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Sample records for improve symbiotic system

  1. Symbiotic systems: observations and theory

    NASA Astrophysics Data System (ADS)

    Luna, Gerardo

    2016-07-01

    Although there is wide concensus about the binary nature of symbiotic stars, the nature of their central engine, the structure of the accretion flow and the accretion rate are poorly known. Modern observatories are now providing, for the first time, direct information about the central source of power and how it is fueled. The detection of hard (E > 20 keV) X-ray emission from a handful of symbiotics indicates that some symbiotics accrete at a low enough rate for a ˜10^{8} K accretion-disk boundary layer to remain optically thin and generate hard X-rays. Such high temperature is possible if the white dwarf is massive; symbiotics could thus be SNIa progenitors, the pilars of the current cosmological paradigm.

  2. Physiological limitations and the genetic improvement of symbiotic nitrogen fixation

    SciTech Connect

    Gara, F.O.; Manian, S. ); Drevon, J.J. )

    1988-01-01

    The rhizobium legume symbiosis continues to be of strategic importance particularly in the context of food production. As the world population grows, it is necessary that new developments take place in crop improvement. The development and application of new technologies in biological sciences over past years has made the entire area of plant-microbial interaction an exciting and challenging research area to be involved in. In view of the importance of symbiotic nitrogen fixation, it is not surprising that it still represents one of the priority areas for commercial development in agricultural biotechnology. Since this symbiosis involves an association between procaryotic and eucaryhotic partners, it requires of necessity a coordinated and interdisciplinary approach. This book focuses on physiological limitations affecting symbiotic nitrogen fixation and the potential for overcoming such limitations by using genetic technologies.

  3. Dynamic task allocation for a man-machine symbiotic system

    NASA Technical Reports Server (NTRS)

    Parker, L. E.; Pin, F. G.

    1987-01-01

    This report presents a methodological approach to the dynamic allocation of tasks in a man-machine symbiotic system in the context of dexterous manipulation and teleoperation. This report addresses a symbiotic system containing two symbiotic partners which work toward controlling a single manipulator arm for the execution of a series of sequential manipulation tasks. It is proposed that an automated task allocator use knowledge about the constraints/criteria of the problem, the available resources, the tasks to be performed, and the environment to dynamically allocate task recommendations for the man and the machine. The presentation of the methodology includes discussions concerning the interaction of the knowledge areas, the flow of control, the necessary communication links, and the replanning of the task allocation. Examples of task allocation are presented to illustrate the results of this methodolgy.

  4. The Symbiotic System SS73 17 seen with Suzaku

    NASA Technical Reports Server (NTRS)

    Smith, Randall K.; Mushotzky, Richard; Kallman, Tim; Tueller, Jack; Mukai, Koji; Markwardt, Craig

    2007-01-01

    We observed with Suzaku the symbiotic star SS73 17, motivated by the discovery by the INTEGRAL satellite and the Swift BAT survey that it emits hard X-rays. Our observations showed a highly-absorbed X-ray spectrum with NH > loz3 emp2, equivalent to Av > 26, although the source has B magnitude 11.3 and is also bright in UV. The source also shows strong, narrow iron lines including fluorescent Fe K as well as Fe xxv and Fe XXVI. The X-ray spectrum can be fit with a thermal model including an absorption component that partially covers the source. Most of the equivalent width of the iron fluorescent line in this model can be explained as a combination of reprocessing in a dense absorber plus reflection off a white dwarf surface, but it is likely that the continuum is partially seen in reflection as well. Unlike other symbiotic systems that show hard X-ray emission (CH Cyg, RT Cru, T CrB, GX1+4), SS73 17 is not known to have shown nova-like optical variability, X-ray flashes, or pulsations, and has always shown faint soft X-ray emission. As a result, although it is likely a white dwarf, the nature of the compact object in SS73 17 is still uncertain. SS73 17 is probably an extreme example of the recently discovered and relatively small class of hard X-ray emitting symbiotic systems.

  5. Role of time in symbiotic systems

    SciTech Connect

    Agrawala, A.K.

    1996-12-31

    All systems have a dynamics which reflects the changes in the system in time and, therefore, have to maintain a notion of time, either explicitly or implicitly. Traditionally, the notion of time in constructed systems has been implicitly specified at design time through rigid structures such as sampled data systems which operate with a fixed time tick, feedback systems which are designed reflecting a fixed time scale for the dynamics of the system as well as the controller responses, etc. In biological systems, the sense of time is a key element but it is not rigidly structured, even though all such systems have a clear notion of time. We define the notion of time in systems in terms of temporal locality, time scale and time horizon. Temporal locality gives the notion of the accuracy with which the system knows about the current time. Time scale reflects the scale indicating the smallest and the largest granularity considered. It also reflects the reaction time. The time horizon indicates the time beyond which the system considers to be distant future and may not take it into account in its actions. Note that the temporal locality, time scale and the time horizon may be different for different types of actions of a system, thereby permitting the system to use multiple notions of time concurrently. In multi agent systems each subsystem may have its own notion of time but when intentions take place a coordination is necessary. Such coordination requires that the notions of time for different agents of the system be consistent. Clearly, the consistency requirement in this case does not mean exactly identical but implies that different agents can coordinate their actions which must take place in time. When the actions only require a determinate ordering the required coordination is much less severe than the case requiring actions to take place at the same time.

  6. Infrared Spectroscopy of Symbiotic Stars. I. Orbits for Well-Known S-Type Systems

    NASA Astrophysics Data System (ADS)

    Fekel, Francis C.; Joyce, Richard R.; Hinkle, Kenneth H.; Skrutskie, Michael F.

    2000-03-01

    First results are reported for a program of monitoring symbiotic-star velocities in the 1.6 μm region with infrared-array technology. Infrared radial velocities have been used to determine single-lined spectroscopic orbits for six well-known symbiotic stars, EG And, T CrB, CI Cyg, BX Mon, RS Oph, and AG Peg. The new orbits are in general agreement with previous orbits derived from optical velocities. From the combined optical and infrared velocities improved orbital elements for the six systems have been determined. Each of the orbital periods has been determined solely from the radial-velocity data. With the addition of our new velocities, the orbital period of BX Mon has been revised to 1259 days, a 10% decrease from the previously reported result.

  7. Multi Groups Cooperation based Symbiotic Evolution for TSK-type Neuro-Fuzzy Systems Design

    PubMed Central

    Cheng, Yi-Chang; Hsu, Yung-Chi

    2010-01-01

    In this paper, a TSK-type neuro-fuzzy system with multi groups cooperation based symbiotic evolution method (TNFS-MGCSE) is proposed. The TNFS-MGCSE is developed from symbiotic evolution. The symbiotic evolution is different from traditional GAs (genetic algorithms) that each chromosome in symbiotic evolution represents a rule of fuzzy model. The MGCSE is different from the traditional symbiotic evolution; with a population in MGCSE is divided to several groups. Each group formed by a set of chromosomes represents a fuzzy rule and cooperate with other groups to generate the better chromosomes by using the proposed cooperation based crossover strategy (CCS). In this paper, the proposed TNFS-MGCSE is used to evaluate by numerical examples (Mackey-Glass chaotic time series and sunspot number forecasting). The performance of the TNFS-MGCSE achieves excellently with other existing models in the simulations. PMID:21709856

  8. Multi Groups Cooperation based Symbiotic Evolution for TSK-type Neuro-Fuzzy Systems Design.

    PubMed

    Cheng, Yi-Chang; Hsu, Yung-Chi; Lin, Sheng-Fuu

    2010-07-01

    In this paper, a TSK-type neuro-fuzzy system with multi groups cooperation based symbiotic evolution method (TNFS-MGCSE) is proposed. The TNFS-MGCSE is developed from symbiotic evolution. The symbiotic evolution is different from traditional GAs (genetic algorithms) that each chromosome in symbiotic evolution represents a rule of fuzzy model. The MGCSE is different from the traditional symbiotic evolution; with a population in MGCSE is divided to several groups. Each group formed by a set of chromosomes represents a fuzzy rule and cooperate with other groups to generate the better chromosomes by using the proposed cooperation based crossover strategy (CCS). In this paper, the proposed TNFS-MGCSE is used to evaluate by numerical examples (Mackey-Glass chaotic time series and sunspot number forecasting). The performance of the TNFS-MGCSE achieves excellently with other existing models in the simulations. PMID:21709856

  9. [Full-scale experiments of municipal sewage treated by symbiotic system consisting of tubifex and microbes].

    PubMed

    Lou, Ju-qing; Guo, Mao-xin; Sun, Pei-de; Wu, Ge; Song, Ying-qi

    2009-12-01

    A symbiotic system consisting of tubifex and microbe was formed when tubifex was incubated in the biological contact oxidation process,the tubifex attached to the outer layer of the carriers. When the density of tubifex was about 31.3 g/L, a recycling food chain between corpse of tubifex and excrement and wastewater and microbe and sludge was formed and it could reach balance. The large scale control experimental system for treating 20,000 m3 x d(-1) municipal sewage was carried out for a long time. The result showed that tubifex could improve water quality in the effluent. When the concentration in the influent of COD,NH4+ -N,TP and SS were 130-459, 14.21-27.46, 1.60-6.93, 60-466 mg x L(-1), respectively,the removal rates of COD and SS can be improved by 8.7% and 13.6%. However, tubifex can also increase the concentration of NH4+ -N in the system,but a proper operation can make the effluent concentration of NH4+ -N below 5 mg x L(-1) stably. The symbiotic system consisting of tubifex and microbe has very good phosphorus removal efficiency. The reactor has a high toleration to loading shock and it could keep the effluent quality stable. PMID:20187394

  10. Evolution of the symbiotic binary system AG Dranconis

    NASA Technical Reports Server (NTRS)

    Mikolajewska, Joanna; Kenyon, Scott J; Mikolajewski, Maciej; Garcia, Michael R.; Polidan, Ronald S.

    1995-01-01

    We present an analysis of new and archival photometric and spectroscopic observations of the symbiotic star AG Draconis. This binary has undergone several 1 - 3 mag optical and ultraviolet eruptions during the past 15 years. Our combination of optical and ultraviolet spectroscopic data allow a more complete analysis of this system than in previous papers. AG Dra is composed of a K-type bright giant M(sub g) approximately 1.5 solar mass) and a hot, compact star M(sub h approximatelly 0.4 - 0.6 solar mass) embedded in a dense, low metallicity nebula. The hot component undergoes occasional thermonuclear runaways that produce 2 - 3 mag optical/ultraviolet eruptions. During these eruptions, the hot component develops a low velocity wind that quenches x-ray emission from the underlying hot white dwarf. The photoionized nebula changes its volume by a factor of 5 throughout an eruptin cycle. The K bright giant occults low ionization emission lines during superior conjunctions at all outburst phases but does not occult high ionization lines in outburst (and perhaps quiescence). This geometry and the component masses suggest a system inclination of i approximately 30 deg - 45 deg.

  11. THE THERAPEUTIC USE OF SYMBIOTICS

    PubMed Central

    FLESCH, Aline Gamarra Taborda; POZIOMYCK, Aline Kirjner; DAMIN, Daniel De Carvalho

    2014-01-01

    Introduction Functional foods are health promoters and their use is associated with reduced risk of chronic degenerative and non-transmissible diseases. Examples are symbiotic. The association of one (or more) probiotic with a one (or more) prebiotic is called symbiotic, being the prebiotics complementary and probiotics synergistic, thus presenting a multiplicative factor on their individual actions. Objective To assess the evidences on the benefits of the use of symbiotics in the treatment of clinical and surgical situations. Methods The headings symbiotic, probiotic and prebiotic were searched in Pubmed/Medline in the last 15 years, and were selected 25 articles, used for database. Results The use of symbiotic may promote an increase in the number of bifidobacteria, glycemic control, reduction of blood cholesterol, balancing the intestinal flora which aids in reducing constipation and/or diarrhea, improves intestinal permeability and stimulation of the immune system. Clinical indications for these products has been expanded, in order to maximize the individual's physiological functions to provide greater. So, with the high interest in the clinical and nutritional control of disease, many studies have been conducted demonstrating the effectiveness of using symbiotic in improving and/or preventing various and/or symptoms of gastrointestinal diseases. Conclusion Symbiotic behave differently and positively in various pathological situations. PMID:25184774

  12. Symbiotic Expressions

    NASA Astrophysics Data System (ADS)

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

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

  13. Job planning and execution monitoring for a human-robot symbiotic system

    SciTech Connect

    Parker, L.E.

    1989-11-01

    The human-robot symbiosis concept has the fundamental objective of bridging the gap between fully human-controlled and fully autonomous systems to achieve true human-robot cooperative control and intelligence. Such a system would allow improved speed, accuracy, and efficiency of task execution, while retaining the human in the loop for innovative reasoning and decision-making. Earlier research has resulted in the development of a robotic system architecture facilitating the symbiotic integration of teleoperative and automated modes of task execution. This architecture reflects a unique blend of many disciplines of artificial intelligence into a working system, including job or mission planning, dynamic task allocation, human-robot communication, automated monitoring, and machine learning. This report focuses on two elements of this architecture: the Job Planner and the Automated Monitor. 17 refs., 7 figs.

  14. Symbiotic stars

    NASA Technical Reports Server (NTRS)

    Kafatos, M.; Michalitsianos, A. G.

    1984-01-01

    The physical characteristics of symbiotic star systems are discussed, based on a review of recent observational data. A model of a symbiotic star system is presented which illustrates how a cool red-giant star is embedded in a nebula whose atoms are ionized by the energetic radiation from its hot compact companion. UV outbursts from symbiotic systems are explained by two principal models: an accretion-disk-outburst model which describes how material expelled from the tenuous envelope of the red giant forms an inwardly-spiralling disk around the hot companion, and a thermonuclear-outburst model in which the companion is specifically a white dwarf which superheats the material expelled from the red giant to the point where thermonuclear reactions occur and radiation is emitted. It is suspected that the evolutionary course of binary systems is predetermined by the initial mass and angular momentum of the gas cloud within which binary stars are born. Since red giants and Mira variables are thought to be stars with a mass of one or two solar mass, it is believed that the original cloud from which a symbiotic system is formed can consist of no more than a few solar masses of gas.

  15. Colliding Winds in Symbiotic Binary Systems. II. Colliding Winds Geometries and Orbital Motion in the Symbiotic Nova AG Pegasi

    NASA Astrophysics Data System (ADS)

    Kenny, H. T.; Taylor, A. R.

    2007-06-01

    AG Pegasi has been observed at high angular resolution and sensitivity at the Very Large Array (VLA) at 5 GHz in four epochs between 1984 and 1991. Analysis of the radio visibilities indicate that a mass of 4.0+/-0.5×10-5 Msolar is concentrated in the inner nebula and is moving outward at a velocity of 53+/-4 km s-1 (D=600 pc assumed). In order to explain the observed morphology of the inner nebula, a new colliding winds model is derived, which includes the effects of orbital motion (CWo model). Orbital effects cannot be ignored in AG Pegasi since the orbital timescale (2.25 yr; Meinunger 1981) is short compared to the likely timescale of wind collision (symbiotic nova eruption beginning ~1850 Merrill 1959). When these effects are considered, the interaction front between binary stellar winds is wrapped into spiral walls whose density decreases outward with 1/r2. Distinctive geometries are found to arise depending on which wind dominates the interaction, the late-type wind from the symbiotic ``cool component,'' or the high-velocity wind from the ``hot component.'' Application of the CWo model to AG Peg suggests that the observed transient lobe enhancements of the inner nebula arise due to changes in the mass-loss rate from the hot component. Hot component mass-loss rates ranging between 2.1 and 6.0×10-8 Msolar yr-1 are derived. The model is also successful in reproducing the radio spectrum of the central unresolved object of the system. A position angle of -15deg+/-10deg is inferred for the orbital pole as projected on the plane of the sky.

  16. On the effect of ionization on the circumbinary material in symbiotic systems

    NASA Astrophysics Data System (ADS)

    Shagatova, N.

    2015-12-01

    A double nature of the circumbinary matter in symbiotic systems, i. e. the presence of H0 and H+ regions, offers an opportunity to investigate both the properties of the wind from the donor star and the effect of radiation from the ionizing companion onto the surrounding material. In this contribution we explain the importance of the effect of ionization for a proper treating of the inversion problem for the wind velocity profile. The method allows us to obtain the models for total and neutral hydrogen column densities and corresponding wind velocity profiles. We describe in detail the process of modelling for the spherically symmetric wind and compare it with simpler approaches. The first application of our improved approach revealed that the effect of ionization on the column density shapes is not negligible for a wide range of orbital phases, in contrast to the assumptions in previous papers. Thus, it implies a higher concentration of the wind matter than it was supposed before.

  17. Chemical abundance analysis of symbiotic giants - III. Metallicity and CNO abundance patterns in 24 southern systems

    NASA Astrophysics Data System (ADS)

    Gałan, Cezary; Mikołajewska, Joanna; Hinkle, Kenneth H.; Joyce, Richard R.

    2016-01-01

    The elemental abundances of symbiotic giants are essential to address the role of chemical composition in the evolution of symbiotic binaries, to map their parent population, and to trace their mass transfer history. However, the number of symbiotic giants with fairly well determined photospheric composition is still insufficient for statistical analyses. This is the third in a series of papers on the chemical composition of symbiotic giants determined from high-resolution (R ˜ 50 000), near-infrared spectra. Here we present results for 24 S-type systems. Spectrum synthesis methods employing standard local thermal equilibrium analysis and atmosphere models were used to obtain photospheric abundances of CNO and elements around the iron peak (Fe, Ti, Ni, and Sc). Our analysis reveals metallicities distributed in a wide range from slightly supersolar ([Fe/H] ˜ +0.35 dex) to significantly subsolar ([Fe/H] ˜ -0.8 dex) but principally with near-solar and slightly subsolar metallicity ([Fe/H] ˜ -0.4 to -0.3 dex). The enrichment in 14N isotope, found in all these objects, indicates that the giants have experienced the first dredge-up. This was confirmed in a number of objects by the low 12C/13C ratio (5-23). We found that the relative abundance of [Ti/Fe] is generally large in red symbiotic systems.

  18. Symbiotic Stars

    NASA Astrophysics Data System (ADS)

    Munari, U.

    2012-06-01

    Symbiotic stars are interacting binary systems composed of a white dwarf (WD) accreting at high rate from a cool giant companion, which frequently fills its Roche lobe. The WD usually is extremely hot and luminous, and able to ionize a sizeable fraction of the cool giant wind, because it is believed the WD undergoes stable hydrogen nuclear burning on its surface of the material accreted from the companion. This leads to consider symbiotic stars as good candidates for the yet-to-be-identified progenitors of type Ia supernovae. Symbiotic stars display the simultaneous presence of many different types of variability, induced by the cool giant, the accreting WD, the circumstellar dust and ionized gas, with time scales ranging from seconds to decades. The long orbital periods (typically a couple of years) and complex outburst patterns, lasting from a few years to a century, make observations from professionals almost impossible to carry out, and open great opportunities to amateur astronomers to contribute fundamental data to science.

  19. Population genetic data of a model symbiotic cnidarian system reveal remarkable symbiotic specificity and vectored introductions across ocean basins.

    PubMed

    Thornhill, Daniel J; Xiang, Yu; Pettay, D Tye; Zhong, Min; Santos, Scott R

    2013-09-01

    The Aiptasia-Symbiodinium symbiosis is a promising model for experimental studies of cnidarian-dinoflagellate associations, yet relatively little is known regarding the genetic diversity of either symbiotic partner. To address this, we collected Aiptasia from 16 localities throughout the world and examined the genetic diversity of both anemones and their endosymbionts. Based on newly developed SCAR markers, Aiptasia consisted of two genetically distinct populations: one Aiptasia lineage from Florida and a second network of Aiptasia genotypes found at other localities. These populations did not conform to the distributions of described Aiptasia species, suggesting that taxonomic re-evaluation is needed in the light of molecular genetics. Associations with Symbiodinium further demonstrated the distinctions among Aiptasia populations. According to 18S RFLP, ITS2-DGGE and microsatellite flanker region sequencing, Florida anemones engaged in diverse symbioses predominantly with members of Symbiodinium Clades A and B, but also C, whereas anemones from elsewhere harboured only S. minutum within Clade B. Symbiodinium minutum apparently does not form a stable symbiosis with other hosts, which implies a highly specific symbiosis. Fine-scale differences among S. minutum populations were quantified using six microsatellite loci. Populations of S. minutum had low genotypic diversity and high clonality (R = 0.14). Furthermore, minimal population structure was observed among regions and ocean basins, due to allele and genotype sharing. The lack of genetic structure and low genotypic diversity suggest recent vectoring of Aiptasia and S. minutum across localities. This first ever molecular-genetic study of a globally distributed cnidarian and its Symbiodinium assemblages reveals host-symbiont specificity and widely distributed populations in an important model system. PMID:23980764

  20. A PRECESSING JET IN THE CH Cyg SYMBIOTIC SYSTEM

    SciTech Connect

    Karovska, Margarita; Gaetz, Terrance J.; Raymond, John C.; Lee, Nicholas P.; Carilli, Christopher L.; Hack, Warren

    2010-02-20

    Jets have been detected in only a few symbiotic binaries to date, and CH Cyg is one of them. In 2001, a non-relativistic jet was detected in CH Cyg for the first time in X-rays. We carried out coordinated Chandra, Hubble Space Telescope (HST), and VLA observations in 2008 to study the propagation of this jet and its interaction with the circumbinary medium. We detected the jet with Chandra and HST and determined that the apex has expanded to the south from {approx}300 AU to {approx}1400 AU, with the shock front propagating with velocity <100 km s{sup -1}. The shock front has significantly slowed down since 2001. Unexpectedly, we also discovered a powerful jet in the NE-SW direction, in the X-ray, optical and radio. This jet has a multi-component structure, including an inner jet and a counterjet at {approx}170 AU, and a SW component ending in several clumps extending out to {approx}750 AU. The structure of the jet and the curvature of the outer portion of the SW jet suggest an episodically powered precessing jet or a continuous precessing jet with occasional mass ejections or pulses. We carried out detailed spatial mapping of the X-ray emission and correlation with the optical and radio emission. X-ray spectra were extracted from the central source, inner NE counterjet, and the brightest clump at a distance of {approx}500 AU from the central source. We discuss the initial results of our analyses, including the multi-component spectral fitting of the jet components and of the central source.

  1. A study of the mass loss rates of symbiotic star systems

    NASA Astrophysics Data System (ADS)

    Korreck, K. E.; Kellogg, E.; Sokoloski, J. L.

    2007-08-01

    The amount of mass loss in symbiotic systems is investigated, specifically mass loss via the formation of jets in R Aquarii (R Aqr). The jets in R Aqr have been observed in the X-ray by Chandra over a four year time period. The jet changes on times scales of a year and new outflows have been observed. Understanding the amount of mass and the frequency of ejection further constrain the ability of the white dwarf in the system to accrete enough mass to become a Type 1a supernova progenitor. The details of multi-wavelength studies, such as speed, density and spatial extent of the jets will be discussed in order to understand the mass balance in the binary system. We examine other symbiotic systems to determine trends in mass loss in this class of objects.

  2. A Study of the Mass Loss Rates of Symbiotic Star Systems

    NASA Technical Reports Server (NTRS)

    Korreck, K. E.; Kellogg, E.; Sokoloski, J. L.

    2007-01-01

    The amount of mass loss in symbiotic systems is investigated, specifically mass loss via the formation of jets in R Aquarii (R Aqr). The jets in R Aqr have been observed in the X-ray by Chandra over a four year time period. The jet changes on times scales of a year and new outflows have been observed. Understanding the amount of mass and the frequency of ejection further constrain the ability of the white dwarf in the system to accrete enough mass to become a Type la supernova progenitor. The details of multi-wavelength studies, such as speed, density and spatial extent of the jets will be discussed in order to understand the mass balance in the binary system. We examine other symbiotic systems to determine trends in mass loss in this class of objects.

  3. Social network analysis and network connectedness analysis for industrial symbiotic systems: model development and case study

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Zheng, Hongmei; Chen, Bin; Yang, Naijin

    2013-06-01

    An important and practical pattern of industrial symbiosis is rapidly developing: eco-industrial parks. In this study, we used social network analysis to study the network connectedness (i.e., the proportion of the theoretical number of connections that had been achieved) and related attributes of these hybrid ecological and industrial symbiotic systems. This approach provided insights into details of the network's interior and analyzed the overall degree of connectedness and the relationships among the nodes within the network. We then characterized the structural attributes of the network and subnetwork nodes at two levels (core and periphery), thereby providing insights into the operational problems within each eco-industrial park. We chose ten typical ecoindustrial parks in China and around the world and compared the degree of network connectedness of these systems that resulted from exchanges of products, byproducts, and wastes. By analyzing the density and nodal degree, we determined the relative power and status of the nodes in these networks, as well as other structural attributes such as the core-periphery structure and the degree of sub-network connectedness. The results reveal the operational problems created by the structure of the industrial networks and provide a basis for improving the degree of completeness, thereby increasing their potential for sustainable development and enriching the methods available for the study of industrial symbiosis.

  4. IGR J17463-2854, a possible symbiotic binary system in the galactic center region

    NASA Astrophysics Data System (ADS)

    Karasev, D. I.; Tsygankov, S. S.; Lutovinov, A. A.

    2015-08-01

    This paper is devoted to determining the nature of the hard X-ray source IGR J17463-2854 located toward the Galactic bulge. Using data from the INTEGRAL and Chandra X-ray observatories, we show that five point X-ray sources with approximately identical fluxes in the 2-10 keV energy band are detected in the error circle of the object under study. In addition, significant absorption at low energies has been detected in the spectra of all these sources. Based on data from the VVV (VISTA/ESO) infrared Galactic Bulge Survey, we have unambiguously identified three of the five sources, determined the J, H, and K magnitudes of the corresponding stars, and obtained upper limits on the fluxes for the remaining two sources. Analysis of the color-magnitude diagrams has shown that one of these objects most likely belongs to a class of rarely encountered objects, symbiotic binary systems (several tens are known with certainty), i.e., low-mass binary systems consisting of a white dwarf and a red giant. It is important to note that all our results were obtained using improved absorption values and an extinction law differing in this direction from the standard one.

  5. Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems

    SciTech Connect

    D. E. Shropshire

    2009-01-01

    The Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems, prepared to support the U.S. Advanced Fuel Cycle Initiative (AFCI) systems analysis, provides a technology-oriented baseline system cost comparison between the open fuel cycle and closed fuel cycle systems. The intent is to understand their overall cost trends, cost sensitivities, and trade-offs. This analysis also improves the AFCI Program’s understanding of the cost drivers that will determine nuclear power’s cost competitiveness vis-a-vis other baseload generation systems. The common reactor-related costs consist of capital, operating, and decontamination and decommissioning costs. Fuel cycle costs include front-end (pre-irradiation) and back-end (post-iradiation) costs, as well as costs specifically associated with fuel recycling. This analysis reveals that there are large cost uncertainties associated with all the fuel cycle strategies, and that overall systems (reactor plus fuel cycle) using a closed fuel cycle are about 10% more expensive in terms of electricity generation cost than open cycle systems. The study concludes that further U.S. and joint international-based design studies are needed to reduce the cost uncertainties with respect to fast reactor, fuel separation and fabrication, and waste disposition. The results of this work can help provide insight to the cost-related factors and conditions needed to keep nuclear energy (including closed fuel cycles) economically competitive in the U.S. and worldwide. These results may be updated over time based on new cost information, revised assumptions, and feedback received from additional reviews.

  6. Improved Phytophthora resistance in commercial chickpea (Cicer arietinum) varieties negatively impacts symbiotic gene signalling and symbiotic potential in some varieties.

    PubMed

    Plett, Jonathan M; Plett, Krista L; Bithell, Sean L; Mitchell, Chris; Moore, Kevin; Powell, Jeff R; Anderson, Ian C

    2016-08-01

    Breeding disease-resistant varieties is one of the most effective and economical means to combat soilborne diseases in pulse crops. Commonalities between pathogenic and mutualistic microbe colonization strategies, however, raises the concern that reduced susceptibility to pathogens may simultaneously reduce colonization by beneficial microbes. We investigate here the degree of overlap in the transcriptional response of the Phytophthora medicaginis susceptible chickpea variety 'Sonali' to the early colonization stages of either Phytophthora, rhizobial bacteria or arbuscular mycorrhizal fungi. From a total of 6476 genes differentially expressed in Sonali roots during colonization by any of the microbes tested, 10.2% were regulated in a similar manner regardless of whether it was the pathogenic oomycete or a mutualistic microbe colonizing the roots. Of these genes, 49.7% were oppositely regulated under the same conditions in the moderately Phytophthora resistant chickpea variety 'PBA HatTrick'. Chickpea varieties with improved resistance to Phytophthora also displayed lower colonization by rhizobial bacteria and mycorrhizal fungi leading to an increased reliance on N and P from soil. Together, our results suggest that marker-based breeding in crops such as chickpea should be further investigated such that plant disease resistance can be tailored to a specific pathogen without affecting mutualistic plant:microbe interactions. PMID:27103212

  7. Models of symbiotic stars

    NASA Technical Reports Server (NTRS)

    Friedjung, Michael

    1993-01-01

    One of the most important features of symbiotic stars is the coexistence of a cool spectral component that is apparently very similar to the spectrum of a cool giant, with at least one hot continuum, and emission lines from very different stages of ionization. The cool component dominates the infrared spectrum of S-type symbiotics; it tends to be veiled in this wavelength range by what appears to be excess emission in D-type symbiotics, this excess usually being attributed to circumstellar dust. The hot continuum (or continua) dominates the ultraviolet. X-rays have sometimes also been observed. Another important feature of symbiotic stars that needs to be explained is the variability. Different forms occur, some variability being periodic. This type of variability can, in a few cases, strongly suggest the presence of eclipses of a binary system. One of the most characteristic forms of variability is that characterizing the active phases. This basic form of variation is traditionally associated in the optical with the veiling of the cool spectrum and the disappearance of high-ionization emission lines, the latter progressively appearing (in classical cases, reappearing) later. Such spectral changes recall those of novae, but spectroscopic signatures of the high-ejection velocities observed for novae are not usually detected in symbiotic stars. However, the light curves of the 'symbiotic nova' subclass recall those of novae. We may also mention in this connection that radio observations (or, in a few cases, optical observations) of nebulae indicate ejection from symbiotic stars, with deviations from spherical symmetry. We shall give a historical overview of the proposed models for symbiotic stars and make a critical analysis in the light of the observations of symbiotic stars. We describe the empirical approach to models and use the observational data to diagnose the physical conditions in the symbiotics stars. Finally, we compare the results of this empirical

  8. The Symbiotic Performance of Chickpea Rhizobia Can Be Improved by Additional Copies of the clpB Chaperone Gene.

    PubMed

    Paço, Ana; Brígido, Clarisse; Alexandre, Ana; Mateos, Pedro F; Oliveira, Solange

    2016-01-01

    The ClpB chaperone is known to be involved in bacterial stress response. Moreover, recent studies suggest that this protein has also a role in the chickpea-rhizobia symbiosis. In order to improve both stress tolerance and symbiotic performance of a chickpea microsymbiont, the Mesorhizobium mediterraneum UPM-Ca36T strain was genetically transformed with pPHU231 containing an extra-copy of the clpB gene. To investigate if the clpB-transformed strain displays an improved stress tolerance, bacterial growth was evaluated under heat and acid stress conditions. In addition, the effect of the extra-copies of the clpB gene in the symbiotic performance was evaluated using plant growth assays (hydroponic and pot trials). The clpB-transformed strain is more tolerant to heat shock than the strain transformed with pPHU231, supporting the involvement of ClpB in rhizobia heat shock tolerance. Both plant growth assays showed that ClpB has an important role in chickpea-rhizobia symbiosis. The nodulation kinetics analysis showed a higher rate of nodule appearance with the clpB-transformed strain. This strain also induced a greater number of nodules and, more notably, its symbiotic effectiveness increased ~60% at pH5 and 83% at pH7, compared to the wild-type strain. Furthermore, a higher frequency of root hair curling was also observed in plants inoculated with the clpB-transformed strain, compared to the wild-type strain. The superior root hair curling induction, nodulation ability and symbiotic effectiveness of the clpB-transformed strain may be explained by an increased expression of symbiosis genes. Indeed, higher transcript levels of the nodulation genes nodA and nodC (~3 folds) were detected in the clpB-transformed strain. The improvement of rhizobia by addition of extra-copies of the clpB gene may be a promising strategy to obtain strains with enhanced stress tolerance and symbiotic effectiveness, thus contributing to their success as crop inoculants, particularly under

  9. Local and Systemic Regulation of Plant Root System Architecture and Symbiotic Nodulation by a Receptor-Like Kinase

    PubMed Central

    Huault, Emeline; Laffont, Carole; Wen, Jiangqi; Mysore, Kirankumar S.; Ratet, Pascal; Duc, Gérard; Frugier, Florian

    2014-01-01

    In plants, root system architecture is determined by the activity of root apical meristems, which control the root growth rate, and by the formation of lateral roots. In legumes, an additional root lateral organ can develop: the symbiotic nitrogen-fixing nodule. We identified in Medicago truncatula ten allelic mutants showing a compact root architecture phenotype (cra2) independent of any major shoot phenotype, and that consisted of shorter roots, an increased number of lateral roots, and a reduced number of nodules. The CRA2 gene encodes a Leucine-Rich Repeat Receptor-Like Kinase (LRR-RLK) that primarily negatively regulates lateral root formation and positively regulates symbiotic nodulation. Grafting experiments revealed that CRA2 acts through different pathways to regulate these lateral organs originating from the roots, locally controlling the lateral root development and nodule formation systemically from the shoots. The CRA2 LRR-RLK therefore integrates short- and long-distance regulations to control root system architecture under non-symbiotic and symbiotic conditions. PMID:25521478

  10. Application of plant genomics for improved symbiotic nitrogen fixation in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because genome sequencing, transcript profiling, proteome analysis, metabolite profiling, mutant analysis, and comparative genomics have progressed at a logarithmic pace, we know more about the plant genes involved in symbiotic nitrogen fixation (SNF) than could have been imagined a decade ago. Howe...

  11. An Analysis on a Negotiation Model Based on Multiagent Systems with Symbiotic Learning and Evolution

    NASA Astrophysics Data System (ADS)

    Hossain, Md. Tofazzal

    This study explores an evolutionary analysis on a negotiation model based on Masbiole (Multiagent Systems with Symbiotic Learning and Evolution) which has been proposed as a new methodology of Multiagent Systems (MAS) based on symbiosis in the ecosystem. In Masbiole, agents evolve in consideration of not only their own benefits and losses, but also the benefits and losses of opponent agents. To aid effective application of Masbiole, we develop a competitive negotiation model where rigorous and advanced intelligent decision-making mechanisms are required for agents to achieve solutions. A Negotiation Protocol is devised aiming at developing a set of rules for agents' behavior during evolution. Simulations use a newly developed evolutionary computing technique, called Genetic Network Programming (GNP) which has the directed graph-type gene structure that can develop and design the required intelligent mechanisms for agents. In a typical scenario, competitive negotiation solutions are reached by concessions that are usually predetermined in the conventional MAS. In this model, however, not only concession is determined automatically by symbiotic evolution (making the system intelligent, automated, and efficient) but the solution also achieves Pareto optimal automatically.

  12. Changes in symbiotic and associative interrelations in a higher plant-bacterial system during space flight

    NASA Astrophysics Data System (ADS)

    Kordyum, V. A.; Man'ko, V. G.; Popova, A. F.; Shcherbak, O. H.; Mashinsky, A. L.; Nguen-Hgue-Thyok

    The miniature cenosis consisting of the water fern Azolla with its associated symbiotic nitrogen-fixing cyanobacterium Anabaena and the concomitant bacteria was investigated. Ecological closure was shown to produce sharp quantitative and qualitative changes in the number and type of concomitant bacteria. Changes in the distribution of bacterial types grown on beef-extract broth after space flight were recorded. Anabaena azollae underwent the most significant changes under spaceflight conditions. Its cell number per Azolla biomass unit increased substantially. Thus closure of cenosis resulted in a weakening of control over microbial development by Azolla. This tendency was augmented by spaceflight factors. Reduction in control exerted by macro-organisms over development of associated micro-organisms must be taken into account in constructing closed ecological systems in the state of weightlessness.

  13. Comparative metagenomic analysis of microcosm structures and lignocellulolytic enzyme systems of symbiotic biomass-degrading consortia.

