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Sample records for helje kaarma sde

  1. Flight dynamics system software development environment (FDS/SDE) tutorial

    NASA Technical Reports Server (NTRS)

    Buell, John; Myers, Philip

    1986-01-01

    A sample development scenario using the Flight Dynamics System Software Development Environment (FDS/SDE) is presented. The SDE uses a menu-driven, fill-in-the-blanks format that provides online help at all steps, thus eliminating lengthy training and allowing immediate use of this new software development tool.

  2. BASELINE MEMBRANE SELECTION AND CHARACTERIZATION FOR AN SDE

    SciTech Connect

    Colon-Mercado, H; David Hobbs, D

    2007-04-03

    Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. In FY05 and FY06, testing at the Savannah River National Laboratory (SRNL) explored a low temperature fuel cell design concept for the SDE. The advantages of this design concept include high electrochemical efficiency and small footprint that are crucial for successful implementation on a commercial scale. A key component of the SDE is the ion conductive membrane through which protons produced at anode migrate to the cathode and react to produce hydrogen. An ideal membrane for the SDE should have both low ionic resistivity and low sulfur dioxide transport. These features allow the electrolyzer to perform at high currents with low potentials, along with preventing contamination of both the hydrogen output and poisoning of the catalysts involved. Another key component is the electrocatalyst material used for the anode and cathode. Good electrocatalysts should be chemically stable and have a low overpotential for the desired electrochemical reactions. This report summarizes results from activities to evaluate commercial and experimental membranes for the SDE. Several different types of commercially-available membranes were analyzed for sulfur dioxide transport as a function of acid strength including perfluorinated sulfonic acid (PFSA), sulfonated poly-etherketone-ketone, and poly-benzimidazole (PBI) membranes. Experimental membranes from the sulfonated diels-alder polyphenylenes (SDAPP) and modified Nafion{reg_sign} 117 were evaluated for SO{sub 2} transport as well. These membranes exhibited reduced transport coefficient for SO{sub 2} transport without the loss in ionic conductivity. The use of Nafion{reg_sign} with EW 1100 is recommended for the present SDE testing due to the limited data regarding chemical

  3. ENISI SDE: A New Web-Based Tool for Modeling Stochastic Processes.

    PubMed

    Mei, Yongguo; Carbo, Adria; Hoops, Stefan; Hontecillas, Raquel; Bassaganya-Riera, Josep

    2015-01-01

    Modeling and simulations approaches have been widely used in computational biology, mathematics, bioinformatics and engineering to represent complex existing knowledge and to effectively generate novel hypotheses. While deterministic modeling strategies are widely used in computational biology, stochastic modeling techniques are not as popular due to a lack of user-friendly tools. This paper presents ENISI SDE, a novel web-based modeling tool with stochastic differential equations. ENISI SDE provides user-friendly web user interfaces to facilitate adoption by immunologists and computational biologists. This work provides three major contributions: (1) discussion of SDE as a generic approach for stochastic modeling in computational biology; (2) development of ENISI SDE, a web-based user-friendly SDE modeling tool that highly resembles regular ODE-based modeling; (3) applying ENISI SDE modeling tool through a use case for studying stochastic sources of cell heterogeneity in the context of CD4+ T cell differentiation. The CD4+ T cell differential ODE model has been published [8] and can be downloaded from biomodels.net. The case study reproduces a biological phenomenon that is not captured by the previously published ODE model and shows the effectiveness of SDE as a stochastic modeling approach in biology in general and immunology in particular and the power of ENISI SDE.

  4. PCNA-Dependent Cleavage and Degradation of SDE2 Regulates Response to Replication Stress

    PubMed Central

    Jo, Ukhyun; Cai, Winson; Wang, Jingming; Kwon, Yoojin; D’Andrea, Alan D.

    2016-01-01

    Maintaining genomic integrity during DNA replication is essential for cellular survival and for preventing tumorigenesis. Proliferating cell nuclear antigen (PCNA) functions as a processivity factor for DNA replication, and posttranslational modification of PCNA plays a key role in coordinating DNA repair against replication-blocking lesions by providing a platform to recruit factors required for DNA repair and cell cycle control. Here, we identify human SDE2 as a new genome surveillance factor regulated by PCNA interaction. SDE2 contains an N-terminal ubiquitin-like (UBL) fold, which is cleaved at a diglycine motif via a PCNA-interacting peptide (PIP) box and deubiquitinating enzyme activity. The cleaved SDE2 is required for negatively regulating ultraviolet damage-inducible PCNA monoubiquitination and counteracting replication stress. The cleaved SDE2 products need to be degraded by the CRL4CDT2 ubiquitin E3 ligase in a cell cycle- and DNA damage-dependent manner, and failure to degrade SDE2 impairs S phase progression and cellular survival. Collectively, this study uncovers a new role for CRL4CDT2 in protecting genomic integrity against replication stress via regulated proteolysis of PCNA-associated SDE2 and provides insights into how an integrated UBL domain within linear polypeptide sequence controls protein stability and function. PMID:27906959

  5. SDE and SPME Analysis of Flavor Compounds in Jin Xuan Oolong Tea.

    PubMed

    Sheibani, Ershad; Duncan, Susan E; Kuhn, David D; Dietrich, Andrea M; O'Keefe, Sean F

    2016-02-01

    Simultaneous distillation-extraction (SDE) and solid phase micro extraction (SPME) are procedures used for the isolation of flavor compounds in foods. The purpose of this study was to optimize SDE conditions (solvent and time) and to compare SDE with SPME for the isolation of flavor compounds in Jin Xuan oolong tea using GC-MS and GC-O. The concentration of volatile compounds isolated with diethyl ether was higher (P < 0.05) than for dichloromethane and concentration was higher at 40 min (P < 0.05) than 20 or 60 min extractions. For SDE, 128 volatiles were identified using GC-MS and 45 aroma active compounds using GC-O. Trans-nerolidol was the most abundant compound in oolong tea. The number of volatiles identified using GC-MS was lower in SPME than SDE. For SPME, 59 volatiles and 41 aroma active compounds were identified. The composition of the volatiles isolated by the 2 methods differed considerably but provided complementary information.

  6. Identification of volatile components in yak butter using SAFE, SDE and HS-SPME-GC/MS.

    PubMed

    Li, Ning; Sun, Bao-Guo; Zheng, Fu-Ping; Chen, Hai-Tao; Liu, Si-Yuan; Gu, Chen; Song, Zhen-Yang

    2012-01-01

    The volatile components of yak butter were isolated by solvent-assisted flavour evaporation (SAFE), simultaneous distillation extraction (SDE; dichloromethane and diethyl ether as solvent, respectively) and headspace solid-phase microextraction (HS-SPME; CAR/PDMS, PDMS/DVB and DVB/CAR/PDMS fibre extraction, respectively) and were analysed by GC/MS. A total of 83 volatile components were identified under six different conditions, including 28 acids, 12 esters, 11 ketones, 10 lactones, 10 alcohols, 4 other compounds, 2 aldehydes, 2 unsaturated aldehydes, 1 furan, 1 sulphur-containing compound, 1 unsaturated alcohol and 1 unsatruated ketone. Among them, 51 were identified by SAFE, 58 by SDE (45 with dichloromethane as solvent and 41 with diethyl ether as solvent) and 40 by HS-SPME (26 with CAR/PDMS; 26 with PDMS/DVB and 32 with DVB/CAR/PDMS). Three pretreatment methods were compared to show that the volatile components obtained using different methods varied greatly, both in terms of categories and in content. Therefore, a multi-pretreatment method should be adopted, together with GC/MS. A total of 25 aroma-active compounds were detected by gas chromatography-olfactometry, among which 20 aroma-active compounds were found by SDE (14 with dichloromethane as solvent and 14 with diethyl ether as solvent) and 17 by SAFE.

  7. The self-disproportionation of the enantiomers (SDE) of methyl n-pentyl sulfoxide via achiral, gravity-driven column chromatography: a case study.

    PubMed

    Wzorek, Alicja; Klika, Karel D; Drabowicz, Józef; Sato, Azusa; Aceña, José Luis; Soloshonok, Vadim A

    2014-07-14

    This work explores the self-disproportionation of enantiomers (SDE) of chiral sulfoxides via achiral, gravity-driven column chromatography using methyl n-pentyl sulfoxide as a case study. A major finding of this work is the remarkable persistence and high magnitude of the SDE for the analyte. Thus, it is the first case where SDE is observed even in the presence of MeOH in the mobile phase. The study demonstrated the practical preparation, in line with theory, of enantiomerically pure (>99.9% ee) samples of methyl n-pentyl sulfoxide starting from a sample of only modest ee (<35%). Remarkably, it was found that the order of elution was inverted, i.e. enantiomerically depleted fractions preceded later eluting enantiomerically enriched ones, when the stationary phase was changed from silica gel to aluminum oxide. To the best of our knowledge, this is the first occurrence of inverted SDE behavior due solely to a change in the stationary phase. Aberrant SDE behavior was observed in that the ee did not always fall continuously during the progression of the chromatography, and this was attributed to the complexity of the system at hand which cannot be described in simple terms such as the formation only of homo- and heterochiral dimers based on a single interaction. The results nevertheless suggest that all compounds with a chiral sulfoxide moiety in their structure are likely to exhibit the SDE phenomenon and thus this work constitutes the first example of SDE predictability. Moreover, it could well be that optical purification based on the SDE phenomenon is a simple, convenient, and inexpensive method for the optical purification of this class of compounds with a high degree of proficiency.

  8. The effects of magnetic field modifications on the solar modulation of cosmic rays with a SDE-based model

    NASA Astrophysics Data System (ADS)

    Raath, Jan-Louis; Toit Strauss, Du; Kopp, Andreas; Potgieter, Marius

    2016-07-01

    The effects of modifying the heliospheric magnetic field, particularly in the polar regions of the heliosphere, are illustrated by utilizing a numerical model based on the solution of a set of stochastic differential equations (SDEs). Because SDE-based models are especially well suited for such studies, we are able to gain new insights into this subject. The differences in the modulation brought about by each of three choices for the heliospheric magnetic field are studied as typical well-known cases; they are the unmodified Parker field, and the Smith-Bieber and Jokipii-Kóta modified fields. It is illustrated that both these modifications change the Parker field satisfactorily in the heliospheric polar regions, but that the modification of Smith and Bieber affects a larger reduction in cosmic ray drift effects in these regions. The general features of these two modifications are illustrated and the Smith-Bieber modified field is applied in a cosmic ray modulation model to reproduce observational proton spectra from the PAMELA mission during the solar minimum of 2006 - 2009. These SDE-based results are compared to the results from other studies and found to be in good qualitative agreement.

  9. Identification of volatile components in Chinese Sinkiang fermented camel milk using SAFE, SDE, and HS-SPME-GC/MS.

    PubMed

    Ning, Li; Fu-Ping, Zheng; Hai-Tao, Chen; Si-Yuan, Liu; Chen, Gu; Zhen-Yang, Song; Bao-Guo, Sun

    2011-12-01

    The volatile components of Chinese Sinkiang fermented camel milk were isolated by solvent assisted flavour evaporation (SAFE), simultaneous distillation extraction (SDE, dichloromethane and diethyl ether as solvent, respectively) and headspace solid-phase microextraction (HS-SPME, CAR/PDMS, PDMS/DVB and DVB/CAR/PDMS fibre extraction, respectively) and analysed by GC/MS. A total of 133 volatile components were identified under 6 different conditions, including 30 esters, 20 acids, 18 saturated alcohols, 15 unsaturated aliphatic alcohols, 8 saturated ketones, 9 saturated aldehydes, 8 unsaturated aliphatic aldehydes, 6 furans, 5 sulphur-containing compounds, 5 ethers, 5 lactones, 3 other compounds, and 1 unsaturated aliphatic ketone. Three pretreatment methods were compared, assisted by principal component analysis (PCA). The results indicated that the volatile components obtained using different methods varied greatly both in categories and in content, and therefore, a multi-pretreatment method should be adopted together with GC/MS. A total of 71 aroma-active compounds were detected by gas chromatography-olfactometry (GC-O), among which 66 aroma-active compounds were found by SDE (60, dichloromethane as solvent; 24, diethyl ether as solvent), 26 by SAFE.

  10. The effects of magnetic field modifications on the solar modulation of cosmic rays with a SDE-based model

    NASA Astrophysics Data System (ADS)

    Raath, J. L.; Potgieter, M. S.; Strauss, R. D.; Kopp, A.

    2016-05-01

    A numerical model for the solar modulation of cosmic rays, based on the solution of a set of stochastic differential equations (SDEs), is used to illustrate the effects of modifying the heliospheric magnetic field, particularly in the polar regions of the heliosphere. SDE-based models are well suited for such studies so that new insights are gained. To this end, the differences in the modulation brought about by each of three choices for the heliospheric magnetic field, i.e. the unmodified Parker field, the Smith-Bieber modified field, and the Jokipii-Kóta modified field, are studied as typical well-known cases. It is illustrated that although both these modifications change the Parker field satisfactorily in the polar regions of the heliosphere, the Smith-Bieber modification is more effective in reducing cosmic ray drift effects in these regions. The features of these two modifications, as well as the effects on the solar modulation of cosmic rays, are illustrated qualitatively and quantitatively. In particular, it is shown how the Smith-Bieber modified field is applied in a cosmic ray modulation model to reproduce observational proton spectra from the PAMELA mission during the solar minimum of 2006-2009. These SDE-based results are compared with those obtained in previous studies of this unusual solar minimum activity period and found to be in good qualitative agreement.

  11. Characterization of Aronia melanocarpa volatiles by headspace-solid-phase microextraction (HS-SPME), simultaneous distillation/extraction (SDE), and gas chromatography-olfactometry (GC-O) methods.

    PubMed

    Kraujalytė, Vilma; Leitner, Erich; Venskutonis, Petras Rimantas

    2013-05-22

    The profiles of volatile constituents of berry fruit of two Aronia melanocarpa genotypes were evaluated by headspace-solid-phase microextraction (HS-SPME), simultaneous distillation and extraction (SDE), and gas chromatography-olfactometry (GC-O). In total, 74 volatile compounds were identified in chokeberry juice, 3-penten-2-one, 3,9-epoxy-p-menth-1-ene, and benzaldehyde being the most abundant constituents; however, their percentage concentrations were remarkably different in the HS-SPME and SDE profiles. Twenty two aroma-active compounds were detected and characterized by the trained panelists in HS-SPME using GC-O detection frequency analysis. Olfactometry revealed that ethyl-2-methyl butanoate, ethyl-3-methyl butanoate, ethyl decanoate ("fruity" aroma notes), nonanal ("green" notes), unidentified compound possessing "moldy" odor, and some other volatiles may be very important constituents in formation of chokeberry aroma of both analyzed plant cultivars.

  12. CRADA Final Report For CRADA NO. CR-12-006 [Operation and Testing of an SO{sub 2}-depolarized Electrolyzer (SDE) for the Purpose of Hydrogen and Sulfuric Acid Production

    SciTech Connect

    Summers, W. A.; Colon-Mercado, H. R.; Steimke, J. L.; Zahn, Steffen

    2014-02-24

    Over the past several years, Savannah River National Laboratory (SRNL) has led a team of collaborators under the Department of Energy’s (DOE) nuclear hydrogen production program to develop the Hybrid Sulfur (HyS) Process. HyS is a 2-step water-splitting process consisting of high temperature decomposition of sulfuric acid to generate SO{sub 2}, followed by the electrolysis of aqueous SO{sub 2} to generate hydrogen and sulfuric acid. The latter is fed back into the high temperature reactor. SRNL designed and built an SO{sub 2}-depolarized electrolyzer (SDE) and a test facility. Over 40 SDE’s were tested using different catalysts, membranes and other components. SRNL demonstrated that an SDE could be operated continuously for approximately 200 hours under certain conditions without buildup of sulfur at the SDE’s cathode, thus solving a key technical problem with SDE technology. Air Products and Chemicals, Inc. (APCI) is a major supplier of hydrogen production systems, and they have proprietary technology that could benefit from the SDE developed by SRNS, or some improved version thereof. However, to demonstrate that SRNL’s SDE is a truly viable approach to the electrolyzer design, continuous operation for far greater periods of time than 200 hours must be demonstrated, and the electrolyzer must be scaled up to greater hydrogen production capacities. SRNL and Air Products entered into a Cooperative Research and Development Agreement with the objective of demonstrating the effectiveness of the SDE for hydrogen and sulfuric acid production and to demonstrate long-term continuous operation so as to dramatically increase the confidence in the SDE design for commercial operation. SRNL prepared a detailed technical report documenting previous SDE development, including the current SDE design and operating conditions that led to the 200-hour sulfurfree testing. SRNL refurbished its single cell SDE test facility and qualified the equipment for continuous operation. A

  13. Remarkable magnitude of the self-disproportionation of enantiomers (SDE) via achiral chromatography: application to the practical-scale enantiopurification of β-amino acid esters.

    PubMed

    Wzorek, Alicja; Sato, Azusa; Drabowicz, Józef; Soloshonok, Vadim A; Klika, Karel D

    2016-02-01

    We report the best performance yet for the self-disproportionation of enantiomers (SDE) via achiral chromatography as typically used in laboratories for the isolated yield of the excess enantiomer using N-acetyl β-amino acid ethyl esters. The results are the most convincing ever demonstration of the capability of the SDE for practical-scale enantiopurification as comparable, or even superior for some systems, to that of recrystallization. For example, from a sample of 94.4 % ee, a yield of 71 % of enantiopure material was isolated in a single chromatographic run. Moreover, the lack of an esoteric structural entity, e.g. strongly polarizing groups, such as, for instance CF3, highlights the fact that the phenomenon is not dependent on the presence of such and thus the process is relevant to any usual-type structure. In contrast to recrystallization, the procedure is predictable, general, and dependable, boding well for its widespread application in routine laboratory settings.

  14. Ten-year study of fine aerosol at Sde Boker, Israel, using PIXE: Time trends, seasonal variation, correlations, and source areas for anthropogenic elements

    NASA Astrophysics Data System (ADS)

    Maenhaut, Willy; Karnieli, Arnon; Andreae, Meinrat O.

    2014-01-01

    From January 1995 through December 2004 aerosol samples were collected at Sde Boker, Israel, with a Gent stacked filter unit sampler. The collections were done according to a 2-2-3 day schedule, which resulted in about 150 samples per year. The samples were analysed for the particulate mass (PM) by weighing, for black carbon (BC) by a light reflectance technique, and for up to 46 elements by a combination of PIXE and instrumental neutron activation analysis. Here, we report on the fine (PM2) size fraction data for the PM, BC, and the following nine anthropogenic elements S, V, Ni, Cu, Zn, As, Se, Sb, and Pb, and discuss their time trends, seasonal variation, correlations, and source areas. The largest changes in the annual medians over the 10-year period were found for S, Ni, Se, Sb, and Pb, i.e., of -34%, -25%, -47%, +26%, and -40%, respectively. The seasonal variation was largest for S, with 1.6 times higher concentrations in summer than in the other three seasons. Vanadium and Ni were very highly correlated with each other (r = 0.95), pointing to a dominant common source, which is undoubtedly oil burning. Trajectory statistics, using 10-day back trajectories with arrival at 300 m above ground, were applied to assess the source areas. Sulphur originated mostly from south-eastern Europe (i.e., Turkey, Bulgaria, Romania, Ukraine, and southern Russia) and As from the south-eastern part of European Russia, whilst the source picture for Zn was rather unclear. The other six anthropogenic elements and BC seemed to originate mainly from regional sources.

  15. ODE, RDE and SDE Models of Cell Cycle Dynamics and Clustering in Yeast

    PubMed Central

    Boczko, Erik M.; Stowers, Chris C.; Gedeon, Tomas; Young, Todd R.

    2009-01-01

    Biologists have long observed periodic-like oxygen consumption oscillations in yeast populations under certain conditions and several unsatisfactory explanations for this phenomenon have been proposed. These “autonomous oscillations” have often appeared with periods that are nearly integer divisors of the calculated doubling time of the culture. We hypothesize that these oscillations could be caused by a form of cell cycle synchronization that we call clustering. We develop some novel ordinary differential equation models of the cell cycle. For these models, and for random and stochastic perturbations, we give both rigorous proofs and simulations showing that both positive and negative growth rate feedback within the cell cycle are possible agents that can cause clustering of populations within the cell cycle. It occurs for a variety of models and for a broad selection of parameter values. These results suggest that the clustering phenomenon is robust and is likely to be observed in nature. Since there are necessarily an integer number of clusters, clustering would lead to periodic-like behavior with periods that are nearly integer divisors of the period of the cell cycle. Related experiments have shown conclusively that cell cycle clustering occurs in some oscillating yeast cultures. PMID:20563236

  16. The ArcSDE GIS Dynamic Population Model Tool for Savannah River Site Emergency Response

    SciTech Connect

    MCLANE, TRACY; JONES, DWIGHT

    2005-10-03

    The Savannah River Site (SRS) is a 310-square-mile Department of Energy site located near Aiken, South Carolina. With a workforce of over 10,000 employees and subcontractors, SRS emergency personnel must be able to respond to an emergency event in a timely and effective manner, in order to ensure the safety and security of the Site. Geographic Information Systems (GIS) provides the technology needed to give managers and emergency personnel the information they need to make quick and effective decisions. In the event of a site evacuation, knowing the number of on-site personnel to evacuate from a given area is an essential piece of information for emergency staff. SRS has developed a GIS Dynamic Population Model Tool to quickly communicate real-time information that summarizes employee populations by facility area and building and then generates dynamic maps that illustrate output statistics.

  17. Long-term EEG in adults: sleep-deprived EEG (SDE), ambulatory EEG (Amb-EEG) and long-term video-EEG recording (LTVER).

    PubMed

    Michel, V; Mazzola, L; Lemesle, M; Vercueil, L

    2015-03-01

    Long-term EEG in adults includes three modalities: sleep deprived-EEG lasting 1 to 3 hours, 24 hours ambulatory-EEG and continuous prolonged video-EEG lasting from several hours to several days. The main indications of long-term EEG are: syndromic classification of epilepsy; search for interictal discharges when epilepsy is suspected or for the purpose of therapeutic evaluation; positive diagnosis of paroxysmal clinical events; and pre-surgical evaluation of drug-resistant epilepsy. Sleep deprived-EEG and ambulatory-EEG are indicated to detect interictal discharges in order to validate a syndromic classification of epilepsy when standard EEG is negative. These exams can help in evaluating treatment efficacy, especially when clinical evaluation is difficult. Long-term video EEG is indicated for drug-resistant epilepsy, to analyze electro-clinical correlations in a pre-surgical evaluation context, and to refine a positive diagnosis when paroxysmal clinical events are frequent.

  18. Influence of the simultaneous addition of the protease flavourzyme and the lipase novozym 677BG on dry fermented sausage compounds extracted by SDE and analyzed by GC-MS.

    PubMed

    Ansorena, D; Astiasarán, I; Bello, J

    2000-06-01

    A dry fermented sausage (chorizo de Pamplona) was elaborated with the simultaneous addition of a lipase (Novozym 677BG) and a protease (Flavourzyme) and ripened during 21 days, in contrast to the control without enzymes and ripened during 35 days. Faster and more intense lipolytic and proteolytic activities were observed in the modified sausage, despite its shorter maturation time. At the end of the ripening, a determination of the profile of compounds extracted by simultaneous distillation-extraction with dichloromethane was carried out. The total amounts of extracted compounds (expressed in milligrams of dodecane per gram of dry matter) were 2.5 in the sausage with enzymes and 1.9 in the control. The chemical groups showing increments due to the use of enzymes were esters (103.5% increment) and acids (87% increment) in both cases due to the greater presence of long-chain fatty acid products. However, development of substances originated from further degradation process of amino acids and free fatty acids did not seem to have taken place.

  19. [Static and dynamic physical loads in rehabilitation of inpatients with ischemic heart disease].

    PubMed

    Nekorkina, O A

    2005-01-01

    Seventy five patients with ischemic heart disease (mean age 55.3 +/- 1.3 years) entered the trial of the effects of static-dynamic exercise (SDE) on central hemodynamics (CHD) and psychophysiological status under condition of hospital rehabilitation. The patients were divided into two groups: the study group (n = 50) performed SDE, control patients (n = 25) did standard dynamic exercise (SDE). SDE did not provoke anginal or ischemic responses on ECG. A single procedure of SDE had a positive effect on myocardial contractility. A course SDE had a greater positive effect on CHD, phase structure of the cardiac cycle, psychophysiological status of the patients. Thus, SDE is safe and can be used in inpatients and outpatients with coronary heart disease.

  20. Performance of electrocatalytic gold coating on bipolar plates for SO2 depolarized electrolyser

    NASA Astrophysics Data System (ADS)

    Santasalo-Aarnio, A.; Lokkiluoto, A.; Virtanen, J.; Gasik, M. M.

    2016-02-01

    One of the largest obstacles for SO2 depolarized electrolyser (SDE) commercialization is the material stability in rough operating conditions. In this work stainless steel bipolar plates have been coated with thin Au layer having bifunctional role: providing electrocatalytic surface for both electrode reactions and simultaneously improves the stainless steel support corrosion tolerance at the potential window of SDE. The stability and performance of the coated bipolar plates were tested in a bench-scale electrolyser set-up and the results indicate that these plates can be utilized as economic catalyst for SDE, moreover, they show corrosion resistance in SDE operation.

  1. Sustainable Development Education in Scottish Schools: The Sleeping Beauty Syndrome

    ERIC Educational Resources Information Center

    McNaughton, Marie Jeanne

    2007-01-01

    This paper reviews and discusses the development of Sustainable Development Education (SDE) policy within the context of the Scottish formal school system. The focus is on the progress, and lack thereof, of implementation of SDE in schools in the light of some of the key curriculum documents and associated political decisions and advisory reports.…

  2. Language and Meaning in Environmental Education: An Overview

    ERIC Educational Resources Information Center

    Stables, Andrew

    2006-01-01

    The devotion of this special issue of EER to the language of environmental and sustainable developmental education (SDE) serves as a timely reminder that SDE cannot simply be seen as a culturally neutral or value-free package that can be "delivered". In a variety of ways, contributors to this volume address the issues involved in re-engineering…

  3. STRENGTHENING STATE DEPARTMENTS OF EDUCATION.

    ERIC Educational Resources Information Center

    CAMPBELL, ROALD F.; AND OTHERS

    MAJOR FINDINGS OF A SUMMER SEMINAR HELD AT THE UNIVERSITY OF CHICAGO IN 1966 DEFINE CURRENT ISSUES RELATED TO STATE DEPARTMENTS OF EDUCATION (SDE) AND LEAD TO 23 RECOMMENDATIONS FOR STRENGTHENING THESE DEPARTMENTS SO THAT THEY MAY BE EFFECTIVE PARTNERS IN THE GOVERNMENT OF EDUCATION. SDE'S ARE EVALUATED WITH RESPECT TO FIVE MAJOR…

  4. Self-disproportionation of enantiomers via achiral gravity-driven column chromatography: A case study of N-acyl-α-phenylethylamines.

    PubMed

    Wzorek, Alicja; Sato, Azusa; Drabowicz, Józef; Soloshonok, Vadim A

    2016-10-07

    Herein we report a study of the self-disproportionation of enantiomers (SDE) via gravity-driven achiral column chromatography of a series of amides derived from 1-phenylethylamine. We demonstrated that structural and electronic factors of the substituents play an important role in the observed magnitude of the SDE. For the first time, the SDE phenomenon of amides with that of thioamides was compared. We demonstrate that, in sharp contrast to amides, the substitution of the sulphur atom for the oxygen in the acyl group, strongly reduced the observed magnitude of the SDE. These results clearly indicate the importance of the hydrogen bonding for the formation of homo/hetero-chiral association responsible for manifestation of the SDE phenomenon.

  5. Impacts of Snow Darkening by Absorbing Aerosols on Eurasian Climate

    NASA Technical Reports Server (NTRS)

    Kim, Kyu-Myong; Lau, William K M.; Yasunari, Teppei J.; Kim, Maeng-Ki; Koster, Randal D.

    2016-01-01

    The deposition of absorbing aerosols on snow surfaces reduces snow-albedo and allows snowpack to absorb more sunlight. This so-called snow darkening effect (SDE) accelerates snow melting and leads to surface warming in spring. To examine the impact of SDE on weather and climate during late spring and early summer, two sets of NASA GEOS-5 model simulations with and without SDE are conducted. Results show that SDE-induced surface heating is particularly pronounced in Eurasian regions where significant depositions of dust transported from the North African deserts, and black carbon from biomass burning from Asia and Europe occur. In these regions, the surface heating due to SDE increases surface skin temperature by 3-6 degrees Kelvin near the snowline in spring. Surface energy budget analysis indicates that SDE-induced excess heating is associated with a large increase in surface evaporation, subsequently leading to a significant reduction in soil moisture, and increased risks of drought and heat waves in late spring to early summer. Overall, we find that rainfall deficit combined with SDE-induced dry soil in spring provide favorable condition for summertime heat waves over large regions of Eurasia. Increased frequency of summer heat waves with SDE and the region of maximum increase in heat-wave frequency are found along the snow line, providing evidence that early snowmelt by SDE may increase the risks of extreme summer heat wave. Our results suggest that climate models that do not include SDE may significantly underestimate the effect of global warming over extra-tropical continental regions.

  6. Assessment of Antioxidant Activity of Spray Dried Extracts of Psidium guajava Leaves by DPPH and Chemiluminescence Inhibition in Human Neutrophils

    PubMed Central

    Fernandes, M. R. V.; Azzolini, A. E. C. S.; Martinez, M. L. L.; Souza, C. R. F.; Lucisano-Valim, Y. M.; Oliveira, W. P.

    2014-01-01

    This work evaluated the physicochemical properties and antioxidant activity of spray dried extracts (SDE) from Psidium guajava L. leaves. Different drying carriers, namely, maltodextrin, colloidal silicon dioxide, Arabic gum, and β-cyclodextrin at concentrations of 40 and 80% relative to solids content, were added to drying composition. SDE were characterized through determination of the total phenolic, tannins, and flavonoid content. Antioxidant potential of the SDE was assessed by two assays: cellular test that measures the luminol-enhanced chemiluminescence (LumCL) produced by neutrophils stimulated with phorbol myristate acetate (PMA) and the DPPH radical scavenging (DPPH∗ method). In both assays the antioxidant activity of the SDE occurred in a concentration-dependent manner and showed no toxicity to the cells. Using the CLlum method, the IC50 ranged from 5.42 to 6.50 µg/mL. The IC50 of the SDE ranged from 7.96 to 8.11 µg/mL using the DPPH• method. Psidium guajava SDE presented significant antioxidant activity; thus they show high potential as an active phytopharmaceutical ingredient. Our findings in human neutrophils are pharmacologically relevant since they indicate that P. guajava SDE is a potential antioxidant and anti-inflammatory agent in human cells. PMID:24822200

  7. Aleurites moluccana (L.) Willd. Leaves: Mechanical Antinociceptive Properties of a Standardized Dried Extract and Its Chemical Markers

    PubMed Central

    Quintão, Nara L. M.; Meyre-Silva, Christiane; Silva, Gislaine F.; Antonialli, Carla S.; Rocha, Lilian W.; Lucinda-Silva, Ruth M.; Malheiros, Angela; Souza, Márcia M.; Cechinel Filho, Valdir; Bresolin, Tania M. B.

    2011-01-01

    Seeking to develop a new analgesic phytomedicine, a spray-dried extract (SDE) of Aleurites moluccana (L.) Willd. leaves was developed in scale up (5 kg). The SDE was standardized at 3% w/w in relation to the flavonoid 2′′-O-rhamnosylswertisin. The SDE batches were evaluated in relation to their physical, physiochemical, and pharmacological characteristics. The results demonstrated the reproducibility of the scale up SDE process which, when dosed orally, reduced carrageenan-induced mechanical hypernociception, with an ID50% of 443 mg/kg. Similar results were obtained with animals injected with complete Freund's adjuvant (CFA), in which SDE caused inhibition of 48 ± 4%. SDE was effective in preventing prostaglandin E2 (PGE2)-induced mechanical hypernociception (inhibition of 26 ± 10% and 33 ± 3%, at 250 and 500 mg/kg, respectively). Swertisin and 2′′-O-rhamnosylswertisin isolated from the own extract were effective in inhibiting the hypernociceptive response induced by carrageenan (70 ± 2% and 50 ± 5%, resp.). Furthermore, 2′′-O-rhamnosylswertisin was capable of significantly inhibiting the mechanical sensitization induced by CFA or PGE2, with inhibitions of 25 ± 3% and 94 ± 6%, respectively. These results suggest that the effects of SDE are related, at least in part, to the presence of these flavonoids. PMID:21660087

  8. An integrated simultaneous distillation-extraction apparatus for the extraction of essential oils from herb materials and its application in Flos Magnoliae.

    PubMed

    Wei, Yuhui; Li, Boxia; Duan, Haogang; Wu, Xin'an; Yao, Xiaojun

    2010-03-01

    A large number of herb materials contain essential oils with extensive bioactivities. In this work, an integrated simultaneous distillation-extraction (ISDE) apparatus was developed. To demonstrate its feasibility, the performance of ISDE was evaluated for the extraction of essential oil from Flos Magnoliae and compared with conventional techniques including steam distillation (SD) and simultaneous distillation-extraction (SDE). According to the product yield, the time consumed and the composition of oil, the essential oils isolated by ISDE were better than that obtained by SD and similar to those obtained by SDE. ISDE was also better than SDE due to its simple operation and lower consumption of energy and organic solvent.

  9. Basic stochastic models for viral infection within a host.

    PubMed

    Vidurupola, Sukhitha W; Allen, Linda J S

    2012-10-01

    Stochastic differential equation (SDE) models are formulated for intra-host virus-cell dynamics during the early stages of viral infection, prior to activation of the immune system. The SDE models incorporate more realism into the mechanisms for viral entry and release than ordinary differential equation (ODE) models and show distinct differences from the ODE models. The variability in the SDE models depends on the concentration, with much greater variability for small concentrations than large concentrations. In addition, the SDE models show significant variability in the timing of the viral peak. The viral peak is earlier for viruses that are released from infected cells via bursting rather than via budding from the cell membrane.

  10. Comparing seed dispersal effectiveness by frugivores at the community level.

    PubMed

    González-Castro, Aarón; Calviño-Cancela, Marĺa; Nogales, Manuel

    2015-03-01

    Seed dispersal effectiveness (SDE) is the contribution of dispersers to plant recruitment and is estimated as the product of the number of seeds dispersed (quantity) and the probability of recruitment of each dispersed seed (quality). Although SDE is a key concept in seed dispersal ecology, few studies estimate SDE and none has a community approach. Oceanic islands, with simple communities, are ideal for this purpose. In this study, we compared the SDE of the main types of dispersers (lizards and passerine birds) at the community level in a given habitat. We estimated SDE using a stochastic simulation model parameterized with empirical data on quantity and quality components measured throughout the recruitment process. Although lizards are highly frugivorous and their density was approximately 20 times higher than that of birds, lizards and birds dispersed a similar quantity of seeds. This may be due to lower intake of seeds by lizards due to their slower metabolism (approximately 20 times lower than birds). This low metabolic rate limits the importance of lizards as seed dispersers, but it is compensated by extraordinarily high lizard densities in the study area (approximately 9600 individuals/km2). High densities of lizards are typical of islands, and this helps to explain why dispersal by lizards seems mainly an island phenomenon. Birds and lizards showed functional complementarity, especially regarding seed dispersal distribution patterns. In fact, lizards dispersed more seeds in shrublands and open sites, and birds in woodlands and beneath canopies, with their joint contribution helping to maximize recruitment. Lizards provided higher SDE than birds for 7 out of 11 plant species. The disperser with a higher quantity for a given plant generally had the higher quality, and plants could be classified as bird- or lizard-dependent for dispersal. This dependence increased when considering SDE instead of dispersal quantity only. Moreover, quality was a better

  11. Replacing and Additive Horizontal Gene Transfer in Streptococcus

    PubMed Central

    Choi, Sang Chul; Rasmussen, Matthew D.; Hubisz, Melissa J.; Gronau, Ilan; Stanhope, Michael J.; Siepel, Adam

    2012-01-01

    The prominent role of Horizontal Gene Transfer (HGT) in the evolution of bacteria is now well documented, but few studies have differentiated between evolutionary events that predominantly cause genes in one lineage to be replaced by homologs from another lineage (“replacing HGT”) and events that result in the addition of substantial new genomic material (“additive HGT”). Here in, we make use of the distinct phylogenetic signatures of replacing and additive HGTs in a genome-wide study of the important human pathogen Streptococcus pyogenes (SPY) and its close relatives S. dysgalactiae subspecies equisimilis (SDE) and S. dysgalactiae subspecies dysgalactiae (SDD). Using recently developed statistical models and computational methods, we find evidence for abundant gene flow of both kinds within each of the SPY and SDE clades and of reduced levels of exchange between SPY and SDD. In addition, our analysis strongly supports a pronounced asymmetry in SPY–SDE gene flow, favoring the SPY-to-SDE direction. This finding is of particular interest in light of the recent increase in virulence of pathogenic SDE. We find much stronger evidence for SPY–SDE gene flow among replacing than among additive transfers, suggesting a primary influence from homologous recombination between co-occurring SPY and SDE cells in human hosts. Putative virulence genes are correlated with transfer events, but this correlation is found to be driven by additive, not replacing, HGTs. The genes affected by additive HGTs are enriched for functions having to do with transposition, recombination, and DNA integration, consistent with previous findings, whereas replacing HGTs seen to influence a more diverse set of genes. Additive transfers are also found to be associated with evidence of positive selection. These findings shed new light on the manner in which HGT has shaped pathogenic bacterial genomes. PMID:22617954

  12. Putative Alginate Assimilation Process of the Marine Bacterium Saccharophagus degradans 2-40 Based on Quantitative Proteomic Analysis.

    PubMed

    Takagi, Toshiyuki; Morisaka, Hironobu; Aburaya, Shunsuke; Tatsukami, Yohei; Kuroda, Kouichi; Ueda, Mitsuyoshi

    2016-02-01

    Quantitative proteomic analysis was conducted to assess the assimilation processes of Saccharophagus degradans cultured with glucose, pectin, and alginate as carbon sources. A liquid chromatography-tandem mass spectrometry approach was used, employing our unique, long monolithic silica capillary column. In an attempt to select candidate proteins that correlated to alginate assimilation, the production of 23 alginate-specific proteins was identified by statistical analyses of the quantitative proteomic data. Based on the analysis, we propose that S. degradans has an alginate-specific gene cluster for efficient alginate utilization. The alginate-specific proteins of S. degradans were comprised of alginate lyases, enzymes related to carbohydrate metabolism, membrane transporters, and transcription factors. Among them, the short-chain dehydrogenase/reductase Sde_3281 annotated in the alginate-specific cluster showed 4-deoxy-L-erythro-5-hexoseulose uronic acid reductase (DehR) activity. Furthermore, we found two different genes (Sde_3280 and Sde_0939) encoding 2-keto-3-deoxy-D-gluconic acid (KDG) kinases (KdgK) that metabolize the KDG derived from alginate and pectin in S. degradans. S. degradans used Sde_3280 to phosphorylate the KDG derived from alginate and Sde_0939 to phosphorylate the KDG derived from pectin. The distinct selection of KdgKs provides an important clue toward the elucidation of how S. degradans recognizes and processes polysaccharides.

  13. Arsenic removal from groundwater of the Chaco-Pampean plain (Argentina) using natural geological materials as adsorbents.

    PubMed

    Bundschuh, Jochen; Bhattacharya, Prosun; Sracek, Ondra; Mellano, M Fernanda; Ramírez, Antonio E; Storniolo, Angel del R; Martín, Raúl A; Cortés, Julia; Litter, Marta I; Jean, Jiin-Shuh

    2011-01-01

    Use of natural geological materials for arsenic (As) removal is an emerging solution at a household level for poor people in remote rural settlements, especially when the materials are locally available and can be collected by the local population. Their low or zero cost makes these materials very attractive compared with synthetic or commercial materials. Sometimes, this may be the only option to provide safe water to very poor settlements. Their suitability for As removal from water is mainly due to adsorption, co-precipitation and ion exchange processes involving Fe- and Al-rich minerals and clay minerals present in the soils or sediments. In the present study, various clay-rich soils from the Santiago del Estero province (SDE, NW Argentina) and, for comparison, a laterite from the Misiones province have been tested as adsorbents for As in shallow naturally contaminated groundwaters of the Río Dulce alluvial aquifer in SDE. Batch adsorption experiments showed higher As(V) removal for the Misiones laterite sample (99 %) as compared with the soils from SDE (40-53 %), which can be related to lower contents of water-soluble and oxalate extractable Al and Fe in the last samples. These results suggest the application of the Misiones laterite soil as an alternative for As removal. However, high transportation costs from Misiones to SDE can be an economical restriction for the low-income population of SDE.

  14. Phase velocity limit of high-frequency photon density waves

    NASA Astrophysics Data System (ADS)

    Haskell, Richard C.; Svaasand, Lars O.; Madsen, Sten; Rojas, Fabio E.; Feng, T.-C.; Tromberg, Bruce J.

    1995-05-01

    In frequency-domain photon migration (FDPM), two factors make high modulation frequencies desirable. First, with frequencies as high as a few GHz, the phase lag versus frequency plot has sufficient curvature to yield both the scattering and absorption coefficients of the tissue under examination. Second, because of increased attenuation, high frequency photon density waves probe smaller volumes, an asset in small volume in vivo or in vitro studies. This trend toward higher modulation frequencies has led us to re-examine the derivation of the standard diffusion equation (SDE) from the Boltzman transport equation. We find that a second-order time-derivative term, ordinarily neglected in the derivation, can be significant above 1 GHz for some biological tissue. The revised diffusion equation, including the second-order time-derivative, is often termed the P1 equation. We compare the dispersion relation of the P1 equation with that of the SDE. The P1 phase velocity is slower than that predicted by the SDE; in fact, the SDE phase velocity is unbounded with increasing modulation frequency, while the P1 phase velocity approaches c/sqrt(3) is attained only at modulation frequencies with periods shorter than the mean time between scatterings of a photon, a frequency regime that probes the medium beyond the applicability of diffusion theory. Finally we caution that values for optical properties deduced from FDPM data at high frequencies using the SDE can be in error by 30% or more.

  15. Weak-noise limit of a piecewise-smooth stochastic differential equation.

    PubMed

    Chen, Yaming; Baule, Adrian; Touchette, Hugo; Just, Wolfram

    2013-11-01

    We investigate the validity and accuracy of weak-noise (saddle-point or instanton) approximations for piecewise-smooth stochastic differential equations (SDEs), taking as an illustrative example a piecewise-constant SDE, which serves as a simple model of Brownian motion with solid friction. For this model, we show that the weak-noise approximation of the path integral correctly reproduces the known propagator of the SDE at lowest order in the noise power, as well as the main features of the exact propagator with higher-order corrections, provided the singularity of the path integral associated with the nonsmooth SDE is treated with some heuristics. We also show that, as in the case of smooth SDEs, the deterministic paths of the noiseless system correctly describe the behavior of the nonsmooth SDE in the low-noise limit. Finally, we consider a smooth regularization of the piecewise-constant SDE and study to what extent this regularization can rectify some of the problems encountered when dealing with discontinuous drifts and singularities in SDEs.

  16. Response to "Comment on `Construction of the landscape for multi-stable systems: Potential landscape, quasi-potential, A-type integral and beyond"' [J. Chem. Phys. 145, 147104 (2016)

    NASA Astrophysics Data System (ADS)

    Zhou, Peijie; Li, Tiejun

    2016-10-01

    The uniqueness issue of SDE decomposition theory proposed by Ao and his co-workers has recently been discussed. A comprehensive study to investigate connections among different landscape theories [J. Chem. Phys. 144, 094109 (2016)] has pointed out that the decomposition is generally not unique, while Ao et al. recently argue that such conclusions are "incorrect" because the uniqueness of the decomposition for Ornstein-Uhlenbeck (O-U) process has been claimed before. In this response, we will demonstrate that the claimed "uniqueness" of the O-U process decomposition is invalid to serve as a counterexample according to the original definition of SDE decomposition. The absence of effective and concrete boundary conditions in previous SDE decomposition papers will be pointed out, and some other issues in the comment will also be responded.

  17. Finitely approximable random sets and their evolution via differential equations

    NASA Astrophysics Data System (ADS)

    Ananyev, B. I.

    2016-12-01

    In this paper, random closed sets (RCS) in Euclidean space are considered along with their distributions and approximation. Distributions of RCS may be used for the calculation of expectation and other characteristics. Reachable sets on initial data and some ways of their approximate evolutionary description are investigated for stochastic differential equations (SDE) with initial state in some RCS. Markov property of random reachable sets is proved in the space of closed sets. For approximate calculus, the initial RCS is replaced by a finite set on the integer multidimensional grid and the multistage Markov chain is substituted for SDE. The Markov chain is constructed by methods of SDE numerical integration. Some examples are also given.

  18. A Maximum Principle for SDEs of Mean-Field Type

    SciTech Connect

    Andersson, Daniel Djehiche, Boualem

    2011-06-15

    We study the optimal control of a stochastic differential equation (SDE) of mean-field type, where the coefficients are allowed to depend on some functional of the law as well as the state of the process. Moreover the cost functional is also of mean-field type, which makes the control problem time inconsistent in the sense that the Bellman optimality principle does not hold. Under the assumption of a convex action space a maximum principle of local form is derived, specifying the necessary conditions for optimality. These are also shown to be sufficient under additional assumptions. This maximum principle differs from the classical one, where the adjoint equation is a linear backward SDE, since here the adjoint equation turns out to be a linear mean-field backward SDE. As an illustration, we apply the result to the mean-variance portfolio selection problem.

