plant species. However, flax (Linum usitatissimum) transformation by floral-dip has not been reported. The goal of this protocol is to establish that Agrobacterium and the floral-dip method can be used to generate transgenic flax. We show that this technique is simple, inexpensive, efficient, and more importantly, gives a higher transformation rate than the current available methods of flax transformation. In summary, inflorescences of flax were dipped in a solution of Agrobacterium carrying a binary vector plasmid (T-DNA fragment plus the Linum Insertion Sequence, LIS-1) for 1 - 2 min. The plants were laid flat on their side for 24 hr. Then, plants were maintained under normal growth conditions until the next treatment. The process of dipping was repeated 2 - 3 times, with approximately 10 - 14 day intervals between dipping. The T1 seeds were collected and germinated on soil. After approximately two weeks, treated progenies were tested by direct PCR; 2 - 3 leaves were used per plant plus the appropriate T-DNA primers. Positive transformants were selected and grown to maturity. The transformation rate was unexpectedly high, with 50 - 60% of the seeds from treated plants being positive transformants. This is a higher transformation rate than those reported for Arabidopsis thaliana and other plant species, using floral-dip transformation. It is also the highest, which has been reported so far, for flax transformation using other methods for transformation.

  5. Community-based health information technology alliances: potential predictors of early sustainability.

    PubMed

    Kern, Lisa M; Wilcox, Adam B; Shapiro, Jason; Yoon-Flannery, Kahyun; Abramson, Erika; Barron, Yolanda; Kaushal, Rainu

    2011-04-01

    To determine potential predictors of sustainability among community-based organizations that are implementing health information technology (HIT) with health information exchange, in a state with significant funding of such organizations. A longitudinal cohort study of community-based organizations funded through the first phase of the $440 million Healthcare Efficiency and Affordability Law for New Yorkers program. We administered a baseline telephone survey in January and February 2007, using a novel instrument with open-ended questions, and collected follow-up data from the New York State Department of Health regarding subsequent funding awarded in March 2008. We used logistic regression to determine associations between 18 organizational characteristics and subsequent funding. All 26 organizations (100%) responded. Having the alliance led by a health information organization (odds ratio [OR] 11.4, P = .01) and having performed a community-based needs assessment (OR 5.1, P = .08) increased the unadjusted odds of subsequent funding. Having the intervention target the long-term care setting (OR 0.14, P = .03) decreased the unadjusted odds of subsequent funding. In the multivariate model, having the alliance led by a health information organization, rather than a healthcare organization, increased the odds of subsequent funding (adjusted OR 6.4; 95% confidence interval 0.8, 52.6; P = .08). Results from this longitudinal study suggest that both health information organizations and healthcare organizations are needed for sustainable HIT transformation.

  6. Important influence of respiration on human R-R interval power spectra is largely ignored

    NASA Technical Reports Server (NTRS)

    Brown, T. E.; Beightol, L. A.; Koh, J.; Eckberg, D. L.

    1993-01-01

    Frequency-domain analyses of R-R intervals are used widely to estimate levels of autonomic neural traffic to the human heart. Because respiration modulates autonomic activity, we determined for nine healthy subjects the influence of breathing frequency and tidal volume on R-R interval power spectra (fast-Fourier transform method). We also surveyed published literature to determine current practices in this burgeoning field of scientific inquiry. Supine subjects breathed at rates of 6, 7.5, 10, 15, 17.1, 20, and 24 breaths/min and with nominal tidal volumes of 1,000 and 1,500 ml. R-R interval power at respiratory and low (0.06-0.14 Hz) frequencies declined significantly as breathing frequency increased. R-R interval power at respiratory frequencies was significantly greater at a tidal volume of 1,500 than 1,000 ml. Neither breathing frequency nor tidal volume influenced average R-R intervals significantly. Our review of studies reporting human R-R interval power spectra showed that 51% of the studies controlled respiratory rate, 11% controlled tidal volume, and 11% controlled both respiratory rate and tidal volume. The major implications of our analyses are that breathing parameters strongly influence low-frequency as well as respiratory frequency R-R interval power spectra and that this influence is largely ignored in published research.

  7. 76 FR 24067 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of Proposed Rule...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-29

    ... Stock Market, LLC Relating to the $2.50 Strike Price Program April 22, 2011. Pursuant to Section 19(b)(1... ability to select option classes on individual stocks for which the intervals of strike prices will be $2... price of the underlying stock in the primary market.\\4\\ The Exchange currently list [sic] series at $2...

  8. Probabilities of Possible Future Prices (Short-Term Energy Outlook Supplement April 2010)

    EIA Publications

    2010-01-01

    The Energy Information Administration introduced a monthly analysis of energy price volatility and forecast uncertainty in the October 2009 Short-Term Energy Outlook (STEO). Included in the analysis were charts portraying confidence intervals around the New York Mercantile Exchange (NYMEX) futures prices of West Texas Intermediate (equivalent to light sweet crude oil) and Henry Hub natural gas contracts.

  9. 78 FR 56253 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-12

    ... Rule Change Relating to $0.50 and $1 Strike Price Intervals for Classes in the Short Term Option Series... options classes that trade in one dollar increments and are in the Short Term Option Series Program... business day, series of options on no more than thirty option classes that expire on each of the next five...

  10. 76 FR 33387 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of Proposed Rule...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... calculates the CBOE Gold ETF Volatility Index (``GVZ''), which is based on the VIX methodology applied to options on the SPDR Gold Trust (``GLD''). The current filing would permit $0.50 strike price intervals for... exchange-traded fund (``ETF'') options. See Rule 1012, Commentary .05(a)(iv). To the extent that the CBOE...

  11. Analysis of the Interactions between Treaties

    DTIC Science & Technology

    1992-04-01

    PROVISIONS Assist ana protect against chemical weapons UIVERSALITY Research, share/exchange chemi- cals, equipment, information rela. Not applicable ting...liability in the event of injury to a Soviet inspector. U.S. escorts maintain the right to prevent Soviet inspectors from undertaking life ...updated continually through notifications for the life of the Treaty and in total at periodic intervals. The START Treaty requires a myriad of

  12. 40 CFR 1065.202 - Data updating, recording, and control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... means. § 1065.514, § 1065.530 Steady-state and ramped-modal duty cycle reference and feedback speeds and... mean value per test interval. § 1065.530, § 1065.545 Diluted exhaust flow rate from a CVS with a heat exchanger upstream of the flow measurement N/A 1 Hz. § 1065.530, § 1065.545 Diluted exhaust flow rate from a...

  13. 77 FR 76135 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-26

    ... 500 Index option series in the pilot: (1) A time series analysis of open interest; and (2) an analysis... issue's total market share value, which is the share price times the number of shares outstanding. These... other series. Strike price intervals would be set no less than 5 points apart. Consistent with existing...

  14. Facility-based constraints to exchange transfusions for neonatal hyperbilirubinemia in resource-limited settings

    PubMed Central

    Mabogunje, Cecilia A; Olaifa, Sarah M; Olusanya, Bolajoko O

    2016-01-01

    Several clinical guidelines for the management of infants with severe neonatal hyperbilirubinemia recommend immediate exchange transfusion (ET) when the risk or presence of acute bilirubin encephalopathy is established in order to prevent chronic bilirubin encephalopathy or kernicterus. However, the literature is sparse concerning the interval between the time the decision for ET is made and the actual initiation of ET, especially in low- and middle-income countries (LMICs) with significant resource constraints but high rates of ET. This paper explores the various stages and potential delays during this interval in complying with the requirement for immediate ET for the affected infants, based on the available evidence from LMICs. The vital role of intensive phototherapy, efficient laboratory and logistical support, and clinical expertise for ET are highlighted. The challenges in securing informed parental consent, especially on religious grounds, and meeting the financial burden of this emergency procedure to facilitate timely ET are examined. Secondary delays arising from post-treatment bilirubin rebound with intensive phototherapy or ET are also discussed. These potential delays can compromise the effectiveness of ET and should provide additional impetus to curtail avoidable ET in LMICs. PMID:27170928

  15. Technical Note: A minimally invasive experimental system for pCO2 manipulation in plankton cultures using passive gas exchange (atmospheric carbon control simulator)

    NASA Astrophysics Data System (ADS)

    Love, Brooke A.; Olson, M. Brady; Wuori, Tristen

    2017-05-01

    As research into the biotic effects of ocean acidification has increased, the methods for simulating these environmental changes in the laboratory have multiplied. Here we describe the atmospheric carbon control simulator (ACCS) for the maintenance of plankton under controlled pCO2 conditions, designed for species sensitive to the physical disturbance introduced by the bubbling of cultures and for studies involving trophic interaction. The system consists of gas mixing and equilibration components coupled with large-volume atmospheric simulation chambers. These chambers allow gas exchange to counteract the changes in carbonate chemistry induced by the metabolic activity of the organisms. The system is relatively low cost, very flexible, and when used in conjunction with semi-continuous culture methods, it increases the density of organisms kept under realistic conditions, increases the allowable time interval between dilutions, and/or decreases the metabolically driven change in carbonate chemistry during these intervals. It accommodates a large number of culture vessels, which facilitate multi-trophic level studies and allow the tracking of variable responses within and across plankton populations to ocean acidification. It also includes components that increase the reliability of gas mixing systems using mass flow controllers.

  16. Street Life and Drug Risk Behaviors Associated with Exchanging Sex Among Male Street Children in Lahore, Pakistan

    PubMed Central

    Towe, Vivian L.; Hasan, Salman ul; Zafar, S. Tariq; Sherman, Susan G.

    2009-01-01

    Background Throughout the developing world, children living on urban streets is a byproduct of economic deprivation. In Lahore, Pakistan, there are an estimated 5,000–7,000 street children. Purpose The study examined HIV risk behaviors and factors associated with exchanging sex among male street children in Lahore, Pakistan. Methods The survey was conducted from August 2003 to March 2004 among 565 registrants, ages 5–19, of Project Smile, a program that aimed to enhance the lives of street children in Lahore. We analyzed the frequency of and correlates of recent (past three months) sex exchange for money, drugs, or goods. Multivariate log-binomial regression was used to evaluate the independent effect of covariates on exchange sex. Results Approximately 40% of participants reported having exchanged sex during the past three months. In multivariate analysis, the factors associated with exchanging sex were living on the street for longer than 48 months (Prevalence Ratio [PR]=1.36, 95% Confidence Interval [CI]: 0.99–1.85), reporting ever having used drugs (PR=1.87, 1.10–3.16), cutting one’s self (PR=1.66, 95% CI: 1.26–2.19), and having heard of HIV/AIDS (PR=1.36, 95% CI: 1.03–1.80) after adjusting for demographic and street life variables. Conclusions We found high rates of sex exchange among a sample of street children in Lahore, Pakistan. The finding that children who have heard about HIV/AIDS are more likely to exchange sex suggests that children at HIV risk talk about HIV, but accuracy of their conversations is unclear. Street children in Pakistan are in great need of HIV education and safe alternatives for generating income. PMID:19237107

  17. Glove and gown effects on intraoperative bacterial contamination.

    PubMed

    Ward, William G; Cooper, Joshua M; Lippert, Dylan; Kablawi, Rawan O; Neiberg, Rebecca H; Sherertz, Robert J

    2014-03-01

    Experiments were performed to determine the risk of bacterial contamination associated with changing outer gloves and using disposable spunlace paper versus reusable cloth gowns. Despite decades of research, there remains a lack of consensus regarding certain aspects of optimal aseptic technique including outer glove exchange while double-gloving and surgical gown type selection. In an initial glove study, 102 surgical team members were randomized to exchange or retain outer gloves 1 hour into clean orthopedic procedures; cultures were obtained 15 minutes later from the palm of the surgeon's dominant gloved hand and from the surgical gown sleeve. Surgical gown type selection was recorded. A laboratory strike-through study investigating bacterial transmission through cloth and paper gowns was performed with coagulase-negative staphylococci. In a follow-up glove study, 251 surgical team members, all wearing paper gowns, were randomized as in the first glove study. Glove study 1 revealed 4-fold higher levels of baseline bacterial contamination (31% vs 7%) on the sleeve of surgical team members wearing cloth gowns than those using paper gowns [odds ratio (95% confidence interval): 4.64 (1.72-12.53); P = 0.0016]. The bacterial strike-through study revealed that 26 of 27 cloth gowns allowed bacterial transmission through the material compared with 0 of 27 paper gowns (P < 0.001). In glove study 2, surgeons retaining outer gloves 1 hour into the case had a subsequent positive glove contamination rate of 23% compared with 13% among surgeons exchanging their original outer glove [odds ratio (95% confidence interval): 1.97 (1.02-3.80); P = 0.0419]. Paper gowns demonstrated less bacterial transmission in the laboratory and lower rates of contamination in the operating room. Disposable paper gowns are recommended for all surgical cases, especially those involving implants, because of the heightened risk of infection. Outer glove exchange just before handling implant materials is also recommended to minimize intraoperative contamination.