    PubMed

    Wongwilaiwalin, Sarunyou; Laothanachareon, Thanaporn; Mhuantong, Wuttichai; Tangphatsornruang, Sithichoke; Eurwilaichitr, Lily; Igarashi, Yasuo; Champreda, Verawat

    2013-10-01

    Decomposition of lignocelluloses by cooperative microbial actions is an essential process of carbon cycling in nature and provides a basis for biomass conversion to fuels and chemicals in biorefineries. In this study, structurally stable symbiotic aero-tolerant lignocellulose-degrading microbial consortia were obtained from biodiversified microflora present in industrial sugarcane bagasse pile (BGC-1), cow rumen fluid (CRC-1), and pulp mill activated sludge (ASC-1) by successive subcultivation on rice straw under facultative anoxic conditions. Tagged 16S rRNA gene pyrosequencing revealed that all isolated consortia originated from highly diverse environmental microflora shared similar composite phylum profiles comprising mainly Firmicutes, reflecting convergent adaptation of microcosm structures, however, with substantial differences at refined genus level. BGC-1 comprising cellulolytic Clostridium and Acetanaerobacterium in stable coexistence with ligninolytic Ureibacillus showed the highest capability on degradation of agricultural residues and industrial pulp waste with CMCase, xylanase, and β-glucanase activities in the supernatant. Shotgun pyrosequencing of the BGC-1 metagenome indicated a markedly high relative abundance of genes encoding for glycosyl hydrolases, particularly for lignocellulytic enzymes in 26 families. The enzyme system comprised a unique composition of main-chain degrading and side-chain processing hydrolases, dominated by GH2, 3, 5, 9, 10, and 43, reflecting adaptation of enzyme profiles to the specific substrate. Gene mapping showed metabolic potential of BGC-1 for conversion of biomass sugars to various fermentation products of industrial importance. The symbiotic consortium is a promising simplified model for study of multispecies mechanisms on consolidated bioprocessing and a platform for discovering efficient synergistic enzyme systems for biotechnological application. PMID:23381385

  14. Gut Microbiota-Induced Immunoglobulin G Controls Systemic Infection by Symbiotic Bacteria and Pathogens.

    PubMed

    Zeng, Melody Y; Cisalpino, Daniel; Varadarajan, Saranyaraajan; Hellman, Judith; Warren, H Shaw; Cascalho, Marilia; Inohara, Naohiro; Núñez, Gabriel

    2016-03-15

    The gut microbiota is compartmentalized in the intestinal lumen and induces local immune responses, but it remains unknown whether the gut microbiota can induce systemic response and contribute to systemic immunity. We report that selective gut symbiotic gram-negative bacteria were able to disseminate systemically to induce immunoglobulin G (IgG) response, which primarily targeted gram-negative bacterial antigens and conferred protection against systemic infections by E. coli and Salmonella by directly coating bacteria to promote killing by phagocytes. T cells and Toll-like receptor 4 on B cells were important in the generation of microbiota-specific IgG. We identified murein lipoprotein (MLP), a highly conserved gram-negative outer membrane protein, as a major antigen that induced systemic IgG homeostatically in both mice and humans. Administration of anti-MLP IgG conferred crucial protection against systemic Salmonella infection. Thus, our findings reveal an important function for the gut microbiota in combating systemic infection through the induction of protective IgG. PMID:26944199

  15. Isolation and characterisation of non-anaerobic butanol-producing symbiotic system TSH06.

    PubMed

    Wang, Genyu; Wu, Pengfei; Liu, Ya; Mi, Shuo; Mai, Shuai; Gu, Chunkai; Wang, Gehua; Liu, Hongjuan; Zhang, Jianan; Børresen, Børre Tore; Mellemsæther, Evy; Kotlar, Hans Kristian

    2015-10-01

    Butanol-producing microorganisms are all obligate anaerobes. In this study, a unique symbiotic system TSH06 was isolated to be capable of producing butanol under non-anaerobic condition. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S ribosomal RNA (rRNA) revealed that two strains coexist in TSH06. The two strains were identical to Clostridium acetobutylicum and Bacillus cereus, respectively. They were isolated individually and named as C. acetobutylicum TSH1 and B. cereus TSH2. C. acetobutylicum TSH1 is a butanol-producing, obligate anaerobic strain. Facultative anaerobic B. cereus TSH2 did not possess the ability of butanol production; however, it offered C. acetobutylicum TSH1 the viability under non-anaerobic condition. Moreover, B. cereus TSH2 enhanced butanol yield and speed of fermentation. TSH06 produced 12.97 g/L butanol and 15.39 g/L total solvent under non-anaerobic condition, which is 25 and 24 %, respectively, higher than those of C. acetobutylicum TSH1. In addition, TSH06 produced butanol faster under non-anaerobic condition than under anaerobic condition. Butanol accounted for more than 80 % of total solvent, which is higher than the known report. TSH06 was stable during passage. In all, TSH06 is a promising candidate for industrialisation of biobutanol with high yield, high butanol proportion, easy-handling and time-saving system. These results demonstrated the potential advantage of symbiosis. This study also provides a promising strategy for butanol fermentation. PMID:26272091

  16. A phosphate transport system is required for symbiotic nitrogen fixation by Rhizobium meliloti.

    PubMed Central

    Bardin, S; Dan, S; Osteras, M; Finan, T M

    1996-01-01

    The bacterium Rhizobium meliloti forms N2-fixing root nodules on alfalfa plants. The ndvF locus, located on the 1,700-kb pEXO megaplasmid of R. meliloti, is required for nodule invasion and N2 fixation. Here we report that ndvF contains four genes, phoCDET, which encode an ABC-type transport system for the uptake of Pi into the bacteria. The PhoC and PhoD proteins are homologous to the Escherichia coli phosphonate transport proteins PhnC and PhnD. The PhoT and PhoE proteins are homologous to each other and to the E. coli phosphonate transport protein PhnE. We show that the R. meliloti phoD and phoE genes are induced in response to phosphate starvation and that the phoC promoter contains two elements which are similar in sequence to the PHO boxes present in E. coli phosphate-regulated promoters. The R. meliloti ndvF mutants grow poorly at a phosphate concentration of 2 mM, and we hypothesize that their symbiotic phenotype results from their failure to grow during the nodule infection process. Presumably, the PhoCDET transport system is employed by the bacteria in the soil environment, where the concentration of available phosphate is normally 0.1 to 1 microM. PMID:8755882

  17. The Type III Secretion System of Bradyrhizobium japonicum USDA122 Mediates Symbiotic Incompatibility with Rj2 Soybean Plants

    PubMed Central

    Tsukui, Takahiro; Eda, Shima; Kaneko, Takakazu; Sato, Shusei; Okazaki, Shin; Kakizaki-Chiba, Kaori; Itakura, Manabu; Mitsui, Hisayuki; Yamashita, Akifumi; Terasawa, Kimihiro

    2013-01-01

    The rhcJ and ttsI mutants of Bradyrhizobium japonicum USDA122 for the type III protein secretion system (T3SS) failed to secrete typical effector proteins and gained the ability to nodulate Rj2 soybean plants (Hardee), which are symbiotically incompatible with wild-type USDA122. This suggests that effectors secreted via the T3SS trigger incompatibility between these two partners. PMID:23204412

  18. Evolution of the symbiotic binary system AG Pegasi - The slowest classical nova eruption ever recorded

    NASA Technical Reports Server (NTRS)

    Kenyon, Scott J.; Mikolajewska, Joanna; Mikolajewski, Maciej; Polidan, Ronald S.; Slovak, Mark H.

    1993-01-01

    We present an analysis of new and existing photometric and spectroscopic observations of the ongoing eruption in the symbiotic star AG Pegasi, showing that this binary has evolved considerably since the turn of the century. Recent dramatic changes in both the UV continuum and the wind from the hot component allow a more detailed analysis than in previous papers. AG Peg is composed of a normal M3 giant and a hot, compact star embedded in a dense, ionized nebula. The hot component powers the activity observed in this system, including a dense wind and a photoionized region within the outer atmosphere of the red giant. The hot component contracted in radius at roughly constant luminosity from 1850 to 1985. Its bolometric luminosity declined by a factor of about 4 during the past 5 yr. Both the mass loss rate from the hot component and the emission activity decreased in step with the hot component's total luminosity, while photospheric radiation from the red giant companion remained essentially constant.

  19. [Evolution of Root Nodule Bacteria: Reconstruction of the Speciation Processes Resulting from Genomic Rearrangements in a Symbiotic System].

    PubMed

    Provorov, N A; Andronov, E E

    2016-01-01

    The processes of speciation and macroevolution of root nodule bacteria (rhizobia), based on deep rearrangements of their genomes and occurring in the N₂-fixing symbiotic system, are reconstructed. At the first stage of rhizobial evolution, transformation of free-living diazotrophs (related to Rhodopseudomonas) to symbiotic N₂-fixers (Bradyrhizobium) occurred due to the acquisition of the fix gene system, which is responsible for providing nitrogenase with electrons and reducing equivalents, as well as for oxygen-dependent regulation of nitrogenase synthesis in planta, and then of the nod genes responsible for the synthesis of the lipo- chito-oligosaccharide Nod factors, which induce root nodule development. The subsequent rearrangements of bacterial genomes included: (1) increased volume of hereditary information supported by species, genera (pan-genome), and individual strains; (2) transition from the unitary genome to a multicomponent one; and (3) enhanced levels of bacterial genetic plasticity and horizontal gene transfer, resulting in formation of new genera, of which Mesorhizobium, Rhizobium, and Sinorhizobium are the largest, and of over 100 species. Rhizobial evolution caused by development and diversification of the Nod factor synthesizing systems may result in both increased host specificity range (transition of Bradyrhizobium from autotrophic to symbiotrophic carbon metabolism in interaction with a broad spectrum of legumes) and to its contraction (transition of Rhizobium and Sinorhizobium to "altruistic" interaction with legumes of the galegoid clade). Reconstruction of the evolutionary pathway from symbiotic N₂-fixers to their free-living ancestors makes it possible to initiate the studies based on up-to-date genome screening technologies and aimed at the issues of genetic integration of organisms into supracpecies complexes, ratios of the macro- and microevolutionary mechanisms, and developmetn of cooperative adaptations based on altruistic

  20. Outbursts in Symbiotic Binaries

    NASA Technical Reports Server (NTRS)

    Sonneborn, George (Technical Monitor); Kenyon, Scott J.

    2004-01-01

    Two models have been proposed for the outbursts of symbiotic stars. In the thermonuclear model, outbursts begin when the hydrogen burning shell of a hot white dwarf reaches a critical mass. After a rapid increase in the luminosity and effective temperature, the white dwarf evolves at constant luminosity to lower effective temperatures, remains at optical maximum for several years, and then returns to quiescence along a white dwarf cooling curve. In disk instability models, the brightness rises when the accretion rate from the disk onto the central white dwarf abruptly increases by factors of 5-20. After a few month to several year period at maximum, both the luminosity and the effective temperature of the disk decline as the system returns to quiescence. If most symbiotic stars undergo thermonuclear eruptions, then symbiotics are probably poor candidates for type I supernovae. However, they can then provide approx. 10% of the material which stars recycle back into the interstellar medium. If disk instabilities are the dominant eruption mechanism, symbiotics are promising type Ia candidates but recycle less material into the interstellar medium.

  1. The Stellar Parameters and Evolutionary State of the Primary in the d' Symbiotic System StHα 190

    NASA Astrophysics Data System (ADS)

    Smith, Verne V.; Pereira, Claudio B.; Cunha, Katia

    2001-07-01

    We report on a high-resolution spectroscopic stellar parameter and abundance analysis of a d' symbiotic star: the yellow component of StHα190. This star has recently been discovered, and confirmed here, to be a rapidly rotating (vsini=100+/-10 km s-1) subgiant, or giant, that exhibits radial velocity variations of probably at least 40 km s-1, indicating the presence of a companion (as in many symbiotic systems, the companion is a hot white dwarf star). An analysis of the red spectrum reveals the cool stellar component to have an effective temperature of Teff=5300+/-150 K and a surface gravity of logg=3.0+/-0.5 (this corresponds to an approximate spectral type of G4 III/IV). These parameters result in an estimated primary luminosity of 45 Lsolar, implying a distance of about 780 pc (within a factor of 2). The iron and calcium abundances are found to be close to solar; however, barium is overabundant, relative to Fe and Ca, by about 0.5 dex. The Ba enhancement reflects mass transfer of s-process-enriched material when the current white dwarf was an asymptotic giant branch star, of large physical dimension (>=1 AU). The past and future evolution of this binary system depends critically on its current orbital period, which is not yet known. Concerted and frequent radial velocity measurements are needed to provide crucial physical constraints to this d' symbiotic system. Based on observations made with the 2.1 m telescope of McDonald Observatory, University of Texas.

  2. The puzzling symbiotic X-ray system 4U1700+24

    NASA Astrophysics Data System (ADS)

    Nucita, A. A.; Stefanelli, S.; De Paolis, F.; Masetti, N.; Ingrosso, G.; Del Santo, M.; Manni, L.

    2014-02-01

    Context. Symbiotic X-ray binaries form a subclass of low-mass X-ray binary systems consisting of a neutron star accreting material from a red giant donor star via stellar wind or Roche lobe overflow. Only a few confirmed members are currently known; 4U 1700+24 is a good candidate as it is a relatively bright X-ray object, possibly associated with the late-type star V934 Her. Aims: We analysed the archive XMM-Newton and Swift/XRT observations of 4U 1700+24 in order to have a uniform high-energy (0.3-10 keV) view of the source. Apart from the 2003, 2010, and 2012 data, publicly available but still unpublished, we also took the opportunity to re-analyze a set of XMM-Newton data acquired in 2002. Methods: After reducing the XMM-Newton and Swift/XRT data with standard methods, we performed a detailed spectral and timing analysis. Results: We confirmed the existence of a red-shifted O VIII Ly-α transition (already observed in the 2002 XMM-Newton data) in the high-resolution spectra collected via the RGS instruments. The red-shift of the line is found in all the analysed observations and, on average, it was estimated to be ≃0.009. We also observed a modulation of the centroid energy of the line on short time scales (a few days) and discuss the observations in the framework of different scenarios. If the modulation is due to the gravitational red-shift of the neutron star, it might arise from a sudden re-organization of the emitting X-ray matter on the scale of a few hundreds of km. Alternatively, we are witnessing a uni-polar jet of matter (with typical velocity of 1000-4000 km s-1) possibly emitted by the neutron star in an almost face-on system. The second possibility seems to be required by the apparent lack of any modulation in the observed X-ray light curve. We also note also that the low-resolution spectra (both XMM-Newton and Swift/XRT in the 0.3-10 keV band) show the existence of a black-body radiation emitted by a region (possibly associated with the neutron

  3. The Recent Evolution of a Symbiotic Ion Channel in the Legume Family Altered Ion Conductance and Improved Functionality in Calcium Signaling[C][W

    PubMed Central

    Venkateshwaran, Muthusubramanian; Cosme, Ana; Han, Lu; Banba, Mari; Satyshur, Kenneth A.; Schleiff, Enrico; Parniske, Martin; Imaizumi-Anraku, Haruko; Ané, Jean-Michel

    2012-01-01

    Arbuscular mycorrhiza and the rhizobia-legume symbiosis are two major root endosymbioses that facilitate plant nutrition. In Lotus japonicus, two symbiotic cation channels, CASTOR and POLLUX, are indispensable for the induction of nuclear calcium spiking, one of the earliest plant responses to symbiotic partner recognition. During recent evolution, a single amino acid substitution in DOES NOT MAKE INFECTIONS1 (DMI1), the POLLUX putative ortholog in the closely related Medicago truncatula, rendered the channel solo sufficient for symbiosis; castor, pollux, and castor pollux double mutants of L. japonicus were rescued by DMI1 alone, while both Lj-CASTOR and Lj-POLLUX were required for rescuing a dmi1 mutant of M. truncatula. Experimental replacement of the critical serine by an alanine in the selectivity filter of Lj-POLLUX conferred a symbiotic performance indistinguishable from DMI1. Electrophysiological characterization of DMI1 and Lj-CASTOR (wild-type and mutants) by planar lipid bilayer experiments combined with calcium imaging in Human Embryonic Kidney-293 cells expressing DMI1 (the wild type and mutants) suggest that the serine-to-alanine substitution conferred reduced conductance with a long open state to DMI1 and improved its efficiency in mediating calcium oscillations. We propose that this single amino acid replacement in the selectivity filter made DMI1 solo sufficient for symbiosis, thus explaining the selective advantage of this allele at the mechanistic level. PMID:22706284

  4. The X-ray/radio and UV luminosity expected from symbiotic systems as the progenitor of SNe Ia

    NASA Astrophysics Data System (ADS)

    Meng, Xiangcun; Han, Zhanwen

    2016-04-01

    Context. Symbiotic systems (i.e. a white dwarf + red giant star, WD + RG), which experience mass loss and form circumstellar material (CSM), have been suggested as being a possible progenitor system of type Ia supernovae (SNe Ia). After a supernova explosion, the supernova ejecta may interact with the CSM or the RG secondary. X-ray/radio emission (excess UV photons) is expected from the interaction between supernova ejecta and the CSM (RG secondary). However, no X-ray or radio emission that has originated from this type of system has been observationally detected, and only four SNe Ia have shown any possible signal of excess UV emission. These observational discrepancies need to be interpreted. Aims: We seek to determine the luminosity of these emissions, using detailed binary evolution algorithms to obtain the parameters of binary systems at the moment of the supernova explosion. Methods: We carried out a series of binary stellar evolution calculations, in which the effect of tidally enhanced wind on the evolution of WD + RG systems is incorporated. The WDs increase their mass to the Chandrasekhar mass limit, and then explode as SNe Ia. Based on the binary evolution results, we estimated the X-ray/radio (the excess UV) luminosity from the interactions between supernova ejecta and the CSM (the secondary) using a variety of published standard models. Results: We found that the X-ray flux may be high enough to be detected for a nearby SN Ia from a symbiotic system, while the radio flux is more likely to de detected when the companion is an asymptotic giant branch (AGB) star, and for a first giant branch (FGB) companion, the radio flux is generally lower than the detection limit. For two well observed SNe Ia, 2011fe and 2014J, almost all symbiotic systems are excluded by X-ray observations, but WD + FGB systems may not be ruled out by radio observations. The excess UV luminosity that results from the collision of supernova ejecta with the RG secondary may be high

  5. Physical Structure of Four Symbiotic Binaries

    NASA Technical Reports Server (NTRS)

    Kenyon, Scott J. (Principal Investigator)

    1997-01-01

    Disk accretion powers many astronomical objects, including pre-main sequence stars, interacting binary systems, and active galactic nuclei. Unfortunately, models developed to explain the behavior of disks and their surroundings - boundary layers, jets, and winds - lack much predictive power, because the physical mechanism driving disk evolution - the viscosity - is not understood. Observations of many types of accreting systems are needed to constrain the basic physics of disks and provide input for improved models. Symbiotic stars are an attractive laboratory for studying physical phenomena associated with disk accretion. These long period binaries (P(sub orb) approx. 2-3 yr) contain an evolved red giant star, a hot companion, and an ionized nebula. The secondary star usually is a white dwarf accreting material from the wind of its red giant companion. A good example of this type of symbiotic is BF Cygni: our analysis shows that disk accretion powers the nuclear burning shell of the hot white dwarf and also manages to eject material perpendicular to the orbital plane (Mikolajewska, Kenyon, and Mikolajewski 1989). The hot components in other symbiotic binaries appear powered by tidal overflow from a very evolved red giant companion. We recently completed a study of CI Cygni and demonstrated that the accreting secondary is a solar-type main sequence star, rather than a white dwarf (Kenyon et aL 1991). This project continued our study of symbiotic binary systems. Our general plan was to combine archival ultraviolet and optical spectrophotometry with high quality optical radial velocity observations to determine the variation of line and continuum sources as functions of orbital phase. We were very successful in generating orbital solutions and phasing UV+optical spectra for five systems: AG Dra, V443 Her, RW Hya, AG Peg, and AX Per. Summaries of our main results for these systems appear below. A second goal of our project was to consider general models for the

  6. Chemical Abundances of Symbiotic Giants

    NASA Astrophysics Data System (ADS)

    Gałan, C.; Mikołajewska, J.; Hinkle, K. H.; Joyce, R. R.

    2015-12-01

    High resolution (R ˜ 50000), near-IR spectra were used to measure photospheric abundances of CNO and elements around the iron peak for 24 symbiotic giants. Spectrum synthesis was employed using local thermal equilibrium and hydrostatic model atmospheres. The metallicities are distributed in a wide range with maximum around [Fe/H] ˜-0.4 - - 0.3 dex. Enrichment in 14N indicates that all the sample giants have experienced the first dredge-up. The relative abundance of [Ti/Fe] is generally large in red symbiotic systems.

  7. Evidence signaling the start of enhanced counterjet flow in the symbiotic system R AquarII

    NASA Technical Reports Server (NTRS)

    Michalitsianos, A. G.; Perez, M.; Kafatos, M.

    1994-01-01

    The velocity struture of strong far-UV emission lines observed in the symbiotic variable R Aqr suggests the start of new jet activity which will probably culminate in the appearance of a series of intense nebular emission knots within a decade. This is indicated by a systematic redward wavelength drift of emission lines, which we have followed with the International Ultraviolet Explorer (IUE) since the discovery of the brilliant northeast jet emission knots more than 10 years ago. The C IV wavelengths 1548, 1550 resonance lines, which previously showed a prominent blue asymmetric wing that extended to velocities in excess -200 km/s, exhibit red wing asymmetry that extends to speeds of approximately +200 km/s in late 1992. The C IV line profile structure is consistent with the model proposed by Solf (1993), who explains the appearance of the northeast jet knots in terms of a approximately 300-500 km/s collimated wind that collides with slower moving material expelled earlier in a nova outburst that occurred approximately 190 yr ago. Based upon these high-resolution UV spectra, similar emission structues should appear southwest of the central star when the counterwind (or stream) interacts with material in the southwest inner nebula. The apparent change in direction of flow could result from a precessing accretion disk that alters the projection angle of collimated flow from the disk poles. The direction of the collimated wind may be related to the binary orbit, because the velocity shifts associated with emission lines formed in the flow change direction on a timescale which is comparable to the binary period.

  8. Outbursts in Symbiotic Binaries

    NASA Technical Reports Server (NTRS)

    Sonneborn, George (Technical Monitor); Keyes, Charles

    2005-01-01

    A major question for symbiotic stars concerns the nature and cause of their outbursts. A small subset of symbiotics, the slow novae are fairly well established as thermonuclear events that last on the order of decades. The several symbiotic recurrent novae, which are much shorter and last on the order of months, are also thought to be thermonuclear runaways. Yet the majority of symbiotics are neither slow novae nor recurrent novae. These are the so-called classical symbiotics, many of which show outbursts whose cause is not well understood. In some cases, jets are produced in association with an outburst, therefore an investigation into the causes of outbursts will yield important insights into the production of collimated outflows. To investigate the cause and nature of classical symbiotic outbursts, we initiated a program of multiwavelength observations of these events. In FUSE Cycle 2, we obtained six observational epochs of the 2000-2002 classic symbiotic outburst in the first target of our campaign - class prototype, Z Andromedae. That program was part of a coordinated multi-wavelength Target-of-Opportunity (TOO) campaign with FUSE, XMM, Chandra, MERLIN, the VLA, and ground-based spectroscopic and high time-resolution photometric observations. Our campaign proved the concept, utility, and need for coordinated multi-wavelength observations in order to make progress in understanding the nature of the outburst mechanisms in symbiotic stars. Indeed, the FUSE data were the cornerstone of this project

  9. Infrared studies of Nova Scorpii 2014: an outburst in a symbiotic system sans an accompanying blast wave

    NASA Astrophysics Data System (ADS)

    Joshi, Vishal; Banerjee, D. P. K.; Ashok, N. M.; Venkataraman, V.; Walter, F. M.

    2015-10-01

    Near-IR (NIR) spectroscopy is presented for Nova Scorpii 2014. It is shown that the outburst occurred in a symbiotic binary system - an extremely rare configuration for a classical nova outburst to occur in but appropriate for the eruption of a recurrent nova of the T CrB class. We estimate the spectral class of secondary as M5III ± (two sub-classes). The maximum magnitude versus rate of decline relations give an unacceptably large value of 37.5 kpc for the distance. The spectra are typical of the He/N class of novae with strong He I and H lines. The profiles are broad and flat topped with full width at zero intensities approaching 9000-10 000 km s-1 and also have a sharp narrow component superposed which is attributable to emission from the giant's wind. Hot shocked gas, accompanied by X-rays and γ-rays, is expected to form when the high-velocity ejecta from the nova ploughs into the surrounding giant wind. Although X-ray emission was observed no γ-ray emission was reported. It is also puzzling that no signature of a decelerating shock is seen in the NIR, seen in similar systems like RS Oph, V745 Sco and V407 Cyg, as rapid narrowing of the line profiles. The small outburst amplitude and the giant secondary strongly suggest that Nova Sco 2014 could be a recurrent nova.

  10. Outbursts in Symbiotic Binaries

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard (Technical Monitor); Kenyon, Scott J.

    2003-01-01

    Two models have been proposed for the outbursts of symbiotic stars. In the thermonuclear model, outbursts begin when the hydrogen burning shell of a hot white dwarf reaches a critical mass. After a rapid increase in the luminosity and effective temperature, the white dwarf evolves at constant luminosity to lower effective temperatures, remains at optical maximum for several years, and then returns to quiescence along a white dwarf cooling curve. In disk instability models, the brightness rises when the accretion rate from the disk onto the central white dwarf abruptly increases by factors of 5-20. After a few month to several year period at maximum, both the luminosity and the effective temperature of the disk decline as the system returns to quiescence.

  11. Systems of symbiotic large FBRs and small CANDLE-Thorium-HTGRs

    SciTech Connect

    Ismail; Liem, P. H.; Takaki, N.; Sekimoto, H.

    2006-07-01

    Multi-component nuclear system is a system in which several types of nuclear reactors and related fuel cycle facilities are operated with mutual material exchange. A mainstay of the system is a centralized nuclear park that consists of large-scale FBRs and nuclear fuel facilities for fabrication, reprocessing and cooling/storage of nuclear fuels. The role of the FBRs is simultaneously to produce electricity and support small satellite-reactors by providing nuclear fuel. The satellite-reactors can supply energy to remote small areas. In the present study, natural uranium and thorium are charged into the FBRs in distinct fuel pin types. Under the equilibrium state, the fuels are continually discharged and separated with a certain discharge constant. Actinides, excluding {sup 233}U-only or uranium-element, are returned to the FBRs while discharged-uranium is used for fresh fuels of small HTGR thorium cycle satellite-reactors. Fissile support capability of the FBR to the satellite-reactors is investigated as function of both the FBR uranium-thorium fraction and uranium discharge constant parameters. The system shows that larger number of uranium pins is better for the FBR criticality while larger number of thorium pins and larger uranium discharge constant give better support capability. (authors)

  12. An interdisciplinary research strategy to improve symbiotic nitrogen fixation and yield of common bean (Phaseolus vulgaris) in salinised areas of the Mediterranean basin.

    PubMed

    Drevon, J J; Abdelly, C; Amarger, N; Aouani, E A; Aurag, J; Gherbi, H; Jebara, M; Lluch, C; Payre, H; Schump, O; Soussi, M; Sifi, B; Trabelsi, M

    2001-10-01

    The main findings of a cooperative research group of agronomists, plant breeders, microbiologists, physiologists and molecularists to improve the symbiotic nitrogen fixation (SNF) and N2-dependent yield of common bean under moderate salinity in the Mediterranean basin are summarised. Agronomic surveys in reference production areas show large spatial and temporal variations in plant nodulation and growth, and in efficiency of utilisation of the rhizobial symbiosis. The latter was associated with a large rhizobial diversity, including new bean nodulating species. Macrosymbiont diversity in SNF and adaptation to NaCl was found. However, contrasts between plant genotypes could be altered by specific interactions with some native rhizobia. Therefore, variations in soil rhizobial population, in addition to agronomic practices and environmental constraints, may have contributed to erratic results observed in field inoculations. At the mechanistic level, nodule C and N metabolisms, and abcissic acid content, were related to SNF potential and tolerance to NaCl. Their relation with nodule conductance to O2 diffusion was addressed by in situ hybridisation of candidate carbonic anhydrase and aquaporin genes in nodule cortex. The limits and prospects of the cooperative strategy are discussed. PMID:11566396

  13. A synergistic interaction between salt-tolerant Pseudomonas and Mesorhizobium strains improves growth and symbiotic performance of liquorice (Glycyrrhiza uralensis Fish.) under salt stress.

    PubMed

    Egamberdieva, Dilfuza; Li, Li; Lindström, Kristina; Räsänen, Leena A

    2016-03-01

    Chinese liquorice (Glycyrrhiza uralensis Fish.) is a salt-tolerant medicinal legume that could be utilized for bioremediation of salt-affected soils. We studied whether co-inoculation of the symbiotic Mesorhizobium sp. strain NWXJ19 or NWXJ31 with the plant growth-promoting Pseudomonas extremorientalis TSAU20 could restore growth, nodulation, and shoot/root nitrogen contents of salt-stressed G. uralensis, which was grown in potting soil and irrigated with 0, 50, and 75 mM NaCl solutions under greenhouse conditions. Irrigation with NaCl solutions clearly retarded the growth of uninoculated liquorice, and the higher the NaCl concentration (75 and 100 mM NaCl), the more adverse is the effect. The two Mesorhizobium strains, added either alone or in combination with P. extremorientalis TSAU20, responded differently to the salt levels used. The strain NWXJ19 was a good symbiont for plants irrigated with 50 mM NaCl, whereas the strain NWXJ31 was more efficient for plants irrigated with water or 75 mM NaCl solution. P. extremorientalis TSAU20 combined with single Mesorhizobium strains alleviated the salt stress of liquorice plants and improved yield and nodule numbers significantly in comparison with single-strain-inoculated liquorice. Both salt stress and inoculation raised the nitrogen content of shoots and roots. The nitrogen contents were at their highest, i.e., 30 and 35 % greater compared to non-stressed uninoculated plants, when plants were inoculated with P. extremorientalis TSAU20 and Mesorhizobium sp. NWXJ31 as well as irrigated with 75 mM NaCl solution. From this study, we conclude that dual inoculation with plant growth-promoting rhizobacteria could be a new approach to improve the tolerance of G. uralensis to salt stress, thereby improving its suitability for the remediation of saline lands. PMID:26585446

  14. The sexual and mating system of the shrimp Odontonia katoi (Palaemonidae, Pontoniinae), a symbiotic guest of the ascidian Polycarpa aurata in the Coral Triangle.

    PubMed

    Baeza, J Antonio; Hemphill, Carrie A; Ritson-Williams, Raphael

    2015-01-01

    Theory predicts that monogamy is adaptive in symbiotic crustaceans inhabiting relatively small and morphologically simple hosts in tropical environments where predation risk away from hosts is high. We tested this prediction in the shrimp Odontonia katoi, which inhabits the atrial chamber of the ascidian Polycarpa aurata in the Coral Triangle. Preliminary observations in O. katoi indicated that males were smaller than females, which is suggestive of sex change (protandry) in some symbiotic organisms. Thus, we first investigated the sexual system of O. katoi to determine if this shrimp was sequentially hermaphroditic. Morphological identification and size frequency distributions indicated that the population comprised males that, on average, were smaller than females. Gonad dissections demonstrated the absence of transitional individuals. Thus, O. katoi is a gonochoric species with reverse sexual dimorphism. The population distribution of O. katoi in its ascidian host did not differ significantly from a random distribution and shrimps inhabiting the same host individual as pairs were found with a frequency similar to that expected by chance alone. This is in contrast to that reported for other socially monogamous crustaceans in which pairs of heterosexual conspecifics are found in host individuals more frequently than expected by chance alone. Thus, the available information argues against monogamy in O. katoi. Furthermore, that a high frequency of solitary females were found brooding embryos and that the sex ratio was skewed toward females suggests that males might be roaming among hosts in search of receptive females in O. katoi. Symbiotic crustaceans can be used as a model system to understand the adaptive value of sexual and mating systems in marine invertebrates. PMID:25799577

  15. The Sexual and Mating System of the Shrimp Odontonia katoi (Palaemonidae, Pontoniinae), a Symbiotic Guest of the Ascidian Polycarpa aurata in the Coral Triangle

    PubMed Central

    Baeza, J. Antonio; Hemphill, Carrie A.; Ritson-Williams, Raphael

    2015-01-01

    Theory predicts that monogamy is adaptive in symbiotic crustaceans inhabiting relatively small and morphologically simple hosts in tropical environments where predation risk away from hosts is high. We tested this prediction in the shrimp Odontonia katoi, which inhabits the atrial chamber of the ascidian Polycarpa aurata in the Coral Triangle. Preliminary observations in O. katoi indicated that males were smaller than females, which is suggestive of sex change (protandry) in some symbiotic organisms. Thus, we first investigated the sexual system of O. katoi to determine if this shrimp was sequentially hermaphroditic. Morphological identification and size frequency distributions indicated that the population comprised males that, on average, were smaller than females. Gonad dissections demonstrated the absence of transitional individuals. Thus, O. katoi is a gonochoric species with reverse sexual dimorphism. The population distribution of O. katoi in its ascidian host did not differ significantly from a random distribution and shrimps inhabiting the same host individual as pairs were found with a frequency similar to that expected by chance alone. This is in contrast to that reported for other socially monogamous crustaceans in which pairs of heterosexual conspecifics are found in host individuals more frequently than expected by chance alone. Thus, the available information argues against monogamy in O. katoi. Furthermore, that a high frequency of solitary females were found brooding embryos and that the sex ratio was skewed toward females suggests that males might be roaming among hosts in search of receptive females in O. katoi. Symbiotic crustaceans can be used as a model system to understand the adaptive value of sexual and mating systems in marine invertebrates. PMID:25799577

  16. Forbidden high excitation lines and TiO bands in the symbiotic system QW SGE = MH-alpha 80-5

    NASA Astrophysics Data System (ADS)

    Calabro, E.; Mammano, A.

    1992-11-01

    The suspected symbiotic nature of MH-alpha 80-5 = AS 360 was confirmed for the first time by spectra taken in 1967 at Asiago Observatory (Marini, 1969) showing the O III and Ne III forbidden lines, together with strong He II lines and TiO bands. According to Allen (1984) nebular lines were absent in 1978, while we recorded them again in 1985. Further excitation strengthening up to forbidden Fe VII and O VI, in 1990 were noted by Munari and Buson (1991). The evolution implies density variability in the thick nebula surrounding this new variable system.

  17. Infrared Spectroscopy of Symbiotic Stars. X. Orbits for Three S-type Systems: V1044 Centauri, Hen 3-1213, and SS 73-96

    NASA Astrophysics Data System (ADS)

    Fekel, Francis C.; Hinkle, Kenneth H.; Joyce, Richard R.; Wood, Peter R.

    2015-08-01

    Employing new infrared radial velocities, we have computed orbits of the cool giants in three southern S-type symbiotic systems. The orbit for V1044 Cen, an M5.5 giant, has a period of 985 days and a modest eccentricity of 0.16. Hen 3-1213 is a K4 giant, yellow symbiotic with an orbital period of 533 days and a similar eccentricity of 0.18. For the M2 giant SS 73-96 the orbital period is 828 days, and this system has a somewhat larger eccentricity of 0.26. Measurement of the H i Paschen δ emission lines, which may at least partially reflect the motion of the secondary in SS 73-96, results in a mass ratio of 2.4 for the M giant relative to the presumed white dwarf. The estimated orbital inclinations of V1044 Cen and Hen 3-1213 are low, about 40°. However, for SS 73-96 the predicted inclination is 90°, and so an ephemeris for eclipses of the secondary or the hot nebula surrounding it is provided. A search of the orbital velocity residuals of V1044 Cen and SS 73-96 for pulsation periods produced no realistic or convincing period for either star.

  18. Symbiotic stars in X-rays

    NASA Astrophysics Data System (ADS)

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.

    2013-11-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of nine white dwarf symbiotics that were not previously known to be X-ray sources and one that had previously been detected as a supersoft X-ray source. The nine new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. The Swift/XRT telescope detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component that we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component that probably originates in a region where low-velocity shocks produce X-ray emission, i.e., a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the α/β/γ classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new δ classification

  19. Symbiotic Stars in X-rays

    NASA Technical Reports Server (NTRS)

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.

    2014-01-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. Swift/XRT detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the alpha/beta/gamma classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new sigma classification for sources with

  20. Towards Whole System Improvement

    ERIC Educational Resources Information Center

    Glatter, Ron

    2012-01-01

    The relationship between academies, and school autonomy more generally, and the wider system is a crucial issue in the battle to improve school-level education. International experience indicates that emphasising choice and competition to drive improvement is not effective and that changing structures does not yield better results for students. A…

  1. The enigmatic life history of the symbiotic crab Tunicotheres moseri (Crustacea, Brachyura, Pinnotheridae): implications for its mating system and population structure.