  19. Feasibility Study of PM Elimination by Silent Discharge Type of DPF under Room Temperature and Atmospheric Pressure Condition

    NASA Astrophysics Data System (ADS)

    Chuubachi, Minoru; Nagasawa, Takeshi

    This Silent Discharge type of DPF (Diesel Particulate Filter) has been studied for eliminating PM (Particulate Mater) we call it “SDeDPF”. Usually, exhaust gas temperature of diesel engines is under 200 or 250°C at normal city driving condition. Under that condition, generally PM is not bourn out in the normal ceramic DPF. This SDeDPF aims to remove PM electrically and chemically even at room temperature and atmospheric pressure continuously. Finally, in the basic lab test result, 95.6% reduction of PM has been verified by SDeDPF with a special MFS (Metal Fiber Sheet) for discharge electrode to reduce a back pressure, a special Turbulent Block for turbulent and slower velocity of exhaust gas, the 1mm gap between electrodes and an optimum total area of piled electrodes. Also, 98.1% reduction of PM could be designed by most suitable gap between electrodes.

  20. Polymicrobial subdural empyema: involvement of Streptococcus pneumoniae revealed by lytA PCR and antigen detection.

    PubMed

    Greve, Thomas; Clemmensen, Dorte; Ridderberg, Winnie; Pedersen, Lisbeth N; Møller, Jens K

    2011-03-01

    The authors report a case of a subdural empyema (SDE) caused by a coinfection with Streptococcus intermedius and Streptococcus pneumoniae, initially considered a S. intermedius infection only. An otherwise healthy 11-year-old female was admitted to the hospital after 5 days of illness. Symptoms were consistent with classical SDE symptoms and progressed rapidly with finally somnolence before the first neurosurgical procedure despite relevant antibiotic treatment. Primary MRI showed an interhemispheric SDE and a postoperative control CT scan showed progression of the empyema infratentorially. The empyema was evacuated twice, day 8 and 18, with good results. Primary samples showed growth of S. intermedius only. The severity of the clinical picture elicited supplementary samples, which were additionally positive for S. pneumoniae by an in-house specific lytA PCR and/or a commercial antigen test.

  1. Contribution by vertebrates to seed dispersal effectiveness in the Galápagos Islands: A community-wide approach.

    PubMed

    Nogales, M; González-Castro, A; Rumeu, B; Traveset, A; Vargas, P; Jaramillo, P; Olesen, J M; Heleno, R

    2017-03-17

    Seed dispersal and seedling recruitment are crucial phases in the life cycle of all spermatophyte plants. The net contribution of seed dispersers to plant establishment is known as seed dispersal effectiveness (SDE) and is defined as the product of a quantitative (number of seeds dispersed) and a qualitative (probability of recruitment) component. In Galápagos, we studied the direct contribution to SDE (number of seeds dispersed and effect on seedling emergence) provided by the five island groups of frugivores (giant tortoises, lizards, medium-sized passerine birds, small non-finch passerine birds and finches) in the two main habitats in this archipelago: the lowland and the highland zones, and found 16 vertebrate species dispersing 58 plant species. Data on frequency of occurrence of seeds in droppings and number of seeds dispersed per unit area produced contrasting patterns of seed dispersal. Based on the former, giant tortoises and medium-sized passerines were the most important seed dispersers. However, based on the latter, small non-finch passerines were the most important dispersers, followed by finches and medium-sized passerines. The effect of disperser gut passage on seedling emergence varied greatly depending on both, the disperser and the plant species. Although the contribution to SDE provided by different disperser guilds changed across plant species, medium-sized passerines (e.g. mockingbirds) provided a higher contribution to SDE than lava lizards in ten out of 16 plant species analysed, whereas lava lizards provided a higher contribution to SDE than birds in fiveplant species. While both the quantitative and qualitative components addressed are important, our data suggests that the former is a better predictor of SDE in the Galápagos archipelago. This article is protected by copyright. All rights reserved.

  2. Changes of volatile compounds during heating of bacuri pulp.

    PubMed

    Boulanger, R; Crouzet, J

    2001-12-01

    The formation of volatile compounds from precursors or through chemical rearrangement during heat treatment of bacuri pulp at fruit natural pH were studied using simultaneous distillation/extraction (SDE) technique. An increase of the quantities of oxygenated and hydrocarbon terpenes and, to a lesser degree, aldehydes, was observed after SDE at pH 3, relative to the other extraction methods used, SDE at neutral pH and solid phase extraction (SPE). More particularly, linalool, linalool furanoxides, alpha-terpineol, hotrienol, nerol oxide, nerol, and geraniol were isolated in more important quantities after the first treatment than after the others. These results can be partially explained by the hydrolysis of glycosidically bound compounds previously identified in bacuri. Other pathways such as polyol rearrangements were also involved. The formation of linalool and alpha-terpineol was probably the result of the rearrangement of 2,6-dimethyloct-1-ene-3,7-diol. Moreover, it was assumed that oxidation reactions occurred during SDE at pH 3; more particularly, linalool pyranoxides partially resulted from nonenzymatic oxidation of linalool. When SDE was performed at pH 3, an increase of furfural and 4-methoxy-2,5-dimethyl-3(2H)-furanone was noticed. The modifications of the concentration of aliphatic aldehydes, known as lipid oxidation compounds, and of fatty acid esters were in good agreement with the observed decrease of palmitic and linoleic acid concentrations during this treatment. Moreover, important amounts of 2-acetyl-1-pyrroline were found in the SDE extract recovered at pH 7.

  3. The use of copulas to practical estimation of multivariate stochastic differential equation mixed effects models

    SciTech Connect

    Rupšys, P.

    2015-10-28

    A system of stochastic differential equations (SDE) with mixed-effects parameters and multivariate normal copula density function were used to develop tree height model for Scots pine trees in Lithuania. A two-step maximum likelihood parameter estimation method is used and computational guidelines are given. After fitting the conditional probability density functions to outside bark diameter at breast height, and total tree height, a bivariate normal copula distribution model was constructed. Predictions from the mixed-effects parameters SDE tree height model calculated during this research were compared to the regression tree height equations. The results are implemented in the symbolic computational language MAPLE.

  4. The use of copulas to practical estimation of multivariate stochastic differential equation mixed effects models

    NASA Astrophysics Data System (ADS)

    Rupšys, P.

    2015-10-01

    A system of stochastic differential equations (SDE) with mixed-effects parameters and multivariate normal copula density function were used to develop tree height model for Scots pine trees in Lithuania. A two-step maximum likelihood parameter estimation method is used and computational guidelines are given. After fitting the conditional probability density functions to outside bark diameter at breast height, and total tree height, a bivariate normal copula distribution model was constructed. Predictions from the mixed-effects parameters SDE tree height model calculated during this research were compared to the regression tree height equations. The results are implemented in the symbolic computational language MAPLE.

  5. A view of software management issues

    NASA Technical Reports Server (NTRS)

    Manley, J. H.

    1985-01-01

    The Software Development Environment (SDE) Panel addressed key programmatic, scope, and structural issues raised by its members and the general audience regarding the proposed software development environment for the Space Station program. The general team approach taken by this group led to a consensus on 18 recommendations to NASA mangament regarding the acquisition and definition of the SDE. This approach was keyed by the initial issues presentation given to the general audience. Additional issues (for a total of 23) were developed by the panelists in their first closed session from which key areas were selected and discussed in open session. These discussions led to key recommendations which are summarized and described.

  6. U.S. Army Corps of Engineers Geospatial Data and Systems Management

    DTIC Science & Technology

    2000-11-01

    75.2.1. Filtering UPS 75.2.2. Surge protectors 75.2.3. Other 76. How do you protect data from physical computer faults (crashes)? 76.1. Client computers...coverages were converted to ArcView shapefiles . These were loaded into the database with SDE functions that essentially create database tables with columns...configured automatically to match the ArcView shapefile table designs. The LMV REEGIS data required use of the SDE CADD client software because the

  7. Stochastic modeling for characterisation of biofilm development with discrete detachment events (sloughing).

    PubMed

    Bohn, A; Zippel, B; Almeida, J S; Xavier, J B

    2007-01-01

    The monitoring of biofilm development at a small-scale is often observed to be a stochastic process. This raises important issues concerning the reproducibility of biofilm growth monitoring experiments. By realising that there are limits to the latter, a model of biofilm accumulation curves that takes into account the dynamics of seemingly random fluctuations resulting from sloughing events is proposed. The model is derived from a stochastic differential equation (SDE) based on the logistic equation, adding a stochastic term for the sloughing events and measurement noise. Experimental light absorbance data that correlate with biofilm biomass obtained from the development of phototrophic biofilms are analysed to illustrate the use of SDE modeling.

  8. Multilevel ensemble Kalman filtering

    DOE PAGES

    Hoel, Hakon; Law, Kody J. H.; Tempone, Raul

    2016-06-14

    This study embeds a multilevel Monte Carlo sampling strategy into the Monte Carlo step of the ensemble Kalman filter (EnKF) in the setting of finite dimensional signal evolution and noisy discrete-time observations. The signal dynamics is assumed to be governed by a stochastic differential equation (SDE), and a hierarchy of time grids is introduced for multilevel numerical integration of that SDE. Finally, the resulting multilevel EnKF is proved to asymptotically outperform EnKF in terms of computational cost versus approximation accuracy. The theoretical results are illustrated numerically.

  9. Which Aspects of the English Language Do Distance Learners Find Difficult?

    ERIC Educational Resources Information Center

    Teoh, George Boon Sai; Lin, Agnes Liau Wei; Belaja, Kathy

    2016-01-01

    This study reports the findings of a research carried out on distance learners at the School of Distance Education (SDE), University Sains Malaysia (USM). The study was explorative in nature with the purpose identifying the aspects of the English language which distance learners found difficult to learn. A quantitative survey questionnaire design…

  10. Anticancer and Anti-Inflammatory Activities of a Standardized Dichloromethane Extract from Piper umbellatum L. Leaves

    PubMed Central

    Iwamoto, Leilane Hespporte; Vendramini-Costa, Débora Barbosa; Monteiro, Paula Araújo; Ruiz, Ana Lúcia Tasca Gois; Sousa, Ilza Maria de Oliveira; Foglio, Mary Ann; de Carvalho, João Ernesto; Rodrigues, Rodney Alexandre Ferreira

    2015-01-01

    Despite the advances in anticancer drug discovery field, the worldwide cancer incidence is remarkable, highlighting the need for new therapies focusing on both cancer cell and its microenvironment. The tumor microenvironment offers multiple targets for cancer therapy, including inflammation. Nowadays, almost 75% of the anticancer agents used in chemotherapy are derived from natural products, and plants are an important source of new promising therapies. Continuing our research on Piper umbellatum species, here we describe the anticancer (in vitro antiproliferative activity and in vivo Ehrlich solid tumor model) and anti-inflammatory (carrageenan-induced paw edema and peritonitis models) activities of a standardized dichloromethane extract (SDE) from P. umbellatum leaves, containing 23.9% of 4-nerolidylcatechol. SDE showed in vitro and in vivo antiproliferative activity, reducing Ehrlich solid tumor growth by 38.7 and 52.2% when doses of 200 and 400 mg/kg, respectively, were administered daily by oral route. Daily treatments did not produce signals of toxicity. SDE also reduced paw edema and leukocyte migration on carrageenan-induced inflammation models, suggesting that the anticancer activity of SDE from Piper umbellatum leaves could involve antiproliferative and anti-inflammatory effects. These findings highlight P. umbellatum as a source of compounds against cancer and inflammation. PMID:25713595

  11. Simultaneous distillation-extraction of high-value volatile compounds from Cistus ladanifer L.

    PubMed

    Teixeira, Salomé; Mendes, Adélio; Alves, Arminda; Santos, Lúcia

    2007-02-19

    The present paper describes a procedure to isolate volatiles from rock-rose (Cistus ladanifer L.) using simultaneous distillation-extraction (SDE). High-value volatile compounds (HVVC) were selected and the influence of the extraction conditions investigated. The effect of the solvent nature and extraction time on SDE efficiency was studied. The best performance was achieved with pentane in 1 h operation. The extraction efficiencies ranged from 65% to 85% and the repeatability varied between 4% and 6% (as a CV%). The C. ladanifer SDE extracts were analysed by headspace solid phase microextraction (HS-SPME) followed by gas chromatography with flame ionization detection (GC-FID). The HS-SPME sampling conditions such as fiber coating, temperature, ionic strength and exposure time were optimized. The best results were achieved with an 85 microm polyacrylate fiber for a 60 min headspace extraction at 40 degrees C with 20% (w/v) of NaCl. For optimized conditions the recovery was in average higher than 90% for all compounds and the intermediate precision ranged from 4 to 9% (as CV %). The volatiles alpha-pinene (22.2 mg g(-1) of extract), 2,2,6-trimethylcyclohexanone (6.1 mg g(-1) of extract), borneol (3.0 mg g(-1) of extract) and bornyl acetate (3.9 mg g(-1) of extract) were identified in the SDE extracts obtained from the fresh plant material.

  12. Ethanol extract of Synurus deltoides (Aiton) Nakai suppresses in vitro LPS-induced cytokine production in RAW 264.7 macrophages and in vivo acute inflammatory symptoms

    PubMed Central

    Jiang, Yunyao

    2014-01-01

    Synurus deltoides (Aiton) Nakai, belonging to the Compositae family, is an edible plant widely distributed in Northeast Asia. In this study, we examined the mechanisms underlying the immunomodulative effects of the ethanol extract of S. deltoides (SDE). The SDE extract strongly down-regulated the mRNA expression of the inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and tumour necrosis factor (TNF)-α, thereby inhibiting the production of nitric oxide (NO), prostaglandin E2 (PGE2), and TNF-α in the lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Furthermore, SDE also suppressed the nuclear translocation of the activation protein (AP)-1 and the nuclear factor-κB (NF-κB), and simultaneously decreased the phosphorylation of extracellular signal-regulated protein kinases (ERK), p38, and Akt. In agreement with the in vitro observations, the orally administered SDE ameliorated the acute inflammatory symptoms in the arachidonic acid-induced ear edema and the EtOH/HCl-induced gastritis in mice. Therefore, S. deltoides have a potential anti-inflammatory capacity in vitro and in vivo, suggesting the potential therapeutic use in the inflammation-associated disorders. PMID:24611100

  13. How many biological replicates are needed in an RNA-seq experiment and which differential expression tool should you use?

    PubMed Central

    Gierliński, Marek; Sherstnev, Alexander; Singh, Vijender; Wrobel, Nicola; Gharbi, Karim; Simpson, Gordon G.; Owen-Hughes, Tom; Blaxter, Mark

    2016-01-01

    RNA-seq is now the technology of choice for genome-wide differential gene expression experiments, but it is not clear how many biological replicates are needed to ensure valid biological interpretation of the results or which statistical tools are best for analyzing the data. An RNA-seq experiment with 48 biological replicates in each of two conditions was performed to answer these questions and provide guidelines for experimental design. With three biological replicates, nine of the 11 tools evaluated found only 20%–40% of the significantly differentially expressed (SDE) genes identified with the full set of 42 clean replicates. This rises to >85% for the subset of SDE genes changing in expression by more than fourfold. To achieve >85% for all SDE genes regardless of fold change requires more than 20 biological replicates. The same nine tools successfully control their false discovery rate at ≲5% for all numbers of replicates, while the remaining two tools fail to control their FDR adequately, particularly for low numbers of replicates. For future RNA-seq experiments, these results suggest that at least six biological replicates should be used, rising to at least 12 when it is important to identify SDE genes for all fold changes. If fewer than 12 replicates are used, a superior combination of true positive and false positive performances makes edgeR and DESeq2 the leading tools. For higher replicate numbers, minimizing false positives is more important and DESeq marginally outperforms the other tools. PMID:27022035

  14. Multivariate Linear Predictive Spectral Analysis Employing Weighted Forward and Backward Averaging: A Generalization of Burg’s Algorithm

    DTIC Science & Technology

    1976-10-13

    Filter Maximum Entropy Weighted Error Matrices 20. ABSTRACT (Contlinue on revrse sde f neceesry and Identify b- *ock numbfb) A method for multivariate... maximum entropy , and autoregressive techniques has attracted much attention lately, especially for short data segments; see, for example, the biblio...individually predicted waveform values. The correlation values in (52) are called the maximum entropy correlation extrapolations. The recursion is stable

  15. Using spline-enhanced ordinary differential equations for PK/PD model development.

    PubMed

    Wang, Yi; Eskridge, Kent; Zhang, Shunpu; Wang, Dong

    2008-10-01

    A spline-enhanced ordinary differential equation (ODE) method is proposed for developing a proper parametric kinetic ODE model and is shown to be a useful approach to PK/PD model development. The new method differs substantially from a previously proposed model development approach using a stochastic differential equation (SDE)-based method. In the SDE-based method, a Gaussian diffusion term is introduced into an ODE to quantify the system noise. In our proposed method, we assume an ODE system with form dx/dt = A(t)x + B(t) where B(t) is a nonparametric function vector that is estimated using penalized splines. B(t) is used to construct a quantitative measure of model uncertainty useful for finding the proper model structure for a given data set. By means of two examples with simulated data, we demonstrate that the spline-enhanced ODE method can provide model diagnostics and serve as a basis for systematic model development similar to the SDE-based method. We compare and highlight the differences between the SDE-based and the spline-enhanced ODE methods of model development. We conclude that the spline-enhanced ODE method can be useful for PK/PD modeling since it is based on a relatively uncomplicated estimation algorithm which can be implemented with readily available software, provides numerically stable, robust estimation for many models, is distribution-free and allows for identification and accommodation of model deficiencies due to model misspecification.

  16. Biochemical and Structural Characterization of a Five-domain GH115 α-Glucuronidase from the Marine Bacterium Saccharophagus degradans 2-40 T

    SciTech Connect

    Wang, Weijun; Yan, Ruoyu; Nocek, Boguslaw P.; Vuong, Thu V.; Di Leo, Rosa; Xu, Xiaohui; Cui, Hong; Gatenholm, Paul; Toriz, Guillermo; Tenkanen, Maija; Savchenko, Alexei; Master, Emma R.

    2016-04-18

    Glucuronic acid (GlcAp) and/or methylglucuronic acid (MeGlcAp) decorate the major forms of xylan in hardwood and coniferous softwoods as well as many cereal grains. Accordingly, the complete utilization of glucuronoxylans or conversion to sugar precursors requires the action of main chain xylanases as well as -glucuronidases that release the - (132)-linked (Me)GlcAp side groups. Herein, a family GH115 enzyme from the marine bacterium Saccharophagus degradans 2-40T, SdeAgu115A, demonstrated activity toward glucuronoxylan and oligomers thereof with preference toward MeGlcAp linked to internal xylopyranosyl residues. Unique biochemical characteristics of NaCl activation were also observed. The crystal structure of SdeAgu115A revealed a five-domain architecture, with an additional insertion C domain that had significant impact on the domain arrangement of SdeAgu115A monomer and its dimerization. The participation of domain C in substrate binding was supported by reduced substrate inhibition upon introducing W773A, W689A, and F696A substitutions within this domain. In addition to Asp-335, the catalytic essentiality of Glu-216 was revealed by site-specific mutagenesis. A primary sequence analysis suggested that the SdeAgu115A architecture is shared by more than half of GH115 members, thus defining a distinct archetype for GH115 enzymes.

  17. Comparing the Ideal Dispositions of Administrative Internship Candidates

    ERIC Educational Resources Information Center

    Brown, Sidney L.

    2015-01-01

    This research will examine the dispositions of Instructional Leader Residents/interns (ILR/I's) at a State Department of Education (SDE) mandated redesigned masters principal preparation program at a Predominantly White Institution (PWI). Once the dispositions' findings were tabulated they were compared with the dispositions findings of…

  18. Anticancer and Anti-Inflammatory Activities of a Standardized Dichloromethane Extract from Piper umbellatum L. Leaves.

    PubMed

    Iwamoto, Leilane Hespporte; Vendramini-Costa, Débora Barbosa; Monteiro, Paula Araújo; Ruiz, Ana Lúcia Tasca Gois; Sousa, Ilza Maria de Oliveira; Foglio, Mary Ann; de Carvalho, João Ernesto; Rodrigues, Rodney Alexandre Ferreira

    2015-01-01

    Despite the advances in anticancer drug discovery field, the worldwide cancer incidence is remarkable, highlighting the need for new therapies focusing on both cancer cell and its microenvironment. The tumor microenvironment offers multiple targets for cancer therapy, including inflammation. Nowadays, almost 75% of the anticancer agents used in chemotherapy are derived from natural products, and plants are an important source of new promising therapies. Continuing our research on Piper umbellatum species, here we describe the anticancer (in vitro antiproliferative activity and in vivo Ehrlich solid tumor model) and anti-inflammatory (carrageenan-induced paw edema and peritonitis models) activities of a standardized dichloromethane extract (SDE) from P. umbellatum leaves, containing 23.9% of 4-nerolidylcatechol. SDE showed in vitro and in vivo antiproliferative activity, reducing Ehrlich solid tumor growth by 38.7 and 52.2% when doses of 200 and 400 mg/kg, respectively, were administered daily by oral route. Daily treatments did not produce signals of toxicity. SDE also reduced paw edema and leukocyte migration on carrageenan-induced inflammation models, suggesting that the anticancer activity of SDE from Piper umbellatum leaves could involve antiproliferative and anti-inflammatory effects. These findings highlight P. umbellatum as a source of compounds against cancer and inflammation.

  19. Intrinsic Location Parameter of a Diffusion Process

    DTIC Science & Technology

    1998-03-18

    intrins�que du filtre de Kalman , discut�e dans un autre article. Nous pr�sentons ici une simulation num�rique dÕune EDS non lin�aire, qui montre la pr...the construction of an intrinsic nonlinear analog to the Kalman Fil- ter. We present here a numerical simulation of a nonlinear SDE, showing how well

  20. The hallucinogenic herb Salvia divinorum and its active ingredient salvinorin A inhibit enteric cholinergic transmission in the guinea-pig ileum.

    PubMed

    Capasso, R; Borrelli, F; Capasso, F; Siebert, D J; Stewart, D J; Zjawiony, J K; Izzo, A A

    2006-01-01

    Salvia divinorum is a widespread hallucinogenic herb traditionally employed for divination, as well as a medicament for several disorders including disturbances of gastrointestinal motility. In the present study we evaluated the effect of a standardized extract from the leaves of S. divinorum (SDE) on enteric cholinergic transmission in the guinea-pig ileum. SDE reduced electrically evoked contractions without modifying the contractions elicited by exogenous acetylcholine, thus suggesting a prejunctional site of action. The inhibitory effect of SDE on twitch response was abolished by the opioid receptor antagonist naloxone and by the kappa-opioid antagonist nor-binaltorphimine, but not by naltrindole (a delta-opioid receptor antagonist), CTOP (a mu-opioid receptor antagonist), thioperamide (a H(3) receptor antagonist), yohimbine (an alpha(2)-receptor antagonist), methysergide (a 5-hydroxytryptamine receptor antagonist), N(G)-nitro-L-arginine methyl ester (an inhibitor of NO synthase) or apamin (a blocker of Ca(2+)-activated K(+) channels). Salvinorin A, the main active ingredient of S. divinorum, inhibited in a nor-binaltorphimine- and naloxone-sensitive manner electrically induced contractions. It is concluded that SDE depressed enteric cholinergic transmission likely through activation of kappa-opioid receptors and this may provide the pharmacological basis underlying its traditional antidiarrhoeal use. Salvinorin A might be the chemical ingredient responsible for this activity.

  1. Antibacterial and antioxidant activities and chemical compositions of volatile oils extracted from Schisandra chinensis Baill. seeds using simultaneous distillation extraction method, and comparison with Soxhlet and microwave-assisted extraction.

    PubMed

    Teng, Hui; Lee, Won Y

    2014-01-01

    The volatile oils were isolated from dried Schisandra chinensis Baill. seeds by Soxhlet extraction (SE), microwave-assisted extraction (MAE), and simultaneous distillation extraction (SDE), and fractions were identified by gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). The essential oils were assessed for their antioxidant and antibacterial activities. GC-MS results also revealed that the major ingredients in the oil extracted by SDE were terpenoids compounds such as ylangene (15.01%), α-phellandrene (8.23%), β-himachalene (6.95%), and cuparene (6.74), and the oil extracts of MAE and SE mainly contained aromatics such as schizandrins, wuweizisu C, and gomisin A. HPLC analysis results confirmed that more schizandrin was obtained through extraction by MAE (996.64 μg/g) and SE (722.13 μg/g). SDE oil extract showed more significant antioxidant activity than MAE or SE oil. Only volatile oil from SDE showed good antibacterial activity against all tested strains.

  2. 75 FR 53075 - Science and Technology Reinvention Laboratory Personnel Management Demonstration Project...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ..., and skill to increase work force and organizational effectiveness and efficiency.'' \\1\\ \\1\\ Federal... employees may be assigned duties outside their SDE and perhaps would not be given appropriate job skills... for additional experience and contribution. If the skill codes of a position change over time,...

  3. 75 FR 27865 - Science and Technology Reinvention Laboratory Personnel Management Demonstration Project...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    ... * * * ``can help managers to operate with more authority, responsibility, and skill to increase work force and... the SDE. 5. Skill Codes The AF presently uses skill code sets within the Defense Civilian Personnel... personnel into, out of, and within the Demonstration Project, the AF system of skills coding continues to...

  4. Volatile components and key odorants of fennel (Foeniculum vulgare Mill.) and thyme (Thymus vulgaris L.) oil extracts obtained by simultaneous distillation-extraction and supercritical fluid extraction.

    PubMed

    Díaz-Maroto, M Consuelo; Díaz-Maroto Hidalgo, Ignacio Javier; Sánchez-Palomo, Eva; Pérez-Coello, M Soledad

    2005-06-29

    Volatile oil extracts of fennel seeds (Foeniculum vulgare Mill.) and thyme leaves (Thymus vulgaris L.) were obtained by simultaneous distillation-extraction (SDE) and supercritical fluid extraction (SFE) and analyzed by gas chromatography-mass spectrometry (GC-MS). In general, fennel oil extracted by SDE and SFE showed similar compositions, with trans-anethole, estragole, and fenchone as the main components. In contrast, thymol and p-cymene, the most abundant compounds in thyme leaves, showed big differences, with generally higher amounts of monoterpenes obtained by SDE. However, in this case, the differences between the extracts were higher. Key odorants of fennel seeds determined by gas chromatography-olfactometry (GC-O) showed similar patterns when applying SDE and SFE. trans-Anethole (anise, licorice), estragole (anise, licorice, sweet), fenchone (mint, camphor, warm), and 1-octen-3-ol (mushroom) were the most intense odor compounds detected in fennel extracts. Thymol and carvacrol, with oregano, thyme, and spicy notes, were identified as key compounds contributing to the aroma of thyme leaves.

  5. A Synchronous Distance Education Course for Non-Scientists Coordinated among Three Universities

    ERIC Educational Resources Information Center

    Smith, Tamara Floyd; Baah, David; Bradley, James; Sidler, Michelle; Hall, Rosine; Daughtrey, Terrell; Curtis, Christine

    2010-01-01

    A Synchronous Distance Education (SDE) course, jointly offered by Auburn University, Tuskegee University and Auburn University at Montgomery, introduced non-science majors to the concepts of nanoscience. Lectures originated from each of the three campuses during the semester, and video conferencing equipment allowed students at all three campuses…

  6. Effects of time-of-day and partial sleep deprivation on short-term maximal performances of judo competitors.

    PubMed

    Souissi, Nizar; Chtourou, Hamdi; Aloui, Asma; Hammouda, Omar; Dogui, Mohamed; Chaouachi, Anis; Chamari, Karim

    2013-09-01

    This study assessed the effects of partial sleep deprivation on short-term maximal performances of judokas in the morning and afternoon of the following day. In a randomized design, 12 judokas completed the maximal voluntary contraction, the handgrip, and the Wingate tests before and after a judo combat. Measurements were performed at 09:00 and 16:00 hours after a reference-normal sleep night and 2 conditions of 4-hour partial sleep deprivation timed at the beginning (SDB) or at the end of the night (SDE). The results showed that muscle power and strength were significantly higher at 16:00 than 09:00 hours (p < 0.05). These diurnal variations disappeared after SDB and SDE and after the combat. In addition, SDE resulted in significant decreases of short-term maximal performance in the afternoon (p < 0.01). In conclusion, SDE decreased muscle strength and power at 16:00 hours and, therefore, might have blunted the diurnal variations of short-term maximal exercise. Thus, early rising is more detrimental than late bedtime to muscle strength and power for judo athletes when competitions are scheduled in the afternoon hours.

  7. Modeling ion channel dynamics through reflected stochastic differential equations

    NASA Astrophysics Data System (ADS)

    Dangerfield, Ciara E.; Kay, David; Burrage, Kevin

    2012-05-01

    Ion channels are membrane proteins that open and close at random and play a vital role in the electrical dynamics of excitable cells. The stochastic nature of the conformational changes these proteins undergo can be significant, however current stochastic modeling methodologies limit the ability to study such systems. Discrete-state Markov chain models are seen as the “gold standard,” but are computationally intensive, restricting investigation of stochastic effects to the single-cell level. Continuous stochastic methods that use stochastic differential equations (SDEs) to model the system are more efficient but can lead to simulations that have no biological meaning. In this paper we show that modeling the behavior of ion channel dynamics by a reflected SDE ensures biologically realistic simulations, and we argue that this model follows from the continuous approximation of the discrete-state Markov chain model. Open channel and action potential statistics from simulations of ion channel dynamics using the reflected SDE are compared with those of a discrete-state Markov chain method. Results show that the reflected SDE simulations are in good agreement with the discrete-state approach. The reflected SDE model therefore provides a computationally efficient method to simulate ion channel dynamics while preserving the distributional properties of the discrete-state Markov chain model and also ensuring biologically realistic solutions. This framework could easily be extended to other biochemical reaction networks.

  8. Proceedings of the 1991 SPE annual technical conference and exhibition

    SciTech Connect

    Not Available

    1991-01-01

    This book contains the proceedings of the 1991 SDE Annual Technical Conference and Exhibition with some of the following topics. A comparison of MWD and wireless steering tool guidance systems in horizontal drilling; Anger TLP; Drilling engineering overview; Safety of casing shoe test and casing shoe integrity after testing; Zero discharge design considerations for jackey drilling rigs.

  9. Quantifying the Aerosol Semi-Direct Effect in the NASA GEOS-5 AGCM

    NASA Technical Reports Server (NTRS)

    Randles, Cynthia A.; Colarco, Peter R.; daSilva, Arlindo

    2011-01-01

    Aerosols such as black carbon, dust, and some organic carbon species both scatter and absorb incoming solar radiation. This direct aerosol radiative forcing (DARF) redistributes solar energy both by cooling the surface and warming the atmosphere. As a result, these aerosols affect atmospheric stability and cloud cover (the semi-direct effect, or SDE). Furthermore, in regions with persistent high loadings of absorbing aerosols (e.g. Asia), regional circulation patterns may be altered, potentially resulting in changes in precipitation patterns. Here we investigate aerosol-climate coupling using the NASA Goddard Earth Observing System model version 5 (GEOS-5) atmospheric general circulation model (AGCM), in which we have implemented an online version of the Goddard Chemistry, Aerosol, Radiation and Transport (GOCART) model. GOCART includes representations of the sources, sinks, and chemical transformation of externally mixed dust, sea salt, sulfate, and carbonaceous aerosols. We examine a series of free-running ensemble climate simulations of the present-day period (2000-2009) forced by observed sea surface temperatures to determine the impact of aerosols on the model climate. The SDE and response of each simulation is determined by differencing with respect to the control simulation (no aerosol forcing). In a free-running model, any estimate of the SDE includes changes in clouds due both to atmospheric heating from aerosols and changes in circulation. To try and quantify the SDE without these circulation changes we then examine the DARF and SDE in GEOS-5 with prescribed meteorological analyses introduced by the MERRA analysis. By doing so, we are able to examine changes in model clouds that occur on shorter scales (six hours). In the GEOS-5 data assimilation system (DAS), the analysis is defined as the best estimate of the atmospheric state at any given time, and it is determined by optimally combining a first-guess short-term GCM forecast with all available

  10. Evaluation of Uncertainty in Runoff Analysis Incorporating Theory of Stochastic Process

    NASA Astrophysics Data System (ADS)

    Yoshimi, Kazuhiro; Wang, Chao-Wen; Yamada, Tadashi

    2015-04-01

    The aim of this paper is to provide a theoretical framework of uncertainty estimate on rainfall-runoff analysis based on theory of stochastic process. SDE (stochastic differential equation) based on this theory has been widely used in the field of mathematical finance due to predict stock price movement. Meanwhile, some researchers in the field of civil engineering have investigated by using this knowledge about SDE (stochastic differential equation) (e.g. Kurino et.al, 1999; Higashino and Kanda, 2001). However, there have been no studies about evaluation of uncertainty in runoff phenomenon based on comparisons between SDE (stochastic differential equation) and Fokker-Planck equation. The Fokker-Planck equation is a partial differential equation that describes the temporal variation of PDF (probability density function), and there is evidence to suggest that SDEs and Fokker-Planck equations are equivalent mathematically. In this paper, therefore, the uncertainty of discharge on the uncertainty of rainfall is explained theoretically and mathematically by introduction of theory of stochastic process. The lumped rainfall-runoff model is represented by SDE (stochastic differential equation) due to describe it as difference formula, because the temporal variation of rainfall is expressed by its average plus deviation, which is approximated by Gaussian distribution. This is attributed to the observed rainfall by rain-gauge station and radar rain-gauge system. As a result, this paper has shown that it is possible to evaluate the uncertainty of discharge by using the relationship between SDE (stochastic differential equation) and Fokker-Planck equation. Moreover, the results of this study show that the uncertainty of discharge increases as rainfall intensity rises and non-linearity about resistance grows strong. These results are clarified by PDFs (probability density function) that satisfy Fokker-Planck equation about discharge. It means the reasonable discharge can be

  11. Modeling water table fluctuations by means of a stochastic differential equation

    NASA Astrophysics Data System (ADS)

    Bierkens, Marc F. P.

    1998-10-01

    The combined system of soil-water and shallow groundwater is modeled with simple mass balance equations assuming equilibrium soil moisture conditions. This results in an ordinary but nonlinear differential equation of water table depth at a single location. If errors in model inputs, errors due to model assumptions and parameter uncertainty are lumped and modeled as a wide band noise process, a stochastic differential equation (SDE) results. A solution for the stationary probability density function is given through use of the Fokker-Planck equation. For the nonstationary case, where the model inputs are given as daily time series, sample functions of water table depth, soil saturation, and drainage discharge can be simulated by numerically solving the SDE. These sample functions can be used for designing drainage systems and to perform risk analyses. The parameters and noise statistics of the SDE are calibrated on time series of water table depths by embedding the SDE in a Kaiman filter algorithm and using the filter innovations in a filter-type maximum likelihood criterion. The stochastic model is calibrated and validated at two locations: a peat soil with a very shallow water table and a loamy sand soil with a moderately shallow water table. It is shown in both cases that sample functions simulated with the SDE are able to reproduce a wide range of statistics of water table depth. Despite its unrealistic assumption of constant inputs, the stationary solution derived from the Fokker-Planck equation gives good results for the peat soil, most likely because the characteristic response time of the water table is very small.

  12. Time of feeding and possible associated thermoregulatory benefits in bronze mannikins Lonchura cucullata.

    PubMed

    Seagram, R; Adams, N; Slotow, R

    2001-11-01

    Birds with a small body size have a high surface area to volume ratio, and this means that they have a high rate of heat loss to the environment. Birds may employ behavioural strategies in order to counter this heat loss. The adjustment of feeding patterns in the short term is probably the least documented of all of these strategies. Feeding results in the specific dynamic effect (SDE) which increases the metabolic rate of animals after a feeding bout. This increase in metabolic rate has been reported to possibly substitute for thermoregulatory costs in a variety of endotherms, including house wrens (Troglodytes aedon) and a variety of finch species. The thermoneutral zone was described for bronze mannikins, Lonchura cucullata (T(lc)=33.7 degrees C), and the bronze mannikins' post-absorptive physiology was described within this thermoneutral zone. Bronze mannikin mean basal metabolic rate (0.043+/-0.0038 S.E. ml O(2) min(-1) g(-1)), daytime resting metabolic rates (0.0549+/-0.0088 S.E. ml O(2) min(-1) g(-1)), and diurnal metabolic responses were described. The SDE in bronze mannikins was demonstrated within the thermoneutral zone, and was quantified. The mean magnitude of the SDE was 26.42% of mean total metabolism of post-absorptive birds. The magnitude of this SDE was independent of meal size and bird body mass. Assuming a 100% substitution, the presence of the SDE may afford bronze mannikins a maximum thermoregulatory energy saving of approximately 71.76 J g(-1) over a 300-min period.

  13. Mechanism of subdural effusion evolves into chronic subdural hematoma: IL-8 inducing neutrophil oxidative burst.

    PubMed

    Tao, Zhiqiang; Lin, Yingying; Hu, Maotong; Ding, Shenghong; Li, Jianwei; Qiu, Yongming

    2016-01-01

    Chronic subdural hematoma (CSDH) is still a mysterious disease. Though great success has been has achieved by neuro-surgery treatment, the origin and development of CSDH remains unknown. Tremendous clinical observations have found the correlation of subdural effusion (SDE) and CSDH. However, systematic elucidation of CSDH's origin and progression is lacking while almost all the current hypothesis only explained partial phenomenon. This hypothesis proposes Interleukin (IL)-8 inducing neutrophil respiratory burst is the crucial impact when SDE evolves into CSDH. IL-8 initially secreted by dural border layer cells, accumulates and the concentration of IL-8 rises in the SDE cavity. Accompanied by the formation of neo-membrane under the dura meninges, IL-8 firstly prompts to establish the neo-vasculature in it, and then attracts lymphocytes aggregation in the neo-membrane. Both the newly recruited lymphocytes and endothelial cells assist the further elevation of local IL-8 concentration. When the IL-8 concentration elevated to a particular level, it attracts neutrophils to the inner wall of neo-vessels and primes them to oxidative burst. Lysosomes and superoxide released by these neutrophils make the fragile neo-capillary became leaky, and subsequently the plasma and blood cells run into SDE. However, as long as the erythrocytes come into the cavity, they shall bind large quantity of IL-8 and decrease IL-8 concentration to a lower level relatively that reduce the neutrophils recruit. When this negative feedback is stagnancy, for example, the SDE space is so large in elder man who is experiencing brain atrophy, the neo-vessels have to release more erythrocytes to bind IL-8, the liquid cavity will expand and the high intracranial pressure symptoms appeared. Our hypothesis holds potential for the proper therapeutic intervention of CSDH. IL-8 antagonist and other anti-inflammation drugs like macrolides antibiotics, glucocorticoid and atorvastatin might be optional to resist

  14. FISCAL YEAR 2006 REPORT ON ELECTROLYZER COMPONENT DEVELOPMENT FOR THE HYBRID SULFUR PROJECT

    SciTech Connect

    Colon-Mercado, H; David Hobbs, D; Daryl Coleman, D; Amy Ekechukwu, A

    2006-08-03

    Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. In FY05, testing at the Savannah River National Laboratory (SRNL) explored a low temperature fuel cell design concept for the SDE. The advantages of this design concept include high electrochemical efficiency and small volumetric footprint that is crucial for successful implementation on a commercial scale. A key component of the SDE is the ion conductive membrane through which protons produced at anode migrate to the cathode and react to produce hydrogen. An ideal membrane for the SDE should have both low ionic resistivity and low sulfur dioxide transport. These features allow the electrolyzer to perform at high currents with low potentials, along with preventing contamination of both the hydrogen output and poisoning of the catalysts involved. Another key component is the electrocatalyst material used for the anode and cathode. Good electrocatalysts should be chemically stable and low overpotential for the desired electrochemical reactions. This report summarizes results from activities to evaluate different membrane and electrocatalyst materials for the SDE. Several different types of commercially-available membranes were analyzed for ionic resistance and sulfur dioxide transport including perfluorinated sulfonic acid, sulfonated poly-etherketone-ketone, and poly-benzimidazole membranes. Of these membrane types, the poly-benzimidazole (PBI) membrane, Celtec-L, exhibited the best combination of characteristics for use in an SDE. Testing examined the activity and stability of platinum and palladium as electrocatalyst for the SDE in sulfuric acid solutions. Cyclic and linear sweep voltammetry revealed that platinum provided better catalytic activity with much lower potentials and higher currents than palladium

  15. Stochastic models for the Trojan Y-Chromosome eradication strategy of an invasive species.

    PubMed

    Wang, Xueying; Walton, Jay R; Parshad, Rana D

    2016-01-01

    The Trojan Y-Chromosome (TYC) strategy, an autocidal genetic biocontrol method, has been proposed to eliminate invasive alien species. In this work, we develop a Markov jump process model for this strategy, and we verify that there is a positive probability for wild-type females going extinct within a finite time. Moreover, when sex-reversed Trojan females are introduced at a constant population size, we formulate a stochastic differential equation (SDE) model as an approximation to the proposed Markov jump process model. Using the SDE model, we investigate the probability distribution and expectation of the extinction time of wild-type females by solving Kolmogorov equations associated with these statistics. The results indicate how the probability distribution and expectation of the extinction time are shaped by the initial conditions and the model parameters.

  16. Modeling of long-range memory processes with inverse cubic distributions by the nonlinear stochastic differential equations

    NASA Astrophysics Data System (ADS)

    Kaulakys, B.; Alaburda, M.; Ruseckas, J.

    2016-05-01

    A well-known fact in the financial markets is the so-called ‘inverse cubic law’ of the cumulative distributions of the long-range memory fluctuations of market indicators such as a number of events of trades, trading volume and the logarithmic price change. We propose the nonlinear stochastic differential equation (SDE) giving both the power-law behavior of the power spectral density and the long-range dependent inverse cubic law of the cumulative distribution. This is achieved using the suggestion that when the market evolves from calm to violent behavior there is a decrease of the delay time of multiplicative feedback of the system in comparison to the driving noise correlation time. This results in a transition from the Itô to the Stratonovich sense of the SDE and yields a long-range memory process.

  17. A Hitch-hiker's Guide to Stochastic Differential Equations - Solution Methods for Energetic Particle Transport in Space Physics and Astrophysics

    NASA Astrophysics Data System (ADS)

    Strauss, R. Du Toit; Effenberger, Frederic

    2017-03-01

    In this review, an overview of the recent history of stochastic differential equations (SDEs) in application to particle transport problems in space physics and astrophysics is given. The aim is to present a helpful working guide to the literature and at the same time introduce key principles of the SDE approach via "toy models". Using these examples, we hope to provide an easy way for newcomers to the field to use such methods in their own research. Aspects covered are the solar modulation of cosmic rays, diffusive shock acceleration, galactic cosmic ray propagation and solar energetic particle transport. We believe that the SDE method, due to its simplicity and computational efficiency on modern computer architectures, will be of significant relevance in energetic particle studies in the years to come.

  18. Impression management and achievement motivation: Investigating substantive links.

    PubMed

    Elliot, Andrew J; Aldhobaiban, Nawal; Murayama, Kou; Kobeisy, Ahmed; Gocłowska, Małgorzata A; Khyat, Aber

    2016-01-24

    In this research, we investigate impression management (IM) as a substantive personality variable by linking it to differentiated achievement motivation constructs, namely achievement motives (workmastery, competitiveness, fear of failure) and achievement goals (mastery-approach, mastery-avoidance, performance-approach, performance-avoidance). Study 1 revealed that IM was a positive predictor of workmastery and a negative predictor of competitiveness (with and without self-deceptive enhancement (SDE) controlled). Studies 2a and 2b revealed that IM was a positive predictor of mastery-approach goals and mastery-avoidance goals (without and, in Study 2b, with SDE controlled). These findings highlight the value of conceptualising and utilising IM as a personality variable in its own right and shed light on the nature of the achievement motive and achievement goal constructs.

  19. Aroma quality assessment of Korean fermented red pepper paste (gochujang) by aroma extract dilution analysis and headspace solid-phase microextraction-gas chromatography-olfactometry.

    PubMed

    Kang, Kyung-Mo; Baek, Hyung-Hee

    2014-02-15

    The objective of this study was to assess aroma quality of gochujang using purge and trap, simultaneous steam distillation and solvent extraction (SDE), and headspace solid-phase microextraction (HS-SPME), followed by gas chromatography-olfactometry (GC-O). Nineteen and 28 aroma-active compounds were detected by aroma extract dilution analysis of purge and trap and SDE, respectively. Diallyl disulfide and 3-isobutyl-2-methoxypyrazine played a significant role in the aroma quality of gochujang. Twelve aroma-active compounds were detected by HS-SPME-GC-O based on sample dilution analysis. Methional, diallyl disulfide, and 3-isobutyl-2-methoxypyrazine were the most intense aroma-active compounds. 3-Isobutyl-2-methoxypyrazine was identified for the first time in gochujang.

  20. Effect of drying method on the volatiles in bay leaf (Laurus nobilis L.).

    PubMed

    Díaz-Maroto, M Consuelo; Pérez-Coello, M Soledad; Cabezudo, M Dolores

    2002-07-31

    The effect of different drying treatments on the volatiles in bay leaf (Laurus nobilis L.) was studied. Simultaneous distillation extraction (SDE) and solid-phase microextraction (SPME) were compared by gas chromatography-mass spectrometry (GC-MS) of the volatile components in bay leaves. SDE yielded better quantitative analysis results. Four drying treatments were employed: air-drying at ambient temperature, oven-drying at 45 degrees C, freezing, and freeze-drying. Oven drying at 45 degrees C and air-drying at ambient temperature produced quite similar results and caused hardly any loss in volatiles as compared to the fresh herb, whereas freezing and freeze-drying brought about substantial losses in bay leaf aroma and led to increases in the concentration levels of certain components, e.g., eugenol, elemicin, spathulenol, and beta-eudesmol.