  18. Reflections on TAH and the Historian's Role: Reciprocal Exchanges and Transformative Contributions to History Education

    ERIC Educational Resources Information Center

    Long, Kelly Ann

    2006-01-01

    Both the Organization of American Historians (OAH) and The American Historical Association (AHA) have engaged in the debate about reform and improvement of pre-collegiate history education, which has been a hot political issue at least since the 1983 publication of "A Nation at Risk." Both the OAH and the AHA support initiatives that promote the…

  19. "A Gentleman's Handshake": The Role of Social Capital and Trust in Transforming Information into Usable Knowledge

    ERIC Educational Resources Information Center

    Fisher, Rhiannon

    2013-01-01

    This paper explores the role of various social ties in building trust and providing opportunities for information acquisition and knowledge exchange (IAKE). Social capital is used as a vehicle to explore the relationships between farmers and their advisors using bovine tuberculosis (bTB), a major disease facing the English cattle industry, as a…

  20. Impact of WhatsAPP on Learning and Retention of Collocation Knowledge among Iranian EFL Learners

    ERIC Educational Resources Information Center

    Ashiyan, Zahra; Salehi, Hadi

    2016-01-01

    During the recent technological years, language learning has been attempted to transform its path from the conventional methods to instrumental applications. Mobile phone provides people to reach and exchange information through chats (WhatsApp). It is a tool or mode that means the facilities are used for main purposes. The unique features of the…

  1. A World Transformed: How Other Countries Are Preparing Students for the Interconnected World of the 21st Century

    ERIC Educational Resources Information Center

    Stewart, Vivien

    2005-01-01

    Whether by incorporating the study of other nations and cultures into the school curriculum, requiring students to learn foreign languages, or encouraging cross-cultural exchanges, countries around the world are preparing their students for life in the global era. Vivien Stewart describes efforts in Europe, Australia, and Asia and assesses how the…

  2. Investigation of modulation parameters in multiplexing gas chromatography.

    PubMed

    Trapp, Oliver

    2010-10-22

    Combination of information technology and separation sciences opens a new avenue to achieve high sample throughputs and therefore is of great interest to bypass bottlenecks in catalyst screening of parallelized reactors or using multitier well plates in reaction optimization. Multiplexing gas chromatography utilizes pseudo-random injection sequences derived from Hadamard matrices to perform rapid sample injections which gives a convoluted chromatogram containing the information of a single sample or of several samples with similar analyte composition. The conventional chromatogram is obtained by application of the Hadamard transform using the known injection sequence or in case of several samples an averaged transformed chromatogram is obtained which can be used in a Gauss-Jordan deconvolution procedure to obtain all single chromatograms of the individual samples. The performance of such a system depends on the modulation precision and on the parameters, e.g. the sequence length and modulation interval. Here we demonstrate the effects of the sequence length and modulation interval on the deconvoluted chromatogram, peak shapes and peak integration for sequences between 9-bit (511 elements) and 13-bit (8191 elements) and modulation intervals Δt between 5 s and 500 ms using a mixture of five components. It could be demonstrated that even for high-speed modulation at time intervals of 500 ms the chromatographic information is very well preserved and that the separation efficiency can be improved by very narrow sample injections. Furthermore this study shows that the relative peak areas in multiplexed chromatograms do not deviate from conventionally recorded chromatograms. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. Interval estimation and optimal design for the within-subject coefficient of variation for continuous and binary variables

    PubMed Central

    Shoukri, Mohamed M; Elkum, Nasser; Walter, Stephen D

    2006-01-01

    Background In this paper we propose the use of the within-subject coefficient of variation as an index of a measurement's reliability. For continuous variables and based on its maximum likelihood estimation we derive a variance-stabilizing transformation and discuss confidence interval construction within the framework of a one-way random effects model. We investigate sample size requirements for the within-subject coefficient of variation for continuous and binary variables. Methods We investigate the validity of the approximate normal confidence interval by Monte Carlo simulations. In designing a reliability study, a crucial issue is the balance between the number of subjects to be recruited and the number of repeated measurements per subject. We discuss efficiency of estimation and cost considerations for the optimal allocation of the sample resources. The approach is illustrated by an example on Magnetic Resonance Imaging (MRI). We also discuss the issue of sample size estimation for dichotomous responses with two examples. Results For the continuous variable we found that the variance stabilizing transformation improves the asymptotic coverage probabilities on the within-subject coefficient of variation for the continuous variable. The maximum like estimation and sample size estimation based on pre-specified width of confidence interval are novel contribution to the literature for the binary variable. Conclusion Using the sample size formulas, we hope to help clinical epidemiologists and practicing statisticians to efficiently design reliability studies using the within-subject coefficient of variation, whether the variable of interest is continuous or binary. PMID:16686943

  4. Age-dependent biochemical quantities: an approach for calculating reference intervals.

    PubMed

    Bjerner, J

    2007-01-01

    A parametric method is often preferred when calculating reference intervals for biochemical quantities, as non-parametric methods are less efficient and require more observations/study subjects. Parametric methods are complicated, however, because of three commonly encountered features. First, biochemical quantities seldom display a Gaussian distribution, and there must either be a transformation procedure to obtain such a distribution or a more complex distribution has to be used. Second, biochemical quantities are often dependent on a continuous covariate, exemplified by rising serum concentrations of MUC1 (episialin, CA15.3) with increasing age. Third, outliers often exert substantial influence on parametric estimations and therefore need to be excluded before calculations are made. The International Federation of Clinical Chemistry (IFCC) currently recommends that confidence intervals be calculated for the reference centiles obtained. However, common statistical packages allowing for the adjustment of a continuous covariate do not make this calculation. In the method described in the current study, Tukey's fence is used to eliminate outliers and two-stage transformations (modulus-exponential-normal) in order to render Gaussian distributions. Fractional polynomials are employed to model functions for mean and standard deviations dependent on a covariate, and the model is selected by maximum likelihood. Confidence intervals are calculated for the fitted centiles by combining parameter estimation and sampling uncertainties. Finally, the elimination of outliers was made dependent on covariates by reiteration. Though a good knowledge of statistical theory is needed when performing the analysis, the current method is rewarding because the results are of practical use in patient care.

  5. Influence of tea saponin on enhancing accessibility of pyrene and cadmium phytoremediated with Lolium multiflorum in co-contaminated soils.

    PubMed

    Wang, Qian; Liu, Xiaoyan; Zhang, Xinying; Hou, Yunyun; Hu, Xiaoxin; Liang, Xia; Chen, Xueping

    2016-03-01

    Tea saponin (TS), a kind of biodegradable surfactant, was chosen to improve the accessible solubilization of pyrene and cadmium (Cd) in co-contaminated soils cultivated Lolium multiflorum. TS obviously improved the accessibility of pyrene and Cd for L. multiflorum to accelerate the process of accumulation and elimination of the pollutants. The chemical forms of Cd was transformed from Fe-Mn oxides and associated to carbonates fractions into exchangeable fractions by adding TS in single Cd and pyrene-Cd contaminated soils. Moreover, the chemical forms of pyrene were transformed from associated fraction into bioaccessible fraction by adding TS in pyrene and pyrene-Cd contaminated soils. In pyrene-Cd contaminated soil, the exchangeable fraction of Cd was hindered in the existence of pyrene, and bioaccessible fraction of pyrene was promoted by the cadmium. Besides, in the process of the pyrene degradation and Cd accumulation, the effect could be improved by the elongation of roots with adding TS, and the microorganism activity was stimulated by TS to accelerate the removal of pollutions. Therefore, Planting L. multiflorum combined with adding TS would be an effective method on the phytoremediation of organics and heavy metals co-contaminated soils.

  6. Ca2+ transport in plant cells and mechanisms of transformation of phytochrome-induced photosignals

    NASA Astrophysics Data System (ADS)

    Volotovski, Igor D.

    1995-01-01

    The recent data on the influence of phytochrome on the efficiency of Ca2+ translocation across the membranes of oat protoplasts are given. Ca2+ uptake in the protoplasts was shown to be influenced by the red light (R) illumination. This effect was reverted by the following far-red light (FR) illumination. To elucidate the sensitivity to phytochrome-controlling action the screening between the mechanisms of Ca2+ transport across the plasma membranes of oat protoplasts, Na+/Ca2+ and Ca2+/H+ exchangers, Ca2+-pump and Ca2+-channel was done. It was established that phytochrome modulated the activity of Na+/Ca2+-exchanger and Ca2+-pump. The light-mediated oscillations of cytoplasmic Ca2+ concentration in the oat protoplasts were demonstrated using fluorescence probe quin2 loaded into the cells and laser monitoring of fluorescence signal. The evidences were obtained that the oscillations were not the result of the elevation of cytoplasmic Ca2+ concentration and had no connection with Ca2+ pool of mitochondria. The possibility of the relation between the Ca2+ oscillations and phosphoinositide metabolism in plant cell membranes is analyzed. The mechanisms of transformation of primary phytochrome signal into biological effects were discussed.

  7. Standard Biological Parts Knowledgebase

    PubMed Central

    Galdzicki, Michal; Rodriguez, Cesar; Chandran, Deepak; Sauro, Herbert M.; Gennari, John H.

    2011-01-01

    We have created the Knowledgebase of Standard Biological Parts (SBPkb) as a publically accessible Semantic Web resource for synthetic biology (sbolstandard.org). The SBPkb allows researchers to query and retrieve standard biological parts for research and use in synthetic biology. Its initial version includes all of the information about parts stored in the Registry of Standard Biological Parts (partsregistry.org). SBPkb transforms this information so that it is computable, using our semantic framework for synthetic biology parts. This framework, known as SBOL-semantic, was built as part of the Synthetic Biology Open Language (SBOL), a project of the Synthetic Biology Data Exchange Group. SBOL-semantic represents commonly used synthetic biology entities, and its purpose is to improve the distribution and exchange of descriptions of biological parts. In this paper, we describe the data, our methods for transformation to SBPkb, and finally, we demonstrate the value of our knowledgebase with a set of sample queries. We use RDF technology and SPARQL queries to retrieve candidate “promoter” parts that are known to be both negatively and positively regulated. This method provides new web based data access to perform searches for parts that are not currently possible. PMID:21390321

  8. Dual-Emission SG7@MOF Sensor via SC-SC Transformation: Enhancing the Formation of Excimer Emission and the Range and Sensitivity of Detection.

    PubMed

    Fu, Hong-Ru; Wu, Xiao-Xia; Ma, Lu-Fang; Wang, Fei; Zhang, Jian

    2018-05-30

    In this study, a water stable metal-organic framework FIR-53 is applied as a single-crystal container for anion exchange. The exceptional chemical stability and low crystallographic symmetry of FIR-53 makes it possible to determine anionic guests. Through ion exchange and single-crystal to single-crystal (SC-SC) transformation, 8-hydroxypyrene-1,3,6-trisulfonate (SG7, solvent green 7, ion form as SG7 3- ) is introduced into the pores of FIR-53 to obtain SG7@FIR-53. Because of the spatial confinement and partition effect, SG7@FIR-53 shows the bright exciter emission of SG7 ions. Interestingly, the composite SG7@FIR-53 exhibits a sensitive fluorescence quenching response against Cr 2 O 7 2- and MnO 4 - in aqueous solution. Especially, the detection limit toward MnO 4 - is as low as 0.12 ppb, which is the smallest value to date. Moreover, the prepared SG7@FIR-53 film also displays a broad response to nitro explosives in vapor/aqueous phase. Compared with the results of FIR-53, the range and sensitivity were greatly improved.

  9. Electromagnetic field focusing by a plane multilayer structure with a Veselago medium

    NASA Astrophysics Data System (ADS)

    Fisanov, V. V.

    2011-12-01

    The focusing properties of a system of plane layers of a Veselago medium divided by vacuous intervals are investigated by the coordinate transformation method. The role of real and virtual foci in the mechanism of focusing by a multilayered lens is considered.

  10. Cation Exchange Reactions for Improved Quality and Diversity of Semiconductor Nanocrystals

    NASA Astrophysics Data System (ADS)

    Beberwyck, Brandon James

    Observing the size and shape dependent physical properties of semiconductor nanocrystals requires synthetic methods capable of not only composition and crystalline phase control but also molecular scale uniformity for a particle consisting of tens to hundreds of thousands of atoms. The desire for synthetic methods that produce uniform nanocrystals of complex morphologies continues to increase as nanocrystals find roles in commercial applications, such as biolabeling and display technologies, that are simultaneously restricting material compositions. With these constraints, new synthetic strategies that decouple the nanocrystal's chemical composition from its morphology are necessary. This dissertation explores the cation exchange reaction of colloidal semiconductor nanocrystals, a template-based chemical transformation that enables the interconversion of nanocrystals between a variety of compositions while maintaining their size dispersity and morphology. Chapter 1 provides an introduction to the versatility of this replacement reaction as a synthetic method for semiconductor nanocrystals. An overview of the fundamentals of the cation exchange reaction and the diversity of products that are achievable is presented. Chapter 2 examines the optical properties of nanocrystal heterostructures produced through cation exchange reactions. The deleterious impact of exchange on the photoluminescence is correlated to residual impurities and a simple annealing protocol is demonstrated to achieve photoluminescence yields comparable to samples produced by conventional methods. Chapter 3 investigates the extension of the cation exchange reaction beyond ionic nanocrystals. Covalent III-V nanocrystal of high crystallinity and low size dispersity are synthesized by the cation exchange of cadmium pnictide nanocrystals with group 13 ions. Lastly, Chapter 4 highlights future studies to probe cation exchange reactions in colloidal semiconductor nanocrystals and progress that needs to be made for its adoption as a routine synthetic approach.

  11. Long-Term Geomagnetically Induced Current Observations From New Zealand: Peak Current Estimates for Extreme Geomagnetic Storms

    NASA Astrophysics Data System (ADS)

    Rodger, Craig J.; Mac Manus, Daniel H.; Dalzell, Michael; Thomson, Alan W. P.; Clarke, Ellen; Petersen, Tanja; Clilverd, Mark A.; Divett, Tim

    2017-11-01

    Geomagnetically induced current (GIC) observations made in New Zealand over 14 years show induction effects associated with a rapidly varying horizontal magnetic field (dBH/dt) during geomagnetic storms. This study analyzes the GIC observations in order to estimate the impact of extreme storms as a hazard to the power system in New Zealand. Analysis is undertaken of GIC in transformer number six in Islington, Christchurch (ISL M6), which had the highest observed currents during the 6 November 2001 storm. Using previously published values of 3,000 nT/min as a representation of an extreme storm with 100 year return period, induced currents of 455 A were estimated for Islington (with the 95% confidence interval range being 155-605 A). For 200 year return periods using 5,000 nT/min, current estimates reach 755 A (confidence interval range 155-910 A). GIC measurements from the much shorter data set collected at transformer number 4 in Halfway Bush, Dunedin, (HWB T4), found induced currents to be consistently a factor of 3 higher than at Islington, suggesting equivalent extreme storm effects of 460-1,815 A (100 year return) and 460-2,720 A (200 year return). An estimate was undertaken of likely failure levels for single-phase transformers, such as HWB T4 when it failed during the 6 November 2001 geomagnetic storm, identifying that induced currents of 100 A can put such transformer types at risk of damage. Detailed modeling of the New Zealand power system is therefore required to put this regional analysis into a global context.