    PubMed

    Hernández, J E; Bolaños, J A; Palazón, J L; Hernández, G; Lira, C; Baeza, J Antonio

    2012-12-01

    Resource-monopolization theory predicts the adoption of a solitary habit in species using scarce, discrete, and small refuges. Life-history theory suggests that temporarily stable parental dwellings favor extended parental care in species that brood embryos. We tested these two predictions with the symbiotic crab Tunicotheres moseri. This species exhibits abbreviated development and inhabits the atrial chamber of the scarce, structurally simple, long-lived, and relatively small ascidian Phalusia nigra in the Caribbean. These host characteristics should favor a solitary habit and extended parental care (EPC) in T. moseri. As predicted, males and females of T. moseri inhabited ascidians solitarily with greater frequency than expected by chance alone. The male-female association pattern and reverse sexual dimorphism (males < females) additionally suggests a promiscuous "pure-search" mating system in T. moseri. Also in agreement with theoretical considerations, T. moseri displays EPC; in addition to embryos, females naturally retain larval stages, megalopae, and juveniles within their brooding pouches. This is the first record of EPC in a symbiotic crab and the second confirmed record of EPC in a marine brachyuran crab. This study supports predictions central to resource-monopolization and life-history theories. PMID:23264474

  2. A New Look at the Symbiotic Star RW Hydrae

    NASA Astrophysics Data System (ADS)

    Otulakowska-Hypka, M.; Mikolajewska, J.; Whitelock, P. A.

    2014-12-01

    We present new estimates of the basic stellar parameters of the non-eruptive, eclipsing symbiotic system, RW Hydrae. A set of photometric and spectroscopic data was used to model this object simultaneously from the light and radial velocity curves. With new spectroscopic data we were able to improve previous results known from the literature and derive physical parameters of the system: q=4.2, M1=0.8 M⊙, M2=3.4 M⊙, R1=0.2 R⊙, R2=145 R⊙, a=350 R⊙, and i=75°.

  3. SS 383: A NEW S-TYPE YELLOW SYMBIOTIC STAR?

    SciTech Connect

    Baella, N. O.; Pereira, C. B.; Miranda, L. F.

    2013-11-01

    Symbiotic stars are key objects in understanding the formation and evolution of interacting binary systems, and are probably the progenitors of Type Ia supernovae. However, the number of known symbiotic stars is much lower than predicted. We aim to search for new symbiotic stars, with particular emphasis on the S-type yellow symbiotic stars, in order to determine their total population, evolutionary timescales, and physical properties. The Two Micron All Sky Survey (2MASS) (J – H) versus (H – K {sub s}) color-color diagram has been previously used to identify new symbiotic star candidates and show that yellow symbiotics are located in a particular region of that diagram. Candidate symbiotic stars are selected on the basis of their locus in the 2MASS (J – H) versus (H – K {sub s}) diagram and the presence of Hα line emission in the Stephenson and Sanduleak Hα survey. This diagram separates S-type yellow symbiotic stars from the rest of the S-type symbiotic stars, allowing us to select candidate yellow symbiotics. To establish the true nature of the candidates, intermediate-resolution spectroscopy is obtained. We have identified the Hα emission line source SS 383 as an S-type yellow symbiotic candidate by its position in the 2MASS color-color diagram. The optical spectrum of SS 383 shows Balmer, He I, He II, and [O III] emission lines, in combination with TiO absorption bands that confirm its symbiotic nature. The derived electron density (≅10{sup 8-9} cm{sup –3}), He I emission line intensity ratios, and position in the [O III] λ5007/Hβ versus [O III] λ4363/Hγ diagram indicate that SS 383 is an S-type symbiotic star, with a probable spectral type of K7-M0 deduced for its cool component based on TiO indices. The spectral type and the position of SS 383 (corrected for reddening) in the 2MASS color-color diagram strongly suggest that SS 383 is an S-type yellow symbiotic. Our result points out that the 2MASS color-color diagram is a powerful tool in

  4. The first symbiotic stars from the LAMOST survey

    NASA Astrophysics Data System (ADS)

    Li, Jiao; Mikołajewska, Joanna; Chen, Xue-Fei; Luo, A.-Li; Rebassa-Mansergas, Alberto; Hou, Yong-Hui; Wang, Yue-Fei; Wu, Yue; Yang, Ming; Zhang, Yong; Han, Zhan-Wen

    2015-08-01

    Symbiotic stars are interacting binary systems with the longest orbital periods. They are typically formed by a white dwarf and a red giant that are embedded in a nebula. These objects are natural astrophysical laboratories for studying the evolution of binaries. Current estimates of the population of symbiotic stars in the Milky Way vary from 3000 up to 400 000. However, a current census has found less than 300. The Large sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) survey can obtain hundreds of thousands of stellar spectra per year, providing a good opportunity to search for new symbiotic stars. We detect four such binaries among 4 147 802 spectra released by LAMOST, of which two are new identifications. The first is LAMOST J12280490-014825.7, considered to be an S-type halo symbiotic star. The second is LAMOST J202629.80+423652.0, a D-type symbiotic star.

  5. Improved solar heating systems

    DOEpatents

    Schreyer, J.M.; Dorsey, G.F.

    1980-05-16

    An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

  6. Improved vortex reactor system

    DOEpatents

    Diebold, James P.; Scahill, John W.

    1995-01-01

    An improved vortex reactor system for affecting fast pyrolysis of biomass and Refuse Derived Fuel (RDF) feed materials comprising: a vortex reactor having its axis vertically disposed in relation to a jet of a horizontally disposed steam ejector that impels feed materials from a feeder and solids from a recycle loop along with a motive gas into a top part of said reactor.

  7. Improved vortex reactor system

    DOEpatents

    Diebold, J.P.; Scahill, J.W.

    1995-05-09

    An improved vortex reactor system is described for affecting fast pyrolysis of biomass and Refuse Derived Fuel (RDF) feed materials comprising: a vortex reactor having its axis vertically disposed in relation to a jet of a horizontally disposed steam ejector that impels feed materials from a feeder and solids from a recycle loop along with a motive gas into a top part of said reactor. 12 figs.

  8. Improved ranging systems

    NASA Technical Reports Server (NTRS)

    Young, Larry E.

    1989-01-01

    Spacecraft range measurements have provided the most accurate tests, to date, of some relativistic gravitational parameters, even though the measurements were made with ranging systems having error budgets of about 10 meters. Technology is now available to allow an improvement of two orders of magnitude in the accuracy of spacecraft ranging. The largest gains in accuracy result from the replacement of unstable analog components with high speed digital circuits having precisely known delays and phase shifts.

  9. Population control in symbiotic corals

    SciTech Connect

    Falkowski, P.G. ); Dubinsky, Z. ); Muscatine, L. ); McCloskey, L. )

    1993-10-01

    Stability in symbiotic association requires control of population growth between symbionts. The population density of zooxanthellae per unit surface area of most symbiotic corals is remarkably consistant. How is the population density of zooxanthellae maintained and what happens to the symbiotic association if the balance between algae and host is perturbed. The answers to these question, examined in this paper, provide a framework for understanding how the size of the component populations is controlled in symbiotic associations. The topic areas covered include the following: carbon economy in a symbiotic coral; effects of nutrient enrichment; the chemostat model of population control; the effects of exposure to ammonium levels. Ammonium ions and organic materials are the factors which maintain the density of zooxanthellae. 32 refs., 5 figs.

  10. Outbursts in Symbiotic Binaries: Z and Continued Observation

    NASA Technical Reports Server (NTRS)

    Sonneborn, George (Technical Monitor); Keyes, Charles

    2005-01-01

    A major question for symbiotic stars concerns the nature and cause of their outbursts. A small subset of symbiotics, the "slow novae" are fairly well established as thermonuclear events that last on the order of decades. The several symbiotic "recurrent novae", which are much shorter and last on the order of months, are also thought to be thermonuclear runaways. Yet the majority of symbiotics are neither slow novae nor recurrent novae. These are the so-called "classical symbiotics," many of which show outbursts whose cause is not well understood. In some cases, jets are produced in association with an outburst, therefore an investigation into the causes of outbursts will yield important insights into the production of collimated outflows. To investigate the cause and nature of classical symbiotic outbursts, we initiated a program of multi- wavelength observations of these events. First of all in FUSE Cycle 2, we obtained six observational epochs of the 2000-2002 classic symbiotic outburst in the first target of our campaign - class prototype, Z Andromedae. That program was part of a coordinated multi-wavelength Target-of-Opportunity (TOO) campaign with FUSE, XMM, Chandra, MERLIN, the VLA, and ground-based spectroscopic and high time-resolution photometric observations. Our campaign proved the concept, utility, and need for coordinated multi-wavelength observations in order to make progress in understanding the nature of the outburst mechanisms in symbiotic stars. Indeed, the FUSE data were the cornerstone of this project. The present program is a continuation of that cycle 2 effort. Indeed, the observations acquired in this program are vital to the proper interpretation of the material acquired in cycle 2 as the new data cover the critical time period when the star continues to decline from outburst and actually returns to quiescence. The utilization of these data have allowed us to refine and complete description of our new model for classical symbiotic system

  11. Improving Communications Systems

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Space Shuttle has many communications systems which are used throughout a typical mission. Given that the radio spectrum has become increasingly congested, the ability to hear extremely weak signals requires greater receiver sensitivity. Dryden Flight Research Center approached Angle Linear, a manufacturer of linear radio frequency products and peripherals for communications, to solve the problem. The solution was a receiving preamplifier specially crafted for NASA. Communications with the Space Shuttle are now more reliable,with Dryden being able to also support local missions without purchasing additional equipment. The work has carried over into the Mir Space Station communication support effort and is under evaluation by other NASA centers. The company's preamplifier line was greatly expanded to cover a broader range of frequencies, providing the same sensational improvement to other areas of communication including business, government, trucking, land mobile, cellular and broadcast.

  12. BPM System Improvements

    SciTech Connect

    Church, M.

    1991-04-24

    During the accelerator studies period of 12/90 through 1/91 the Accumulator BPM system was investigated in some detail in an effort to improve its reliability and accuracy in making closed orbit measurements. The motivation for this is to try and improve the beam energy resolution for E760. The relativistic {beta} of the {bar p} is given by {beta} = f{sub R}L/c where f{sub R} is the revolution frequency, L is the orbit length ({approx} 474050mm), and c is the speed of light. Hence, the error in {beta} is given by d{beta}/{beta} = df{sub R}/f{sub R} + dL/L. Since df{sub R}/f{sub R} is {approx} 2 x 10{sup -7}, the main contribution to the error comes from dL. During the E760 run of 5/90 to 9/90 dL was estimated to be {approx} 1mm. It is thought that this can be reduced to {approx} .25mm with proper use of the present BPM system. L is given by L = L{sub 0} + {delta}L where L{sub 0} is the accurately known orbit length of a reference orbit (extracted from an energy scan of the J/{Psi} or {Psi}{prime}), and {delta}L is the difference orbit between the current orbit and the reference orbit. SL is calculated in the 1st approximation by {delta}L = {Sigma}{sub i}C{sub i}{Sigma}{sub j}{Delta}BPM{sub ij} where {Delta}BPM{sub ij} is the horizontal difference orbit at the ith BPM in the jth sector and C{sub i} are constants depending upon the location of the BPM pickup and the strength of the quadrupoles. Table I lists the constants C{sub i}, and Fig. 1 shows a typical difference orbit, {Delta}BPM{sub ij}. These studies were all done with 'reverse protons' and concentrated on closed orbit measurements with the Accumulator horizontal BPMs. The low frequency (H=2) mode of the BPM system is used in all cases, therefore it is required that the beam be bunched with ARF3 at some level. The low frequency RF module in the BPM system had previously been modified to track the H=2 frequency.

  13. Stress as a Normal Cue in the Symbiotic Environment.

    PubMed

    Schwartzman, Julia A; Ruby, Edward G

    2016-05-01

    All multicellular hosts form associations with groups of microorganisms. These microbial communities can be taxonomically diverse and dynamic, and their persistence is due to robust, and sometimes coevolved, host-microbe and microbe-microbe interactions. Chemical and physical sources of stress are prominently situated in this molecular exchange, as cues for cellular responses in symbiotic microbes. Stress in the symbiotic environment may arise from three sources: host tissues, microbe-induced immune responses, or other microbes in the host environment. The responses of microbes to these stresses can be general or highly specialized, and collectively may contribute to the stability of the symbiotic system. In this review, we highlight recent work that emphasizes the role of stress as a cue in the symbiotic environment of plants and animals. PMID:27004825

  14. Improved multisphere spectrometer system

    SciTech Connect

    Shonka, J.J.; Schwahn, S.O.; Rogers, P.E.; Misko, C.J.

    1991-01-01

    Shonka Research Associated undertook a research program to improve the capabilities and ease of use of the Bonner sphere spectrometer system. Two key elements formed the heart of this research: replacement of the lithium iodide (LiI(Eu)) detector normally used in the spectrometer system with a spherical boron triflouride (BF{sub 3}) proportional counter and exploitation of an optimized set of nested polyethylene spheres, including boron-loaded spherical shells. Use of a spherical BF{sub 3} detector offers many advantages over the LiI(Eu) crystal. The BF{sub 3} detectors are insensitive to gamma radiation. Lack of gamma sensitivity permits acquiring data with simple electronics and allows determination of neutron spectra and dose in lower neutron-to-gamma ratio fields, including background terrestrial radiation fields. The importance of the lack of gamma sensitivity is underscored by the pending changes in neutron quality factors. The nearly perfect spherical symmetry offers advantages for BF{sub 3} over LiI(Eu) detectors as well. A light pipe, which perturbs measurements, is not needed. The bare BF{sub 3} detector response is not affected by the moderation of neutrons as is the case of the organic light pipe used with LiI(Eu). The spherical symmetry permits the use of smaller diameter shells, which add to the number of response functions.

  15. DT2008: A Promising New Genetic Resource for Improved Drought Tolerance in Soybean When Solely Dependent on Symbiotic N2 Fixation

    PubMed Central

    Sulieman, Saad; Ha, Chien Van; Nasr Esfahani, Maryam; Watanabe, Yasuko; Nishiyama, Rie; Pham, Chung Thi Bao; Nguyen, Dong Van; Tran, Lam-Son Phan

    2015-01-01

    Water deficit is one of the major constraints for soybean production in Vietnam. The soybean breeding research efforts conducted at the Agriculture Genetics Institute (AGI) of Vietnam resulted in the development of promising soybean genotypes, suitable for the drought-stressed areas in Vietnam and other countries. Such a variety, namely, DT2008, was recommended by AGI and widely used throughout the country. The aim of this work was to assess the growth of shoots, roots, and nodules of DT2008 versus Williams 82 (W82) in response to drought and subsequent rehydration in symbiotic association as a means to provide genetic resources for genomic research. Better shoot, root, and nodule growth and development were observed in the cultivar DT2008 under sufficient, water deficit, and recovery conditions. Our results represent a good foundation for further comparison of DT2008 and W82 at molecular levels using high throughput omic technologies, which will provide huge amounts of data, enabling us to understand the genetic network involved in regulation of soybean responses to water deficit and increasing the chances of developing drought-tolerant cultivars. PMID:25685802

  16. Microbiome change by symbiotic invasion in lichens.

    PubMed

    Wedin, Mats; Maier, Stefanie; Fernandez-Brime, Samantha; Cronholm, Bodil; Westberg, Martin; Grube, Martin

    2016-05-01

    Lichens are obligate symbioses between fungi and green algae or cyanobacteria. Most lichens resynthesize their symbiotic thalli from propagules, but some develop within the structures of already existing lichen symbioses. Diploschistes muscorum starts as a parasite infecting the lichen Cladonia symphycarpa and gradually develops an independent Diploschistes lichen thallus. Here we studied how this process influences lichen-associated microbiomes and photobionts by sampling four transitional stages, at sites in Sweden and Germany, and characterizing their microbial communities using high-throughput 16S rRNA gene and photobiont-specific ITS rDNA sequencing, and fluorescence in situ hybridization. A gradual microbiome shift occurred during the transition, but fractions of Cladonia-associated bacteria were retained during the process of symbiotic reorganization. Consistent changes observed across sites included a notable decrease in the relative abundance of Alphaproteobacteria with a concomitant increase in Betaproteobacteria. Armatimonadia, Spartobacteria and Acidobacteria also decreased during the infection of Cladonia by Diploschistes. The lichens differed in photobiont specificity. Cladonia symphycarpa was associated with the same algal species at all sites, but Diploschistes muscorum had a flexible strategy with different photobiont combinations at each site. This symbiotic invasion system suggests that partners can be reorganized and selected for maintaining potential roles rather than depending on particular species. PMID:26310431

  17. 3D Models of Symbiotic Binaries

    NASA Astrophysics Data System (ADS)

    Mohamed, S.; Booth, R.; Podsiadlowski, Ph.; Ramstedt, S.; Vlemmings, W.; Maercker, M.

    2015-12-01

    Symbiotic binaries consist of a cool, mass-losing giant and an accreting, compact companion. We present 3D Smoothed Particle Hydrodynamics (SPH) models of two such interacting binaries, RS Oph and Mira AB. RS Oph is also a recurrent nova system, thus we model multiple quiescent mass transfer-nova outburst cycles. The resulting circumstellar structures of both systems are highly complex with the formation of spirals, arcs, shells, equatorial and bipolar outflows. We compare the models to recent observations and discuss the implications of our results for related systems, e.g., bipolar nebulae and jets, chemically peculiar stars, and the progenitors of Type Ia supernovae.

  18. NSLS RF system improvements

    SciTech Connect

    Keane, J.; Thomas, M.; McKenzie-Wilson, R.; D'Alsace, R.; Ackerman, H.; Biscardi, R.; Langenbach, H.; Ramirez, G.

    1985-01-01

    It is required that the NSLS x-ray accelerator reach an energy of 2.5 GeV. An additional accelerating cavity and power amplifier system were installed to meet this goal. A new control system was designed to include phase and amplitude servos as well as computer interfacing. Commissioning and operating experience will be reported.

  19. Spectral and timing nature of the symbiotic X-ray binary 4U 1954+319: The slowest rotating neutron star in an X-ray binary system

    SciTech Connect

    Enoto, Teruaki; Corbet, Robin H. D.; Sasano, Makoto; Yamada, Shin'ya; Tamagawa, Toru; Makishima, Kazuo; Pottschmidt, Katja; Marcu, Diana; Fuerst, Felix; Wilms, Jörn

    2014-05-10

    The symbiotic X-ray binary (SyXB) 4U 1954+319 is a rare system hosting a peculiar neutron star (NS) and an M-type optical companion. Its ∼5.4 hr NS spin period is the longest among all known accretion-powered pulsars and exhibited large (∼7%) fluctuations over 8 yr. A spin trend transition was detected with Swift/BAT around an X-ray brightening in 2012. The source was in quiescent and bright states before and after this outburst based on 60 ks Suzaku observations in 2011 and 2012. The observed continuum is well described by a Comptonized model with the addition of a narrow 6.4 keV Fe-Kα line during the outburst. Spectral similarities to slowly rotating pulsars in high-mass X-ray binaries, its high pulsed fraction (∼60%-80%), and the location in the Corbet diagram favor high B-field (≳ 10{sup 12} G) over a weak field as in low-mass X-ray binaries. The observed low X-ray luminosity (10{sup 33}-10{sup 35} erg s{sup –1}), probable wide orbit, and a slow stellar wind of this SyXB make quasi-spherical accretion in the subsonic settling regime a plausible model. Assuming a ∼10{sup 13} G NS, this scheme can explain the ∼5.4 hr equilibrium rotation without employing the magnetar-like field (∼10{sup 16} G) required in the disk accretion case. The timescales of multiple irregular flares (∼50 s) can also be attributed to the free-fall time from the Alfvén shell for a ∼10{sup 13} G field. A physical interpretation of SyXBs beyond the canonical binary classifications is discussed.

  20. Spectral and Timing Nature of the Symbiotic X-Ray Binary 4U 1954+319: The Slowest Rotating Neutron Star in AN X-Ray Binary System

    NASA Technical Reports Server (NTRS)

    Enoto, Teruaki; Sasano, Makoto; Yamada, Shin'Ya; Tamagawa, Toru; Makishima, Kazuo; Pottschmidt, Katja; Marcu, Diana; Corbet, Robin H. D.; Fuerst, Felix; Wilms, Jorn

    2014-01-01

    The symbiotic X-ray binary (SyXB) 4U 1954+319 is a rare system hosting a peculiar neutron star (NS) and an M-type optical companion. Its approx. 5.4 hr NS spin period is the longest among all known accretion-powered pulsars and exhibited large (is approx. 7%) fluctuations over 8 yr. A spin trend transition was detected with Swift/BAT around an X-ray brightening in 2012. The source was in quiescent and bright states before and after this outburst based on 60 ks Suzaku observations in 2011 and 2012. The observed continuum is well described by a Comptonized model with the addition of a narrow 6.4 keV Fe-K alpha line during the outburst. Spectral similarities to slowly rotating pulsars in high-mass X-ray binaries, its high pulsed fraction (approx. 60%-80%), and the location in the Corbet diagram favor high B-field (approx. greater than 10(exp12) G) over a weak field as in low-mass X-ray binaries. The observed low X-ray luminosity (10(exp33)-10(exp35) erg s(exp-1)), probable wide orbit, and a slow stellar wind of this SyXB make quasi-spherical accretion in the subsonic settling regime a plausible model. Assuming a approx. 10(exp13) G NS, this scheme can explain the approx. 5.4 hr equilibrium rotation without employing the magnetar-like field (approx. 10(exp16) G) required in the disk accretion case. The timescales of multiple irregular flares (approx. 50 s) can also be attributed to the free-fall time from the Alfv´en shell for a approx. 10(exp13) G field. A physical interpretation of SyXBs beyond the canonical binary classifications is discussed.

  1. Fire alarm system improvement

    SciTech Connect

    Hodge, S.G.

    1994-10-01

    This document contains the Fire Alarm System Test Procedure for Building 234-5Z, 200-West Area on the Hanford Reservation, Richland, Washington. This Acceptance Test Procedure (ATP) has been prepared to demonstrate that the modifications to the Fire Protection systems function as required by project criteria. The ATP will test the Fire Alarm Control Panels, Flow Alarm Pressure Switch, Heat Detectors, Smoke Detectors, Flow Switches, Manual Pull Stations, and Gong/Door by Pass Switches.

  2. Analysis of the symbiotic star AG Pegasi

    NASA Technical Reports Server (NTRS)

    Keyes, C. D.; Plavec, M. J.

    1981-01-01

    High and low dispersion IUE data are analyzed in conjunction with coincident ground based spectrophotometric scans and supplementary infrared photometry of the symbiotic object AG Pegasi. The IUE observations yield an improved value of E(B-V) = 0.12. The two stellar components are easily recognized in the spectra. The cool component may be an M1.7 III star and the hot component appears to have T (sub eff) of approximately 30000 K. The emission lines observed in the ultraviolet indicate two or three distince emitting regions. Nebular component ultraviolet intercombination lines suggest an electron density of several times 10 billion/cu cm.

  3. Improved cryogenic refrigeration system

    NASA Technical Reports Server (NTRS)

    Higa, W. H.

    1967-01-01

    Two-position shuttle valve simplifies valving arrangement and crank-shaft configuration in gas-balancing and Stirling-cycle refrigeration systems used to produce temperatures below 173 degrees K. It connects the displacer and regenerator alternately to the supply line or the return line of the compressor, and establishes constant pressure on the drive piston.

  4. Improved docking alignment system

    NASA Technical Reports Server (NTRS)

    Monford, Leo G. (Inventor)

    1988-01-01

    Improved techniques are provided for the alignment of two objects. The present invention is particularly suited for 3-D translation and 3-D rotational alignment of objects in outer space. A camera is affixed to one object, such as a remote manipulator arm of the spacecraft, while the planar reflective surface is affixed to the other object, such as a grapple fixture. A monitor displays in real-time images from the camera such that the monitor displays both the reflected image of the camera and visible marking on the planar reflective surface when the objects are in proper alignment. The monitor may thus be viewed by the operator and the arm manipulated so that the reflective surface is perpendicular to the optical axis of the camera, the roll of the reflective surface is at a selected angle with respect to the camera, and the camera is spaced a pre-selected distance from the reflective surface.

  5. [Significance of hydrobiont persistent properties for symbiotic interactions].

    PubMed

    Nemtseva, N V

    2012-01-01

    Significance of symbiotic relations formed by associative symbiosis type for autochthonous and allochthonous microflora of natural water bodies is shown. Generality of symbiotic interaction mechanisms of symbionts in limnetic and halophilous communities provided by secreted factors of natural resistance from the side of the host, and by factors of persistence from the side of symbionts is proven based on a set of examples. Features of operation of lysozyme-antilysozyme, histon-antihiston, hydrogen peroxide-catalase functional systems in symbiotic interactions of autotrophic and heterotrophic components of hydrobiocenosis with dominant and associative microflora are presented. Associative microflora of allochthonous origin was shown to actively use the ecologically formed system of interaction between hydrobionts that facilitates survival of these microorganisms and preservation of their persistent potential, and as a result leads to biocenosis disorders. The knowledge obtained open new possibilities and perspectives of research of sanitary and ecological aspects of vital activity of aquatic biocenoses. PMID:22937711

  6. Carbon budgets in symbiotic associations

    SciTech Connect

    Muscatine, L.; Falkowski, P.G.; Dubinsky, Z.

    1983-01-01

    Methods are described which permit the estimation of daily budgets for photosynthetically fixed carbon in any alga-invertebrate symbiosis. Included is a method for estimating total daily translocation which does not involve the use of C-14. A daily carbon budget for a shallow water symbiotic reef coral is presented.

  7. OIT geothermal system improvements

    SciTech Connect

    Lienau, P.J.

    1996-08-01

    Three geothermal wells drilled during the original campus construction vary from 396 m (1,300 ft) to 550 m (1,800 ft). These wells supply all of the heating and part of the cooling needs of the 11-building, 62,200 m{sup 2} (670,000 ft{sup 2}) campus. The combined capacity of the well pumps is 62 L/s(980 gpm) of 89{degrees}C (192{degrees}F) geothermal fluids. Swimming pool and domestic hot water heating impose a small but nearly constant year-round flow requirement. In addition to heating, a portion of the campus is also cooled using the geothermal resource. This is accomplished through the use of an absorption chiller. The chiller, which operates on the same principle as a gas refrigerator, requires a flow of 38 L/s (600 gpm) of geothermal fluid and produces 541 kW (154 tons) of cooling capacity (Rafferty, 1989). The annual operating costs for the system is about $35,000 including maintenance salary, equipment replacement and cost of pumping. This amounts to about $0.05 per square foot per year.

  8. Discussion on selected symbiotic stars

    NASA Technical Reports Server (NTRS)

    Viotti, Roberto; Hack, Margherita

    1993-01-01

    Because of its large variety of aspects, the symbiotic phenomenon is not very suitable for a statistical treatment. It is also not clear whether symbiotic stars really represent a homogeneous group of astrophysical objects or a collection of objects of different natures but showing similar phenomena. However we are especially interested in the symbiotic phenomenon, i.e., in those physical processes occurring in the atmosphere of each individual object and in their time dependence. Such a research can be performed through the detailed analysis of individual objects. This study should be done for a time long enough to cover all the different phases of their activity, in all the spectral ranges. Since the typical time scale of the symbiotic phenomena is up to several years and decades, this represents a problem since, for instance, making astronomy outside the visual region is a quite new field of research. It was a fortunate case that a few symbiotic stars (Z And, AG Dra, CH Cyg, AX Per, and PU Vul) had undergone remarkable light variations (or 'outbursts') in recent years, which could have been followed in the space ultraviolet with IUE, and simultaneously in the optical and IR with ground-based telescopes. But, in general, the time coverage of most of the symbiotic objects is too short to have a complete picture of their behavior. In this regard, one should recall Mayall's remark about the light curve of Z And: 'Z Andromedae is another variable that shows it will require several hundred years of observations before a good analysis can be made of its variations'. This pessimistic remark should be considered as a note of caution for those involved in the interpretation of the observations. We shall discuss a number of individual symbiotic stars for which the amount of observational data is large enough to draw a rather complete picture of their general behavior and to make consistent models. We shall especially illustrate the necessary steps toward an empirical model

  9. The effect of symbiotic ant colonies on plant growth: a test using an Azteca-Cecropia system.

    PubMed

    Oliveira, Karla N; Coley, Phyllis D; Kursar, Thomas A; Kaminski, Lucas A; Moreira, Marcelo Z; Campos, Ricardo I

    2015-01-01

    In studies of ant-plant mutualisms, the role that ants play in increasing the growth rates of their plant partners is potentially a key beneficial service. In the field, we measured the growth of Cecropia glaziovii saplings and compared individuals that were naturally colonized by Azteca muelleri ants with uncolonized plants in different seasons (wet and dry). We also measured light availability as well as attributes that could be influenced by the presence of Azteca colonies, such as herbivory, leaf nutrients (total nitrogen and δ(15)N), and investments in defense (total phenolics and leaf mass per area). We found that colonized plants grew faster than uncolonized plants and experienced a lower level of herbivory in both the wet and dry seasons. Colonized plants had higher nitrogen content than uncolonized plants, although the δ(15)N, light environment, total phenolics and leaf mass per area, did not differ between colonized and uncolonized plants. Since colonized and uncolonized plants did not differ in the direct defenses that we evaluated, yet herbivory was lower in colonized plants, we conclude that biotic defenses were the most effective protection against herbivores in our system. This result supports the hypothesis that protection provided by ants is an important factor promoting plant growth. Since C. glaziovii is widely distributed among a variety of forests and ecotones, and since we demonstrated a strong relationship with their ant partners, this system can be useful for comparative studies of ant-plant interactions in different habitats. Also, given this study was carried out near the transition to the subtropics, these results help generalize the geographic distribution of this mutualism and may shed light on the persistence of the interactions in the face of climate change. PMID:25811369

  10. The Effect of Symbiotic Ant Colonies on Plant Growth: A Test Using an Azteca-Cecropia System

    PubMed Central

    Oliveira, Karla N.; Coley, Phyllis D.; Kursar, Thomas A.; Kaminski, Lucas A.; Moreira, Marcelo Z.; Campos, Ricardo I.

    2015-01-01

    In studies of ant-plant mutualisms, the role that ants play in increasing the growth rates of their plant partners is potentially a key beneficial service. In the field, we measured the growth of Cecropia glaziovii saplings and compared individuals that were naturally colonized by Azteca muelleri ants with uncolonized plants in different seasons (wet and dry). We also measured light availability as well as attributes that could be influenced by the presence of Azteca colonies, such as herbivory, leaf nutrients (total nitrogen and δ15N), and investments in defense (total phenolics and leaf mass per area). We found that colonized plants grew faster than uncolonized plants and experienced a lower level of herbivory in both the wet and dry seasons. Colonized plants had higher nitrogen content than uncolonized plants, although the δ15N, light environment, total phenolics and leaf mass per area, did not differ between colonized and uncolonized plants. Since colonized and uncolonized plants did not differ in the direct defenses that we evaluated, yet herbivory was lower in colonized plants, we conclude that biotic defenses were the most effective protection against herbivores in our system. This result supports the hypothesis that protection provided by ants is an important factor promoting plant growth. Since C. glaziovii is widely distributed among a variety of forests and ecotones, and since we demonstrated a strong relationship with their ant partners, this system can be useful for comparative studies of ant-plant interactions in different habitats. Also, given this study was carried out near the transition to the subtropics, these results help generalize the geographic distribution of this mutualism and may shed light on the persistence of the interactions in the face of climate change. PMID:25811369

  11. Improving an Imperfect Metric System

    ERIC Educational Resources Information Center

    Frasier, E. Lewis

    1974-01-01

    Suggests some improvements and additional units necessary for the International Metric System to expand its use to all measureable entities and defined quantities, especially in the measurement of time and angles. Included are tables of proposed unit systems in contrast with the presently available systems. (CC)

  12. Outbursts In Symbiotic Binaries (FUSE 2000)

    NASA Technical Reports Server (NTRS)

    Kenyon, Scott J.; Sonneborn, George (Technical Monitor)

    2002-01-01

    with line variations - will yield physical parameters for the expanding shell of gas in the outer atmosphere of the hot component. We also worked on several diagnostic tools, including upgrades to photoionization programs developed by the PI and others. We plan to use these tools to derive electron densities and temperatures front intercombination and forbidden lines observed on optical and FUSE spectra. Preliminary results indicate a large electron density, n(sub e) is greater than or = 10(exp 10)/cc and a modest electron temperature, T(sub e) approx. 20,000 K. We see no evidence for shocked gas as observed in some other symbiotics. However, we have yet to include several important lines of [Fe VII] and [Ne V] in the analysis. Inclusion of these lines will yield an improved estimate of the electron temperature in the gas. Finally, we have one additional FUSE spectrum planned for acquisition during this cycle. These data will provide important information concerning the state of the system farther along in its decline. Once we have this spectrum in hand, we plan to complete our analysis and publish our results.

  13. Formation of broad Balmer wings in symbiotic stars

    NASA Astrophysics Data System (ADS)

    Chang, Seok-Jun; Heo, Jeong-Eun; Hong, Chae-Lin; Lee, Hee-Won

    2016-07-01

    Symbiotic stars are binary systems composed of a hot white dwarf and a mass losing giant. In addition to many prominent emission lines symbiotic stars exhibit Raman scattered O VI features at 6825 and 7088 Å. Another notable feature present in the spectra of many symbiotics is the broad wings around Balmer lines. Astrophysical mechanisms that can produce broad wings include Thomson scattering by free electrons and Raman scattering of Ly,β and higher series by neutral hydrogen. In this poster presentation we produce broad wings around Hα and H,β adopting a Monte Carlo techinique in order to make a quantitative comparison of these two mechanisms. Thomson wings are characterized by the exponential cutoff given by the termal width whereas the Raman wings are dependent on the column density and continuum shape in the far UV region. A brief discussion is provided.

  14. Innate immunity underlies symbiotic relationships.

    PubMed

    Kisseleva, E P

    2014-12-01

    Here, the modern data regarding interactions between normal microbiota and barrier tissues in plants, humans and animals are reviewed. The main homeostatic mechanisms responsible for interactions between epithelium and innate immune cells with symbiotic bacteria are described. A key step in this process is recognition of soluble microbial products by ligation to pattern-recognition receptors expressed on the host cells. As a result, epithelial cells secrete mucus, antibacterial peptides and immunoregulatory molecules. The main outcomes from immunological reactions towards symbiotic bacteria involve development of conditions for formation and maintenance of microbial biocenosis as well as providing safety for the host. Also, it is considered important to preserve and transfer beneficial bacteria to progeny. PMID:25716721

  15. Innoculation of Almond Rootstock with Symbiotic Arbuscular Mycorrhizal Fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil borne arbuscular mycorrhizal (AM) fungus forms a symbiotic (mutualistic) relationship with most plants. The fungus colonizes the root and grows out into the soil. Hyphae net work, the part of the fungus that's in the soil acts as an extension of the root system. The scope of the research is to ...

  16. V479 And: CV, LMXB, or Symbiotic?

    NASA Astrophysics Data System (ADS)

    Buitrago, Diego González; Tovmassian, Gagik; Echevarría, Juan; Zharikov, Sergey; Miyaji, Takamitsu; Avilés, Andres; Valyavin, Gennady

    2013-01-01

    V479 And is a 14.26 hour, close binary system, comprised of a G8-K0 star departing from the main sequence and a compact primary star accreting matter from the donor. The object is an X-ray source, modulated with the orbital period. This, and the presence of an intense He II line, leads us to speculate that the compact object is a magnetic white dwarf. However, we do not find strong constraints on the upper mass limit of the compact object, and we may have a neutron star in a low mass X-ray binary instead of a cataclysmic variable. The orbital period is certainly too short for the donor star to be an evolved giant star, so classifying this object as a symbiotic binary may be a big stretch; however there is an evidence that the mass transfer occurs via stellar winds, rather than through the L1 point of Roche filling secondary, a phenomenon more common for symbiotic stars.