  1. Data-driven approach to decomposing complex enzyme kinetics with surrogate models.

    PubMed

    Calderon, Christopher P

    2009-12-01

    The temporal autocorrelation (AC) function associated with monitoring order parameters characterizing conformational fluctuations of an enzyme is analyzed using a collection of surrogate models. The surrogates considered are phenomenological stochastic differential equation (SDE) models. It is demonstrated how an ensemble of such surrogate models, each surrogate being calibrated from a single trajectory, indirectly contains information about unresolved conformational degrees of freedom. This ensemble can be used to construct complex temporal ACs associated with a "non-Markovian" process. The ensemble of surrogates approach allows researchers to consider models more flexible than a mixture of exponentials to describe relaxation times and at the same time gain physical information about the system. The relevance of this type of analysis to matching single-molecule experiments to computer simulations and how more complex stochastic processes can emerge from a mixture of simpler processes is also discussed. The ideas are illustrated on a toy SDE model and on molecular-dynamics simulations of the enzyme dihydrofolate reductase.

  2. Characterization of Microgravity Environment on Mir

    NASA Technical Reports Server (NTRS)

    Kim, Hyoung; Kaouk, Mohamed

    2000-01-01

    This paper presents the microgravity analysis results using dynamic response data collected during the first phase of the Mir Structural Dynamics Experiment (MiSDE). Although MiSDE was designed and performed to verify structural dynamic models, it also provided information for determining microgravity characteristics of the structure. This study analyzed ambient responses acquired during orbital day-to-night and night-to-day transitions, crew treadmill and ergometer exercises, and intentional crew activities. Acceleration levels for one-third octave bands were calculated to characterize the microgravity environment of the station. Spectrograms were also used to analyze the time transient nature of the responses. Detailed theoretical background and analysis results will also be included in the final draft.

  3. Option pricing during post-crash relaxation times

    NASA Astrophysics Data System (ADS)

    Dibeh, Ghassan; Harmanani, Haidar M.

    2007-07-01

    This paper presents a model for option pricing in markets that experience financial crashes. The stochastic differential equation (SDE) of stock price dynamics is coupled to a post-crash market index. The resultant SDE is shown to have stock price and time dependent volatility. The partial differential equation (PDE) for call prices is derived using risk-neutral pricing. European call prices are then estimated using Monte Carlo and finite difference methods. Results of the model show that call option prices after the crash are systematically less than those predicted by the Black-Scholes model. This is a result of the effect of non-constant volatility of the model that causes a volatility skew.

  4. Stochastic dynamic models and Chebyshev splines

    PubMed Central

    Fan, Ruzong; Zhu, Bin; Wang, Yuedong

    2015-01-01

    In this article, we establish a connection between a stochastic dynamic model (SDM) driven by a linear stochastic differential equation (SDE) and a Chebyshev spline, which enables researchers to borrow strength across fields both theoretically and numerically. We construct a differential operator for the penalty function and develop a reproducing kernel Hilbert space (RKHS) induced by the SDM and the Chebyshev spline. The general form of the linear SDE allows us to extend the well-known connection between an integrated Brownian motion and a polynomial spline to a connection between more complex diffusion processes and Chebyshev splines. One interesting special case is connection between an integrated Ornstein–Uhlenbeck process and an exponential spline. We use two real data sets to illustrate the integrated Ornstein–Uhlenbeck process model and exponential spline model and show their estimates are almost identical. PMID:26045632

  5. A shared data environment for the Military Traffic Management Command Directorate of International Traffic

    SciTech Connect

    Russell, D.L.; Wheeler, V.V. ); Truett, L.F. )

    1992-01-01

    In September 1991, Oak Ridge National Laboratory (ORNL) completed tasking to assist the Military Traffic Management Command Directorate of International Traffic (MTIT) in the analysis of a potential Shared Data Environment (SDE) for MTIT automated cargo traffic systems. This analysis was a preliminary effort with emphasis on documentation of requirements, examination of design alternatives, and identification of specific MTIT systems' data sharing problems. This report records the results of the ORNL analysis. The SDE envisioned by ORNL at this point in the analysis is not merely a repository of information; it is also a system that allows processing of distributed data. To provide high-level access to and control over international cargo processes, ORNL recommends a loosely coupled, replicated database design with high-speed communications among all sites.

  6. A shared data environment for the Military Traffic Management Command Directorate of International Traffic

    SciTech Connect

    Russell, D.L.; Wheeler, V.V.; Truett, L.F.

    1992-01-01

    In September 1991, Oak Ridge National Laboratory (ORNL) completed tasking to assist the Military Traffic Management Command Directorate of International Traffic (MTIT) in the analysis of a potential Shared Data Environment (SDE) for MTIT automated cargo traffic systems. This analysis was a preliminary effort with emphasis on documentation of requirements, examination of design alternatives, and identification of specific MTIT systems` data sharing problems. This report records the results of the ORNL analysis. The SDE envisioned by ORNL at this point in the analysis is not merely a repository of information; it is also a system that allows processing of distributed data. To provide high-level access to and control over international cargo processes, ORNL recommends a loosely coupled, replicated database design with high-speed communications among all sites.

  7. 12-Digit Watershed Boundary Data 1:24,000 for EPA Region 2 and Surrounding States (NAT_HYDROLOGY.HUC12_NRCS_REG2)

    EPA Pesticide Factsheets

    12 digit Hydrologic Units (HUCs) for EPA Region 2 and surrounding states (Northeastern states, parts of the Great Lakes, Puerto Rico and the USVI) downloaded from the Natural Resources Conservation Service (NRCS) Geospatial Gateway and imported into the EPA Region 2 Oracle/SDE database. This layer reflects 2009 updates to the national Watershed Boundary Database (WBD) that included new boundary data for New York and New Jersey.

  8. Stochastic differential equation model for linear growth birth and death processes with immigration and emigration

    NASA Astrophysics Data System (ADS)

    Granita, Bahar, A.

    2015-03-01

    This paper discusses on linear birth and death with immigration and emigration (BIDE) process to stochastic differential equation (SDE) model. Forward Kolmogorov equation in continuous time Markov chain (CTMC) with a central-difference approximation was used to find Fokker-Planckequation corresponding to a diffusion process having the stochastic differential equation of BIDE process. The exact solution, mean and variance function of BIDE process was found.

  9. Stochastic differential equation models for ion channel noise in Hodgkin-Huxley neurons.

    PubMed

    Goldwyn, Joshua H; Imennov, Nikita S; Famulare, Michael; Shea-Brown, Eric

    2011-04-01

    The random transitions of ion channels between conducting and nonconducting states generate a source of internal fluctuations in a neuron, known as channel noise. The standard method for modeling the states of ion channels nonlinearly couples continuous-time Markov chains to a differential equation for voltage. Beginning with the work of R. F. Fox and Y.-N. Lu [Phys. Rev. E 49, 3421 (1994)], there have been attempts to generate simpler models that use stochastic differential equation (SDEs) to approximate the stochastic spiking activity produced by Markov chain models. Recent numerical investigations, however, have raised doubts that SDE models can capture the stochastic dynamics of Markov chain models.We analyze three SDE models that have been proposed as approximations to the Markov chain model: one that describes the states of the ion channels and two that describe the states of the ion channel subunits. We show that the former channel-based approach can capture the distribution of channel noise and its effects on spiking in a Hodgkin-Huxley neuron model to a degree not previously demonstrated, but the latter two subunit-based approaches cannot. Our analysis provides intuitive and mathematical explanations for why this is the case. The temporal correlation in the channel noise is determined by the combinatorics of bundling subunits into channels, but the subunit-based approaches do not correctly account for this structure. Our study confirms and elucidates the findings of previous numerical investigations of subunit-based SDE models. Moreover, it presents evidence that Markov chain models of the nonlinear, stochastic dynamics of neural membranes can be accurately approximated by SDEs. This finding opens a door to future modeling work using SDE techniques to further illuminate the effects of ion channel fluctuations on electrically active cells.

  10. Proof Checking the RSA (Rivest, Shamir and Adleman) Public Key Encryption Algorithm.

    DTIC Science & Technology

    1982-09-01

    Fermat’s theorem, number theory , pigeon hole principle. 20. ABSTRACT (Continue an reverse sde it neceeseand Ideify by block nu mbe r) The authors...of integers modulo (p-1)*(q-1). .. Among the lemmas proved mechanically and used in the ma _Aroof are many familia theorems of number theory ...the ring of integers modulo (p-1)*(q-1). Among the lemmas proved mechanically and used in the main proof are many familiar theorems of number theory

  11. Final Report for project titled "New fluoroionomer electrolytes with high conductivity and low SO2 crossover for use in electrolyzers being developed for hydrogen production from nuclear power plants"

    SciTech Connect

    Dennis W. Smith; Stephen Creager

    2012-09-13

    Thermochemical water splitting cycles, using the heat of nuclear power plants, offer an alternate highly efficient route for the production of hydrogen. Among the many possible thermochemical cycles for the hydrogen production, the sulfur-based cycles lead the competition in overall energy efficiency. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process, which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce hydrogen. The Savannah River National Laboratory (SRNL) selected the fuel cell MEA design concept for the SDE in the HyS process since the MEA concept provides a much smaller cell footprint than conventional parallel plate technology. The electrolyzer oxidizes sulfur dioxide to form sulfuric acid at the anode and reduces protons to form hydrogen at the cathode. The overall electrochemical cell reaction consists of the production of H{sub 2}SO{sub 4} and H{sub 2}. There is a significant need to provide the membrane materials that exhibit reduced sulfur dioxide transport characteristics without sacrificing other important properties such as high ionic conductivity and excellent chemical stability in highly concentrated sulfuric acid solutions saturated with sulfur dioxide. As an alternative membrane, sulfonated Perfluorocyclobutyl aromatic ether polymer (sPFCB) were expected to posses low SO2 permeability due to their stiff backbones as well as high proton conductivity, improved mechanical properties. The major accomplishments of this project were the synthesis, characterizations, and optimizations of suitable electrolyzers for good SDE performance and higher chemical stability against sulfuric acid. SDE performance results of developed sPFCB polyelectrolytes have shown that these membranes exhibit good chemical stability against H{sub 2}SO{sub 4}.

  12. Evolution equations for the joint probability of several compositions in turbulent combustion

    SciTech Connect

    Bakosi, Jozsef

    2010-01-01

    One-point statistical simulations of turbulent combustion require models to represent the molecular mixing of species mass fractions, which then determine the reaction rates. For multi-species mixing the Dirichlet distribution has been used to characterize the assumed joint probability density function (PDF) of several scalars, parametrized by solving modeled evolution equations for their means and the sum of their variances. The PDF is then used to represent the mixing state and to obtain the chemical reactions source terms in moment closures or large eddy simulation. We extend the Dirichlet PDF approach to transported PDF methods by developing its governing stochastic differential equation (SDE). The transport equation, as opposed to parametrizing the assumed PDF, enables (1) the direct numerical computation of the joint PDF (and therefore the mixing model to directly account for the flow dynamics (e.g. reaction) on the shape of the evolving PDF), and (2) the individual specification of the mixing timescales of each species. From the SDE, systems of equations are derived that govern the first two moments, based on which constraints are established that provide consistency conditions for material mixing. A SDE whose solution is the generalized Dirichlet PDF is also developed and some of its properties from the viewpoint of material mixing are investigated. The generalized Dirichlet distribution has the following advantages over the standard Dirichlet distribution due to its more general covariance structure: (1) its ability to represent differential diffusion (i.e. skewness) without affecting the scalar means, and (2) it can represent both negatively and positively correlated scalars. The resulting development is a useful representation of the joint PDF of inert or reactive scalars in turbulent flows: (1) In moment closures, the mixing physics can be consistently represented by one underlying modeling principle, the Dirichlet or the generalized Dirichlet PDF, and

  13. The Revenge of Europe: NATO and the Transatlantic Relationship in the Era of the European Union (Walker Paper, Number 2)

    DTIC Science & Technology

    2005-09-01

    Air Force Fellows supports a post -SDE military fellow at the Council on Foreign Relations. On the intermediate developmental education level, the chief...states.40 Where once stood drop-arm barriers, guard posts , and inter- minable passport-control lines, now stands . . . nothing. A trip from Lyon to...another. Anarchy is, therefore, a self-help system, and it is pitiless. States must learn to take care of themselves, or they will perish. Repelled by

  14. Data Management of Watershed Information and Data Enterprise Repository Implementation at Fort Hood, Texas

    DTIC Science & Technology

    2003-03-01

    9i database • GIS datasets in ArcGIS Geodatabase • CADD data • Metadata • ESRI GIS Product Install (Desktop) • ArcSDE DPW-WEB • MS Internet...official Department of the Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN IT IS NO LONGER NEEDED. DO NOT...implementation of the Data Enterprise Repository (DER). The DER was an Enterprise Geographic Information System designed to house GIS data

  15. Hybrid sulfur cycle operation for high-temperature gas-cooled reactors

    DOEpatents

    Gorensek, Maximilian B

    2015-02-17

    A hybrid sulfur (HyS) cycle process for the production of hydrogen is provided. The process uses a proton exchange membrane (PEM) SO.sub.2-depolarized electrolyzer (SDE) for the low-temperature, electrochemical reaction step and a bayonet reactor for the high-temperature decomposition step The process can be operated at lower temperature and pressure ranges while still providing an overall energy efficient cycle process.

  16. Functional characterization of the Aspergillus nidulans glucosylceramide pathway reveals that LCB Δ8-desaturation and C9-methylation are relevant to filamentous growth, lipid raft localization and Psd1 defensin activity.

    PubMed

    Fernandes, C M; de Castro, P A; Singh, A; Fonseca, F L; Pereira, M D; Vila, T V M; Atella, G C; Rozental, S; Savoldi, M; Del Poeta, M; Goldman, G H; Kurtenbach, E

    2016-11-01

    C8-desaturated and C9-methylated glucosylceramide (GlcCer) is a fungal-specific sphingolipid that plays an important role in the growth and virulence of many species. In this work, we investigated the contribution of Aspergillus nidulans sphingolipid Δ8-desaturase (SdeA), sphingolipid C9-methyltransferases (SmtA/SmtB) and glucosylceramide synthase (GcsA) to fungal phenotypes, sensitivity to Psd1 defensin and Galleria mellonella virulence. We showed that ΔsdeA accumulated C8-saturated and unmethylated GlcCer, while gcsA deletion impaired GlcCer synthesis. Although increased levels of unmethylated GlcCer were observed in smtA and smtB mutants, ΔsmtA and wild-type cells showed a similar 9,Me-GlcCer content, reduced by 50% in the smtB disruptant. The compromised 9,Me-GlcCer production in the ΔsmtB strain was not accompanied by reduced filamentation or defects in cell polarity. When combined with the smtA deletion, smtB repression significantly increased unmethylated GlcCer levels and compromised filamentous growth. Furthermore, sdeA and gcsA mutants displayed growth defects and raft mislocalization, which were accompanied by reduced neutral lipids levels and attenuated G. mellonella virulence in the ΔgcsA strain. Finally, ΔsdeA and ΔgcsA showed increased resistance to Psd1, suggesting that GlcCer synthesis and fungal sphingoid base structure specificities are relevant not only to differentiation but also to proper recognition by this antifungal defensin.

  17. Enlightened Multiscale Simulation of Biochemical Networks. Core Theory, Validating Experiments, and Implementation in Open Software

    DTIC Science & Technology

    2006-10-01

    and 2) supported SBML use and evolution (direct support for DARPA Bio- SPICE ). 15. SUBJECT TERMS systems biology, simulation, robustness, markup...Signaling in Yeast . . . . . . 41 3.1.4 Optimization-Based Methods for System Verification . . . . . . . . . . . . . . 44 3.1.5 Stochastic Simulation...computations and was not based on numerous simulations of the corresponding SDE. 3.1.3 Model Validation/Invalidation for the G-Protein Signaling in Yeast

  18. Stochastic differential equation model for linear growth birth and death processes with immigration and emigration

    SciTech Connect

    Granita; Bahar, A.

    2015-03-09

    This paper discusses on linear birth and death with immigration and emigration (BIDE) process to stochastic differential equation (SDE) model. Forward Kolmogorov equation in continuous time Markov chain (CTMC) with a central-difference approximation was used to find Fokker-Planckequation corresponding to a diffusion process having the stochastic differential equation of BIDE process. The exact solution, mean and variance function of BIDE process was found.

  19. UHF Radiowave Propagation through Forests

    DTIC Science & Technology

    1982-09-01

    sde It nece sary and Identify b block number) " A model for UHF radiowave propagation thzough a forest of tree trunks, branches, and leaves is...all having prescribed location and orientation statistics. Tree trunks are modelled as infinitely-long, circular, lossy-di- electric cylinders...results. An anisotropic half-space model of the forest is developed based upon the effective dyadic susceptibility and the direct-, reflected-, and

  20. Worldwide Buoy Technology Survey. Volume 1. Report

    DTIC Science & Technology

    1991-02-01

    the KethelandA, are described In Appendix E. I SDe to the voluminous nature of Appendices 0 and C , they are pteanted. in separately bound volums...N.S.) is studying the use of composite materials for buoy construction under a CCG contract. This study will, according to CCG, be completed by the ... materials considered for the body of this buoy were stainless steel and reinforced plastics. The former was found to be too expensive and the

  1. Schwinger-Dyson Equations and Dynamical gluon mass generation

    SciTech Connect

    Aguilar, A.C.; Natale, A.A.

    2004-12-02

    We obtain a solution for the gluon propagador in Landau gauge within two distinct approximations for the Schwinger-Dyson equations (SDE). The first, named Mandelstam's approximation, consist in neglecting all contributions that come from fermions and ghosts fields while in the second, the ghosts fields are taken into account leading to a coupled system of integral equations. In both cases we show that a dynamical mass for the gluon propagator can arise as a solution.

  2. Real time programming environment for Windows, Appendix A

    SciTech Connect

    1998-04-05

    This appendix contains all source code for the RTProE system. The following file contents are included: pdb.h; hgen.l; hgen.y; igen.l; igen.y; pdm.l; pdm.y; rtdata.l; rtdata.y; framegen.c; librt.c; librt.h; rtsched.c; build.tsh; sde.tcl; rtsched.def.

  3. Lipopolysaccharide and β-1,3-glucan-binding protein (LGBP) bind to seaweed polysaccharides and activate the prophenoloxidase system in white shrimp Litopenaeus vannamei.

    PubMed

    Chen, Yu-Yuan; Chen, Jiann-Chu; Kuo, Yi-Hsuan; Lin, Yong-Chin; Chang, Yu-Hsuan; Gong, Hong-Yi; Huang, Chien-Lun

    2016-02-01

    Lipopolysaccharide and β-1,3-glucan-binding protein (LGBP), important pattern recognition proteins (PRPs), recognize lipopolysaccharide (LPS) and β-1,3-glucan (βG), known as pathogen-associated molecular patterns (PAMPs), and subsequently trigger innate immunity. Several seaweed polysaccharides and seaweed extracts increase immune parameters and resistance to pathogens. Here, we constructed the expression vector pET28b-LvLGBP and transferred it into Escherichia coli BL21 (DE3) for protein expression and to produce the recombinant protein LGBP (rLvLGBP) in white shrimp Litopenaeus vannamei. We examined the binding of rLvLGBP with seaweed-derived polysaccharides including alginate, carrageenan, fucoidan, laminarin, Gracilaria tenuistipitata extract (GTE), and Sargassum duplicatum extract (SDE), and examined the phenoloxidase activity of shrimp haemocytes incubated with a mixture of rLvLGBP and each polysaccharide. We also examined the binding of rLvLGBP with LPS and βG, and the phenoloxidase activity of shrimp haemocytes incubated with a mixture of rLvLGBP and LPS (rLvLGBP-LPS) or a mixture of rLvLGBP and βG (rLvLGBP-βG). An ELISA binding assay indicated that rLvLGBP binds to LPS, βG, alginate, carrageenan, fucoidan, laminarin, GTE, and SDE with dissociation constants of 0.1138-0.1770 μM. Furthermore, our results also indicated that the phenoloxidase activity of shrimp haemocytes incubated with a mixture of rLvLGBP and LPS, βG, alginate, carrageenan, fucoidan, laminarin, GTE, and SDE significantly increased by 328%, 172%, 200%, 213%, 197%, 194%, 191%, and 197%, respectively compared to controls (cacodylate buffer). We conclude that LvLGBP functions as a PRP, recognizes and binds to LPS, βG, alginate, carrageenan, fucoidan, laminarin, GTE, and SDE, and subsequently leads to activating innate immunity in shrimp.

  4. Simulation Tools for Digital LSI (Large Scale Integration) Design.

    DTIC Science & Technology

    1983-09-01

    potential paths e:,,t from a t.,sde to t alnd (,A I isl gc’, , that It iioht he coton ilci, ilt d I:eriniiie d f ’ Ti.. ’he o diti ns for %0l’h , i p th...the flag is set during an execution of the code, another iteration is performed; otherwise, the subroutine is finished . The following is an extended

  5. Stochastic nonlinear mixed effects: a metformin case study.

    PubMed

    Matzuka, Brett; Chittenden, Jason; Monteleone, Jonathan; Tran, Hien

    2016-02-01

    In nonlinear mixed effect (NLME) modeling, the intra-individual variability is a collection of errors due to assay sensitivity, dosing, sampling, as well as model misspecification. Utilizing stochastic differential equations (SDE) within the NLME framework allows the decoupling of the measurement errors from the model misspecification. This leads the SDE approach to be a novel tool for model refinement. Using Metformin clinical pharmacokinetic (PK) data, the process of model development through the use of SDEs in population PK modeling was done to study the dynamics of absorption rate. A base model was constructed and then refined by using the system noise terms of the SDEs to track model parameters and model misspecification. This provides the unique advantage of making no underlying assumptions about the structural model for the absorption process while quantifying insufficiencies in the current model. This article focuses on implementing the extended Kalman filter and unscented Kalman filter in an NLME framework for parameter estimation and model development, comparing the methodologies, and illustrating their challenges and utility. The Kalman filter algorithms were successfully implemented in NLME models using MATLAB with run time differences between the ODE and SDE methods comparable to the differences found by Kakhi for their stochastic deconvolution.

  6. RECENT ADVANCES IN THE DEVELOPMENT OF THE HYBRID SULFUR PROCESS FOR HYDROGEN PRODUCTION

    SciTech Connect

    Hobbs, D.

    2010-07-22

    Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process, which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. In the HyS Process, sulfur dioxide is oxidized in the presence of water at the electrolyzer anode to produce sulfuric acid and protons. The protons are transported through a cation-exchange membrane electrolyte to the cathode and are reduced to form hydrogen. In the second stage of the process, the sulfuric acid by-product from the electrolyzer is thermally decomposed at high temperature to produce sulfur dioxide and oxygen. The two gases are separated and the sulfur dioxide recycled to the electrolyzer for oxidation. The Savannah River National Laboratory (SRNL) has been exploring a fuel-cell design concept for the SDE using an anolyte feed comprised of concentrated sulfuric acid saturated with sulfur dioxide. The advantages of this design concept include high electrochemical efficiency and small footprint compared to a parallel-plate electrolyzer design. This paper will provide a summary of recent advances in the development of the SDE for the HyS process.

  7. Real time heart rate variability assessment from Android smartphone camera photoplethysmography: Postural and device influences.

    PubMed

    Guede-Fernandez, F; Ferrer-Mileo, V; Ramos-Castro, J; Fernandez-Chimeno, M; Garcia-Gonzalez, M A

    2015-01-01

    The aim of this paper is to present a smartphone based system for real-time pulse-to-pulse (PP) interval time series acquisition by frame-to-frame camera image processing. The developed smartphone application acquires image frames from built-in rear-camera at the maximum available rate (30 Hz) and the smartphone GPU has been used by Renderscript API for high performance frame-by-frame image acquisition and computing in order to obtain PPG signal and PP interval time series. The relative error of mean heart rate is negligible. In addition, measurement posture and the employed smartphone model influences on the beat-to-beat error measurement of heart rate and HRV indices have been analyzed. Then, the standard deviation of the beat-to-beat error (SDE) was 7.81 ± 3.81 ms in the worst case. Furthermore, in supine measurement posture, significant device influence on the SDE has been found and the SDE is lower with Samsung S5 than Motorola X. This study can be applied to analyze the reliability of different smartphone models for HRV assessment from real-time Android camera frames processing.

  8. Simultaneous Distillation Extraction of Some Volatile Flavor Components from Pu-erh Tea Samples-Comparison with Steam Distillation-Liquid/Liquid Extraction and Soxhlet Extraction.

    PubMed

    Gu, Xungang; Zhang, Zhengzhu; Wan, Xiaochun; Ning, Jingming; Yao, Chengcheng; Shao, Wanfang

    2009-01-01

    A simutaneous distillation extraction (SDE) combined GC method was constructed for determination of volatile flavor components in Pu-erh tea samples. Dichloromethane and ethyl decylate was employed as organic phase in SDE and internal standard in determination, respectively. Weakly polar DB-5 column was used to separate the volatile flavor components in GC, 10 of the components were quantitatively analyzed, and further confirmed by GC-MS. The recovery covered from 66.4%-109%, and repeatability expressed as RSD was in range of 1.44%-12.6%. SDE was most suitable for the extraction of the anlytes by comparing with steam distillation-liquid/liquid extraction and Soxhlet extraction. Commercially available Pu-erh tea samples, including Pu-erh raw tea and ripe tea, were analyzed by the constructed method. the high-volatile components, such as benzyl alcohol, linalool oxide, and linalool, were greatly rich in Pu-erh raw teas, while the contents of 1,2,3-Trimethoxylbenzene and 1,2,4-Trimethoxylbenzene were much high in Pu-erh ripe teas.

  9. Demographic stochasticity reduces the synchronizing effect of dispersal in predator-prey metapopulations.

    PubMed

    Simonis, Joseph L

    2012-07-01

    Dispersal may affect predator-prey metapopulations by rescuing local sink populations from extinction or by synchronizing population dynamics across the metapopulation, increasing the risk of regional extinction. Dispersal is likely influenced by demographic stochasticity, however, particularly because dispersal rates are often very low in metapopulations. Yet the effects of demographic stochasticity on predator-prey metapopulations are not well known. To that end, I constructed three models of a two-patch predator-prey system. The models constitute a hierarchy of complexity, allowing direct comparisons. Two models included demographic stochasticity (pure jump process [PJP] and stochastic differential equations [SDE]), and the third was deterministic (ordinary differential equations [ODE]). One stochastic model (PJP) treated population sizes as discrete, while the other (SDE) allowed population sizes to change continuously. Both stochastic models only produced synchronized predator-prey dynamics when dispersal was high for both trophic levels. Frequent dispersal by only predators or prey in the PJP and SDE spatially decoupled the trophic interaction, reducing synchrony of the non-dispersive species. Conversely, the ODE generated synchronized predator-prey dynamics across all dispersal rates, except when initial conditions produced anti-phase transients. These results indicate that demographic stochasticity strongly reduces the synchronizing effect of dispersal, which is ironic because demographic stochasticity is often invoked post hoc as a driver of extinctions in synchronized metapopulations.

  10. Development and testing of a PEM SO2-depolarized electrolyzer and an operating method that prevents sulfur accumulation

    SciTech Connect

    Steimke, John L.; Steeper, Timothy J.; Colon-Mercado, Hector R.; Gorensek, Maximilian B.

    2015-09-02

    The hybrid sulfur (HyS) cycle is being developed as a technology to generate hydrogen by splitting water, using heat and electrical power from a nuclear or solar power plant. A key component is the SO2-depolarized electrolysis (SDE) cell, which reacts SO2 and water to form hydrogen and sulfuric acid. SDE could also be used in once-through operation to consume SO2 and generate hydrogen and sulfuric acid for sale. A proton exchange membrane (PEM) SDE cell based on a PEM fuel cell design was fabricated and tested. Measured cell potential as a function of anolyte pressure and flow rate, sulfuric acid concentration, and cell temperature are presented for this cell. Sulfur accumulation was observed inside the cell, which could have been a serious impediment to further development. A method to prevent sulfur formation was subsequently developed. As a result, this was made possible by a testing facility that allowed unattended operation for extended periods.

  11. Does human presynaptic striatal dopamine function predict social conformity?

    PubMed

    Stokes, Paul R A; Benecke, Aaf; Puraite, Julita; Bloomfield, Michael A P; Shotbolt, Paul; Reeves, Suzanne J; Lingford-Hughes, Anne R; Howes, Oliver; Egerton, Alice

    2014-03-01

    Socially desirable responding (SDR) is a personality trait which reflects either a tendency to present oneself in an overly positive manner to others, consistent with social conformity (impression management (IM)), or the tendency to view one's own behaviour in an overly positive light (self-deceptive enhancement (SDE)). Neurochemical imaging studies report an inverse relationship between SDR and dorsal striatal dopamine D₂/₃ receptor availability. This may reflect an association between SDR and D₂/₃ receptor expression, synaptic dopamine levels or a combination of the two. In this study, we used a [¹⁸F]-DOPA positron emission tomography (PET) image database to investigate whether SDR is associated with presynaptic dopamine function. Striatal [¹⁸F]-DOPA uptake, (k(i)(cer), min⁻¹), was determined in two independent healthy participant cohorts (n=27 and 19), by Patlak analysis using a cerebellar reference region. SDR was assessed using the revised Eysenck Personality Questionnaire (EPQ-R) Lie scale, and IM and SDE were measured using the Paulhus Deception Scales. No significant associations were detected between Lie, SDE or IM scores and striatal [¹⁸F]-DOPA k(i)(cer). These results indicate that presynaptic striatal dopamine function is not associated with social conformity and suggests that social conformity may be associated with striatal D₂/₃ receptor expression rather than with synaptic dopamine levels.

  12. Self-organized criticality as Witten-type topological field theory with spontaneously broken Becchi-Rouet-Stora-Tyutin symmetry

    SciTech Connect

    Ovchinnikov, Igor V.

    2011-05-15

    Here, a scenario is proposed, according to which a generic self-organized critical (SOC) system can be looked upon as a Witten-type topological field theory (W-TFT) with spontaneously broken Becchi-Rouet-Stora-Tyutin (BRST) symmetry. One of the conditions for the SOC is the slow driving noise, which unambiguously suggests Stratonovich interpretation of the corresponding stochastic differential equation (SDE). This, in turn, necessitates the use of Parisi-Sourlas-Wu stochastic quantization procedure, which straightforwardly leads to a model with BRST-exact action, i.e., to a W-TFT. In the parameter space of the SDE, there must exist full-dimensional regions where the BRST symmetry is spontaneously broken by instantons, which in the context of SOC are essentially avalanches. In these regions, the avalanche-type SOC dynamics is liberated from overwise a rightful dynamics-less W-TFT, and a Goldstone mode of Fadeev-Popov ghosts exists. Goldstinos represent moduli of instantons (avalanches) and being gapless are responsible for the critical avalanche distribution in the low-energy, long-wavelength limit. The above arguments are robust against moderate variations of the SDE's parameters and the criticality is 'self-tuned'. The proposition of this paper suggests that the machinery of W-TFTs may find its applications in many different areas of modern science studying various physical realizations of SOC. It also suggests that there may in principle exist a connection between some SOC's and the concept of topological quantum computing.

  13. The ISI distribution of the stochastic Hodgkin-Huxley neuron.

    PubMed

    Rowat, Peter F; Greenwood, Priscilla E

    2014-01-01

    The simulation of ion-channel noise has an important role in computational neuroscience. In recent years several approximate methods of carrying out this simulation have been published, based on stochastic differential equations, and all giving slightly different results. The obvious, and essential, question is: which method is the most accurate and which is most computationally efficient? Here we make a contribution to the answer. We compare interspike interval histograms from simulated data using four different approximate stochastic differential equation (SDE) models of the stochastic Hodgkin-Huxley neuron, as well as the exact Markov chain model simulated by the Gillespie algorithm. One of the recent SDE models is the same as the Kurtz approximation first published in 1978. All the models considered give similar ISI histograms over a wide range of deterministic and stochastic input. Three features of these histograms are an initial peak, followed by one or more bumps, and then an exponential tail. We explore how these features depend on deterministic input and on level of channel noise, and explain the results using the stochastic dynamics of the model. We conclude with a rough ranking of the four SDE models with respect to the similarity of their ISI histograms to the histogram of the exact Markov chain model.

  14. Identification of volatile compounds in codfish ( Gadus) by a combination of two extraction Methods coupled with GC-MS analysis

    NASA Astrophysics Data System (ADS)

    Chang, Yufei; Hou, Hu; Li, Bafang

    2016-06-01

    Codfish is a kind of abyssal fish species with a great value in food industry. However, the flavor of codfish, especially the unpleasant odor, has caused serious problems in its processing. To accurately identify the volatile compounds in codfish, a combination of solid phase micro-extraction (SPME) method and simultaneous distillation extraction (SDE) method was used to extract the volatiles. Gas chromatography-mass spectrometry (GC-MS) along with Kovats indices (KI) and authentic standard compounds were used to identify the volatiles. The results showed that a total of 86 volatile compounds were identified in codfish, of them 24 were extracted by SDE, 69 compounds by SPME, and 10 compounds by both SDE and SPME. Seventy volatile compounds were found to have specific odors, of them 7 typical compounds contributed significantly to the flavor of codfish. Alcohols ( i.e., (E)-2-penten-1-ol and 2-octanol), esters ( i.e., ethyl butyrate and methyl geranate), aldehydes ( i.e., 2-dodecenal and pentadecanal) contributed the most to fresh flavor while nitrogen compounds, sulphur compounds, furans, as well as some ketones ( i.e., 2-hydroxy-3-pentanone) brought unpleasant odor, such as fishy and earthy odor. It was indicated that the combination of multiple extraction methods and GC-MS analysis can enhance the accuracy of identification, and provide a reference for the further study on flavor of aquatic products.

  15. Development and testing of a PEM SO2-depolarized electrolyzer and an operating method that prevents sulfur accumulation

    DOE PAGES

    Steimke, John L.; Steeper, Timothy J.; Colon-Mercado, Hector R.; ...

    2015-09-02

    The hybrid sulfur (HyS) cycle is being developed as a technology to generate hydrogen by splitting water, using heat and electrical power from a nuclear or solar power plant. A key component is the SO2-depolarized electrolysis (SDE) cell, which reacts SO2 and water to form hydrogen and sulfuric acid. SDE could also be used in once-through operation to consume SO2 and generate hydrogen and sulfuric acid for sale. A proton exchange membrane (PEM) SDE cell based on a PEM fuel cell design was fabricated and tested. Measured cell potential as a function of anolyte pressure and flow rate, sulfuric acidmore » concentration, and cell temperature are presented for this cell. Sulfur accumulation was observed inside the cell, which could have been a serious impediment to further development. A method to prevent sulfur formation was subsequently developed. As a result, this was made possible by a testing facility that allowed unattended operation for extended periods.« less

  16. Strength Differential Measured in Inconel 718: Effects of Hydrostatic Pressure Studied

    NASA Technical Reports Server (NTRS)

    Lewandowski, John J.; Wesseling, Paul; Prabhu, Nishad S.; Larose, Joel; Lissenden, Cliff J.; Lerch, Bradley A.

    2003-01-01

    Aeropropulsion components, such as disks, blades, and shafts, are commonly subjected to multiaxial stress states at elevated temperatures. Experimental results from loadings as complex as those experienced in service are needed to help guide the development of accurate viscoplastic, multiaxial deformation models that can be used to improve the design of these components. During a recent study on multiaxial deformation (ref. 1) on a common aerospace material, Inconel 718, it was shown that the material in the aged state exhibits a strength differential effect (SDE), whereby the uniaxial compressive yield and subsequent flow behavior are significantly higher than those in uniaxial tension. Thus, this material cannot be described by a standard von Mises yield formulation. There have been other formulations postulated (ref. 2) that involve other combinations of the stress invariants, including the effect of hydrostatic stress. The question remained as to which invariants are necessary in the flow model. To capture the physical mechanisms occurring during deformation and reflect them in the plasticity formulation, researchers examined the flow of Inconel 718 under various amounts of hydrostatic stress to determine whether or not hydrostatic stress is needed in the formulation. Under NASA Grant NCC3-464, monitored by the NASA Glenn Research Center, a series of tensile tests were conducted at Case Western Reserve University on aged (precipitation hardened) Inconel 718 at 650 C and with superimposed hydrostatic pressure. Dogbone shaped tensile specimens (3-mm-diameter gauge by 16-mm gauge length) and cylindrical compression specimens (3-mm-diameter gauge by 6-mm gauge length) were strain gauged and loaded in a high-pressure testing apparatus. Hydrostatic pressures were obtained with argon and ranged from 210 to 630 MPa. The aged Inconel 718 showed a pronounced difference in the tension and compression yield strength (i.e., an SDE), as previously observed. Also, there were

  17. Prefrontal Cortex to Accumbens Projections in Sleep Regulation of Reward

    PubMed Central

    Liu, Zheng; Wang, Yao; Cai, Li; Li, Yizhi; Chen, Bo; Dong, Yan

    2016-01-01

    Sleep profoundly affects the emotional and motivational state. In humans and animals, loss of sleep often results in enhanced motivation for reward, which has direct implications for health risks as well as potential benefits. Current study aims at understanding the mechanisms underlying sleep deprivation (SDe)-induced enhancement of reward seeking. We found that after acute SDe, mice had an increase in sucrose seeking and consumption but not food intake, suggesting a selective enhancement of motivation for reward. In the nucleus accumbens (NAc), a key brain region regulating emotional and motivational responses, we observed a decrease in the ratio of the overall excitatory over inhibitory synaptic inputs onto NAc principle neurons after SDe. The shift was partly mediated by reduced glutamatergic transmission of presynaptic origin. Further analysis revealed that there was selective reduction of the glutamate release probability at the medial prefrontal cortex (mPFC)-to-NAc synapses, but not those from the hippocampus, thalamus, or the basal lateral amygdala. To reverse this SDe-induced synaptic alteration, we expressed the stabilized step function opsin (SSFO) in the mPFC; optogenetic stimulation of SSFO at mPFC-to-NAc projection terminals persistently enhanced the action potential-dependent glutamate release. Intra-NAc optogenetic stimulation of SSFO selectively at mPFC-to-NAc terminals restored normal sucrose seeking in mice after SDe without affecting food intake. These results highlight the mPFC-to-NAc projection as a key circuit-based target for sleep to regulate reward-motivated behaviors. SIGNIFICANCE STATEMENT Sleep loss, a costly challenge of modern society, has profound physiological and psychological consequences, including altered reward processing of the brain. The current study aims at understanding the mechanisms underlying sleep deprivation-induced enhancement of reward seeking. We identify that the medial prefrontal cortex (m

  18. Modal Analysis and Model Correlation of the Mir Space Station

    NASA Technical Reports Server (NTRS)

    Kim, Hyoung M.; Kaouk, Mohamed

    2000-01-01

    This paper will discuss on-orbit dynamic tests, modal analysis, and model refinement studies performed as part of the Mir Structural Dynamics Experiment (MiSDE). Mir is the Russian permanently manned Space Station whose construction first started in 1986. The MiSDE was sponsored by the NASA International Space Station (ISS) Phase 1 Office and was part of the Shuttle-Mir Risk Mitigation Experiment (RME). One of the main objectives for MiSDE is to demonstrate the feasibility of performing on-orbit modal testing on large space structures to extract modal parameters that will be used to correlate mathematical models. The experiment was performed over a one-year span on the Mir-alone and Mir with a Shuttle docked. A total of 45 test sessions were performed including: Shuttle and Mir thruster firings, Shuttle-Mir and Progress-Mir dockings, crew exercise and pushoffs, and ambient noise during night-to-day and day-to-night orbital transitions. Test data were recorded with a variety of existing and new instrumentation systems that included: the MiSDE Mir Auxiliary Sensor Unit (MASU), the Space Acceleration Measurement System (SAMS), the Russian Mir Structural Dynamic Measurement System (SDMS), the Mir and Shuttle Inertial Measurement Units (IMUs), and the Shuttle payload bay video cameras. Modal analysis was performed on the collected test data to extract modal parameters, i.e. frequencies, damping factors, and mode shapes. A special time-domain modal identification procedure was used on free-decay structural responses. The results from this study show that modal testing and analysis of large space structures is feasible within operational constraints. Model refinements were performed on both the Mir alone and the Shuttle-Mir mated configurations. The design sensitivity approach was used for refinement, which adjusts structural properties in order to match analytical and test modal parameters. To verify the refinement results, the analytical responses calculated using

  19. HYBRID SULFUR ELECTROLYZER DEVELOPMENT FY09 SECOND QUARTER REPORT

    SciTech Connect

    Herman, D; David Hobbs, D; Hector Colon-Mercado, H; Timothy Steeper, T; John Steimke, J; Mark Elvington, M

    2009-04-15

    The primary objective of the DOE-NE Nuclear Hydrogen Initiative (NHI) is to develop the nuclear hydrogen production technologies necessary to produce hydrogen at a cost competitive with other alternative transportation fuels. The focus of the NHI is on thermochemical cycles and high temperature electrolysis that can be powered by heat from high temperature gas reactors. The Savannah River National Laboratory (SRNL) has been tasked with the primary responsibility to perform research and development in order to characterize, evaluate and develop the Hybrid Sulfur (HyS) thermochemical process. This report documents work during the first quarter of Fiscal Year 2009, for the period between January 1, 2009 and March 31, 2009. The HyS Process is a two-step hybrid thermochemical cycle that is part of the 'Sulfur Family' of cycles. As a sulfur cycle, it uses high temperature thermal decomposition of sulfuric acid to produce oxygen and to regenerate the sulfur dioxide reactant. The second step of the process uses a sulfur dioxide depolarized electrolyzer (SDE) to split water and produce hydrogen by electrochemically reacting sulfur dioxide with H{sub 2}O. The SDE produces sulfuric acid, which is then sent to the acid decomposer to complete the cycle. The DOE NHI program is developing the acid decomposer at Sandia National Laboratory for application to both the HyS Process and the Sulfur Iodine Cycle. The SDE is being developed at SRNL. During FY05 and FY06, SRNL designed and conducted proof-of-concept testing for a SDE using a low temperature, PEM fuel cell-type design concept. The advantages of this design concept include high electrochemical efficiency, small footprint and potential for low capital cost, characteristics that are crucial for successful implementation on a commercial scale. During FY07, SRNL extended the range of testing of the SDE to higher temperature and pressure, conducted a 100-hour longevity test with a 60-cm{sup 2} single cell electrolyzer, and

  20. Toxicity and SidJ-Mediated Suppression of Toxicity Require Distinct Regions in the SidE Family of Legionella pneumophila Effectors.

    PubMed

    Havey, James C; Roy, Craig R

    2015-09-01

    Intracellular bacteria use a variety of strategies to evade degradation and create a replicative niche. Legionella pneumophila is an intravacuolar pathogen that establishes a replicative niche through the secretion of more than 300 effector proteins. The function of most effectors remains to be determined. Toxicity in yeast has been used to identify functional domains and elucidate the biochemical function of effectors. A library of L. pneumophila effectors was screened using an expression plasmid that produces low levels of each protein. This screen identified the effector SdeA as a protein that confers a strong toxic phenotype that inhibits yeast replication. The toxicity of SdeA was suppressed in cells producing the effector SidJ. The effector SdeA is a member of the SidE family of L. pneumophila effector proteins. All SidE orthologs encoded by the Philadelphia isolate of Legionella pneumophila were toxic to yeast, and SidJ suppressed the toxicity of each. We identified a conserved central region in the SidE proteins that was sufficient to mediate yeast toxicity. Surprisingly, SidJ did not suppress toxicity when this central region was produced in yeast. We determined that the amino-terminal region of SidE was essential for SidJ-mediated suppression of toxicity. Thus, there is a genetic interaction that links the activity of SidJ and the amino-terminal region of SidE, which is required to modulate the toxic activity displayed by the central region of the SidE protein. This suggests a complex mechanism by which the L. pneumophila effector SidJ modulates the function of the SidE proteins after translocation into host cells.

  1. Bird and ant synergy increases the seed dispersal effectiveness of an ornithochoric shrub.

    PubMed

    Camargo, Paulo H S A; Martins, Milene M; Feitosa, Rodrigo M; Christianini, Alexander V

    2016-06-01

    Seed dispersal may involve different vectors of dispersal in two or more sequential phases (i.e., diplochory). However, contributions of each phase to the overall seed dispersal effectiveness (SDE) are poorly understood and hard to evaluate due to post-dispersal processes that affect seed and seedling survival. We investigated the simultaneous bird (phase 1, in plant canopy) and ant (phase 2, on the floor) contributions to SDE with the ornithochoric shrub Erythroxylum ambiguum in a Brazilian Atlantic forest. Twelve species of birds fed on fruit and dispersed approximately 26 % of the seed crop. The remaining seed crop, 90 % of which contained viable seeds, fell to the ground beneath the parental plant. Ants either cleaned seeds in fruits or carried fallen fruit and seeds from bird feces to their nests. Although E. ambiguum has no adaptation for ant dispersal, ants were as quantitatively important as birds. Birds and ants equally increased germination rates compared to controls. However, birds deposited seeds farther from the parent, where seedling survival was higher (78 %) than it was beneath the parent (44 %), whereas ants carried seeds to their nests, where seedling survival was higher (83 %) than in controls away from their nests (63 %). Diplochory allowed a 42 % increase in SDE compared to dispersal in phase 1 alone. High lipid content in the fruit pulp of E. ambiguum may facilitate the inclusion of ants in a second step of dispersal after diaspores reach the floor. Ants can also buffer the dispersal of diplochorous plants against decreases in phase 1 dispersers.

  2. Subglacial bedform orientation, one-dimensional size, and directional shape measurement method accuracy

    NASA Astrophysics Data System (ADS)

    Jorge, Marco G.; Brennand, Tracy A.