  12. Theoretical calculations of high-pressure phases of NiF2: An ab initio constant-pressure study

    NASA Astrophysics Data System (ADS)

    Kürkçü, Cihan; Merdan, Ziya; Öztürk, Hülya

    2016-12-01

    We have studied the structural properties of the antiferromagnetic NiF2 tetragonal structure with P42/ mnm symmetry using density functional theory (DFT) under rapid hydrostatic pressure up to 400 GPa. For the exchange correlation energy we used the local density approximation (LDA) of Ceperley and Alder (CA). Two phase transformations are successfully observed through the simulations. The structures of XF2-type compounds crystallize in rutile-type structure. NiF2 undergoes phase transformations from the tetragonal rutile-type structure with space group P42/ mnm to orthorhombic CaCl2-type structure with space group Pnnm and from this orthorhombic phase to monoclinic structure with space group C2/ m at 152 GPa and 360 GPa, respectively. These phase changes are also studied by total energy and enthalpy calculations. According to these calculations, we perdict these phase transformations at about 1.85 and 30 GPa.

  13. Biofilm-induced bioclogging produces sharp interfaces in hyporheic flow, redox conditions, and microbial community structure

    NASA Astrophysics Data System (ADS)

    Caruso, Alice; Boano, Fulvio; Ridolfi, Luca; Chopp, David L.; Packman, Aaron

    2017-05-01

    Riverbed sediments host important biogeochemical processes that play a key role in nutrient dynamics. Sedimentary nutrient transformations are mediated by bacteria in the form of attached biofilms. The influence of microbial metabolic activity on the hydrochemical conditions within the hyporheic zone is poorly understood. We present a hydrobiogeochemical model to assess how the growth of heterotrophic and autotrophic biomass affects the transport and transformation of dissolved nitrogen compounds in bed form-induced hyporheic zones. Coupling between hyporheic exchange, nitrogen metabolism, and biomass growth leads to an equilibrium between permeability reduction and microbial metabolism that yields shallow hyporheic flows in a region with low permeability and high rates of microbial metabolism near the stream-sediment interface. The results show that the bioclogging caused by microbial growth can constrain rates and patterns of hyporheic fluxes and microbial transformation rate in many streams.

  14. Kinetic stable Cr isotopic fractionation between aqueous Cr(III)-Cl-H2O complexes at 25 °C: Implications for Cr(III) mobility and isotopic variations in modern and ancient natural systems

    NASA Astrophysics Data System (ADS)

    Babechuk, Michael G.; Kleinhanns, Ilka C.; Reitter, Elmar; Schoenberg, Ronny

    2018-02-01

    The stable Cr isotope fractionation preserved in natural substances has been attributed predominantly to Cr(III)-Cr(VI) redox transformations. However, non-redox reaction pathways (e.g., ligand-promoted dissolution, ligand exchange, adsorption of Cr(III)) are liable to contribute to isotopic fractionation in natural systems given that soluble Cr(III)-ligands have been directly documented or modeled in several marine, continental, and hydrothermal environments. This study isolates the stable Cr isotope fractionation accompanying Cl-H2O ligand exchange during the transformation of three aqueous species in the Cr(III)-Cl-H2O system, [CrCl2(H2O)4]+aq (abr. CrCl2+ or S1), [CrCl(H2O)5]2+aq (abr. CrCl2+ or S2), and [Cr(H2O)6]3+aq (abr. Cr3+ or S3), at low pH (≤2). In dilute HCl (0.01 to 1 M), Cr3+ is the kinetically favoured species and transformation of CrCl2+ to CrCl2+ to Cr3+ via 2 steps of dechlorination/hydrolyzation begins immediately upon dissolution of a Cr(III)-Cl solid. Individual species are separated with cation exchange chromatography at different stages of transformation and inter- and intra-species (across an elution peak of one species) isotopic fractionation of up to 1 and 2‰ (δ53/52Cr), respectively, is documented. Comparison of peak elution characteristics with Cr-Cl-H-O isotopologue mass abundances suggests mass-dependent sorting of isotopologues alone cannot explain intra-species fractionation, supporting a previously published proposal that preferential adsorption of light Cr isotopes on the resin is driven by vibrational energy effects. The transformation of CrCl2+ to CrCl2+ is faster than CrCl2+ to Cr3+ and the rates of both transformations increase with solution pH. Preferential reaction of light Cr(III) isotopes into product species occurs during each transformation, consistent with closed-system, kinetic fractionation during Cl-H2O ligand exchange. Inter-species fractionation is assessed using time-series experiments beginning from the dissolution of two Cr(III)-Cl solids (dried NIST SRM979 standard and commercial CrCl3·6H2O salt) in 0.01 M HCl (pH ≈ 2). The ε53/52Cr(CrCl2+/CrCl2+) for the CrCl2+ to CrCl2+ reaction is -0.19‰ (SRM979) and -0.38‰ (salt) and the ε53/52Cr(Cr3+/CrCl2+) for the CrCl2+ to Cr3+ reaction is consistent for both experiments at -0.49‰ (SRM979) and -0.51‰ (salt). Experiments where SRM979 is dissolved in 0.1 and 1 M HCl for a longer aging period provide preliminary evidence that the Cr3+/CrCl2+ Cr(III) isotopic fractionation scales with HCl concentration (transformation rate). Chromium(III) dissolved in 6 M HCl and aged 5 months still yields an inter-species Cr isotope distribution that is apparently inherited from kinetic effects (light Cr isotopes in Cr3+), attesting to the slow development of inter-species isotopic equilibrium, which instead predicts progressively heavier Cr isotopes from CrCl2+ to CrCl2+ to Cr3+. The kinetic Cr(III) isotopic fractionation documented herein is proposed to be relevant to understanding systems where aqueous Cr(III)-Cl species may be temporarily stable (e.g., metamorphic and hydrothermal systems or lateritic weathering). Further, the complexation of Cr(III) with other ligands (e.g., CO32-, organics), combined with additional kinetic effects of Cr(III) potentially occurring in soils or sediment, must be explored prior to establishing the significance of empirical stable Cr isotope signatures in marine and continental environments. Further understanding of non-redox effects may lead to stable Cr isotopes developing as a proxy for system pH or ligand chemistry.

  15. The Impact of Transformational Leadership on Safety Climate and Individual Safety Behavior on Construction Sites.

    PubMed

    Shen, Yuzhong; Ju, Chuanjing; Koh, Tas Yong; Rowlinson, Steve; Bridge, Adrian J

    2017-01-05

    Unsafe acts contribute dominantly to construction accidents, and increasing safety behavior is essential to reduce accidents. Previous research conceptualized safety behavior as an interaction between proximal individual differences (safety knowledge and safety motivation) and distal contextual factors (leadership and safety climate). However, relatively little empirical research has examined this conceptualization in the construction sector. Given the cultural background of the sample, this study makes a slight modification to the conceptualization and views transformational leadership as an antecedent of safety climate. Accordingly, this study establishes a multiple mediator model showing the mechanisms through which transformational leadership translates into safety behavior. The multiple mediator model is estimated by the structural equation modeling (SEM) technique, using individual questionnaire responses from a random sample of construction personnel based in Hong Kong. As hypothesized, transformational leadership has a significant impact on safety climate which is mediated by safety-specific leader-member exchange (LMX), and safety climate in turn impacts safety behavior through safety knowledge. The results suggest that future safety climate interventions should be more effective if supervisors exhibit transformational leadership, encourage construction personnel to voice safety concerns without fear of retaliation, and repeatedly remind them about safety on the job.

  16. The Impact of Transformational Leadership on Safety Climate and Individual Safety Behavior on Construction Sites

    PubMed Central

    Shen, Yuzhong; Ju, Chuanjing; Koh, Tas Yong; Rowlinson, Steve; Bridge, Adrian J.

    2017-01-01

    Unsafe acts contribute dominantly to construction accidents, and increasing safety behavior is essential to reduce accidents. Previous research conceptualized safety behavior as an interaction between proximal individual differences (safety knowledge and safety motivation) and distal contextual factors (leadership and safety climate). However, relatively little empirical research has examined this conceptualization in the construction sector. Given the cultural background of the sample, this study makes a slight modification to the conceptualization and views transformational leadership as an antecedent of safety climate. Accordingly, this study establishes a multiple mediator model showing the mechanisms through which transformational leadership translates into safety behavior. The multiple mediator model is estimated by the structural equation modeling (SEM) technique, using individual questionnaire responses from a random sample of construction personnel based in Hong Kong. As hypothesized, transformational leadership has a significant impact on safety climate which is mediated by safety-specific leader–member exchange (LMX), and safety climate in turn impacts safety behavior through safety knowledge. The results suggest that future safety climate interventions should be more effective if supervisors exhibit transformational leadership, encourage construction personnel to voice safety concerns without fear of retaliation, and repeatedly remind them about safety on the job. PMID:28067775

  17. Commensurate Superstructure of the {Cu(NO3)(H2O)}(HTae)(Bpy) Coordination Polymer: An Example of 2D Hydrogen-Bonding Networks as Magnetic Exchange Pathway.

    PubMed

    Fernández de Luis, Roberto; Larrea, Edurne S; Orive, Joseba; Lezama, Luis; Arriortua, María I

    2016-11-21

    The average and commensurate superstructures of the one-dimensional coordination polymer {Cu(NO 3 )(H 2 O)}(HTae)(Bpy) (H 2 Tae = 1,1,2,2-tetraacetylethane, Bpy = 4,4'-bipyridine) were determined by single-crystal X-ray diffraction, and the possible symmetry relations between the space group of the average structure and the superstructure were checked. The crystal structure consists in parallel and oblique {Cu(HTae)(Bpy)} zigzag metal-organic chains stacked along the [100] crystallographic direction. The origin of the fivefold c axis in the commensurate superstructure is ascribed to a commensurate modulation of the coordination environment of the copper atoms. The commensurately ordered nitrate groups and coordinated water molecules establish a two-dimensional hydrogen-bonding network. Moreover, the crystal structure shows a commensurate to incommensurate transition at room temperature. The release of the coordination water molecules destabilizes the crystal framework, and the compound shows an irreversible structure transformation above 100 °C. Despite the loss of crystallinity, the spectroscopic studies indicate that the main building blocks of the crystal framework are retained after the transformation. The hydrogen-bonding network not only plays a crucial role stabilizing the crystal structure but also is an important pathway for magnetic exchange transmission. In fact, the magnetic susceptibility curves indicate that after the loss of coordinated water molecules, and hence the collapse of the hydrogen-bonding network, the weak anti-ferromagnetic coupling observed in the initial compound is broken. The electron paramagnetic resonance spectra are the consequence of the average signals from Cu(II) with different orientations, indicating that the magnetic coupling is effective between them. In fact, X- and Q-band data are reflecting different situations; the X-band spectra show the characteristics of an exchange g-tensor, while the Q-band signals are coming from both the exchange and the molecular g-tensors.

  18. Transformation zone location and intraepithelial neoplasia of the cervix uteri.

    PubMed Central

    Autier, P.; Coibion, M.; Huet, F.; Grivegnee, A. R.

    1996-01-01

    We examined the relationship between the frequency of premalignant lesions of the cervix and location of the transformation zone on the cervix among 8758 women as assessed using cervicography. An endo- and exocervical smear test was performed at the same time. Women with smear test classified CIN I or more were recalled and any abnormal area was biopsied under colposcopy. The transformation zone was located on the exocervix in 94% of women younger than 25 years old; as age increased, the proportion of women with a transformation zone located on the exocervix steadily decreased to reach less than 2% after 64 years old. As compared with women having a transformation zone in the endocervical canal, the age-adjusted likelihood of discovering a histologically proven dysplastic lesion was 1.8 times more frequent among women with a transformation zone located on the exocervix (95% confidence interval 1.1-2.9). This higher frequency seemed not attributable to a lower sensitivity of the smear test when the transformation zone was hidden. The results also showed that deliveries tended significantly to maintain the transformation zone on the exocervix. Parity is a known risk factor for cervix cancer, but the mechanism by which it favours malignant lesions remain unknown. Our results suggest that with increasing numbers of livebirths, the transformation zone is directly exposed for longer periods to external agents involved in dysplastic lesions. PMID:8695371

  19. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, Jing-Yun, E-mail: jyunwu@ncnu.edu.tw; Tsai, Chi-Jou; Chang, Ching-Yun

    A Zn(II)−salicylaldimine complex [Zn(L{sup salpyca})(H{sub 2}O)]{sub n} (1, where H{sub 2}L{sup salpyca}=4-hydroxy-3-(((pyridin-2-yl)methylimino)methyl)benzoic acid), with a one-dimensional (1D) chain structure, has been successfully converted to a discrete Ni(II)−salicylaldimine complex [Ni(L{sup salpyca})(H{sub 2}O){sub 3}] (2) and an infinite Cu(II)−salicylaldimine complex ([Cu(L{sup salpyca})]·3H{sub 2}O){sub n} (3) through a metal-ion exchange induced structural transformation process. However, such processes do not worked by Mn(II) and Co(II) ions. Solid-state structure analyses reveal that complexes 1–3 form comparable coordinative or supramolecular zigzag chains running along the crystallographic [201] direction. In addition, replacing Zn(II) ion by Ni(II) and Cu(II) ions caused changes in coordination environment and sphere ofmore » metal centers, from a 5-coordinate intermediate geometry of square pyramidal and trigonal bipyramidal in 1 to a 6-coordinate octahedral geometry in 2, and to a 4-coordiante square planar geometry in 3. This study shows that metal-ion exchange serves as a very efficient way of forming new coordination complexes that may not be obtained through direct synthesis. - Graphical abstract: A Zn(II)−salicylaldimine zigzag chain has been successfully converted to a Ni(II)−salicylaldimine supramolecular zigzag chain and a Cu(II)−salicylaldimine coordinative zigzag chain through metal-ion exchange induced structural transformations, which is not achieved by Mn(II) and Co(II) ions.« less

  20. Implicit measurement of the latent heat in a magnetocaloric NiMnIn Heusler alloy

    NASA Astrophysics Data System (ADS)

    Ghahremani, Mohammadreza; ElBidweihy, Hatem; Bennett, Lawrence H.; Della Torre, Edward; Zou, Min; Johnson, Francis

    2013-05-01

    The latent heat linked with the first-order transformation of a NiMnIn Heusler alloy has been studied through direct measurements of the adiabatic temperature change, ΔTad, during magnetization process. The experimental procedure used guarantees independent data points and negates any contribution of hysteretic losses to the magnetocaloric effect. Thus, the differences between the magnitudes of ΔTad measurements during the magnetization with the initial temperature change directions from low-to-high and high-to-low are solely attributed to the latent heat exchange, which accompanies the irreversible structural first-order transformation. An estimate of the latent heat inducing such differences is about 0.292 J/g.