  17. Monogamy in a Hyper-Symbiotic Shrimp

    PubMed Central

    Baeza, J. Antonio; Simpson, Lunden; Ambrosio, Louis J.; Guéron, Rodrigo; Mora, Nathalia

    2016-01-01

    Theory predicts that monogamy is adaptive in resource-specialist symbiotic crustaceans inhabiting relatively small and morphologically simple hosts in tropical environments where predation risk away from hosts is high. We tested this prediction in Pontonia manningi, a hyper-symbiotic shrimp that dwells in the mantle cavity of the Atlantic winged oyster Pteria colymbus that, in turn, infects gorgonians from the genus Pseudopterogorgia in the Caribbean Sea. In agreement with theory, P. manningi were found dwelling as heterosexual pairs in oysters more frequently than expected by chance alone. Males and females also inhabited the same host individual independent of the female gravid condition or of the developmental stage of brooded embryos. While the observations above argue in favor of monogamy in P. manningi, there is evidence to suggest that males of the studied species are moderately promiscuous. That females found living solitary in oysters most often brooded embryos, and that males allocated more to weaponry (major claw size) than females at any given size suggest that males might be roaming among host individuals in search of and, fighting for, receptive females. All available information depicts a rather complex mating system in P. manningi: primarily monogamous but with moderately promiscuous males. PMID:26934109

  18. Monogamy in a Hyper-Symbiotic Shrimp.

    PubMed

    Baeza, J Antonio; Simpson, Lunden; Ambrosio, Louis J; Guéron, Rodrigo; Mora, Nathalia

    2016-01-01

    Theory predicts that monogamy is adaptive in resource-specialist symbiotic crustaceans inhabiting relatively small and morphologically simple hosts in tropical environments where predation risk away from hosts is high. We tested this prediction in Pontonia manningi, a hyper-symbiotic shrimp that dwells in the mantle cavity of the Atlantic winged oyster Pteria colymbus that, in turn, infects gorgonians from the genus Pseudopterogorgia in the Caribbean Sea. In agreement with theory, P. manningi were found dwelling as heterosexual pairs in oysters more frequently than expected by chance alone. Males and females also inhabited the same host individual independent of the female gravid condition or of the developmental stage of brooded embryos. While the observations above argue in favor of monogamy in P. manningi, there is evidence to suggest that males of the studied species are moderately promiscuous. That females found living solitary in oysters most often brooded embryos, and that males allocated more to weaponry (major claw size) than females at any given size suggest that males might be roaming among host individuals in search of and, fighting for, receptive females. All available information depicts a rather complex mating system in P. manningi: primarily monogamous but with moderately promiscuous males. PMID:26934109

  19. Leading System-Wide Improvement

    ERIC Educational Resources Information Center

    Harris, Alma

    2012-01-01

    Around the world there is a preoccupation with improving the performance of schools and school systems. Comparisons made between countries through PISA and PERLs have led to a preoccupation, and in some cases, an obsession, with securing a high position in the international league tables. The minds of policy-makers and politicians alike are…

  20. Ozone measurement systems improvements studies

    NASA Technical Reports Server (NTRS)

    Thomas, R. W.; Guard, K.; Holland, A. C.; Spurling, J. F.

    1974-01-01

    Results are summarized of an initial study of techniques for measuring atmospheric ozone, carried out as the first phase of a program to improve ozone measurement techniques. The study concentrated on two measurement systems, the electro chemical cell (ECC) ozonesonde and the Dobson ozone spectrophotometer, and consisted of two tasks. The first task consisted of error modeling and system error analysis of the two measurement systems. Under the second task a Monte-Carlo model of the Dobson ozone measurement technique was developed and programmed for computer operation.

  1. Molecular and biochemical analysis of symbiotic plant receptor kinase complexes

    SciTech Connect

    Cook, Douglas R; Riely, Brendan K

    2010-09-01

    DE-FG02-01ER15200 was a 36-month project, initiated on Sept 1, 2005 and extended with a one-year no cost extension to August 31, 2009. During the project period we published seven manuscripts (2 in review). Including the prior project period (2002-2005) we published 12 manuscripts in journals that include Science, PNAS, The Plant Cell, Plant Journal, Plant Physiology, and MPMI. The primary focus of this work was to further elucidate the function of the Nod factor signaling pathway that is involved in initiation of the legume-rhizobium symbiosis and in particular to explore the relationship between receptor kinase-like proteins and downstream effectors of symbiotic development. During the project period we have map-base cloned two additional players in symbiotic development, including an ERF transcription factor and an ethylene pathway gene (EIN2) that negatively regulates symbiotic signaling; we have also further characterized the subcellular distribution and function of a nuclear-localized symbiosis-specific ion channel, DMI1. The major outcome of the work has been the development of systems for exploring and validating protein-protein interactions that connect symbiotic receptor-like proteins to downstream responses. In this regard, we have developed both homologous (i.e., in planta) and heterologous (i.e., in yeast) systems to test protein interactions. Using yeast 2-hybrid screens we isolated the only known interactor of the nuclear-localized calcium-responsive kinase DMI3. We have also used yeast 2-hybrid methodology to identify interactions between symbiotic signaling proteins and certain RopGTPase/RopGEF proteins that regulate root hair polar growth. More important to the long-term goals of our work, we have established a TAP tagging system that identifies in planta interactions based on co-immuno precipitation and mass spectrometry. The validity of this approach has been shown using known interactors that either co-iummnoprecipate (i.e., remorin) or co

  2. Discovery of true, likely and possible symbiotic stars in the dwarf spheroidal NGC 205

    NASA Astrophysics Data System (ADS)

    Gonçalves, Denise R.; Magrini, Laura; de la Rosa, Ignacio G.; Akras, Stavros

    2015-02-01

    In this paper we discuss the photometric and spectroscopic observations of newly discovered (symbiotic) systems in the dwarf spheroidal galaxy NGC 205. The Gemini Multi-Object Spectrograph on-off band [O III] 5007 Å emission imaging highlighted several [O III] line emitters, for which optical spectra were then obtained. The detailed study of the spectra of three objects allows us to identify them as true, likely and possible symbiotic systems (SySts), the first ones discovered in this galaxy. SySt-1 is unambiguously classified as a symbiotic star, because of the presence of unique emission lines which belong only to symbiotic spectra, the well-known O VI Raman-scattered lines. SySt-2 is only possibly a SySt because the Ne VII Raman-scattered line at 4881 Å, recently identified in a well-studied Galactic symbiotic as another very conspicuous property of symbiotic, could as well be identified as N III or [Fe III]. Finally, SySt-3 is likely a symbiotic binary because in the red part of the spectrum it shows the continuum of a late giant, and forbidden lines of moderate to high ionization, like [Fe V] 4180 Å. The main source for scepticism on the symbiotic nature of the latter systems is their location in the planetary nebula region in the [O III]4363/Hγ versus [O III]5007/Hβ diagnostic diagram. It is worth mentioning that at least another two confirmed symbiotics, one of the Local Group dwarf spheroidal IC 10 and the other of the Galaxy, are also misplaced in this diagram.

  3. Optical Variability of X-Ray Bright Southern Symbiotic Stars

    NASA Astrophysics Data System (ADS)

    Hedrick, C.; Sokoloski, J.

    2004-12-01

    We performed weekly B- and V-band observations of four X-ray bright southern symbiotic binary stars -- CD-43 14304, Hen 3-1591, LMC S63, and SMC LN 358 -- using the 1.3-m telescope at Cerro Tololo Inter-American Observatory (CTIO). We began optical monitoring in August 2003 for two of the objects (LMC S63 and SMC LN 358) and in January 2004 for the other two objects (CD-43 14304 and Hen 3-1591). None of the four survey objects experienced a major outburst during the monitoring period. We did, however, detect small-amplitude ( 0.1 mag) optical variability on a time scale of tens of days, for the first time, in each of the four systems. Both the structure and amplitude of the variations are roughly the same in the B band and V band in all of the symbiotics in our sample except one (LMC S63), and is most consistent with the idea that the week-time-scale variability originates with the hot component (most likely an accreting white dwarf) rather than the red giant. We compare the variability properties of our small sample of X-ray-bright symbiotic stars to those of samples of both X-ray-bright and X-ray-dim symbiotic stars from the database of the American Association of Variable Star Observers (AAVSO).

  4. Characteristics of the hot components of symbiotic stars

    NASA Astrophysics Data System (ADS)

    Burmeister, Mari

    2010-08-01

    Symbiotic stars are interacting binaries whose components are a red giant and a small hot star, usually a white dwarf. The intensive stellar wind from the giant is captured by the companion, giving rise to strong emission lines in the spectra and a range of phenomena, which may include the formation of an accretion disk and the ejection of collimated jets. In this thesis, four symbiotic stars, as different as possible, were chosen for a spectral investigation of the symbiotic phenomenon. Of those, Z Andromedae is a so-called classical symbiotic star with a hot companion that shows a characteristic pattern of brightenings (outbursts). AG Draconis is a bright system like Z Andromedae and shows similar activity, but has an unusually hot yellow donor star. CH Cygni and EG Andromedae have, on the contrary, relatively dim white dwarfs. The former shows irregular outbursts, the origin of which is not easy to explain, the latter is one of the quiet symbiotic stars with no outburst yet recorded. Each of those four stars was observed for at least ten years with the 1.5-m telescope at Tartu Observatory. Several outbursts of Z Andromedae and AG Draconis were witnessed, as well as substantial changes in the CH Cygni spectra. The perhaps most surprising result was the discovery of collimated jets in Z Andromedae spectra on two instances, an event never observed in this star before. In CH Cygni, evidence for the existence of an accretion disk in 1998 was discovered. EG Andromedae stayed quiet and the only changes in its spectra could be ascribed to orbital motion. We found that not all the outbursts of Z Andromedae and AG Draconis are accompanied by similar changes in the spectra: during some brightenings the stars become hotter, during some, cooler. The existence of the disk in CH Cygni in 1998 affirms that the formation of such a structure is possible in symbiotic stars. Moreover, as the ejection of jets is associated to an accretion disk, the jets in Z Andromedae can also be

  5. Molecular Basis of Symbiotic Promiscuity

    PubMed Central

    Perret, Xavier; Staehelin, Christian; Broughton, William J.

    2000-01-01

    Eukaryotes often form symbioses with microorganisms. Among these, associations between plants and nitrogen-fixing bacteria are responsible for the nitrogen input into various ecological niches. Plants of many different families have evolved the capacity to develop root or stem nodules with diverse genera of soil bacteria. Of these, symbioses between legumes and rhizobia (Azorhizobium, Bradyrhizobium, Mesorhizobium, and Rhizobium) are the most important from an agricultural perspective. Nitrogen-fixing nodules arise when symbiotic rhizobia penetrate their hosts in a strictly controlled and coordinated manner. Molecular codes are exchanged between the symbionts in the rhizosphere to select compatible rhizobia from pathogens. Entry into the plant is restricted to bacteria that have the “keys” to a succession of legume “doors”. Some symbionts intimately associate with many different partners (and are thus promiscuous), while others are more selective and have a narrow host range. For historical reasons, narrow host range has been more intensively investigated than promiscuity. In our view, this has given a false impression of specificity in legume-Rhizobium associations. Rather, we suggest that restricted host ranges are limited to specific niches and represent specialization of widespread and more ancestral promiscuous symbioses. Here we analyze the molecular mechanisms governing symbiotic promiscuity in rhizobia and show that it is controlled by a number of molecular keys. PMID:10704479

  6. Symbiotic stars in X-rays and UV

    NASA Astrophysics Data System (ADS)

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.; Nuñez, N. E.

    2014-10-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. I will describe the detection with the Swift/XRT of 14 white dwarf symbiotics that were not previously known to be X-ray sources. The 14 new X-ray detections were the result of a survey of more than 50 symbiotic stars using Swift fill-in programs during three years. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. Simultaneous Swift/UVOT data allowed us to find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, the UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk.

  7. An improved criticality alarm system

    SciTech Connect

    Tyree, W.H.; Gilpin, H.E.; Balmer, D.K.; Vennitti, D.A.

    1991-12-31

    The Rocky Flats Plant near Golden, Colorado is the primary facility for the production of plutonium components used in the US arsenal of nuclear weapons. It is operated by EG&G under contract to the US Department of Energy (DOE). There are ten production buildings on plant site with neutron based criticality alarm systems. These systems have been in operation for the past seventeen years. Changes in the interpretation of A.N.S.I. standards and DOE orders have precipitated an evaluation of detector sensitivity and placement criteria. As a result of this evaluation, improvements in detector design and calibration have improved detector sensitivity by a factor of six. Testing performed on the design defined a minimum sensitivity as required by A.N.S.I. 8.3 and provided information for saturation and survivability for a fission event of up to 1 {times} 10{sup 17} fissions in 80 microseconds. A rigorous testing and calibration program has been developed and is in place. Neutron sensitivity is certified at a nearby reactor which is traceable to N.I.S.T.. 4 refs.

  8. Circumstellar Dust in Symbiotic Novae

    NASA Astrophysics Data System (ADS)

    Jurkic, T.; Kotnik-Karuza, D.

    2015-12-01

    We present a model of inner dust regions around the cool Mira component of the two symbiotic novae, RR Tel and HM Sge, based on the near-IR photometry, ISO spectra and mid-IR interferometry. The dust properties were determined using the DUSTY code. A compact circumstellar silicate dust shell with inner dust shell temperatures between 900 K and 1300 K and of moderate optical depth can explain all the observations. RR Tel shows the presence of an equatorially enhanced dust density during minimum obscuration. Obscuration events are explained by an increase in optical depth caused by the newly condensed dust. The mass loss rates are significantly higher than in intermediate-period single Miras but in agreement with longer-period O-rich AGB stars.

  9. IUE observations of symbiotic stars

    NASA Technical Reports Server (NTRS)

    Hack, M.

    1982-01-01

    The main photometric and spectroscopic characteristics in the ultraviolet and visual range of the most extensively studied symbiotic stars are reviewed. The main data obtained with IUE concern: (1) the determination of the shape of the UV continuum, which, in some cases, proves without doubt the presence of a hot companion; and the determination of the interstellar extinction by means of the lambda 2200 feature; (2) the measurement of emission lines, which enables us to derive the electron temperature and density of the circumstellar envelope, and, taken together with those lines observed in the visual, give more complete information on which spectroscopic mechanisms operate in the envelope; (3) the observation of absorption lines in the UV, which are present in just a few cases.

  10. Ultraviolet properties of the symbiotic stars

    NASA Technical Reports Server (NTRS)

    Slovak, M. H.; Lambert, D. L.

    1982-01-01

    A general discussion of the UV spectra of symbiotic stars, including both the emission lines and the continua, is presented, with AG Pegasi considered as an illustrative example. It is noted that the IUE observations of the symbiotics have revealed UV properties which rival the diversity of the optical features. Nevertheless, the UV data have for the first time permitted the hot component to be studied relatively uncontaminated by the giant companion, which dominates the optical regime. The UV observations provide convincing evidence that many of the symbiotics have hot stellar companions embedded in the enshrouding nebula or accretion shell formed from the wind from one or possibly both of the components.

  11. TIDALLY ENHANCED STELLAR WIND: A WAY TO MAKE THE SYMBIOTIC CHANNEL TO TYPE Ia SUPERNOVA VIABLE

    SciTech Connect

    Chen, X.; Han, Z.

    2011-07-10

    In the symbiotic (or WD+RG) channel of the single-degenerate scenario for type Ia supernovae (SNe Ia), the explosions occur a relatively long time after star formation. The birthrate from this channel would be too low to account for all observed SNe Ia were it not for some mechanism to enhance the rate of accretion on to the white dwarf. A tidally enhanced stellar wind, of the type which has been postulated to explain many phenomena related to giant star evolution in binary systems, can do this. Compared to mass stripping, this model extends the space of SNe Ia progenitors to longer orbital periods and hence increases the birthrate to about 0.0069 yr{sup -1} for the symbiotic channel. Two symbiotic stars, T CrB and RS Oph, considered to be the most likely progenitors of SNe Ia through the symbiotic channel, are well inside the period-companion mass space predicted by our models.

  12. INFRARED SPECTROSCOPY OF SYMBIOTIC STARS. IX. D-TYPE SYMBIOTIC NOVAE

    SciTech Connect

    Hinkle, Kenneth H.; Joyce, Richard R.; Fekel, Francis C.; Wood, Peter E-mail: joyce@noao.edu E-mail: wood@mso.anu.edu.au

    2013-06-10

    Time-series spectra of the near-infrared 1.6 {mu}m region have been obtained for five of the six known D-type symbiotic novae. The spectra map the pulsation kinematics of the Mira component in the Mira-white dwarf binary system and provide the center-of-mass velocity for the Mira. No orbital motion is detected in agreement with previous estimates of orbital periods {approx}>100 yr and semimajor axes {approx}50 AU. The 1-5 {mu}m spectra of the Miras show line weakening during dust obscuration events. This results from scattering and continuum emission by 1000 K dust. In the heavily obscured HM Sge system the 4.6 {mu}m CO spectrum formed in 1000 K gas is seen in emission against an optically thick dust continuum. Spectral features that are typically produced in either the cool molecular region or the expanding circumstellar region of late-type stars cannot be detected in the D-symbiotic novae. This is in accord with the colliding wind model for interaction between the white dwarf and Mira. Arguments are presented that the 1000 K gas and dust are not Mira circumstellar material but are in the wind interaction region of the colliding winds. CO is the first molecule detected in this region. We suggest that dust condensing in the intershock region is the origin of the dust obscuration. This model explains variations in the obscuration. Toward the highly obscured Mira in HM Sge the dust zone is estimated to be {approx}0.1 AU thick. The intershock wind interaction zone appears thinnest in the most active systems. Drawing on multiple arguments masses are estimated for the system components. The Miras in most D-symbiotic novae have descended from intermediate mass progenitors. The large amount of mass lost from the Mira combined with the massive white dwarf companion suggests that these systems are supernova candidates. However, timescales and the number of objects make these rare events.

  13. Symbiotic control of mosquito borne disease.

    PubMed

    Ricci, Irene; Valzano, Matteo; Ulissi, Ulisse; Epis, Sara; Cappelli, Alessia; Favia, Guido

    2012-11-01

    It is well accepted that the symbiotic relationships insects have established with several microorganisms have had a key role in their evolutionary success. Bacterial symbiosis is also prevalent in insects that are efficient disease vectors, and numerous studies have sought to decrypt the basic mechanisms of the host-symbiont relationships and develop ways to control vector borne diseases. 'Symbiotic control', a new multifaceted approach that uses symbiotic microorganisms to control insect pests or reduce vector competence, seems particularly promising. Three such approaches currently at the cutting edge are: (1) the disruption of microbial symbionts required by insect pests; (2) the manipulation of symbionts that can express anti-pathogen molecules within the host; and (3) the introduction of endogenous microbes that affect life-span and vector capacity of the new hosts in insect populations. This work reviews current knowledge on microbial symbiosis in mosquitoes that holds promise for development of symbiotic control for mosquito borne diseases. PMID:23265608

  14. The Bright Symbiotic Mira EF Aquilae

    NASA Astrophysics Data System (ADS)

    Margon, Bruce; Prochaska, J. Xavier; Tejos, Nicolas; Monroe, TalaWanda

    2016-02-01

    An incidental spectrum of the poorly studied long-period variable EF Aquilae shows [O III] emission indicative of a symbiotic star. Strong GALEX detections in the UV reinforce this classification, providing overt evidence for the presence of the hot subluminous companion. Recent compilations of the photometric behavior strongly suggest that the cool component is a Mira variable. Thus EF Aql appears to be a member of the rare symbiotic Mira subgroup.

  15. Obtaining hemocytes from the Hawaiian bobtail squid Euprymna scolopes and observing their adherence to symbiotic and non-symbiotic bacteria.

    PubMed

    Collins, Andrew J; Nyholm, Spencer V

    2010-01-01

    Studies concerning the role of the immune system in mediating molecular signaling between beneficial bacteria and their hosts have, in recent years, made significant contributions to our understanding of the co-evolution of eukaryotes with their microbiota. The symbiotic association between the Hawaiian bobtail squid, Euprymna scolopes and the bioluminescent bacterium Vibrio fischeri has been utilized as a model system for understanding the effects of beneficial bacteria on animal development. Recent studies have shown that macrophage-like hemocytes, the sole cellular component of the squid host's innate immune system, likely play an important role in mediating the establishment and maintenance of this association. This protocol will demonstrate how to obtain hemocytes from E. scolopes and then use these cells in bacterial binding assays. Adult squid are first anesthetized before hemolymph is collected by syringe from the main cephalic blood vessel. The host hemocytes, contained in the extracted hemolymph, are adhered to chambered glass coverslips and then exposed to green fluorescent protein-labeled symbiotic Vibrio fischeri and non-symbiotic Vibrio harveyi. The hemocytes are counterstained with a fluorescent dye (Cell Tracker Orange, Invitrogen) and then visualized using fluorescent microscopy. PMID:20150890

  16. Circumstellar dust in symbiotic novae

    NASA Astrophysics Data System (ADS)

    Jurkic, Tomislav; Kotnik-Karuza, Dubravka

    2015-08-01

    Physical properties of the circumstellar dust and associated physical mechanisms play an important role in understanding evolution of symbiotic binaries. We present a model of inner dust regions around the cool Mira component of the two symbiotic novae, RR Tel and HM Sge, based on the long-term near-IR photometry, infrared ISO spectra and mid-IR interferometry. Pulsation properties and long-term variabilities were found from the near-IR light curves. The dust properties were determined using the DUSTY code which solves the radiative transfer. No changes in pulsational parameters were found, but a long-term variations with periods of 20-25 years have been detected which cannot be attributed to orbital motion.Circumstellar silicate dust shell with inner dust shell temperatures between 900 K and 1300 K and of moderate optical depth can explain all the observations. RR Tel showed the presence of an optically thin CS dust envelope and an optically thick dust region outside the line of sight, which was further supported by the detailed modelling using the 2D LELUYA code. Obscuration events in RR Tel were explained by an increase in optical depth caused by the newly condensed dust leading to the formation of a compact dust shell. HM Sge showed permanent obscuration and a presence of a compact dust shell with a variable optical depth. Scattering of the near-IR colours can be understood by a change in sublimation temperature caused by the Mira variability. Presence of large dust grains (up to 4 µm) suggests an increased grain growth in conditions of increased mass loss. The mass loss rates of up to 17·10-6 MSun/yr were significantly higher than in intermediate-period single Miras and in agreement with longer-period O-rich AGB stars.Despite the nova outburst, HM Sge remained enshrouded in dust with no significant dust destruction. The existence of unperturbed dust shell suggests a small influence of the hot component and strong dust shielding from the UV flux. By the use

  17. Symbiotic structures to significantly enhance space missions

    NASA Astrophysics Data System (ADS)

    Williams, Andrew D.; Diaz-Aguado, Millan; Arritt, Brandon J.

    2007-04-01

    The Department of Defense is actively pursuing a Responsive Space capability that will dramatically reduce the cost and time associated with getting a payload into space. In order to enable that capability, our space systems must be modular and flexible to cover a wide range of missions, configurations, duty cycles, and orbits. This places requirements on the entire satellite infrastructure: payloads, avionics, electrical harnessing, structure, thermal management system, etc. The Integrated Structural Systems Team at the Air Force Research Laboratory, Space Vehicles Directorate, has been tasked with developing structural and thermal solutions that will enable a Responsive Space capability. This paper details a "symbiotic" solution where thermal management functionality is embedded within the structure of the satellite. This approach is based on the flight proven and structurally efficient isogrid architecture. In our rendition, the ribs serve as fluidic passages for thermal management, and passively activated valves are used to control flow to the individual components. As the paper will explain, our analysis has shown this design to be structurally efficient and thermally responsive to a wide range of potential satellite missions, payloads, configurations, and orbits.

  18. The Frankia alni symbiotic transcriptome.

    PubMed

    Alloisio, Nicole; Queiroux, Clothilde; Fournier, Pascale; Pujic, Petar; Normand, Philippe; Vallenet, David; Médigue, Claudine; Yamaura, Masatoshi; Kakoi, Kentaro; Kucho, Ken-ichi

    2010-05-01

    The actinobacteria Frankia spp. are able to induce the formation of nodules on the roots of a large spectrum of actinorhizal plants, where they convert dinitrogen to ammonia in exchange for plant photosynthates. In the present study, transcriptional analyses were performed on nitrogen-replete free-living Frankia alni cells and on Alnus glutinosa nodule bacteria, using whole-genome microarrays. Distribution of nodule-induced genes on the genome was found to be mostly over regions with high synteny between three Frankia spp. genomes, while nodule-repressed genes, which were mostly hypothetical and not conserved, were spread around the genome. Genes known to be related to nitrogen fixation were highly induced, nif (nitrogenase), hup2 (hydrogenase uptake), suf (sulfur-iron cluster), and shc (hopanoids synthesis). The expression of genes involved in ammonium assimilation and transport was strongly modified, suggesting that bacteria ammonium assimilation was limited. Genes involved in particular in transcriptional regulation, signaling processes, protein drug export, protein secretion, lipopolysaccharide, and peptidoglycan biosynthesis that may play a role in symbiosis were also identified. We also showed that this Frankia symbiotic transcriptome was highly similar among phylogenetically distant plant families Betulaceae and Myricaceae. Finally, comparison with rhizobia transcriptome suggested that F. alni is metabolically more active in symbiosis than rhizobia. PMID:20367468

  19. [A psychotic symbiotic child. Clinical and psychopathological study].

    PubMed

    Ledoux, M H

    1993-01-01

    Through the case study of a psychotic girl, we have tried to outline the psychotic mechanisms involved in this mental functioning. Anxieties of an autistic type have been found, as well as anxieties of a more psychotic type (i.e. symbiotic and schizophrenic). Characteristics of this psychotic functioning were: omnipotence, primitive identification mechanisms, fragmenting separation anxiety, search for sameness and for a low of identical repetition, difficulties in accessing to symbolism. Difficulties in defusion from the symbiotic object and the potential role played by this object in the difficulties are noteworthy. But it is not possible to conceptualize them in terms of direct causal relationship, because the object has also a counterphobic function and compensates for the void of subject as well as for the dissolution of the self. Also present is a schizoparanoïd aspect, with a temptation to cuddle inside the object. The sudden breaking through of informations or requirements from reality provokes surprise, panic reactions and retirement from the objectal world. Otherness triggers psychic pain and vacillation of symbiotic bounds. Thus the avoidance of, and retirement from, reality and the recourse to delusional thinking, especially when attempts to controlling with a rigid system are failing and deceiving. Threats of intrusion and loss of control are experienced as a threat of fragmentation and dissolution of the psyche. Far less threatening to the subject's internal balance is the policy of rigidly maintaining sameness and cuddling inside the object. PMID:7689733

  20. Microbiome change by symbiotic invasion in lichens

    NASA Astrophysics Data System (ADS)

    Maier, Stefanie; Wedin, Mats; Fernandez-Brime, Samantha; Cronholm, Bodil; Westberg, Martin; Weber, Bettina; Grube, Martin

    2016-04-01

    Alphaproteobacteria with a concomitant increase in Betaproteobacteria. Armatimonadia, Spartobacteria and Acidobacteria also decreased during the infection of Cladonia by Diploschistes. The lichens differed in photobiont specificity. C. symphycarpa was associated with the same algal species at all sites, but D. muscorum had a flexible strategy with different photobiont combinations at each site. This symbiotic invasion system suggests that partners can be reorganized in BSC and selected for maintaining potential roles rather than depending on particular species.

  1. PSR switchyard kicker system improvements

    SciTech Connect

    Hardek, T.W.

    1991-01-01

    A switchyard kicker system which allows time sharing of beam between the Los Alamos WNR/LANSCE complex and other LAMPF users was redesigned as part of the Proton Storage Ring addition. The system consists of two pulsers providing 1750-ampere, 1-msec pulses to a pair of 1 meter long ferrite magnets. The system was designed to operate at 24-Hz maximum repetition rate. In 1986 a modification was made to the equipment to allow operation at 40 Hz. While the system operated reliably this way some difficulties were observed. A desire on the part of the users to operate the system at 60 Hz coupled with a major system failure led to design changes to load resistors, drive cables, charging system, and cooling system. These changes are described along with an analysis of the difficulties encountered with the original hardware. 3 refs., 6 figs.

  2. SU Lyncis, a hard X-ray bright M giant: clues point to a large hidden population of symbiotic stars

    NASA Astrophysics Data System (ADS)

    Mukai, K.; Luna, G. J. M.; Cusumano, G.; Segreto, A.; Munari, U.; Sokoloski, J. L.; Lucy, A. B.; Nelson, T.; Nuñez, N. E.

    2016-09-01

    Symbiotic star surveys have traditionally relied almost exclusively on low resolution optical spectroscopy. However, we can obtain a more reliable estimate of their total Galactic population by using all available signatures of the symbiotic phenomenon. Here we report the discovery of a hard X-ray source, 4PBC J0642.9+5528, in the Swift hard X-ray all-sky survey, and identify it with a poorly studied red giant, SU Lyn, using pointed Swift observations and ground-based optical spectroscopy. The X-ray spectrum, the optical to UV spectrum, and the rapid UV variability of SU Lyn are all consistent with our interpretation that it is a symbiotic star containing an accreting white dwarf. The symbiotic nature of SU Lyn went unnoticed until now, because it does not exhibit emission lines strong enough to be obvious in low resolution spectra. We argue that symbiotic stars without shell-burning have weak emission lines, and that the current lists of symbiotic stars are biased in favour of shell-burning systems. We conclude that the true population of symbiotic stars has been underestimated, potentially by a large factor.

  3. Response properties of self-improving systems

    NASA Astrophysics Data System (ADS)

    Krakovsky, Andrey

    2016-04-01

    We observe that a sustained positivity (or negativity) of a system's second-order response will result in a directional change of the system's characteristics under the corresponding random exposure. We identify these changes with improvement (or decline) in the state of a system and introduce the concept of self-improving systems as systems which characteristics can sustainably improve under a random exposure. The resulting framework is of a general phenomenological nature and can be applied to complex systems across different areas of knowledge.

  4. Response properties of self-improving systems.

    PubMed

    Krakovsky, Andrey

    2016-04-01

    We observe that a sustained positivity (or negativity) of a system's second-order response will result in a directional change of the system's characteristics under the corresponding random exposure. We identify these changes with improvement (or decline) in the state of a system and introduce the concept of self-improving systems as systems which characteristics can sustainably improve under a random exposure. The resulting framework is of a general phenomenological nature and can be applied to complex systems across different areas of knowledge. PMID:27059562

  5. Searching for New Yellow Symbiotic Stars: Positive Identification of StHα63

    NASA Astrophysics Data System (ADS)

    Baella, N. O.; Pereira, C. B.; Miranda, L. F.; Alvarez-Candal, A.

    2016-04-01

    Yellow symbiotic stars are useful targets for probing whether mass transfer has happened in their binary systems. However, the number of known yellow symbiotic stars is very scarce. We report spectroscopic observations of five candidate yellow symbiotic stars that were selected by their positions in the 2MASS (J - H) versus (H - Ks) diagram and which were included in some emission-line catalogs. Among the five candidates, only StHα63 is identified as a new yellow symbiotic star because of its spectrum and its position in the [TiO]1-[TiO]2 diagram, which indicates a K4-K6 spectral type. In addition, the derived electron density (˜108.4 cm-3) and several emission-line intensity ratios provide further support for that classification. The other four candidates are rejected as symbiotic stars because three of them actually do not show emission lines and the fourth one only Balmer emission lines. We also found that the WISE W3-W4 index clearly separates normal K-giants from yellow symbiotic stars and therefore can be used as an additional tool for selecting candidate yellow symbiotic stars. Based on observations collected at the Centro Astronómico Hispano-Alemán, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie (Heidelberg) and the Instituto de Astrofísica de Andalucía (CSIC), and at the 4.1 m telescope at Cerro Pachón Observatory, Chile.

  6. A multi-frequency study of symbiotic stars. I - Near-simultaneous optical and radio observations

    NASA Astrophysics Data System (ADS)

    Ivison, R. J.; Bode, M. F.; Roberts, J. A.; Meaburn, J.; Davis, R. J.; Nelson, R. F.; Spencer, R. E.

    1991-03-01

    The relationship between optical line flux and 5 GHz radio flux is investigated for a sample of 17 northern sky symbiotic stars. Data were obtained near-simultaneously with the Manchester Echelle Spectrograph mounted on the Issac Newton Telescope, La Palma and the Broad Band Interferometer at Jodrell Bank. Color excesses, calculated from Balmer hydrogen line fluxes assuming Case B recombination ratios, are compared with other reddening estimates and also combined with extinction maps to provide improved distance estimates. Optical line fluxes are used in combination with radio fluxes to estimate physical parameters of these objects, including mass-loss rates. The suggestion that the ionized regions of D-type symbiotics are much more extensive than those in S-type is confirmed. This in turn strengthens the hypothesis that S-type symbiotics are more likely to be undergoing Roche-lobe overflow than their D-type counterparts.

  7. Overview of the observations of symbiotic stars

    NASA Technical Reports Server (NTRS)

    Viotti, Roberto

    1993-01-01

    The term Symbiotic stars commonly denotes variable stars whose optical spectra simultaneously present a cool absorption spectrum (typically TiO absorption bands) and emission lines of high ionization energy. This term is now used for the category of variable stars with composite spectrum. The main spectral features of these objects are: (1) the presence of the red continuum typical of a cool star, (2) the rich emission line spectrum, and (3) the UV excess, frequently with the Balmer continuum in emission. In addition to the peculiar spectrum, the very irregular photometric and spectroscopic variability is the major feature of the symbiotic stars. Moreover, the light curve is basic to identify the different phases of activity in a symbiotic star. The physical mechanisms that cause the symbiotic phenomenon and its variety are the focus of this paper. An astronomical phenomenon characterized by a composite stellar spectrum with two apparently conflicting features, and large variability has been observed. Our research set out to find the origin of this behavior and, in particular, to identify and measure the physical mechanism(s) responsible for the observed phenomena.

  8. Genomic and Cellular Complexity from Symbiotic Simplicity

    PubMed Central

    Bordenstein, Seth R.

    2015-01-01

    The more that biologists study symbiotic microorganisms and their vast influence on animals, the more nature’s networkism unfolds in a continuum at different biological scales. In this issue, Van Leuven et al. illuminate how a stable and longstanding animal-microbe mutualism increased its intergenomic network without gaining any new genomes. PMID:25215482

  9. Rhizobial peptidase HrrP cleaves host-encoded signaling peptides and mediates symbiotic compatibility

    PubMed Central

    Price, Paul A.; Tanner, Houston R.; Dillon, Brett A.; Shabab, Mohammed; Walker, Graham C.; Griffitts, Joel S.

    2015-01-01

    Legume–rhizobium pairs are often observed that produce symbiotic root nodules but fail to fix nitrogen. Using the Sinorhizobium meliloti and Medicago truncatula symbiotic system, we previously described several naturally occurring accessory plasmids capable of disrupting the late stages of nodule development while enhancing bacterial proliferation within the nodule. We report here that host range restriction peptidase (hrrP), a gene found on one of these plasmids, is capable of conferring both these properties. hrrP encodes an M16A family metallopeptidase whose catalytic activity is required for these symbiotic effects. The ability of hrrP to suppress nitrogen fixation is conditioned upon the genotypes of both the host plant and the hrrP-expressing rhizobial strain, suggesting its involvement in symbiotic communication. Purified HrrP protein is capable of degrading a range of nodule-specific cysteine-rich (NCR) peptides encoded by M. truncatula. NCR peptides are crucial signals used by M. truncatula for inducing and maintaining rhizobial differentiation within nodules, as demonstrated in the accompanying article [Horváth B, et al. (2015) Proc Natl Acad Sci USA, 10.1073/pnas.1500777112]. The expression pattern of hrrP and its effects on rhizobial morphology are consistent with the NCR peptide cleavage model. This work points to a symbiotic dialogue involving a complex ensemble of host-derived signaling peptides and bacterial modifier enzymes capable of adjusting signal strength, sometimes with exploitative outcomes. PMID:26401024

  10. Plant-Associated Symbiotic Burkholderia Species Lack Hallmark Strategies Required in Mammalian Pathogenesis

    PubMed Central

    Fong, Stephanie; Yerrapragada, Shailaja; Estrada-de los Santos, Paulina; Yang, Paul; Song, Nannie; Kano, Stephanie; de Faria, Sergio M.; Dakora, Felix D.; Weinstock, George; Hirsch, Ann M.