    2016-04-01

    This study is an assessment of previously reported automated methods and of a new method for measuring longitudinal subglacial bedform (LSB) morphometry. It evaluates the adequacy (accuracy and precision) of orientation, length and longitudinal asymmetry data derived from the longest straight line (LSL) enclosed by the LSB's footprint, the footprint's minimum bounding rectangle longitudinal axis (RLA) and the footprint's standard deviational ellipse (SDE) longitudinal axis (LA) (new method), and the adequacy of length based on an ellipse fitted to the area and perimeter of the footprint (elliptical length). Tests are based on 100 manually mapped drumlins and mega-scale glacial lineations representing the size and shape range of LSBs in the Puget Lowland drumlin field, WA, USA. Data from manually drawn LAs are used as reference for method evaluation. With the exception of elliptical length, errors decrease rapidly with increasing footprint elongation (decreasing potential angular divergence between LAs). For LSBs with elongation <5 and excluding the 5% largest errors (outliers), 1) the LSL, RLA and SDE methods had very small mean absolute error (MAE) in all measures (e.g., MAE <5° in orientation and <5 m in length); they can be confidently used to characterize the central tendency of LSB samples. 2) When analyzing data spatially at large cartographic scales, the LSL method should be avoided for orientation (36% of the errors were larger than 5°). 3) Elliptical length was the least accurate of all methods (MAE of 56.1 m and 15% of the errors larger than 5%); its use should be discontinued. 4) The relative adequacy of the LSL and RLA depends on footprint shape; SDE computed with the footprint's structural vertices is relatively shape-independent and is the preferred method. This study is significant also for negative-relief, and fluvial and aeolian bedforms.

  3. Compositional variance in extracted particulate matter using different filter extraction techniques

    NASA Astrophysics Data System (ADS)

    Bein, K. J.; Wexler, A. S.

    2015-04-01

    Collection and subsequent extraction of particulate matter (PM) from filter substrates is a common requirement for in vivo and in vitro toxicological studies, as well as chemical analyses such as ion chromatography and inductively coupled plasma mass spectrometry. Several filter extraction protocols exist and different laboratories employ different methods, potentially biasing inter-study comparisons. Previous studies have shown significant differences in extraction efficiency between techniques and identified the relevant extraction artifacts. However, a comprehensive inter-comparison of different methods based on the chemical composition of the extracted PM has never been conducted. In the current study, an exhaustive suite of chemical analyses is performed on PM extracted from glass micro-fiber filters using techniques commonly employed in different laboratories: Multi-solvent extraction (MSE) and spin-down extraction (SDE). PM samples were collected simultaneously during field studies conducted in an urban and rural setting using a high-volume PM2.5 sampler. Results show remarkable compositional variance between the PM extracts for all chemical components analyzed, including metals, water soluble ions, polycyclic aromatic hydrocarbons, non-aromatic organics, elemental carbon and organic carbon. Mass closure was greater than 90% for MSE but deviated substantially for SDE. Detailed retrospective gravimetric analysis of archived SDE samples revealed that a process-based loss of PM mass is the root cause of the differences. These losses are shown to be compositionally biased, both externally between different PM mixtures and internally within a given PM mixture. In combination, the results of this study are the first to demonstrate (i) an exhaustive chemical characterization of a single PM extract, (ii) the significance of directly characterizing the extracted PM used in toxicological studies, (iii) the existence of substantial compositional biases between

  4. Neural correlates of relational reasoning and the symbolic distance effect: involvement of parietal cortex.

    PubMed

    Hinton, E C; Dymond, S; von Hecker, U; Evans, C J

    2010-06-16

    A novel, five-term relational reasoning paradigm was employed during functional magnetic resonance imaging to investigate neural correlates of the symbolic distance effect (SDE). Prior to scanning, participants learned a series of more-than (E>D>C>B>A) or less-than (AA) and nonadjacent one-step (AA, D>B and E>C) and two-step (AA and E>B) combinatorial entailed tasks. In terms of brain activation, the SDE was identified in the inferior frontal cortex, dorsolateral prefrontal cortex, and bilateral parietal cortex with a graded activation pattern from adjacent to one-step and two-step relations. We suggest that this captures the behavioural SDE of increased accuracy and decreased reaction time from adjacent to two-step relations. One-step relations involving endpoints A or E resulted in greater parietal activation compared to one-step relations without endpoints. Novel contrasts found enhanced activation in right parietal and prefrontal cortices during mutually entailed tasks only for participants who had learned all less-than relations. Increased parietal activation was found for one-step tasks that were inconsistent with prior training. Overall, the findings demonstrate a crucial role for parietal cortex during relational reasoning with a spatially ordered array.

  5. Intraoperative CT as a registration benchmark for intervertebral motion compensation in image-guided open spinal surgery

    PubMed Central

    Fan, Xiaoyao; Paulsen, Keith D.; Roberts, David W.; Mirza, Sohail K.; Lollis, S. Scott

    2016-01-01

    Purpose An accurate and reliable benchmark of registration accuracy and intervertebral motion compensation is important for spinal image guidance. In this study, we evaluated the utility of intraoperative CT (iCT) in place of bone-implanted screws as the ground-truth registration and illustrated its use to benchmark the performance of intraoperative stereovision (iSV). Methods A template-based, multi-body registration scheme was developed to individually segment and pair corresponding vertebrae between preoperative CT and iCT of the spine. Intervertebral motion was determined from the resulting vertebral pair-wise registrations. The accuracy of the image-driven registration was evaluated using surface-to-surface distance error (SDE) based on segmented bony features and was independently verified using point-to-point target registration error (TRE) computed from bone-implanted mini-screws. Both SDE and TRE were used to assess the compensation accuracy using iSV. Results The iCT-based technique was evaluated on four explanted porcine spines (20 vertebral pairs) with artificially induced motion. We report a registration accuracy of 0.57 ± 0.32 mm (range 0.34–1.14 mm) and 0.29 ± 0.15 mm (range 0.14–0.78 mm) in SDE and TRE, respectively, for all vertebrae pooled, with an average intervertebral rotation of 4.9° ± 1.2° (range 1.5°–7.9°). The iSV-based compensation accuracy for one sample (four vertebrae) was 1.32 ± 0.19 mm and 1.72 ± 0.55 mm in SDE and TRE, respectively, exceeding the recommended accuracy of 2 mm. Conclusion This study demonstrates the effectiveness of iCT in place of invasive fiducials as a registration ground truth. These findings are important for future development of on-demand spinal image guidance using radiation-free images such as stereovision and ultrasound on human subjects. PMID:26194485

  6. The Glass Ceiling for Remotely Piloted Aircraft

    DTIC Science & Technology

    2013-08-01

    Already Are Packed Rated Example Pipeline : 2 years MWS seasoning: 7 years PME: 3 years Sta (Joint): 4 years Command Prep: 2 years Command: 6 years...DO/CC three years —buys one year • Alternatives to Group/CV—one year fly to WG/CC —buys one year Pipeline MWS MWS / FTU / WIC IDE SDE JOINT WG / CC...Reaper squadron to the 28th Bomb Wing at Ellsworth AFB, South Dakota , and another to the 509th Bomb Wing at Whiteman AFB, Missouri. As a rule, wing

  7. Beyond the rainbow: Effects from pion back-coupling

    SciTech Connect

    Fischer, Christian S.; Williams, Richard

    2008-10-01

    We investigate hadronic unquenching effects in light quarks and mesons. To this end, we take into account the back-coupling of the pion onto the quark propagator within the nonperturbative continuum framework of Schwinger-Dyson equations (SDE) and Bethe-Salpeter equations (BSE). We improve on a previous approach by explicitly solving both the coupled system of SDEs and BSEs in the complex plane and the normalization problem for Bethe-Salpeter kernels depending on the total momentum of the meson. As a result of our study, we find considerable unquenching effects in the spectrum of light pseudoscalar, vector and axial-vector mesons.

  8. Non-perturbative QCD and hadron physics

    NASA Astrophysics Data System (ADS)

    Cobos-Martínez, J. J.

    2016-10-01

    A brief exposition of contemporary non-perturbative methods based on the Schwinger-Dyson (SDE) and Bethe-Salpeter equations (BSE) of Quantum Chromodynamics (QCD) and their application to hadron physics is given. These equations provide a non-perturbative continuum formulation of QCD and are a powerful and promising tool for the study of hadron physics. Results on some properties of hadrons based on this approach, with particular attention to the pion distribution amplitude, elastic, and transition electromagnetic form factors, and their comparison to experimental data are presented.

  9. Experimental Validation of Stochastic Wireless Urban Channel Model: Estimation and Prediction

    SciTech Connect

    Kuruganti, Phani Teja; Ma, Xiao; Djouadi, Seddik M

    2012-01-01

    Stochastic differential equations (SDE) can be used to describe the time-varying nature of wireless channels. This paper validates a long-term fading channel model for estimation and prediction from solely using measured received signal strength measurements. Such channel models can be used for optimizing wireless networks deployed for industrial automation, public access, and communication. This paper uses two different sets of received signal measurement data to estimate an predict the signal strength based on past measurements. The realworld performance of the estimation and prediction algorithm is demonstrated.

  10. Concurrent engineering of an infrared telescope system

    NASA Astrophysics Data System (ADS)

    Geis, Jason; Lang, Jeffrey; Peterson, Leslie; Roybal, Francisco; Tanzillo, Jennifer; Thomas, David; Warren, David

    2011-10-01

    A concurrent engineering approach to the design and analysis of a space-borne Electro-Optical (EO) sensor is presented. A detailed design of an infrared telescope payload is developed by an interdisciplinary team of mechanical, structural, thermal, and optical engineers using a Simulation Driven Engineering (SDE) software environment. The telescope payload design is also integrated with a conceptual level design of the space segment of a mission that incorporates the payload. The flow of the concurrent design process is described, and design outputs are provided.

  11. Sensor-to-Shooter C2ISR Integration with Joint Battlespace Infosphere: JBI Client Adapters

    DTIC Science & Technology

    2006-01-01

    Interface LinkPro-PA Entity Table Link16 Enumeration Mappings Entity information To CGIS Aircraft Status Manager Engagement Status Manager Engagement...Oracle 9.2.0.5, BEA WebLogic 8.1, ESRI ArcSDE 9.0, ESRI ArcIMS 9.0, and Sun iPlanet LDAP 5.2—license restrictions may vary depending on the...S for map display (not absolutely required) X ESRI ArcIMS 9.0 C $ S for map display (not absolutely required) X Sun iPlanet LDAP 5.2 C S Sun Java

  12. Comparative study of MnO2 nanoparticle synthesis by marine bacterium Saccharophagus degradans and yeast Saccharomyces cerevisiae.

    PubMed

    Salunke, Bipinchandra K; Sawant, Shailesh S; Lee, Sang-Ill; Kim, Beom Soo

    2015-07-01

    Microorganisms are one of the most attractive and simple sources for the synthesis of different types of metal nanoparticles. The synthesis of manganese dioxide nanoparticles (MnO2 NPs) by microorganisms from reducing potassium permanganate was investigated for the first time in the present study. The microbial supernatants of the bacterium Saccharophagus degradans ATCC 43961 (Sde 2-40) and of the yeast Saccharomyces cerevisiae showed positive reactions to the synthesis of MnO2 NPs by displaying a change of color in the permanganate solution from purple to yellow. KMnO4-specific peaks also disappeared and MnO2-specific peaks emerged at an absorption maximum of 365 nm in UV-visible spectrophotometry. The washed Sde 2-40 cells did not show any ability to synthesize MnO2 NPs. The medium and medium constituents of Sde 2-40 showed similar positive reactions as supernatants, which indicate the role of the Sde 2-40 medium constituents in the synthesis of MnO2 NPs. This suggests that microorganisms without nanoparticle synthesis ability can be misreported for their abilities to synthesize nanoparticles. S. cerevisiae washed cells showed an ability to synthesize MnO2 NPs. The strategies of keeping yeast cells in tea bags and dialysis membranes showed positive tests for the synthesis of MnO2 NPs. A Fourier transform-infrared spectroscopy study suggested roles for the proteins, alcoholic compounds, and cell walls of S. cerevisiae cells in the synthesis of MnO2 NPs. Electron-dispersive X-ray spectroscopy analyses confirmed the presence of Mn and O in the sample. X-ray photoelectron spectroscopy revealed characteristic binding energies for MnO2 NPs. Transmission electron microscopy micrographs revealed the presence of uniformly dispersed hexagonal- and spherical-shaped particles with an average size of 34.4 nm. The synthesis approach using yeast is possible by a simple reaction at low temperature without any need for catalysts, templates, or expensive and precise equipment

  13. Boosting Bayesian parameter inference of stochastic differential equation models with methods from statistical physics

    NASA Astrophysics Data System (ADS)

    Albert, Carlo; Ulzega, Simone; Stoop, Ruedi

    2016-04-01

    Measured time-series of both precipitation and runoff are known to exhibit highly non-trivial statistical properties. For making reliable probabilistic predictions in hydrology, it is therefore desirable to have stochastic models with output distributions that share these properties. When parameters of such models have to be inferred from data, we also need to quantify the associated parametric uncertainty. For non-trivial stochastic models, however, this latter step is typically very demanding, both conceptually and numerically, and always never done in hydrology. Here, we demonstrate that methods developed in statistical physics make a large class of stochastic differential equation (SDE) models amenable to a full-fledged Bayesian parameter inference. For concreteness we demonstrate these methods by means of a simple yet non-trivial toy SDE model. We consider a natural catchment that can be described by a linear reservoir, at the scale of observation. All the neglected processes are assumed to happen at much shorter time-scales and are therefore modeled with a Gaussian white noise term, the standard deviation of which is assumed to scale linearly with the system state (water volume in the catchment). Even for constant input, the outputs of this simple non-linear SDE model show a wealth of desirable statistical properties, such as fat-tailed distributions and long-range correlations. Standard algorithms for Bayesian inference fail, for models of this kind, because their likelihood functions are extremely high-dimensional intractable integrals over all possible model realizations. The use of Kalman filters is illegitimate due to the non-linearity of the model. Particle filters could be used but become increasingly inefficient with growing number of data points. Hamiltonian Monte Carlo algorithms allow us to translate this inference problem to the problem of simulating the dynamics of a statistical mechanics system and give us access to most sophisticated methods

  14. Next-generation text-mining mediated generation of chemical response-specific gene sets for interpretation of gene expression data

    PubMed Central

    2013-01-01

    Background Availability of chemical response-specific lists of genes (gene sets) for pharmacological and/or toxic effect prediction for compounds is limited. We hypothesize that more gene sets can be created by next-generation text mining (next-gen TM), and that these can be used with gene set analysis (GSA) methods for chemical treatment identification, for pharmacological mechanism elucidation, and for comparing compound toxicity profiles. Methods We created 30,211 chemical response-specific gene sets for human and mouse by next-gen TM, and derived 1,189 (human) and 588 (mouse) gene sets from the Comparative Toxicogenomics Database (CTD). We tested for significant differential expression (SDE) (false discovery rate -corrected p-values < 0.05) of the next-gen TM-derived gene sets and the CTD-derived gene sets in gene expression (GE) data sets of five chemicals (from experimental models). We tested for SDE of gene sets for six fibrates in a peroxisome proliferator-activated receptor alpha (PPARA) knock-out GE dataset and compared to results from the Connectivity Map. We tested for SDE of 319 next-gen TM-derived gene sets for environmental toxicants in three GE data sets of triazoles, and tested for SDE of 442 gene sets associated with embryonic structures. We compared the gene sets to triazole effects seen in the Whole Embryo Culture (WEC), and used principal component analysis (PCA) to discriminate triazoles from other chemicals. Results Next-gen TM-derived gene sets matching the chemical treatment were significantly altered in three GE data sets, and the corresponding CTD-derived gene sets were significantly altered in five GE data sets. Six next-gen TM-derived and four CTD-derived fibrate gene sets were significantly altered in the PPARA knock-out GE dataset. None of the fibrate signatures in cMap scored significant against the PPARA GE signature. 33 environmental toxicant gene sets were significantly altered in the triazole GE data sets. 21 of these toxicants

  15. Stable, high-performance operation of a fiber-coupled superconducting nanowire avalanche photon detector

    NASA Astrophysics Data System (ADS)

    Miki, Shigehito; Yabuno, Masahiro; Yamashita, Taro; Terai, Hirotaka

    2017-03-01

    We present a stable and high-performance fiber-coupled NbTiN superconducting nanowire avalanche photon detector (SNAP). We demonstrate afterpulse-free operation in serially connected two SNAPs (SC-2SNAP), even in the absence of a choke inductor, achieving a 7.7 times faster response speed than standard SSPDs. The SC-2SNAP device showed a system detection efficiency (SDE) of 81.0% with wide bias current margin, a dark count rate of 6.8 counts/s, and full width at half maximum timing jitter of 68 ps, operating at 2.3 K.

  16. Rumor spreading model with noise interference in complex social networks

    NASA Astrophysics Data System (ADS)

    Zhu, Liang; Wang, Youguo

    2017-03-01

    In this paper, a modified susceptible-infected-removed (SIR) model has been proposed to explore rumor diffusion on complex social networks. We take variation of connectivity into consideration and assume the variation as noise. On the basis of related literature on virus networks, the noise is described as standard Brownian motion while stochastic differential equations (SDE) have been derived to characterize dynamics of rumor diffusion both on homogeneous networks and heterogeneous networks. Then, theoretical analysis on homogeneous networks has been demonstrated to investigate the solution of SDE model and the steady state of rumor diffusion. Simulations both on Barabási-Albert (BA) network and Watts-Strogatz (WS) network display that the addition of noise accelerates rumor diffusion and expands diffusion size, meanwhile, the spreading speed on BA network is much faster than on WS network under the same noise intensity. In addition, there exists a rumor diffusion threshold in statistical average meaning on homogeneous network which is absent on heterogeneous network. Finally, we find a positive correlation between peak value of infected individuals and noise intensity while a negative correlation between rumor lifecycle and noise intensity overall.

  17. Superconducting detector of IR single-photons based on thin WSi films

    NASA Astrophysics Data System (ADS)

    Seleznev, V. A.; Divochiy, A. V.; Vakhtomin, Yu B.; Morozov, P. V.; Zolotov, P. I.; Vasil'ev, D. D.; Moiseev, K. M.; Malevannaya, E. I.; Smirnov, K. V.

    2016-08-01

    We have developed the deposition technology of WSi thin films 4 to 9 nm thick with high temperature values of superconducting transition (Tc~4 K). Based on deposed films there were produced nanostructures with indicative planar sizes ~100 nm, and the research revealed that even on nanoscale the films possess of high critical temperature values of the superconducting transition (Tc~3.3-3.7 K) which certifies high quality and homogeneity of the films created. The first experiments on creating superconducting single-photon detectors showed that the detectors’ SDE (system detection efficiency) with increasing bias current (I b) reaches a constant value of ~30% (for X=1.55 micron) defined by infrared radiation absorption by the superconducting structure. To enhance radiation absorption by the superconductor there were created detectors with cavity structures which demonstrated a practically constant value of quantum efficiency >65% for bias currents Ib>0.6-Ic. The minimal dark counts level (DC) made 1 s-1 limited with background noise. Hence WSi is the most promising material for creating single-photon detectors with record SDE/DC ratio and noise equivalent power (NEP).

  18. Chemical characterization of Allium ursinum L. depending on harvesting time.

    PubMed

    Schmitt, Barbara; Schulz, Hartwig; Storsberg, Jörg; Keusgen, Michael

    2005-09-07

    Sulfur-containing compounds of ramson (Allium ursinum L.) are responsible for its traditional use in terms of culinary and medicinal purposes. Leaves and bulbs were investigated for their contents of cysteine sulfoxides (volatile precursors) as well as volatile compounds released from minced plant material. Plants were analyzed during the whole vegetation period, focused on the months from March to June. Additionally, within the dormancy period bulbs were analyzed again and alliinase activity was determined. The pattern of volatile compounds was analyzed both by SPME/GC-MS and by SDE/GC-MS. Compared to each other, SDE exhibited a wider spectrum of detectable volatile compounds. The quality and quantity of volatiles significantly depended on the time of harvest. The highest amounts of volatile precursors can be gained in March and April, shortly before flowering time (up to 0.4% of total cysteine sulfoxides). The main cysteine sulfoxides were alliin and isoalliin. It has been found that alliinase of A. ursinum exhibited properties similar to those of alliinase of garlic (Allium sativum L.), but differing in terms of substrate specificity.

  19. A Stochastic Differential Equation Model for the Spread of HIV amongst People Who Inject Drugs.

    PubMed

    Liang, Yanfeng; Greenhalgh, David; Mao, Xuerong

    2016-01-01

    We introduce stochasticity into the deterministic differential equation model for the spread of HIV amongst people who inject drugs (PWIDs) studied by Greenhalgh and Hay (1997). This was based on the original model constructed by Kaplan (1989) which analyses the behaviour of HIV/AIDS amongst a population of PWIDs. We derive a stochastic differential equation (SDE) for the fraction of PWIDs who are infected with HIV at time. The stochasticity is introduced using the well-known standard technique of parameter perturbation. We first prove that the resulting SDE for the fraction of infected PWIDs has a unique solution in (0, 1) provided that some infected PWIDs are initially present and next construct the conditions required for extinction and persistence. Furthermore, we show that there exists a stationary distribution for the persistence case. Simulations using realistic parameter values are then constructed to illustrate and support our theoretical results. Our results provide new insight into the spread of HIV amongst PWIDs. The results show that the introduction of stochastic noise into a model for the spread of HIV amongst PWIDs can cause the disease to die out in scenarios where deterministic models predict disease persistence.

  20. Analysis and Experiments for a Computational Model of a Heat Bath

    NASA Astrophysics Data System (ADS)

    Stuart, A. M.; Warren, J. O.

    1999-11-01

    A question of some interest in computational statistical mechanics is whether macroscopic quantities can be accurately computed without detailed resolution of the fastest scales in the problem. To address this question a simple model for a distinguished particle immersed in a heat bath is studied (due to Ford and Kac). The model yields a Hamiltonian system of dimension 2 N+2 for the distinguished particle and the degrees of freedom describing the bath. It is proven that, in the limit of an infinite number of particles in the heat bath ( N→∞), the motion of the distinguished particle is governed by a stochastic differential equation (SDE) of dimension 2. Numerical experiments are then conducted on the Hamiltonian system of dimension 2 N+2 ( N≫1) to investigate whether the motion of the distinguished particle is accurately computed (i.e., whether it is close to the solution of the SDE) when the time step is small relative to the natural time scale of the distinguished particle, but the product of the fastest frequency in the heat bath and the time step is not small—the underresolved regime in which many computations are performed. It is shown that certain methods accurately compute the limiting behavior of the distinguished particle, while others do not. Those that do not are shown to compute a different, incorrect, macroscopic limit.

  1. Quantum-field-theoretical approach to phase-space techniques: Generalizing the positive-P representation

    SciTech Connect

    Plimak, L.I.; Fleischhauer, M.; Olsen, M.K.; Collett, M.J.

    2003-01-01

    We present an introduction to phase-space techniques (PST) based on a quantum-field-theoretical (QFT) approach. In addition to bridging the gap between PST and QFT, our approach results in a number of generalizations of the PST. First, for problems where the usual PST do not result in a genuine Fokker-Planck equation (even after phase-space doubling) and hence fail to produce a stochastic differential equation (SDE), we show how the system in question may be approximated via stochastic difference equations (S{delta}E). Second, we show that introducing sources into the SDE's (or S{delta}E's) generalizes them to a full quantum nonlinear stochastic response problem (thus generalizing Kubo's linear reaction theory to a quantum nonlinear stochastic response theory). Third, we establish general relations linking quantum response properties of the system in question to averages of operator products ordered in a way different from time normal. This extends PST to a much wider assemblage of operator products than are usually considered in phase-space approaches. In all cases, our approach yields a very simple and straightforward way of deriving stochastic equations in phase space.

  2. Improved diffusion Monte Carlo propagators for bosonic systems using Itô calculus.

    PubMed

    Håkansson, P; Mella, M; Bressanini, Dario; Morosi, Gabriele; Patrone, Marta

    2006-11-14

    The construction of importance sampled diffusion Monte Carlo (DMC) schemes accurate to second order in the time step is discussed. A central aspect in obtaining efficient second order schemes is the numerical solution of the stochastic differential equation (SDE) associated with the Fokker-Plank equation responsible for the importance sampling procedure. In this work, stochastic predictor-corrector schemes solving the SDE and consistent with Itô calculus are used in DMC simulations of helium clusters. These schemes are numerically compared with alternative algorithms obtained by splitting the Fokker-Plank operator, an approach that we analyze using the analytical tools provided by Ito; calculus. The numerical results show that predictor-corrector methods are indeed accurate to second order in the time step and that they present a smaller time step bias and a better efficiency than second order split-operator derived schemes when computing ensemble averages for bosonic systems. The possible extension of the predictor-corrector methods to higher orders is also discussed.

  3. Characterisation of chamomile volatiles by simultaneous distillation solid-phase extraction in comparison to hydrodistillation and simultaneous distillation extraction.

    PubMed

    Krüger, Hans

    2010-05-01

    A new method for complete separation of steam-volatile organic compounds is described using the example of chamomile flowers. This method is based on the direct combination of hydrodistillation and solid-phase extraction in a circulation apparatus. In contrast to hydrodistillation and simultaneous distillation extraction (SDE), an RP-18 solid phase as adsorptive material is used rather than a water-insoluble solvent. Therefore, a prompt and complete fixation of all volatiles takes place, and the circulation of water-soluble bisabololoxides as well as water-soluble and thermolabile en-yne-spiroethers is inhibited. This so-called simultaneous distillation solid-phase extraction (SD-SPE) provides extracts that better characterise the real composition of the vapour phase, as well as the composition of inhalation vapours, than do SDE extracts or essential oils obtained by hydrodistillation. The data indicate that during inhalation therapy with chamomile, the bisabololoxides and spiroethers are more strongly involved in the inhaling activity than so far assumed.

  4. The Impact of Sea-Surface Winds on Meteorological Conditions in Israel: An Initial Study

    NASA Technical Reports Server (NTRS)

    Otterman, J.; Saaroni, H.; Atlas, R.; Ardizzone, J.; Ben-Dor, E.; Druyan, L.; Jusem, C. J.; Karnieli, A.; Terry, J.

    2000-01-01

    The SSM/I (Spectral Sensor Microwave Imager) dataset is used to monitor surface wind speed and direction at four locations over the Eastern Mediterranean during December 1998 - January 1999. Time series of these data are compared to concurrent series of precipitation, surface temperature, humidity and winds at selected Israeli stations: Sde Dov (coastal), Bet Dagan (5 km. inland), Jerusalem (Judean Hills), Hafetz Haim (3 km. inland) and Sde Boker (central Negev). December 1998 and the beginning of January 1999 were dry in Israel, but significant precipitation was recorded at many stations during the second half of January (1999). SSM/I data show a surge in westerly surface winds west of Israel (32 N, 32.5 E) on 15 January, coinciding with the renewal of precipitation. We discuss the relevant circulation and pressure patterns during this transition in the context of the evolving meteorological conditions at the selected Israeli locations. The SSM/I dataset of near ocean surface winds, available for the last 12 years, is described. We analyze lagged correlation between these data and the Israeli station data and investigate possibility of predictive skill. Application of such relationships to short-term weather prediction would require real-time access to the SSM/I observations.

  5. Development of a restricted state space stochastic differential equation model for bacterial growth in rich media.

    PubMed

    Møller, Jan Kloppenborg; Bergmann, Kirsten Riber; Christiansen, Lasse Engbo; Madsen, Henrik

    2012-07-21

    In the present study, bacterial growth in a rich media is analysed in a Stochastic Differential Equation (SDE) framework. It is demonstrated that the SDE formulation and smoothened state estimates provide a systematic framework for data driven model improvements, using random walk hidden states. Bacterial growth is limited by the available substrate and the inclusion of diffusion must obey this natural restriction. By inclusion of a modified logistic diffusion term it is possible to introduce a diffusion term flexible enough to capture both the growth phase and the stationary phase, while concentration is restricted to the natural state space (substrate and bacteria non-negative). The case considered is the growth of Salmonella and Enterococcus in a rich media. It is found that a hidden state is necessary to capture the lag phase of growth, and that a flexible logistic diffusion term is needed to capture the random behaviour of the growth model. Further, it is concluded that the Monod effect is not needed to capture the dynamics of bacterial growth in the data presented.

  6. A study revealing the key aroma compounds of steamed bread made by Chinese traditional sourdough.

    PubMed

    Zhang, Guo-Hua; Wu, Tao; Sadiq, Faizan A; Yang, Huan-Yi; Liu, Tong-Jie; Ruan, Hui; He, Guo-Qing

    Aroma of Chinese steamed bread (CSB) is one of the important parameters that determines the overall quality attributes and consumer acceptance. However, the aroma profile of CSB still remains poorly understood, mainly because of relying on only a single method for aroma extraction in previous studies. Therefore, the objective of this study was to determine the volatile aroma compounds of five different samples of CSB using three different aroma extraction methods, namely solid-phase microextraction (SPME), simultaneous distillation-extraction (SDE), and purge and trap (P&T). All samples showed a unique aroma profile, which could be attributed to their unique microbial consortia. (E)-2-Nonenal and (E,E)-2,4-decadienal were the most prevalent aromatic compounds revealed by SDE, which have not been reported previously, while ethanol and acetic acid proved to be the most dominant compounds by both SPME and P&T. Our approach of combining three different aroma extraction methods provided better insights into the aroma profile of CSB, which had remained largely unknown in previous studies.

  7. Determination of phthalate esters in teas and tea infusions by gas chromatography-mass spectrometry.

    PubMed

    Du, Liping; Ma, Lijuan; Qiao, Yang; Lu, Yan; Xiao, Dongguang

    2016-04-15

    Phthalate esters (PAEs), a group of environmental pollutants which are carcinogenic to human body, have been detected in teas. In this work, five PAEs in teas and tea infusions were quantitatively determined by a modified simultaneous distillation extraction (SDE) coupled with gas chromatography-mass spectrometry. After the optimization of SDE, the proposed method afforded a wide range of linearity and high linear regression coefficients with the limits of detection range of 0.24-3.72 μg/kg. The average recoveries were 79.83-116.67% for tea samples and 78.22-101.64% for tea infusions with all the relative standard deviations below 20%. The total content of five PAEs in teas was 1.135-3.734 mg/kg and the total dissolving ratio of five PAEs from tea to infusion was 19.05-28.07% for the selected tea samples. The risk assessment result of all the selected tea samples demonstrated that the population with the habit of drinking tea won't cause risk to human health.

  8. Regional heart motion abnormality detection via information measures and unscented Kalman filtering.

    PubMed

    Punithakumar, Kumaradevan; Ben Ayed, Ismail; Islam, Ali; Ross, Ian G; Li, Shuo

    2010-01-01

    This study investigates regional heart motion abnormality detection using various classifier features with Shannon's Differential Entropy (SDE). Rather than relying on elementary measurements or a fixed set of moments, the SDE measures global distribution information and, as such, has more discriminative power in classifying distributions. Based on functional images, which are subject to noise and segmentation inaccuracies, heart wall motion analysis is acknowledged as a difficult problem and, therefore, incorporation of prior knowledge is desirable to enhance the accuracy. Given noisy data and nonlinear dynamic model to describe the myocardial motion, unscented Kalman filter, a recursive nonlinear Bayesian filter, is devised in this study so as to estimate LV cavity points. Subsequently, a naive Bayes classifier algorithm is constructed from the SDEs of different features in order to automatically detect abnormal functional regions of the myocardium. Using 90 x 20 segmented LV cavities of short-axis magnetic resonance images obtained from 30 subjects, the experimental analysis carried over 480 myocardial segments demonstrates that the proposed method perform significantly better than other recent methods, and can lead to a promising diagnostic support tool to assist clinicians.

  9. Characteristics of Cluster Implantation and Low Diffusion Annealing

    SciTech Connect

    Nagayama, Tsutomu; Hamamoto, Nariaki; Umisedo, Sei; Tanjyo, Masayasu; Ootsuka, Fumio; Aoyama, Takayuki

    2008-11-03

    Beyond 45 nm device fabrication, it is recognized that the ultra-shallow junction (USJ) formation is required, which is achieved by the ultra-low energy ion implantation and ultra-low diffusion annealing. For this purpose, Cluster ion implantation (CII) and the Flash lamp annealing (FLA) activation processes have been developed. In this paper, we introduce characteristics of activation using B{sub 18}Hx{sup +} implantation with FLA, which are applied to a source drain extension (SDE) for pMOSFET in Hgh-k/metal process. We will prove that the combined process of B{sub 18}Hx{sup +} and FLA can make the low sheet resistance and the fine crystal recovery for USJ formation such a SDE. Moreover, the combined process of C{sub 7}Hx{sup +} implantation and FLA can make the high stress region for nMOSFET by the high substitutional Carbon. If both of B{sub 18}Hx{sup +} implantation and C{sub 7}Hx{sup +} implantation with FLA are applied to High-k/metal process, it will give the highest performance. The combination of FLA and cluster ion implanter ''CLARIS'' which is developed for IC fabrication, will promise the most powerful performance beyond 45 nm node device.

  10. Fractionation and identification of minor and aroma-active constituents in Kangra orthodox black tea.

    PubMed

    Joshi, Robin; Gulati, Ashu

    2015-01-15

    The aroma constituents of Kangra orthodox black tea were isolated by simultaneous distillation extraction (SDE), supercritical fluid extraction and beverage method. The aroma-active compounds were identified using gas chromatography-olfactometry-mass spectrometry. Geraniol, linalool, (Z/E)-linalool oxides, (E)-2-hexenal, phytol, β-ionone, hotrienol, methylpyrazine and methyl salicylate were major volatile constituents in all the extracts. Minor volatile compounds in all the extracts were 2-ethyl-5-methylpyrazine, ethylpyrazine, 2-6,10,14-trimethyl-2-pentadecanone, acetylfuran, hexanoic acid, dihydroactinidiolide and (E/Z)-2,6-nonadienal. The concentrated SDE extract was fractionated into acidic, basic, water-soluble and neutral fractions. The neutral fraction was further chromatographed on a packed silica gel column eluted with pentane and diethyl ether to separate minor compounds. The aroma-active compounds identified using gas chromatography-olfactometry-mass spectrometry were 2-amylfuran, (E/Z)-2,6-nonadienal, 1-pentanol, epoxylinalool, (Z)-jasmone, 2-acetylpyrrole, farnesyl acetone, geranyl acetone, cadinol, cubenol and dihydroactinidiolide. AEDA studies showed 2-hexenal, 3-hexenol, ethylpyrazine, (Z/E)-linalool oxides, linalool, (E/Z)-2,6-nonadienal, geraniol, phenylethanol, β-ionone, hotrienol and dihydroactinidiolide to be odour active components.

  11. Discovery and Characterization of Cadherin Domains in Saccharophagus degradans 2-40▿ †

    PubMed Central

    Fraiberg, Milana; Borovok, Ilya; Weiner, Ronald M.; Lamed, Raphael

    2010-01-01

    Saccharophagus degradans strain 2-40 is a prominent member of newly discovered group of marine and estuarine bacteria that recycle complex polysaccharides. The S. degradans 2-40 genome codes for 15 extraordinary long polypeptides, ranging from 274 to 1,600 kDa. Five of these contain at least 52 cadherin (CA) and cadherin-like (CADG) domains, the types of which were reported to bind calcium ions and mediate protein/protein interactions in metazoan systems. In order to evaluate adhesive features of these domains, recombinant CA doublet domains (two neighboring domains) from CabC (Sde_3323) and recombinant CADG doublet domains from CabD (Sde_0798) were examined qualitatively and quantitatively for homophilic and heterophilic interactions. In addition, CA and CADG doublet domains were tested for adhesion to the surface of S. degradans 2-40. Results showed obvious homophilic and heterophilic, calcium ion-dependent interactions between CA and CADG doublet domains. Likewise, CA and CADG doublet domains adhered to the S. degradans 2-40 surface of cells that were grown on xylan from birch wood or pectin, respectively, as a sole carbon source. This research shows for the first time that bacterial cadherin homophilic and heterophilic interactions may be similar in their nature to cadherin domains from metazoan lineages. We hypothesize that S. degradans 2-40 cadherin and cadherin-like multiple domains contribute to protein-protein interactions that may mediate cell-cell contact in the marine environment. PMID:20023015

  12. The hallucinogenic herb Salvia divinorum and its active ingredient salvinorin A reduce inflammation-induced hypermotility in mice.

    PubMed

    Capasso, R; Borrelli, F; Zjawiony, J; Kutrzeba, L; Aviello, G; Sarnelli, G; Capasso, F; Izzo, A A

    2008-02-01

    The hallucinogenic plant Salvia divinorum has been used for medical treatments of gastrointestinal disorders. Here, we evaluated the effect of a standardized extract from the leaves of Salvia divinorum (SDE) and of its active ingredient salvinorin A on motility in vivo, both in physiological states and during croton oil-induced intestinal inflammation. SDE (1-100 mg kg(-1)) significantly inhibited motility only in inflamed, but not in control, mice. In control mice, salvinorin A (0.01-10 mg kg(-1)) significantly inhibited motility only at the highest doses tested (3 and 10 mg kg(-1)) and this effect was not counteracted by naloxone or by the kappa-opioid receptor (KOR) antagonist nor-binaltorphimine. Inflammation significantly increased the potency of salvinorin A (but not of the KOR agonist U-50488) in reducing motility. The inhibitory effects of both salvinorin A and U-50488 in inflamed mice were counteracted by naloxone or by nor-binaltorphimine. We conclude that salvinorin A may reduce motility through activation of different targets. In physiological states, salvinorin A, at high doses, inhibited motility through a non-KOR mediated mechanism. Gut inflammation increased the potency of salvinorin A; this effect was mediated by KOR, but it was not shared by U-50488, thus suggesting that salvinorin A may have target(s) other than KOR in the inflamed gut.

  13. Using stochastic models calibrated from nanosecond nonequilibrium simulations to approximate mesoscale information

    PubMed Central

    Calderon, Christopher P.; Janosi, Lorant; Kosztin, Ioan

    2009-01-01

    We demonstrate how the surrogate process approximation (SPA) method can be used to compute both the potential of mean force along a reaction coordinate and the associated diffusion coefficient using a relatively small number (10–20) of bidirectional nonequilibrium trajectories coming from a complex system. Our method provides confidence bands which take the variability of the initial configuration of the high-dimensional system, continuous nature of the work paths, and thermal fluctuations into account. Maximum-likelihood-type methods are used to estimate a stochastic differential equation (SDE) approximating the dynamics. For each observed time series, we estimate a new SDE resulting in a collection of SPA models. The physical significance of the collection of SPA models is discussed and methods for exploiting information in the population of estimated SPA models are demonstrated and suggested. Molecular dynamics simulations of potassium ion dynamics inside a gramicidin A channel are used to demonstrate the methodology, although SPA-type modeling has also proven useful in analyzing single-molecule experimental time series [J. Phys. Chem. B 113, 118 (2009)]. PMID:19368472

  14. Kinematic dynamo, supersymmetry breaking, and chaos

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, Igor V.; Enßlin, Torsten A.

    2016-04-01

    The kinematic dynamo (KD) describes the growth of magnetic fields generated by the flow of a conducting medium in the limit of vanishing backaction of the fields onto the flow. The KD is therefore an important model system for understanding astrophysical magnetism. Here, the mathematical correspondence between the KD and a specific stochastic differential equation (SDE) viewed from the perspective of the supersymmetric theory of stochastics (STS) is discussed. The STS is a novel, approximation-free framework to investigate SDEs. The correspondence reported here permits insights from the STS to be applied to the theory of KD and vice versa. It was previously known that the fast KD in the idealistic limit of no magnetic diffusion requires chaotic flows. The KD-STS correspondence shows that this is also true for the diffusive KD. From the STS perspective, the KD possesses a topological supersymmetry, and the dynamo effect can be viewed as its spontaneous breakdown. This supersymmetry breaking can be regarded as the stochastic generalization of the concept of dynamical chaos. As this supersymmetry breaking happens in both the diffusive and the nondiffusive cases, the necessity of the underlying SDE being chaotic is given in either case. The observed exponentially growing and oscillating KD modes prove physically that dynamical spectra of the STS evolution operator that break the topological supersymmetry exist with both real and complex ground state eigenvalues. Finally, we comment on the nonexistence of dynamos for scalar quantities.

  15. Comparison of Essential Oils Obtained from Different Extraction Techniques as an Aid in Identifying Aroma Significant Compounds of Nutmeg (Myristica fragrans).

    PubMed

    Chatterjee, Suchandra; Gupta, Sumit; Variyar, S Prasad

    2015-08-01

    Distribution of volatile constituents in the essential oil of nutmeg obtained by simultaneous distillation extraction (SDE), high vacuum distillation (HVD) and super critical fluid extraction (SFE) was compared with reduced pressure distillation (RPD) and head space (HS) analysis. HS and RPD volatiles were characterized by a high content of sabinene, followed by α-pinene and β-pinene. Interestingly, unlike the SDE, HVD and SFE oils, distillates from HS and RPD were marked by the absence of phenolic ethers namely myristicin, elemicin and safrole. The HS and RPD volatiles possessed a pleasant nutmeg aroma indicating a significant role of terpenic constituents in contributing to the top aroma note. GC-olfactometry (GC-O) of the oils aided in establishing the role of sabinene, α-pinene and β-pinene in contributing to the distinctive note of the spice. A high odor activity value (OAV) of sabinene and α-pinene established the role of these two constituents in imparting the characteristic nutmeg odor.

  16. Changes in flavor volatile composition of oolong tea after panning during tea processing.

    PubMed

    Sheibani, Ershad; Duncan, Susan E; Kuhn, David D; Dietrich, Andrea M; Newkirk, Jordan J; O'Keefe, Sean F

    2016-05-01

    Panning is a processing step used in manufacturing of some varieties of oolong tea. There is limited information available on effects of panning on oolong tea flavors. The goal of this study was to determine effects of panning on flavor volatile compositions of oolong using Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Olfactometry (GC-O). SDE and SPME techniques were applied for extraction of volatiles in panned and unpanned teas. A total of 190 volatiles were identified from SDE and SPME extractions using GC-MS and GC-O. There were no significant differences (P > 0.05) in aldehyde or terpene contents of unpanned and panned tea. However, alcohols, ketones, acids and esters contents were significantly reduced by panning. Among 12 major volatiles previously used for identification and quality assessment of oolong tea, trans nerolidol, 2- hexenal, benzaldehyde, indole, gernaiol, and benzenacetaldehyde contents were significantly decreased (P < 0.05) by panning. Panning increased (P < 0.05) contents of linalool oxide, cis jasmone, and methyl salicylate. The GC-O study also showed an increase of aroma active compounds with sweet descriptions and decrease of aroma active compounds with fruity and smoky descriptions after panning. Panning significantly changes the volatile compositions of the tea and created new aroma active compounds. Results from this study can be used in quality assessment of panned oolong tea.

  17. A study revealing the key aroma compounds of steamed bread made by Chinese traditional sourdough*

    PubMed Central

    Zhang, Guo-hua; Wu, Tao; Sadiq, Faizan A.; Yang, Huan-yi; Liu, Tong-jie; Ruan, Hui; He, Guo-qing

    2016-01-01

    Aroma of Chinese steamed bread (CSB) is one of the important parameters that determines the overall quality attributes and consumer acceptance. However, the aroma profile of CSB still remains poorly understood, mainly because of relying on only a single method for aroma extraction in previous studies. Therefore, the objective of this study was to determine the volatile aroma compounds of five different samples of CSB using three different aroma extraction methods, namely solid-phase microextraction (SPME), simultaneous distillation–extraction (SDE), and purge and trap (P&T). All samples showed a unique aroma profile, which could be attributed to their unique microbial consortia. (E)-2-Nonenal and (E,E)-2,4-decadienal were the most prevalent aromatic compounds revealed by SDE, which have not been reported previously, while ethanol and acetic acid proved to be the most dominant compounds by both SPME and P&T. Our approach of combining three different aroma extraction methods provided better insights into the aroma profile of CSB, which had remained largely unknown in previous studies. PMID:27704748

  18. Three predictions: Comet 67P/Churyumov-Gerasimenko, comet C/2012 K1 PANSTARRS, and comet C/2013 V5 Oukaimeden

    NASA Astrophysics Data System (ADS)

    Ferrín, Ignacio

    2014-09-01

    We make the following predictions: (1) The secular light curve (SLC) of comet 67P/Churyumov-Gerasimenko exhibits a photometric anomaly in magnitude that is present in 1982, 1996, 2002 and 2009. Thus it must be real. We interpret this anomaly as a topographic feature on the surface of the nucleus that may be a field of debris, a region made only of dust or an area of solid stones but in any case it is depleted in volatiles. We predict that images taken by spacecraft Rosetta will show a region morphologically different to the rest of the nucleus, at the pole pointing to the Sun near perihelion. (2) Comet C/2012 K1 PANSTARRS exhibits the same Slope Discontinuity Event (SDE)+magnitude dip after the event than other comets listed in Table 1 most of which disintegrated. This group includes comet C/2012 S1 ISON. Thus, it is reasonable to expect that this comet may disintegrate too. The probability of disintegration of this comet is 27%. (3) Comet C/2013 V5 Oukaimeden exhibits the same SDE+standstill signature exhibited by other comets in Table 1. We predict that there is a 93% probability that this comet will disintegrate. (4) Another purpose of this work is to present evidence to conclude that the SLCs have predictive power.