  1. Frequent fire alters nitrogen transformations in ponderosa pine stands of the inland Northwest

    Treesearch

    Thomas H. DeLuca; Sala Anna

    2006-01-01

    Recurrent, low-severity fire in ponderosa pine (Pinus ponderosa)/interior Douglas-fir (Pseudotsuga menziesii var. glauca) forests is thought to have directly influenced nitrogen (N) cycling and availability. However, no studies to date have investigated the influence of natural fire intervals on soil processes in undisturbed...

  2. Evaluating a nursing erasmus exchange experience: Reflections on the use and value of the Nominal Group Technique for evaluation.

    PubMed

    Cunningham, Sheila

    2017-09-01

    This paper discusses the use of Nominal Group Technique (NGT) for European nursing exchange evaluation at one university. The NGT is a semi-quantitative evaluation method derived from the Delphi method popular in the 1970s and 1980s. The NGT was modified from the traditional version retaining the structured cycles and but adding a broader group discussion. The NGT had been used for 2 successive years but required analysis and evaluation itself for credibility and 'fit' for purpose which is presented here. It aimed to explore nursing students' exchange experiences and aid programme development futures exchanges and closure from exchange. Results varied for the cohorts and students as participants enthusiastically engaged generating ample data which they ranked and categorised collectively. Evaluation of the NGT itself was two fold: by the programme team who considered purpose, audience, inclusivity, context and expertise. Secondly, students were asked for their thoughts using a graffiti board. Students avidly engaged with NGT but importantly also reported an effect from the process itself as an opportunity to reflect and share their experiences. The programme team concluded the NGT offered a credible evaluation tool which made use of authentic student voice and offered interactive group processes. Pedagogially, it enabled active reflection thus aiding reorientation back to the United Kingdom and awareness of 'transformative' consequences of their exchange experiences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Stochastic Simulation of Isotopic Exchange Mechanisms for Fe(II)-Catalyzed Recrystallization of Goethite.

    PubMed

    Zarzycki, Piotr; Rosso, Kevin M

    2017-07-05

    Understanding Fe(II)-catalyzed transformations of Fe(III)-(oxyhydr)oxides is critical for correctly interpreting stable isotopic distributions and for predicting the fate of metal ions in the environment. Recent Fe isotopic tracer experiments have shown that goethite undergoes rapid recrystallization without phase change when exposed to aqueous Fe(II). The proposed explanation is oxidation of sorbed Fe(II) and reductive Fe(II) release coupled 1:1 by electron conduction through crystallites. Given the availability of two tracer exchange data sets that explore pH and particle size effects (e.g., Handler et al. Environ. Sci. Technol. 2014 , 48 , 11302 - 11311 ; Joshi and Gorski Environ. Sci. Technol. 2016 , 50 , 7315 - 7324 ), we developed a stochastic simulation that exactly mimics these experiments, while imposing the 1:1 constraint. We find that all data can be represented by this model, and unifying mechanistic information emerges. At pH 7.5 a rapid initial exchange is followed by slower exchange, consistent with mixed surface- and diffusion-limited kinetics arising from prominent particle aggregation. At pH 5.0 where aggregation and net Fe(II) sorption are minimal, that exchange is quantitatively proportional to available particle surface area and the density of sorbed Fe(II) is more readily evident. Our analysis reveals a fundamental atom exchange rate of ∼10 -5 Fe nm -2 s -1 , commensurate with some of the reported reductive dissolution rates of goethite, suggesting Fe(II) release is the rate-limiting step in the conduction mechanism during recrystallization.

  4. Effect of match-run frequencies on the number of transplants and waiting times in kidney exchange.

    PubMed

    Ashlagi, Itai; Bingaman, Adam; Burq, Maximilien; Manshadi, Vahideh; Gamarnik, David; Murphey, Cathi; Roth, Alvin E; Melcher, Marc L; Rees, Michael A

    2018-05-01

    Numerous kidney exchange (kidney paired donation [KPD]) registries in the United States have gradually shifted to high-frequency match-runs, raising the question of whether this harms the number of transplants. We conducted simulations using clinical data from 2 KPD registries-the Alliance for Paired Donation, which runs multihospital exchanges, and Methodist San Antonio, which runs single-center exchanges-to study how the frequency of match-runs impacts the number of transplants and the average waiting times. We simulate the options facing each of the 2 registries by repeated resampling from their historical pools of patient-donor pairs and nondirected donors, with arrival and departure rates corresponding to the historical data. We find that longer intervals between match-runs do not increase the total number of transplants, and that prioritizing highly sensitized patients is more effective than waiting longer between match-runs for transplanting highly sensitized patients. While we do not find that frequent match-runs result in fewer transplanted pairs, we do find that increasing arrival rates of new pairs improves both the fraction of transplanted pairs and waiting times. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

  5. Sister chromatid exchange in children of Seventh-Day Adventists and matched controls.

    PubMed

    Hermansen, R; Waksvik, H; Fønnebø, V

    1991-03-01

    The low risk of cancer in Seventh-Day Adventists (SDAs) has been suggested to be due to genetic selection. To investigate this claim we examined the sister chromatid exchange (SCE) frequency in peripheral blood lymphocytes in 16 SDA children in Tromsø, all aged 0.5-8 years and 16 controls matched for sex and age. In 12 of 16 pairs, the SDA children had a lower SCE frequency than the controls. The mean difference was 4.06 (95% confidence interval -17.02-8.89, P = 0.51). There was no sex difference, and no correlation between age and SCE frequency. The genetic starting point with regard to SCE frequency seems to be the same for SDA children and controls.

  6. The development of new ferromagnetic shape memory alloys in Ni-Mn-Ga system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chernenko, V.A.; Kokorin, V.V.; Vitenko, I.N.

    1995-10-15

    The Ferromagnetic Heusler alloy Ni{sub 2}MnGa is known to undergo a structural phase transformation of martensitic type. Thermoelastic nature, shape memory effect (SME) and superelasticity were sound to be intrinsic to this transformation. In this work the authors present the results of the investigation of the following problems: how M{sub s}, the thermal hysteresis, Curie temperature, transformation heat are affected by the composition variation in the Ni-Mn-Ga alloy system in a concentration interval for each component of about 10 at. %. This work was performed to make sure that the new family of Ni-Mn-Ga based shape memory alloys (SMA) withmore » a wide variety of structural and magnetic properties is actually elaborated.« less

  7. 75 FR 17820 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of a Proposed Rule...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-07

    ... SECURITIES AND EXCHANGE COMMISSION [Release No. 34-61812; File No. SR-Phlx-2010-49] Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of a Proposed Rule Change by NASDAQ OMX PHLX, Inc. To Establish $2.50 Strike Price Intervals for Options on the NASDAQ Internet Index \\SM\\ March 31, 2010. Pursuant to Section 19(b)(1) of...

  8. 26 CFR 1.1232-3 - Gain upon sale or exchange of obligations issued at a discount after December 31, 1954.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... under section 451 and the regulations thereunder either: (1) At fixed periodic intervals of one year or... price of an investment unit shall be allocated to the individual elements of the unit on the basis of... standard bond tables. Any reasonable method may be used in selecting an obligation for comparative purposes...

  9. 26 CFR 1.1232-3 - Gain upon sale or exchange of obligations issued at a discount after December 31, 1954.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... under section 451 and the regulations thereunder either: (1) At fixed periodic intervals of one year or... price of an investment unit shall be allocated to the individual elements of the unit on the basis of... standard bond tables. Any reasonable method may be used in selecting an obligation for comparative purposes...

  10. 26 CFR 1.1232-3 - Gain upon sale or exchange of obligations issued at a discount after December 31, 1954.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... under section 451 and the regulations thereunder either: (1) At fixed periodic intervals of one year or... price of an investment unit shall be allocated to the individual elements of the unit on the basis of... standard bond tables. Any reasonable method may be used in selecting an obligation for comparative purposes...

  11. 76 FR 12775 - Self-Regulatory Organizations; C2 Options Exchange, Incorporated; Notice of Filing of a Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... series in the pilot: (1) A time series analysis of open interest; and (2) An analysis of the distribution... times the number of shares outstanding. These are summed for all 500 stocks and divided by a... below $3.00 and $0.10 for all other series. Strike price intervals would be set no less than 5 points...

  12. Ventilator-associated pneumonia using a heated humidifier or a heat and moisture exchanger: a randomized controlled trial [ISRCTN88724583].

    PubMed

    Lorente, Leonardo; Lecuona, María; Jiménez, Alejandro; Mora, María L; Sierra, Antonio

    2006-01-01

    Some guidelines to prevent ventilator-associated pneumonia (VAP) do not establish a recommendation for the preferential use of either heat and moisture exchangers (HMEs) or heated humidifiers (HHs), while other guidelines clearly advocate the use of HMEs. The aim of this study was to determine the incidence of VAP associated with HHs or HMEs. A randomized study was conducted in the intensive care unit of a university hospital involving patients expected to require mechanical ventilation for >5 days. Patients were assigned to two groups; one group received HH and the other group received HME. Tracheal aspirate samples were obtained on endotracheal intubation, then twice a week, and finally on extubation, in order to diagnose VAP. Throat swabs were taken on admission to the intensive care unit, then twice a week, and finally at discharge from the intensive care unit in order to classify VAP as primary endogenous, secondary endogenous, or exogenous. A total of 120 patients were assigned to HMEs (60 patients) and HHs (60 patients); 16 patients received mechanical ventilation for less than five days and were excluded from the analysis. Data analysis of the remaining 104 patients (53 HMEs and 51 HHs) showed no significant differences between groups regarding sex, age, Acute Physiology and Chronic Health Evaluation II score, pre-VAP use of antibiotics, days on mechanical ventilation, and diagnosis group. VAP was found in eight of 51 (15.69%) patients in the HH group and in 21 of 53 (39.62%) patients in the HME group (P = 0.006). The median time free of VAP was 20 days (95% confidence interval, 13.34-26.66) for the HH group and was 42 days (95% confidence interval, 35.62-48.37) for the HME group (P <0.001). Cox regression analysis showed the HME as a risk factor for VAP (hazard rate, 16.2; 95% confidence interval, 4.54-58.04; P < 0.001). The patients mechanically ventilated during more than 5 days developed a lower incidence of VAP with a heated humidifier than heat and moisture exchanger.

  13. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Barnes, Taylor A.; Kurth, Thorsten; Carrier, Pierre

    Here, we present an algorithm and implementation for the parallel computation of exact exchange in Quantum ESPRESSO (QE) that exhibits greatly improved strong scaling. QE is an open-source software package for electronic structure calculations using plane wave density functional theory, and supports the use of local, semi-local, and hybrid DFT functionals. Wider application of hybrid functionals is desirable for the improved simulation of electronic band energy alignments and thermodynamic properties, but the computational complexity of evaluating the exact exchange potential limits the practical application of hybrid functionals to large systems and requires efficient implementations. We demonstrate that existing implementations ofmore » hybrid DFT that utilize a single data structure for both the local and exact exchange regions of the code are significantly limited in the degree of parallelization achievable. We present a band-pair parallelization approach, in which the calculation of exact exchange is parallelized and evaluated independently from the parallelization of the remainder of the calculation, with the wavefunction data being efficiently transformed on-the-fly into a form that is optimal for each part of the calculation. For a 64 water molecule supercell, our new algorithm reduces the overall time to solution by nearly an order of magnitude.« less

  14. Scaling properties of foreign exchange volatility

    NASA Astrophysics Data System (ADS)

    Gençay, Ramazan; Selçuk, Faruk; Whitcher, Brandon

    2001-01-01

    In this paper, we investigate the scaling properties of foreign exchange volatility. Our methodology is based on a wavelet multi-scaling approach which decomposes the variance of a time series and the covariance between two time series on a scale by scale basis through the application of a discrete wavelet transformation. It is shown that foreign exchange rate volatilities follow different scaling laws at different horizons. Particularly, there is a smaller degree of persistence in intra-day volatility as compared to volatility at one day and higher scales. Therefore, a common practice in the risk management industry to convert risk measures calculated at shorter horizons into longer horizons through a global scaling parameter may not be appropriate. This paper also demonstrates that correlation between the foreign exchange volatilities is the lowest at the intra-day scales but exhibits a gradual increase up to a daily scale. The correlation coefficient stabilizes at scales one day and higher. Therefore, the benefit of currency diversification is the greatest at the intra-day scales and diminishes gradually at higher scales (lower frequencies). The wavelet cross-correlation analysis also indicates that the association between two volatilities is stronger at lower frequencies.