    2014-01-01

    Burkholderia is a diverse and dynamic genus, containing pathogenic species as well as species that form complex interactions with plants. Pathogenic strains, such as B. pseudomallei and B. mallei, can cause serious disease in mammals, while other Burkholderia strains are opportunistic pathogens, infecting humans or animals with a compromised immune system. Although some of the opportunistic Burkholderia pathogens are known to promote plant growth and even fix nitrogen, the risk of infection to infants, the elderly, and people who are immunocompromised has not only resulted in a restriction on their use, but has also limited the application of non-pathogenic, symbiotic species, several of which nodulate legume roots or have positive effects on plant growth. However, recent phylogenetic analyses have demonstrated that Burkholderia species separate into distinct lineages, suggesting the possibility for safe use of certain symbiotic species in agricultural contexts. A number of environmental strains that promote plant growth or degrade xenobiotics are also included in the symbiotic lineage. Many of these species have the potential to enhance agriculture in areas where fertilizers are not readily available and may serve in the future as inocula for crops growing in soils impacted by climate change. Here we address the pathogenic potential of several of the symbiotic Burkholderia strains using bioinformatics and functional tests. A series of infection experiments using Caenorhabditis elegans and HeLa cells, as well as genomic characterization of pathogenic loci, show that the risk of opportunistic infection by symbiotic strains such as B. tuberum is extremely low. PMID:24416172

  11. Symbiotic variable V4018 Sgr in outburst

    NASA Astrophysics Data System (ADS)

    Elizabeth O. Waagen

    2012-09-01

    The symbiotic variable V4018 Sgr is undergoing an outburst, according to observations reported to the AAVSO and confirmed by spectroscopy by Ulisse Munari et al. Prompted by an observation and comment from John Bortle (Stormville, NY) (16 June 2012, visual magnitude 12.2) about a possible outburst, Steven O'Connor (St. George's, Bermuda) obtained an observation (10 August 2012, 11.44V) that confirmed V4018 Sgr was bright. His subsequent BVRI observations in September and visual observations by Bortle and Andrew Pearce (Nedlands, Western Australia) show the system brightening and at V magnitude 11.07 as of 2012 Sep. 17.091 UT. Ulisse Munari (INAF Astr. Obs. Padua, Italy) and colleagues Paolo Valisa and Sergio Dallaporta (ANS Collaboration), after being informed by the AAVSO of the bright state of V4018 Sgr, carried out spectroscopy. Munari writes: "A low resolution, absolutely fluxed 4000-8650 Ang spectrum of V4018 Sgr was obtained on Sept 13.90 UT with the 0.6m telescope ! of the Schiaparelli Observatory in Varese (Italy). It shows the spectrum of the M giant overwhelmed by a blue continuum up to 6000 Ang, and all high ionization emission lines typical of quiescence are gone, leaving only hydrogen Balmer and weak HeI lines in emission. The spectrum looks like a template one for a symbiotic star in outburst. CCD photometry was obtained on Sept 13.79 UT and provides V=11.027 ± 0.002, B-V=+0.621 ± 0.003. The B-V color is appreciably bluer and the V magnitude much brighter than typical in quiescence (on average V=13.3, B-V=+1.09; Henden and Munari 2008, Baltic Astronomy 17, 293), and support the idea V4018 Sgr is undergoing an outburst." According to Munari, the last bright outburst of V4018 Sgr was underway in June 1990. Observations in the AAVSO International Database from Albert Jones (Nelson, New Zealand) beginning in May 1992 show the variable at visual magnitude 11.0, with fluctuations between 10.5 and 11.9 through October 1995. Numerous ! other observers

  12. Quality improvement in population health systems.

    PubMed

    Inkelas, Moira; McPherson, Marianne E

    2015-12-01

    Quality improvement methods have achieved large sustainable changes in health care quality and health outcomes. Transforming health care into a population health system requires methods for innovation and improvement that can work across professions and sectors. It may be possible to replicate improvement successes in healthcare settings within and across the broader systems of social, educational, and other human services that influence health outcomes in communities. Improvement methods could translate the rhetoric of collaboration, integration and alignment into practice across the fragmented health and human service sectors in the U.S. PMID:26699349

  13. Hydrodynamical simulations of the jet in the symbiotic star MWC 560. I. Structure, emission and synthetic absorption line profiles

    NASA Astrophysics Data System (ADS)

    Stute, M.; Camenzind, M.; Schmid, H. M.

    2005-01-01

    We performed hydrodynamical simulations with and without radiative cooling of jet models with parameters representative of the symbiotic system MWC 560. For symbiotic systems we have to perform jet simulations of a pulsed underdense jet in a high density ambient medium. We present the jet structure resulting from our simulations and calculate emission plots which account for expected radiative processes. In addition, our calculations provide expansion velocities for the jet bow shock, the density and temperature structure in the jet, and the propagation and evolution of the jet pulses. In MWC 560 the jet axis is parallel to the line of sight so that the outflowing jet gas can be seen as blue shifted, variable absorption lines in the continuum of the underlying jet source. Based on our simulations we calculate and discuss synthetic absorption profiles. Based on a detailed comparison between model spectra and observations we discuss our hydrodynamical calculations for a pulsed jet in MWC 560 and suggest improvements for future models. Figures \\ref{skizze}, \\ref{modi_det}, \\ref{slice_cool_p}, \\ref{NV_3.0_synch}, \\ref{modelicool_greyscale}, \\ref{line_rem}-\\ref{line_dv} and \\ref{line_zmax} are only available in electronic form at http://www.edpsciences.org

  14. Symbiotic options for the conquest of land.

    PubMed

    Field, Katie J; Pressel, Silvia; Duckett, Jeffrey G; Rimington, William R; Bidartondo, Martin I

    2015-08-01

    The domination of the landmasses of Earth by plants starting during the Ordovician Period drastically altered the development of the biosphere and the composition of the atmosphere, with far-reaching consequences for all life ever since. It is widely thought that symbiotic soil fungi facilitated the colonization of the terrestrial environment by plants. However, recent discoveries in molecular ecology, physiology, cytology, and paleontology have brought into question the hitherto-assumed identity and biology of the fungi engaged in symbiosis with the earliest-diverging lineages of extant land plants. Here, we reconsider the existing paradigm and show that the symbiotic options available to the first plants emerging onto the land were more varied than previously thought. PMID:26111583

  15. Molecular Determinants of a Symbiotic Chronic Infection

    PubMed Central

    Gibson, Katherine E.; Kobayashi, Hajime

    2009-01-01

    Rhizobial bacteria colonize legume roots for the purpose of biological nitrogen fixation. A complex series of events, coordinated by host and bacterial signal molecules, underlie the development of this symbiotic interaction. Rhizobia elicit de novo formation of a novel root organ within which they establish a chronic intracellular infection. Legumes permit rhizobia to invade these root tissues while exerting control over the infection process. Once rhizobia gain intracellular access to their host, legumes also strongly influence the process of bacterial differentiation that is required for nitrogen fixation. Even so, symbiotic rhizobia play an active role in promoting their goal of host invasion and chronic persistence by producing a variety of signal molecules that elicit changes in host gene expression. In particular, rhizobia appear to advocate for their access to the host by producing a variety of signal molecules capable of suppressing a general pathogen defense response. PMID:18983260

  16. Isolation of symbiotic dinoflagellates by centrifugal elutriation

    SciTech Connect

    Bird, A.E.; Quinn, R.J.

    1986-01-01

    Centrifugal elutriation, a method combining centripetal liquid flow with centrifugal force, has been used to isolate symbiotic dinoflagellates from a cnidarian host. The elutriated cells were shown to be viable by photosynthetic incorporation of /sup 14/CO/sub 2/ and low release of photosynthetic products into the incubation medium. The level of contamination by clinging debris was low and by host solids was negligible.

  17. An improved instantaneous laser Doppler velocity system

    NASA Astrophysics Data System (ADS)

    Desio, Charles V.; Olcmen, Semih; Schinetsky, Philip

    2016-02-01

    In this paper, improvements made on a single velocity component instantaneous laser Doppler velocimetry (ILDV) system are detailed. The ILDV system developed in this research effort is capable of measuring a single velocity component at a rate as high as two megahertz. The current system accounts for the effects of the laser intensity variation on the measured velocity and eliminates the use of a Pockels cell used in previous ILDV systems. The system developed in the current effort was tested using compressible, subsonic jet flows. The ILDV system developed would be most beneficial where a high data capture rate is needed such as in shock tubes, and high-speed wind tunnels.

  18. A simple framework for complex system improvement.

    PubMed

    Kraft, Sally; Carayon, Pascale; Weiss, Jennifer; Pandhi, Nancy

    2015-05-01

    The need to rapidly improve health care value is unquestioned, but the means to accomplish this task is unknown. Improving performance at the level of the health care organization frequently involves multiple interventions, which must be coordinated and sequenced to fit the specific context. Those responsible for achieving large-scale improvements are challenged by the lack of a framework to describe and organize improvement strategies. Drawing from the fields of health services, industrial engineering, and organizational behavior, a simple framework was developed and has been used to guide and evaluate improvement initiatives at an academic health center. The authors anticipate that this framework will be helpful for health system leaders responsible for improving health care quality. PMID:24723664

  19. Improving Ohio's Education Management Information System (EMIS).

    ERIC Educational Resources Information Center

    Ohio State Legislative Office of Education Oversight, Columbus.

    Due to legislative mandate, the Ohio Department of Education (ODE) was required to develop a system (the Education Management Information System) that would increase the amount of information available to state-level policy makers and the public. Some recommendations for improving the function of EMIS are offered in this report. The text provides…

  20. Improving College System Pathways: Project Highlights Reports

    ERIC Educational Resources Information Center

    Colleges Ontario, 2008

    2008-01-01

    In 2006, Ontario's colleges received funding from the Ministry of Training, Colleges and Universities for the Improving College System Pathways Project. The project goals were to significantly increase educational pathways within and between colleges by developing a clearer understanding of student mobility within the system; to identify the scope…

  1. Non-symbiotic Bradyrhizobium ecotypes dominate North American forest soils.

    PubMed

    VanInsberghe, David; Maas, Kendra R; Cardenas, Erick; Strachan, Cameron R; Hallam, Steven J; Mohn, William W

    2015-11-01

    The genus Bradyrhizobium has served as a model system for studying host-microbe symbiotic interactions and nitrogen fixation due to its importance in agricultural productivity and global nitrogen cycling. In this study, we identify a bacterial group affiliated with this genus that dominates the microbial communities of coniferous forest soils from six distinct ecozones across North America. Representative isolates from this group were obtained and characterized. Using quantitative population genomics, we show that forest soil populations of Bradyrhizobium represent ecotypes incapable of nodulating legume root hairs or fixing atmospheric nitrogen. Instead, these populations appear to be free living and have a greater potential for metabolizing aromatic carbon sources than their close symbiotic relatives. In addition, we identify fine-scaled differentiation between populations inhabiting neighboring soil layers that illustrate how diversity within Bradyrhizobium is structured by habitat similarity. These findings reconcile incongruent observations about this widely studied and important group of bacteria and highlight the value of ecological context to interpretations of microbial diversity and taxonomy. These results further suggest that the influence of this genus likely extends well beyond facilitating agriculture, especially as forest ecosystems are large and integral components of the biosphere. In addition, this study demonstrates how focusing research on economically important microorganisms can bias our understanding of the natural world. PMID:25909973

  2. Extensive Differences in Gene Expression Between Symbiotic and Aposymbiotic Cnidarians

    PubMed Central

    Lehnert, Erik M.; Mouchka, Morgan E.; Burriesci, Matthew S.; Gallo, Natalya D.; Schwarz, Jodi A.; Pringle, John R.

    2013-01-01

    Coral reefs provide habitats for a disproportionate number of marine species relative to the small area of the oceans that they occupy. The mutualism between the cnidarian animal hosts and their intracellular dinoflagellate symbionts provides the nutritional foundation for coral growth and formation of reef structures, because algal photosynthesis can provide >90% of the total energy of the host. Disruption of this symbiosis (“coral bleaching”) is occurring on a large scale due primarily to anthropogenic factors and poses a major threat to the future of coral reefs. Despite the importance of this symbiosis, the cellular mechanisms involved in its establishment, maintenance, and breakdown remain largely unknown. We report our continued development of genomic tools to study these mechanisms in Aiptasia, a small sea anemone with great promise as a model system for studies of cnidarian–dinoflagellate symbiosis. Specifically, we have generated de novo assemblies of the transcriptomes of both a clonal line of symbiotic anemones and their endogenous dinoflagellate symbionts. We then compared transcript abundances in animals with and without dinoflagellates. This analysis identified >900 differentially expressed genes and allowed us to generate testable hypotheses about the cellular functions affected by symbiosis establishment. The differentially regulated transcripts include >60 encoding proteins that may play roles in transporting various nutrients between the symbiotic partners; many more encoding proteins functioning in several metabolic pathways, providing clues regarding how the transported nutrients may be used by the partners; and several encoding proteins that may be involved in host recognition and tolerance of the dinoflagellate. PMID:24368779

  3. Symbiotic crabs maintain coral health by clearing sediments

    NASA Astrophysics Data System (ADS)

    Stewart, Hannah L.; Holbrook, Sally J.; Schmitt, Russell J.; Brooks, Andrew J.

    2006-11-01

    Stony corals are the foundation of coral reef ecosystems and form associations with other reef species. Many of these associations may be ecologically important and play a role in maintaining the health and diversity of reef systems, rendering it critical to understand the influence of symbiotic organisms in mediating responses to perturbation. This study demonstrates the importance of an association with trapeziid crabs in reducing adverse effects of sediments deposited on corals. In a field experiment, mortality rates of two species of branching corals were significantly lowered by the presence of crabs. All outplanted corals with crabs survived whereas 45-80% of corals without crabs died within a month. For surviving corals that lacked crabs, growth was slower and tissue bleaching and sediment load were higher. Laboratory experiments revealed that corals with crabs shed substantially more of the sediments deposited on coral surfaces, but also that crabs were most effective at removing grain sizes that were most damaging to coral tissues. The mechanism underlying this symbiotic relationship has not been recognized previously, and its role in maintaining coral health is likely to become even more critical as reefs worldwide experience increasing sedimentation.

  4. Improvements to information management systems simulator

    NASA Technical Reports Server (NTRS)

    Bilek, R. W.

    1972-01-01

    The performance of personnel in the augmentation and improvement of the interactive IMSIM information management simulation model is summarized. With this augmented model, NASA now has even greater capabilities for the simulation of computer system configurations, data processing loads imposed on these configurations, and executive software to control system operations. Through these simulations, NASA has an extremely cost effective capability for the design and analysis of computer-based data management systems.

  5. Improved Interactive Medical-Imaging System

    NASA Technical Reports Server (NTRS)

    Ross, Muriel D.; Twombly, Ian A.; Senger, Steven

    2003-01-01

    An improved computational-simulation system for interactive medical imaging has been invented. The system displays high-resolution, three-dimensional-appearing images of anatomical objects based on data acquired by such techniques as computed tomography (CT) and magnetic-resonance imaging (MRI). The system enables users to manipulate the data to obtain a variety of views for example, to display cross sections in specified planes or to rotate images about specified axes. Relative to prior such systems, this system offers enhanced capabilities for synthesizing images of surgical cuts and for collaboration by users at multiple, remote computing sites.

  6. Improved MFCC algorithm in speaker recognition system

    NASA Astrophysics Data System (ADS)

    Shi, Yibo; Wang, Li

    2011-10-01

    In speaker recognition systems, one of the key feature parameters is MFCC, which can be used for speaker recognition. So, how to extract MFCC parameter in speech signals more exactly and efficiently, decides the performance of the system. Theoretically, MFCC parameters are used to describe the spectrum envelope of the vocal tract characteristics and often ignore the impacts of fundamental frequency. But in practice, MFCC can be influenced by fundamental frequency which can cause palpable performance reduction. So, smoothing MFCC (SMFCC), which based on smoothing short-term spectral amplitude envelope, has been proposed to improve MFCC algorithm. Experimental results show that improved MFCC parameters---SMFCC can degrade the bad influences of fundamental frequency effectively and upgrade the performances of speaker recognition system. Especially for female speakers, who have higher fundamental frequency, the recognition rate improves more significantly.

  7. Improved All-Terrain Suspension System

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B.

    1994-01-01

    Redesigned suspension system for all-terrain vehicle exhibits enhanced ability to negotiate sand and rocks. Improved six-wheel suspension system includes only two links on each side. Bogie tends to pull rear wheels with it as it climbs. Designed for rover vehicle for exploration of Mars, also has potential application in off-road vehicles, military scout vehicles, robotic emergency vehicles, and toys. Predecessors of suspension system described in "Articulated Suspension Without Springs" (NPO-17354), "Four-Wheel Vehicle Suspension System" (NPO-17407), and "High-Clearance Six-Wheel Suspension" (NPO-17821).

  8. Compensator improvement for multivariable control systems

    NASA Technical Reports Server (NTRS)

    Mitchell, J. R.; Mcdaniel, W. L., Jr.; Gresham, L. L.

    1977-01-01

    A theory and the associated numerical technique are developed for an iterative design improvement of the compensation for linear, time-invariant control systems with multiple inputs and multiple outputs. A strict constraint algorithm is used in obtaining a solution of the specified constraints of the control design. The result of the research effort is the multiple input, multiple output Compensator Improvement Program (CIP). The objective of the Compensator Improvement Program is to modify in an iterative manner the free parameters of the dynamic compensation matrix so that the system satisfies frequency domain specifications. In this exposition, the underlying principles of the multivariable CIP algorithm are presented and the practical utility of the program is illustrated with space vehicle related examples.

  9. New camera tube improves ultrasonic inspection system

    NASA Technical Reports Server (NTRS)

    Berger, H.; Collis, W. J.; Jacobs, J. E.

    1968-01-01

    Electron multiplier, incorporated into the camera tube of an ultrasonic imaging system, improves resolution, effectively shields low level circuits, and provides a high level signal input to the television camera. It is effective for inspection of metallic materials for bonds, voids, and homogeneity.

  10. A challenging future for improved photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Allen, Douglas M.

    The expansion of space requirements creates opportunities and priorities for power production, thus driving the development of innovative technologies. Key requirements for improving photovoltaics are outlined including cell efficiency, specific power, packaging, reliability, and affordability issues. The competition faced by photovoltaic cells is discussed with specific reference to solar dynamics and nuclear radioisotope thermal generator systems.

  11. State Systems Improvement Self-Assessment

    ERIC Educational Resources Information Center

    Mid-South Regional Resource Center (MSRRC), 2008

    2008-01-01

    This document was developed by the Mid-South Regional Resource Center (MSRRC) and is designed to be used as an assessment of State systems by State Part B and Part C staff and their stakeholders. It provides a detailed process for State Education Agencies (SEA) and Lead Agencies (LA) to follow that will guide improvement efforts relative to the…

  12. Improving reservoir conformance using gelled polymer systems

    SciTech Connect

    Green, D.W.; Willhite, G.P.

    1993-04-09

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems - an aqueous polysaccharide (KUSPI) system that gels as a function of pH, the chromium-based system where polyacrylamide and xanthan are crosslinked by CR(III) and an organic crosslinked system. Development of the KUSPI system and evaluation and identification of a suitable organic crosslinked system will be done. The laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Accomplishments for this period are presented for the following tasks: development and selection of gelled polymer systems, physical and chemical characterization of gel systems; and mathematical modeling of gel systems.

  13. Improving reservoir conformance using gelled polymer systems

    SciTech Connect

    Green, D.W.; Willhite, P.G.

    1992-12-25

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems -- an aqueous polysaccharide (KUSP1) system that gels as a function of pH, the chromium-based system where polyacrylamide and xanthan are crosslinked by Cr(III) and an organic crosslinked system. Development of the KUSP1 system and evaluation and, identification of the organic crosslinked system will be conducted. The laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Progress report are presented for the following tasks: Development and selection of gelled polymer systems; physical and chemical characterization of gel systems; and mathematical modelling of gel systems.

  14. Progress in photovoltaic system and component improvements

    SciTech Connect

    Thomas, H.P.; Kroposki, B.; McNutt, P.; Witt, C.E.; Bower, W.; Bonn, R.; Hund, T.D.

    1998-07-01

    The Photovoltaic Manufacturing Technology (PVMaT) project is a partnership between the US government (through the US Department of Energy [DOE]) and the PV industry. Part of its purpose is to conduct manufacturing technology research and development to address the issues and opportunities identified by industry to advance photovoltaic (PV) systems and components. The project was initiated in 1990 and has been conducted in several phases to support the evolution of PV industrial manufacturing technology. Early phases of the project stressed PV module manufacturing. Starting with Phase 4A and continuing in Phase 5A, the goals were broadened to include improvement of component efficiency, energy storage and manufacturing and system or component integration to bring together all elements for a PV product. This paper summarizes PV manufacturers` accomplishments in components, system integration, and alternative manufacturing methods. Their approaches have resulted in improved hardware and PV system performance, better system compatibility, and new system capabilities. Results include new products such as Underwriters Laboratories (UL)-listed AC PV modules, modular inverters, and advanced inverter designs that use readily available and standard components. Work planned in Phase 5A1 includes integrated residential and commercial roof-top systems, PV systems with energy storage, and 300-Wac to 4-kWac inverters.

  15. Profile disparity of Raman-scattered O VI in symbiotic stars

    NASA Astrophysics Data System (ADS)

    Lee, Hee-Won

    2016-07-01

    Symbiotic stars are wide binary systems consisting of a hot compact star (usually a white dwarf) and a mass losing giant. Symbiotic activities are believed to occur through gravitational capture of a fraction of the slow stellar wind from the giant. Raman scattered features of O VI resonance doublet 1032 and 1038 appearing at around 6825 Å and 7082 Å are a unique spectroscopic diagnostic tool to probe the mass transfer process in symbiotic stars. The Raman O VI features often exhibit multiple peak structures and in many cases the blue peak of 7082 features is relatively more suppressed than that of 6825 features. We propose that the disparity of the two profiles is attributed to the local variation of optical depths of O VI, implying that the accretion flow is convergent in the red emission region and divergent in the blue emission region. It is argued in this presentation that Raman scattering by atomic hydrogen is a natural mirror to provide an edge-on view of the accretion disk and a lateral view of the bipolar outflow in symbiotic stars. We discuss the spectropolarimetric implications of this interpretation.

  16. Genomic resources for identification of the minimal N2 -fixing symbiotic genome.

    PubMed

    diCenzo, George C; Zamani, Maryam; Milunovic, Branislava; Finan, Turlough M

    2016-09-01

    The lack of an appropriate genomic platform has precluded the use of gain-of-function approaches to study the rhizobium-legume symbiosis, preventing the establishment of the genes necessary and sufficient for symbiotic nitrogen fixation (SNF) and potentially hindering synthetic biology approaches aimed at engineering this process. Here, we describe the development of an appropriate system by reverse engineering Sinorhizobium meliloti. Using a novel in vivo cloning procedure, the engA-tRNA-rmlC (ETR) region, essential for cell viability and symbiosis, was transferred from Sinorhizobium fredii to the ancestral location on the S. meliloti chromosome, rendering the ETR region on pSymB redundant. A derivative of this strain lacking both the large symbiotic replicons (pSymA and pSymB) was constructed. Transfer of pSymA and pSymB back into this strain restored symbiotic capabilities with alfalfa. To delineate the location of the single-copy genes essential for SNF on these replicons, we screened a S. meliloti deletion library, representing > 95% of the 2900 genes of the symbiotic replicons, for their phenotypes with alfalfa. Only four loci, accounting for < 12% of pSymA and pSymB, were essential for SNF. These regions will serve as our preliminary target of the minimal set of horizontally acquired genes necessary and sufficient for SNF. PMID:26768651

  17. Improving governance to improve oral health: addressing care delivery systems.

    PubMed

    Batchelor, Paul

    2012-09-01

    The evolving role of the state in the provision of health care has seen the adoption of new management philosophies to ensure that goals set for the system are reached. In particular, the term New Public Management (NPM) has tended to dominate reforms to help address perceived shortcomings in public sector services. NPM is based on the use of freemarket type arrangements as a mechanism to solve problems, the control of which provides new challenges. One particular challenge that has arisen from the combination of NPM with the large number of agencies involved in care provision is that of addressing the issues arising from the improved understanding of the determinants of health. This has led to the evolution of differing care arrangements across differing sectors at all levels. If resources are to be used as intended, the control of delivery systems to oversee their use must exist. The overarching term for such activity is â governance. This paper provides an overview of the issues that arise for addressing governance of oral health care and the subsequent challenges that face those responsible for ensuring compliance. PMID:22976573

  18. Improved Photon-Emission-Microscope System

    NASA Technical Reports Server (NTRS)

    Vu, Duc

    2006-01-01

    An improved photon-emission-microscope (PEM) instrumentation system has been developed for use in diagnosing failure conditions in semiconductor devices, including complex integrated circuits. This system is designed primarily to image areas that emit photons, at wavelengths from 400 to 1,100 nm, associated with device failures caused by leakage of electric current through SiO2 and other dielectric materials used in multilayer semiconductor structures. In addition, the system is sensitive enough to image areas that emit photons during normal operation.

  19. Comparative proteomics of symbiotic and aposymbiotic juvenile soft corals.

    PubMed

    Barneah, O; Benayahu, Y; Weis, V M

    2006-01-01

    The symbiotic association between corals and photosynthetic unicellular algae is of great importance in coral reef ecosystems. The study of symbiotic relationships is multidisciplinary and involves research in phylogeny, physiology, biochemistry, and ecology. An intriguing phase in each symbiotic relationship is its initiation, in which the partners interact for the first time. The examination of this phase in coral-algae symbiosis from a molecular point of view is still at an early stage. In the present study we used 2-dimensional polyacrylamide gel electrophoresis to compare patterns of proteins synthesized in symbiotic and aposymbiotic primary polyps of the Red Sea soft coral Heteroxenia fuscescens. This is the first work to search for symbiosis-specific proteins during the natural onset of symbiosis in early host ontogeny. The protein profiles reveal changes in the host soft coral proteome through development, but surprisingly virtually no changes in the host proteome as a function of symbiotic state. PMID:16059755

  20. On the nature of the symbiotic star BF Cygni

    NASA Technical Reports Server (NTRS)

    Mikolajewska, J.; Mikolajewski, M.; Kenyon, S. J.

    1989-01-01

    Optical and ultraviolet spectroscopy of the symbiotic binary BF Cyg obtained during 1979-1988 is discussed. This system consists of a low-mass M5 giant filling about 50 percent of its tidal volume and a hot, luminous compact object similar to the central star of a planetary nebula. The binary is embedded in an asymmetric nebula which includes a small, high-density region and an extended region of lower density. The larger nebula is formed by a slow wind ejected by the cool component and ionized by the hot star, while the more compact nebula is material expelled by the hot component in the form of a bipolar wind. The analysis indicates that disk accretion is essential to maintain the nuclear burning shell of the hot star.

  1. SYMBIOTIC STAR BLOWS BUBBLES INTO SPACE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A tempestuous relationship between an unlikely pair of stars may have created an oddly shaped, gaseous nebula that resembles an hourglass nestled within an hourglass. Images taken with Earth-based telescopes have shown the larger, hourglass-shaped nebula. But this picture, taken with NASA's Hubble Space Telescope, reveals a small, bright nebula embedded in the center of the larger one (close-up of nebula in inset). Astronomers have dubbed the entire nebula the 'Southern Crab Nebula' (He2-104), because, from ground-based telescopes, it looks like the body and legs of a crab. The nebula is several light-years long. The possible creators of these shapes cannot be seen at all in this Wide Field and Planetary Camera 2 image. It's a pair of aging stars buried in the glow of the tiny, central nebula. One of them is a red giant, a bloated star that is exhausting its nuclear fuel and is shedding its outer layers in a powerful stellar wind. Its companion is a hot, white dwarf, a stellar zombie of a burned-out star. This odd duo of a red giant and a white dwarf is called a symbiotic system. The red giant is also a Mira Variable, a pulsating red giant, that is far away from its partner. It could take as much as 100 years for the two to orbit around each other. Astronomers speculate that the interaction between these two stars may have sparked episodic outbursts of material, creating the gaseous bubbles that form the nebula. They interact by playing a celestial game of 'catch': as the red giant throws off its bulk in a powerful stellar wind, the white dwarf catches some of it. As a result, an accretion disk of material forms around the white dwarf and spirals onto its hot surface. Gas continues to build up on the surface until it sparks an eruption, blowing material into space. This explosive event may have happened twice in the 'Southern Crab.' Astronomers speculate that the hourglass-shaped nebulae represent two separate outbursts that occurred several thousand years apart

  2. Exploring the symbiotic pangenome of the nitrogen-fixing bacterium Sinorhizobium meliloti

    SciTech Connect

    Galardini, Marco; Mengoni, Alessio; Brilli, Matteo; Pini, Francesco; Fioravanti, Antonella; Lucas, Susan; Lapidus, Alla L.; Cheng, Jan-Fang; Goodwin, Lynne A.; Pitluck, Sam; Land, Miriam L; Hauser, Loren John; Woyke, Tanja; Mikhailova, Natalia; Ivanova, N; Daligault, Hajnalka E.; Bruce, David; Detter, J. Chris; Tapia, Roxanne; Han, Cliff; Teshima, Hazuki; Mocali, Stefano; Bazzicalupo, Marco; Biondi, Emanuele

    2011-01-01

    Background: Sinorhizobium meliloti is a model system for the studies of symbiotic nitrogen fixation. An extensive polymorphism at the genetic and phenotypic level is present in natural populations of this species, especially in relation with symbiotic promotion of plant growth. AK83 and BL225C are two nodule-isolated strains with diverse symbiotic phenotypes; BL225C is more efficient in promoting growth of the Medicago sativa plants than strain AK83. In order to investigate the genetic determinants of the phenotypic diversification of S. meliloti strains AK83 and BL225C, we sequenced the complete genomes for these two strains. Results: With sizes of 7.14 Mbp and 6.97 Mbp, respectively, the genomes of AK83 and BL225C are larger than the laboratory strain Rm1021. The core genome of Rm1021, AK83, BL225C strains included 5124 orthologous groups, while the accessory genome was composed by 2700 orthologous groups. While Rm1021 and BL225C have only three replicons (Chromosome, pSymA and pSymB), AK83 has also two plasmids, 260 and 70 Kbp long. We found 65 interesting orthologous groups of genes that were present only in the accessory genome, consequently responsible for phenotypic diversity and putatively involved in plant-bacterium interaction. Notably, the symbiosis inefficient AK83 lacked several genes required for microaerophilic growth inside nodules, while several genes for accessory functions related to competition, plant invasion and bacteroid tropism were identified only in AK83 and BL225C strains. Presence and extent of polymorphism in regulons of transcription factors involved in symbiotic interaction were also analyzed. Our results indicate that regulons are flexible, with a large number of accessory genes, suggesting that regulons polymorphism could also be a key determinant in the variability of symbiotic performances among the analyzed strains.

  3. Rhizobium meliloti Genes Encoding Catabolism of Trigonelline Are Induced under Symbiotic Conditions.

    PubMed

    Boivin, C.; Camut, S.; Malpica, C. A.; Truchet, G.; Rosenberg, C.

    1990-12-01

    Rhizobium meliloti trc genes controlling the catabolism of trigonelline, a plant secondary metabolite often abundant in legumes, are closely linked to nif-nod genes on the symbiotic megaplasmid pSym [Boivin, C., Malpica, C., Rosenberg, C., Denarie, J., Goldman, A., Fleury, V., Maille, M., Message, B., and Tepfer, D. (1989). In Molecular Signals in the Microbe-Plant Symbiotic and Pathogenic Systems. (Berlin: Springer-Verlag), pp. 401-407]. To investigate the role of trigonelline catabolism in the Rhizobium-legume interaction, we studied the regulation of trc gene expression in free-living and in endosymbiotic bacteria using Escherichia coli lacZ as a reporter gene. Experiments performed with free-living bacteria indicated that trc genes were organized in at least four transcription units and that the substrate trigonelline was a specific inducer for three of them. Noninducing trigonelline-related compounds such as betaines appeared to antagonize the inducing effect of trigonelline. None of the general or symbiotic regulatory genes ntrA, dctB/D, or nodD seemed to be involved in trigonelline catabolism. trc fusions exhibiting a low basal and a high induced [beta]-galactosidase activity when present on pSym were used to monitor trc gene expression in alfalfa tissue under symbiotic conditions. Results showed that trc genes are induced during all the symbiotic steps, i.e., in the rhizosphere, infection threads, and bacteroids of alfalfa, suggesting that trigonelline is a nutrient source throughout the Rhizobium-legume association. PMID:12354952

  4. Systems Improved Numerical Fluids Analysis Code

    NASA Technical Reports Server (NTRS)

    Costello, F. A.

    1990-01-01

    Systems Improved Numerical Fluids Analysis Code, SINFAC, consists of additional routines added to April, 1983, version of SINDA. Additional routines provide for mathematical modeling of active heat-transfer loops. Simulates steady-state and pseudo-transient operations of 16 different components of heat-transfer loops, including radiators, evaporators, condensers, mechanical pumps, reservoirs, and many types of valves and fittings. Program contains property-analysis routine used to compute thermodynamic properties of 20 different refrigerants. Source code written in FORTRAN 77.

  5. Fixating on metals: new insights into the role of metals in nodulation and symbiotic nitrogen fixation

    PubMed Central

    González-Guerrero, Manuel; Matthiadis, Anna; Sáez, Áez;ngela; Long, Terri A.

    2014-01-01

    Symbiotic nitrogen fixation is one of the most promising and immediate alternatives to the overuse of polluting nitrogen fertilizers for improving plant nutrition. At the core of this process are a number of metalloproteins that catalyze and provide energy for the conversion of atmospheric nitrogen to ammonia, eliminate free radicals produced by this process, and create the microaerobic conditions required by these reactions. In legumes, metal cofactors are provided to endosymbiotic rhizobia within root nodule cortical cells. However, low metal bioavailability is prevalent in most soils types, resulting in widespread plant metal deficiency and decreased nitrogen fixation capabilities. As a result, renewed efforts have been undertaken to identify the mechanisms governing metal delivery from soil to the rhizobia, and to determine how metals are used in the nodule and how they are recycled once the nodule is no longer functional. This effort is being aided by improved legume molecular biology tools (genome projects, mutant collections, and transformation methods), in addition to state-of-the-art metal visualization systems. PMID:24592271

  6. Improved Airborne System for Sensing Wildfires

    NASA Technical Reports Server (NTRS)

    McKeown, Donald; Richardson, Michael

    2008-01-01

    The Wildfire Airborne Sensing Program (WASP) is engaged in a continuing effort to develop an improved airborne instrumentation system for sensing wildfires. The system could also be used for other aerial-imaging applications, including mapping and military surveillance. Unlike prior airborne fire-detection instrumentation systems, the WASP system would not be based on custom-made multispectral line scanners and associated custom- made complex optomechanical servomechanisms, sensors, readout circuitry, and packaging. Instead, the WASP system would be based on commercial off-the-shelf (COTS) equipment that would include (1) three or four electronic cameras (one for each of three or four wavelength bands) instead of a multispectral line scanner; (2) all associated drive and readout electronics; (3) a camera-pointing gimbal; (4) an inertial measurement unit (IMU) and a Global Positioning System (GPS) receiver for measuring the position, velocity, and orientation of the aircraft; and (5) a data-acquisition subsystem. It would be necessary to custom-develop an integrated sensor optical-bench assembly, a sensor-management subsystem, and software. The use of mostly COTS equipment is intended to reduce development time and cost, relative to those of prior systems.

  7. Improving Systemic Chemotherapy for Bladder Cancer.

    PubMed

    Rose, Tracy L; Milowsky, Matthew I

    2016-05-01

    Systemic chemotherapy is integral to the management of muscle-invasive and metastatic bladder cancer (BCa). Neoadjuvant chemotherapy has been increasingly utilized for muscle-invasive BCa over the past several years, and several options for cisplatin-based regimens have emerged. Adjuvant chemotherapy may be considered for select patients who did not receive neoadjuvant therapy. Systemic chemotherapy added to radiotherapy is a critical component of a bladder-preserving approach and superior to radiotherapy alone. Cisplatin-based chemotherapy has been the mainstay for metastatic BCa for more than three decades. Novel targeted agents are in development fueled by the recent molecular characterization of BCa. Recent trials of immunotherapy have demonstrated the possibility of a less toxic and potentially more effective treatment for metastatic disease. It is an extremely exciting time for BCa research, and much needed improvements in systemic treatment are most certainly on the horizon. PMID:26984414

  8. Improving subsurface hydrology in Earth System Models

    NASA Astrophysics Data System (ADS)

    Volk, J. M.; Clark, M. P.; Swenson, S. C.; Lawrence, D. M.; Tyler, S. W.

    2015-12-01

    Hydrologic processes that govern storage and transport of soil water and groundwater can have strong dynamic relationships with biogeochemical and atmospheric processes. This understanding has lead to a push to improve subsurface hydrologic parametrization in Earth System Models. Here we present results related to improving the implementation of soil moisture distribution, groundwater recharge/discharge, and subsurface drainage in the Community Land Model (CLM) which is the land surface model in the Community Earth System Model. First we identified geo-climatically different locations around the world to develop test cases. For each case we compare the vertical soil moisture distribution from the different implementations of 1D Richards equation, considering the boundary conditions, the treatment of the groundwater sink term, the vertical discretization, and the time stepping schemes. Generally, large errors in the hydrologic mass balance within the soil column occur when there is a large vertical gradient in soil moisture or when there is a shallow water table within a soil column. We then test the sensitivity of the algorithmic parameters that control temporal discretization and error tolerance of the adaptive time-stepping scheme to help optimize its computational efficiency. In addition, we vary the spatial discretization of soil layers (i.e. quantity of layers and their thicknesses) to better understand the sensitivity of vertical discretization of soil columns on soil moisture variability in ESMs. We present multivariate and multi-scale evaluation for the different model options and suggest ways to move forward with future model improvements.