  19. Charmonia in a contact interaction

    NASA Astrophysics Data System (ADS)

    Bedolla, Marco A.; Cobos-Martínez, J. J.; Bashir, Adnan

    2015-09-01

    For the flavor-singlet heavy quark system of charmonia, we compute the masses of the ground state mesons in four different channels: pseudoscalar [ηc(1 S )], vector [J /Ψ (1 S )], scalar [χc0(1P )] and axial vector [χc 1(1 P )], as well as the weak decay constants of the ηc(1 S ) and J /Ψ (1 S ) and the charge radius of ηc(1 S ). The framework for this analysis is provided by a symmetry-preserving Schwinger-Dyson equation (SDE) treatment of a vector×vector contact interaction. The results found for the meson masses and the weak decay constants, for the spin-spin combinations studied, are in fairly good agreement with experimental data and earlier model calculations based upon Schwinger-Dyson and Bethe-Salpeter equations involving sophisticated interaction kernels. The charge radius of ηc(1 S ) is consistent with the results from refined SDE studies and lattice quantum chromodynamics.

  20. Degradation of phthalate and di-(2-ethylhexyl)phthalate by indigenous and inoculated microorganisms in sludge-amended soil

    SciTech Connect

    Roslev, P.; Madsen, P.L.; Thyme, J.B.; Henriksen, K.

    1998-12-01

    The metabolism of phthalic acid (PA) and di-(2-ethylhexyl) (DEHP) in sludge-amended agricultural soil was studied with radiotracer techniques. The initial rates of metabolism of PA and DEHP were estimated to be 731.8 and 25.6 pmol/g (dry weight) per day, respectively. Indigenous microorganisms assimilated 28 and 17% of the carbon in [{sup 14}C]PA and [{sup 14}C]DEHP, respectively, into microbial biomass. The rates of DEHP metabolism were much greater in sludge assays without soil than in assays with sludge-amended soil. Mineralization of [{sup 14}C]DEHP to {sup 14}CO{sub 2} increased fourfold after inoculation of sludge and soil samples with DEHP-degrading strain SDE 2. The elevated mineralization potential was maintained for more than 27 days. Experiments performed with strain SDE 2 suggested that the bioavailability and mineralization of DEHP decreased substantially in the presence of soil and sludge components. The microorganisms metabolizing PA and DEHP in sludge and sludge-amended soil were characterized by substrate-specific radiolabelling, followed by analysis of {sup 14}C-labelled phospholipid ester-linked fatty acids ({sup 14}C-PLFAs).

  1. Comparison of different extraction methods for the analysis of volatile secondary metabolites of Lippia alba (Mill.) N.E. Brown, grown in Colombia, and evaluation of its in vitro antioxidant activity.

    PubMed

    Stashenko, Elena E; Jaramillo, Beatriz E; Martínez, Jairo René

    2004-01-30

    Hydrodistillation (HD), simultaneous distillation solvent extraction (SDE), microwave-assisted hydrodistillation (MWHD), and supercritical fluid (CO2) extraction (SFE) were employed to isolate volatile secondary metabolites from fresh leaves and stems of Colombian Lippia alba (Mill.) N.E. Brown. Kovàts indices, mass spectra or standard compounds were used to identify around 40 components in the various volatile fractions. Carvone (40-57%) was the most abundant component, followed by limonene (24-37%), bicyclosesquiphellandrene (5-22%), piperitenone (1-2%), piperitone (ca. 1.0%), and beta-bourbonene (0.6-1.5%), in the HD, SDE, MWHD, and SFE volatile fractions. Static headspace (S-HS), simultaneous purge and trap in solvent (CH2Cl2) (P&T), and headspace solid-phase microextraction (HS-SPME) were used to sample volatiles from fresh L. alba stems and leaves. The main components isolated from the headspace of the fresh plant material were limonene (27-77%), carvone (14-30%), piperitone (0.3-0.5%), piperitenone (ca. 0.4%), and beta-bourbonene (0.5-6.5%). The in vitro antioxidant activity of L. alba essential oil, obtained by hydrodistillation was evaluated by determination of hexanal, the main carbonyl compound released by linoleic acid subjected to peroxidation (1 mm Fe2+, 37 degrees C, 12 h), and by quantification of this acid as its methyl ester. Under the same conditions, L. alba HD-essential oil and Vitamin E exhibited similar antioxidant effects.

  2. An integrated GIS application system for soil moisture data assimilation

    NASA Astrophysics Data System (ADS)

    Wang, Di; Shen, Runping; Huang, Xiaolong; Shi, Chunxiang

    2014-11-01

    The gaps in knowledge and existing challenges in precisely describing the land surface process make it critical to represent the massive soil moisture data visually and mine the data for further research.This article introduces a comprehensive soil moisture assimilation data analysis system, which is instructed by tools of C#, IDL, ArcSDE, Visual Studio 2008 and SQL Server 2005. The system provides integrated service, management of efficient graphics visualization and analysis of land surface data assimilation. The system is not only able to improve the efficiency of data assimilation management, but also comprehensively integrate the data processing and analysis tools into GIS development environment. So analyzing the soil moisture assimilation data and accomplishing GIS spatial analysis can be realized in the same system. This system provides basic GIS map functions, massive data process and soil moisture products analysis etc. Besides,it takes full advantage of a spatial data engine called ArcSDE to effeciently manage, retrieve and store all kinds of data. In the system, characteristics of temporal and spatial pattern of soil moiture will be plotted. By analyzing the soil moisture impact factors, it is possible to acquire the correlation coefficients between soil moisture value and its every single impact factor. Daily and monthly comparative analysis of soil moisture products among observations, simulation results and assimilations can be made in this system to display the different trends of these products. Furthermore, soil moisture map production function is realized for business application.

  3. GC/MS analysis of volatiles obtained by headspace solid-phase microextraction and simultaneous-distillation extraction from Rabdosia serra (MAXIM.) HARA leaf and stem.

    PubMed

    Lin, Lianzhu; Zhuang, Mingzhu; Lei, Fenfen; Yang, Bao; Zhao, Mouming

    2013-01-15

    Volatiles in Rabdosia serra were investigated by headspace solid phase microextraction (HS-SPME) and simultaneous-distillation extraction (SDE). The HS-SPME technique was previously evaluated to optimise sampling conditions. A total of 56 and 48 compounds including alcohols, aldehydes, hydrocarbons, ketones, carboxylic acid, ester, and aromatics were identified in leaf and stem by optimised HS-SPME method (CAR/PDMS fibre; incubation time, 10 min; extraction temperature, 50°C; extraction time, 40 min), respectively. 1-Octen-3-ol and (2E)-hexenal had significant contribution to R. serra aroma. Cluster analysis indicated that leaf and stem exhibited different volatile diversity. Air drying was favourable for the retention of the volatiles, while freeze- and sun-drying led to the loss of volatiles. SDE method preferred to the analysis of compounds with low volatility including fatty acids and esters. HS-SPME was a useful technique for the analysis of readily volatile components for the characteristics of R. serra aroma.

  4. A Stochastic Differential Equation Model for the Spread of HIV amongst People Who Inject Drugs

    PubMed Central

    Mao, Xuerong

    2016-01-01

    We introduce stochasticity into the deterministic differential equation model for the spread of HIV amongst people who inject drugs (PWIDs) studied by Greenhalgh and Hay (1997). This was based on the original model constructed by Kaplan (1989) which analyses the behaviour of HIV/AIDS amongst a population of PWIDs. We derive a stochastic differential equation (SDE) for the fraction of PWIDs who are infected with HIV at time. The stochasticity is introduced using the well-known standard technique of parameter perturbation. We first prove that the resulting SDE for the fraction of infected PWIDs has a unique solution in (0, 1) provided that some infected PWIDs are initially present and next construct the conditions required for extinction and persistence. Furthermore, we show that there exists a stationary distribution for the persistence case. Simulations using realistic parameter values are then constructed to illustrate and support our theoretical results. Our results provide new insight into the spread of HIV amongst PWIDs. The results show that the introduction of stochastic noise into a model for the spread of HIV amongst PWIDs can cause the disease to die out in scenarios where deterministic models predict disease persistence. PMID:27051461

  5. Design and Experimental Test Plan for Hybrid Sulfur Single Cell Pressurized Electrolyzer

    SciTech Connect

    Steeper, T. J.; Steimke, J. L.

    2005-09-01

    The Hybrid Sulfur (HyS) process is one of the leading thermochemical cycles being studied as part of the DOE Nuclear Hydrogen Initiative (NHI). SRNL is conducting analyses and research and development for the Department of Energy on the HyS process. A conceptual design report and development plan for the HyS process was issued on April 1, 2005 [Buckner, et. al., 2005] , and a report on atmospheric testing of a sulfur dioxide depolarized electrolyzer (SDE), a major component of the HyS process, was issued on August 1, 2005 [Steimke, 2005]. The purpose of this report is to document work related to the design and experimental test plan for a pressurized SDE. Pressurized operation of the SDE is a key requirement for development of an efficient and cost-effective HyS process. The HyS process, a hybrid thermochemical cycle proposed and investigated in the 1970s and early 1980s by Westinghouse Electric Corporation, is a high priority candidate for NHI due to the potential for high efficiency and its relatively high level of technical maturity. It was demonstrated in laboratory experiments by Westinghouse in 1978. Process improvements and component advancements that build on that work are being pursued. One of the objectives of the current work is to develop the SDE in order to permit the demonstration of a closed-loop laboratory model of the HyS process. The heart of the HyS process for generating hydrogen is a bank of electrolyzers incorporating sulfur dioxide depolarized anodes. SRNL planned, designed, built and operated a facility for testing single cell electrolyzers at ambient temperature and near atmospheric pressure during the spring and summer of 2005. The major contribution of the SRNL work was the establishment of the proof-of-concept for utilizing the proton-exchange-membrane (PEM) cell design for the SDE operation. Since PEM cells are being extensively developed for automotive fuel cell use, they offer significant potential for cost-effective application for

  6. FY08 MEMBRANE CHARACTERIZATION REPORT FOR HYBRID SULFUR ELECTROLYZER

    SciTech Connect

    Hobbs, D; Hector Colon-Mercado, H; Mark Elvington, M

    2008-09-01

    This report summarizes results from all of the membrane testing completed to date at the Savannah River National Laboratory (SRNL) for the sulfur dioxide-depolarized electrolyzer (SDE). Several types of commercially-available membranes have been analyzed for ionic resistance and sulfur dioxide transport including perfluorinated sulfonic acid (PFSA), sulfonated polyether-ketone-ketone (SPEKK), and polybenzimidazole membranes (PBI). Of these membrane types, the poly-benzimidazole membrane, Celtec-L, exhibited the best combination of characteristics for use in an SDE. Several experimental membranes have also been analyzed including hydrated sulfonated Diels-Alder polyphenylenes (SDAPP) membranes from Sandia National Laboratory, perfluorosulfonimide (PFSI) and sulfonated perfluorocyclobutyl aromatic ether (S-PFCB) prepared by Clemson University, hydrated platinum-treated PFSA prepared by Giner Electrochemical Systems (GES) and Pt-Nafion{reg_sign} 115 composites prepared at SRNL. The chemical stability, SO{sub 2} transport and ionic conductivity characteristics have been measured for several commercially available and experimental proton-conducting membranes. Commercially available PFSA membranes such as the Nafion{reg_sign} series exhibited excellent chemical stability and ionic conductivity in sulfur dioxide saturated sulfuric acid solutions. Sulfur dioxide transport in the Nafion{reg_sign} membranes varied proportionally with the thickness and equivalent weight of the membrane. Although the SO{sub 2} transport in the Nafion{reg_sign} membranes is higher than desired, the excellent chemical stability and conductivity makes this membrane the best commercially-available membrane at this time. Initial results indicated that a modified Nafion{reg_sign} membrane incorporating Pt nanoparticles exhibited significantly reduced SO{sub 2} transport. Reduced SO{sub 2} transport was also measured with commercially available PBI membrane and several experimental membranes produced

  7. A stochastic model for adhesion-mediated cell random motility and haptotaxis.

    PubMed

    Dickinson, R B; Tranquillo, R T

    1993-01-01

    The active migration of blood and tissue cells is important in a number of physiological processes including inflammation, wound healing, embryogenesis, and tumor cell metastasis. These cells move by transmitting cytoplasmic force through membrane receptors which are bound specifically to adhesion ligands in the surrounding substratum. Recently, much research has focused on the influence of the composition of extracellular matrix and the distribution of its components on the speed and direction of cell migration. It is commonly believed that the magnitude of the adhesion influences cell speed and/or random turning behavior, whereas a gradient of adhesion may bias the net direction of the cell movement, a phenomenon known as haptotaxis. The mechanisms underlying these responses are presently not understood. A stochastic model is presented to provide a mechanistic understanding of how the magnitude and distribution of adhesion ligands in the substratum influence cell movement. The receptor-mediated cell migration is modeled as an interrelation of random processes on distinct time scales. Adhesion receptors undergo rapid binding and transport, resulting in a stochastic spatial distribution of bound receptors fluctuating about some mean distribution. This results in a fluctuating spatio-temporal pattern of forces on the cell, which in turn affects the speed and turning behavior on a longer time scale. The model equations are a system of nonlinear stochastic differential equations (SDE's) which govern the time evolution of the spatial distribution of bound and free receptors, and the orientation and position of the cell. These SDE's are integrated numerically to simulate the behavior of the model cell on both a uniform substratum, and on a gradient of adhesion ligand concentration. Furthermore, analysis of the governing SDE system and corresponding Fokker-Planck equation (FPE) yields analytical expressions for indices which characterize cell movement on multiple time

  8. Flavor deterioration in yogurt.

    PubMed

    Harasawa, N; Tateba, H; Ishizuka, N; Wakayama, T; Kishino, K; Ono, M

    1998-01-01

    Volatile components of flavored yogurt preserved at 5 degrees C in the dark for 0 day, 3 days and 10 days were recovered by simultaneous distillation extraction (SDE) and headspace (HS) procedures. Gas chromatography (GC) and GC-mass spectrometry (GC-MS) analyses of those samples showed remarkable changes in some compounds. Aldehydes which contribute to expressing citrusy notes were reduced to alcohols during fermentation process and storage. As a result, the strength of flavors which expressed well-balanced citrusy notes in yogurt were weakened, and fatty or oily notes mainly caused from alcohols were strengthened reversely. Hydrocarbons were also digested by bacteria during a fermentation process. A small amount of other compounds, such as esters and terpene alcohols changed. Fewer effects of sorption into a package material and chemical reactions, such as hydrolysis esters, hydration or oxidation of hydrocarbons, were observed.

  9. NYC Reservoirs Watershed Areas (HUC 12)

    EPA Pesticide Factsheets

    This NYC Reservoirs Watershed Areas (HUC 12) GIS layer was derived from the 12-Digit National Watershed Boundary Database (WBD) at 1:24,000 for EPA Region 2 and Surrounding States. HUC 12 polygons were selected from the source based on interactively comparing these HUC 12s in our GIS with images of the New York City's Water Supply System Map found at http://www.nyc.gov/html/dep/html/drinking_water/wsmaps_wide.shtml. The 12 digit Hydrologic Units (HUCs) for EPA Region 2 and surrounding states (Northeastern states, parts of the Great Lakes, Puerto Rico and the USVI) are a subset of the National Watershed Boundary Database (WBD), downloaded from the Natural Resources Conservation Service (NRCS) Geospatial Gateway and imported into the EPA Region 2 Oracle/SDE database. This layer reflects 2009 updates to the WBD that included new boundary data for New York and New Jersey.

  10. GC-MS-olfactometric characterization of the most aroma-active components in a representative aromatic extract from Iranian saffron (Crocus sativus L.).

    PubMed

    Amanpour, Asghar; Sonmezdag, A Salih; Kelebek, Hasim; Selli, Serkan

    2015-09-01

    Aroma and aroma-active compounds of Iranian saffron (Crocus sativus L.) were analyzed by gas chromatography-mass spectrometry-olfactometry. The saffron aromatic extracts were obtained by four different extraction techniques including solvent-assisted flavour evaporation (SAFE), liquid-liquid extraction (LLE), solid phase extraction (SPE), and simultaneous distillation extraction (SDE) and compared to achieve a representative aromatic extract from saffron. According to sensory analysis, the aromatic extract obtained by SAFE was the most representative of saffron odour. A total of 28 aroma compounds were identified in saffron. Ketones were quantitatively the most dominant volatiles in saffron, followed by aldehydes and acids. Aroma extract dilution analysis (AEDA) was used for the determination of aroma-active compounds of saffron. A total of nine aroma-active compounds were detected in the aromatic extract. On the basis of the flavour dilution (FD) factor, the most powerful aroma active compounds were safranal (FD = 512), 4-ketoisophorone (FD = 256) and dihydrooxophorone (FD = 128).

  11. Stochastic differential equation model to Prendiville processes

    NASA Astrophysics Data System (ADS)

    Granita, Bahar, Arifah

    2015-10-01

    The Prendiville process is another variation of the logistic model which assumes linearly decreasing population growth rate. It is a continuous time Markov chain (CTMC) taking integer values in the finite interval. The continuous time Markov chain can be approximated by stochastic differential equation (SDE). This paper discusses the stochastic differential equation of Prendiville process. The work started with the forward Kolmogorov equation in continuous time Markov chain of Prendiville process. Then it was formulated in the form of a central-difference approximation. The approximation was then used in Fokker-Planck equation in relation to the stochastic differential equation of the Prendiville process. The explicit solution of the Prendiville process was obtained from the stochastic differential equation. Therefore, the mean and variance function of the Prendiville process could be easily found from the explicit solution.

  12. Effect of cooking on aroma profile of red kidney beans (Phaseolus vulgaris) and correlation with sensory quality.

    PubMed

    Mishra, Prashant K; Tripathi, Jyoti; Gupta, Sumit; Variyar, Prasad S

    2017-01-15

    Volatile aroma compounds of three varieties of red kidney beans (Phaseolus vulgaris) namely Kashmiri red, Sharmili and Chitra were extracted in raw state using solid-phase microextraction (SPME) and cooked state using simultaneous distillation extraction (SDE). During cooking a significant (p<0.05) reduction in the content of several aldehydes, alcohols and terpene hydrocarbons while an increase in content of various sulfurous compounds, terpene alcohols, ketones and pyrazines was noted. Descriptive sensory analysis showed that the maximum intensity of 'kidney bean', 'earthy' and 'smoky' odour was observed in Kashmiri red while Sharmili variety was characterised by 'sulfurous' odour. Correlation of volatile profile data with descriptive sensory analysis and odour activity values clearly established the role of compounds, such as methanethiol, diethyl sulfide, dimethyl disulfide, methional and dimethyl trisulfide, in contributing to 'cooked kidney bean' aroma, while dimethyl sulfoxide, dimethyl sulfone and ethyl methyl sulfone were responsible for 'sulfurous' aroma.

  13. HYBRID SULFUR ELECROLYZER DEVELOPMENT, NHI WORK PACKAGE N-SR07TC0301, FY08 FIRST QUARTER REPORT

    SciTech Connect

    Summers, W

    2007-12-20

    Hydrogen has been identified as a leading candidate to replace petroleum as part of the transition to a sustainable energy system, and major efforts are being conducted worldwide to develop the technologies and supporting activities required for this transition. In the United States, the federal research efforts are led by the U.S. Department of Energy (DOE). The U.S. DOE Hydrogen Program is an integrated inter-office program being conducted by the Office of Energy Efficiency and Renewable Energy, Office of Nuclear Energy (DOE-NE), Office of Fossil Energy and Office of Science. The primary objective of the DOE-NE Nuclear Hydrogen Initiative (NHI) is to develop the nuclear hydrogen production technologies necessary to produce hydrogen at a cost competitive with other alternative transportation fuels. The focus of the NHI is on thermochemical cycles and high temperature electrolysis. The Savannah River National Laboratory (SRNL) has been tasked with the primary responsibility to perform research and development in order to characterize, evaluate and develop the Hybrid Sulfur (HyS) thermochemical process. The HyS Process uses a sulfur dioxide depolarized electrolyzer (SDE) to split water and produce hydrogen. During FY05 and FY06, SRNL designed and conducted proof-of-concept testing for a SDE using a low temperature, PEM fuel cell-type design concept. The advantages of this design concept include high electrochemical efficiency and small footprint, characteristics that are crucial for successful implementation on a commercial scale. During FY07, SRNL extended the range of testing of the SDE to higher temperature and pressure, conducted a 100-hour longevity test, and designed and built a larger, multi-cell stack electrolyzer. The proof of concept of SO2 electrolysis for the HyS Process is a priority research target for the FY 2008 NHI Program. Technical options must be better defined and the challenges better understood. The current status of electrolyzer performance

  14. How gauge covariance of the fermion and boson propagators in QED constrain the effective fermion-boson vertex

    NASA Astrophysics Data System (ADS)

    Jia, Shaoyang; Pennington, M. R.

    2016-12-01

    We derive the gauge covariance requirement imposed on the QED fermion-photon three-point function within the framework of a spectral representation for fermion propagators. When satisfied, such requirement ensures solutions to the fermion propagator Schwinger-Dyson equation (SDE) in any covariant gauge with arbitrary numbers of spacetime dimensions to be consistent with the Landau-Khalatnikov-Fradkin transformation (LKFT). The general result has been verified by the special cases of three and four dimensions. Additionally, we present the condition that ensures the vacuum polarization is independent of the gauge parameter. As an illustration, we show how the gauge technique dimensionally regularized in four dimensions does not satisfy the covariance requirement.

  15. Stochastic differential equation model to Prendiville processes

    SciTech Connect

    Granita; Bahar, Arifah

    2015-10-22

    The Prendiville process is another variation of the logistic model which assumes linearly decreasing population growth rate. It is a continuous time Markov chain (CTMC) taking integer values in the finite interval. The continuous time Markov chain can be approximated by stochastic differential equation (SDE). This paper discusses the stochastic differential equation of Prendiville process. The work started with the forward Kolmogorov equation in continuous time Markov chain of Prendiville process. Then it was formulated in the form of a central-difference approximation. The approximation was then used in Fokker-Planck equation in relation to the stochastic differential equation of the Prendiville process. The explicit solution of the Prendiville process was obtained from the stochastic differential equation. Therefore, the mean and variance function of the Prendiville process could be easily found from the explicit solution.

  16. How gauge covariance of the fermion and boson propagators in QED constrain the effective fermion-boson vertex

    SciTech Connect

    Jia, Shaoyang; Pennington, M. R.

    2016-12-12

    In this paper, we derive the gauge covariance requirement imposed on the QED fermion-photon three-point function within the framework of a spectral representation for fermion propagators. When satisfied, such requirement ensures solutions to the fermion propagator Schwinger-Dyson equation (SDE) in any covariant gauge with arbitrary numbers of spacetime dimensions to be consistent with the Landau-Khalatnikov-Fradkin transformation (LKFT). The general result has been verified by the special cases of three and four dimensions. Additionally, we present the condition that ensures the vacuum polarization is independent of the gauge parameter. Finally, as an illustration, we show how the gauge technique dimensionally regularized in four dimensions does not satisfy the covariance requirement.

  17. How gauge covariance of the fermion and boson propagators in QED constrain the effective fermion-boson vertex

    DOE PAGES

    Jia, Shaoyang; Pennington, M. R.

    2016-12-12

    In this paper, we derive the gauge covariance requirement imposed on the QED fermion-photon three-point function within the framework of a spectral representation for fermion propagators. When satisfied, such requirement ensures solutions to the fermion propagator Schwinger-Dyson equation (SDE) in any covariant gauge with arbitrary numbers of spacetime dimensions to be consistent with the Landau-Khalatnikov-Fradkin transformation (LKFT). The general result has been verified by the special cases of three and four dimensions. Additionally, we present the condition that ensures the vacuum polarization is independent of the gauge parameter. Finally, as an illustration, we show how the gauge technique dimensionally regularizedmore » in four dimensions does not satisfy the covariance requirement.« less

  18. Smart facility application: exploiting space technology for smart city solution

    NASA Astrophysics Data System (ADS)

    Termizi, A. A. A.; Ahmad, N.; Omar, M. F.; Wahap, N. A.; Zainal, D.; Ismail, N. M.

    2016-06-01

    Facilities and amenities management is amongst the core functionalities of local government. Considering the vast area that local government has to manage, a smart solution is extremely inevitable to solve issues such as inefficient maintenance of public parks, drainage system and so forth. Therefore, this paper aims to offer a smart city solution which exploits the benefit of space technology. This proposed solution is one of the modules developed in Spatial Smart City Service Delivery Engine (SSC SDE) Project undertaken by Agensi Angkasa Negara (ANGKASA). Various levels of local government have been chosen to understand real issues faced by them. Based on this data, a Smart Facility application has been developed with the aim to enhance the service delivery by the local government hence improving citizens’ satisfaction. Since this project is still in progress, this paper will merely discussing the concept of this application.

  19. Determination of volatile organic compounds, catechins, caffeine and theanine in Jukro tea at three growth stages by chromatographic and spectrometric methods.

    PubMed

    Jeon, Dong Bok; Hong, Young Shin; Lee, Ga Hyun; Park, Yu Min; Lee, Cheong Mi; Nho, Eun Yeong; Choi, Ji Yeon; Jamila, Nargis; Khan, Naeem; Kim, Kyong Su

    2017-03-15

    Tea contains characteristic volatile organic compounds, polyphenols, caffeine and catechins, and is therefore among the most widely consumed beverages all over the world. In this study, fresh Jukro tea leaves collected from Damyang-gun (Jeollanam-do) at 40, 60 and 90day growth stages, were semi-fermented. The volatile organic compounds (VOCs) were extracted by simultaneous distillation-solvent extraction (SDE) and analyzed by gas chromatography/mass spectrometry (GC/MS). Catechins, caffeine and theanine were analyzed by high performance liquid chromatography (HPLC). A total of 159 VOCs were identified in the analyzed Jukro tea leaves. Comparatively, the increase in the concentrations of VOCs was high in 60day leaves. The content of catechins increased along the three growth stages, whereas caffeine, compared to 90day leaves, was higher for 40 and 60day leaves. Based on the results, the 60day leaves were found to be the most suitable and useful for making semi-fermented Jukro tea.

  20. Complete Genome Sequence of the Complex Carbohydrate-Degrading Marine Bacterium, Saccharophagus degradans Strain 2-40T

    PubMed Central

    Weiner, Ronald M.; Taylor, Larry E.; Henrissat, Bernard; Hauser, Loren; Land, Miriam; Coutinho, Pedro M.; Rancurel, Corinne; Saunders, Elizabeth H.; Longmire, Atkinson G.; Zhang, Haitao; Bayer, Edward A.; Gilbert, Harry J.; Larimer, Frank; Zhulin, Igor B.; Ekborg, Nathan A.; Lamed, Raphael; Richardson, Paul M.; Borovok, Ilya; Hutcheson, Steven

    2008-01-01

    The marine bacterium Saccharophagus degradans strain 2-40 (Sde 2-40) is emerging as a vanguard of a recently discovered group of marine and estuarine bacteria that recycles complex polysaccharides. We report its complete genome sequence, analysis of which identifies an unusually large number of enzymes that degrade >10 complex polysaccharides. Not only is this an extraordinary range of catabolic capability, many of the enzymes exhibit unusual architecture including novel combinations of catalytic and substrate-binding modules. We hypothesize that many of these features are adaptations that facilitate depolymerization of complex polysaccharides in the marine environment. This is the first sequenced genome of a marine bacterium that can degrade plant cell walls, an important component of the carbon cycle that is not well-characterized in the marine environment. PMID:18516288

  1. Pre-sunrise uplift and sunrise downward excursion in the F-region vertical plasma drift: Observations from the mid-latitude station Nicosia

    NASA Astrophysics Data System (ADS)

    Mathew, Tiju Joseph; Haralambous, Haris; Oikonomou, Christina

    2017-04-01

    The characteristics of mid-latitude vertical plasma drift, with a focus on pre-sunrise hours for Nicosia station, Cyprus, based on digital ionosonde measurements, have been investigated and are reported for the first time. The pre-sunrise vertical plasma drift is defined by an uplift prior to sunrise, followed by a downward drift, which is referred to as sunrise downward excursion (SDE). The pre-sunrise uplift at mid-latitudes seems to be apparent due to 'thinning' of the F- layer bottom side. The observed uplift is followed by a sudden descend which is also 'apparent' and is attributed to the downward movement of the ionisation peak during sunrise. The pre-sunrise uplift is more significant in winter but the downward drift is observed irrespective of the season.

  2. Simulation and assimilation of satellite altimeter data at the oceanic mesoscale

    NASA Technical Reports Server (NTRS)

    Demay, P.; Robinson, A. R.

    1984-01-01

    An improved "objective analysis' technique is used along with an altimeter signal statistical model, an altimeter noise statistical model, an orbital model, and synoptic surface current maps in the POLYMODE-SDE area, to evaluate the performance of various observational strategies in catching the mesoscale variability at mid-latitudes. In particular, simulated repetitive nominal orbits of ERS-1, TOPEX, and SPOT/POSEIDON are examined. Results show the critical importance of existence of a subcycle, scanning in either direction. Moreover, long repeat cycles ( 20 days) and short cross-track distances ( 300 km) seem preferable, since they match mesoscale statistics. Another goal of the study is to prepare and discuss sea-surface height (SSH) assimilation in quasigeostrophic models. Restored SSH maps are shown to meet that purpose, if an efficient extrapolation method or deep in-situ data (floats) are used on the vertical to start and update the model.

  3. Research on sudden environmental pollution public service platform construction based on WebGIS

    NASA Astrophysics Data System (ADS)

    Bi, T. P.; Gao, D. Y.; Zhong, X. Y.

    2016-08-01

    In order to actualize the social sharing and service of the emergency-response information for sudden pollution accidents, the public can share the risk source information service, dangerous goods control technology service and so on, The SQL Server and ArcSDE software are used to establish a spatial database to restore all kinds of information including risk sources, hazardous chemicals and handling methods in case of accidents. Combined with Chinese atmospheric environmental assessment standards, the SCREEN3 atmospheric dispersion model and one-dimensional liquid diffusion model are established to realize the query of related information and the display of the diffusion effect under B/S structure. Based on the WebGIS technology, C#.Net language is used to develop the sudden environmental pollution public service platform. As a result, the public service platform can make risk assessments and provide the best emergency processing services.

  4. Geoscience information integration and visualization research of Shandong Province, China based on ArcGIS engine

    NASA Astrophysics Data System (ADS)

    Xu, Mingzhu; Gao, Zhiqiang; Ning, Jicai

    2014-10-01

    To improve the access efficiency of geoscience data, efficient data model and storage solutions should be used. Geoscience data is usually classified by format or coordinate system in existing storage solutions. When data is large, it is not conducive to search the geographic features. In this study, a geographical information integration system of Shandong province, China was developed based on the technology of ArcGIS Engine, .NET, and SQL Server. It uses Geodatabase spatial data model and ArcSDE to organize and store spatial and attribute data and establishes geoscience database of Shangdong. Seven function modules were designed: map browse, database and subject management, layer control, map query, spatial analysis and map symbolization. The system's characteristics of can be browsed and managed by geoscience subjects make the system convenient for geographic researchers and decision-making departments to use the data.

  5. A General Stochastic Maximum Principle for SDEs of Mean-field Type

    SciTech Connect

    Buckdahn, Rainer; Djehiche, Boualem; Li Juan

    2011-10-15

    We study the optimal control for stochastic differential equations (SDEs) of mean-field type, in which the coefficients depend on the state of the solution process as well as of its expected value. Moreover, the cost functional is also of mean-field type. This makes the control problem time inconsistent in the sense that the Bellman optimality principle does not hold. For a general action space a Peng's-type stochastic maximum principle (Peng, S.: SIAM J. Control Optim. 2(4), 966-979, 1990) is derived, specifying the necessary conditions for optimality. This maximum principle differs from the classical one in the sense that here the first order adjoint equation turns out to be a linear mean-field backward SDE, while the second order adjoint equation remains the same as in Peng's stochastic maximum principle.

  6. SURFACE PREPARATION OF STEEL SUBSTRATES USING GRIT-BLASTING

    SciTech Connect

    Donna Post Guillen; D. J. Varacalle, Jr.; D. Deason; W. Rhodaberger; E. Sampson

    2005-05-01

    The primary purpose of grit blasting for thermal spray applications is to ensure a strong mechanical bond between the substrate and the coating by the enhanced roughening of the substrate material. This study presents statistically designed experiments that were accomplished to investigate the effect of abrasives on roughness for A36/1020 steel. The experiments were conducted using a Box statistical design of experiment (SDE) approach. Three grit blasting parameters and their effect on the resultant substrate roughness were investigated. These include blast media, blast pressure, and working distance. The substrates were characterized for roughness using surface profilometry. These attributes were correlated with the changes in operating parameters. Twin-Wire Electric Arc (TWEA) coatings of aluminum and zinc/aluminum were deposited on the grit-blasted substrates. These coatings were then tested for bond strength. Bond strength studies were conducted utilizing a portable adhesion tester following ASTM standard D4541.

  7. Applying diffusion-based Markov chain Monte Carlo

    PubMed Central

    Paul, Rajib; Berliner, L. Mark

    2017-01-01

    We examine the performance of a strategy for Markov chain Monte Carlo (MCMC) developed by simulating a discrete approximation to a stochastic differential equation (SDE). We refer to the approach as diffusion MCMC. A variety of motivations for the approach are reviewed in the context of Bayesian analysis. In particular, implementation of diffusion MCMC is very simple to set-up, even in the presence of nonlinear models and non-conjugate priors. Also, it requires comparatively little problem-specific tuning. We implement the algorithm and assess its performance for both a test case and a glaciological application. Our results demonstrate that in some settings, diffusion MCMC is a faster alternative to a general Metropolis-Hastings algorithm. PMID:28301529

  8. Computer Automated Page Layout (PLA) for Text-Graphic Materials: User’s Guide.

    DTIC Science & Technology

    1982-12-01

    WRR4 Widt &,dk ?11*1 SPsoer (SeleCtOrd.0 0tions A Ad Sk file) btakww E(Siqtor V 0 [Oreu Bok 110) SFl$ (t *I i oject] 27 page 9 SEGMENT II: CREATING...015 0 a o o 0 16 0 0 0 0 0 17 0 0 0 0 0Page Input/Edt Choi : is 0 0 o 0 0 ’##’ Line ,1T’exti rint,1S’av,’.’ Done] Enter Desired Option: 01 Note...SI RE D) PROJECT: 4 . F :, t - PI35 Specify the BOOK< Reqired &ENWR OESIWD BOK C~#f r5. ’<y Po Ple,3SP SDeCifv the PAGEC Reuire NOs~ o<Nm,.r X Number

  9. Nonrelativistic Quantum Mechanics with Fundamental Environment

    NASA Astrophysics Data System (ADS)

    Gevorkyan, Ashot S.

    2011-03-01

    Spontaneous transitions between bound states of an atomic system, "Lamb Shift" of energy levels and many other phenomena in real nonrelativistic quantum systems are connected within the influence of the quantum vacuum fluctuations ( fundamental environment (FE)) which are impossible to consider in the limits of standard quantum-mechanical approaches. The joint system "quantum system (QS) + FE" is described in the framework of the stochastic differential equation (SDE) of Langevin-Schrödinger (L-Sch) type, and is defined on the extended space R 3 ⊗ R { ξ}, where R 3 and R { ξ} are the Euclidean and functional spaces, respectively. The density matrix for single QS in FE is defined. The entropy of QS entangled with FE is defined and investigated in detail. It is proved that as a result of interaction of QS with environment there arise structures of various topologies which are a new quantum property of the system.

  10. Quantum Harmonic Oscillator Subjected to Quantum Vacuum Fluctuations

    SciTech Connect

    Gevorkyan, A. S.; Burdik, C.; Oganesyan, K. B.

    2010-05-04

    Spontaneous transitions between bound states of an atomic system, 'Lamb Shift' of energy level, as well as many other phenomena in real nonrelativistic quantum systems are connected with the influence of quantum vacuum fluctuations which are impossible to consider in the limits of standard quantum-mechanical approaches. The joint system 'quantum harmonic oscillator (QHO)+ environment' is described in terms of complex probabilistic processes (CPP) which satisfies a stochastic differential equation (SDE) of Langevin-Schroedinger (L-Sch) type. On the basis of orthogonal CPP, the method of stochastic density matrix (SDM) is developed. The energy spectrum of QHO and a possibility of infringement of detailed balance of transitions between quantum levels including spontaneous decay of <> are investigated by the SDM method.

  11. Bayesian parameter inference for stochastic biochemical network models using particle Markov chain Monte Carlo

    PubMed Central

    Golightly, Andrew; Wilkinson, Darren J.

    2011-01-01

    Computational systems biology is concerned with the development of detailed mechanistic models of biological processes. Such models are often stochastic and analytically intractable, containing uncertain parameters that must be estimated from time course data. In this article, we consider the task of inferring the parameters of a stochastic kinetic model defined as a Markov (jump) process. Inference for the parameters of complex nonlinear multivariate stochastic process models is a challenging problem, but we find here that algorithms based on particle Markov chain Monte Carlo turn out to be a very effective computationally intensive approach to the problem. Approximations to the inferential model based on stochastic differential equations (SDEs) are considered, as well as improvements to the inference scheme that exploit the SDE structure. We apply the methodology to a Lotka–Volterra system and a prokaryotic auto-regulatory network. PMID:23226583

  12. TodK, a putative histidine protein kinase, regulates timing of fruiting body morphogenesis in Myxococcus xanthus.

    PubMed

    Rasmussen, Anders A; Søgaard-Andersen, Lotte

    2003-09-01

    In response to starvation, Myxococcus xanthus initiates a developmental program that results in the formation of spore-filled multicellular fruiting bodies. Fruiting body formation depends on the temporal and spatial coordination of aggregation and sporulation. These two processes are induced by the cell surface-associated C signal, with aggregation being induced after 6 h and sporulation being induced once cells have completed the aggregation process. We report the identification of TodK, a putative histidine protein kinase of two-component regulatory systems that is important for the correct timing of aggregation and sporulation. Loss of TodK function results in early aggregation and early, as well as increased levels of, sporulation. Transcription of todK decreases 10-fold in response to starvation independently of the stringent response. Loss of TodK function specifically results in increased expression of a subset of C-signal-dependent genes. Accelerated development in a todK mutant depends on the known components in the C-signal transduction pathway. TodK is not important for synthesis of the C signal. From these results we suggest that TodK is part of a signal transduction system which converges on the C-signal transduction pathway to negatively regulate aggregation, sporulation, and the expression of a subset of C-signal-dependent genes. TodK and the SdeK histidine protein kinase, which is part of a signal transduction system that converges on the C-signal transduction pathway to stimulate aggregation, sporulation, and C-signal-dependent gene expression, act in independent genetic pathways. We suggest that the signal transduction pathways defined by TodK and SdeK act in concert with the C-signal transduction pathway to control the timing of aggregation and sporulation.

  13. Hybrid Sulfur Thermochemical Process Development Annual Report

    SciTech Connect

    Summers, William A.; Buckner, Melvin R.

    2005-07-21

    The Hybrid Sulfur (HyS) Thermochemical Process is a means of producing hydrogen via water-splitting through a combination of chemical reactions and electrochemistry. Energy is supplied to the system as high temperature heat (approximately 900 C) and electricity. Advanced nuclear reactors (Generation IV) or central solar receivers can be the source of the primary energy. Large-scale hydrogen production based on this process could be a major contributor to meeting the needs of a hydrogen economy. This project's objectives include optimization of the HyS process design, analysis of technical issues and concerns, creation of a development plan, and laboratory-scale proof-of-concept testing. The key component of the HyS Process is the SO2-depolarized electrolyzer (SDE). Studies were performed that showed that an electrolyzer operating in the range of 500-600 mV per cell can lead to an overall HyS cycle efficiency in excess of 50%, which is superior to all other currently proposed thermochemical cycles. Economic analysis indicated hydrogen production costs of approximately $1.60 per kilogram for a mature nuclear hydrogen production plant. However, in order to meet commercialization goals, the electrolyzer should be capable of operating at high current density, have a long operating lifetime , and have an acceptable capital cost. The use of proton-exchange-membrane (PEM) technology, which leverages work for the development of PEM fuel cells, was selected as the most promising route to meeting these goals. The major accomplishments of this project were the design and construction of a suitable electrolyzer test facility and the proof-of-concept testing of a PEM-based SDE.

  14. Amplification of the snow melting effect on the heat wave over the Eurasia by absorbing aerosols

    NASA Astrophysics Data System (ADS)

    Kim, M. K.; Kim, K. M.; Lau, W. K. M.; Sang, J.; Yasunari, T. J.

    2015-12-01

    In this study, we present the potential impact of snow darkening effect on the Eurasian heat wave by absorbing aerosols using the NASA GEOS-5 Model experiments with aerosol tracers and a state-of-the-art snow darkening module for the land surface. Results show that snow darkening effect (SDE) can have a significant influence on not only the intensity but also the duration of heatwave during snow melting season, i.e., late spring season over the mid-western Eurasia and early summer season over the central northern Eurasia. During the early snow melting season surface air temperature is significantly increased by 3-6K due to early snow melting and enhanced solar radiation. Moreover enhanced evaporation induced by surface energy surplus during the early melting season leads to the new equilibrium level with lower soil moisture over the Eurasia since snow melting season, and thereby provide favorable condition for severe droughts and heat wave over the large parts of the Eurasia. This finding suggests that the SDE may play an important role in amplifying the snow melting effect on large-scale heat wave over the Eurasia. Energy and water balance at the surface supporting this findings are also discussed from evaporation-precipitation recycling point of view.

  15. Assessment of dose reconstruction errors in image-guided radiation therapy

    PubMed Central

    Zhong, Hualiang; Weiss, Elisabeth; Siebers, Jeffrey V

    2010-01-01

    Dose reconstruction can be used to improve the accuracy of dose evaluation throughout a treatment course. Its working mechanism is based on deformable image registration (DIR). The purpose of this paper is to develop a method to estimate the dose reconstruction error associated with the inaccuracy of DIR algorithms. To reach this goal, we quantified dominant errors in DIR in terms of unbalanced energy (UE), which were compared with the standard displacement error (SDE). Their high similarity, characterized by Pearson correlation coefficient, was verified through nine ‘demons’ registration instances performed within simulated reference frames. Based on the similarity, the dose-warping discrepancy at each voxel was defined as a line integral of the dose gradient within the voxel's neighborhood whose boundary was determined by the voxel's UE value. From this definition, the dose reconstruction error was then calculated at each voxel on nine prostate computed tomography images, obtained from a patient treatment course. The average of the Pearson correlation coefficients between UE and SDE over the simulated registration instances was above 70%. The mean value of the dose reconstruction errors in a target volume was calculated for each of nine treatment fractions. The averaged percentage of these mean values with respect to the prescribed dose on the target volume was 1.68%. These results are consistent with contour-based mean dose error evaluations. This paper has established a relation between a registration error and its induced dose reconstruction discrepancy. It allows an automatic validation method to be developed to estimate the dose accumulation error at each voxel in clinical settings. PMID:18199911

  16. Characterization of the key aroma compounds in Turkish olive oils from different geographic origins by application of aroma extract dilution analysis (AEDA).

    PubMed

    Kesen, Songul; Kelebek, Hasim; Selli, Serkan

    2014-01-15

    The aroma and aroma-active compounds of olive oils obtained from Nizip Yaglik (NY) and Kilis Yaglik (KY) cultivars and the effect of the geographical area (southern Anatolian and Aegean regions) on these compounds were analyzed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O). For this purpose, two oil samples were obtained from their native geographical area including NY from Nizip province and KY from Kilis province (southern Anatolian region of Turkey). Another two oils of the same cultivar, NY-Bornova (NY-B) and KY-Bornova (KY-B), were obtained from the Olive Oil Research Center-Bornova, Izmir province (Aegean region of Turkey) to compare geographical effect on aroma and aroma-active compounds. Simultaneous distillation and extraction (SDE) with dichloromethane was used for extraction of volatile components. SDE gave a highly representative aromatic extract of the studied olive oil based on the sensory analysis. Totals of 61, 48, 59, and 48 aroma compounds were identified and quantified in olive oils obtained from NY, NY-B, KY, and KY-B cultivars, respectively. The results of principal component analysis (PCA) showed that the aroma profile of native region oils was discriminately different from those of Bornova region oils. Aldehydes and alcohols were qualitatively and quantitatively the most dominant volatiles in the oil samples. Aroma extract dilution analysis (AEDA) was used for the determination of aroma-active compounds of olive oils. The number of aroma-active compounds in native region oils was higher than in Bornova region oils. Within the compounds, aldehydes and alcohols were the largest aroma-active compounds in all olive oils.

  17. Process optimizations to recessed e-SiGe source/drain for performance enhancement in 22 nm all-last high-k/metal-gate pMOSFETs

    NASA Astrophysics Data System (ADS)

    Qin, Changliang; Wang, Guilei; Hong, Peizhen; Liu, Jinbiao; Yin, Huaxiang; Yin, Haizhou; Ma, Xiaolong; Cui, Hushan; Lu, Yihong; Meng, Lingkuan; Xiang, Jinjuan; Zhong, Huicai; Zhu, Huilong; Xu, Qiuxia; Li, Junfeng; Yan, Jian; Zhao, Chao; Radamson, Henry H.

    2016-09-01

    In this paper, the technology of recessed embedded SiGe (e-SiGe) source/drain (S/D) module is optimized for the performance enhancement in 22 nm all-last high-k/metal-gate (HK/MG) pMOSFETs. Different Si recess-etch techniques were applied in S/D regions to increase the strain in the channel and subsequently, improve the performance of transistors. A new recess-etch method consists of a two-step etch method is proposed. This process is an initial anisotropic etch for the formation of shallow trench followed by a final isotropic etch. By introducing the definition of the upper edge distance (D) between the recessed S/D region and the channel region, the process advantage of the new approach is clearly presented. It decreases the value of D than those by conventional one-step isotropic or anisotropic etch of Si. Therefore, the series resistance is reduced and the channel strain is increased, which confirmed by the simulation results. The physical reason of D reducing is analyzed in brief. Applying this recess design, the implant conditions for S/D extension (SDE) are also optimized by using a two-step implantation of BF2 in SiGe layers. The overlap space between doping junction and channel region has great effect on the device's performance. The designed implantation profile decreases the overlap space while keeps a shallow junction depth for a controllable short channel effect. The channel resistance as well as the transfer ID-VG curves varying with different process conditions are demonstrated. It shows the drive current of the device with the optimized SDE implant condition and Si recess-etch process is obviously improved. The change trend of on-off current distributions extracted from a series of devices confirmed the conclusions. This study provides a useful guideline for developing high performance strained PMOS SiGe technology.