  15. Design and Implementation of Geothermal Energy Systems at West Chester University

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cuprak, Greg

    West Chester University has launched a comprehensive transformation of its campus heating and cooling systems from traditional fossil fuels (coal, oil and natural gas) to geothermal. This change will significantly decrease the institution’s carbon footprint and serve as a national model for green campus efforts. The institution has designed a phased series of projects to build a district geo-exchange system with shared well fields, central pumping station and distribution piping to provide the geo-exchange water to campus buildings as their internal building HVAC systems is changed to be able to use the geo-exchange water. This project addresses the US Departmentmore » of Energy Office of Energy Efficiency and Renewable Energy (EERE) goal to invest in clean energy technologies that strengthen the economy, protect the environment, and reduce dependence on foreign oil. In addition, this project advances EERE’s efforts to establish geothermal energy as an economically competitive contributor to the US energy supply.« less

  16. Sulfidation behavior of ZnFe2O4 roasted with pyrite: Sulfur inducing and sulfur-oxygen interface exchange mechanism

    NASA Astrophysics Data System (ADS)

    Min, Xiaobo; Zhou, Bosheng; Ke, Yong; Chai, Liyuan; Xue, Ke; Zhang, Chun; Zhao, Zongwen; Shen, Chen

    2016-05-01

    The sulfidation roasting behavior was analyzed in detail to reveal the reaction mechanism. Information about the sulfidation reaction, including phase transformation, ionic migration behavior and morphological change, were obtained by XRD, 57Fe Mossbauer spectroscopy, XPS and SEM analysis. The results showed that the sulfidation of zinc ferrite is a process of sulfur inducing and sulfur-oxygen interface exchange. This process can be divided into six stages: decomposition of FeS2, formation of the oxygen-deficient environment, migration of O2- induced by S2(g), formation of ZnFe2O4-δ, migration of Fe2+ accompanied by the precipitation of ZnO, and the sulfur-oxygen interface exchange reaction. The sulfidation products were zinc blende, wurtzite, magnetite and a fraction of zinc-bearing magnetite. These findings can provide theoretical support for controlling the process during which the recovery of Zn and Fe is achieved through the combined flotation-magnetic separation process.

  17. Random isotropic one-dimensional XY-model

    NASA Astrophysics Data System (ADS)

    Gonçalves, L. L.; Vieira, A. P.

    1998-01-01

    The 1D isotropic s = ½XY-model ( N sites), with random exchange interaction in a transverse random field is considered. The random variables satisfy bimodal quenched distributions. The solution is obtained by using the Jordan-Wigner fermionization and a canonical transformation, reducing the problem to diagonalizing an N × N matrix, corresponding to a system of N noninteracting fermions. The calculations are performed numerically for N = 1000, and the field-induced magnetization at T = 0 is obtained by averaging the results for the different samples. For the dilute case, in the uniform field limit, the magnetization exhibits various discontinuities, which are the consequence of the existence of disconnected finite clusters distributed along the chain. Also in this limit, for finite exchange constants J A and J B, as the probability of J A varies from one to zero, the saturation field is seen to vary from Γ A to Γ B, where Γ A(Γ B) is the value of the saturation field for the pure case with exchange constant equal to J A(J B) .

  18. How Ag Nanospheres Are Transformed into AgAu Nanocages

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moreau, Liane M.; Schurman, Charles A.; Kewalramani, Sumit

    Bimetallic hollow, porous noble metal nanoparticles are of broad interest for biomedical, optical and catalytic applications. The most straightforward method for preparing such structures involves the reaction between HAuCl4 and well-formed Ag particles, typically spheres, cubes, or triangular prisms, yet the mechanism underlying their formation is poorly understood at the atomic scale. By combining in situ nanoscopic and atomic-scale characterization techniques (XAFS, SAXS, XRF, and electron microscopy) to follow the process, we elucidate a plausible reaction pathway for the conversion of citrate-capped Ag nanospheres to AgAu nanocages; importantly, the hollowing event cannot be explained by the nanoscale Kirkendall effect, normore » by Galvanic exchange alone, two processes that have been previously proposed. We propose a modification of the bulk Galvanic exchange process that takes into account considerations that can only occur with nanoscale particles. This nanoscale Galvanic exchange process explains the novel morphological and chemical changes associated with the typically observed hollowing process.« less

  19. Optimized effective potential in real time: Problems and prospects in time-dependent density-functional theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mundt, Michael; Kuemmel, Stephan

    2006-08-15

    The integral equation for the time-dependent optimized effective potential (TDOEP) in time-dependent density-functional theory is transformed into a set of partial-differential equations. These equations only involve occupied Kohn-Sham orbitals and orbital shifts resulting from the difference between the exchange-correlation potential and the orbital-dependent potential. Due to the success of an analog scheme in the static case, a scheme that propagates orbitals and orbital shifts in real time is a natural candidate for an exact solution of the TDOEP equation. We investigate the numerical stability of such a scheme. An approximation beyond the Krieger-Li-Iafrate approximation for the time-dependent exchange-correlation potential ismore » analyzed.« less

  20. A structural study of the complex between neuroepithelial cell transforming gene 1 (Net1) and RhoA reveals a potential anticancer drug hot spot.

    PubMed

    Petit, Alain-Pierre; Garcia-Petit, Christel; Bueren-Calabuig, Juan A; Vuillard, Laurent M; Ferry, Gilles; Boutin, Jean A

    2018-06-08

    The GTPase RhoA is a major player in many different regulatory pathways. RhoA catalyzes GTP hydrolysis, and its catalysis is accelerated when RhoA forms heterodimers with proteins of the guanine nucleotide exchange factor (GEF) family. Neuroepithelial cell transforming gene 1 (Net1) is a RhoA-interacting GEF implicated in cancer, but the structural features supporting the RhoA/Net1 interaction are unknown. Taking advantage of a simple production and purification process, here we solved the structure of a RhoA/Net1 heterodimer with X-ray crystallography at 2-Å resolution. Using a panel of several techniques, including molecular dynamics simulations, we characterized the RhoA/Net1 interface. Moreover, deploying an extremely simple peptide-based scanning approach, we found that short peptides (penta- to nonapeptides) derived from the protein/protein interaction region of RhoA could disrupt the RhoA/Net1 interaction and thereby diminish the rate of nucleotide exchange. The most inhibitory peptide, EVKHF, spanning residues 102-106 in the RhoA sequence, displayed an IC 50 of ∼100 μm without further modifications. The peptides identified here could be useful in further investigations of the RhoA/Net1 interaction region. We propose that our structural and functional insights might inform chemical approaches for transforming the pentapeptide into an optimized pseudopeptide that antagonizes Net1-mediated RhoA activation with therapeutic anticancer potential. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Expert Meeting Report: Transforming Existing Buildings through New Media - An Idea Exchange

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hunt, Stacy

    This report describes results of a Building America expert meeting on September 13, 2011, in Las Vegas, Nevada, hosted by the Building America Retrofit Alliance (BARA). This meeting provided a forum for presentations and discussions on the use of new media to work with remodelers and retrofit projects to improve energy efficiency and deliver research results from the Building America program to remodelers.

  2. Expert Meeting Report: Transforming Existing Buildings through New Media--An Idea Exchange

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hunt, S.

    This report describes results of a Building America expert meeting on September 13, 2011, in Las Vegas, Nevada, hosted by the Building America Retrofit Alliance (BARA). This meeting provided a forum for presentations and discussions on the use of new media to work with remodelers and retrofit projects to improve energy efficiency and deliver research results from the Building America program to remodelers.

  3. School Library 2.0: Say Good-Bye to Your Mother's School Library. The Web Is All about New Possibilities

    ERIC Educational Resources Information Center

    Harris, Christopher

    2006-01-01

    Blogs and the whole gamut of interactive, Web-based tools are redefining how we connect with people and content on the Internet. This is the widely discussed next step known as Web 2.0, a truly revolutionary concept in which pervasive interactivity, where multitudes of users online actively exchange or contribute content, will transform the very…

  4. Sorption of strontium-90 from fresh waters during sulfate modification of barium manganite

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ryzhen`kov, A.P.; Egorov, Yu.V.

    1995-11-01

    Recovery of strontium-90 with barium manganite from fresh waters (natural fresh waters of open basins) can be increased by adding agents that contain sulfate ions and thus modify the sorbent and chemically bind the sorbate. The treatment results in a heterogeneous anion-exchange transformation of barium manganite into barium sulfate-manganese dioxide and in simultaneous absorptive coprecipitation of strontium sulfate (microcomponent).

  5. Hiding in plain sight: communication theory in implementation science.

    PubMed

    Manojlovich, Milisa; Squires, Janet E; Davies, Barbara; Graham, Ian D

    2015-04-23

    Poor communication among healthcare professionals is a pressing problem, contributing to widespread barriers to patient safety. The word "communication" means to share or make common. In the literature, two communication paradigms dominate: (1) communication as a transactional process responsible for information exchange, and (2) communication as a transformational process responsible for causing change. Implementation science has focused on information exchange attributes while largely ignoring transformational attributes of communication. In this paper, we debate the merits of encompassing both paradigms. We conducted a two-staged literature review searching for the concept of communication in implementation science to understand how communication is conceptualized. Twenty-seven theories, models, or frameworks were identified; only Rogers' Diffusion of Innovations theory provides a definition of communication and includes both communication paradigms. Most models (notable exceptions include Diffusion of Innovations, The Ottawa Model of Research Use, and Normalization Process Theory) describe communication as a transactional process. But thinking of communication solely as information transfer or exchange misrepresents reality. We recommend that implementation science theories (1) propose and test the concept of shared understanding when describing communication, (2) acknowledge that communication is multi-layered, identify at least a few layers, and posit how identified layers might affect the development of shared understanding, (3) acknowledge that communication occurs in a social context, providing a frame of reference for both individuals and groups, (4) acknowledge the unpredictability of communication (and healthcare processes in general), and (5) engage with and draw on work done by communication theorists. Implementation science literature has conceptualized communication as a transactional process (when communication has been mentioned at all), thereby ignoring a key contributor to implementation intervention success. When conceptualized as a transformational process, the focus of communication moves to shared understanding and is grounded in human interactions and the way we go about constructing knowledge. Instead of hiding in plain sight, we suggest explicitly acknowledging the role that communication plays in our implementation efforts. By using both paradigms, we can investigate when communication facilitates implementation, when it does not, and how to improve it so that our implementation and clinical interventions are embraced by clinicians and patients alike.

  6. Carbon Transformations and Source - Sink Dynamics along a River, Marsh, Estuary, Ocean Continuum

    NASA Astrophysics Data System (ADS)

    Anderson, I. C.; Crosswell, J.; Czapla, K.; Van Dam, B.

    2017-12-01

    Estuaries, the transition zone between land and the coastal ocean, are highly dynamic systems in which carbon sourced from watersheds, marshes, atmosphere, and ocean may be transformed, sequestered, or exported. The net fate of carbon in estuaries, governed by the interactions of biotic and physical drivers varying on spatial and temporal scales, is currently uncertain because of limited observational data. In this study, conducted in a temperate, microtidal, and shallow North Carolina USA estuary, carbon exchanges via river, tributary, and fringing salt marsh, air-water fluxes, sediment C accumulation, and metabolism were monitored over two-years, with sharply different amounts of rainfall. Air-water CO2 fluxes and metabolic variables were simultaneously measured in channel and shoal by conducting high-resolution surveys at dawn, dusk and the following dawn. Marsh CO2 exchanges, sediment C inputs, and lateral exports of DIC and DOC were also measured. Carbon flows between estuary regions and export to the coastal ocean were calculated by quantifying residual transport of DIC and TOC down-estuary as flows were modified by sources, sinks and internal transformations. Variation in metabolic rates, CO2, TOC and DIC exchanges were large when determined for short time and limited spatial scales. However, when scaled to annual and whole estuarine scales, variation tended to decrease because of counteracting metabolic rates and fluxes between channel and shoal or between seasons. Although overall salt marshes accumulated OC, they were a negligible source of DIC and DOC to the estuary, and net inputs of C to the marsh were mainly derived from sediment OC. These results, as observed in other observational studies of estuaries, show that riverine input, light, temperature and metabolism are major controls on carbon cycling. Comparison of our results with other types of estuaries varying in depth, latitude, and nutrification demonstrates large discrepancies underscoring the limitations of current sampling designs, models and datasets in representing system-scale diversity; thus, a more practical approach may be to choose a small number of representative coastal systems, coordinate research efforts to quantify the relevant fluxes and constrain a range of environmental conditions that influence carbon cycling.

  7. Restricted Collision List method for faster Direct Simulation Monte-Carlo (DSMC) collisions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Macrossan, Michael N., E-mail: m.macrossan@uq.edu.au

    The ‘Restricted Collision List’ (RCL) method for speeding up the calculation of DSMC Variable Soft Sphere collisions, with Borgnakke–Larsen (BL) energy exchange, is presented. The method cuts down considerably on the number of random collision parameters which must be calculated (deflection and azimuthal angles, and the BL energy exchange factors). A relatively short list of these parameters is generated and the parameters required in any cell are selected from this list. The list is regenerated at intervals approximately equal to the smallest mean collision time in the flow, and the chance of any particle re-using the same collision parameters inmore » two successive collisions is negligible. The results using this method are indistinguishable from those obtained with standard DSMC. The CPU time saving depends on how much of a DSMC calculation is devoted to collisions and how much is devoted to other tasks, such as moving particles and calculating particle interactions with flow boundaries. For 1-dimensional calculations of flow in a tube, the new method saves 20% of the CPU time per collision for VSS scattering with no energy exchange. With RCL applied to rotational energy exchange, the CPU saving can be greater; for small values of the rotational collision number, for which most collisions involve some rotational energy exchange, the CPU may be reduced by 50% or more.« less

  8. Characteristics of a gun exchange program, and an assessment of potential benefits

    PubMed Central

    Romero, M.; Wintemute, G.; Vernick, J.