  9. Phylogeny of Symbiotic Genes and the Symbiotic Properties of Rhizobia Specific to Astragalus glycyphyllos L.

    PubMed Central

    Gnat, Sebastian; Małek, Wanda; Oleńska, Ewa; Wdowiak-Wróbel, Sylwia; Kalita, Michał; Łotocka, Barbara; Wójcik, Magdalena

    2015-01-01

    The phylogeny of symbiotic genes of Astragalus glycyphyllos L. (liquorice milkvetch) nodule isolates was studied by comparative sequence analysis of nodA, nodC, nodH and nifH loci. In all these genes phylograms, liquorice milkvetch rhizobia (closely related to bacteria of three species, i.e. Mesorhizobium amorphae, Mesorhizobium septentrionale and Mesorhizobium ciceri) formed one clearly separate cluster suggesting the horizontal transfer of symbiotic genes from a single ancestor to the bacteria being studied. The high sequence similarity of the symbiotic genes of A. glycyphyllos rhizobia (99–100% in the case of nodAC and nifH genes, and 98–99% in the case of nodH one) points to the relatively recent (in evolutionary scale) lateral transfer of these genes. In the nodACH and nifH phylograms, A. glycyphyllos nodule isolates were grouped together with the genus Mesorhizobium species in one monophyletic clade, close to M. ciceri, Mesorhizobium opportunistum and Mesorhizobium australicum symbiovar biserrulae bacteria, which correlates with the close relationship of these rhizobia host plants. Plant tests revealed the narrow host range of A. glycyphyllos rhizobia. They formed effective symbiotic interactions with their native host (A. glycyphyllos) and Amorpha fruticosa but not with 11 other fabacean species. The nodules induced on A. glycyphyllos roots were indeterminate with apical, persistent meristem, an age gradient of nodule tissues and cortical vascular bundles. To reflect the symbiosis-adaptive phenotype of rhizobia, specific for A. glycyphyllos, we propose for these bacteria the new symbiovar “glycyphyllae”, based on nodA and nodC genes sequences. PMID:26496493

  10. Aviation system capacity improvements through technology

    NASA Technical Reports Server (NTRS)

    Harvey, W. Don

    1995-01-01

    A study was conducted with the primary objective of determining the impact of technology on capacity improvements in the U.S. air transportation system and, consequently, to assess the areas where NASA's expertise and technical contributions would be the most beneficial. The outlook of the study is considered both near- and long-term (5 to 25 years). The approach was that of actively working with the Massachusetts Institute of Technology (MIT) Flight Transportation Laboratory and included interactions with 'users' outside of both agencies as well as with organizations within. This report includes an overall survey of what are believed to be the causes of the capacity problems, ongoing work with the Federal Aviation Administration (FAA) to alleviate the problems, and identifies improvements in technology that would increase capacity and reduce delays.

  11. Improvements in continuum modeling for biomolecular systems

    NASA Astrophysics Data System (ADS)

    Yu, Qiao; Ben-Zhuo, Lu

    2016-01-01

    Modeling of biomolecular systems plays an essential role in understanding biological processes, such as ionic flow across channels, protein modification or interaction, and cell signaling. The continuum model described by the Poisson- Boltzmann (PB)/Poisson-Nernst-Planck (PNP) equations has made great contributions towards simulation of these processes. However, the model has shortcomings in its commonly used form and cannot capture (or cannot accurately capture) some important physical properties of the biological systems. Considerable efforts have been made to improve the continuum model to account for discrete particle interactions and to make progress in numerical methods to provide accurate and efficient simulations. This review will summarize recent main improvements in continuum modeling for biomolecular systems, with focus on the size-modified models, the coupling of the classical density functional theory and the PNP equations, the coupling of polar and nonpolar interactions, and numerical progress. Project supported by the National Natural Science Foundation of China (Grant No. 91230106) and the Chinese Academy of Sciences Program for Cross & Cooperative Team of the Science & Technology Innovation.

  12. Symbiote transmission and maintenance of extra-genomic associations.

    PubMed

    Fitzpatrick, Benjamin M

    2014-01-01

    Symbiotes can be transmitted from parents to offspring or horizontally from unrelated hosts or the environment. A key question is whether symbiote transmission is similar enough to Mendelian gene transmission to generate and maintain coevolutionary associations between host and symbiote genes. Recent papers come to opposite conclusions, with some suggesting that any horizontal transmission eliminates genetic association. These studies are hard to compare owing to arbitrary differences in modeling approach, parameter values, and assumptions about selection. I show that associations between host and symbiote genes (extra-genomic associations) can be described by the same dynamic model as conventional linkage disequilibria between genes in the same genome. Thus, covariance between host and symbiote genomes depends on population history, geographic structure, selection, and co-transmission rate, just as covariance between genes within a genome. The conclusion that horizontal transmission rapidly erodes extra-genomic associations is equivalent to the conclusion that recombination rapidly erodes associations between genes within a genome. The conclusion is correct in the absence of population structure or selection. However, population structure can maintain spatial associations between host and symbiote traits, and non-additive selection (interspecific epistasis) can generate covariances between host and symbiote genotypes. These results can also be applied to cultural or other non-genetic traits. This work contributes to a growing consensus that genomic, symbiotic, and gene-culture evolution can be analyzed under a common theoretical framework. In terms of coevolutionary potential, symbiotes can be viewed as lying on a continuum between the intimacy of genes and the indifference of casually co-occurring species. PMID:24605109

  13. Symbiote transmission and maintenance of extra-genomic associations

    PubMed Central

    Fitzpatrick, Benjamin M.

    2014-01-01

    Symbiotes can be transmitted from parents to offspring or horizontally from unrelated hosts or the environment. A key question is whether symbiote transmission is similar enough to Mendelian gene transmission to generate and maintain coevolutionary associations between host and symbiote genes. Recent papers come to opposite conclusions, with some suggesting that any horizontal transmission eliminates genetic association. These studies are hard to compare owing to arbitrary differences in modeling approach, parameter values, and assumptions about selection. I show that associations between host and symbiote genes (extra-genomic associations) can be described by the same dynamic model as conventional linkage disequilibria between genes in the same genome. Thus, covariance between host and symbiote genomes depends on population history, geographic structure, selection, and co-transmission rate, just as covariance between genes within a genome. The conclusion that horizontal transmission rapidly erodes extra-genomic associations is equivalent to the conclusion that recombination rapidly erodes associations between genes within a genome. The conclusion is correct in the absence of population structure or selection. However, population structure can maintain spatial associations between host and symbiote traits, and non-additive selection (interspecific epistasis) can generate covariances between host and symbiote genotypes. These results can also be applied to cultural or other non-genetic traits. This work contributes to a growing consensus that genomic, symbiotic, and gene-culture evolution can be analyzed under a common theoretical framework. In terms of coevolutionary potential, symbiotes can be viewed as lying on a continuum between the intimacy of genes and the indifference of casually co-occurring species. PMID:24605109

  14. Symbiotic Stars on Asiago Archive Plates

    NASA Astrophysics Data System (ADS)

    Jurdana-Šepić, Rajka; Munari, Ulisse

    2010-01-01

    The Asiago photographic archive has been searched for plates containing the symbiotic stars AS 210, AS 327, AX Per, BF Cyg, CI Cyg, DT Ser, EG And, GH Gem, Hen 2-442, Hen 3-1591, HM Sge, MaC 1-17, NSV 11776, Pe 2-16, Pt 1, PU Vul, RS Oph, T CrB, UV Aur, V1016 Cyg, V1329 Cyg, V352 Aql, V4018 Sgr, Wray 15-1470, and Z And. A total of 1617 good-quality plates imaging the program stars have been found and their brightness has been estimated using the Henden & Munari UBVRCIC local photometric sequences. The results for the objects with most abundant measurements are discussed.

  15. The role of symbiotic nitrogen fixation in sustainable production of biofuels.

    PubMed

    Biswas, Bandana; Gresshoff, Peter M

    2014-01-01

    With the ever-increasing population of the world (expected to reach 9.6 billion by 2050), and altered life style, comes an increased demand for food, fuel and fiber. However, scarcity of land, water and energy accompanied by climate change means that to produce enough to meet the demands is getting increasingly challenging. Today we must use every avenue from science and technology available to address these challenges. The natural process of symbiotic nitrogen fixation, whereby plants such as legumes fix atmospheric nitrogen gas to ammonia, usable by plants can have a substantial impact as it is found in nature, has low environmental and economic costs and is broadly established. Here we look at the importance of symbiotic nitrogen fixation in the production of biofuel feedstocks; how this process can address major challenges, how improving nitrogen fixation is essential, and what we can do about it. PMID:24786096

  16. The Role of Symbiotic Nitrogen Fixation in Sustainable Production of Biofuels

    PubMed Central

    Biswas, Bandana; Gresshoff, Peter M.

    2014-01-01

    With the ever-increasing population of the world (expected to reach 9.6 billion by 2050), and altered life style, comes an increased demand for food, fuel and fiber. However, scarcity of land, water and energy accompanied by climate change means that to produce enough to meet the demands is getting increasingly challenging. Today we must use every avenue from science and technology available to address these challenges. The natural process of symbiotic nitrogen fixation, whereby plants such as legumes fix atmospheric nitrogen gas to ammonia, usable by plants can have a substantial impact as it is found in nature, has low environmental and economic costs and is broadly established. Here we look at the importance of symbiotic nitrogen fixation in the production of biofuel feedstocks; how this process can address major challenges, how improving nitrogen fixation is essential, and what we can do about it. PMID:24786096

  17. Three Fundamental Periods in an 87 Year Light Curve of the Symbiotic Star MWC 560

    NASA Astrophysics Data System (ADS)

    Leibowitz, Elia M.; Formiggini, Liliana

    2015-08-01

    We construct a visual light curve of the symbiotic star MWC covering the last 87 years of its history. The data were assembled from the literature and from the AAVSO data bank. Most of the periodic components of the system brightness variation can be accounted for by the operation of three basic clocks of the periods P1 = 19,000 days, P2 = 1943 days, and P3 = 722 days. These periods can plausibly, and consistently with the observations, be attributed to three physical mechanisms in the system: the working of a solar-like magnetic dynamo cycle in the outer layers of the giant star of the system, the binary orbit cycle, and the sidereal rotation cycle of the giant star. MWC 560 is the seventh symbiotic star with historical light curves that reveal similar basic characteristics of the systems. The light curves of all these stars are well interpreted on the basis of the current understanding of the physical processes that are the major sources of the optical luminosity of these symbiotic systems.

  18. Instrumentation for Improvement of Gas Imaging Systems

    NASA Astrophysics Data System (ADS)

    Happer, William

    2002-08-01

    Funds from the AFOSR:DURIP grant F49620-01-1-0254 have been used to purchase three major pieces of equipment: (1) a nuclear magnetic resonance-spectrometer; system for studies of the basic-physics of hyperpolarized.Xe-129 and He-3 gases; (2) a 9.4 T superconducting magnet with a 3 inch room temperature bore; (3) a Verdi diode-pumped Nd:YAG laser to replace the very expensive argon ion laser we have traditionally used for pumping our Ti:sapphire tunable laser. This new equipment has greatly improved the research productivity of our laboratory.

  19. SLAC modulator system improvements and reliability results

    SciTech Connect

    Donaldson, A.R.

    1998-06-01

    In 1995, an improvement project was completed on the 244 klystron modulators in the linear accelerator. The modulator system has been previously described. This article offers project details and their resulting effect on modulator and component reliability. Prior to the project, the authors had collected four operating cycles (1991 through 1995) of MTTF data. In this discussion, the '91 data will be excluded since the modulators operated at 60 Hz. The five periods following the '91 run were reviewed due to the common repetition rate at 120 Hz.

  20. Surface Operations Systems Improve Airport Efficiency

    NASA Technical Reports Server (NTRS)

    2009-01-01

    With Small Business Innovation Research (SBIR) contracts from Ames Research Center, Mosaic ATM of Leesburg, Virginia created software to analyze surface operations at airports. Surface surveillance systems, which report locations every second for thousands of air and ground vehicles, generate massive amounts of data, making gathering and analyzing this information difficult. Mosaic?s Surface Operations Data Analysis and Adaptation (SODAA) tool is an off-line support tool that can analyze how well the airport surface operation is working and can help redesign procedures to improve operations. SODAA helps researchers pinpoint trends and correlations in vast amounts of recorded airport operations data.

  1. An improved drone tracking control system transponder

    NASA Astrophysics Data System (ADS)

    Miller, James J.; Tannenholz, Philip H.

    A small, compact, and inexpensive method of achieving frequency stability of a solid state LO to +/- 1 MHz in the MD700C-1 drone tracking and control system C-band command and control transponder is described. The methodology for realizing improved RF rejection, local oscillator stability, automatic gain control, and power supply efficiency is discussed. A switching mode regulator and a nonsaturating power supply were designed to operate at 80 percent efficiency to reduce power consumption and heat while operating over a wide voltage range.

  2. Improved orbiter waste collection system study

    NASA Technical Reports Server (NTRS)

    Bastin, P. H.

    1984-01-01

    Design concepts for improved fecal waste collection both on the space shuttle orbiter and as a precursor for the space station are discussed. Inflight usage problems associated with the existing orbiter waste collection subsystem are considered. A basis was sought for the selection of an optimum waste collection system concept which may ultimately result in the development of an orbiter flight test article for concept verification and subsequent production of new flight hardware. Two concepts were selected for orbiter and are shown in detail. Additionally, one concept selected for application to the space station is presented.

  3. Computer symbiosis: Emergence of symbiotic behavior through evolution

    SciTech Connect

    Ikegami, Takashi; Kaneko, Kunihiko

    1989-01-01

    Symbiosis is altruistic cooperation between distinct species. It is one of the most effective evolutionary processes, but its dynamics are not well understood as yet. A simple model of symbiosis is introduced, where we consider interactions between hosts and parasites and also mutations of hosts and parasites. It is found that a symbiotic state emerges for a suitable range of mutation rates. The symbiotic state is not static, but dynamically oscillates. Harmful parasites violating symbiosis appear periodically, but are rapidly extinguished by hosts and other parasites, and the symbiotic state is recovered. The emergence of ''Tit for Tat'' strategy to maintain symbiosis is discussed. 4 figs.

  4. AG Pegasi - now a classical symbiotic star in outburst?

    NASA Astrophysics Data System (ADS)

    Tomov, T. V.; Stoyanov, K. A.; Zamanov, R. K.

    2016-08-01

    Optical spectroscopy study of the recent AG Peg outburst observed during the second half of 2015 is presented. Considerable variations of the intensity and the shape of the spectral features as well as the changes of the hot component parameters, caused by the outburst, are discussed and certain similarities between the outburst of AG Peg and the outburst of a classical symbiotic stars are shown. It seems that after the end of the symbiotic nova phase, AG Peg became a member of the classical symbiotic stars group.

  5. Advanced kick detection systems improve HPHT operations

    SciTech Connect

    Harris, T.W.R.; Hendriks, P.; Surewaard, J.H.G.

    1995-09-01

    Many high-pressure, high-temperature (HPHT) wells are often characterized by the small margins that can exist between pore pressure and formation strength. Therefore, it is not surprising that kicks are far more likely to occur in HPHT wells and that a greater risk of internal blowout exists. The development and application of advanced kick detection systems for HPHT wells can help manage risks and improve drilling efficiency. Such systems enable earlier well shut-in, minimizing both the influx volume and the subsequent well bore pressures. This in turn lowers the risk, time and cost required for well control operations. Carefully considered application of these systems can also justify favorable economic benefits by optimization of the HPHT preliminary casing design. Minimizing kick volume can be important for the critical HPHT hole sections, where a reduced operating margin between pore pressure and fracture gradient exists, defining small design kick tolerance limits to permit safe drilling ahead to reach specified objectives. Kick detection for HPHT wells equivalent to less than 5 bbl of gas influx are often necessary to adequately minimize the risk of internal blowout and obtain the same levels of safety which are applied to conventional wells. This paper reviews these systems for both on-shore and off-shore operations.

  6. Outburst Activity Driven by Evolved Pulsating Star in the Symbiotic Binary AG Dra

    NASA Astrophysics Data System (ADS)

    Gális, R.; Hric, L.; Leedjärv, L.

    2015-12-01

    The symbiotic system AG Dra regularly undergoes quiescent and active stages which consist of the series of individual outbursts. The period analysis of new and historical photometric data, as well as radial velocities, confirmed the presence of the two periods. The longer one around ≈ 550 d is related to the orbital motion and the shorter one ≈355 d could be due to pulsation of the cool component of AG Dra.

  7. Biochemical Approaches to Improved Nitrogen Fixation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improving symbiotic nitrogen fixation by legumes has emerged again as an important topic on the world scene due to the energy crisis and lack of access to nitrogen fertilizer in developing countries. We have taken a biochemical genomics approach to improving symbiotic nitrogen fixation in legumes. L...

  8. A systems approach to understanding and improving health systems.

    PubMed

    Erazo, Álvaro

    2015-09-01

    Health systems face the challenge of helping to improve health conditions. They occupy a priority place in middle- and lower-income countries, since the absence or fragility of health systems adversely impacts expected health outcomes. Thus, due to the direct relationship between programs and systems, the absence or weakness of either will result in a consequent deficiency in public health and the very execution of the programs. In the same vein, weakened health systems are one of the main bottlenecks to attaining the Millennium Development Goals. Systems thinking is one of the "four revolutions in progress" that are helping to transform health and health care systems. Within that framework, this article identifies conceptual and operational elements of systems applicable to health systems that contribute to overcoming the obstacles and inertia that hinder health activities and outcomes. It discusses relevant concepts characteristic of systems thinking, such as structural variables and dynamic complexity, the relationship between programs and health systems, and the monitoring and evaluation function, together with the role of innovation and systems integration as high-priority elements. This will aid in the development of designs that also stress the context of the components that guide management, identifying processes and outcomes in a health management continuum. PMID:26758004

  9. Towards the minimal nitrogen-fixing symbiotic genome.

    PubMed

    Sanjuán, Juan

    2016-09-01

    diCenzo and coworkers have reverse engineered a rhizobium into a non-nitrogen fixer, creating a genomic platform for gain-of-function genetics studies, which should aid to identify the minimal nitrogen fixing symbiotic genome. PMID:27188818

  10. LES ARM Symbiotic Simulation and Observation (LASSO) Implementation Strategy

    SciTech Connect

    Gustafson Jr., WI; Vogelmann, AM

    2015-09-01

    This document illustrates the design of the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) workflow to provide a routine, high-resolution modeling capability to augment the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s high-density observations. LASSO will create a powerful new capability for furthering ARM’s mission to advance understanding of cloud, radiation, aerosol, and land-surface processes. The combined observational and modeling elements will enable a new level of scientific inquiry by connecting processes and context to observations and providing needed statistics for details that cannot be measured. The result will be improved process understanding that facilitates concomitant improvements in climate model parameterizations. The initial LASSO implementation will be for ARM’s Southern Great Plains site in Oklahoma and will focus on shallow convection, which is poorly simulated by climate models due in part to clouds’ typically small spatial scale compared to model grid spacing, and because the convection involves complicated interactions of microphysical and boundary layer processes.

  11. Symbiotic relationship of thiothrix spp. with An echinoderm

    PubMed

    Brigmon; De Ridder C

    1998-09-01

    Immunoassay procedures were used to investigate the symbiotic relationship of Thiothrix spp. in the intestinal cecum of the spatangoid species Echinocardium cordatum. Thiothrix spp. were identified in nodule samples from E. cordatum digestive tubes based on microscopic examination, enzyme-linked immunosorbent assay, and indirect immunofluorescence. Thiothrix spp. protein made up as much as 84% of the total protein content of the nodules. This is the first identification of Thiothrix spp. internally symbiotic with marine invertebrates. PMID:9726902

  12. Symbiotic Relationship of Thiothrix spp. with an Echinoderm†

    PubMed Central

    Brigmon, Robin L.; De Ridder, Chantal

    1998-01-01

    Immunoassay procedures were used to investigate the symbiotic relationship of Thiothrix spp. in the intestinal cecum of the spatangoid species Echinocardium cordatum. Thiothrix spp. were identified in nodule samples from E. cordatum digestive tubes based on microscopic examination, enzyme-linked immunosorbent assay, and indirect immunofluorescence. Thiothrix spp. protein made up as much as 84% of the total protein content of the nodules. This is the first identification of Thiothrix spp. internally symbiotic with marine invertebrates. PMID:9726902

  13. Sensitive response of a model of symbiotic ecosystem to seasonal periodic drive

    SciTech Connect

    Rekker, A.; Lumi, N.; Mankin, R.

    2014-11-12

    A symbiotic ecosysytem (metapopulation) is studied by means of the stochastic Lotka-Volterra model with generalized Verhulst self-regulation. The effect of variable environment on the carrying capacities of populations is taken into account as an asymmetric dichotomous noise and as a deterministic periodic stimulus. In the framework of the mean-field theory an explicit self-consistency equation for the system in the long-time limit is presented. Also, expressions for the probability distribution and for the moments of the population size are found. In certain cases the mean population size exhibits large oscillations in time, even if the amplitude of the seasonal environmental drive is small. Particularly, it is shown that the occurrence of large oscillations of the mean population size can be controlled by noise parameters (such as amplitude and correlation time) and by the coupling strength of the symbiotic interaction between species.

  14. Symbiotic lactobacilli stimulate gut epithelial proliferation via Nox-mediated generation of reactive oxygen species

    PubMed Central

    Jones, Rheinallt M; Luo, Liping; Ardita, Courtney S; Richardson, Arena N; Kwon, Young Man; Mercante, Jeffrey W; Alam, Ashfaqul; Gates, Cymone L; Wu, Huixia; Swanson, Phillip A; Lambeth, J David; Denning, Patricia W; Neish, Andrew S

    2013-01-01

    The resident prokaryotic microbiota of the metazoan gut elicits profound effects on the growth and development of the intestine. However, the molecular mechanisms of symbiotic prokaryotic–eukaryotic cross-talk in the gut are largely unknown. It is increasingly recognized that physiologically generated reactive oxygen species (ROS) function as signalling secondary messengers that influence cellular proliferation and differentiation in a variety of biological systems. Here, we report that commensal bacteria, particularly members of the genus Lactobacillus, can stimulate NADPH oxidase 1 (Nox1)-dependent ROS generation and consequent cellular proliferation in intestinal stem cells upon initial ingestion into the murine or Drosophila intestine. Our data identify and highlight a highly conserved mechanism that symbiotic microorganisms utilize in eukaryotic growth and development. Additionally, the work suggests that specific redox-mediated functions may be assigned to specific bacterial taxa and may contribute to the identification of microbes with probiotic potential. PMID:24141879

  15. Sensitive response of a model of symbiotic ecosystem to seasonal periodic drive

    NASA Astrophysics Data System (ADS)

    Rekker, A.; Lumi, N.; Mankin, R.

    2014-11-01

    A symbiotic ecosysytem (metapopulation) is studied by means of the stochastic Lotka-Volterra model with generalized Verhulst self-regulation. The effect of variable environment on the carrying capacities of populations is taken into account as an asymmetric dichotomous noise and as a deterministic periodic stimulus. In the framework of the mean-field theory an explicit self-consistency equation for the system in the long-time limit is presented. Also, expressions for the probability distribution and for the moments of the population size are found. In certain cases the mean population size exhibits large oscillations in time, even if the amplitude of the seasonal environmental drive is small. Particularly, it is shown that the occurrence of large oscillations of the mean population size can be controlled by noise parameters (such as amplitude and correlation time) and by the coupling strength of the symbiotic interaction between species.

  16. Characterizing and Improving Distributed Intrusion Detection Systems.

    SciTech Connect

    Hurd, Steven A.; Proebstel, Elliot P.

    2007-11-01

    Due to ever-increasing quantities of information traversing networks, network administrators are developing greater reliance upon statistically sampled packet information as the source for their intrusion detection systems (IDS). Our research is aimed at understanding IDS performance when statistical packet sampling is used. Using the Snort IDS and a variety of data sets, we compared IDS results when an entire data set is used to the results when a statistically sampled subset of the data set is used. Generally speaking, IDS performance with statistically sampled information was shown to drop considerably even under fairly high sampling rates (such as 1:5). Characterizing and Improving Distributed Intrusion Detection Systems4AcknowledgementsThe authors wish to extend our gratitude to Matt Bishop and Chen-Nee Chuah of UC Davis for their guidance and support on this work. Our thanks are also extended to Jianning Mai of UC Davis and Tao Ye of Sprint Advanced Technology Labs for their generous assistance.We would also like to acknowledge our dataset sources, CRAWDAD and CAIDA, without which this work would not have been possible. Support for OC48 data collection is provided by DARPA, NSF, DHS, Cisco and CAIDA members.

  17. Improving Steam System Performance: A Sourcebook for Industry, Second Edition

    SciTech Connect

    2012-02-23

    This sourcebook is designed to provide steam system users with a reference that describes the basic steam system components, outlines opportunities for energy and performance improvements, and discusses the benefits of a systems approach in identifying and implementing these improvement opportunities. The sourcebook is divided into three main sections: steam system basics, performance improvement opportunities, and where to find help.

  18. Improved Refractories for IGCC Power Systems

    SciTech Connect

    Dogan, Cynthia P.; Kwong, Kyei-Sing; Bennett, James P.; Chinn, Richard E.; Dahlin, Cheryl L.

    2002-01-01

    The gasification of coal, petroleum residuals, and biomass provides the opportunity to produce energy more efficiently, and with significantly less environmental impact, than more-conventional combustion-based processes. In addition, the synthesis gas that is the product of the gasification process offers the gasifier operator the option of ''polygeneration'', i.e., the production of alternative products instead of power should it be economically favorable to do so. Because of these advantages, gasification is a key element in the U.S. Department of Energy?s Vision 21 power system. However, issues with both the reliability and the economics of gasifier operation will have to be resolved before gasification will be widely adopted by the power industry. Central to both increased reliability and economics is the development of materials with longer service lives in gasifier systems that can provide extended periods of continuous gasifier operation. The focus of the Advanced Refractories for Gasification project at the Albany Research Center is to develop improved materials capable of withstanding the harsh, high-temperature environment created by the gasification reaction, and includes both the refractory lining that insulates the slagging gasifier, as well as the thermocouple assemblies that are utilized to monitor gasifier operating temperatures. Current generation refractory liners in slagging gasifiers are typically replaced every 10 to 18 months, at costs ranging up to $2,000,000. Compounding materials and installation costs are the lost-opportunity costs for the three to four weeks that the gasifier is off-line for the refractory exchange. Current generation thermocouple devices rarely survive the gasifier start-up process, leaving the operator with no real means of temperature measurement during gasifier operation. As a result, the goals of this project include the development of a refractory liner with a service life at least double that of current generation

  19. Improving robustness of speech recognition systems

    NASA Astrophysics Data System (ADS)

    Mitra, Vikramjit

    2010-11-01

    speech databases: X-ray microbeam and Aurora-2 were annotated, where the former was used to train a TV-estimator and the latter was used to train a Dynamic Bayesian Network (DBN) based ASR architecture. The DBN architecture used two sets of observation: (a) acoustic features in the form of mel-frequency cepstral coefficients (MFCCs) and (b) TVs (estimated from the acoustic speech signal). In this setup the articulatory gestures were modeled as hidden random variables, hence eliminating the necessity for explicit gesture recognition. Word recognition results using the DBN architecture indicate that articulatory representations not only can help to account for coarticulatory variations but can also significantly improve the noise robustness of ASR system.

  20. SINFAC - SYSTEMS IMPROVED NUMERICAL FLUIDS ANALYSIS CODE

    NASA Technical Reports Server (NTRS)

    Costello, F. A.

    1994-01-01

    The Systems Improved Numerical Fluids Analysis Code, SINFAC, consists of additional routines added to the April 1983 revision of SINDA, a general thermal analyzer program. The purpose of the additional routines is to allow for the modeling of active heat transfer loops. The modeler can simulate the steady-state and pseudo-transient operations of 16 different heat transfer loop components including radiators, evaporators, condensers, mechanical pumps, reservoirs and many types of valves and fittings. In addition, the program contains a property analysis routine that can be used to compute the thermodynamic properties of 20 different refrigerants. SINFAC can simulate the response to transient boundary conditions. SINFAC was first developed as a method for computing the steady-state performance of two phase systems. It was then modified using CNFRWD, SINDA's explicit time-integration scheme, to accommodate transient thermal models. However, SINFAC cannot simulate pressure drops due to time-dependent fluid acceleration, transient boil-out, or transient fill-up, except in the accumulator. SINFAC also requires the user to be familiar with SINDA. The solution procedure used by SINFAC is similar to that which an engineer would use to solve a system manually. The solution to a system requires the determination of all of the outlet conditions of each component such as the flow rate, pressure, and enthalpy. To obtain these values, the user first estimates the inlet conditions to the first component of the system, then computes the outlet conditions from the data supplied by the manufacturer of the first component. The user then estimates the temperature at the outlet of the third component and computes the corresponding flow resistance of the second component. With the flow resistance of the second component, the user computes the conditions down stream, namely the inlet conditions of the third. The computations follow for the rest of the system, back to the first component

  1. Symbiotic two-species contact process.

    PubMed

    de Oliveira, Marcelo Martins; Dos Santos, Renato Vieira; Dickman, Ronald

    2012-07-01

    We study a contact process (CP) with two species that interact in a symbiotic manner. In our model, each site of a lattice may be vacant or host individuals of species A and/or B; multiple occupancy by the same species is prohibited. Symbiosis is represented by a reduced death rate μ<1 for individuals at sites with both species present. Otherwise, the dynamics is that of the basic CP, with creation (at vacant neighbor sites) at rate λ and death of (isolated) individuals at a rate of unity. Mean-field theory and Monte Carlo simulation show that the critical creation rate λ(c)(μ) is a decreasing function of μ, even though a single-species population must go extinct for λ<λ(c) (1), the critical point of the basic CP. Extensive simulations yield results for critical behavior that are compatible with the directed percolation (DP) universality class, but with unusually strong corrections to scaling. A field-theoretic argument supports the conclusion of DP critical behavior. We obtain similar results for a CP with creation at second-neighbor sites and enhanced survival at first neighbors in the form of an annihilation rate that decreases with the number of occupied first neighbors. PMID:23005382

  2. Symbiotic two-species contact process

    NASA Astrophysics Data System (ADS)

    de Oliveira, Marcelo Martins; Dos Santos, Renato Vieira; Dickman, Ronald

    2012-07-01

    We study a contact process (CP) with two species that interact in a symbiotic manner. In our model, each site of a lattice may be vacant or host individuals of species A and/or B; multiple occupancy by the same species is prohibited. Symbiosis is represented by a reduced death rate μ<1 for individuals at sites with both species present. Otherwise, the dynamics is that of the basic CP, with creation (at vacant neighbor sites) at rate λ and death of (isolated) individuals at a rate of unity. Mean-field theory and Monte Carlo simulation show that the critical creation rate λc(μ) is a decreasing function of μ, even though a single-species population must go extinct for λ<λc(1), the critical point of the basic CP. Extensive simulations yield results for critical behavior that are compatible with the directed percolation (DP) universality class, but with unusually strong corrections to scaling. A field-theoretic argument supports the conclusion of DP critical behavior. We obtain similar results for a CP with creation at second-neighbor sites and enhanced survival at first neighbors in the form of an annihilation rate that decreases with the number of occupied first neighbors.

  3. Intracellular pH of symbiotic dinoflagellates

    NASA Astrophysics Data System (ADS)

    Gibbin, E. M.; Davy, S. K.

    2013-09-01

    Intracellular pH (pHi) is likely to play a key role in maintaining the functional success of cnidarian-dinoflagellate symbiosis, yet until now the pHi of the symbiotic dinoflagellates (genus Symbiodinium) has never been quantified. Flow cytometry was used in conjunction with the ratiometric fluorescent dye BCECF to monitor changes in pHi over a daily light/dark cycle. The pHi of Symbiodinium type B1 freshly isolated from the model sea anemone Aiptasia pulchella was 7.25 ± 0.01 (mean ± SE) in the light and 7.10 ± 0.02 in the dark. A comparable effect of irradiance was seen across a variety of cultured Symbiodinium genotypes (types A1, B1, E1, E2, F1, and F5) which varied between pHi 7.21-7.39 in the light and 7.06-7.14 in the dark. Of note, there was a significant genotypic difference in pHi, irrespective of irradiance.

  4. Superfinished Surfaces for Power Transfer Systems Improvement

    NASA Technical Reports Server (NTRS)

    Niskanen, Paul; Manesh, Ali; Warren, Alford; Krantz, Timothy

    2002-01-01

    The continuous demands for high performance and lightweight power train systems resulted in requirements for higher power density gearing systems. However, increasing the load bearing capacity of the gear teeth, without increasing size, places stringent requirements upon metallurgy, dimensional control, and surface finish of the final products. In order to operate the mating parts near the upper bounds of their theoretical design envelope, manufacturing processes are required that are capable of improving the fatigue life and load bearing capacity of precision parts, while producing the required geometric accuracy. Results of the recent experimental studies indicate that the super finishing process is able to achieve these goals. This paper will review the results of our continuing evaluation of the super finish process as applied to aerospace gearing. Two separate evaluations were performed on gears to examine the effects of super finishing on resistance to both pitting and contact fatigue. For the reported experiments, both conventional and super finished test gears were simultaneously manufactured using the same process and the same heat lot of materials. This paper will also provide a brief description of the manufacturing technology used to achieve the results and will compare the results with other published data. In addition, this paper presents a couple of off-the-shelf manufacturing technologies that have been successfully used to super finish test specimens and will provide a glimpse of other emerging super finishing technologies. This is a US Army Manufacturing Technology project. The project was sponsored by the Aviation and Missiles Command (AMCOM) and was being managed and conducted by IIT Research Institute.

  5. Genomic characterization of symbiotic mycoplasmas from the stomach of deep-sea isopod bathynomus sp.

    PubMed

    Wang, Yong; Huang, Jiao-Mei; Wang, Shao-Lu; Gao, Zhao-Ming; Zhang, Ai-Qun; Danchin, Antoine; He, Li-Sheng

    2016-09-01

    Deep-sea isopod scavengers such as Bathynomus sp. are able to live in nutrient-poor environments, which is likely attributable to the presence of symbiotic microbes in their stomach. In this study we recovered two draft genomes of mycoplasmas, Bg1 and Bg2, from the metagenomes of the stomach contents and stomach sac of a Bathynomus sp. sample from the South China Sea (depth of 898 m). Phylogenetic trees revealed a considerable genetic distance to other mycoplasma species for Bg1 and Bg2. Compared with terrestrial symbiotic mycoplasmas, the Bg1 and Bg2 genomes were enriched with genes encoding phosphoenolpyruvate-dependent phosphotransferase systems (PTSs) and sodium-driven symporters responsible for the uptake of sugars, amino acids and other carbohydrates. The genome of mycoplasma Bg1 contained sialic acid lyase and transporter genes, potentially enabling the bacteria to attach to the stomach sac and obtain organic carbons from various cell walls. Both of the mycoplasma genomes contained multiple copies of genes related to proteolysis and oligosaccharide degradation, which may help the host survive in low-nutrient conditions. The discovery of the different types of mycoplasma bacteria in the stomach of this deep-sea isopod affords insights into symbiotic model of deep-sea animals and genomic plasticity of mycoplasma bacteria. PMID:27312602

  6. A role for the mevalonate pathway in early plant symbiotic signaling

    PubMed Central

    Venkateshwaran, Muthusubramanian; Jayaraman, Dhileepkumar; Chabaud, Mireille; Genre, Andrea; Balloon, Allison J.; Maeda, Junko; Forshey, Kari; den Os, Désirée; Kwiecien, Nicholas W.; Coon, Joshua J.; Barker, David G.; Ané, Jean-Michel

    2015-01-01

    Rhizobia and arbuscular mycorrhizal fungi produce signals that are perceived by host legume receptors at the plasma membrane and trigger sustained oscillations of the nuclear and perinuclear Ca2+ concentration (Ca2+ spiking), which in turn leads to gene expression and downstream symbiotic responses. The activation of Ca2+ spiking requires the plasma membrane-localized receptor-like kinase Does not Make Infections 2 (DMI2) as well as the nuclear cation channel DMI1. A key enzyme regulating the mevalonate (MVA) pathway, 3-Hydroxy-3-Methylglutaryl CoA Reductase 1 (HMGR1), interacts with DMI2 and is required for the legume–rhizobium symbiosis. Here, we show that HMGR1 is required to initiate Ca2+ spiking and symbiotic gene expression in Medicago truncatula roots in response to rhizobial and arbuscular mycorrhizal fungal signals. Furthermore, MVA, the direct product of HMGR1 activity, is sufficient to induce nuclear-associated Ca2+ spiking and symbiotic gene expression in both wild-type plants and dmi2 mutants, but interestingly not in dmi1 mutants. Finally, MVA induced Ca2+ spiking in Human Embryonic Kidney 293 cells expressing DMI1. This demonstrates that the nuclear cation channel DMI1 is sufficient to support MVA-induced Ca2+ spiking in this heterologous system. PMID:26199419

  7. Chemical abundance analysis of symbiotic giants. RW Hya, SY Mus, BX Mon, and AE Ara

    NASA Astrophysics Data System (ADS)

    Galan, C.; Mikolajewska, J.; Hinkle, K. H.; Schmidt, M. R.; Gromadzki, M.