  18. Construction of the landscape for multi-stable systems: Potential landscape, quasi-potential, A-type integral and beyond

    NASA Astrophysics Data System (ADS)

    Zhou, Peijie; Li, Tiejun

    2016-03-01

    Motivated by the famous Waddington's epigenetic landscape metaphor in developmental biology, biophysicists and applied mathematicians made different proposals to construct the landscape for multi-stable complex systems. We aim to summarize and elucidate the relationships among these theories from a mathematical point of view. We systematically investigate and compare three different but closely related realizations in the recent literature: the Wang's potential landscape theory from steady state distribution of stochastic differential equations (SDEs), the Freidlin-Wentzell quasi-potential from the large deviation theory, and the construction through SDE decomposition and A-type integral. We revisit that the quasi-potential is the zero noise limit of the potential landscape, and the potential function in the third proposal coincides with the quasi-potential. We compare the difference between local and global quasi-potential through the viewpoint of exchange of limit order for time and noise amplitude. We argue that local quasi-potentials are responsible for getting transition rates between neighboring stable states, while the global quasi-potential mainly characterizes the residence time of the states as the system reaches stationarity. The difference between these two is prominent when the transitivity property is broken. The most probable transition path by minimizing the Onsager-Machlup or Freidlin-Wentzell action functional is also discussed. As a consequence of the established connections among different proposals, we arrive at the novel result which guarantees the existence of SDE decomposition while denies its uniqueness in general cases. It is, therefore, clarified that the A-type integral is more appropriate to be applied to the decomposed SDEs rather than its primitive form as believed by previous researchers. Our results contribute to a deeper understanding of landscape theories for biological systems.

  19. Ice nuclei properties within a Saharan dust event at the Jungfraujoch in the Swiss Alps

    NASA Astrophysics Data System (ADS)

    Chou, C.; Stetzer, O.; Weingartner, E.; Jurányi, Z.; Kanji, Z. A.; Lohmann, U.

    2011-05-01

    The new portable ice nucleation chamber (PINC) developed by the Institute for Atmospheric and Climate Sciences of ETH Zurich was operated during two measurement campaigns at the high alpine research station Jungfraujoch situated at 3580 m a.s.l, in March and June 2009. During this time of the year, a high probability of Saharan dust events (SDE) at the Jungfraujoch has been observed. We used an impactor with a cutoff size of 1 μm aerodynamic diameter and operated the system at -31 °C and relative humidities of 127 % and 91 % with respect to ice and water, respectively. Investigation of the ambient number concentration of ice nuclei (IN) in the deposition nucleation mode and during a SDE in the free troposphere is reported. The results discussed in this paper are the first continuous IN measurements over a period of several days at the Jungfraujoch. The average IN concentration found during the campaign in March was 8 particles per liter whereas during the campaign in June, the average number concentration was higher up to 14 particles per liter. Two SDEs were detected on 15 and 16 June 2009. Our measurements show that the SDEs had IN number concentration up to several hundreds per liter. We found the best correlation between the number concentration of the larger particle fraction measured by an optical particle counter and the IN number concentration during a Saharan dust event. This correlation factor is higher for particles larger than 0.5 μm meaning that a higher concentration of larger particles induced higher IN number concentration. No correlation could be found between the black carbon mass concentration and the variations in IN number concentration.

  20. Ice nuclei properties within a Saharan Dust Event at the Jungfraujoch

    NASA Astrophysics Data System (ADS)

    Chou, C.; Stetzer, O.; Weingartner, E.; Jurányi, Z.; Kanji, Z. A.; Lohmann, U.

    2010-10-01

    The new portable ice nucleation chamber (PINC) developed by the Institute for Atmospheric and Climate Sciences of ETH Zurich was operated during two campaigns PINC II and III at the high alpine research station Jungfraujoch situated at 3580 m a.s.l., in March and June 2009, respectively. During this time of the year, a high probability of Saharan Dust Events (SDE) at the Jungfraujoch has been observed. We used an impactor with a cutoff size of 1 μm aerodynamic diameter and operated the system at -31 °C and relative humidities of 127% and 91% with respect to ice and water, respectively in order to investigate the contribution of deposition freezing to mixed-phase clouds and also to look at the number concentration of ice nuclei (IN) during a SDE. The average IN concentration during PINC II was 8 particles per liter whereas during PINC III, the average number concentration was higher up to 14 particles per liter. Two SDEs were detected on 15 and 16 June 2009. Our measurements show that the SDEs had IN number concentration up to several hundreds per liter. We found the best correlation between the number concentration of the larger particle fraction measured by an optical particle counter and the IN number concentration during a Saharan Dust Event. This correlation factor is higher for particles larger than 0.5 μm meaning that a higher concentration of larger particles induced higher IN number concentration. No correlation could be found between the black carbon mass concentration and the variations in IN number concentration.

  1. EVALUATION OF PROTON-CONDUCTING MEMBRANES FOR USE IN A SULFUR-DIOXIDE DEPOLARIZED ELECTROLYZER

    SciTech Connect

    Hobbs, D.; Elvington, M.; Colon-Mercado, H.

    2009-11-11

    The chemical stability, sulfur dioxide transport, ionic conductivity, and electrolyzer performance have been measured for several commercially available and experimental proton exchange membranes (PEMs) for use in a sulfur dioxide depolarized electrolyzer (SDE). The SDE's function is to produce hydrogen by using the Hybrid Sulfur (HyS) Process, a sulfur based electrochemical/thermochemical hybrid cycle. Membrane stability was evaluated using a screening process where each candidate PEM was heated at 80 C in 60 wt. % H{sub 2}SO{sub 4} for 24 hours. Following acid exposure, chemical stability for each membrane was evaluated by FTIR using the ATR sampling technique. Membrane SO{sub 2} transport was evaluated using a two-chamber permeation cell. SO{sub 2} was introduced into one chamber whereupon SO{sub 2} transported across the membrane into the other chamber and oxidized to H{sub 2}SO{sub 4} at an anode positioned immediately adjacent to the membrane. The resulting current was used to determine the SO{sub 2} flux and SO{sub 2} transport. Additionally, membrane electrode assemblies (MEAs) were prepared from candidate membranes to evaluate ionic conductivity and selectivity (ionic conductivity vs. SO{sub 2} transport) which can serve as a tool for selecting membranes. MEAs were also performance tested in a HyS electrolyzer measuring current density versus a constant cell voltage (1V, 80 C in SO{sub 2} saturated 30 wt% H2SO{sub 4}). Finally, candidate membranes were evaluated considering all measured parameters including SO{sub 2} flux, SO{sub 2} transport, ionic conductivity, HyS electrolyzer performance, and membrane stability. Candidate membranes included both PFSA and non-PFSA polymers and polymer blends of which the non-PFSA polymers, BPVE-6F and PBI, showed the best selectivity.

  2. Systematic analysis of the regulatory functions of microRNAs in chicken hepatic lipid metabolism

    PubMed Central

    Li, Hong; Ma, Zheng; Jia, Lijuan; Li, Yanmin; Xu, Chunlin; Wang, Taian; Han, Ruili; Jiang, Ruirui; Li, Zhuanjian; Sun, Guirong; Kang, Xiangtao; Liu, Xiaojun

    2016-01-01

    Laying performance is an important economic trait in hens, and this physiological process is largely influenced by the liver function. The livers of hens at 20- and 30-week-old stages were investigated using the next generation sequencing to identify the differences of microRNA expression profiles. Compared with the 20-week-old hens, 67 down- and 13 up-regulated microRNAs were verified to be significant differentially expressed (false discovery rate, FDR ≤ 0.05) (SDE) in the 30-week-old. We also identified 13 down- and 6 up-regulated novel differentially expressed (DE) microRNAs. miR-22-3p and miR-146b-5p, which exhibit critical roles in mammalian lipid metabolism, showed the most abundant expression and the highest fold-change, respectively. A total of 648 potential target genes of the SDE microRNAs were identified through an integrated analysis of microRNAs and the DE genes obtained in previous RNA-sequencing, including FADS1, FADS2, ELOVL6 and ACSL5, which are critical lipid metabolism-related regulators. Bioinformatic analyses revealed that target genes were mainly enriched in lipid-related metabolism processes. This work provides the first study of the expression patterns of hepatic microRNAs between 20- and 30-week old hens. The findings may serve as a fundamental resource for understanding the detailed functions of microRNAs in the molecular regulatory systems of lipid metabolism. PMID:27535581

  3. Characterization Testing of H20-SO2 Electrolyzer at Ambient Pressure

    SciTech Connect

    Steimke, J

    2005-07-29

    This document reports work performed at the Savannah River National Laboratory (SRNL) that resulted in a major accomplishment by demonstrating the proof-of-concept of the use of a proton exchange membrane or PEM-type electrochemical cell to produce hydrogen via SO{sub 2}-depolarized water electrolysis. For the first time sulfur dioxide dissolved in liquid sulfuric acid was used to depolarize water electrolysis in a modern PEM cell. The use of such a cell represents a major step in achieving the ultimate goal of an economical hydrogen production process based on the Hybrid Sulfur (HyS) Cycle. The HyS Process is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by water-splitting. Like all other sulfur-based cycles, HyS utilizes the high temperature thermal decomposition of sulfuric acid to produce oxygen. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Sulfur dioxide is oxidized at the anode, producing sulfuric acid, that is sent to the acid decomposition portion of the cycle. The focus of this work was to conduct single cell electrolyzer tests in order to prove the concept of SO{sub 2}-depolarization and to determine how the results can be used to evaluate the performance of key components of the HyS Process. A test facility for conducting SO{sub 2}-depolarized electrolyzer (SDE) testing was designed, constructed and commissioned. The maximum cell current is 50 amperes, which is equivalent to a hydrogen production rate of approximately 20 liters per hour. The test facility was designed for operation at room temperature with pressures up to 2 bar. Feed to the anode of the electrolyzer can be water, sulfuric acid of various concentrations, or sulfuric acid containing dissolved sulfur dioxide. Provisions

  4. A clerking tool for the patient record system.

    PubMed

    McDermott, D; Heathfield, H; Kirby, J

    1995-01-01

    1. BACKGROUND. The goal of the PEN&PAD (Elderly Care) project is to develop a patient record system to assist the many different professionals that care for patients in a hospital setting. At the core of the project is the use of structured data which can be reused in a variety of ways--both within the system for further manipulation and display, and externally for auditing and statistical purposes. To accommodate these needs, a compositional method of data entry called Structured Data Entry (SDE) was used in this application. SDE was developed in an earlier project PEN&PAD (GP)(1). Our application utilizes a network representation of the medical semantics that can be queried to obtain what is sensible to "say" about a particular concept. This functionality is contained within a separate application known as the Terminology Server (TeS), which has been developed within the GALEN project (2). The client application (the patient record system) requests information from the TeS which can then be used to produce compositional data entry forms that require the user to choose values for given attributes (e.g., if information pertaining to chest pain were being recorded, the attribute 'location' and a choice of possible values i.e., 'left' 'right' and 'bilateral' might appear on the form). Given the importance of capturing clinical information in a highly structured format, SDE is a valuable tool. However, its long term success depends on a very comprehensive model of the medical terminology corpus. This component is currently being studied by the GALEN team. 2. CURRENT WORK. We are developing a clerking tool to be used to create records for the newly admitted patient. The clinician seeks to identify a patient's problems based on physical examination and information obtained through conversation with the patient. Patients are usually admitted with a presenting complaint and obtaining more information about this complaint is an important part of the clerking process. While

  5. Understanding and Predicting Geomagnetic Dipole Reversals Via Low Dimensional Models and Data Assimilation

    NASA Astrophysics Data System (ADS)

    Morzfeld, M.; Fournier, A.; Hulot, G.

    2014-12-01

    We investigate the geophysical relevance of low-dimensional models of the geomagnetic dipole fieldby comparing these models to the signed relative paleomagnetic intensity over the past 2 Myr.The comparison is done via Bayesian statistics, implemented numerically by Monte Carlo (MC) sampling.We consider several MC schemes, as well as two data sets to show the robustness of our approach with respect to its numerical implementation and to the details of how the data are collected.The data we consider are the Sint-2000 [1] and PADM2M [2] data sets.We consider three stochastic differential equation (SDE) models and one deterministic model. Experiments with synthetic data show that it is feasible that a low dimensional modelcan learn the geophysical state from data of only the dipole field,and reveal the limitations of the low-dimensional models.For example, the G12 model [3] (a deterministic model that generates dipole reversals by crisis induced intermittency)can only match either one of the two important time scales we find in the data. The MC sampling approach also allows usto use the models to make predictions of the dipole field.We assess how reliably dipole reversals can be predictedwith our approach by hind-casting five reversals documented over the past 2 Myr. We find that, besides its limitations, G12 can be used to predict reversals reliably,however only with short lead times and over short horizons. The scalar SDE models on the other hand are not useful for prediction of dipole reversals.References Valet, J.P., Maynadier,L and Guyodo, Y., 2005, Geomagnetic field strength and reversal rate over the past 2 Million years, Nature, 435, 802-805. Ziegler, L.B., Constable, C.G., Johnson, C.L. and Tauxe, L., 2011, PADM2M: a penalized maximum likelihood model of the 0-2 Ma paleomagnetic axial dipole moment, Geophysical Journal International, 184, 1069-1089. Gissinger, C., 2012, A new deterministic model for chaotic reversals, European Physical Journal B, 85:137.

  6. A Newly Emerged Cutaneous Leishmaniasis Focus in Northern Israel and Two New Reservoir Hosts of Leishmania major

    PubMed Central

    Faiman, Roy; Abbasi, Ibrahim; Jaffe, Charles; Motro, Yoav; Nasereddin, Abdelmagid; Schnur, Lionel F.; Torem, Moshe; Pratlong, Francine; Dedet, Jean-Pierre; Warburg, Alon

    2013-01-01

    In 2006/7, 18 cases of cutaneous leishmaniasis (CL) were reported for the first time from Sde Eliyahu (pop. 650), a village in the Beit She'an valley of Israel. Between 2007–2011, a further 88 CL cases were diagnosed bringing the total to 106 (16.3% of the population of Sde Eliyahu). The majority of cases resided in the south-western part of the village along the perimeter fence. The causative parasite was identified as Leishmania major Yakimoff & Schokhor, 1914 (Kinetoplastida: Trypanosomatidae). Phlebotomus papatasi (Scopoli), 1786 (Diptera: Psychodidae) was found to be the most abundant phlebotomine species comprising 97% of the sand flies trapped inside the village, and an average of 7.9% of the females were positive for Leishmania ITS1 DNA. Parasite isolates from CL cases and a sand fly were characterized using several methods and shown to be L. major. During a comprehensive survey of rodents 164 Levant voles Microtus guentheri Danford & Alston, 1880 (Rodentia: Cricetidae) were captured in alfalfa fields bordering the village. Of these 27 (16.5%) tested positive for Leishmania ITS1 DNA and shown to be L. major by reverse line blotting. A very high percentage (58.3% - 21/36) of Tristram's jirds Meriones tristrami Thomas, 1892 (Rodentia: Muridae), found further away from the village also tested positive for ITS1 by PCR. Isolates of L. major were successfully cultured from the ear of a wild jird found positive by ITS1 PCR. Although none of the wild PCR-positive voles exhibited external pathology, laboratory-reared voles that were infected by intradermal L. major inoculation, developed patent lesions and sand flies became infected by feeding on the ears of these laboratory-infected voles. This is the first report implicating M. guentheri and M. tristrami as reservoirs of Leishmania. The widespread co-distribution of M. guentheri and P. papatasi, suggests a significant threat from the spread of CL caused by L. major in the Middle East, central Asia and southern

  7. HYBRID SULFUR ELECTROLYZER DEVELOPMENT, NHI WORK PACKAGE N-SR07TC0301, FY07 FIRST QUARTER REPORT

    SciTech Connect

    Summers, W

    2006-12-20

    The proof of concept of SO2 electrolysis for the hybrid sulfur (HyS) process is the second priority research target of the DOE Nuclear Hydrogen Initiative's thermochemical program for FY07. The proof of concept of the liquid-phase option must be demonstrated at the single cell level for an extended run times (>100 hours). The rate of development of HyS will depend on the identification of a promising membrane or an alternative means for controlling sulfur formation. Once successful long-duration operation has been demonstrated, SRNL will develop a multi-cell stack that can be connected to the H2SO4 decomposer being developed by SNL for the S-I ILS for a Hybrid Sulfur Integrated Laboratory-Scale Experiment during FY 2008. During the first quarter of FY07, SRNL continued the component development and membrane development activities with the goal of identifying and characterizing improved electrodes, electrocatalysts, membranes and MEA configurations which could then be tested at larger scale in the SDE test facility. A modified glass cell was fabricated to allow measurements of sulfur dioxide (SO2) transport across membrane samples at elevated temperatures (up to 70 C). This testing also includes evaluating SO2 transport in different sulfuric acid concentrations (30-70 wt%). A new potentiostat/frequency analyzer was installed for determining ionic conductivity of membranes. This instrument enhances our capabilities to characterize membrane, electrocatalyst and MEA properties and performance. Continuing work from FY06, evaluations were preformed on various commercial and experimental membranes and electrocatalyst materials for the SDE. Several different types of commercially-available membranes were analyzed for sulfur dioxide transport as a function of acid strength including perfluorinated sulfonic acid (PFSA), sulfonated polyetherketone-ketone, and poly-benzimidazole (PBI) membranes. Experimental membranes from the sulfonated diels-alder polyphenylenes (SDAPP) and

  8. Generic method for automatic bladder segmentation on cone beam CT using a patient-specific bladder shape model

    SciTech Connect

    Schoot, A. J. A. J. van de Schooneveldt, G.; Wognum, S.; Stalpers, L. J. A.; Rasch, C. R. N.; Bel, A.; Hoogeman, M. S.; Chai, X.

    2014-03-15

    Purpose: The aim of this study is to develop and validate a generic method for automatic bladder segmentation on cone beam computed tomography (CBCT), independent of gender and treatment position (prone or supine), using only pretreatment imaging data. Methods: Data of 20 patients, treated for tumors in the pelvic region with the entire bladder visible on CT and CBCT, were divided into four equally sized groups based on gender and treatment position. The full and empty bladder contour, that can be acquired with pretreatment CT imaging, were used to generate a patient-specific bladder shape model. This model was used to guide the segmentation process on CBCT. To obtain the bladder segmentation, the reference bladder contour was deformed iteratively by maximizing the cross-correlation between directional grey value gradients over the reference and CBCT bladder edge. To overcome incorrect segmentations caused by CBCT image artifacts, automatic adaptations were implemented. Moreover, locally incorrect segmentations could be adapted manually. After each adapted segmentation, the bladder shape model was expanded and new shape patterns were calculated for following segmentations. All available CBCTs were used to validate the segmentation algorithm. The bladder segmentations were validated by comparison with the manual delineations and the segmentation performance was quantified using the Dice similarity coefficient (DSC), surface distance error (SDE) and SD of contour-to-contour distances. Also, bladder volumes obtained by manual delineations and segmentations were compared using a Bland-Altman error analysis. Results: The mean DSC, mean SDE, and mean SD of contour-to-contour distances between segmentations and manual delineations were 0.87, 0.27 cm and 0.22 cm (female, prone), 0.85, 0.28 cm and 0.22 cm (female, supine), 0.89, 0.21 cm and 0.17 cm (male, supine) and 0.88, 0.23 cm and 0.17 cm (male, prone), respectively. Manual local adaptations improved the segmentation

  9. Study of pulsed signals in UV spectra lines of free atmosphere above Novolazarevskaya station (Antarctica): effect of the solar irradiance?

    NASA Astrophysics Data System (ADS)

    Troshichev, Oleg; Shapovalov, Sergey; Lozovsky, Vladimir

    Study of pulsed signals in UV spectra lines of free atmosphere above Registration of the pulsed signals in zenith of free atmosphere (in range 300-400 nm) was carried out by spectrometer AvaSpec-2048 under the technogenically clear conditions at the Antarctic station Novolazarevskaya. The pulsed signals, with jumps in frequency exceeding by order or more the standard deviation, have been found in five lines, lied in the UV range: 332 nm, 333.5 nm, 342.5 nm, 351.5 nm and 395.2nm. The pulsed signals at the indicated frequencies can be of opposed polarity (the power increases and decreases) with value adequate to the energetic jumps from 0.01 ¨ˆ 0.04 eV/photons. These pulsed signals were compared aı with variations at the appropriate frequencies 331.9 nm, 333.4 nm, 342.5 nm, 351.4 nm and 395.4 nm observed by spectrometer on board the SORCE spacecraft. The certain consistency in the time behavior of values of the mean daily energy standard deviations taking place at Novolazarevskaya (SDE A ) and in SORCE experiment (SDSSI ) has been revealed when passing from the (local) winter to summer conditions (September 01, 2005 to December 17, 2005). The best correlation between pulsed signals detected in the atmospheric and extra-atmospheric conditions is for frequency 333,5 nm. On the other hand, the temporal changes of SDE A for frequency interval 329.5 - 334 nm are consistent with variations in ozone content, measured simultaneously at Novolazarevskya station. Conclusion is made that occurrence of the pulsed signals in UV spectra is of regular character and seems to be related to processes in the Sun. Nevertheless the run of the pulses number turned out to be imperfectly correlated with behavior of the different characteristic of the solar activity. That is why it was suggested that pulsed signals are related to some unknown irradiation, which either takes origin within the Sun or guided by the solar activity. It is suggested that the Earth is constantly exposed to action

  10. Effect of application of dairy manure, effluent and inorganic fertilizer on nitrogen leaching in clayey fluvo-aquic soil: A lysimeter study.

    PubMed

    Fan, Jianling; Xiao, Jiao; Liu, Deyan; Ye, Guiping; Luo, Jiafa; Houlbrooke, David; Laurenson, Seth; Yan, Jing; Chen, Lvjun; Tian, Jinping; Ding, Weixin

    2017-08-15

    Dairy farm manure and effluent are applied to cropland in China to provide a source of plant nutrients, but there are concerns over its effect on nitrogen (N) leaching loss and groundwater quality. To investigate the effects of land application of dairy manure and effluent on potential N leaching loss, two lysimeter trials were set up in clayey fluvo-aquic soil in a winter wheat-summer maize rotation cropping system on the North China Plain. The solid dairy manure trial included control without N fertilization (CK), inorganic N fertilizer (SNPK), and fresh (RAW) and composted (COM) dairy manure. The liquid dairy effluent trial consisted of control without N fertilization (CF), inorganic N fertilizer (ENPK), and fresh (FDE) and stored (SDE) dairy effluent. The N application rate was 225kgNha(-1) for inorganic N fertilizer, dairy manure, and effluent treatments in both seasons. Annual N leaching loss (ANLL) was highest in SNPK (53.02 and 16.21kgNha(-1) in 2013/2014 and 2014/2015, respectively), which were 1.65- and 2.04-fold that of COM, and 1.59- and 1.26-fold that of RAW. In the effluent trial (2014/2015), ANLL for ENPK and SDE (16.22 and 16.86kgNha(-1), respectively) were significantly higher than CF and FDE (6.3 and 13.21kgNha(-1), respectively). NO3(-) contributed the most (34-92%) to total N leaching loss among all treatments, followed by dissolved organic N (14-57%). COM showed the lowest N leaching loss due to a reduction in NO3(-) loss. Yield-scaled N leaching in COM (0.35kgNMg(-1) silage) was significantly (P<0.05) lower than that in the other fertilization treatments. Therefore, the use of composted dairy manure should be increased and that of inorganic fertilizer decreased to reduce N leaching loss while ensuring high crop yield in the North China Plain.

  11. Seamless Digital Environment – Plan for Data Analytics Use Case Study

    SciTech Connect

    Oxstrand, Johanna; Bly, Aaron

    2016-09-01

    The U.S Department of Energy Light Water Reactor Sustainability (LWRS) Program initiated research in to what is needed in order to provide a roadmap or model for Nuclear Power Plants to reference when building an architecture that can support the growing data supply and demand flowing through their networks. The Digital Architecture project published report Digital Architecture Planning Model (Oxstrand et. al, 2016) discusses things to consider when building an architecture to support the increasing needs and demands of data throughout the plant. Once the plant is able to support the data demands it still needs to be able to provide the data in an easy, quick and reliable method. A common method is to create a “one stop shop” application that a user can go to get all the data they need. The creation of this leads to the need of creating a Seamless Digital Environment (SDE) to integrate all the “siloed” data. An SDE is the desired perception that should be presented to users by gathering the data from any data source (e.g., legacy applications and work management systems) without effort by the user. The goal for FY16 was to complete a feasibility study for data mining and analytics for employing information from computer-based procedures enabled technologies for use in developing improved business analytics. The research team collaborated with multiple organizations to identify use cases or scenarios, which could be beneficial to investigate in a feasibility study. Many interesting potential use cases were identified throughout the FY16 activity. Unfortunately, due to factors out of the research team’s control, none of the studies were initiated this year. However, the insights gained and the relationships built with both PVNGS and NextAxiom will be valuable when moving forward with future research. During the 2016 annual Nuclear Information Technology Strategic Leadership (NITSL) group meeting it was identified would be very beneficial to the industry to

  12. CLOSE-OUT REPORT FOR HYS ELECTROLYZER COMPONENT DEVELOPMENT WORK AT SAVANNAH RIVER NATIONAL LABORATORY

    SciTech Connect

    Colon-Mercado, H.; Elvington, M.; Hobbs, D.

    2010-01-20

    The chemical stability, sulfur dioxide transport, ionic conductivity, and electrolyzer performance have been measured for several commercially available and experimental proton exchange membranes (PEMs) for use in a sulfur dioxide depolarized electrolyzer (SDE). The SDE's function is to produce hydrogen by using the Hybrid Sulfur (HyS) Process, a sulfur based electrochemical/thermochemical hybrid cycle. Membrane stability was evaluated using a screening process where each candidate PEM was heated at 80 C in 63.5 wt. % H{sub 2}SO{sub 4} for 24 hours. Following acid exposure, chemical stability for each membrane was evaluated by FTIR using the ATR sampling technique. Membrane SO{sub 2} transport was evaluated using a two-chamber permeation cell. SO{sub 2} was introduced into one chamber whereupon SO{sub 2} transported across the membrane into the other chamber and oxidized to H{sub 2}SO{sub 4} at an anode positioned immediately adjacent to the membrane. The resulting current was used to determine the SO{sub 2} flux and SO{sub 2} transport. Additionally, membrane electrode assemblies (MEAs) were prepared from candidate membranes to evaluate ionic conductivity and selectivity (ionic conductivity vs. SO{sub 2} transport) which can serve as a tool for selecting membranes. MEAs were also performance tested in a HyS electrolyzer measuring current density versus a constant cell voltage (1V, 80 C in SO{sub 2} saturated 30 wt% H{sub 2}SO{sub 4}). Finally, candidate membranes were evaluated considering all measured parameters including SO{sub 2} flux, SO{sub 2} transport, ionic conductivity, HyS electrolyzer performance, and membrane stability. Candidate membranes included both PFSA and non-PFSA polymers and polymer blends of which the non-PFSA polymers, BPVE-6F and PBI, showed the best selectivity. Testing examined the activity for the sulfur dioxide oxidation of platinum base electrocatalyst in 30 wt% sulfuric acid solution. Linear sweep voltammetry showed an increase in

  13. Effects of gamma irradiation on the yields of volatile extracts of Angelica gigas Nakai

    NASA Astrophysics Data System (ADS)

    Seo, Hye-Young; Kim, Jun-Hyoung; Song, Hyun-Pa; Kim, Dong-Ho; Byun, Myung-Woo; Kwon, Joog-Ho; Kim, Kyong-Su

    2007-11-01

    The study was carried out to determine the effects of gamma irradiation on the volatile flavor components including essential oils, of Angelica gigas Nakai. The volatile organic compounds from non- and irradiated A. gigas Nakai at doses of 1, 3, 5, 10 and 20 kGy were extracted by a simultaneous steam distillation and extraction (SDE) method and identified by GC/MS analysis. A total of 116 compounds were identified and quantified from non- and irradiated A. gigas Nakai. The major volatile compounds were identified 2,4,6-trimethyl heptane, α-pinene, camphene, α-limonene, β-eudesmol, α-murrolene and sphatulenol. Among these compounds, the amount of essential oils in non-irradiated sample were 77.13%, and the irradiated samples at doses of 1, 3, 5, 10 and 20 kGy were 84.98%, 83.70%, 83.94%, 82.84% and 82.58%, respectively. Oxygenated terpenes such as β-eudesmol, α-eudesmol, and verbenone were increased after irradiation but did not correlate with the irradiation dose. The yields of active substances such as essential oil were increased after irradiation; however, the yields of essential oils and the irradiation dose were not correlated. Thus, the profile of composition volatiles of A. gigas Nakai did not change with irradiation.

  14. Laser mode control using leaky plasma channels

    NASA Astrophysics Data System (ADS)

    Djordjević, B. Z.; Benedetti, C.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2017-03-01

    The evolution and propagation of a non-Gaussian laser pulse in matched parabolic channels as well as leaky channels are investigated. It has previously been shown for a Gaussian pulse that matched guiding can be achieved using such channels. In the low power regime, analytical work demonstrates that, for multi-mode pulses, there is significant transverse beating. The interaction between different modes may have an adverse effect on the laser pulse as it propagates through the primary channel, in which plasma wakefield acceleration of the electron beam is to occur, and this effect can be shown in numerical simulations of high-power laser-plasma interactions. To improve guiding of the pulse, we propose using leaky channels. Higher order mode content is minimized through the leaky channel, while the fundamental mode remains well-guided. In addition to numerical simulations, it can be qualitatively shown, through the Wentzel-Kramers-Brillouin (WKB) method and the Source Dependent Expansion (SDE) analysis, that in finite channels, higher order modes either leak out or transfer energy to the fundamental. In conclusion, an idealized plasma filter based on leaky channels is found to filter out the higher order modes and leave a near-Gaussian profile before the pulse enters the primary channel.

  15. On the Hamiltonian structure of large deviations in stochastic hybrid systems

    NASA Astrophysics Data System (ADS)

    Bressloff, Paul C.; Faugeras, Olivier

    2017-03-01

    We present a new derivation of the classical action underlying a large deviation principle (LDP) for a stochastic hybrid system, which couples a piecewise deterministic dynamical system in {{{R}}d} with a time-homogeneous Markov chain on some discrete space Γ . We assume that the Markov chain on Γ is ergodic, and that the discrete dynamics is much faster than the piecewise deterministic dynamics (separation of time-scales). Using the Perron–Frobenius theorem and the calculus-of-variations, we show that the resulting action Hamiltonian is given by the Perron eigenvalue of a | Γ | -dimensional linear equation. The corresponding linear operator depends on the transition rates of the Markov chain and the nonlinear functions of the piecewise deterministic system. We compare the Hamiltonian to one derived using WKB methods, and show that the latter is a reduction of the former. We also indicate how the analysis can be extended to a multi-scale stochastic process, in which the continuous dynamics is described by a piecewise stochastic differential equations (SDE). Finally, we illustrate the theory by considering applications to conductance-based models of membrane voltage fluctuations in the presence of stochastic ion channels.

  16. Effect of γ-irradiation on the volatile compounds of medicinal herb, Paeoniae Radix

    NASA Astrophysics Data System (ADS)

    Shim, Sung-Lye; Hwang, In-Min; Ryu, Keun-Young; Jung, Min-Seok; Seo, Hye-young; Kim, Hee-Yeon; Song, Hyun-Pa; Kim, Jae-Hun; Lee, Ju-Woon; Byun, Myung-Woo; Kwon, Joong-Ho; Kim, Kyong-Su

    2009-07-01

    A study was carried out to find the effect of γ-irradiation on contents of volatile compounds from medicinal herb, Paeoniae Radix ( Paenia albiflora Pallas var. trichocarpa Bunge). The volatile compounds of control, 1, 3, 5 and 10 kGy irradiated samples were extracted by simultaneous steam distillation and extraction (SDE) method and analyzed by gas chromatograph-mass spectrometer. The major volatile compounds were paeonol, ( E)-carveol, ( E, E)-2,4-octadienal, methyl salicylate, myrtanol and eugenol acetate. Volatile compounds belonging to chemical classes of acids, alcohols, aldehydes, esters, hydrocarbons and miscellaneous were identified in all experimental samples. The types of volatile compounds in irradiated samples were similar to those of non-irradiated sample and the concentrations of these compounds differed between treatments. 1,3-Bis (1,1-dimethylethyl)-benzene was identified by using the selected ion monitoring (GC/MS-SIM) mode. The concentration of this compound increased with the increase of irradiation dose level. These results suggest that it could be used as the base data for the effect of γ-irradiation on medicinal herb.

  17. Development of the updated system of city underground pipelines based on Visual Studio

    NASA Astrophysics Data System (ADS)

    Zhang, Jianxiong; Zhu, Yun; Li, Xiangdong

    2009-10-01

    Our city has owned the integrated pipeline network management system with ArcGIS Engine 9.1 as the bottom development platform and with Oracle9i as basic database for storaging data. In this system, ArcGIS SDE9.1 is applied as the spatial data engine, and the system was a synthetic management software developed with Visual Studio visualization procedures development tools. As the pipeline update function of the system has the phenomenon of slower update and even sometimes the data lost, to ensure the underground pipeline data can real-time be updated conveniently and frequently, and the actuality and integrity of the underground pipeline data, we have increased a new update module in the system developed and researched by ourselves. The module has the powerful data update function, and can realize the function of inputting and outputting and rapid update volume of data. The new developed module adopts Visual Studio visualization procedures development tools, and uses access as the basic database to storage data. We can edit the graphics in AutoCAD software, and realize the database update using link between the graphics and the system. Practice shows that the update module has good compatibility with the original system, reliable and high update efficient of the database.

  18. Nonrelativistic quantum mechanics with consideration of influence of fundamental environment

    SciTech Connect

    Gevorkyan, A. S.

    2013-08-15

    Spontaneous transitions between bound states of an atomic system, the 'Lamb Shift' of energy levels and many other phenomena in real nonrelativistic quantum systems are connected with the influence of the quantum vacuum fluctuations (fundamental environment (FE)), which are impossible to consider in the framework of standard quantum-mechanical approaches. The joint system quantum system (QS) and FE is described in the framework of the stochastic differential equation (SDE) of Langevin-Schroedinger type and is defined on the extended space Double-Struck-Capital-R {sup 3} Circled-Times {Xi}{sup n}, where Double-Struck-Capital-R {sup 3} and {Xi}{sup n} are the Euclidean and functional spaces, respectively. The method of stochastic density matrix is developed and the von Neumann equation for reduced density matrix of QS with FE is generalized. The entropy of QS entangled with FE is defined and investigated. It is proved that the interaction of QS with the environment leads to emerging structures of various topologies which present new quantum-field properties of QS. It is shown that when the physical system (irrelatively to its being micro ormacro) breaks up into two fragments by means of FE, there arises between these fragments a nonpotential interaction which does not disappear at large distances.

  19. Structural basis of substrate recognition by a bacterial deubiquitinase important for dynamics of phagosome ubiquitination

    PubMed Central

    Sheedlo, Michael J.; Qiu, Jiazhang; Tan, Yunhao; Paul, Lake N.; Luo, Zhao-Qing; Das, Chittaranjan

    2015-01-01

    Manipulation of the host’s ubiquitin network is emerging as an important strategy for counteracting and repurposing the posttranslational modification machineries of the host by pathogens. Ubiquitin E3 ligases encoded by infectious agents are well known, as are a variety of viral deubiquitinases (DUBs). Bacterial DUBs have been discovered, but little is known about the structure and mechanism underlying their ubiquitin recognition. In this report, we found that members of the Legionella pneumophila SidE effector family harbor a DUB module important for ubiquitin dynamics on the bacterial phagosome. Structural analysis of this domain alone and in complex with ubiquitin vinyl methyl ester (Ub-VME) reveals unique molecular contacts used in ubiquitin recognition. Instead of relying on the Ile44 patch of ubiquitin, as commonly used in eukaryotic counterparts, the SdeADub module engages Gln40 of ubiquitin. The architecture of the active-site cleft presents an open arrangement with conformational plasticity, permitting deubiquitination of three of the most abundant polyubiquitin chains, with a distinct preference for Lys63 linkages. We have shown that this preference enables efficient removal of Lys63 linkages from the phagosomal surface. Remarkably, the structure reveals by far the most parsimonious use of molecular contacts to achieve deubiquitination, with less than 1,000 Å2 of accessible surface area buried upon complex formation with ubiquitin. This type of molecular recognition appears to enable dual specificity toward ubiquitin and the ubiquitin-like modifier NEDD8. PMID:26598703

  20. Cytoplasmic and nuclear quality control and turnover of single-stranded RNA modulate post-transcriptional gene silencing in plants.

    PubMed

    Moreno, Ana Beatriz; Martínez de Alba, Angel Emilio; Bardou, Florian; Crespi, Martin D; Vaucheret, Hervé; Maizel, Alexis; Mallory, Allison C

    2013-04-01

    Eukaryotic RNA quality control (RQC) uses both endonucleolytic and exonucleolytic degradation to eliminate dysfunctional RNAs. In addition, endogenous and exogenous RNAs are degraded through post-transcriptional gene silencing (PTGS), which is triggered by the production of double-stranded (ds)RNAs and proceeds through short-interfering (si)RNA-directed ARGONAUTE-mediated endonucleolytic cleavage. Compromising cytoplasmic or nuclear 5'-3' exoribonuclease function enhances sense-transgene (S)-PTGS in Arabidopsis, suggesting that these pathways compete for similar RNA substrates. Here, we show that impairing nonsense-mediated decay, deadenylation or exosome activity enhanced S-PTGS, which requires host RNA-dependent RNA polymerase 6 (RDR6/SGS2/SDE1) and SUPPRESSOR OF GENE SILENCING 3 (SGS3) for the transformation of single-stranded RNA into dsRNA to trigger PTGS. However, these RQC mutations had no effect on inverted-repeat-PTGS, which directly produces hairpin dsRNA through transcription. Moreover, we show that these RQC factors are nuclear and cytoplasmic and are found in two RNA degradation foci in the cytoplasm: siRNA-bodies and processing-bodies. We propose a model of single-stranded RNA tug-of-war between RQC and S-PTGS that ensures the correct partitioning of RNA substrates among these RNA degradation pathways.

  1. Exactly constructing model of quantum mechanics with random environment

    SciTech Connect

    Gevorkyan, A. S.

    2010-02-15

    Dissipation and decoherence, interaction with the random media, continuous measurements and many other complicated problems of open quantum systems are a result of interaction of quantum system with the random environment. These problems mathematically are described in terms of complex probabilistic processes (CPP). Note that CPP satisfies the stochastic differential equation (SDE) of Langevin-Schroedinger(L-Sch)type, and is defined on the extended space R{sup 1} - R{sub {l_brace}{gamma}{r_brace}}, where R{sup 1} and R{sub {l_brace}{gamma}{r_brace}} are the Euclidean and the functional spaces, correspondingly. For simplicity, the model of 1D quantum harmonic oscillator (QHO) with the stochastic environment is considered. On the basis of orthogonal CPP, the method of stochastic density matrix (SDM) is developed. By S DM method, the thermodynamical potentials, such as the nonequilibrium entropy and the energy of the 'ground state' are constructed in a closed form. The expressions for uncertain relations and Wigner function depending on interaction's constant between 1D QHO and the environment are obtained.

  2. Application of WebGIS in CATV basic network

    NASA Astrophysics Data System (ADS)

    Li, Zhao; Liu, Nan; Liu, Renyi; Bao, Weizheng

    2006-10-01

    This paper analyzes the necessity of the application of WebGIS in CATV basic network. There was almost no research in using WebGIS to manage CATV basic network data in China. This paper briefly introduces how to construct an integrated transaction management system of CATV basic network based on WebGIS, and it forms a database of pivotal points, lines and buildings. CATV basic network based on WebGIS has very great superiority to traditional GIS, anybody can visit the system in anyplace by wired or wireless connection. Therefore it can satisfy the managers who want to query information about network, equipment and customers or response on. In this way the routine network and equipment maintenance becomes easily and fleetly. But WebGIS also has bottle-necks such as vector graphic editing. The editing of vector graphic and attribute play important roles in GIS, especially in CATV basic network management, because equipment, cable and fiber-optic change frequently. This paper develops Zhejiang Jiangshan broadcasting and TV station geographic information system on the basis of ArcIMS platform, and making use of the capability of reading and writing spatial data of ArcSDE to solve vector graphic editing problem.

  3. Integration of Advanced Source and Drain Extension Process Using Carbon/Fluorine Co-Implants and Spike Anneal in 65nm PMOS Devices

    NASA Astrophysics Data System (ADS)

    Li, C. I.; Wang, H. Y.; Chien, C. C.; Chain, M.; Yang, C. L.; Tzou, S. F.; Graoui, H.; Foad, M. A.; Ting, Richard

    2006-11-01

    Carbon and fluorine co-implantation have shown encouraging junction formation improvement, especially for P-type junctions. In this paper, Xj of 20 nm, Rs of 730 ohms/sq and abruptness of 3.5 nm/decade were obtained using carbon co-implantation at 6 keV, 2×1015 ions/cm2, BF2 implant and spike annealing. With LSA, the sheet resistance decreases to 640 ohm/sq. Rs decreased 7% at 1050°C RTP and decreased 13% at 1000°C RTP combined with laser spike annealing. We implemented germanium, carbon, and fluorine co-implanted junctions for SDE fabrication for 65 nm node devices. Results indicated that both decrease in overlap capacitance and junction leakage have proportional correlation with C co-implant dosage. However, Vt needs to be optimized. Device optimization by combining C co-implantation with LSA can yield better control of short channel effects due to the co-implantation and better activation due to the LSA.

  4. Spatial analysis of falls in an urban community of Hong Kong

    PubMed Central

    Lai, Poh C; Low, Chien T; Wong, Martin; Wong, Wing C; Chan, Ming H

    2009-01-01

    Background Falls are an issue of great public health concern. This study focuses on outdoor falls within an urban community in Hong Kong. Urban environmental hazards are often place-specific and dependent upon the built features, landscape characteristics, and habitual activities. Therefore, falls must be examined with respect to local situations. Results This paper uses spatial analysis methods to map fall occurrences and examine possible environmental attributes of falls in an urban community of Hong Kong. The Nearest neighbour hierarchical (Nnh) and Standard Deviational Ellipse (SDE) techniques can offer additional insights about the circumstances and environmental factors that contribute to falls. The results affirm the multi-factorial nature of falls at specific locations and for selected groups of the population. Conclusion The techniques to detect hot spots of falls yield meaningful results that enable the identification of high risk locations. The combined use of descriptive and spatial analyses can be beneficial to policy makers because different preventive measures can be devised based on the types of environmental risk factors identified. The analyses are also important preludes to establishing research hypotheses for more focused studies. PMID:19291326

  5. Chemical composition, antimicrobial property and microencapsulation of Mustard (Sinapis alba) seed essential oil by complex coacervation.

    PubMed

    Peng, Chao; Zhao, Su-Qing; Zhang, Jun; Huang, Gui-Ying; Chen, Lan-Ying; Zhao, Feng-Yi

    2014-12-15

    In this study, the essential oil from mustard seed was isolated by simultaneous steam distillation and extraction (SDE) and analyzed by gas chromatography-mass spectrometry (GC-MS). Fourteen components were identified in the mustard seed essential oil with allyl isothiocyanate being the main component (71.06%). The essential oil has a broad-spectrum antimicrobial activity with inhibition zones and MIC values in the range of 9.68-15.57 mm and 128-512 μg/mL respectively. The essential oil was subsequently encapsulated in complex coacervation microcapsules with genipin, a natural water-soluble cross-linker. The optimum parameters for the hardening effectiveness of the genipin-hardened essential oil microcapsules were 8h at 40°C and pH 10.0 with a genipin concentration of 0.075 g/g gelatin. The genipin-hardened microcapsules had a particle size of mainly 5-10 μm and strong chemistry stability which is potential for its application in food preservation.

  6. Influence of drying on the flavor quality of spearmint (Mentha spicata L.).

    PubMed

    Díaz-Maroto, M Consuelo; Pérez-Coello, M Soledad; González Viñas, M A; Cabezudo, M Dolores

    2003-02-26

    Spearmint (Mentha spicata L.) was dried using three different drying methods: oven-drying at 45 degrees C, air-drying at ambient temperature, and freeze-drying. The effect of the drying method on the volatile compounds and on the structural integrity and sensory characteristics of the spice was evaluated. The volatile components from fresh and dried spearmint samples were isolated by simultaneous distillation-extraction (SDE) and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 28 compounds were identified, carvone, limonene, and 1,8-cineole, in that order, being the main components in all of the samples. Oven-drying at 45 degrees C and air-drying at ambient temperature were the methods that produced the best results. An increase in monoterpenes was observed in all of the dried samples, except in the freeze-dried samples that underwent freezing at -198 degrees C. Freeze-drying resulted in substantial losses in oxygenated terpenes and sesquiterpenes. The effect of each drying method on leaf structure was observed by scanning electron microscopy. From a sensory standpoint, drying the spearmint brought about a decrease in herbaceous and floral notes together with an increase in minty odor.