    1998-01-01

    Objectives—To describe a gun exchange program and assess potential benefits for participants and host communities. Methods—Mail survey of participants in a Sacramento, California gun exchange program, August 1993; the response rate was 79%. Comparative data were obtained from nationwide polls of gun owners. Results—Most (62%) respondents were men; 40% were more than 55 years old; none was less than 25. Concern that children might find and use the gun was the most frequently cited reason for participating (46% of respondents). Of 141 firearms exchanged, 72% were handguns; 23% of respondents indicated that the guns they turned in were not in working order. Of respondents who owned a gun at the time of the program (rather than those who owned no guns and turned in a gun owned by someone else), 41% owned no guns after participating; the prevalence of handgun ownership declined from 79% to 32%. Those who continued to own guns were as likely as gun owners nationwide to keep a gun loaded in the house (odds ratio (OR) 0.9, 95% confidence interval (CI) 0.4 to 1.7) or to carry a gun with them (OR 1.5, 95% CI 0.6 to 3.8). Conclusions—Gun exchange programs may reduce risk for firearm violence among some participants, but a number of factors limit their overall benefits to host communities. PMID:9788092

  9. A multiple chamber, semicontinuous, crop carbon dioxide exchange system: design, calibration, and data interpretation

    NASA Technical Reports Server (NTRS)

    van Iersel, M. W.; Bugbee, B.

    2000-01-01

    Long-term, whole crop CO2 exchange measurements can be used to study factors affecting crop growth. These factors include daily carbon gain, cumulative carbon gain, and carbon use efficiency, which cannot be determined from short-term measurements. We describe a system that measures semicontinuously crop CO2 exchange in 10 chambers over a period of weeks or months. Exchange of CO2 in every chamber can be measured at 5 min intervals. The system was designed to be placed inside a growth chamber, with additional environmental control provided by the individual gas exchange chambers. The system was calibrated by generating CO2 from NaHCO3 inside the chambers, which indicated that accuracy of the measurements was good (102% and 98% recovery for two separate photosynthesis systems). Since the systems measure net photosynthesis (P-net, positive) and dark respiration(R-dark, negative), the data can be used to estimate gross photosynthesis, daily carbon gain, cumulative carbon gain, and carbon use efficiency. Continuous whole-crop measurements are a valuable tool that complements leaf photosynthesis measurements. Multiple chambers allow for replication and comparison among several environmental or cultural treatments that may affect crop growth. Example data from a 2 week study with petunia (Petunia x hybrida Hort. Vilm.-Andr.) are presented to illustrate some of the capabilities of this system.

  10. High charge state carbon and oxygen ions in Earth's equatorial quasi-trapping region

    NASA Technical Reports Server (NTRS)

    Christon, S. P.; Hamilton, D. C.; Gloeckler, G.; Eastmann, T. E.

    1994-01-01

    Observations of energetic (1.5 - 300 keV/e) medium-to-high charge state (+3 less than or equal to Q less than or equal to +7) solar wind origin C and O ions made in the quasi-trapping region (QTR) of Earth's magnetosphere are compared to ion trajectories calculated in model equatorial magnetospheric magnetic and electric fields. These comparisons indicate that solar wind ions entering the QTR on the nightside as an energetic component of the plasma sheet exit the region on the dayside, experiencing little or no charge exchange on the way. Measurements made by the CHarge Energy Mass (CHEM) ion spectrometer on board the Active Magnetospheric Particle Tracer Explorer/Charge Composition Explorer (AMPTE/CCE) spacecraft at 7 less than L less than 9 from September 1984 to January 1989 are the source of the new results contained herein: quantitative long-term determination of number densities, average energies, energy spectra, local time distributions, and their variation with geomagnetic disturbance level as indexed by Kp. Solar wind primaries (ions with charge states unchanged) and their secondaries (ions with generally lower charge states produced from primaries in the magnetosphere via charge exchange)are observed throughout the QTR and have distinctly different local time variations that persist over the entire 4-year analysis interval. During Kp larger than or equal to 3 deg intervals, primary ion (e.g., O(+6)) densities exhibit a pronounced predawn maximum with average energy minimum and a broad near-local-noon density minimum with average energy maximum. Secondary ion (e.g., O(+5)) densities do not have an identifiable predawn peak, rather they have a broad dayside maximum peaked in local morning and a nightside minimum. During Kp less than or equal to 2(-) intervals, primary ion density peaks are less intense, broader in local time extent, and centered near midnight, while secondary ion density local time variations diminish. The long-time-interval baseline helps to refine and extend previous observations; for example, we show that ionospheric contribution to O(+3)) is negligible. Through comparison with model ion trajectories, we interpret the lack of pronounced secondary ion density peaks colocated with the primary density peaks to indicate that: (1) negligible charge exchange occurs at L greater than 7, that is, solar wind secondaries are produced at L less than 7, and (2) solar wind secondaries do not form a significant portion of the plasma sheet population injected into the QTR. We conclude that little of the energetic solar wind secondary ion population is recirculated through the magnetosphere.

  11. [Effects of stabilization treatment on migration and transformation of heavy metals in mineral waste residues].

    PubMed

    Zhao, Shu-Hua; Chen, Zhi-Liang; Zhang, Tai-Ping; Pan, Wei-Bin; Peng, Xiao-Chun; Che, Rong; Ou, Ying-Juan; Lei, Guo-Jian; Zhou, Ding

    2014-04-01

    Different forms of heavy metals in soil will produce different environmental effects, and will directly influence the toxicity, migration and bioavailability of heavy metals. This study used lime, fly ash, dried sludge, peanut shells as stabilizers in the treatment of heavy metals in mineral waste residues. Morphological analyses of heavy metal, leaching experiments, potted plant experiments were carried out to analyze the migration and transformation of heavy metals. The results showed that after adding stabilizers, the pH of the acidic mineral waste residues increased to more than neutral, and the organic matter content increased significantly. The main existing forms of As, Pb, and Zn in the mineral waste residues were the residual. The contents of exchangeable and organic matter-bound As decreased by 65.6% and 87.7% respectively after adding fly ash, dried sludge and peanut shells. Adding lime, fly ash and peanut shells promoted the transformation of As from the Fe-Mn oxide-bound to the carbonate-bound, and adding lime and fly ash promoted the transformation of Pb and Zn from the exchangeable, Fe-Mn oxide-bound, organic matter-bound to the residual. After the early stage of the stabilization treatment, the contents of As, Pb and Zn in the leachate had varying degrees of decline, and adding peanut shells could reduce the contents of As, Pb and Zn in the leachate further. Among them, the content of As decreased most significantly after treatment with fly ash, dried sludge and peanut shells, with a decline of 57.4%. After treatment with lime, fly ash and peanut shells, the content of Zn decreased most significantly, by 24.9%. The addition of stabilizers was advantageous to the germination and growth of plants. The combination of fly ash, dried sludge and peanut shell produced the best effect, and the Vetiveria zizanioides germination rate reached 76% in the treated wasted mineral residues.

  12. Supporting Medical Home Transformation Through Evaluation of Patient Experience in a Large Culturally Diverse Primary Care Safety Net.

    PubMed

    Cook, Nicole; Hollar, T Lucas; Zunker, Christie; Peterson, Michael; Phillips, Teina; De Lucca, Michael

    2016-01-01

    The prevalence of chronic disease in the United States is rapidly increasing, with a disproportionate number of underserved, vulnerable patients sharing the burden. The Patient-Centered Medical Home (PCMH) is a care delivery model that has shown promise to improve primary care and address the burden of chronic illness. The purpose of this study was to (1) understand patient characteristics that might influence perceived patient experience in a large primary care safety net undergoing PCMH transformation; (2) identify community-level quality improvement opportunities to support ongoing transformation activities; and (3) establish a baseline of patient experience across the primary care safety net that could be used in repeated evaluations over the course of transformation. A cross-sectional study design was used to conduct this research. A total of 351 racially and ethnically diverse patients of 4 primary care safety net organizations in Broward County, Florida, were surveyed regarding their experience with access to care and coordination of care. Reported access to care and coordination of care. Patients with chronic disease who reported having visited the clinic 3 or more times in the past 12 months reported a better coordination of care experience than patients who had fewer than 3 visits in the past 12 months (odds ratio = 3.57; 95% confidence interval, 1.76-7.24). Patients without chronic disease who had been receiving care at the clinic for 2 or more years of care reported worse experience with access to care than patients with less than 2 years of care (odds ratio = 0.26; 95% confidence interval, 0.11-0.60.) Race, ethnicity, language, and education were not significant predictors of patient experience. Findings support ongoing efforts to improve patient engagement among all patients and to enhance resources to manage chronic disease, including community-based self-management programs, in primary care safety nets undergoing PCMH transformation.

  13. Reference Value Advisor: a new freeware set of macroinstructions to calculate reference intervals with Microsoft Excel.

    PubMed

    Geffré, Anne; Concordet, Didier; Braun, Jean-Pierre; Trumel, Catherine

    2011-03-01

    International recommendations for determination of reference intervals have been recently updated, especially for small reference sample groups, and use of the robust method and Box-Cox transformation is now recommended. Unfortunately, these methods are not included in most software programs used for data analysis by clinical laboratories. We have created a set of macroinstructions, named Reference Value Advisor, for use in Microsoft Excel to calculate reference limits applying different methods. For any series of data, Reference Value Advisor calculates reference limits (with 90% confidence intervals [CI]) using a nonparametric method when n≥40 and by parametric and robust methods from native and Box-Cox transformed values; tests normality of distributions using the Anderson-Darling test and outliers using Tukey and Dixon-Reed tests; displays the distribution of values in dot plots and histograms and constructs Q-Q plots for visual inspection of normality; and provides minimal guidelines in the form of comments based on international recommendations. The critical steps in determination of reference intervals are correct selection of as many reference individuals as possible and analysis of specimens in controlled preanalytical and analytical conditions. Computing tools cannot compensate for flaws in selection and size of the reference sample group and handling and analysis of samples. However, if those steps are performed properly, Reference Value Advisor, available as freeware at http://www.biostat.envt.fr/spip/spip.php?article63, permits rapid assessment and comparison of results calculated using different methods, including currently unavailable methods. This allows for selection of the most appropriate method, especially as the program provides the CI of limits. It should be useful in veterinary clinical pathology when only small reference sample groups are available. ©2011 American Society for Veterinary Clinical Pathology.

  14. Deletion of chromosome 9p21 noncoding cardiovascular risk interval in mice alters Smad2 signaling and promotes vascular aneurysm.

    PubMed

    Loinard, Céline; Basatemur, Gemma; Masters, Leanne; Baker, Lauren; Harrison, James; Figg, Nichola; Vilar, José; Sage, Andrew P; Mallat, Ziad

    2014-12-01

    Vascular aneurysm is an abnormal local dilatation of an artery that can lead to vessel rupture and sudden death. The only treatment involves surgical or endovascular repair or exclusion. There is currently no approved medical therapy for this condition. Recent data established a strong association between genetic variants in the 9p21 chromosomal region in humans and the presence of cardiovascular diseases, including aneurysms. However, the mechanisms linking this 9p21 DNA variant to cardiovascular risk are still unknown. Here, we show that deletion of the orthologous 70-kb noncoding interval on mouse chromosome 4 (chr4(Δ70kb/Δ70kb) mice) is associated with reduced aortic expression of cyclin-dependent kinase inhibitor genes p19Arf and p15Inkb. Vascular smooth muscle cells from chr4(Δ70kb/Δ70kb) mice show reduced transforming growth factor-β-dependent canonical Smad2 signaling but increased cyclin-dependent kinase-dependent Smad2 phosphorylation at linker sites, a phenotype previously associated with tumor growth and consistent with the mechanistic link between reduced canonical transforming growth factor-β signaling and susceptibility to vascular diseases. We also show that targeted deletion of the 9p21 risk interval promotes susceptibility to aneurysm development and rupture when mice are subjected to a validated model of aneurysm formation. The vascular disease of chr4(Δ70kb/Δ70kb) mice is prevented by treatment with a cyclin-dependent kinase inhibitor. The results establish a direct mechanistic link between 9p21 noncoding risk interval and susceptibility to aneurysm and may have important implications for the understanding and treatment of vascular diseases. © 2014 American Heart Association, Inc.

  15. Deformation, Fluid Flow and Mantle Serpentinization at Oceanic Transform Faults

    NASA Astrophysics Data System (ADS)

    Rupke, L.; Hasenclever, J.