    2014-04-01

    Symbiotic stars are the long period, binary systems of strongly interacting stars at the final stages of evolution which can be useful tool to understand the chemical evolution of the Galaxy and the formation of stellar populations. Knowledge of the chemical composition of the symbiotic giants is essential to advancing our understanding of these issues but unfortunately reliably determinations exist only in a few cases. We perform a program for detailed chemical composition analysis in over 30 symbiotic giants, based on the high resolution, near-IR spectra, obtained with Phoenix/Gemini South spectrometer. The methods of the standard LTE analysis is used to obtain photospheric abundances of CNO and elements around iron peak. Here we present results obtained for four objects: RW Hya, SY Mus, BX Mon, and AE Ara. Our analysis revealed a significantly sub-solar metallicity (Me/H ~ -0.75) for RW Hya, a slightly sub-solar metallicities (Me/H ~ 0.2-0.3) in BX Mon and AE Ara, and a near-solar metallicity in SY Mus. 12C/13C isotopic ratios are low in all cases, ranging from ~6 to ~10.

  8. Far-infrared data for symbiotic stars. II - The IRAS survey observations

    NASA Technical Reports Server (NTRS)

    Kenyon, S. J.; Fernandez-Castro, T.; Stencel, R. E.

    1988-01-01

    IRAS survey data for all known symbiotic binaries are reported. S type systems have 25 micron excesses much larger than those of single red giant stars, suggesting that these objects lose mass more rapidly than do normal giants. D type objects have far-IR colors similar to those of Mira variables, implying mass-loss rate of about 10 to the -6th solar masses/yr. The near-IR extinctions of the D types indicate that their Mira components are enshrouded in optically thick dust shells, while their hot companions lie outside the shells. If this interpretation of the data is correct, then the very red near-IR colors of D type symbiotic stars are caused by extreme amounts of dust absorption rather than dust emission. The small group of D prime objects possesses far-IR colors resembling those of compact planetary nebulae or extreme OH/IR stars. It is speculated that these binaries are not symbiotic stars at all, but contain a hot compact star and an exasymptotic branch giant which is in the process of ejecting a planetary nebula shell.

  9. Symbiotic Nitrogen Fixation and the Challenges to Its Extension to Nonlegumes

    PubMed Central

    Mus, Florence; Crook, Matthew B.; Garcia, Kevin; Garcia Costas, Amaya; Geddes, Barney A.; Kouri, Evangelia D.; Paramasivan, Ponraj; Ryu, Min-Hyung; Oldroyd, Giles E. D.; Poole, Philip S.; Udvardi, Michael K.; Voigt, Christopher A.

    2016-01-01

    Access to fixed or available forms of nitrogen limits the productivity of crop plants and thus food production. Nitrogenous fertilizer production currently represents a significant expense for the efficient growth of various crops in the developed world. There are significant potential gains to be had from reducing dependence on nitrogenous fertilizers in agriculture in the developed world and in developing countries, and there is significant interest in research on biological nitrogen fixation and prospects for increasing its importance in an agricultural setting. Biological nitrogen fixation is the conversion of atmospheric N2 to NH3, a form that can be used by plants. However, the process is restricted to bacteria and archaea and does not occur in eukaryotes. Symbiotic nitrogen fixation is part of a mutualistic relationship in which plants provide a niche and fixed carbon to bacteria in exchange for fixed nitrogen. This process is restricted mainly to legumes in agricultural systems, and there is considerable interest in exploring whether similar symbioses can be developed in nonlegumes, which produce the bulk of human food. We are at a juncture at which the fundamental understanding of biological nitrogen fixation has matured to a level that we can think about engineering symbiotic relationships using synthetic biology approaches. This minireview highlights the fundamental advances in our understanding of biological nitrogen fixation in the context of a blueprint for expanding symbiotic nitrogen fixation to a greater diversity of crop plants through synthetic biology. PMID:27084023

  10. Composition of symbiotic bacteria predicts survival in Panamanian golden frogs infected with a lethal fungus

    PubMed Central

    Becker, Matthew H.; Walke, Jenifer B.; Cikanek, Shawna; Savage, Anna E.; Mattheus, Nichole; Santiago, Celina N.; Minbiole, Kevin P. C.; Harris, Reid N.; Belden, Lisa K.; Gratwicke, Brian

    2015-01-01

    Symbiotic microbes can dramatically impact host health and fitness, and recent research in a diversity of systems suggests that different symbiont community structures may result in distinct outcomes for the host. In amphibians, some symbiotic skin bacteria produce metabolites that inhibit the growth of Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen that has caused many amphibian population declines and extinctions. Treatment with beneficial bacteria (probiotics) prevents Bd infection in some amphibian species and creates optimism for conservation of species that are highly susceptible to chytridiomycosis, the disease caused by Bd. In a laboratory experiment, we used Bd-inhibitory bacteria from Bd-tolerant Panamanian amphibians in a probiotic development trial with Panamanian golden frogs, Atelopus zeteki, a species currently surviving only in captive assurance colonies. Approximately 30% of infected golden frogs survived Bd exposure by either clearing infection or maintaining low Bd loads, but this was not associated with probiotic treatment. Survival was instead related to initial composition of the skin bacterial community and metabolites present on the skin. These results suggest a strong link between the structure of these symbiotic microbial communities and amphibian host health in the face of Bd exposure and also suggest a new approach for developing amphibian probiotics. PMID:25788591

  11. Composition of symbiotic bacteria predicts survival in Panamanian golden frogs infected with a lethal fungus.

    PubMed

    Becker, Matthew H; Walke, Jenifer B; Cikanek, Shawna; Savage, Anna E; Mattheus, Nichole; Santiago, Celina N; Minbiole, Kevin P C; Harris, Reid N; Belden, Lisa K; Gratwicke, Brian

    2015-04-22

    Symbiotic microbes can dramatically impact host health and fitness, and recent research in a diversity of systems suggests that different symbiont community structures may result in distinct outcomes for the host. In amphibians, some symbiotic skin bacteria produce metabolites that inhibit the growth of Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen that has caused many amphibian population declines and extinctions. Treatment with beneficial bacteria (probiotics) prevents Bd infection in some amphibian species and creates optimism for conservation of species that are highly susceptible to chytridiomycosis, the disease caused by Bd. In a laboratory experiment, we used Bd-inhibitory bacteria from Bd-tolerant Panamanian amphibians in a probiotic development trial with Panamanian golden frogs, Atelopus zeteki, a species currently surviving only in captive assurance colonies. Approximately 30% of infected golden frogs survived Bd exposure by either clearing infection or maintaining low Bd loads, but this was not associated with probiotic treatment. Survival was instead related to initial composition of the skin bacterial community and metabolites present on the skin. These results suggest a strong link between the structure of these symbiotic microbial communities and amphibian host health in the face of Bd exposure and also suggest a new approach for developing amphibian probiotics. PMID:25788591

  12. Symbiotic Nitrogen Fixation and the Challenges to Its Extension to Nonlegumes.

    PubMed

    Mus, Florence; Crook, Matthew B; Garcia, Kevin; Garcia Costas, Amaya; Geddes, Barney A; Kouri, Evangelia D; Paramasivan, Ponraj; Ryu, Min-Hyung; Oldroyd, Giles E D; Poole, Philip S; Udvardi, Michael K; Voigt, Christopher A; Ané, Jean-Michel; Peters, John W

    2016-07-01

    Access to fixed or available forms of nitrogen limits the productivity of crop plants and thus food production. Nitrogenous fertilizer production currently represents a significant expense for the efficient growth of various crops in the developed world. There are significant potential gains to be had from reducing dependence on nitrogenous fertilizers in agriculture in the developed world and in developing countries, and there is significant interest in research on biological nitrogen fixation and prospects for increasing its importance in an agricultural setting. Biological nitrogen fixation is the conversion of atmospheric N2 to NH3, a form that can be used by plants. However, the process is restricted to bacteria and archaea and does not occur in eukaryotes. Symbiotic nitrogen fixation is part of a mutualistic relationship in which plants provide a niche and fixed carbon to bacteria in exchange for fixed nitrogen. This process is restricted mainly to legumes in agricultural systems, and there is considerable interest in exploring whether similar symbioses can be developed in nonlegumes, which produce the bulk of human food. We are at a juncture at which the fundamental understanding of biological nitrogen fixation has matured to a level that we can think about engineering symbiotic relationships using synthetic biology approaches. This minireview highlights the fundamental advances in our understanding of biological nitrogen fixation in the context of a blueprint for expanding symbiotic nitrogen fixation to a greater diversity of crop plants through synthetic biology. PMID:27084023

  13. Application of an improved intracardiac fibreoptic system.

    PubMed Central

    Krovetz, L J; Brenner, J I; Polanyi, M; Ostrowski, D

    1978-01-01

    An improved fibreoptic in vivo haemoreflection system has been used in over 200 patients. Continuous recording of oxygen saturation while moving the catheter permits measurement of simultaneous pressure and oxygen saturation at almost an unlimited number of sites through the right heart. The oxygen saturation can be continuously monitored and the response is sufficiently fast to permit investigation of changes in oxygen saturation during portions of the cardiac cycle. Dye dilution curves have been recorded from over 200 patients. The only blood withdrawn for the dye dilution curve was the 3 ml needed for checking the calibration of the instrument. We have found that the calibration is extremely stable. In some instances where it has been deemed impractical to obtain blood for calibration, the calibration factor for each catheter may be used. In any case, the calibration check is performed at the end of the study and does not present problems of sterility. The calibration factor may yield a correction factor which then applies uniformly to all the cardiac output values obtained during the study. Images PMID:708525

  14. On the nature of the symbiotic binary AX Persei

    NASA Technical Reports Server (NTRS)

    Mikolajewska, Joanna; Kenyon, Scott J.

    1992-01-01

    Photometric and spectroscopic observations of the symbiotic binary AX Persei are presented. This system contains a red giant that fills its tidal lobe and transfers material into an accretion disk surrounding a low-mass main-sequence star. The stellar masses - 1 solar mass for the red giant and about 0.4 solar mass for the companion - suggest AX Per is poised to enter a common envelope phase of evolution. The disk luminosity increases from L(disk) about 100 solar luminosity in quiescence to L(disk) about 5700 solar luminosity in outburst for a distance of d = 2.5 kpc. Except for visual maximum, high ionization permitted emission lines - such as He II - imply an EUV luminosity comparable to the disk luminosity. High-energy photons emitted by a hot boundary layer between the disk and central star ionize a surrounding nebula to produce this permitted line emission. High ionization forbidden lines form in an extended, shock-excited region well out of the binary's orbital plane and may be associated with mass loss from the disk.

  15. Defining Requirements for Improved Photovoltaic System Reliability

    SciTech Connect

    Maish, A.B.

    1998-12-21

    Reliable systems are an essential ingredient of any technology progressing toward commercial maturity and large-scale deployment. This paper defines reliability as meeting system fictional requirements, and then develops a framework to understand and quantify photovoltaic system reliability based on initial and ongoing costs and system value. The core elements necessary to achieve reliable PV systems are reviewed. These include appropriate system design, satisfactory component reliability, and proper installation and servicing. Reliability status, key issues, and present needs in system reliability are summarized for four application sectors.

  16. [The symbiotic microflora associated with the tegument of proteocephalidean cestodes and the intestines of their fish hosts].

    PubMed

    Korneva, Zh V; Plotnikov, A O

    2006-01-01

    The indigenous symbiotic microflora associated with the tegument of proteocephalidean cestodes and the intestines of their fish hosts has been investigated in morphological and ecological aspects. The indigenous microflora associated with the cestode tegument consists of the nannobacteria population, which was present obligatorily on the surface of tegument, and the "deep microflora". The deep microflora associates with some few species of parasites only. Each individual host-parasite micro-biocenosis includes specific indigenous symbiotic microorganisms, with the differing microfloras of host intestine and parasite. Physiology, biochemistry and/or diet of hosts apparently influence on the symbiotic microflora's structure of parasites. The least bacteria abundance and diversity of their morphotypes were observed in the parasites from baby fishes. The diversity and abundance of bacteria were increased with the fish host ageing and the formation of the definitive structure of its intestine. It is an evidence of the gradual invading of the intestinal parasites (cestodes) tegument by bacterial cells. The invading is realized on the base of the microflora that was present in the food of fish host. The symbiotic microflora has specific morphological features, can regulate the homeostasis of the cestodes and fish hosts and also can maintain equilibrium of alimentary and immune interrelations in the host-parasite system. PMID:17042276

  17. The C IV doublet ratio intensity effect in symbiotic stars

    NASA Technical Reports Server (NTRS)

    Michalitsianos, A. G.; Fahey, M.; Kafatos, M.; Viotti, R.; Cassatella, A.

    1988-01-01

    High-resolution UV spectra in the 1200-2000 wavelength range of the symbiotic variable R Aqr and its nebular jet were obtained in July 1987 with the IUE. The line profile structure of the C IV 1548, 1550 doublet in the jet indicates multicomponent velocity structure from an optically thin emitting gas. The C IV doublet profiles in the compact H II region engulfing the Mira and hot companion binary also suggest multicomponent structure with radial velocities up to about -100 km/s. The value of the doublet intensity ratio in the R Aqr H II region has been observed in other similar symbiotic stars, such as RX Pup. It is suggested that the anomalous behavior of the C IV doublet intensities may be useful for studying the spatial structure and temporal nature of winds in symbiotic stars.

  18. Symbiotic relationship of Thiothrix spp. with an echinoderm

    SciTech Connect

    Brigmon, R.L.; De Ridder, C.

    1998-09-01

    Thiothrix-like bacteria have been reported as symbionts in invertebrates from sulfide-rich habitats. Isolation of these symbiotic Thiothrix-like bacteria has failed, and the organisms have not been previously identified with certainty. The genus Thiothrix was created for ensheathed filamentous bacteria that oxidize sulfide and deposit sulfur granules internally, attach to substrates, produce gliding gonidia, and form rosettes. Immunoassay procedures were used to investigate the symbiotic relationship of Thiothrix spp. in the intestinal cecum of the spatangoid species Echinocardium cordatum. Thiothrix spp. were identified in nodule samples from E. cordatum digestive tubes based on microscopic examination, enzyme-linked immunosorbent assay, and indirect immunofluorescence. Thiothrix spp. protein made up as much as 84% of the total protein content of the nodules. This is the first identification of Thiothrix spp. internally symbiotic with marine invertebrates.

  19. Improving File System Performance by Striping

    NASA Technical Reports Server (NTRS)

    Lam, Terance L.; Kutler, Paul (Technical Monitor)

    1998-01-01

    This document discusses the performance and advantages of striped file systems on the SGI AD workstations. Performance of several striped file system configurations are compared and guidelines for optimal striping are recommended.

  20. Improved traveling wave tubes. [for ECM systems

    NASA Technical Reports Server (NTRS)

    Buck, E.

    1980-01-01

    Techniques, pioneered by NASA, which will allow substantial improvements in traveling wave tube (TWT) amplifier efficiency, are described. It is shown that using design techniques developed at the Lewis Research Center, it is possible to approximately double the efficiency of the critical amplifier TWT. Attention is given to a quick method of computing the expected improvement to an ECM TWT. The benefits of such improvements such as less input power, a smaller and lighter power supply, and easier cooling are surveyed, and it noted that it is now possible to build efficient TWT's which rather than operating at saturation, can be very linear amplifiers. Finally, a new approach to power supplies is also covered.

  1. Performance improvement integration: a whole systems approach.

    PubMed

    Page, C K

    1999-02-01

    Performance improvement integration in health care organizations is a challenge for health care leaders. Required for accreditation by the Joint Commission on Accreditation of Healthcare Organizations (Joint Commission), performance improvement (PI) can be designed as a sustainable model for performance to survive in a turbulent period. Central Baptist Hospital developed a model for PI that focused on strategy established by the leadership team, delineated responsibility through the organizational structure of shared governance, and accountability for outcomes evidenced through the organization's profitability. Such an approach integrated into the culture of the organization can produce positive financial margins, positive customer satisfaction, and commendations from the Joint Commission. PMID:9926679

  2. Milwaukee Laboratory System Improvement Program (L-SIP)

    PubMed Central

    Bhattacharyya, Sanjib; Murphy, Amy; Becker, Julie N.; Baker, Bevan K.

    2013-01-01

    The Laboratory System Improvement Program (L-SIP) of the Association of Public Health Laboratories aims to improve state public health laboratory (PHL) system performance through continuous quality improvement. We successfully applied this state assessment tool to a local PHL (LPHL) system by tailoring it to reflect local system needs and created an LPHL system definition explaining how a local system differs from, yet complements, a state system. On November 18, 2010, 75 stakeholders from 40 agencies assessed the Milwaukee, Wisconsin, PHL system, capturing themes, strengths and weaknesses of the system, and scores for each of the 10 Essential Public Health Services. A Laboratory Advisory Committee analyzed assessment results to identify a strategic focus of research and workforce development and define an action plan, which is now being carried out. Milwaukee's L-SIP process is effectively improving LPHL system research and workforce development while raising community awareness of the system. PMID:23997302

  3. Milwaukee Laboratory System Improvement Program (L-SIP).

    PubMed

    Gradus, M Stephen; Bhattacharyya, Sanjib; Murphy, Amy; Becker, Julie N; Baker, Bevan K

    2013-01-01

    The Laboratory System Improvement Program (L-SIP) of the Association of Public Health Laboratories aims to improve state public health laboratory (PHL) system performance through continuous quality improvement. We successfully applied this state assessment tool to a local PHL (LPHL) system by tailoring it to reflect local system needs and created an LPHL system definition explaining how a local system differs from, yet complements, a state system. On November 18, 2010, 75 stakeholders from 40 agencies assessed the Milwaukee, Wisconsin, PHL system, capturing themes, strengths and weaknesses of the system, and scores for each of the 10 Essential Public Health Services. A Laboratory Advisory Committee analyzed assessment results to identify a strategic focus of research and workforce development and define an action plan, which is now being carried out. Milwaukee's L-SIP process is effectively improving LPHL system research and workforce development while raising community awareness of the system. PMID:23997302

  4. Symbiotic fungal associations in 'lower' land plants.

    PubMed Central

    Read, D J; Ducket, J G; Francis, R; Ligron, R; Russell, A

    2000-01-01

    An analysis of the current state of knowledge of symbiotic fungal associations in 'lower' plants is provided. Three fungal phyla, the Zygomycota, Ascomycota and Basidiomycota, are involved in forming these associations, each producing a distinctive suite of structural features in well-defined groups of 'lower' plants. Among the 'lower' plants only mosses and Equisetum appear to lack one or other of these types of association. The salient features of the symbioses produced by each fungal group are described and the relationships between these associations and those formed by the same or related fungi in 'higher' plants are discussed. Particular consideration is given to the question of the extent to which root fungus associations in 'lower' plants are analogous to 'mycorrhizas' of 'higher' plants and the need for analysis of the functional attributes of these symbioses is stressed. Zygomycetous fungi colonize a wide range of extant lower land plants (hornworts, many hepatics, lycopods, Ophioglossales, Psilotales and Gleicheniaceae), where they often produce structures analogous to those seen in the vesicular-arbuscular (VA) mycorrhizas of higher plants, which are formed by members of the order Glomales. A preponderance of associations of this kind is in accordance with palaeohbotanical and molecular evidence indicating that glomalean fungi produced the archetypal symbioses with the first plants to emerge on to land. It is shown, probably for the first time, that glomalean fungi forming typical VA mycorrhiza with a higher plant (Plantago lanceolata) can colonize a thalloid liverwort (Pellia epiphylla), producing arbuscules and vesicles in the hepatic. The extent to which these associations, which are structurally analogous to mycorrhizas, have similar functions remains to be evaluated. Ascomycetous associations are found in a relatively small number of families of leafy liverworts. The structural features of the fungal colonization of rhizoids and underground axes of

  5. Symbiotic fungal associations in 'lower' land plants.

    PubMed

    Read, D J; Ducket, J G; Francis, R; Ligron, R; Russell, A

    2000-06-29

    An analysis of the current state of knowledge of symbiotic fungal associations in 'lower' plants is provided. Three fungal phyla, the Zygomycota, Ascomycota and Basidiomycota, are involved in forming these associations, each producing a distinctive suite of structural features in well-defined groups of 'lower' plants. Among the 'lower' plants only mosses and Equisetum appear to lack one or other of these types of association. The salient features of the symbioses produced by each fungal group are described and the relationships between these associations and those formed by the same or related fungi in 'higher' plants are discussed. Particular consideration is given to the question of the extent to which root fungus associations in 'lower' plants are analogous to 'mycorrhizas' of 'higher' plants and the need for analysis of the functional attributes of these symbioses is stressed. Zygomycetous fungi colonize a wide range of extant lower land plants (hornworts, many hepatics, lycopods, Ophioglossales, Psilotales and Gleicheniaceae), where they often produce structures analogous to those seen in the vesicular-arbuscular (VA) mycorrhizas of higher plants, which are formed by members of the order Glomales. A preponderance of associations of this kind is in accordance with palaeohbotanical and molecular evidence indicating that glomalean fungi produced the archetypal symbioses with the first plants to emerge on to land. It is shown, probably for the first time, that glomalean fungi forming typical VA mycorrhiza with a higher plant (Plantago lanceolata) can colonize a thalloid liverwort (Pellia epiphylla), producing arbuscules and vesicles in the hepatic. The extent to which these associations, which are structurally analogous to mycorrhizas, have similar functions remains to be evaluated. Ascomycetous associations are found in a relatively small number of families of leafy liverworts. The structural features of the fungal colonization of rhizoids and underground axes of

  6. Healthcare systems engineering: an interdisciplinary approach to achieving continuous improvement.

    PubMed

    Wu, Bin; Klein, Cerry; Stone, Tamara T

    2006-01-01

    This paper argues that a systems approach can significantly enhance healthcare improvement efforts in patient safety, service quality and healthcare cost containment. The application of systems thinking to healthcare improvement encompasses three key principles: the systems perspective of healthcare processes, structured problem solving and the closed loop of continuous system improvement. These are encapsulated in a conceptual framework of continuous system improvement, which includes a reference architecture model and an analysis and design process model. Combined into a closed-loop, this framework allows users to understand and appropriately apply relevant functions, issues and analytical techniques. Practical applications of the framework are presented. PMID:18048245

  7. Effect of Subliminal Stimulation of Symbiotic Fantasies on Behavior Modification Treatment of Obesity.

    ERIC Educational Resources Information Center

    And Others; Silverman, Lloyd H.

    1978-01-01

    Obese women were treated in behavior modification programs for overeating. Behavior programs were accompanied by subliminal stimulation and by symbiotic and control messages. The symbiotic condition gave evidence of enhancing weight loss. This finding supports the proposition that subliminal stimulation of symbiotic fantasies can enhance the…

  8. Improving Student Achievement Using Expert Learning Systems

    ERIC Educational Resources Information Center

    Green, Ronny; Smith, Bob; Leech, Don

    2004-01-01

    Both educators and the public are demanding improvements in student achievement and school performance. However, students meeting the highest college admission standards are increasingly selecting fields of study other than teaching. How can we increase teacher competence when many of our brightest teacher prospects are going into other fields?…

  9. Improving the explanation capabilities of advisory systems

    NASA Technical Reports Server (NTRS)

    Porter, Bruce; Souther, Art

    1994-01-01

    A major limitation of current advisory systems (e.g., intelligent tutoring systems and expert systems) is their restricted ability to give explanations. The goal of our research is to develop and evaluate a flexible explanation facility, one that can dynamically generate responses to questions not anticipated by the system's designers and that can tailor these responses to individual users. To achieve this flexibility, we are developing a large knowledge base, a viewpoint construction facility, and a modeling facility. In the long term we plan to build and evaluate advisory systems with flexible explanation facilities for scientists in numerous domains. In the short term, we are focusing on a single complex domain in biological science, and we are working toward two important milestones: (1) building and evaluating an advisory system with a flexible explanation facility for freshman-level students studying biology, and (2) developing general methods and tools for building similar explanation facilities in other domains.

  10. Improving the explanation capabilities of advisory systems

    NASA Technical Reports Server (NTRS)

    Porter, Bruce; Souther, Art

    1993-01-01

    A major limitation of current advisory systems (e.g., intelligent tutoring systems and expert systems) is their restricted ability to give explanations. The goal of our research is to develop and evaluate a flexible explanation facility, one that can dynamically generate responses to questions not anticipated by the system's designers and that can tailor these responses to individual users. To achieve this flexibility, we are developing a large knowledge base, a viewpoint construction facility, and a modeling facility. In the long term we plan to build and evaluate advisory systems with flexible explanation facilities for scientists in numerous domains. In the short term, we are focusing on a single complex domain in biological science, and we are working toward two important milestones: (1) building and evaluating an advisory system with a flexible explanation facility for freshman-level students studying biology; and (2) developing general methods and tools for building similar explanation facilities in other domains.

  11. The Effect of Symbiotic Supplementation on Liver Enzymes, C-reactive Protein and Ultrasound Findings in Patients with Non-alcoholic Fatty Liver Disease: A Clinical Trial

    PubMed Central

    Asgharian, Atefe; Askari, Gholamreza; Esmailzade, Ahmad; Feizi, Awat; Mohammadi, Vida

    2016-01-01

    Background: Regarding to the growing prevalence of nonalcoholic fatty liver disease (NAFLD), concentrating on various strategies to its prevention and management seems necessary. The aim of this study was to determine the effects of symbiotic on C-reactive protein (CRP), liver enzymes, and ultrasound findings in patients with NAFLD. Methods: Eighty NAFLD patients were enrolled in this randomized, double-blind, placebo-controlled clinical trial. Participants received symbiotic in form of a 500 mg capsule (containing seven species of probiotic bacteria and fructooligosaccharides) or a placebo capsule daily for 8 weeks. Ultrasound grading, CRP, and liver enzymes were evaluated at the baseline and the end of the study. Results: In the symbiotic group, ultrasound grade decreased significantly compared to baseline (P < 0.005) but symbiotic supplementation was not associated with changes in alanine aminotransferase (ALT) and aspartate transaminase (AST) levels. In the placebo group, there was no significant change in steatosis grade whereas ALT and AST levels were significantly increased (P = 0.002, P = 0.02, respectively). CRP values remained static in either group. Conclusions: Symbiotic supplementation improved steatosis in NAFLD patients and might be useful in the management of NAFLD or protective against its progression. PMID:27076897

  12. IPHAS and the symbiotic stars . II. New discoveries and a sample of the most common mimics

    NASA Astrophysics Data System (ADS)

    Corradi, R. L. M.; Valentini, M.; Munari, U.; Drew, J. E.; Rodríguez-Flores, E. R.; Viironen, K.; Greimel, R.; Santander-García, M.; Sabin, L.; Mampaso, A.; Parker, Q.; DePew, K.; Sale, S. E.; Unruh, Y. C.; Vink, J. S.; Rodríguez-Gil, P.; Barlow, M. J.; Lennon, D. J.; Groot, P. J.; Giammanco, C.; Zijlstra, A. A.; Walton, N. A.

    2010-01-01

    Context. Knowledge of the total population of symbiotic stars in the Galaxy is important for understanding basic aspects of stellar evolution in interacting binaries and the relevance of this class of objects in the formation of supernovae of type Ia. Aims: In a previous paper, we presented the selection criteria needed to search for symbiotic stars in IPHAS, the INT Hα survey of the Northern Galactic plane. IPHAS gives us the opportunity to make a systematic, complete search for symbiotic stars in a magnitude-limited volume. Methods: Follow-up spectroscopy at different telescopes worldwide of a sample of sixty two symbiotic star candidates is presented. Results: Seven out of nineteen S-type candidates observed spectroscopically are confirmed to be genuine symbiotic stars. The spectral type of their red giant components, as well as reddening and distance, were computed by modelling the spectra. Only one new D-type symbiotic system, out of forty-three candidates observed, was found. This was as expected (see discussion in our paper on the selection criteria). The object shows evidence for a high density outflow expanding at a speed ≥65 km s-1. Most of the other candidates are lightly reddened classical T Tauri stars and more highly reddened young stellar objects that may be either more massive young stars of HAeBe type or classical Be stars. In addition, a few notable objects have been found, such as three new Wolf-Rayet stars and two relatively high-luminosity evolved massive stars. We also found a helium-rich source, possibly a dense ejecta hiding a WR star, which is surrounded by a large ionized nebula. Conclusions: These spectroscopic data allow us to refine the selection criteria for symbiotic stars in the IPHAS survey and, more generally, to better understand the behaviour of different Hα emitters in the IPHAS and 2MASS colour-colour diagrams. Based on observations obtained at; the 2.6 m Nordic Optical Telescope operated by NOTSA; the 2.5 m INT and 4.2 m

  13. Film processing investigation. [improved chemical mixing system

    NASA Technical Reports Server (NTRS)

    Kelly, J. L.

    1972-01-01

    The present operational chemical mixing system for the Photographic Technology Division is evaluated, and the limitations are defined in terms of meeting the present and programmed chemical supply and delivery requirements. A major redesign of the entire chemical mixing, storage, analysis, and supply system is recommended. Other requirements for immediate and future implementations are presented.

  14. Feedback Improvement in Automatic Program Evaluation Systems

    ERIC Educational Resources Information Center

    Skupas, Bronius

    2010-01-01

    Automatic program evaluation is a way to assess source program files. These techniques are used in learning management environments, programming exams and contest systems. However, use of automated program evaluation encounters problems: some evaluations are not clear for the students and the system messages do not show reasons for lost points.…

  15. Changing and Improving Educational Systems and Institutions.

    ERIC Educational Resources Information Center

    Thomas, A. Ross

    Research into the process of educational change has centered largely around the diffusion concept--the spread or permeation of an innovation from system to system or from school to school throughout a particular state or number of states. It is as if many teachers and administrators have understood the purpose of educational change to be the…

  16. Reliability improvement of distribution systems using SSVR.

    PubMed

    Hosseini, Mehdi; Shayanfar, Heidar Ali; Fotuhi-Firuzabad, Mahmoud

    2009-01-01

    This paper presents a reliability assessment algorithm for distribution systems using a Static Series Voltage Regulator (SSVR). Furthermore, this algorithm considers the effects of Distributed Generation (DG) units, alternative sources, system reconfiguration, load shedding and load adding on distribution system reliability indices. In this algorithm, load points are classified into 8 types and separated restoration times are considered for each class. Comparative studies are conducted to investigate the impacts of DG and alternative source unavailability on the distribution system reliability. For reliability assessment, the customer-oriented reliability indices such as SAIFI, SAIDI, CAIDI ASUI and also load- and energy-oriented indices such as ENS and AENS are evaluated. The effectiveness of the proposed algorithm is examined on the two standard distribution systems consisting of 33 and 69 nodes. The best location of the SSVR in distribution systems is determined based on different reliability indices, separately. Results show that the proposed algorithm is efficient for large-scale radial distribution systems and can accommodate the effects of fault isolation and load restoration. PMID:19006802

  17. Improved Large-Field Focusing Schlieren System

    NASA Technical Reports Server (NTRS)

    Weinstein, Leonard M.

    1993-01-01

    System used to examine complicated two- and three-dimensional flows. High-brightness large-field focusing schlieren system incorporates Fresnel lens instead of glass diffuser. In system with large field of view, image may also be very large. Relay optical subsystem minifies large image while retaining all of light. Facilities candidates for use of focusing schlieren include low-speed wind and water tunnels. Heated or cooled flow tracers or injected low- or high-density tracers used to make flows visible for photographic recording.

  18. Designing Bioretention Systems to Improve Nitrogen Removal

    EPA Science Inventory

    Bioretention systems effectively remove many stormwater stressors, including oil/grease, heavy metals, phosphorus, and ammonium. However, reported nitrate removal performance is highly variable. Bioretention media is typically coarse-grained with low organic matter content, which...

  19. Improving pumping system efficiency at coal plants

    SciTech Connect

    Livoti, W.C.; McCandless, S.; Poltorak, R.

    2009-03-15

    The industry must employ ultramodern technologies when building or upgrading power plant pumping systems thereby using fuels more efficiently. The article discusses the uses and efficiencies of positive displacement pumps, centrifugal pumps and multiple screw pumps. 1 ref., 4 figs.

  20. How regional trauma systems improve outcomes.

    PubMed

    Cole, Elaine

    2015-10-01

    Management of severely injured patients is complex and requires organised, expert care. Regionalised trauma systems are relatively new in the UK and aim to deliver optimal, timely care to injured patients at the most appropriate location. This article discusses the drivers, organisation, processes and outcomes of regionalised trauma care. It also describes the challenges and benefits of working within a trauma system to enable emergency practitioners to reflect on their roles in contemporary trauma care. PMID:26451941

  1. Improved Dichroics For Microwave Reflector Antenna Systems

    NASA Technical Reports Server (NTRS)

    Wu, Te-Kao

    1995-01-01

    Panel contains array of grid and square conductive loops as array elements designed to reflect most of incident electromagnetic radiation in K(subu) band (13.5 to 15.5 GHz) and to pass that in X band (7 to 9 GHz). Designed to exhibit this dichroic property at angles of incidence up to 40 degrees in transverse electric, transverse magnetic, or circular polarization. Concept of gridded-square-loop dichroic array related to double-loop dichroic arrays described in "Frequency-Selective Microwave Reflectors" (NPO-18701). Improved version exhibits smaller shift of resonant frequency with angle of incidence.

  2. Multiresponse imaging system design for improved resolution

    NASA Technical Reports Server (NTRS)

    Alter-Gartenberg, Rachel; Fales, Carl L.; Huck, Friedrich O.; Rahman, Zia-Ur; Reichenbach, Stephen E.

    1991-01-01

    Multiresponse imaging is a process that acquires A images, each with a different optical response, and reassembles them into a single image with an improved resolution that can approach 1/sq rt A times the photodetector-array sampling lattice. Our goals are to optimize the performance of this process in terms of the resolution and fidelity of the restored image and to assess the amount of information required to do so. The theoretical approach is based on the extension of both image restoration and rate-distortion theories from their traditional realm of signal processing to image processing which includes image gathering and display.

  3. Systems and methods for improved telepresence

    DOEpatents

    Anderson, Matthew O.; Willis, W. David; Kinoshita, Robert A.

    2005-10-25

    The present invention provides a modular, flexible system for deploying multiple video perception technologies. The telepresence system of the present invention is capable of allowing an operator to control multiple mono and stereo video inputs in a hands-free manner. The raw data generated by the input devices is processed into a common zone structure that corresponds to the commands of the user, and the commands represented by the zone structure are transmitted to the appropriate device. This modularized approach permits input devices to be easily interfaced with various telepresence devices. Additionally, new input devices and telepresence devices are easily added to the system and are frequently interchangeable. The present invention also provides a modular configuration component that allows an operator to define a plurality of views each of which defines the telepresence devices to be controlled by a particular input device. The present invention provides a modular flexible system for providing telepresence for a wide range of applications. The modularization of the software components combined with the generalized zone concept allows the systems and methods of the present invention to be easily expanded to encompass new devices and new uses.

  4. Nodulation outer proteins: double-edged swords of symbiotic rhizobia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizobia are nitrogen-fixing bacteria that establish a nodule symbiosis with legumes. Nodule formation is the result of a complex bacterial infection process, which depends on signals and surface determinants produced by both symbiotic partners. Among them, rhizobial nodulation outer proteins (Nops)...

  5. The prototype symbiotic star AX Per is in outburst

    NASA Astrophysics Data System (ADS)

    Munari, U.; Dallaporta, S.; Righetti, G. L.; Castellani, F.; Cherini, G.

    2014-08-01

    The prototype symbiotic star AX Per is in outburst. This is the third such event in the current series of outbursts, the previous two peaking at V=10.41 on 2009 May 26 and at V=10.03 on 2012 Aug 28, according to ANS Collaboration intensive monitoring.