  7. Numerical simulation of nonlinear dynamical systems driven by commutative noise

    SciTech Connect

    Carbonell, F. Biscay, R.J.; Jimenez, J.C.; Cruz, H. de la

    2007-10-01

    The local linearization (LL) approach has become an effective technique for the numerical integration of ordinary, random and stochastic differential equations. One of the reasons for this success is that the LL method achieves a convenient trade-off between numerical stability and computational cost. Besides, the LL method reproduces well the dynamics of nonlinear equations for which other classical methods fail. However, in the stochastic case, most of the reported works has been focused in Stochastic Differential Equations (SDE) driven by additive noise. This limits the applicability of the LL method since there is a number of interesting dynamics observed in equations with multiplicative noise. On the other hand, recent results show that commutative noise SDEs can be transformed into a random differential equation (RDE) by means of a random diffeomorfism (conjugacy). This paper takes advantages of such conjugacy property and the LL approach for defining a LL scheme for SDEs driven by commutative noise. The performance of the proposed method is illustrated by means of numerical simulations.

  8. Interrelationships Between Aerosol Characteristics and Light Scattering During Late-winter in a Eastern Mediterranean Arid Environment

    NASA Technical Reports Server (NTRS)

    Ichoku, C.; Andreae, M. O.; Meixner, F. X.; Schebeske, G.; Formenti, P.; Maenhaut, W.; Cafmeyer, J.; Ptasinski, J.; Karnieli, A.; Orlovsky, L.

    1999-01-01

    An intensive field campaign involving measurement of various aerosol physical, chemical, and radiative properties was conducted at Sde Boker in the Negev Desert of Israel, from 18 February to 15 March 1997. Nephelometer measurements gave average background scattering coefficient values of about 25 M/m at 550 nm wavelength, but strong dust events caused the value of this parameter to rise up to about 800 M/m Backscattering fractions did not depend on aerosol loading, and generally fell in the range of 0.1 to 0.25, comparable to values reported for marine and Arctic environments. Chemical analysis of the aerosol revealed that, in the coarse size range (2 - 10 micrometer equivalent aerodynamic diameter (EAD)), calcium (Ca) was by far the most abundant element followed by silicon (Si), both of which are indicators for mineral dust. In the fine size fraction (< 2 micrometers EAD), sulfur (S) generally was the dominant element, except during high dust episodes when Ca and Si were again the most abundant. Furthermore, fine black carbon (BC) correlates with S, suggesting that they may have originated from the same sources or source regions. An indication of the short-term effect of aerosol loading on radiative forcing was provided by measurements of global and diffuse solar radiation, which showed that during high turbidity periods (strong dust events) almost all of the solar radiation reaching the area is scattered or absorbed.

  9. Solving Parker's transport equation with stochastic differential equations on GPUs

    NASA Astrophysics Data System (ADS)

    Dunzlaff, P.; Strauss, R. D.; Potgieter, M. S.

    2015-07-01

    The numerical solution of transport equations for energetic charged particles in space is generally very costly in terms of time. Besides the use of multi-core CPUs and computer clusters in order to decrease the computation times, high performance calculations on graphics processing units (GPUs) have become available during the last years. In this work we introduce and describe a GPU-accelerated implementation of Parker's equation using Stochastic Differential Equations (SDEs) for the simulation of the transport of energetic charged particles with the CUDA toolkit, which is the focus of this work. We briefly discuss the set of SDEs arising from Parker's transport equation and their application to boundary value problems such as that of the Jovian magnetosphere. We compare the runtimes of the GPU code with a CPU version of the same algorithm. Compared to the CPU implementation (using OpenMP and eight threads) we find a performance increase of about a factor of 10-60, depending on the assumed set of parameters. Furthermore, we benchmark our simulation using the results of an existing SDE implementation of Parker's transport equation.

  10. Rapid discrimination of the geographical origins of an oolong tea (anxi-tieguanyin) by near-infrared spectroscopy and partial least squares discriminant analysis.

    PubMed

    Yan, Si-Min; Liu, Jun-Ping; Xu, Lu; Fu, Xian-Shu; Cui, Hai-Feng; Yun, Zhen-Yu; Yu, Xiao-Ping; Ye, Zi-Hong

    2014-01-01

    This paper focuses on a rapid and nondestructive way to discriminate the geographical origin of Anxi-Tieguanyin tea by near-infrared (NIR) spectroscopy and chemometrics. 450 representative samples were collected from Anxi County, the original producing area of Tieguanyin tea, and another 120 Tieguanyin samples with similar appearance were collected from unprotected producing areas in China. All these samples were measured by NIR. The Stahel-Donoho estimates (SDE) outlyingness diagnosis was used to remove the outliers. Partial least squares discriminant analysis (PLSDA) was performed to develop a classification model and predict the authenticity of unknown objects. To improve the sensitivity and specificity of classification, the raw data was preprocessed to reduce unwanted spectral variations by standard normal variate (SNV) transformation, taking second-order derivatives (D2) spectra, and smoothing. As the best model, the sensitivity and specificity reached 0.931 and 1.000 with SNV spectra. Combination of NIR spectrometry and statistical model selection can provide an effective and rapid method to discriminate the geographical producing area of Anxi-Tieguanyin.

  11. Reconstructing source polybrominated diphenyl ether congener patterns from semipermeable membrane devices in the Fraser River, British Columbia, Canada: comparison to commercial mixtures.

    PubMed

    Rayne, Sierra; Ikonomou, Michael G

    2002-11-01

    Semipermeable membrane devices (SPMDs) were placed in the Fraser River near Vancouver, British Columbia, Canada, between August 6 and September 30, 1996. This location is near a large urban and industrial region (population 2,000,000) and is expected to be representative of other large, modern cities. After exposure to the ambient water column, SPMD samples were analyzed for a suite of 36 polybrominated diphenyl ether (PBDE) congeners plus all homologue groups from mono- through hexa-brominated. Observed congener patterns differed significantly from that of the commercial penta- and octa-BDE mixtures. A reconstruction approach was developed based on an aquatic transport model and utilizing published octanol-water partition coefficients, calculated SPMD uptake rates, and predicted water concentrations by using the EcoFate multimedia mass balance aquatic simulation model for the 13 major PBDE congeners. In combination, composite technical mixtures were created by combining commercial penta-BDE mixtures (Bromkal 70-SDE and Great Lakes Chemicals DE-71) with commercial octa-BDE mixtures (Bromkal 79-8DE and Great Lakes Chemicals DE-79) in their relative 2000 North American production volumes. The reconstructed SPMD patterns more closely approximated the composite technical mixtures and suggest that PBDEs in such an industrial region arise primarily from penta- and octa-BDE source mixtures.

  12. SAMS Acceleration Measurements on MIR

    NASA Technical Reports Server (NTRS)

    Moskowitz, Milton E.; Hrovat, Kenneth; Finkelstein, Robert; Reckart, Timothy

    1997-01-01

    During NASA Increment 3 (September 1996 to January 1997), about 5 gigabytes of acceleration data were collected by the Space Acceleration Measurement System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 11 optical disks and were returned to Earth on STS-81. During this time, SAMS data were collected in the Priroda module to support the following experiments: the Mir Structural Dynamics Experiment (MiSDE) and Binary Colloidal Alloy Tests (BCAT). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-81 operations, a Progress engine burn, attitude control thruster operation, and crew exercise. Also included are a description of the Mir module orientations, and the panel notations within the modules. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. Variations in the acceleration environment caused by unique activities such as crew exercise and life-support fans are presented. The analyses included herein complement those presented in previous mission summary reports published by the Principal Investigator Microgravity Services (PIMS) group.

  13. Finite element formulation of fluctuating hydrodynamics for fluids filled with rigid particles using boundary fitted meshes

    SciTech Connect

    De Corato, M.; Slot, J.J.M.; Hütter, M.; D'Avino, G.; Maffettone, P.L.; Hulsen, M.A.

    2016-07-01

    In this paper, we present a finite element implementation of fluctuating hydrodynamics with a moving boundary fitted mesh for treating the suspended particles. The thermal fluctuations are incorporated into the continuum equations using the Landau and Lifshitz approach [1]. The proposed implementation fulfills the fluctuation–dissipation theorem exactly at the discrete level. Since we restrict the equations to the creeping flow case, this takes the form of a relation between the diffusion coefficient matrix and friction matrix both at the particle and nodal level of the finite elements. Brownian motion of arbitrarily shaped particles in complex confinements can be considered within the present formulation. A multi-step time integration scheme is developed to correctly capture the drift term required in the stochastic differential equation (SDE) describing the evolution of the positions of the particles. The proposed approach is validated by simulating the Brownian motion of a sphere between two parallel plates and the motion of a spherical particle in a cylindrical cavity. The time integration algorithm and the fluctuating hydrodynamics implementation are then applied to study the diffusion and the equilibrium probability distribution of a confined circle under an external harmonic potential.

  14. Heavy metal levels of pasture grasses in metropolitan area

    NASA Astrophysics Data System (ADS)

    Luilo, G. B.; Othman, O. C.

    2003-05-01

    Urban agriculture is becoming an important lucrative activity in Dar es Salaam City even though the city is subject to traffic and industrial pollution pressures. Poor planning has left only limited spaces, particularly road reserves, for cultivation and foraging animals. While there is increasing road traffic no study bas been conducted determine levels of trace metals in pasture grasses. This study, therefore, reports on the levels of cadmium, manganese, lead and zinc of cynodon grasses in road vicinity in the city. Results show that the trace metal levels (ppm ± SDE) in Cynodon grass species were: Cd (0.24 ± 0.06-2.58 ± 0.15), Mn (41.5 ± 13.6-345.0 ± 124.3), Pb (1.15 ± 0.64-25.53 ± 1.29) and Zn (25.97 ± 3.69-95.36 ± 19.61). The mean levels of lead and zinc varied exponentially with distance off the road up to 15 m distance. Lead and zinc levels correlated with average daily traffic in the roads while cadmium and manganese did not. This suggests that lead and zinc in grasses owe their sources from the passing motor vehicles in agreement with other reported studies. It is recommended that pasture grasses in road vicinities must not be used for foraging dairy cattle and goats for public health reasons.

  15. Fatty acid composition and volatile compounds of caviar from farmed white sturgeon (Acipenser transmontanus).

    PubMed

    Caprino, Fabio; Moretti, Vittorio Maria; Bellagamba, Federica; Turchini, Giovanni Mario; Busetto, Maria Letizia; Giani, Ivan; Paleari, Maria Antonietta; Pazzaglia, Mario

    2008-06-09

    The present study was conducted to characterize caviar obtained from farmed white sturgeons (Acipenser transmontanus) subjected to different dietary treatments. Twenty caviar samples from fish fed two experimental diets containing different dietary lipid sources have been analysed for chemical composition, fatty acids and flavour volatile compounds. Fatty acid make up of caviar was only minimally influenced by dietary fatty acid composition. Irrespective of dietary treatments, palmitic acid (16:0) and oleic acid (OA, 18:1 n-9) were the most abundant fatty acid followed by docosahexaenoic acid (DHA, 22:6 n-3) and eicopentaenoic (EPA, 20:5 n-3). Thirty-three volatile compounds were isolated using simultaneous distillation-extraction (SDE) and identified by GC-MS. The largest group of volatiles were represented by aldehydes with 20 compounds, representing the 60% of the total volatiles. n-Alkanals, 2-alkenals and 2,4-alkadienals are largely the main responsible for a wide range of flavours in caviar from farmed white surgeon.

  16. SAMS Acceleration Measurements on Mir From January to May 1997 (NASA Increment 4)

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1998-01-01

    During NASA Increment 4 (January to May 1997), about 5 gigabytes of acceleration data were collected by the Space Acceleration Measurements System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 28 optical disks which were returned to Earth on STS-84. During this increment, SAMS data were collected in the Priroda module to support the Mir Structural Dynamics Experiment (MiSDE), the Binary Colloidal Alloy Tests (BCAT), Angular Liquid Bridge (ALB), Candle Flames in Microgravity (CFM), Diffusion Controlled Apparatus Module (DCAM), Enhanced Dynamic Load Sensors (EDLS), Forced Flow Flame Spreading Test (FFFT), Liquid Metal Diffusion (LMD), Protein Crystal Growth in Dewar (PCG/Dewar), Queen's University Experiments in Liquid Diffusion (QUELD), and Technical Evaluation of MIM (TEM). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-84 operations, a Progress engine burn, Soyuz vehicle docking and undocking, and Progress vehicle docking. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. The analyses included herein complement those presented in previous summary reports prepared by the Principal Investigator Microgravity Services (PIMS) group.

  17. SAMS Acceleration Measurements on Mir (NASA Increment 4)

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1998-01-01

    During NASA Increment 4 (January to May 1997), about 5 gigabytes of acceleration data were collected by the Space Acceleration Measurements System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 28 optical disks which were returned to Earth on STS-84. During this increment, SAMS data were collected in the Priroda module to support the Mir Structural Dynamics Experiment (MiSDE), the Binary Colloidal Alloy Tests (BCAT), Angular Liquid Bridge (ALB), Candle Flames in Microgravity (CFM), Diffusion Controlled Apparatus Module (DCAM), Enhanced Dynamic Load Sensors (EDLS), Forced Flow Flame Spreading Test (FFFr), Liquid Metal Diffusion (LMD), Protein Crystal Growth in Dewar (PCG/Dewar), Queen's University Experiments in Liquid Diffusion (QUELD), and Technical Evaluation of MIM (TEM). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-84 operations, a Progress engine bum, Soyuz vehicle docking and undocking, and Progress vehicle docking. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. The analyses included herein complement those presented in previous summary reports prepared by the Principal Investigator Microgravity Services (PIMS) group.

  18. About the infinite dimensional skew and obliquely reflected Ornstein-Uhlenbeck process

    NASA Astrophysics Data System (ADS)

    Röckner, Michael; Trutnau, Gerald

    2015-12-01

    Based on an integration by parts formula for closed and convex subsets Γ of a separable real Hilbert space H with respect to a Gaussian measure, we first construct and identify the infinite dimensional analogue of the obliquely reflected Ornstein-Uhlenbeck process (perturbed by a bounded drift B) by means of a Skorokhod type decomposition. The variable oblique reflection at a reflection point of the boundary ∂Γ is uniquely described through a reflection angle and a direction in the tangent space (more precisely through an element of the orthogonal complement of the normal vector) at the reflection point. In case of normal reflection at the boundary of a regular convex set and under some monotonicity condition on B, we prove the existence and uniqueness of a strong solution to the corresponding SDE. Subsequently, we consider an increasing sequence (Γαk)k∈ℤ of closed and convex subsets of H and the skew reflection problem at the boundaries of this sequence. We present concrete examples and obtain as a special case the infinite dimensional analogue of the p-skew reflected Ornstein-Uhlenbeck process.

  19. Substrate removal and electricity generation in a membrane-less microbial fuel cell for biological treatment of wastewater.

    PubMed

    Wang, Haiping; Jiang, Sunny C; Wang, Yun; Xiao, Bo

    2013-06-01

    Microbial fuel cells have gained popularity in recent years due to its promise in converting organic wastewater into renewable electrical energy. In this study, a membrane-less MFC with a biocathode was developed to evaluate its performance in electricity generation while simultaneously treating wastewater. The MFC fed with a continuous flow of 2g/day acetate produced a power density of 30 mW/m(2) and current density of 245 mA/m(2). A substrate degradation efficiency (SDE) of 75.9% was achieved with 48.7% attributed to the anaerobic process and 27.2% to the aerobic process. Sequencing analysis of the microbial consortia using 16S rDNA pryosequencing showed the predominance of Bacteroidia in the anode after one month of operation, while the microbial community in the cathode chamber was dominated by Gamma-proteobacteria and Beta-proteobacteria. Coulombic efficiencies varied from 19.8% to 58.1% using different acetate concentrations, indicating power density can be further improved through the accumulation of electron-transferring bacteria.

  20. Nonrelativistic quantum mechanics with consideration of influence of fundamental environment

    NASA Astrophysics Data System (ADS)

    Gevorkyan, A. S.

    2013-08-01

    Spontaneous transitions between bound states of an atomic system, the "Lamb Shift" of energy levels and many other phenomena in real nonrelativistic quantum systems are connected with the influence of the quantum vacuum fluctuations ( fundamental environment (FE)), which are impossible to consider in the framework of standard quantum-mechanical approaches. The joint system quantum system (QS) and FE is described in the framework of the stochastic differential equation (SDE) of Langevin-Schrödinger type and is defined on the extended space ℝ3⊗Ξ n , where ℝ3 and Ξ n are the Euclidean and functional spaces, respectively. The method of stochastic density matrix is developed and the von Neumann equation for reduced density matrix of QS with FE is generalized. The entropy of QS entangled with FE is defined and investigated. It is proved that the interaction of QS with the environment leads to emerging structures of various topologies which present new quantum-field properties of QS. It is shown that when the physical system (irrelatively to its being micro ormacro) breaks up into two fragments by means of FE, there arises between these fragments a nonpotential interaction which does not disappear at large distances.

  1. Stable, high-performance operation of a fiber-coupled superconducting nanowire avalanche photon detector.

    PubMed

    Miki, Shigehito; Yabuno, Masahiro; Yamashita, Taro; Terai, Hirotaka

    2017-03-20

    Recent progress in the development of superconducting nanowire single photon detectors (SSPD or SNSPD) has delivered excellent performance, and has had a great impact on a range of research fields. Significant efforts are being made to further improve the technology, and a primary concern remains to resolve the trade-offs between detection efficiency (DE), timing jitter, and response speed. We present a stable and high-performance fiber-coupled niobium titanium nitride superconducting nanowire avalanche photon detector (SNAP) that resolves these trade-offs. Autocorrelation function measurement revealed an afterpulse-free operation in serially connected two SNAP (SC-2SNAP), even in the absence of a choke inductor, achieving a 7.65 times faster response speed than standard SSPDs. The SC-2SNAP device showed a system detection efficiency (SDE) of 81.0% with wide bias current margin, a dark count rate of 6.8 counts/s, and full width at half maximum timing jitter of 68 ps, operating in a practical Gifford-McMahon cryocooler system.

  2. A generalizability analysis of score consistency for the Balanced Inventory of Desirable Responding.

    PubMed

    Vispoel, Walter P; Tao, Shuqin

    2013-03-01

    Our goal in this investigation was to evaluate the reliability of scores from the Balanced Inventory of Desirable Responding (BIDR) more comprehensively than in prior research using a generalizability-theory framework based on both dichotomous and polytomous scoring of items. Generalizability coefficients accounting for specific-factor, transient, and random-response error ranged from .64 to .75 for the BIDR's Self-Deception Enhancement (SDE) and Impression Management (IM) subscale scores, and these values were systematically lower than corresponding alpha (.66 to .83) and 1-week test-retest (.78 to .86) coefficients. Polytomous scoring provided higher reliability than dichotomous scoring on nearly all indexes reported. Random-response (8%-17%) and specific factor error (11%-17%) exceeded transient error (3%-6%) for both subscales and scoring methods. Doubling the number of items on a single occasion provided greater improvements in generalizability (.76-.83) than aggregating scores across 2 administrations (.72-.81). Both scoring methods provided reasonably high indexes of consistency (φ coefficients≥.91) at cut scores on the IM scale for detecting faked responses when all sources of error were taken into account. Implications of these results for common uses of the BIDR are discussed.

  3. Stochastic Approach for Modeling of DNAPL Migration in Heterogeneous Aquifers: Model Development and Experimental Data Generation

    NASA Astrophysics Data System (ADS)

    Dean, D. W.; Illangasekare, T. H.; Turner, A.; Russell, T. F.

    2004-12-01

    Modeling of the complex behavior of DNAPLs in naturally heterogeneous subsurface formations poses many challenges. Even though considerable progress have been made in developing improved numerical schemes to solve the governing partial differential equations, most of these methods still rely on deterministic description of the processes. This research explores the use of stochastic differential equations to model multiphase flow in heterogeneous aquifers, specifically the flow of DNAPLs in saturated soils. The models developed are evaluated using experimental data generated in two-dimensional test systems. A fundamental assumption used in the model formulation is that the movement of a fluid particle in each phase is described by a stochastic process and that the positions of all fluid particles over time are governed by a specific law. It is this law, which we seek to determine. The approach results in a nonlinear stochastic differential equation describing the position of the non-wetting phase fluid particle. The nonlinearity in the stochastic differential equation arises because both the drift and diffusion coefficients depend on the volumetric fraction of the phase, which in turn depends on the position of the fluid particles in the problem domain. The concept of a fluid particle is central to the development of the proposed model. Expressions for both saturation and volumetric fraction are developed using this concept of fluid particle. Darcy's law and the continuity equation are used to derive a Fokker-Planck equation governing flow. The Ito calculus is then applied to derive a stochastic differential equation(SDE) for the non-wetting phase. This SDE has both drift and diffusion terms which depend on the volumetric fraction of the non-wetting phase. Standard stochastic theories based on the Ito calculus and the Wiener process and the equivalent Fokker-Planck PDE's are typically used to model diffusion processes. However, these models, in their usual form

  4. Degradation of Phthalate and Di-(2-Ethylhexyl)phthalate by Indigenous and Inoculated Microorganisms in Sludge-Amended Soil

    PubMed Central

    Roslev, Peter; Madsen, Peter L.; Thyme, Jesper B.; Henriksen, Kaj

    1998-01-01

    The metabolism of phthalic acid (PA) and di-(2-ethylhexyl)phthalate (DEHP) in sludge-amended agricultural soil was studied with radiotracer techniques. The initial rates of metabolism of PA and DEHP (4.1 nmol/g [dry weight]) were estimated to be 731.8 and 25.6 pmol/g (dry weight) per day, respectively. Indigenous microorganisms assimilated 28 and 17% of the carbon in [14C]PA and [14C]DEHP, respectively, into microbial biomass. The rates of DEHP metabolism were much greater in sludge assays without soil than in assays with sludge-amended soil. Mineralization of [14C]DEHP to 14CO2 increased fourfold after inoculation of sludge and soil samples with DEHP-degrading strain SDE 2. The elevated mineralization potential was maintained for more than 27 days. Experiments performed with strain SDE 2 suggested that the bioavailability and mineralization of DEHP decreased substantially in the presence of soil and sludge components. The microorganisms metabolizing PA and DEHP in sludge and sludge-amended soil were characterized by substrate-specific radiolabelling, followed by analysis of 14C-labelled phospholipid ester-linked fatty acids (14C-PLFAs). This assay provided a radioactive fingerprint of the organisms actively metabolizing [14C]PA and [14C]DEHP. The 14C-PLFA fingerprints showed that organisms with different PLFA compositions metabolized PA and DEHP in sludge-amended soil. In contrast, microorganisms with comparable 14C-PLFA fingerprints were found to dominate DEHP metabolism in sludge and sludge-amended soil. Our results suggested that indigenous sludge microorganisms dominated DEHP degradation in sludge-amended soil. Mineralization of DEHP and PA followed complex kinetics that could not be described by simple first-order equations. The initial mineralization activity was described by an exponential function; this was followed by a second phase that was described best by a fractional power function. In the initial phase, the half times for PA and DEHP in sludge

  5. Implicit particle filtering for equations with partial noise and application to geomagnetic data assimilation

    NASA Astrophysics Data System (ADS)

    Morzfeld, M.; Atkins, E.; Chorin, A. J.

    2011-12-01

    The task in data assimilation is to identify the state of a system from an uncertain model supplemented by a stream of incomplete and noisy data. The model is typically given in form of a discretization of an Ito stochastic differential equation (SDE), x(n+1) = R(x(n))+ G W(n), where x is an m-dimensional vector and n=0,1,2,.... The m-dimensional vector function R and the m x m matrix G depend on the SDE as well as on the discretization scheme, and W is an m-dimensional vector whose elements are independent standard normal variates. The data are y(n) = h(x(n))+QV(n) where h is a k-dimensional vector function, Q is a k x k matrix and V is a vector whose components are independent standard normal variates. One can use statistics of the conditional probability density (pdf) of the state given the observations, p(n+1)=p(x(n+1)|y(1), ... , y(n+1)), to identify the state x(n+1). Particle filters approximate p(n+1) by sequential Monte Carlo and rely on the recursive formulation of the target pdf, p(n+1)∝p(x(n+1)|x(n)) p(y(n+1)|x(n+1)). The pdf p(x(n+1)|x(n)) can be read off of the model equations to be a Gaussian with mean R(x(n)) and covariance matrix Σ = GG^T, where the T denotes a transposed; the pdf p(y(n+1)|x(n+1)) is a Gaussian with mean h(x(n+1)) and covariance QQ^T. In a sampling-importance-resampling (SIR) filter one samples new values for the particles from a prior pdf and then one weighs these samples with weights determined by the observations, to yield an approximation to p(n+1). Such weighting schemes often yield small weights for many of the particles. Implicit particle filtering overcomes this problem by using the observations to generate the particles, thus focusing attention on regions of large probability. A suitable algebraic equation that depends on the model and the observations is constructed for each particle, and its solution yields high probability samples of p(n+1). In the current formulation of the implicit particle filter, the state

  6. Effectiveness of primate seed dispersers for an "oversized" fruit, Garcinia benthamii.

    PubMed

    McConkey, Kim R; Brockelman, Warren Y; Saralamba, Chanpen; Nathalang, Anuttara

    2015-10-01

    The largest fruits found in tropical forests may depend on complementary seed dispersal strategies. These fruits are dispersed most effectively by megafauna, but populations can persist where megafauna are absent or erratic visitors. Smaller animals often consume these large fruits, but their capacity to disperse these seeds effectively has rarely been assessed. We evaluated the contributions of gibbons (Hylobates lar) and other frugivores in the seed dispersal of the megafaunal fruit Garcinia benthamii, using the SDE (seed dispersal effectiveness) landscape. Gibbons preferentially consumed G. benthamii fruits and were the main seed disperser that we observed. However, gibbons became satiated when availability was high, with 57% of fruits falling to the ground unhandled. Recruitment of seedlings from gibbon-dispersed seeds was also very low. Elephants consumed G. benthamii fruit, but occurred at low density and were rare visitors to the trees. We suggest that gibbons might complement the seed dispersal role of elephants for G. benthamii, allowing limited recruitment in areas (such as the study site) where elephants occur at low density. Fruit availability varied between years; when availability was low, gibbons reliably consumed most of the crop and dispersed some seeds that established seedlings, albeit at low numbers (2.5 seedlings per crop). When fruit availability was high, the fruit supply overwhelmed the gibbons and other arboreal frugivores, ensuring a large abundance of fruit available to terrestrial seed dispersers. Although gibbons effectively dispersed more seeds at these times (20.7 seedlings per crop), there was the potential for elephants to move many more seeds. Complementary seed dispersal strategies may be important for megafaunal fruit, because they ensure that very large fruits are able to benefit from megafaunal dispersal but also persist where this dispersal becomes erratic. However, our data suggest that smaller seed dispersers might not be

  7. Preliminary prediction of inflow into the D-holes at the Stripa Mine

    SciTech Connect

    Long, J.C.S.; Karasaki, K.; Davey, A.; Peterson, J.; Landsfeld, M.; Kemeny, J.; Martel, S.

    1990-02-01

    Lawrence Berkeley Laboratory (LBL) is contracted by the US Department of Energy to provide an auxiliary modeling effort for the Stripa Project. Within this effort, we are making calculations of inflow to the Simulated Drift Experiment (SDE), i.e. inflow to six parallel, closely spaced D-holes, using a preliminary set of data collected in five other holes, the N- and W-holes during Stages 1 and 2 of the Site Characterization and Validation (SCV) project. Our approach has been to focus on the fracture zones rather than the general set of ubiquitous fractures. Approximately 90% of all the water flowing in the rock is flowing in fracture zones which are neither uniformly conductive nor are they infinitely extensive. Our approach has been to adopt the fracture zone locations as they have been identified with geophysics. We use geologic sense and the original geophysical data to add one zone where significant water inflow has been observed that can not be explained with the other geophysical zones. This report covers LBL's preliminary prediction of flow into the D-holes. Care should be taken in interpreting the results given in this report. As explained below, the approach that LBL has designed for developing a fracture hydrology model requires cross-hole hydrologic data. Cross-hole tests are planned for Stage 3 but were unavailable in Stage 1. As such, we have inferred from available data what a cross-hole test might show and used this synthetic data to make a preliminary calculation of the inflow into the D-holes. Then using all the Stage 3 data we will calculate flow into the Validation Drift itself. The report mainly demonstrates the use of our methodology and the simulated results should be considered preliminary.

  8. Quantifying Transient 3D Dynamical Phenomena of Single mRNA Particles in Live Yeast Cell Measurements

    PubMed Central

    Calderon, Christopher P.; Thompson, Michael A.; Casolari, Jason M.; Paffenroth, Randy C.; Moerner, W. E.

    2013-01-01

    Single-particle tracking (SPT) has been extensively used to obtain information about diffusion and directed motion in a wide range of biological applications. Recently, new methods have appeared for obtaining precise (10s of nm) spatial information in three dimensions (3D) with high temporal resolution (measurements obtained every 4ms), which promise to more accurately sense the true dynamical behavior in the natural 3D cellular environment. Despite the quantitative 3D tracking information, the range of mathematical methods for extracting information about the underlying system has been limited mostly to mean-squared displacement analysis and other techniques not accounting for complex 3D kinetic interactions. There is a great need for new analysis tools aiming to more fully extract the biological information content from in vivo SPT measurements. High-resolution SPT experimental data has enormous potential to objectively scrutinize various proposed mechanistic schemes arising from theoretical biophysics and cell biology. At the same time, methods for rigorously checking the statistical consistency of both model assumptions and estimated parameters against observed experimental data (i.e. goodness-of-fit tests) have not received great attention. We demonstrate methods enabling (1) estimation of the parameters of 3D stochastic differential equation (SDE) models of the underlying dynamics given only one trajectory; and (2) construction of hypothesis tests checking the consistency of the fitted model with the observed trajectory so that extracted parameters are not over-interpreted (the tools are applicable to linear or nonlinear SDEs calibrated from non-stationary time series data). The approach is demonstrated on high-resolution 3D trajectories of single ARG3 mRNA particles in yeast cells in order to show the power of the methods in detecting signatures of transient directed transport. The methods presented are generally relevant to a wide variety of 2D and 3D SPT

  9. Modeling Bacterial Population Growth from Stochastic Single-Cell Dynamics

    PubMed Central

    Molina, Ignacio; Theodoropoulos, Constantinos

    2014-01-01

    A few bacterial cells may be sufficient to produce a food-borne illness outbreak, provided that they are capable of adapting and proliferating on a food matrix. This is why any quantitative health risk assessment policy must incorporate methods to accurately predict the growth of bacterial populations from a small number of pathogens. In this aim, mathematical models have become a powerful tool. Unfortunately, at low cell concentrations, standard deterministic models fail to predict the fate of the population, essentially because the heterogeneity between individuals becomes relevant. In this work, a stochastic differential equation (SDE) model is proposed to describe variability within single-cell growth and division and to simulate population growth from a given initial number of individuals. We provide evidence of the model ability to explain the observed distributions of times to division, including the lag time produced by the adaptation to the environment, by comparing model predictions with experiments from the literature for Escherichia coli, Listeria innocua, and Salmonella enterica. The model is shown to accurately predict experimental growth population dynamics for both small and large microbial populations. The use of stochastic models for the estimation of parameters to successfully fit experimental data is a particularly challenging problem. For instance, if Monte Carlo methods are employed to model the required distributions of times to division, the parameter estimation problem can become numerically intractable. We overcame this limitation by converting the stochastic description to a partial differential equation (backward Kolmogorov) instead, which relates to the distribution of division times. Contrary to previous stochastic formulations based on random parameters, the present model is capable of explaining the variability observed in populations that result from the growth of a small number of initial cells as well as the lack of it compared to

  10. The GEOSS Clearinghouse based on the GeoNetwork opensource

    NASA Astrophysics Data System (ADS)

    Liu, K.; Yang, C.; Wu, H.; Huang, Q.

    2010-12-01

    The Global Earth Observation System of Systems (GEOSS) is established to support the study of the Earth system in a global community. It provides services for social management, quick response, academic research, and education. The purpose of GEOSS is to achieve comprehensive, coordinated and sustained observations of the Earth system, improve monitoring of the state of the Earth, increase understanding of Earth processes, and enhance prediction of the behavior of the Earth system. In 2009, GEO called for a competition for an official GEOSS clearinghouse to be selected as a source to consolidating catalogs for Earth observations. The Joint Center for Intelligent Spatial Computing at George Mason University worked with USGS to submit a solution based on the open-source platform - GeoNetwork. In the spring of 2010, the solution is selected as the product for GEOSS clearinghouse. The GEOSS Clearinghouse is a common search facility for the Intergovernmental Group on Ea rth Observation (GEO). By providing a list of harvesting functions in Business Logic, GEOSS clearinghouse can collect metadata from distributed catalogs including other GeoNetwork native nodes, webDAV/sitemap/WAF, catalog services for the web (CSW)2.0, GEOSS Component and Service Registry (http://geossregistries.info/), OGC Web Services (WCS, WFS, WMS and WPS), OAI Protocol for Metadata Harvesting 2.0, ArcSDE Server and Local File System. Metadata in GEOSS clearinghouse are managed in a database (MySQL, Postgresql, Oracle, or MckoiDB) and an index of the metadata is maintained through Lucene engine. Thus, EO data, services, and related resources can be discovered and accessed. It supports a variety of geospatial standards including CSW and SRU for search, FGDC and ISO metadata, and WMS related OGC standards for data access and visualization, as linked from the metadata.

  11. Modeling bacterial population growth from stochastic single-cell dynamics.

    PubMed

    Alonso, Antonio A; Molina, Ignacio; Theodoropoulos, Constantinos

    2014-09-01

    A few bacterial cells may be sufficient to produce a food-borne illness outbreak, provided that they are capable of adapting and proliferating on a food matrix. This is why any quantitative health risk assessment policy must incorporate methods to accurately predict the growth of bacterial populations from a small number of pathogens. In this aim, mathematical models have become a powerful tool. Unfortunately, at low cell concentrations, standard deterministic models fail to predict the fate of the population, essentially because the heterogeneity between individuals becomes relevant. In this work, a stochastic differential equation (SDE) model is proposed to describe variability within single-cell growth and division and to simulate population growth from a given initial number of individuals. We provide evidence of the model ability to explain the observed distributions of times to division, including the lag time produced by the adaptation to the environment, by comparing model predictions with experiments from the literature for Escherichia coli, Listeria innocua, and Salmonella enterica. The model is shown to accurately predict experimental growth population dynamics for both small and large microbial populations. The use of stochastic models for the estimation of parameters to successfully fit experimental data is a particularly challenging problem. For instance, if Monte Carlo methods are employed to model the required distributions of times to division, the parameter estimation problem can become numerically intractable. We overcame this limitation by converting the stochastic description to a partial differential equation (backward Kolmogorov) instead, which relates to the distribution of division times. Contrary to previous stochastic formulations based on random parameters, the present model is capable of explaining the variability observed in populations that result from the growth of a small number of initial cells as well as the lack of it compared to

  12. The Relative Contributions of Low-Frequency Atmospheric Circulation, Chaotic Dynamics and Land-Atmosphere Feedbacks to the Variability of the Regional-Scale Water Balance

    NASA Astrophysics Data System (ADS)

    Kochendorfer, J. P.; Ramirez, J. A.

    2006-05-01

    In previous work, we developed a conceptually simple statistical-dynamical model of the regional-scale, coupled land-atmosphere water balance, which is formulated as a single stochastic differential equation (SDE) with soil moisture as its state variable. Under differing assumptions about the nature and strength of feedbacks to precipitation, we derived several approximate analytical solutions to the governing Fokker-Planck equation in the form of probability density functions of region-average soil moisture. Using NCEP/NCAR re-analysis data, estimates of potential evapotranspiration, and long-term observations of precipitation, streamflow, and soil moisture, parameter values were estimated for a 5-deg by 5-deg region encompassing the state of Illinois. It was then shown that precipitation-efficiency feedbacks can be significant contributors to the temporal variability of soil moisture, while precipitation recycling increases that variability by a negligible amount at the scale of the study region. In this paper, we first briefly review that earlier work. We next extend the analysis to several other domains within the central United States, thereby drawing conclusions about the strength of precipitation-efficiency feedbacks as a function of climate. We then use the modeling framework to examine the sources of persistence and interannual variability in both soil moisture and precipitation. It is shown that the autocorrelation function of daily precipitation contains a dominant short-memory component, as well as a low-grade, long-memory component. It is suggested that the former is due to chaotic atmospheric dynamics, while the latter is due to a combination of land-atmosphere feedbacks and low-frequency variability in advected atmospheric moisture flux. Finally, it is demonstrated the model is capable of distinguishing between all three sources of variability.

  13. Multiscale modeling of mucosal immune responses

    PubMed Central

    2015-01-01

    Computational modeling techniques are playing increasingly important roles in advancing a systems-level mechanistic understanding of biological processes. Computer simulations guide and underpin experimental and clinical efforts. This study presents ENteric Immune Simulator (ENISI), a multiscale modeling tool for modeling the mucosal immune responses. ENISI's modeling environment can simulate in silico experiments from molecular signaling pathways to tissue level events such as tissue lesion formation. ENISI's architecture integrates multiple modeling technologies including ABM (agent-based modeling), ODE (ordinary differential equations), SDE (stochastic modeling equations), and PDE (partial differential equations). This paper focuses on the implementation and developmental challenges of ENISI. A multiscale model of mucosal immune responses during colonic inflammation, including CD4+ T cell differentiation and tissue level cell-cell interactions was developed to illustrate the capabilities, power and scope of ENISI MSM. Background Computational techniques are becoming increasingly powerful and modeling tools for biological systems are of greater needs. Biological systems are inherently multiscale, from molecules to tissues and from nano-seconds to a lifespan of several years or decades. ENISI MSM integrates multiple modeling technologies to understand immunological processes from signaling pathways within cells to lesion formation at the tissue level. This paper examines and summarizes the technical details of ENISI, from its initial version to its latest cutting-edge implementation. Implementation Object-oriented programming approach is adopted to develop a suite of tools based on ENISI. Multiple modeling technologies are integrated to visualize tissues, cells as well as proteins; furthermore, performance matching between the scales is addressed. Conclusion We used ENISI MSM for developing predictive multiscale models of the mucosal immune system during gut

  14. Comparative Evaluation of Partial α2 -Adrenoceptor Agonist and Pure α2 -Adrenoceptor Antagonist on the Behavioural Symptoms of Withdrawal after Chronic Alcohol Administration in Mice.

    PubMed

    Arora, Shivani; Vohora, Divya

    2016-08-01

    As an addictive drug, alcohol produces withdrawal symptoms if discontinued abruptly after chronic use. Clonidine (CLN), a partial α2 -adrenergic agonist, and mirtazapine (MRT), an antagonist of α2 -adrenoceptor, both clinically aid alcohol withdrawal. Considering different mechanisms of action of the two drugs, this study was designed to see how far these two mechanistically different drugs differ in their ability to decrease the severity of ethanol withdrawal syndrome. The effect of CLN and MRT on ethanol withdrawal-induced anxiety, depression and memory impairment was analysed using EPM, FST and PAR tests, respectively. Animals received distilled water, ethanol and/or either of the drugs (CLN and MRT) in different doses. Relapse to alcohol use was analysed by CPP test. Animals received ethanol as a conditioning drug and distilled water, CLN or MRT as test drug. CLN and MRT both alleviated anxiety in a dose-dependent manner. MRT (4 mg/kg) was more effective than CLN (0.1 mg/kg) in ameliorating the anxiogenic effect of alcohol withdrawal. However, CLN treatment increased depression. It significantly decreased swimming time and increased immobility time, whereas MRT treatment decreased immobility time and increased climbing and swimming time during abstinence. The effect was dose dependent for both drugs. The results of PAR test show that CLN treatment worsens working memory. Significant increase in SDE and TSZ and decrease in SDL were observed in CLN-treated animals. MRT treatment, on the other hand, improved working memory at both doses. Further, both CLN and MRT alleviated craving. A significant decrease in time spent in the ethanol-paired chamber was seen. MRT treatment at both doses showed better effect than CLN in preventing the development of preference in CPP test. These findings indicate a potential therapeutic use and better profile of mirtazapine over clonidine in improving memory, as well as in alleviating depression, anxiety and craving associated

  15. Volatile compounds analysis and antioxidant, antimicrobial and cytotoxic activities of Mindium laevigatum

    PubMed Central

    Ebrahimabadi, Abdolrasoul Haghir; Movahedpour, Mohammad Mahdi; Batooli, Hossain; Ebrahimabadi, Ebrahim Haghir; Mazoochi, Asma; Qamsari, Maryam Mobarak

    2016-01-01

    Objective(s): Mindium laevigatum is an endemic plant of Iran and Turkey and is widely used as blood purifier, antiasthma and antidyspnea in traditional medicine. Chemical composition of volatile materials of the plant and its antioxidant, antimicrobial and cytotoxic activities were reported in this study. Materials and Methods: Simultaneous distillation-extraction (SDE) and GC-Mass-FID analysis were used for the plant volatile materials chemical composition identification and quantification. Several antioxidant tests including DPPH radical scavenging, hydrogen peroxide scavenging, reducing power determination, β-carotene-linoleic acid and total phenolic content tests were used for antioxidant activity evaluation. Antimicrobial and anticancer activities were also estimated using microbial strains, cancer cell lines and brine shrimp larva. Result: s: GC-Mass-FID analysis of volatile samples showed a total of 74 compounds of which palmitic acid (7.4-33.7%), linoleic acid (6.6-18.6%), heneicosane (1.3-9.6%) and myristic acid (1.4-6.0%) were detected as main volatile components. Moderate to good results were recorded for the plant in β-carotene-linoleic acid test. Total phenolic content of the extracts as gallic acid equivalents were estimated in the range of 15.7 to 79.6 μg/mg. Some microbial strains showed moderate sensitivities to plant extracts. Brine shrimp lethality test and cytotoxic cancer cell line assays showed mild cytotoxic activities for the plant. Conclusion: Moderate to good antioxidant activities in β-carotene-linoleic acid test and presence of considerable amounts of unsaturated hydrocarbons may explain the plant traditional use in asthma and dyspnea. These findings also candidate it as a good choice for investigating its possible modern medical applications. PMID:28096967

  16. Determination of nonylphenol isomers in landfill leachate and municipal wastewater using steam distillation extraction coupled with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry

    USGS Publications Warehouse

    Zhang, Caixiang; Eganhouse, Robert P.; Pontolillo, James; Cozzarelli, Isabelle M.; Wang, Yanxin

    2012-01-01

    4-Nonylphenols (4-NPs) are known endocrine disruptors and by-products of the microbial degradation of nonylphenol polyethoxylate surfactants. One of the challenges to understanding the toxic effects of nonylphenols is the large number of isomers that may exist in environmental samples. In order to attribute toxic effects to specific compounds, a method is needed for the separation and quantitation of individual nonylphenol isomers. The pre-concentration methods of solvent sublimation, solid-phase extraction or liquid–liquid extraction prior to chromatographic analysis can be problematic because of co-extraction of thousands of compounds typically found in complex matrices such as municipal wastewater or landfill leachate. In the present study, steam distillation extraction (SDE) was found to be an effective pre-concentration method for extraction of 4-NPs from leachate and wastewater, and comprehensive two-dimensional gas chromatography (GC × GC) coupled with fast mass spectral data acquisition by time-of-flight mass spectrometry (ToFMS) enhanced the resolution and identification of 4-NP isomers. Concentrations of eight 4-NP isomers were determined in leachate from landfill cells of different age and wastewater influent and effluent samples. 4-NP isomers were about 3 times more abundant in leachate from the younger cell than the older one, whereas concentrations in wastewater effluent were either below detection limits or <1% of influent concentrations. 4-NP isomer distribution patterns were found to have been altered following release to the environment. This is believed to reflect isomer-specific degradation and accumulation of 4-NPs in the aquatic environment.

  17. Evaluation of proton-conducting membranes for use in a sulfur dioxide depolarized electrolyzer

    NASA Astrophysics Data System (ADS)

    Elvington, Mark C.; Colón-Mercado, Héctor; McCatty, Steve; Stone, Simon G.; Hobbs, David T.

    The chemical stability, sulfur dioxide transport, ionic conductivity, and electrolyzer performance have been measured for several commercially available and experimental proton exchange membranes (PEMs) for use in a sulfur dioxide depolarized electrolyzer (SDE). The SDEs function is to produce hydrogen by using the Hybrid Sulfur (HyS) Process, a sulfur-based electrochemical/thermochemical hybrid cycle. Membrane stability was evaluated using a screening process where each candidate PEM was heated at 80 °C in 60 wt% H 2SO 4 for 24 h. Following acid exposure, chemical stability for each membrane was evaluated by FTIR using the ATR sampling technique. Membrane SO 2 transport was evaluated using a two-chamber permeation cell. SO 2 was introduced into one chamber whereupon SO 2 transported across the membrane into the other chamber and oxidized to H 2SO 4 at an anode positioned immediately adjacent to the membrane. The resulting current was used to determine the SO 2 flux and SO 2 transport. Additionally, membrane electrode assemblies (MEAs) were prepared from candidate membranes to evaluate ionic conductivity and selectivity (ionic conductivity vs. SO 2 transport) which can serve as a tool for selecting membranes. MEAs were also performance tested in a HyS electrolyzer measuring current density vs. a constant cell voltage (1 V, 80 °C in SO 2 saturated 30 wt% H 2SO 4). Finally, candidate membranes were evaluated considering all measured parameters including SO 2 flux, SO 2 transport, ionic conductivity, HyS electrolyzer performance, and membrane stability. Candidate membranes included both PFSA and non-PFSA polymers and polymer blends of which the non-PFSA polymers, BPVE-6F and PBI, showed the best selectivity.