    2017-12-01

    Oceanic transform faults (OTF) and fracture zones have long been hypothesized to be sites of enhanced fluid flow and biogeochemical exchange. In this context, the serpentine forming interaction between seawater and cold lithospheric mantle rocks is particularly interesting. The transformation of peridotite to serpentinite not only leads to hydration of oceanic plates and is thereby an important agent of the geological water cycle, it is also a mechanism of abiotic hydrogen and methane formation, which can support archeal and bacterial communities at the seafloor. Inferring the likely amount of mantle undergoing serpentinization reactions therefore allows estimating the amount of biomass that may be autotrophically produced at and around oceanic transform faults and mid-ocean ridges Here we present results of 3-D geodynamic model simulations that explore the interrelations between deformation, fluid flow, and mantle serpentinization at oceanic transform faults. We investigate how slip rate and fault offset affect the predicted patterns of mantle serpentinization around oceanic transform faults. Global rates of mantle serpentinization and associated H2 production are calculated by integrating the modeling results with plate boundary data. The global additional OTF-related production of H2 is found to be between 6.1 and 10.7 x 1011 mol per year, which is comparable to the predicted background mid-ocean ridge rate of 4.1 - 15.0 x 1011 mol H2/yr. This points to oceanic transform faults as potential sites of intense fluid-rock interaction, where chemosynthetic life could be sustained by serpentinization reactions.

  16. Polarity of recombination in transformation of Streptococcus pneumoniae

    PubMed Central

    Pasta, Franck; Sicard, Michel A.

    1999-01-01

    In transformation of Streptococcus pneumoniae DNA enters the cell as single-strand fragments and integrates into the chromosome by homologous recombination. Deletions and insertions of a few hundred base pairs frequently stop the recombination process of a donor strand. In this work we took advantage of such interruptions of recombination to compare the transformation efficiencies of the segments 5′- and 3′-ward from a deletion. The deletion was created in the center of a fragment of the ami locus, and sites around the deletion were labeled by a frameshift generating a restriction site. Heteroduplexes were constructed containing two restriction sites on one strand and two different ones on the complementary strand. ami+ bacteria were transformed with such heteroduplexes. ami− transformants were isolated and individually underwent amplification of the transformed ami region. We have obtained two kinds of amplification products: short when the deletion was integrated, long when recombination stops at the deletion. Each long fragment was tested by the four restriction enzymes to detect which strand and which side of the deletion had recombined. We found that 80% of the cuts were located 5′ to the deletion, showing that, in vivo, the 5′ side is strongly favored by recombination. Further results suggest that exchanges occurring from 5′ to 3′ relative to the donor strand are more efficient than in the opposite direction, thus accounting for the 5′ preference. PMID:10077616

  17. Polarity of recombination in transformation of Streptococcus pneumoniae.

    PubMed

    Pasta, F; Sicard, M A

    1999-03-16

    In transformation of Streptococcus pneumoniae DNA enters the cell as single-strand fragments and integrates into the chromosome by homologous recombination. Deletions and insertions of a few hundred base pairs frequently stop the recombination process of a donor strand. In this work we took advantage of such interruptions of recombination to compare the transformation efficiencies of the segments 5'- and 3'-ward from a deletion. The deletion was created in the center of a fragment of the ami locus, and sites around the deletion were labeled by a frameshift generating a restriction site. Heteroduplexes were constructed containing two restriction sites on one strand and two different ones on the complementary strand. ami+ bacteria were transformed with such heteroduplexes. ami- transformants were isolated and individually underwent amplification of the transformed ami region. We have obtained two kinds of amplification products: short when the deletion was integrated, long when recombination stops at the deletion. Each long fragment was tested by the four restriction enzymes to detect which strand and which side of the deletion had recombined. We found that 80% of the cuts were located 5' to the deletion, showing that, in vivo, the 5' side is strongly favored by recombination. Further results suggest that exchanges occurring from 5' to 3' relative to the donor strand are more efficient than in the opposite direction, thus accounting for the 5' preference.

  18. Improvements In Ball-Screw Linear Actuators

    NASA Technical Reports Server (NTRS)

    Iskenderian, Theodore; Joffe, Benjamin; Summers, Robert

    1996-01-01

    Report describes modifications of design of type of ball-screw linear actuator driven by dc motor, with linear-displacement feedback via linear variable-differential transformer (LVDT). Actuators used to position spacecraft engines to direct thrust. Modifications directed toward ensuring reliable and predictable operation during planned 12-year cruise and interval of hard use at end of cruise.

  19. The Winogradsky Column and Biofilms: Models for Teaching Nutrient Cycling and Succession in an Ecosystem.

    ERIC Educational Resources Information Center

    Anderson, Delia Castro; Hairston, Rosalina V.

    1999-01-01

    Presents protocols for setting up a Winogradsky column and biofilm slides, interpreting the chemical transformations that occur in the column as a result of color changes in the soil, identifying common microorganisms, and determining the microbial composition of the column over specified intervals of time. (WRM)

  20. Vlasov-Maxwell and Vlasov-Poisson equations as models of a one-dimensional electron plasma

    NASA Technical Reports Server (NTRS)

    Klimas, A. J.; Cooper, J.

    1983-01-01

    The Vlasov-Maxwell and Vlasov-Poisson systems of equations for a one-dimensional electron plasma are defined and discussed. A method for transforming a solution of one system which is periodic over a bounded or unbounded spatial interval to a similar solution of the other is constructed.

  1. Malignant transformation in chronic osteomyelitis: recognition and principles of management.

    PubMed

    Panteli, Michalis; Puttaswamaiah, Ravindra; Lowenberg, David W; Giannoudis, Peter V

    2014-09-01

    Malignant transformation as a result of chronic osteomyelitis represents a relatively rare and late complication with a declining incidence in the modern world. For most patients, the interval between the occurrence of the original bacterial infection and the transformation to malignant degeneration is several years. The diagnosis of malignant transformation in a chronic discharging sinus requires a high index of clinical suspicion. Wound biopsies should be obtained early, especially with the onset of new clinical signs such as increased pain, a foul smell, and changes in wound drainage. Squamous cell carcinoma is the most common presenting malignancy. Definitive treatment is amputation proximal to the tumor or wide local excision, combined with adjuvant chemotherapy and radiation therapy in selected patients. Early diagnosis may sometimes allow for treatment consisting of en bloc excision and limb salvage techniques. However, the most effective treatment is prevention with definitive treatment of the osteomyelitis, including adequate débridement, wide excision of the affected area, and early reconstruction. Copyright 2014 by the American Academy of Orthopaedic Surgeons.

  2. Low symptomatic premature stent occlusion of multiple plastic stents for benign biliary strictures: comparing standard and prolonged stent change intervals.

    PubMed

    Lawrence, Christopher; Romagnuolo, Joseph; Payne, K Mark; Hawes, Robert H; Cotton, Peter B

    2010-09-01

    Benign biliary strictures are typically managed endoscopically whereby an increasing size or number of plastic stents is placed at ERCP. Stents are often changed every 3 to 4 months based on the known median patency of a single biliary stent, but patency data for multiple biliary stents are lacking. To assess the incidence of occlusion-free survival of multiple plastic biliary stents and the rate of premature occlusion if left in longer than 6 months. Retrospective. Tertiary-care medical center (Charleston, SC). Consecutive patients who received multiple plastic stents for benign nonhilar biliary strictures from 1994 to 2008 were identified. Exchange of multiple plastic biliary stents within 6 months (group 1) or 6 months or longer (group 2) after placement. Symptomatic stent occlusion. Seventy-nine patients with nonhilar extrahepatic benign biliary stricture underwent 125 ERCPs with multiple plastic biliary stents. Stents were scheduled for removal/exchange within 6 months in 52 patients (86 ERCPs) compared with after 6 months in 22 patients (26 ERCPs). The median interval between multiple stent placement and removal/exchange was 90 days for group 1 and 242 days for group 2. Premature stent occlusion occurred in 4 of 52 (7.7%) patients in group 1 versus 1 of 22 (4.5%) in group 2, with significantly longer occlusion-free survival in group 2 (log-rank P < .0001). Retrospective study at a single tertiary referral center. Multiple plastic biliary stents for benign nonhilar strictures were associated with a low rate of premature symptomatic stent occlusion at more than 6 months and a longer occlusion-free survival. Copyright 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  3. Generator replacement is associated with an increased rate of ICD lead alerts.

    PubMed

    Lovelock, Joshua D; Cruz, Cesar; Hoskins, Michael H; Jones, Paul; El-Chami, Mikhael F; Lloyd, Michael S; Leon, Angel; DeLurgio, David B; Langberg, Jonathan J

    2014-10-01

    Lead malfunction is an important cause of morbidity and mortality in patients with an implantable cardioverter-defibrillator (ICD). We have shown that the failure of recalled high-voltage leads significantly increases after ICD generator replacement. However, generator replacement has not been recognized as a predictor of lead failure in general. The purpose of this study is to assess the effect of ICD generator exchange on the rate of ICD lead alerts. A time-dependent Cox proportional hazards model was used to analyze a database of remotely monitored ICDs. The model assessed the impact of generator exchange on the rate of lead alerts after ICD generator replacement. The analysis included 60,219 patients followed for 37 ± 19 months. The 5-year lead survival was 99.3% (95% confidence interval 99.2%-99.4%). Of 60,219 patients, 7458 patients (12.9%) underwent ICD generator exchange without lead replacement. After generator replacement, the rate of lead alerts was more than 5-fold higher than in controls with leads of the same age without generator replacement (hazard ratio 5.19; 95% confidence interval 3.45-7.84). A large number of lead alerted within 3 months of generator replacement. Lead alerts were more common in patients with single- vs dual-chamber ICDs and in younger patients. Sex was not associated with lead alerts. Routine generator replacement is associated with a 5-fold higher risk of lead alert compared to age-matched leads without generator replacement. This suggests the need for intense surveillance after generator replacement and the development of techniques to minimize the risk of lead damage during generator replacement. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  4. Estimating the costs of supporting safety-net transformation into patient-centered medical homes in post-Katrina New Orleans.

    PubMed

    Shao, Hui; Brown, Lisanne; Diana, Mark L; Schmidt, Laura A; Mason, Karen; Oronce, Carlos Irwin; Shi, Lizheng

    2016-09-01

    There is a need to understand the costs associated with supporting, implementing, and maintaining the system redesign of small and medium-sized safety-net clinics. The authors aimed to understand the characteristics of clinics that transformed into patient-centered medical homes and the incremental cost for transformation.The sample was 74 clinics in Greater New Orleans that received funds from the Primary Care Access and Stabilization Grant program between 2007 and 2010 to support their transformation. The study period was divided into baseline (September 21, 2007-March 21, 2008), transformation (March 22, 2008-March 21, 2009), and maintenance (March 22, 2009-September 20, 2010) periods, and data were collected at 6-month intervals. Baseline characteristics for the clinics that transformed were compared to those that did not. Fixed-effect models were conducted for cost estimation, controlling for baseline differences, using propensity score weights.Half of the 74 primary care clinics achieved transformation by the end of the study period. The clinics that transformed had higher total cost, more clinic visits, and a larger female patient proportion at baseline. The estimated incremental cost for clinics that underwent transformation was $37.61 per visit per 6 months, and overall it cost $24.86 per visit per 6 months in grant funds to support a clinic's transformation.Larger-sized clinics and those with a higher female proportion were more likely to transform. The Primary Care Access and Stabilization Grant program provided approximately $24.86 per visit over the 2 and 1/2 years. This estimated incremental cost could be used to guide policy recommendations to support primary care transformation in the United States.

  5. Estimating the costs of supporting safety-net transformation into patient-centered medical homes in post-Katrina New Orleans

    PubMed Central

    Shao, Hui; Brown, Lisanne; Diana, Mark L.; Schmidt, Laura A.; Mason, Karen; Oronce, Carlos Irwin; Shi, Lizheng

    2016-01-01

    Abstract There is a need to understand the costs associated with supporting, implementing, and maintaining the system redesign of small and medium-sized safety-net clinics. The authors aimed to understand the characteristics of clinics that transformed into patient-centered medical homes and the incremental cost for transformation. The sample was 74 clinics in Greater New Orleans that received funds from the Primary Care Access and Stabilization Grant program between 2007 and 2010 to support their transformation. The study period was divided into baseline (September 21, 2007–March 21, 2008), transformation (March 22, 2008–March 21, 2009), and maintenance (March 22, 2009–September 20, 2010) periods, and data were collected at 6-month intervals. Baseline characteristics for the clinics that transformed were compared to those that did not. Fixed-effect models were conducted for cost estimation, controlling for baseline differences, using propensity score weights. Half of the 74 primary care clinics achieved transformation by the end of the study period. The clinics that transformed had higher total cost, more clinic visits, and a larger female patient proportion at baseline. The estimated incremental cost for clinics that underwent transformation was $37.61 per visit per 6 months, and overall it cost $24.86 per visit per 6 months in grant funds to support a clinic's transformation. Larger-sized clinics and those with a higher female proportion were more likely to transform. The Primary Care Access and Stabilization Grant program provided approximately $24.86 per visit over the 2 and 1/2 years. This estimated incremental cost could be used to guide policy recommendations to support primary care transformation in the United States. PMID:27684855

  6. 75 FR 36140 - Self-Regulatory Organizations; NYSE Amex LLC; Notice of Filing of Proposed Rule Change Amending...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-24

    ... only on the Close and is subject to cancellation at any time before 3:45 p.m.\\5\\ \\3\\ See e-mail from... 4 p.m. The 10 minute interval is a legacy time frame related to the Exchange's prior publication of... obligations in the face of a dilemma that is unique to a physical Trading Floor, i.e., how to position...

  7. The Evolution of the Plasma Sheet Ion Composition: Storms and Recoveries: Plasma Sheet Ion Composition

    DOE PAGES

    Denton, M. H.; Thomsen, M. F.; Reeves, G. D.; ...

    2017-10-03

    The ion plasma sheet (~few hundred eV to ~few 10s keV) is usually dominated by H + ions. Here, changes in ion composition within the plasma sheet are explored both during individual events, and statistically during 54 calm-to-storm events and during 21 active-to-calm events. Ion composition data from the HOPE (Helium, Oxygen, Proton, Electron) instruments onboard Van Allen Probes satellites provide exceptional spatial and temporal resolution of the H +, O +, and He + ion fluxes in the plasma sheet. H+ shown to be the dominant ion in the plasma sheet in the calm-to-storm transition. However, the energy-flux ofmore » each ion changes in a quasi-linear manner during extended calm intervals. Heavy ions (O + and He +) become increasingly important during such periods as charge-exchange reactions result in faster loss for H + than for O + or He +. Results confirm previous investigations showing that the ion composition of the plasma sheet can be largely understood (and predicted) during calm intervals from knowledge of: (a) the composition of previously injected plasma at the onset of calm conditions, and (b) use of simple drift-physics models combined with calculations of charge-exchange losses.« less

  8. The Evolution of the Plasma Sheet Ion Composition: Storms and Recoveries: Plasma Sheet Ion Composition

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Denton, M. H.; Thomsen, M. F.; Reeves, G. D.

    The ion plasma sheet (~few hundred eV to ~few 10s keV) is usually dominated by H + ions. Here, changes in ion composition within the plasma sheet are explored both during individual events, and statistically during 54 calm-to-storm events and during 21 active-to-calm events. Ion composition data from the HOPE (Helium, Oxygen, Proton, Electron) instruments onboard Van Allen Probes satellites provide exceptional spatial and temporal resolution of the H +, O +, and He + ion fluxes in the plasma sheet. H+ shown to be the dominant ion in the plasma sheet in the calm-to-storm transition. However, the energy-flux ofmore » each ion changes in a quasi-linear manner during extended calm intervals. Heavy ions (O + and He +) become increasingly important during such periods as charge-exchange reactions result in faster loss for H + than for O + or He +. Results confirm previous investigations showing that the ion composition of the plasma sheet can be largely understood (and predicted) during calm intervals from knowledge of: (a) the composition of previously injected plasma at the onset of calm conditions, and (b) use of simple drift-physics models combined with calculations of charge-exchange losses.« less

  9. Simplified estimation of age-specific reference intervals for skewed data.

    PubMed

    Wright, E M; Royston, P

    1997-12-30

    Age-specific reference intervals are commonly used in medical screening and clinical practice, where interest lies in the detection of extreme values. Many different statistical approaches have been published on this topic. The advantages of a parametric method are that they necessarily produce smooth centile curves, the entire density is estimated and an explicit formula is available for the centiles. The method proposed here is a simplified version of a recent approach proposed by Royston and Wright. Basic transformations of the data and multiple regression techniques are combined to model the mean, standard deviation and skewness. Using these simple tools, which are implemented in almost all statistical computer packages, age-specific reference intervals may be obtained. The scope of the method is illustrated by fitting models to several real data sets and assessing each model using goodness-of-fit techniques.

  10. Anion-induced structural transformation of a sulfate-incorporated 2D Cd(II)–organic framework

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Li-Wei; Institute of Materials Science and Engineering, National Central University, Taoyuan 320, Taiwan; Luo, Tzuoo-Tsair

    2016-07-15

    A Cd(II)–organic framework {[Cd_2(tpim)_4(SO_4)(H_2O)_2]·(SO_4)·21H_2O}{sub n} (1) was synthesized by reacting CdSO{sub 4}·8/3H{sub 2}O and 2,4,5-tri(4-pyridyl)imidazole (tpim) under hydrothermal conditions. A structural analysis showed that compound 1 adopts a layered structure in which the [Cd(tpim){sub 2}]{sub n} chains are linked by sulfate anions. These 2D layers are further packed into a 3D supramolecular framework via π–π interactions. The structure contains two types of SO{sub 4}{sup 2−} anions, i.e., bridging SO{sub 4}{sup 2−} and free SO{sub 4}{sup 2−} anions, the latter of which are included in the large channels of the framework. Compound 1 exhibits interesting anion exchange behavior. In the presencemore » of SCN{sup −} anions, both the bridging and free SO{sub 4}{sup 2−} anions in 1 were completely exchanged by SCN{sup −} ligands to form a 1D species [Cd(tpim){sub 2}(SCN){sub 2}] (1A), in which the SCN{sup –} moieties function as a monodentate ligand. On the other hand, when compound 1 was ion exchanged with N{sub 3}{sup −} anions in aqueous solution, the bridging SO{sub 4}{sup 2−} moieties remained intact, and only the free guest SO{sub 4}{sup 2−} were replaced by N{sub 3}{sup −} anions. The gas adsorption behavior of the activated compound 1 was also investigated. - Highlights: • An interesting anion-induced structural transformation of a sulfate-incorporated 2D Cd(II)–organic framework is reported. • The sulfate-incorporated 2D layer compound exhibits very different anion exchange behavior with respect to SCN{sup −} and N{sub 3}{sup −}. • Both the bridging and free SO{sub 4}{sup 2−} anions in the 2D structure were completely exchanged by SCN{sup −} ligands, resulting in the formation of a 1D species. However, in the case of N{sub 3}{sup −} anions, only the free guest SO{sub 4}{sup 2−} in the structure was replaced.« less

  11. Analysis of free turbulent shear flows by numerical methods

    NASA Technical Reports Server (NTRS)

    Korst, H. H.; Chow, W. L.; Hurt, R. F.; White, R. A.; Addy, A. L.

    1973-01-01

    Studies are described in which the effort was essentially directed to classes of problems where the phenomenologically interpreted effective transport coefficients could be absorbed by, and subsequently extracted from (by comparison with experimental data), appropriate coordinate transformations. The transformed system of differential equations could then be solved without further specifications or assumptions by numerical integration procedures. An attempt was made to delineate different regimes for which specific eddy viscosity models could be formulated. In particular, this would account for the carryover of turbulence from attached boundary layers, the transitory adjustment, and the asymptotic behavior of initially disturbed mixing regions. Such models were subsequently used in seeking solutions for the prescribed two-dimensional test cases, yielding a better insight into overall aspects of the exchange mechanisms.

  12. Travel as a Transformational Spiritual Event.

    PubMed

    Prater, Lyn S; Riley, Cheryl; Garner, Shelby L; Spies, Lori A

    2016-11-01

    There is a philosophical connection between elements of travel and elements of spirituality. Nurses can develop spiritual intelligence, hone transcultural skills, and develop cultural humility through travel. Concepts of spiritual intelligence are incorporated to distinguish spirituality from religion. This discussion is to describe the spiritual attributes of travel through exploration of unique cultural sameness and differences, stepping out of one's routine, experiences of solitude, and the application to nursing. Venues such as study abroad, mission trips, cultural exchange opportunities, and service learning projects all can provide meaningful times of transformation, spiritual growth, learning new ways of doing things, and of being in the world. Nurses who integrate these practices into the care they provide daily will be enriched personally and rewarded with improved outcomes. © The Author(s) 2015.

  13. Harnessing Thin-Film Continuous-Flow Assembly Lines.

    PubMed

    Britton, Joshua; Castle, Jared W; Weiss, Gregory A; Raston, Colin L

    2016-07-25

    Inspired by nature's ability to construct complex molecules through sequential synthetic transformations, an assembly line synthesis of α-aminophosphonates has been developed. In this approach, simple starting materials are continuously fed through a thin-film reactor where the intermediates accrue molecular complexity as they progress through the flow system. Flow chemistry allows rapid multistep transformations to occur via reaction compartmentalization, an approach not amenable to using conventional flasks. Thin film processing can also access facile in situ solvent exchange to drive reaction efficiency, and through this method, α-aminophosphonate synthesis requires only 443 s residence time to produce 3.22 g h(-1) . Assembly-line synthesis allows unprecedented reaction flexibility and processing efficiency. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Synthesis of model humic substances: a mechanistic study using controllable H/D exchange and Fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Zherebker, Alexander Ya; Airapetyan, David; Konstantinov, Andrey I; Kostyukevich, Yury I; Kononikhin, Alexey S; Popov, Igor A; Zaitsev, Kirill V; Nikolaev, Eugene N; Perminova, Irina V

    2015-07-07

    The products of the oxidative coupling of phenols are frequently used as synthetic analogues to natural humic substances (HS) for biomedical research. However, their molecular compositions and exact structures remain largely unknown. The objective of this study was to develop a novel approach for the molecular-level analysis of phenolic polymerisates that is capable of inventorying molecular constituents and resolving their distinct structural formulas. For this purpose, we have synthesized the model HS using the oxidative coupling of a specifically designed phenylpropanoic monomer, 3-(4-hydroxy-3-methoxyphenyl)-3-oxopropionic acid, to hydroquinone. We have characterized the synthesized model HS using high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS), (1)H NMR spectroscopy, and controllable hydrogen/deuterium (H/D) exchange. We succeeded in the molecular inventory of the model HS. The assigned molecular formulas occupied the substantial space of CHO compositions in the Van Krevelen diagram with a maximum density found in the regions of tannins and lignins, resembling those of natural HS. To identify the exact structural formulas of the individual constituents in the model HS, we have applied selective H/D exchange of non-labile backbone protons by a choice of basic or acidic catalytic conditions followed by FTICR MS. The determined formulas allowed us to verify the proposed pathways of hydroxylation and carboxylation in the course of the phenolic coupling and to identify the acetylation of aromatic rings as an important side reaction. We conclude that the proposed analytical approach may be used to identify the molecular carriers of biological activity within the phenolic polymerisates and eventually within natural HS.

  15. Kinetics of methane-ethane gas replacement in clathrate-hydrates studied by time-resolved neutron diffraction and Raman spectroscopy.

    PubMed

    Murshed, M Mangir; Schmidt, Burkhard C; Kuhs, Werner F

    2010-01-14

    The kinetics of CH(4)-C(2)H(6) replacement in gas hydrates has been studied by in situ neutron diffraction and Raman spectroscopy. Deuterated ethane structure type I (C(2)H(6) sI) hydrates were transformed in a closed volume into methane-ethane mixed structure type II (CH(4)-C(2)H(6) sII) hydrates at 5 MPa and various temperatures in the vicinity of 0 degrees C while followed by time-resolved neutron powder diffraction on D20 at ILL, Grenoble. The role of available surface area of the sI starting material on the formation kinetics of sII hydrates was studied. Ex situ Raman spectroscopic investigations were carried out to crosscheck the gas composition and the distribution of the gas species over the cages as a function of structure type and compared to the in situ neutron results. Raman micromapping on single hydrate grains showed compositional and structural gradients between the surface and core of the transformed hydrates. Moreover, the observed methane-ethane ratio is very far from the one expected for a formation from a constantly equilibrated gas phase. The results also prove that gas replacement in CH(4)-C(2)H(6) hydrates is a regrowth process involving the nucleation of new crystallites commencing at the surface of the parent C(2)H(6) sI hydrate with a progressively shrinking core of unreacted material. The time-resolved neutron diffraction results clearly indicate an increasing diffusion limitation of the exchange process. This diffusion limitation leads to a progressive slowing down of the exchange reaction and is likely to be responsible for the incomplete exchange of the gases.

  16. Decreasing the Thermal Load on the Environment with the Help of Thermal Pumps in the Sewage Treatment System

    NASA Astrophysics Data System (ADS)

    Lozovetskii, V. V.; Lebedev, V. V.; Cherkina, V. M.; Ivanchuk, M. S.

    2018-05-01

    We propose designs for practical use of residual heat of sewage by means of thermal-pump transformation of thermal energy in plants operating on inverse Rankine and Lorentz cycles, as well as a method for sewage heat removal in drainage canals of water removal systems based on the application of double-pipe heat exchangers known as Field tubes.

  17. Genetic Manipulation of Streptococcus pyogenes (The Group A Streptococcus, GAS)

    PubMed Central

    Le Breton, Yoann; McIver, Kevin S.

    2013-01-01

    Streptococcus pyogenes (the group A streptococcus, GAS) is a Gram-positive bacterium responsible for a wide spectrum of diseases ranging from mild superficial infections (pharyngitis, impetigo) to severe often life-threatening invasive diseases (necrotizing fasciitis, streptococcal toxic shock syndrome) in humans. This unit describes molecular techniques for the genetic manipulation of S. pyogenes with detailed protocols for transformation, gene disruption, allelic exchange, transposon mutagenesis, and genetic complementation. PMID:24510894

  18. Transformative Colloidal Nanomaterials for Mid- Infrared Devices

    DTIC Science & Technology

    2015-06-11

    like. Luminescence has been detected up to the detection limit of our MCT detector (11 microns). Inorganic ligand exchange using ammonium sulfide...biexciton lifetime is not changing significantly, being about 30-50 ps. One issue with CQDs films for mid-IR detection will be to achieve noise ...limited by generation/recombination. Our first studies showed that at 1kHz, 1/f noise dominated starting at temperatures of 100K and increased

  19. Decreasing the Thermal Load on the Environment with the Help of Thermal Pumps in the Sewage Treatment System

    NASA Astrophysics Data System (ADS)

    Lozovetskii, V. V.; Lebedev, V. V.; Cherkina, V. M.; Ivanchuk, M. S.

    2018-03-01

    We propose designs for practical use of residual heat of sewage by means of thermal-pump transformation of thermal energy in plants operating on inverse Rankine and Lorentz cycles, as well as a method for sewage heat removal in drainage canals of water removal systems based on the application of double-pipe heat exchangers known as Field tubes.

  20. Cu(ii)-catalyzed sulfide construction: both aryl groups utilization of intermolecular and intramolecular diaryliodonium salt.

    PubMed

    Wang, Ming; Wei, Jianpeng; Fan, Qiaoling; Jiang, Xuefeng

    2017-03-07

    A sulfur-iodine exchange protocol of diaryliodonium salts with inorganic sulfur salt was developed. Both aryl groups in the diaryliodonium salt were fully exerted in this transformation. Five- to eight-membered sulfur-containing heterocycles were achieved. Note that [1]benzothieno-[3,2-b][1]benzothiophene (BTBT) (an organic field-effect transistor (OFET) material) and Zaltoprofen were efficiently established through this method.

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