  18. Introduction to TETHYS—an interdisciplinary GIS database for studying continental collisions

    NASA Astrophysics Data System (ADS)

    Khan, S. D.; Flower, M. F. J.; Sultan, M. I.; Sandvol, E.

    2006-05-01

    The TETHYS GIS database is being developed as a way to integrate relevant geologic, geophysical, geochemical, geochronologic, and remote sensing data bearing on Tethyan continental plate collisions. The project is predicated on a need for actualistic model 'templates' for interpreting the Earth's geologic record. Because of their time-transgressive character, Tethyan collisions offer 'actualistic' models for features such as continental 'escape', collision-induced upper mantle flow magmatism, and marginal basin opening, associated with modern convergent plate margins. Large integrated geochemical and geophysical databases allow for such models to be tested against the geologic record, leading to a better understanding of continental accretion throughout Earth history. The TETHYS database combines digital topographic and geologic information, remote sensing images, sample-based geochemical, geochronologic, and isotopic data (for pre- and post-collision igneous activity), and data for seismic tomography, shear-wave splitting, space geodesy, and information for plate tectonic reconstructions. Here, we report progress on developing such a database and the tools for manipulating and visualizing integrated 2-, 3-, and 4-d data sets with examples of research applications in progress. Based on an Oracle database system, linked with ArcIMS via ArcSDE, the TETHYS project is an evolving resource for researchers, educators, and others interested in studying the role of plate collisions in the process of continental accretion, and will be accessible as a node of the national Geosciences Cyberinfrastructure Network—GEON via the World-Wide Web and ultra-high speed internet2. Interim partial access to the data and metadata is available at: http://geoinfo.geosc.uh.edu/Tethys/ and http://www.esrs.wmich.edu/tethys.htm. We demonstrate the utility of the TETHYS database in building a framework for lithospheric interactions in continental collision and accretion.

  19. Gene Expression Profiling of Dendritic Cells in Different Physiological Stages under Cordyceps sinensis Treatment

    PubMed Central

    Li, Chia-Yang; Chiang, Chi-Shiun; Cheng, Wei-Chung; Wang, Shu-Chi; Cheng, Hung-Tsu; Chen, Chaang-Ray; Shu, Wun-Yi; Tsai, Min-Lung; Hseu, Ruey-Shyang; Chang, Cheng-Wei; Huang, Chao-Ying; Fang, Shih-Hua; Hsu, Ian C.

    2012-01-01

    Cordyceps sinensis (CS) has been commonly used as herbal medicine and a health supplement in China for over two thousand years. Although previous studies have demonstrated that CS has benefits in immunoregulation and anti-inflammation, the precise mechanism by which CS affects immunomodulation is still unclear. In this study, we exploited duplicate sets of loop-design microarray experiments to examine two different batches of CS and analyze the effects of CS on dendritic cells (DCs), in different physiology stages: naïve stage and inflammatory stage. Immature DCs were treated with CS, lipopolysaccharide (LPS), or LPS plus CS (LPS/CS) for two days, and the gene expression profiles were examined using cDNA microarrays. The results of two loop-design microarray experiments showed good intersection rates. The expression level of common genes found in both loop-design microarray experiments was consistent, and the correlation coefficients (Rs), were higher than 0.96. Through intersection analysis of microarray results, we identified 295 intersecting significantly differentially expressed (SDE) genes of the three different treatments (CS, LPS, and LPS/CS), which participated mainly in the adjustment of immune response and the regulation of cell proliferation and death. Genes regulated uniquely by CS treatment were significantly involved in the regulation of focal adhesion pathway, ECM-receptor interaction pathway, and hematopoietic cell lineage pathway. Unique LPS regulated genes were significantly involved in the regulation of Toll-like receptor signaling pathway, systemic lupus erythematosus pathway, and complement and coagulation cascades pathway. Unique LPS/CS regulated genes were significantly involved in the regulation of oxidative phosphorylation pathway. These results could provide useful information in further study of the pharmacological mechanisms of CS. This study also demonstrates that with a rigorous experimental design, the biological effects of a complex

  20. Hypoglycemic activity of dried extracts of Bauhinia forficata Link.

    PubMed

    da Cunha, A M; Menon, S; Menon, R; Couto, A G; Bürger, C; Biavatti, M W

    2010-01-01

    Leaves of the pantropical genus Bauhinia (Fabaceae) are known popularly as cow's foot, due to their unique characteristic bilobed aspect. The species Bauhinia forficata (Brazilian Orchid-tree) is widely used in folk medicine as an antidiabetic. The present work investigates the hypoglycemic activity of the dried extracts of Bauhinia forficata leaves in vivo, as well as the influence of the drying and granulation processes on this activity. The fluid extract was dried to generate oven-dried (ODE), spray-dried (SDE) and wet granulation (WGE) extracts, with the aid of colloidal silicon dioxide and/or cellulose:lactose mixture. The dried extracts were characterized by spectrophotometric, chromatographic and photo microscopy image analysis. 200 mg/kg body wt., p.o. of each dried product were administered orally to male Wistar rats over 7 days old, for biomonitoring of the hypoglycemic activity profile. The effect of the extracts was studied in STZ-induced diabetic rats. After 7 days of treatment, fasting glucose was determined, and the livers were removed, dried on tissue paper, weighed, and stored at -20 degrees C to estimate hepatic glycogen. Our results show that spray-drying or oven-drying processes applied to B. forficata extracts did not significantly alter its flavonoid profile or its hypoglycemic activity. Indeed, the dried extracts of B. forficata act differently from glibenclamide. Despite the lower active content in WGE, because of the higher concentration of adjuvants, the use of the granulation process improved the manufacturing properties of the ODE, making this material more appropriate for use in tablets or capsules.

  1. Optimal control of systems governed by differential equations with applications in air traffic management and systems biology

    NASA Astrophysics Data System (ADS)

    Raffard, Robin L.

    proves to greatly speed up the discovery of the system. We finally show applications of the method to SDE driven systems, through benchmark examples in engineering and finance.

  2. Sedimentation dynamics and equilibrium profiles in multicomponent mixtures of colloidal particles.

    PubMed

    Spruijt, E; Biesheuvel, P M

    2014-02-19

    In this paper we give a general theoretical framework that describes the sedimentation of multicomponent mixtures of particles with sizes ranging from molecules to macroscopic bodies. Both equilibrium sedimentation profiles and the dynamic process of settling, or its converse, creaming, are modeled. Equilibrium profiles are found to be in perfect agreement with experiments. Our model reconciles two apparently contradicting points of view about buoyancy, thereby resolving a long-lived paradox about the correct choice of the buoyant density. On the one hand, the buoyancy force follows necessarily from the suspension density, as it relates to the hydrostatic pressure gradient. On the other hand, sedimentation profiles of colloidal suspensions can be calculated directly using the fluid density as apparent buoyant density in colloidal systems in sedimentation-diffusion equilibrium (SDE) as a result of balancing gravitational and thermodynamic forces. Surprisingly, this balance also holds in multicomponent mixtures. This analysis resolves the ongoing debate of the correct choice of buoyant density (fluid or suspension): both approaches can be used in their own domain. We present calculations of equilibrium sedimentation profiles and dynamic sedimentation that show the consequences of these insights. In bidisperse mixtures of colloids, particles with a lower mass density than the homogeneous suspension will first cream and then settle, whereas particles with a suspension-matched mass density form transient, bimodal particle distributions during sedimentation, which disappear when equilibrium is reached. In all these cases, the centers of the distributions of the particles with the lowest mass density of the two, regardless of their actual mass, will be located in equilibrium above the so-called isopycnic point, a natural consequence of their hard-sphere interactions. We include these interactions using the Boublik-Mansoori-Carnahan-Starling-Leland (BMCSL) equation of

  3. Establishment and characterization of duck embryo epithelial (DEE) cell line and its use as a new approach toward DHAV-1 propagation and vaccine development.

    PubMed

    Wang, Wenxiu; Said, Abdelrahman; Wang, Yan; Fu, Qiang; Xiao, Yueqiang; Lv, Sufang; Shen, Zhiqiang

    2016-02-02

    The primary cell culture was derived from duck embryonic tissue, digested with collagenase type I. The existence of cell colonies with epithelial-like morphology, named duck embryo epithelial (DEE), were purified and optimally maintained at 37°C in M199 medium supplemented with 5% fetal bovine serum. The purified cells were identified as epithelial cell line by detecting Keratin-18 expression using immunofluorescence assay. Our findings demonstrated that DEE cell line can be propagated in culture with (i) a great capacity to adhere, (ii) a great proliferation activity, and (iii) a population doubling time of approximately 18h. Chromosomal features of the DEE cell line were remained constant after the 50th passage. Further characterizations of DEE cell line showed that cell line can normally be grown even after several passages and never converted to tumorigenic cells either in vitro or in vivo study. Susceptibility of DEE cell line was determined for transfection and duck hepatitis A type 1 virus (DHAV-1)-infection. Interestingly, the 50% egg lethal dose (ELD50) of the propagated virus in DEE cell line was higher than ELD50 of the propagated virus in embryonated eggs. Finally, DEE cell line was evaluated to be used as a candidate for DHAV-1 vaccine development. Our results showed that the propagated DHAV-1 vaccine strain SDE in DEE cell line was able to protect ducklings against DHAV-1 challenge. Taken together, our findings suggest that the DEE cell line can serve as a valuable tool for DHAV-1 propagation and vaccine production.

  4. A synthetic design environment for ship design

    NASA Technical Reports Server (NTRS)

    Chipman, Richard R.

    1995-01-01

    Rapid advances in computer science and information system technology have made possible the creation of synthetic design environments (SDE) which use virtual prototypes to increase the efficiency and agility of the design process. This next generation of computer-based design tools will rely heavily on simulation and advanced visualization techniques to enable integrated product and process teams to concurrently conceptualize, design, and test a product and its fabrication processes. This paper summarizes a successful demonstration of the feasibility of using a simulation based design environment in the shipbuilding industry. As computer science and information science technologies have evolved, there have been many attempts to apply and integrate the new capabilities into systems for the improvement of the process of design. We see the benefits of those efforts in the abundance of highly reliable, technologically complex products and services in the modern marketplace. Furthermore, the computer-based technologies have been so cost effective that the improvements embodied in modern products have been accompanied by lowered costs. Today the state-of-the-art in computerized design has advanced so dramatically that the focus is no longer on merely improving design methodology; rather the goal is to revolutionize the entire process by which complex products are conceived, designed, fabricated, tested, deployed, operated, maintained, refurbished and eventually decommissioned. By concurrently addressing all life-cycle issues, the basic decision making process within an enterprise will be improved dramatically, leading to new levels of quality, innovation, efficiency, and customer responsiveness. By integrating functions and people with an enterprise, such systems will change the fundamental way American industries are organized, creating companies that are more competitive, creative, and productive.

  5. Novel determination of radon-222 velocity in deep subsurface rocks, and the feasibility to using radon as an earthquake precursor

    NASA Astrophysics Data System (ADS)

    Zafrir, Hovav; Benhorin, Yochy; Malik, Uri; Chemo, Chaim

    2016-04-01

    An enhanced radon monitoring system was designed in order to study shallow versus deep subsurface processes affecting the appearance of radon anomalies. The method is based on the assumption that the climatic influence is limited since its energy decreases with the decrease in thickness of the geological cover whereby its effect is reduced to a negligible value at depth. Hence, lowering gamma and alpha detectors into deep boreholes and monitoring their temporal variations relative to a reference couple at shallow depths of 10-40 m eliminates the ambient thermal and pressure-induced contribution from the total radon time series. It allows highlighting the residual portion of the radon signals that might be associated with the geodynamic processes. The primary technological key is the higher sensitivity of the gamma detectors - in comparison to the solid-state alpha detectors, which are also suitable for threading into narrow boreholes in parallel to the narrow gamma detector (Zafrir et al., 2013*). The unique achievements of the novel system that was installed at the Sde Eliezer site close to the Hula Valley western border fault (HWBF) in northern Israel are: a) Determination, for the first time, of the radon movement velocity within rock layers at depths of several tens of meters, namely, 25 m per hour on average; b) Distinguishing between the diurnal periodical effect of the ambient temperature and the semi-diurnal effect of the ambient pressure on the radon temporal spectrum; c) Identification of a radon random pre-seismic anomaly preceding the Nuweiba, M 5.5 earthquake of 27 June 2015 that occurred within Dead Sea Fault Zone. * Zafrir, H., Barbosa, S.M. and Malik, U., 2013. Differentiation between the effect of temperature and pressure on radon within the subsurface geological media, Radiat. Meas., 49, 39-56. doi:10.1016/j.radmeas.2012.11.019.

  6. REVIEW: Going beyond the LIBOR model

    NASA Astrophysics Data System (ADS)

    Javaheri, Alireza

    2004-06-01

    Having a mostly equity derivatives background, I was concerned that I would find this book too complex. I therefore started reading it with misgiving. However, the first thing Rebonato does is to give a concise yet thorough history of the evolution of interest-rate derivatives. Starting with the famous Black model, one assumes that either the forward rate or the swap rate (fixed rate) is log-normal. Using the forward rate would allow us to deal with the `pull to par' phenomenon: the fact that the price of a bond must be par at its maturity. Note that, as Rebonato points out, some were even ignoring this phenomenon and using the Black - Scholes pricing formula. The justification was that in their cases, the bond maturity was far beyond the option maturity. This model has been, and still is, popular due to its simplicity and the fact that it allows us to price many vanilla instruments (caps and swaptions) exactly. However, as Rebonato keeps telling us, this exact replication is deceiving. Indeed they take place under different probability measures and, therefore, the replications are inconsistent with one another. This means that if you were to price an exotic derivative with multiple call dates or exercise dates, you would not have one internally plausible framework to do so. Then came the short-rate models such as the Vasicek model or the Cox, Ingersoll and Ross (CIR) model. They treated the instantaneous short interest rate as the driving force of the term structure. This short rate therefore followed a stochastic differential equation (SDE) of its own which was mean reverting. However, these models did not guarantee matching of the market. An extension to these models, mainly by Hull and White on the one hand and Jamshidian on the other hand, was the following: make the drift term a time-dependent deterministic function that we would resolve in order to match various vanilla prices. But once again, the same issue raises its ugly head. If we are pricing non

  7. Impact of stochasticity in immigration and reintroduction on colonizing and extirpating populations.

    PubMed

    Rajakaruna, Harshana; Potapov, Alexei; Lewis, Mark

    2013-05-01

    A thorough quantitative understanding of populations at the edge of extinction is needed to manage both invasive and extirpating populations. Immigration can govern the population dynamics when the population levels are low. It increases the probability of a population establishing (or reestablishing) before going extinct (EBE). However, the rate of immigration can be highly fluctuating. Here, we investigate how the stochasticity in immigration impacts the EBE probability for small populations in variable environments. We use a population model with an Allee effect described by a stochastic differential equation (SDE) and employ the Fokker-Planck diffusion approximation to quantify the EBE probability. We find that, the effect of the stochasticity in immigration on the EBE probability depends on both the intrinsic growth rate (r) and the mean rate of immigration (p). In general, if r is large and positive (e.g. invasive species introduced to favorable habitats), or if p is greater than the rate of population decline due to the demographic Allee effect (e.g., effective stocking of declining populations), then the stochasticity in immigration decreases the EBE probability. If r is large and negative (e.g. endangered populations in unfavorable habitats), or if the rate of decline due to the demographic Allee effect is much greater than p (e.g., weak stocking of declining populations), then the stochasticity in immigration increases the EBE probability. However, the mean time for EBE decreases with the increasing stochasticity in immigration with both positive and negative large r. Thus, results suggest that ecological management of populations involves a tradeoff as to whether to increase or decrease the stochasticity in immigration in order to optimize the desired outcome. Moreover, the control of invasive species spread through stochastic means, for example, by stochastic monitoring and treatment of vectors such as ship-ballast water, may be suitable strategies

  8. A Web-Based GIS for Reporting Water Usage in the High Plains Underground Water Conservation District

    NASA Astrophysics Data System (ADS)

    Jia, M.; Deeds, N.; Winckler, M.

    2012-12-01

    The High Plains Underground Water Conservation District (HPWD) is the largest and oldest of the Texas water conservation districts, and oversees approximately 1.7 million irrigated acres. Recent rule changes have motivated HPWD to develop a more automated system to allow owners and operators to report well locations, meter locations, meter readings, the association between meters and wells, and contiguous acres. INTERA, Inc. has developed a web-based interactive system for HPWD water users to report water usage and for the district to better manage its water resources. The HPWD web management system utilizes state-of-the-art GIS techniques, including cloud-based Amazon EC2 virtual machine, ArcGIS Server, ArcSDE and ArcGIS Viewer for Flex, to support web-based water use management. The system enables users to navigate to their area of interest using a well-established base-map and perform a variety of operations and inquiries against their spatial features. The application currently has six components: user privilege management, property management, water meter registration, area registration, meter-well association and water use report. The system is composed of two main databases: spatial database and non-spatial database. With the help of Adobe Flex application at the front end and ArcGIS Server as the middle-ware, the spatial feature geometry and attributes update will be reflected immediately in the back end. As a result, property owners, along with the HPWD staff, collaborate together to weave the fabric of the spatial database. Interactions between the spatial and non-spatial databases are established by Windows Communication Foundation (WCF) services to record water-use report, user-property associations, owner-area associations, as well as meter-well associations. Mobile capabilities will be enabled in the near future for field workers to collect data and synchronize them to the spatial database. The entire solution is built on a highly scalable cloud

  9. Application of The Stochastic Particle Tracking Model To Evaluate Particle Movement Uncertainty in Extreme Flows

    NASA Astrophysics Data System (ADS)

    Tsai, C.; Lin, E.

    2014-12-01

    In this study, modeling of suspended sediment particle movement in extreme flows is proposed by stochastic particle tracking modeling approaches. The proposed stochastic model is governed by a stochastic differential equation (SDE) composed of two random processes (a Wiener process and a Poisson process), and a random variable (i.e., flow magnitude) simulated by the extreme value Type I distribution. An extreme flow is defined as a hydrologic flow event (such as a flash flood) or a large flow perturbation with a low probability of occurrence and a high impact on its ambient flow environment. In the proposed particle tracking model, a random term mainly caused by fluid eddy motions is modeled as a Wiener process, while the random occurrences of a sequence of extreme flows can be modeled as a Poisson process. Following previous work by Oh and Tsai (2010)[1] and Tsai et al. (2014)[2], this study is intended to modify the jump term, which models the abrupt changes of particle position in the extreme flow environments. It is proposed that the probabilistic magnitude of extreme events can be simulated by the extreme value type I (EV I) distribution. The ensemble mean and variance of particle trajectory can be obtained from the proposed stochastic models via simulations. Our findings suggest that the ability to consider the probabilistic magnitude of extreme events can provide a more comprehensive and realistic estimate of the uncertainty of particle movement when extreme flow events occur. It is also found that the variance of particle position may be attributed to both the random magnitudes and occurrences of particle jumps in the presence of extreme flow events. It is demonstrated from this study that the proposed model can more explicitly quantify the uncertainty of particle movement by taking into considerations both the random arrival process of extreme flows and the variability of the extreme flow magnitude. [1] Oh, J. S., and Tsai, C.W.(2010). "A stochastic jump

  10. Genetic analysis of within-litter variation in piglets' birth weight using genomic or pedigree relationship matrices.

    PubMed

    Sell-Kubiak, E; Wang, S; Knol, E F; Mulder, H A

    2015-04-01

    The objective of this study was to estimate the genetic variance for within-litter variation of birth weight (BW0) using genomic (GRM) or pedigree relationship matrices (PRM) and to compare the accuracy of estimated breeding values (EBV) for within-litter variation of BW0 using GRM and PRM. The BW0 and residual variance of BW0 were modeled by the double hierarchical generalized linear model using GRM or PRM. Data came from 2 dam lines: Landrace and Large White. After editing, the data set in Landrace consisted of 748 sows with 1,938 litters and 29,430 piglets and in Large White of 989 sows with 3,320 litters and 51,818 piglets. To construct GRM, 46,466 (Landrace) and 44,826 (Large White) single nucleotide polymorphisms were used, whereas to construct PRM, 5 generations of pedigree were used. The accuracy of EBV with GRM was estimated with 8-fold cross-validation and compared to PRM. Estimated variance components were highly similar for GRM and PRM. The maternal genetic variance in residual variance of BW0 in Landrace was 0.05 with GRM and 0.06 with PRM. In Large White these were 0.04 with GRM and 0.05 with PRM. The genetic coefficient of variation (GCV SDe) was about 0.10 in both dam lines. This indicates a change of 10% in residual SD of BW0 when achieving a genetic response of 1 genetic standard deviation. The genetic correlation between birth weight and its residual variance was about 0.6 in both dam lines. The accuracies of selection for within-litter variation of birth weight were 0.35 with GRM and 0.23 with PRM in Landrace and 0.29 with GRM and 0.34 with PRM in Large White. In this case, using GRM did not significantly increase accuracies of selection. Results, however, show good opportunities to select for reduced within-litter variation of BW0. Genomic selection can increase accuracy of selection when reference populations contain at least 2,000 sows.

  11. Accelerating numerical solution of stochastic differential equations with CUDA

    NASA Astrophysics Data System (ADS)

    Januszewski, M.; Kostur, M.

    2010-01-01

    Numerical integration of stochastic differential equations is commonly used in many branches of science. In this paper we present how to accelerate this kind of numerical calculations with popular NVIDIA Graphics Processing Units using the CUDA programming environment. We address general aspects of numerical programming on stream processors and illustrate them by two examples: the noisy phase dynamics in a Josephson junction and the noisy Kuramoto model. In presented cases the measured speedup can be as high as 675× compared to a typical CPU, which corresponds to several billion integration steps per second. This means that calculations which took weeks can now be completed in less than one hour. This brings stochastic simulation to a completely new level, opening for research a whole new range of problems which can now be solved interactively. Program summaryProgram title: SDE Catalogue identifier: AEFG_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFG_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Gnu GPL v3 No. of lines in distributed program, including test data, etc.: 978 No. of bytes in distributed program, including test data, etc.: 5905 Distribution format: tar.gz Programming language: CUDA C Computer: any system with a CUDA-compatible GPU Operating system: Linux RAM: 64 MB of GPU memory Classification: 4.3 External routines: The program requires the NVIDIA CUDA Toolkit Version 2.0 or newer and the GNU Scientific Library v1.0 or newer. Optionally gnuplot is recommended for quick visualization of the results. Nature of problem: Direct numerical integration of stochastic differential equations is a computationally intensive problem, due to the necessity of calculating multiple independent realizations of the system. We exploit the inherent parallelism of this problem and perform the calculations on GPUs using the CUDA programming environment. The GPU's ability to execute

  12. An electrified dust storm over the Negev desert, Israel

    NASA Astrophysics Data System (ADS)

    Yair, Y.; Price, C. G.; Yaniv, R.; Katz, S.

    2015-12-01

    We report on atmospheric electrical measurements conducted at the Wise Observatory in Mitzpe-Ramon, Israel (30035'N, 34045'E) during a massive dust storm that occurred over the Eastern Mediterranean region on 10-11 February 2015. The event transported Saharan dust from Egypt and the Sinai Peninsula in advance of the warm front of a Cyprus low pressure system. Satellite images show the dust plume covering the Negev desert and Southern Israel and moving north. The concentrations of PM10 particles measured by the air-quality monitoring network of the Israeli Ministry of the Environment in Beer-Sheba reached values > 450 μg m-3 and AOT from the AERONET station in Sde-Boker was 1.5 on the 10th. The gradual intensification of the event reached peak values on February 11th of over 1200 μg m-3 and AOT of 1.8. This was the most severe dust event in a decade. Continuous measurements of the fair weather vertical electric field (Ez) and vertical current density (Jz) were conducted with 1 minute temporal resolution. Meteorological data was also recorded at the site. As the dust was advected over the observation site, we noted very large fluctuations in the electrical parameters. Since the onset of the dust storm, the Ez values changed between +1000 and +8000 V m-1 while the Jz fluctuated between -10 pA m2 and +20 pA m2, both on time-scales of a few minutes. These values are a significant departures from the mean fair-weather values measured at the site, which are -~200 V m-1 and ~2 pA m2. The disturbed episodes lasted for several hours on the 10th and 11th and coincided with local meteorological conditions related to the wind direction, which carried large amounts of dust particles. We interpret the rapid changes as caused by the transport of electrically charged dust. Calculation of the total electrical charge during the dust storm will be presented.

  13. Ground level ice nuclei particle measurements including Saharan dust events at a Po Valley rural site (San Pietro Capofiume, Italy)

    NASA Astrophysics Data System (ADS)

    Belosi, F.; Rinaldi, M.; Decesari, S.; Tarozzi, L.; Nicosia, A.; Santachiara, G.

    2017-04-01

    Filter-collected aerosol samples in the PM1 and PM10 fractions and particle number concentration were measured during experimental campaigns in a rural area near Bologna (Italy) in the periods 10-21 February 2014 and 19-30 May 2014. Ice nuclei particle (INP) concentrations measured off-line showed prevalently higher average values in the morning with respect to the afternoon, in the PM1 fraction with respect to PM1-10 (with the exception of the first campaign, at Sw = 1.01), and at water saturation ratio Sw = 1.01 with respect to Sw = 0.96. The aerosol in the coarse size range (1-10 μm) contributed significantly to the total INP concentration. In the first campaign, the average INP concentration in the coarse fraction was 80% of the total in the morning and 74% in the afternoon, at Sw = 1.01. In the second campaign, the contribution of the coarse size fraction to the INP number concentration was lower. On the whole, the results showed that the freezing activity of aerosol diameters larger than 1 μm needs to be measured to obtain the entire INP population. Sahara dust events (SDEs) took place during both campaigns, in the periods 17-20 February and 21-23 May 2014. Results show that the averaged particle number concentration was higher during SDE than during no-Saharan dust events. A low correlation between INP and total aerosol number concentration was generally measured, except for SDEs observed in February, in which the correlation coefficient between aerosol concentration in the coarse fraction and INP in the same range, at water supersaturation, was about 0.8. Precipitation events influenced the aerosol concentration. In the February campaign, lower values of INP and particle concentrations were measured in case of heavy rain events. During the May campaign, an average number concentration of the aerosol in the range 0.5-10 μm was slightly higher than on days when no precipitation was measured, the rainfall intensity being low. Only in a few cases did we note

  14. An electrified dust storm over the Negev desert, Israel

    NASA Astrophysics Data System (ADS)

    Yair, Yoav; Katz, Shai; Yaniv, Roy; Ziv, Baruch; Price, Colin

    2016-11-01

    We report on atmospheric electrical measurements conducted at the Wise Observatory in Mitzpe-Ramon, Israel (30°35‧N, 34°45‧E) during a large dust storm that occurred over the Eastern Mediterranean region on 10-11 February 2015. The dust was transported from the Sahara, Egypt and the Sinai Peninsula ahead of an approaching Cyprus low. Satellite images show the dust plume covering the Negev desert and Southern Israel and moving north. The concentrations of PM10 particles measured by the air-quality monitoring network of the Israeli Ministry of the Environment in Beer-Sheba reached values > 450 μg m- 3 and the AOT from the AERONET station in Sde-Boker was 1.5 on February 10th. The gradual intensification of the event reached peak concentrations on February 11th of over 1200 μg m- 3 and an AOT of 1.8. Continuous measurements of the fair weather vertical electric field (Ez) and vertical current density (Jz) were conducted at the Wise Observatory with 1 minute temporal resolution. Meteorological data was also recorded at the site. As the dust was advected over the observatory, very large fluctuations in the electrical parameters were registered. From the onset of the dust storm, the Ez values changed between + 1000 and + 8000 V m- 1 while the current density fluctuated between - 10 pA m2 and + 20 pA m2, both on time-scales of a few minutes. These values are significant departures from the average fair-weather values measured at the site, which are ~- 200 V m- 1 and ~ 2 pA m2. The disturbed episodes lasted for several hours on February 10th and the 11th and coincided with local meteorological conditions related to the wind speed and direction, which carried large amounts of dust particles over our observation station. We interpret the rapid changes as caused by the transport of electrically charged dust, carrying an excess of negative charge at lower altitudes.

  15. The Use of Geographic Information Technologies in Environmental Decision-Making in the State of Michoacan, Mexico

    NASA Astrophysics Data System (ADS)

    Teodoro, Silva García José; Gustavo, Cruz Cárdenas; Salvador, Ochoa Estrada; Franciso, Estrada Godoy; Fabian, Villalpando Barragán

    2008-05-01

    One of the most urgent issues facing the human environment, a result of current human evolution is the increase in the production of Urban Solid Waste (USW). The State of Michoacán is no exception; the presence of waste facilities in the area is a very big problem and one with a strong geographical content (Mena et al., 2006). SIGs are one tool for addressing this kind of need. A model which has been commonly used for selecting areas for the final deposit of USW, and which has obtained good results, is so-called multicriterion decision-making. It has been applied in the context of integral USW management, and has generated both a methodology for the determination of safe places for final waste deposit and an Environmental Risk Index (ERI), which fulfills the requirements indicated by the Official Mexican Norm (NOM-083-SEMARNAT-2003). The methodology consists of a quadrant analysis of 25 ha of five factors. A rank was assigned to each of the factors, and this rank was standardized according to a scale from 0 to 10 and subsequently multiplied by a weight (W) which numerically represents the degree of importance and influence of each factor in the environment. Five represented the largest impact, and two represented the smallest impact. The ERI is the sum of the five factors considered and it is represented by means of the following equation: ERI = VVw+UsUsw+FrFrw+ln lnw+Zi Ziw, where ERI is the Environmental Risk Index, V Vw is the aquifer vulnerability, Us Usw represents the use of the soil, Fr Frw refers to the fracturing density, ln lnw represents the domain of the urban and industrial infrastructure, and Zi Ziw refers to flood zones. This was shown to be successful in different regions of Michoacán State, such as the Bajío area, the Paísde la Mariposa Monarca and Tierra Caliente. Another example is its application in the hydrogeologic context, which generated the Aquifer Veda index (a restriction diagram for the opening of new exploitations), and which is

  16. The Ice Selective Inlet: a novel technique for exclusive extraction of pristine ice crystals in mixed-phase clouds

    NASA Astrophysics Data System (ADS)

    Kupiszewski, P.; Weingartner, E.; Vochezer, P.; Schnaiter, M.; Bigi, A.; Gysel, M.; Rosati, B.; Toprak, E.; Mertes, S.; Baltensperger, U.

    2015-08-01

    proof of concept of the inlet design. In this work we present the setup of the ISI, including the modelling and laboratory characterization of its components, as well as field measurements demonstrating the ISI performance and validating the working principle of the inlet. Finally, measurements of biological aerosol during a Saharan dust event (SDE) are presented, showing a first indication of enrichment of bio-material in sub-2 μm ice residuals.

  17. CHARACTERIZATION TESTING AND ANALYSIS OF SINGLE CELL SO2 DEPOLARIZED ELECTROLYZER

    SciTech Connect

    Steimke, J; Timothy Steeper, T

    2006-09-15

    This document reports work performed at the Savannah River National Laboratory (SRNL) that further develops the use of a proton exchange membrane or PEM-type electrochemical cell to produce hydrogen via SO{sub 2}-depolarized water electrolysis. This work was begun at SRNL in 2005. This research is valuable in achieving the ultimate goal of an economical hydrogen production process based on the Hybrid Sulfur (HyS) Cycle. The HyS Process is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by water-splitting. Like all other sulfur-based cycles, HyS utilizes the high temperature thermal decomposition of sulfuric acid to produce oxygen. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Sulfur dioxide is oxidized at the anode, producing sulfuric acid that is sent to the acid decomposition portion of the cycle. The focus of this work was to conduct single cell electrolyzer tests in order to prove the concept of SO{sub 2}-depolarization and to determine how the results can be used to evaluate the performance of key components of the HyS Process. A test facility for conducting SO{sub 2}-depolarized electrolyzer (SDE) testing was designed, constructed and commissioned. The maximum cell current is 50 amperes, which is equivalent to a hydrogen production rate of approximately 20 liters per hour. Feed to the anode of the electrolyzer is sulfuric acid solutions containing dissolved sulfur dioxide. The partial pressure of sulfur dioxide may be varied in the range of 1 to 6 atm (15 to 90 psia). Temperatures may be controlled in the range from ambient to 80 C. Hydrogen generated at the cathode of the cell is collected for the purpose of flow measurement and composition analysis. The test facility proved to be easy to

  18. From dust to varnish: Geochemical constraints on rock varnish formation in the Negev Desert, Israel

    NASA Astrophysics Data System (ADS)

    Goldsmith, Yonaton; Stein, Mordechai; Enzel, Yehouda

    2014-02-01

    its varnish formation, Mn2+ is oxidized by one of the mechanisms presented by Morgan (2005). Morgan's data pertains to the rate in which Mn2+ is removed from the solution, and not to the rate of precipitation of Mn-oxides; the assumption used here is that the formation rate of Mn oxides is equal or faster than the removal rate of Mn2+, and therefore it is governed by the removal rate of Mn2+ from the solution. The efficiency of dissolution and deposition of Mn in varnish is unknown. Therefore, our calculations are based on full utilization (i.e., all Mn in the dust is transformed into Mn oxides in the varnish). Dust is abundant and its supply does not limit the process: this assumption is probably valid for deserts in general and more so to the central and southern Negev. Oxidation can occur only when moisture is available. The main moisture contributor to the Negev varnish is most likely dew (Goldsmith et al., 2012). To quantify the annual dew amounts, we used Zangvil (1996) data of an average of ˜1400 h/yr, which was measured over a six year period (at Sde Boker located between Divshon I and Nahal Boker in Fig. 1). For the following calculations, we used sites located in the central Negev, where it can be assumed that these sites experienced a similar moister regime as in Sde Boker. Morgan (2005) calculated the half-life for oxidation of Mn2+ in an aqueous environment. As stated above, these conditions prevail during ˜1400 h yr-1. With a Mn concentration in the dust of ˜500 ppm, the maximum amounts of Mn that would accumulate a year is: 35,000, 490, and 36 ppmMn yr-1 via bacterial oxidation, metal oxide catalysts, and homogenous solution oxidation, respectively.To estimate accumulation rates of Mn in the varnish, we calculated the total amount of Mn (MnTOT) in the measured profiles of the varnish by using an integral of the area under the graphs of [Mn]/depth (% atom/μm) (see appendix in Goldsmith, 2011). The MnTOT was divided by 9000 yr (the time interval since

  19. Integrated data management system of Korean marine geological and geophysical data

    NASA Astrophysics Data System (ADS)

    Baek, Sang-Ho; Kim, Sung-Dae; Park, Soo-Young; Park, Hyuk-Min; Lee, Jin-Hee

    2013-04-01

    maps, some of the submitted data were excluded from collected data files. Finally we could establish the integrated DB system contains 4,522 seismic data files, 14,189,005 magnetic data, 3,515,831 gravity data, 1,638 surface sediment data and 9,023 core sediment data. Oracle RDBMS was adopted to manage the collected data and Oracle 11g was installed on UNIX system. Considering the data characteristics, DB structure was designed and 38 DB tables were created in the DB system. All data was stored into DB system using Oracle SQL Loader. The geographic information system was introduced to manage spatial information of oceanographic data and provide data effectively using map interface. All collected position data of the marine geological data and geophysical data was converted to Esri shapefile format using UTM coordination system based on WGS 84 datum. ArcGIS desktop software was utilized to import position data from ASCII files, manipulate data and produce shapefile data. To save and manage shapefile data systematically, a GeoDatabse was devloped using the Oracle RDBMS and ArcGIS SDE (Spatial Database Engine). Total 40 DB tables were created in the Oracle 11g and all shapefile data was stored into DB system. We made the linkage between data of the GeoDatabase and data of the Archive DB for comprephensive data and information provision. A GIS application based on ArcGIS Engine was developed to provide geographic information and observed values of oceanogrpahic data. The window of the GIS application consists of map window, image viewer, graph viewer and SEG-Y viewer.

  20. Detection of Saharan dust and biomass burning events using near-real-time intensive aerosol optical properties in the north-western Mediterranean

    NASA Astrophysics Data System (ADS)

    Ealo, Marina; Alastuey, Andrés; Ripoll, Anna; Pérez, Noemí; Cruz Minguillón, María; Querol, Xavier; Pandolfi, Marco

    2016-10-01

    The study of Saharan dust events (SDEs) and biomass burning (BB) emissions are both topics of great scientific interest since they are frequent and important polluting scenarios affecting air quality and climate. The main aim of this work is evaluating the feasibility of using near-real-time in situ aerosol optical measurements for the detection of these atmospheric events in the western Mediterranean Basin (WMB). With this aim, intensive aerosol optical properties (SAE: scattering Ångström exponent, AAE: absorption Ångström exponent, SSAAE: single scattering albedo Ångström exponent and g: asymmetry parameter) were derived from multi-wavelength aerosol light scattering, hemispheric backscattering and absorption measurements performed at regional (Montseny; MSY, 720 m a.s.l.) and continental (Montsec; MSA, 1570 m a.s.l.) background sites in the WMB. A sensitivity study aiming at calibrating the measured intensive optical properties for SDEs and BB detection is presented and discussed. The detection of SDEs by means of the SSAAE parameter and Ångström matrix (made up by SAE and AAE) depended on the altitude of the measurement station and on SDE intensity. At MSA (mountain-top site) SSAAE detected around 85 % of SDEs compared with 50 % at the MSY station, where pollution episodes dominated by fine anthropogenic particles frequently masked the effect of mineral dust on optical properties during less intense SDEs. Furthermore, an interesting feature of SSAAE was its capability to detect the presence of mineral dust after the end of SDEs. Thus, resuspension processes driven by summer regional atmospheric circulations and dry conditions after SDEs favoured the accumulation of mineral dust at regional level having important consequences for air quality. On average, SAE, AAE and g ranged between -0.7 and 1, 1.3 and 2.5 and 0.5 and 0.75 respectively during SDEs. Based on the aethalometer model, BB contribution to equivalent black carbon (BC) accounted for 36 and 40

  1. Satellite Altimetry And Radiometry for Inland Hydrology, Coastal Sea-Level And Environmental Studies

    NASA Astrophysics Data System (ADS)

    Tseng, Kuo-Hsin

    Resolution Imaging Spectroradiometer (MODIS). Meanwhile, the computation of surface level variation at identified water region matches well with nearby in situ gauge data. In second application we use synergistic altimetry and remote sensing data to characterize water bodies’ variation in Poyang Lake, China. The accurate measurement of lake surface variation dominates the potential extent of habitat for certain Oncomelania snails to reside, while this species of snail transmits certain infectious disease (ID) Schistosomiasis. We use Envisat and various MODIS products to obtain former revealed geophysical factors that affect snail’s ecosystem, to simulate favorable residence for the intermediating snail. The simulation of habitat extent matches fairly well with the official estimation reported from China’s health administration during 2002-2007. The third application, with multispectral reflectance data given by the MERIS onboard Envisat, is to demonstrate the potential capability in quantifying the harmful algal bloom (HAB) alongshore Lake Erie, in regard to certain cyanobacteria (i.e. Microcystis) that endanger water qualities. After comparing with the in situ laboratory analysis, a correlation coefficient, standard deviation of error (SDE), and a bias are obtained in between. Finally, we display the lake level variation using Envisat altimetry and MODIS water temperature product, to demonstrate the possibility in modelling the onset timing of toxic cyanobacteria bloom using spaceborne observations.

  2. Atmospheric Electricity Effects of Eastern Mediterranean Dust Storms

    NASA Astrophysics Data System (ADS)

    Katz, Shai; Yair, Yoav; Yaniv, Roy; Price, Colin

    2016-04-01

    We present atmospheric electrical measurements conducted at the Wise Observatory (WO) in Mizpe-Ramon (30035'N, 34045'E) and Mt. Hermon (30024'N, 35051'E), Israel, during two massive and unique dust storms that occurred over the Eastern Mediterranean region on February 10-11 and September 08-12, 2015. The first event transported Saharan dust from Egypt and the Sinai Peninsula in advance of a warm front of a Cyprus low pressure system. In the second event, dust particles were transported from the Syrian desert, which dominates the north-east border with Iraq, through flow associated with a shallow Persian trough system. In both events the concentrations of PM10 particles measured by the air-quality monitoring network of the Israeli Ministry of the Environment in Beer-Sheba reached values > 2200 μg m-3. Aerosol Optical Thickness (AOT) obtained from the AERONET station in Sde-Boker reached values up to 4.0. The gradual intensification of the first event reached peak values on the February 11th > 1200 μg m-3 and an AOT ~ 1.8, while the second dust storm commenced on September 8th with a sharp increase reaching peak values of 2225 μg m-3 and AOT of 4.0. Measurements of the fair weather vertical electric field (Ez) and of the vertical current density (Jz) were conducted continuously with a 1 minute temporal resolution. During the February event, very large fluctuations in the electrical parameters were measured at the WO. The Ez values changed between +1000 and +8000 V m-1 while the Jz fluctuated between -10 and +20 pA m-2 (this is an order of magnitude larger compared to the fair weather current density of ~2 pA m-2. In contrast, during the September event, Ez values registered at WO were between -430 and +10 V m-1 while the Jz fluctuated between -6 and +3 pA m2. For the September event the Hermon site showed Ez and Jz values fluctuating between -460 and +570 V m-1 and -14.5 and +18 pA m-2 respectively. The electric field and current variability, amplitude and the

  3. Dichroic Liquid Crystal Displays

    NASA Astrophysics Data System (ADS)

    Bahadur, Birendra

    * Effect of Thickness * Impact of Order Parameter * Impact of the Host * Impact of Polarizer * Colour Applications * Multiplexing * QUARTER WAVE PLATE DICHROIC DISPLAYS * Operational Principle and Display Configuration11-13 * Electro-Optical Performance * DYE-DOPED TN DISPLAYS * Threshold Characteristic, Contrast Ratio and Switching Speed * PHASE CHANGE EFFECT DICHROIC LCDs * Theoretical Background * Threshold Characteristic and Molecular Orientation * MOLECULAR ORIENTATION DURING FIELD-INDUCED PHASE TRANSITION WITH HOMOGENEOUS WALL ALIGNMENT * MOLECULAR ORIENTATION DURING FIELD-INDUCED PHASE TRANSITION WITH HOMEOTROPIC WALL ALIGNMENT * Contrast Ratio, Transmission, Brightness and Switching Speed3,7,10,198-214 * Memory or Reminiscent Contrast * Electro-optical Performance vs. Temperature * Multiplexing Phase Change Dichroic LCDs * DOUBLE CELL DICHROIC LCDs3,9,14-17,232-234 * Double Cell Nematic Dichroic LCD3,8,9,14,15,233 * Double Cell One Pitch Cholesteric LCD16,17 * Double Cell Phase Change Dichroic LCD214,232 * POSITIVE MODE DICHROIC LCDS3,8,9 * Positive Mode Heilmeier Cells3,8,9,43,77,78,235-238 * USING PLEOCHROIC DYES3,8,9,43,235-238 * USING NEGATIVE DICHROIC DYES3,8,9,63,77,78156 * DUAL FREQUENCY ADDRESSED DICHROIC DISPLAYS75,238 * Positive Mode Dichroic LCDs Using λ/4 Plate * Positive Mode Double Cell Dichroic LCD * Positive Mode Dichroic LCDs Using Special Electrode patterns7,8,239-241 * Positive Mode Phase Change Dichroic LCDs3,8,9,230,243-248 * Dichroic LCDs Using an Admixture of Pleochroic and Negative Dichroic Dyes78,118 * SUPERTWIST DICHROIC EFFECT (SDE) DISPLAYS21-23 * FERROELECTRIC DICHROIC LCDs24-27 * Devices Using A Single Polarizer * Devices Using No Polarizer24-27 * POLYMER DISPERSED DICHROIC LCDs28-30,252-259 * DICHROIC POLYMER LIQUID CRYSTAL DISPLAYS * Heilmeier Type Displays * Guest-Host Cell Using an Admixture Of L.C. Polymer and Low Molecular Weight Liquid Crysta As Host * Polymeric Ferroelectric Dichroic LCDs * SMECTIC A DICHROIC LCDs * Laser

  4. CLOSEOUT REPORT FOR HYBRID SULFUR PRESSURIZED BUTTON CELL TEST FACILITY

    SciTech Connect

    Steeper, T.

    2010-09-15

    This document is the Close-Out Report for design and partial fabrication of the Pressurized Button Cell Test Facility at Savannah River National Laboratory (SRNL). This facility was planned to help develop the sulfur dioxide depolarized electrolyzer (SDE) that is a key component of the Hybrid Sulfur Cycle for generating hydrogen. The purpose of this report is to provide as much information as possible in case the decision is made to resume research. This report satisfies DOE Milestone M3GSR10VH030107.0. The HyS Cycle is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by watersplitting. The HyS Cycle utilizes the high temperature (>800 C) thermal decomposition of sulfuric acid to produce oxygen and regenerate sulfur dioxide. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Low cell voltage is essential for both high thermodynamic efficiency and low hydrogen cost. Sulfur dioxide is oxidized at the anode, producing sulfuric acid that is sent to the high temperature acid decomposition portion of the cycle. Sulfur dioxide from the decomposer is cycled back to electrolyzers. The electrolyzer cell uses the membrane electrode assembly (MEA) concept. Anode and cathode are formed by spraying a catalyst, typically platinized carbon, on both sides of a Proton Exchange Membrane (PEM). SRNL has been testing SDEs for several years including an atmospheric pressure Button Cell electrolyzer (2 cm{sup 2} active area) and an elevated temperature/pressure Single Cell electrolyzer (54.8 cm{sup 2} active area). SRNL tested 37 MEAs in the Single Cell electrolyzer facility from June 2005 until June 2009, when funding was discontinued. An important result of the final months of testing was the development of a method that