  6. Improved OTEC System for a Submarine Robot

    NASA Technical Reports Server (NTRS)

    Chao, Yi; Jones, Jack; Valdez, Thomas

    2010-01-01

    An ocean thermal energy conversion (OTEC), now undergoing development, is a less-massive, more-efficient means of exploiting the same basic principle as that of the proposed system described in "Alternative OTEC Scheme for a Submarine Robot" (NPO-43500), NASA Tech Briefs, Vol. 33, No. 1 (January 2009), page 50. The proposed system as described previously would be based on the thawing-expansion/freezing-contraction behavior of a wax or perhaps another suitable phase-change material (PCM). The power generated by the system would be used to recharge the batteries in a battery- powered unmanned underwater vehicle [UUV (essentially, a small exploratory submarine robot)] of a type that has been deployed in large numbers in research pertaining to global warming. A UUV of this type travels between the ocean surface and depths, measuring temperature and salinity. At one phase of its operational cycle, the previously proposed system would utilize the surface ocean temperature (which lies between 15 and 30 C over most of the Earth) to melt a PCM that has a melting/freezing temperature of about 10 C. At the opposite phase of its operational cycle, the system would utilize the lower ocean temperature at depth (e.g., between 4 and 7 C at a depth of 300 m) to freeze the PCM. The melting or freezing would cause the PCM to expand or contract, respectively, by about 9 volume percent. The PCM would be contained in tubes that would be capable of expanding and contracting with the PCM. The PCM-containing tubes would be immersed in a hydraulic fluid. The expansion and contraction would drive a flow of the hydraulic fluid against a piston that, in turn, would push a rack-and-pinion gear system to spin a generator to charge a battery.

  7. Improving Fan System Performance: A Sourcebook for Industry

    SciTech Connect

    2003-04-01

    This is one of a series of sourcebooks on motor-driven equipment produced by the Industrial Technologies Program. It provides a reference for industrial fan systems users, outlining opportunities to improve fan system performance.

  8. Improving Compressed Air System Performance: A Sourcebook for Industry

    SciTech Connect

    2003-11-01

    NREL will produce this sourcebook for DOE's Industrial Technologies Office as part of a series of documents on industrial energy equipment. The sourcebook is a reference for industrial compressed air system users, outlining opportunities to improve system efficiency.

  9. Corporate Electronic Publishing Systems. Curriculum Improvement Project.

    ERIC Educational Resources Information Center

    Courtney, Dwight; Crowley, Ed

    This guide is intended for use in teaching a postsecondary-level course in corporate electronic publishing systems. The following topics are covered: cultural influence of graphic communication (early events in communication, early attempts at printing); typefaces and styles of type (type style characteristics and their use); tools and methods of…

  10. Designing Coherent Education Policy: Improving the System.

    ERIC Educational Resources Information Center

    Fuhrman, Susan H., Ed.

    This book examines issues in designing coherent education policy for public elementary and secondary schools. It seeks to expand the policy discussion by refining the definition of coherence and considering a number of complex questions raised by the notion of coherent policy. The book offers an in-depth look at systemic school reform and offers a…

  11. Philadelphia's Teacher Appraisal System Needs Improvement

    ERIC Educational Resources Information Center

    Royal, Camika; Tossman, Matthew

    2009-01-01

    The purpose of this paper is to inform the community about teacher appraisal methods in the School District of Philadelphia, outline the difficulties of the current system, and suggest approaches that would strengthen the teacher appraisal process. The authors gathered their information over three months in mid-2009 from multiple sources:…

  12. Operating Systems. Curriculum Improvement Project. Region II.

    ERIC Educational Resources Information Center

    Wagstaff, Charlene

    This course curriculum is intended for community college instructors and administrators to use in implementing an operating systems course. A student's course syllabus provides this information: credit hours, catalog description, prerequisites, required texts, instructional process, objectives, student evaluation, and class schedule. A student…

  13. Heat pump having improved defrost system

    DOEpatents

    Chen, Fang C.; Mei, Viung C.; Murphy, Richard W.

    1998-01-01

    A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger.

  14. Supporting Continuous Improvement in California's Education System

    ERIC Educational Resources Information Center

    Darling-Hammond, Linda; Plank, David N.

    2015-01-01

    California's new accountability system originated in the radical decentralization of power and authority from Sacramento to local schools and their communities brought about by the Legislature's adoption of the Local Control Funding Formula (LCFF) in 2013. Under California's previous accountability policies and the federal "No Child Left…

  15. Improved thermal isolation for superconducting magnet systems

    NASA Technical Reports Server (NTRS)

    Wiebe, E. R.

    1974-01-01

    Closed-cycle refrigerating system for superconductive magnet and maser is operated in vacuum environment. Each wire leading from external power source passes through cooling station which blocks heat conduction. In connection with these stations, switch with small incandescent light bulb, which generates heat, is used to stop superconduction.

  16. The Symbiotic Relationship between Scientific Workflow and Provenance (Invited)

    NASA Astrophysics Data System (ADS)

    Stephan, E.

    2010-12-01

    The purpose of this presentation is to describe the symbiotic nature of scientific workflows and provenance. We will also discuss the current trends and real world challenges facing these two distinct research areas. Although motivated differently, the needs of the international science communities are the glue that binds this relationship together. Understanding and articulating the science drivers to these communities is paramount as these technologies evolve and mature. Originally conceived for managing business processes, workflows are now becoming invaluable assets in both computational and experimental sciences. These reconfigurable, automated systems provide essential technology to perform complex analyses by coupling together geographically distributed disparate data sources and applications. As a result, workflows are capable of higher throughput in a shorter amount of time than performing the steps manually. Today many different workflow products exist; these could include Kepler and Taverna or similar products like MeDICI, developed at PNNL, that are standardized on the Business Process Execution Language (BPEL). Provenance, originating from the French term Provenir “to come from”, is used to describe the curation process of artwork as art is passed from owner to owner. The concept of provenance was adopted by digital libraries as a means to track the lineage of documents while standards such as the DublinCore began to emerge. In recent years the systems science community has increasingly expressed the need to expand the concept of provenance to formally articulate the history of scientific data. Communities such as the International Provenance and Annotation Workshop (IPAW) have formalized a provenance data model. The Open Provenance Model, and the W3C is hosting a provenance incubator group featuring the Proof Markup Language. Although both workflows and provenance have risen from different communities and operate independently, their mutual

  17. Fly ash system technology improves opacity

    SciTech Connect

    2007-06-15

    Unit 3 of the Dave Johnston Power Plant east of Glenrock, WY, USA had problems staying at or below the opacity limits set by the state. The unit makes use of a Lodge Cottrell precipitator. When the plant changed to burning Power River Basin coal, ash buildup became a significant issue as the fly ash control system was unable to properly evacuate hoppers on the unit. To overcome the problem, the PLC on the unit was replaced with a software optimization package called SmartAsh for the precipitator fly ash control system, at a cost of $500,000. After the upgrade, there have been no plugged hoppers and the opacity has been reduced from around 20% to 3-5%. 2 figs.

  18. Imaging system design for improved information capacity

    NASA Technical Reports Server (NTRS)

    Fales, C. L.; Huck, F. O.; Samms, R. W.

    1984-01-01

    Shannon's theory of information for communication channels is used to assess the performance of line-scan and sensor-array imaging systems and to optimize the design trade-offs involving sensitivity, spatial response, and sampling intervals. Formulations and computational evaluations account for spatial responses typical of line-scan and sensor-array mechanisms, lens diffraction and transmittance shading, defocus blur, and square and hexagonal sampling lattices.

  19. Magnetic Bearing Controller Improvements for High Speed Flywheel System

    NASA Technical Reports Server (NTRS)

    Dever, Timothy P.; Brown, Gerald V.; Jansen, Ralph H.; Kascak, Peter E.; Provenza, Andrew J.

    2003-01-01

    A magnetic bearing control system for a high-speed flywheel system is described. The flywheel utilizes a five axis active magnetic bearing system, using eddy current sensors for position feedback to the bearing controller. Magnetic bearing controller features designed to improve flywheel operation and testing are described. Operational improvements include feed forward control to compensate for rotor imbalance, moving notch filtering to compensate for synchronous and harmonic rotational noise, and fixed notching to prevent rotor bending mode excitation. Testing improvements include adding safe gain, bearing current hold, bearing current zero, and excitation input features. Performance and testing improvements provided by these features are measured and discussed.

  20. Improving School Leadership. Volume 2: Case Studies on System Leadership

    ERIC Educational Resources Information Center

    Hopkins, David, Ed.; Nusche, Deborah, Ed.; Pont, Beatriz, Ed.

    2008-01-01

    This book explores what specialists are saying about system leadership for school improvement. Case studies examine innovative approaches to sharing leadership across schools in Belgium (Flanders), Finland and the United Kingdom (England) and leadership development programmes for system improvement in Australia and Austria. As these are emerging…

  1. Chemical abundance analysis of symbiotic giants - I. RW Hya and SY Mus

    NASA Astrophysics Data System (ADS)

    Mikołajewska, Joanna; Gałan, Cezary; Hinkle, Kenneth H.; Gromadzki, Mariusz; Schmidt, Mirosław R.

    2014-06-01

    The study of symbiotic systems is of considerable importance in our understanding of binary system stellar evolution in systems where mass-loss or transfer takes place. Elemental abundances are of special significance since they can be used to track mass exchange. However, there are few symbiotic giants for which the abundances are fairly well determined. Here, we present for the first time a detailed analysis of the chemical composition for the giants in the RW Hya and SY Mus systems. The analysis is based on high-resolution (R ˜ 50 000), high signal-to-noise (S/N), near-IR spectra. Spectrum synthesis employing standard local thermal equilibrium (LTE) analysis and atmosphere models was used to obtain photospheric abundances of CNO and elements around the iron peak (Sc, Ti, Fe, and Ni). Our analysis reveals a significantly sub-solar metallicity, [Fe/H] ˜ -0.75, for the RW Hya giant confirming its membership in the Galactic halo population and a near-solar metallicity for the SY Mus giant. The very low 12C/13C isotopic ratios, ˜6-10, derived for both objects indicate that the giants have experienced the first dredge-up.

  2. Soybean nodulation and symbiotic nitrogen fixation in response to soil compaction and mulching

    NASA Astrophysics Data System (ADS)

    Siczek, A.; Lipiec, J.

    2009-04-01

    Symbiotic nitrogen fixation by legume crops such as soybean plays a key role in supplying nitrogen for agricultural systems. In symbiotic associations with Bradyrhizobium japonicum soybean can fix up to 200 kg N ha-1 yr-1. This reduces the need for expensive and often environmentally harmful because of leaching nitrogen fertilization. However both soybean nodulation and nitrogen fixation are sensitive to soil conditions. One of the critical soil constraints is soil compaction. Increasing use of heavy equipment and intensive cropping in modern agriculture leads to excessive soil compaction. Compaction often is found as a result of field operations that have to be performed in a very short period of time and when soils are wet and more susceptible to compaction. This results in unfavourable water content, temperature, aeration, pore size distribution, strength for plant growth and microbial activity. The surface mulching can alleviate the adverse effect of the environmental factors on soil by decreasing fluctuation of soil temperature, increasing moisture by controlling evaporation from the soil surface, decreasing bulk density, preventing soil crusting. The effect of mulch on soil conditions largely depends on soil compaction and weather conditions during growing season. The positive effect of the straw mulch on soil moisture has been seen under seasons with insufficient rainfalls. However thicker layers of mulch can act as diffusion barrier, especially when the mulch is wet. Additionally, low soil temperature prevalent during early spring under mulch can impede development of nodule, nodule size and delay onset of nodulation. The aim of this study was to determine the effect of the straw mulch on nodulation and nitrogen fixation of soybean in variously compacted soil. The experimental field was 192 m2and was divided into three parts composed of 6 micro-plots with area 7 m2. Three degrees of soil compaction obtained in each field part through tractor passes were

  3. Rotary Mode Core Sample System availability improvement

    SciTech Connect

    Jenkins, W.W.; Bennett, K.L.; Potter, J.D.; Cross, B.T.; Burkes, J.M.; Rogers, A.C.

    1995-02-28

    The Rotary Mode Core Sample System (RMCSS) is used to obtain stratified samples of the waste deposits in single-shell and double-shell waste tanks at the Hanford Site. The samples are used to characterize the waste in support of ongoing and future waste remediation efforts. Four sampling trucks have been developed to obtain these samples. Truck I was the first in operation and is currently being used to obtain samples where the push mode is appropriate (i.e., no rotation of drill). Truck 2 is similar to truck 1, except for added safety features, and is in operation to obtain samples using either a push mode or rotary drill mode. Trucks 3 and 4 are now being fabricated to be essentially identical to truck 2.

  4. Concurrent hypercube system with improved message passing

    NASA Technical Reports Server (NTRS)

    Peterson, John C. (Inventor); Tuazon, Jesus O. (Inventor); Lieberman, Don (Inventor); Pniel, Moshe (Inventor)

    1989-01-01

    A network of microprocessors, or nodes, are interconnected in an n-dimensional cube having bidirectional communication links along the edges of the n-dimensional cube. Each node's processor network includes an I/O subprocessor dedicated to controlling communication of message packets along a bidirectional communication link with each end thereof terminating at an I/O controlled transceiver. Transmit data lines are directly connected from a local FIFO through each node's communication link transceiver. Status and control signals from the neighboring nodes are delivered over supervisory lines to inform the local node that the neighbor node's FIFO is empty and the bidirectional link between the two nodes is idle for data communication. A clocking line between neighbors, clocks a message into an empty FIFO at a neighbor's node and vica versa. Either neighbor may acquire control over the bidirectional communication link at any time, and thus each node has circuitry for checking whether or not the communication link is busy or idle, and whether or not the receive FIFO is empty. Likewise, each node can empty its own FIFO and in turn deliver a status signal to a neighboring node indicating that the local FIFO is empty. The system includes features of automatic message rerouting, block message transfer and automatic parity checking and generation.

  5. Lean management systems: creating a culture of continuous quality improvement.

    PubMed

    Clark, David M; Silvester, Kate; Knowles, Simon

    2013-08-01

    This is the first in a series of articles describing the application of Lean management systems to Laboratory Medicine. Lean is the term used to describe a principle-based continuous quality improvement (CQI) management system based on the Toyota production system (TPS) that has been evolving for over 70 years. Its origins go back much further and are heavily influenced by the work of W Edwards Deming and the scientific method that forms the basis of most quality management systems. Lean has two fundamental elements--a systematic approach to process improvement by removing waste in order to maximise value for the end-user of the service and a commitment to respect, challenge and develop the people who work within the service to create a culture of continuous improvement. Lean principles have been applied to a growing number of Healthcare systems throughout the world to improve the quality and cost-effectiveness of services for patients and a number of laboratories from all the pathology disciplines have used Lean to shorten turnaround times, improve quality (reduce errors) and improve productivity. Increasingly, models used to plan and implement large scale change in healthcare systems, including the National Health Service (NHS) change model, have evidence-based improvement methodologies (such as Lean CQI) as a core component. Consequently, a working knowledge of improvement methodology will be a core skill for Pathologists involved in leadership and management. PMID:23757036

  6. Can Quality Improvement System Improve Childcare Site Performance in School Readiness?

    ERIC Educational Resources Information Center

    Ma, Xin; Shen, Jianping; Lu, Xuejin; Brandi, Karen; Goodman, Jeff; Watson, Grace

    2013-01-01

    The authors evaluated the effectiveness of the Quality Improvement System (QIS) developed and implemented by Children's Services Council of Palm Beach County (Florida) as a voluntary initiative to improve the quality of childcare and education. They adopted a growth model approach to investigate whether childcare sites that participated in…

  7. Systems Thinking: A Skill to Improve Student Achievement

    ERIC Educational Resources Information Center

    Thornton, Bill; Peltier, Gary; Perreault, George

    2004-01-01

    This article examines how schools can avoid barriers to systems thinking in relation to improving student achievement. It then illustrates common errors associated with non-systems thinking and recommends solutions. Educators who understand that schools are complex interdependent social systems can move their organizations forward. Unfortunately,…

  8. Achieving Continuous Improvement: Theories that Support a System Change.

    ERIC Educational Resources Information Center

    Armel, Donald

    Focusing on improvement is different than focusing on quality, quantity, customer satisfaction, and productivity. This paper discusses Open System Theory, and suggests ways to change large systems. Changing a system (meaning the way all the parts are connected) requires a considerable amount of data gathering and analysis. Choosing the proper…

  9. Validation of a National Teacher Assessment and Improvement System

    ERIC Educational Resources Information Center

    Taut, Sandy; Santelices, Maria Veronica; Stecher, Brian

    2012-01-01

    The task of validating a teacher assessment and improvement system is similar whether the system operates in the United States or in another country. Chile has a national teacher evaluation system (NTES) that is standards based, uses multiple instruments, and is intended to serve both formative and summative purposes. For the past 6 years the…

  10. LMC S63: a historical reappraisal of the outburst behaviour of a deeply eclipsing Magellanic symbiotic star

    NASA Astrophysics Data System (ADS)

    Iłkiewicz, Krystian; Mikołajewska, Joanna; Miszalski, Brent; Gromadzki, Mariusz; Whitelock, Patricia A.

    2015-08-01

    We present an analysis of multi-epoch low-resolution spectrophotometry, complemented by the light curves provided by massive photometric surveys spanning over 100 yr, of the symbiotic binary LMC S63. We showed that it is an eclipsing binary with the orbital period of 1050 d. We also found evidence of outbursts in history of the white dwarf. If it was a Z And-type outburst, as is most likely, it would be a second such outburst recorded in the Magellanic Cloud symbiotic system. We confirmed that the red giant is enhanced in carbon, and estimated C/O ≃ 1.2 by fitting a model atmosphere to the Southern African Large Telescope (SALT) spectrum. We also found bi-periodic pulsations of the red giant, and demonstrated that it is similar to other carbon variables with confirmed bi-periodicity.

  11. Ultraviolet observations of the symbiotic star AS 296

    NASA Technical Reports Server (NTRS)

    Gutierrez-Moreno, A.; Moreno, H.; Feibelman, W. A.

    1992-01-01

    AS 296 is a well-known S-type symbiotic star which underwent an optical outburst during 1988. In this paper, UV data based on IUE observations obtained both during the quiescent and outburst stages are presented and discussed, correlating them to observations made in the optical region. It is concluded that the object is a symbiotic nova, in which the outburst is due to a thermonuclear runaway produced in the hydrogen-burning shell of a white dwarf with M of about 0.5 solar masses, accreting from the late-type giant at a rate M(acc) of about 9.7 x 10 exp -9 solar mass/year. It is not possible to determine from the observations if the hydrogen flash is degenerate or nondegenerate.

  12. Evolution of the plant-microbe symbiotic 'toolkit'.

    PubMed

    Delaux, Pierre-Marc; Séjalon-Delmas, Nathalie; Bécard, Guillaume; Ané, Jean-Michel

    2013-06-01

    Beneficial associations between plants and arbuscular mycorrhizal fungi play a major role in terrestrial environments and in the sustainability of agroecosystems. Proteins, microRNAs, and small molecules have been identified in model angiosperms as required for the establishment of arbuscular mycorrhizal associations and define a symbiotic 'toolkit' used for other interactions such as the rhizobia-legume symbiosis. Based on recent studies, we propose an evolutionary framework for this toolkit. Some components appeared recently in angiosperms, whereas others are highly conserved even in land plants unable to form arbuscular mycorrhizal associations. The exciting finding that some components pre-date the appearance of arbuscular mycorrhizal fungi suggests the existence of unknown roles for this toolkit and even the possibility of symbiotic associations in charophyte green algae. PMID:23462549

  13. Leguminous plants: inventors of root nodules to accommodate symbiotic bacteria.

    PubMed

    Suzaki, Takuya; Yoro, Emiko; Kawaguchi, Masayoshi

    2015-01-01

    Legumes and a few other plant species can establish a symbiotic relationship with nitrogen-fixing rhizobia, which enables them to survive in a nitrogen-deficient environment. During the course of nodulation, infection with rhizobia induces the dedifferentiation of host cells to form primordia of a symbiotic organ, the nodule, which prepares plants to accommodate rhizobia in host cells. While these nodulation processes are known to be genetically controlled by both plants and rhizobia, recent advances in studies on two model legumes, Lotus japonicus and Medicago truncatula, have provided great insight into the underlying plant-side molecular mechanism. In this chapter, we review such knowledge, with particular emphasis on two key processes of nodulation, nodule development and rhizobial invasion. PMID:25805123

  14. Ant-plant mutualisms should be viewed as symbiotic communities

    PubMed Central

    Bouamer, Salah; Morand, Serge; Selosse, Marc-André

    2009-01-01

    Ant-plants provide food and nesting space (domatia) for ants that protect them against herbivores. These mutualisms are often very specific and are usually considered as bipartite, or tripartite when ants use hemipterans as trophobionts. However, fungi growing inside domatia have been recorded by a few authors. Here we report on their occurrence on additional ant-plants from Africa, Asia and South America. We demonstrated the symbiotic nature of the relationship between the plant, the ant and the fungus in the model plant Leonardoxa africana africana and its mutualistic ant Petalomyrmex phylax. Moreover, data suggest the ant-fungus relationship is mutualistic. Here we discuss the most probable role of the fungus and the potential implications on the understanding of nutritional ecology of ant-plant symbioses. The fungus is also associated with the presence of nematodes and bacteria. Many ant-plant symbioses previously considered to be bipartite will soon likely prove to be multipartite symbiotic communities. PMID:19816123

  15. Spectrophotometric observations of symbiotic stars and related objects

    NASA Technical Reports Server (NTRS)

    Blair, W. P.; Feibelman, W. A.; Michalitsianos, A. G.; Stencel, R. E.

    1983-01-01

    Calibrated optical spectrophotometric observations of 16 symbiotic and symbiotic-like objects are presented. The objects observed include Z And, T CrB, CH Cyg, CI Cyg, V1016 Cyg, V1329 Cyg, AG Dra, YY Her, RS Oph, XX Oph, AG Peg, AX Per, CL Sco, HM Sge, AS 289, and M1-2. Integrated emission-line intensities are tabulated for comparison with ultraviolet and infrared data, as well as with previous optical studies. The reddening to each of the objects is derived by assuming that Balmer lines are emitted in their case B recombination ratios. However, the values so derived are often systematically higher than reddening estimates from the ultraviolet 2200 A feature. Comparisons with the available data from other wavelength ranges are noted.

  16. Human system interaction measures: An approach to improve system performance

    SciTech Connect

    Blackman, H.S.

    1990-01-01

    This paper presents an approach for the analysis of system performance. This approach is based upon a functional model of the system, and performance measures of that system. The paper also presents a model of total system performance which is composed of the following three parts: challenges (the challenge represented by the scenario), functions (the resources available to be applied to the challenge), and sequence (how resources are used to cope with the challenge). The approach and model are applied and presented in a civil aviation application. 2 figs.

  17. Sequence evidence for the symbiotic origins of chloroplasts and mitochondria

    NASA Technical Reports Server (NTRS)

    George, D. G.; Hunt, L. T.; Dayhoff, M. O.

    1983-01-01

    The origin of mitochondria and chloroplasts is investigated on the basis of prokaryotic and early-eukaryotic evolutionary trees derived from protein and nucleic-acid sequences by the method of Dayhoff (1979). Trees for bacterial ferrodoxins, 5S ribosomal RNA, c-type cytochromes, the lipid-binding subunit of ATPase, and dihydrofolate reductase are presented and discussed. Good agreement among the trees is found, and it is argued that the mitochondria and chloroplasts evolved by multiple symbiotic events.

  18. Improving State Accountability Systems for Postsecondary Vocational Education.

    ERIC Educational Resources Information Center

    Sheets, Robert G.

    This paper makes recommendations for developing the next generation of state accountability systems for postsecondary vocational education (PVE). It focuses on the need to improve the core indicators for PVE; reduce the burden and improve the value of Carl D. Perkins Vocational and Applied Technology Education Amendments of 1998 (Perkins III)…

  19. A rhizobium leguminosarum mutant defective in symbiotic iron acquisition

    SciTech Connect

    Nadler, K.D.; Chen, Jing-Wen; John, T.R. ); Johnston, A.W.B. )

    1990-02-01

    Iron acquisition by symbiotic Rhizobium spp. is essential for nitrogen fixation in the legume root nodule symbiosis. Rhizobium leguminosarum 116, an ineffective mutant strain with a defect in iron acquisition, was isolated after nitrosoguanidine mutagenesis of the effective strain 1062. The pop-1 mutation in strain 116 imparted to it a complex phenotype, characteristic of iron deficiency. Several iron(III)-solubilizing agents, such as citrate, hydroxyquinoline, and dihydroxybenzoate, stimulated growth of 116 on low-iron solid medium; anthranilic acid, the R. leguminosarum siderophore, inhibited low-iron growth of 116. The initial rate of {sup 55}Fe uptake by suspensions of iron-starved 116 cells was 10-fold less than that of iron-starved wild-type cells. Electron microscopic observations revealed no morphological abnormalities in the small, white nodules induced by 116. Nodule cortical cells were filled with vesicles containing apparently normal bacteroids. No premature degeneration of bacteroids or of plant cell organelles was evident. The authors mapped pop-1 by R plasmid-mediated conjugation and recombination to the ade-27-rib-2 region of the R. leguminosarum chromosome. No segregation of pop-1 and the symbiotic defect was observed among the recombinants from these crosses. Cosmid pKN1, a pLAFR1 derivative containing a 24-kilobase-pair fragment of R. leguminosarum DNA, conferred on 116 the ability to grow on dipyridyl medium and to fix nitrogen symbiotically.

  20. Discovery of collimated ejection from the symbiotic binary BF Cygni

    NASA Astrophysics Data System (ADS)

    Skopal, A.; Tomov, N. A.; Tomova, M. T.

    2013-03-01

    Context. Detection of collimated ejection from white dwarfs (WD) in symbiotic binaries is very rare and has employed a variety of methods in X-ray, radio, optical imagery, and spectroscopy. To date, its signature in the optical spectra has only been recorded for four objects (MWC 560, Hen 3-1341, StHα 190, and Z And). Aims: We present the first observational evidence of highly-collimated bipolar ejection from the symbiotic binary BF Cyg, which developed during its current (2006-12) active phase, and determine their physical parameters. Methods: We monitored the outburst with the optical high-resolution spectroscopy and multicolour UBVRCIC photometry. Results: During 2009, three years after the 2006-eruption of BF Cyg, satellite components to Hα and Hβ lines emerged in the spectrum. During 2012, they became stable and were located symmetrically with respect to the main emission core of the line. Spectral properties of these components suggest bipolar ejection collimated within an opening angle of ≲15°, whose radiation is produced by an optically thin medium with the emission measure of 1-2 × 1059 (d/3.8 kpc)2 cm-3. Conclusions: Formation of the collimated ejection a few years after the eruption and its evolution on a time scale of years at a constant optical brightness can aid us in better understanding the accretion process during the active phases of symbiotic stars. Based on data collected with 2-m telescope at the Rozhen National Astronomical Observatory and the David Dunlap Observatory.

  1. Cellulolytic activity and structure of symbiotic bacteria in locust guts.

    PubMed

    Su, L-J; Liu, H; Li, Y; Zhang, H-F; Chen, M; Gao, X-H; Wang, F-Q; Song, A-D

    2014-01-01

    Locusts are able to digest the cellulose of Gramineae plants, resulting in their being considered as major crop pests. To illustrate the mechanism involved in cellulose digestion, the cellulolytic activity and zymography in the gut contents of 16 locust species were determined using carboxymethyl cellulose (CMC) as substrate. The diversity of gut symbiotic bacteria was studied using denaturing gradient gel electrophoresis (DGGE). The results showed that high CMC activity was present in Acrididae gut fluid (mean 356.4 U/g proteins). Of the 5 locust species, Oxya chinensis had the highest diversity of intestinal symbiotic bacteria, characterized by the DGGE profile containing more than 20 bands of 16S rRNA. Klebsiella pneumoniae, in the gut of Locusta migratoria manilensis, was identified as the most abundant symbiotic bacterium by DNA sequencing, with a relative abundance of 19.74%. In comparison, Methylobacterium sp was the most dominant species in the Atractomorpha sinensis gut, with a relative abundance of 29.04%. The results indicated that the cellulolytic enzymes and gut microbial communities probably reflected their phylogenetic relationship with different locust species and associated feeding strategies. PMID:25299108

  2. Symbiotic regulation of plant growth, development and reproduction

    USGS Publications Warehouse

    Rodriguez, R.J.; Freeman, D. Carl; McArthur, E.D.; Kim, Y.-O.; Redman, R.S.

    2009-01-01

    The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at five times the rate observed in nonsymbiotic plants. Endophytes also influenced sexual reproduction of mature big sagebrush (Artemisia tridentata) plants. Two spatially distinct big sagebrush subspecies and their hybrids were symbiotic with unique fungal endophytes, despite being separated by only 380 m distance and 60 m elevation. A double reciprocal transplant experiment of parental and hybrid plants, and soils across the hybrid zone showed that fungal endophytes interact with the soils and different plant genotypes to confer enhanced plant reproduction in soil native to the endophyte and reduced reproduction in soil alien to the endophyte. Moreover, the most prevalent endophyte of the hybrid zone reduced the fitness of both parental subspecies. Because these endophytes are passed to the next generation of plants on seed coats, this interaction provides a selective advantage, habitat specificity, and the means of restricting gene flow, thereby making the hybrid zone stable, narrow and potentially leading to speciation. ?? 2009 Landes Bioscience.

  3. The infrared variability and nature of symbiotic stars. II - RR Tel

    NASA Astrophysics Data System (ADS)

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

    1983-03-01

    The presence of a cool Mira-like component having a period of 387 days is established for the very slow nova symbiotic system RR Tel in the 1972-1981 period, using JHKL IR photometry. Single star models for the system are suggested to be unlikely in view of evidence for a similar periodicity in the photographic region prior to the 1944 outburst. These results are consistent with the presence of a constant period and mean luminosity Mira at all times. If the Mira component is normal, then the IR excess increases toward Mira minimum and may be interpreted as a partial heating of the dust by the blue component and/or ionized gas in the system. The evidence indicates that all slow novae contain cool giant or supergiant components, so that the systems must be of great physical size.

  4. Environmental and Genotypic Effects on the Respiration Associated with Symbiotic Nitrogen Fixation in Peas 1

    PubMed Central

    Mahon, John D.

    1979-01-01

    Estimated values for the respiration associated with symbiotic nitrogen fixation in Pisum sativum L. were independent of irradiance, temperature, plant age, and CO2 concentration, despite large variation in the total rates of C2H2 reduction and root + nodule respiration. Similar values were also found in Phaseolus vulgaris L., Vicia faba L. and Glycine max (L.) Merr. Among all combinations of four Pisum cultivars with four Rhizobium leguminosarum inoculants only the plant genotype significantly affected the fixation-linked respiration, although both plant and bacterial types significantly influenced the total rate of C2H2 reduction. On the basis of measured rates of H2 evolution and C2H2 reduction, or total nitrogen gain in the same system, the least respiration per unit of ammonia produced symbiotically was estimated as 4.8 to 6.9 moles CO2 (mole NH3)−1 in Laxton's Progress and the greatest as 9.3 to 13.3 moles CO2 (mole NH3)−1 in an Indian cultivar, as compared to a theoretical minimum respiration requirement of 4.7 moles CO2 (mole NH3)−1 in peas. PMID:16660833

  5. Symbiotic association between Salix purpurea L. and Rhizophagus irregularis: modulation of plant responses under copper stress.

    PubMed

    Almeida-Rodríguez, Adriana M; Gómes, Marcelo P; Loubert-Hudon, Audrey; Joly, Simon; Labrecque, Michel

    2016-04-01

    There are increasing concerns about trace metal levels such as copper (Cu) in industrial sites and the broader environment. Different studies have highlighted the role of mycorrhizal associations in plant tolerance to trace metals, modulating some of the plant metabolic and physiological responses. In this study, we investigated the role of the symbiotic association betweenRhizophagus irregularisandSalix purpureaL. in modulating plant responses under Cu stress. We measured Cu accumulation, oxidative stress-related, photosynthetic-related and hydraulic traits, for non-inoculated (non-arbuscular mycorrhizal fungi) and inoculated saplings exposed to different Cu concentrations. We found thatS. purpureais a suitable option for phytoremediation of Cu, acting as a phytostabilizer of this trace metal in its root system. We observed that the symbiotic association modulates a broad spectrum of metabolic and physiological responses inS. purpureaunder Cu conditions, including (i) a reduction in gas exchange associated with chlorophyll content changes and (ii) the sequestration of Cu into the cell walls, modifying vessels anatomy and impacting leaf specific conductivity (KL) and root hydraulic conductance (LP). UpholdingKLandLPunder Cu stress might be related to a dynamic Aquaporin gene regulation ofPIP1;2along with an up-regulation ofTIP2;2in the roots of inoculatedS. purpurea. PMID:26546365

  6. A model for the X-ray spectrum of the symbiotic nova RR Telescopii

    NASA Astrophysics Data System (ADS)

    Jordan, S.; Murset, U.; Werner, K.

    1994-03-01

    Pointed ROSAT position sensitive proportional counter (PSPC) observations of the symbiotic nova RR Tel are presented. The PSPC pulse height distribution exhibits a rather soft energy distribution plus few, but significant counts at higher energies. We interprete this as superposition of photospheric flux from the hot component of the symbiotic binary system, and X-rays emitted by a hot plasma, probably shocked by the colliding winds from the two binary components. For modeling the stellar component we use black body emission, as well as line-blanketed non-local thermodynamic equilibrium (NLTE) model atmospheres. Additional constraints for the parameters of the hot star are provided by UV spectra obtained with IUE and VOYAGER. The parameters of the plasma are confined by published EINSTEIN count rates. A stellar atmosphere model with L = 3500 solar luminosity, Teff = 142000 K, log g = 6.5, and solar abundances, complemented with emission of several times 0.01 solar luminosity by a several 106 K hot plasma reproduces both, UV and X-ray data. For the hot star's atmosphere, any other chemical compositions can be excluded.

  7. Specific Hopanoid Classes Differentially Affect Free-Living and Symbiotic States of Bradyrhizobium diazoefficiens

    PubMed Central

    Kulkarni, Gargi; Busset, Nicolas; Molinaro, Antonio; Gargani, Daniel; Chaintreuil, Clemence; Silipo, Alba

    2015-01-01

    ABSTRACT A better understanding of how bacteria resist stresses encountered during the progression of plant-microbe symbioses will advance our ability to stimulate plant growth. Here, we show that the symbiotic system comprising the nitrogen-fixing bacterium Bradyrhizobium diazoefficiens and the legume Aeschynomene afraspera requires hopanoid production for optimal fitness. While methylated (2Me) hopanoids contribute to growth under plant-cell-like microaerobic and acidic conditions in the free-living state, they are dispensable during symbiosis. In contrast, synthesis of extended (C35) hopanoids is required for growth microaerobically and under various stress conditions (high temperature, low pH, high osmolarity, bile salts, oxidative stress, and antimicrobial peptides) in the free-living state and also during symbiosis. These defects might be due to a less rigid membrane resulting from the absence of free or lipidA-bound C35 hopanoids or the accumulation of the C30 hopanoid diploptene. Our results also show that C35 hopanoids are necessary for symbiosis only with the host Aeschynomene afraspera but not with soybean. This difference is likely related to the presence of cysteine-rich antimicrobial peptides in Aeschynomene nodules that induce drastic modification in bacterial morphology and physiology. The study of hopanoid mutants in plant symbionts thus provides an opportunity to gain insight into host-microbe interactions during later stages of symbiotic progression, as well as the microenvironmental conditions for which hopanoids provide a fitness advantage. PMID:26489859

  8. Improving Cardiac Surgical Care: A Work Systems Approach

    PubMed Central

    Wiegmann, Douglas A.; Eggman, Ashley A.; ElBardissi, Andrew W.; Henrickson, Sarah E.; Sundt, Thoralf M.

    2010-01-01

    Over the past 50 years, significant improvements in cardiac surgical care have been achieved. Nevertheless, surgical errors that significantly impact patient safety continue to occur. In order to further improve surgical outcomes, patient safety programs must focus on rectifying work system factors in the operating room (OR) that negatively impact the delivery of reliable surgical care. The goal of this paper is to provide an integrative review of specific work system factors in the OR that may directly impact surgical care processes, as well as the subsequent recommendations that have been put forth to improve surgical outcomes and patient safety. The important role that surgeons can play in facilitating work system changes in the OR is also discussed. The paper concludes with a discussion of the challenges involved in assessing the impact that interventions have on improving surgical care. Opportunities for future research are also highlighted throughout the paper. PMID:20202623

  9. Improving cardiac surgical care: a work systems approach.

    PubMed

    Wiegmann, Douglas A; Eggman, Ashley A; Elbardissi, Andrew W; Parker, Sarah Henrickson; Sundt, Thoralf M

    2010-09-01

    Over the past 50 years, significant improvements in cardiac surgical care have been achieved. Nevertheless, surgical errors that significantly impact patient safety continue to occur. In order to further improve surgical outcomes, patient safety programs must focus on rectifying work system factors in the operating room (OR) that negatively impact the delivery of reliable surgical care. The goal of this paper is to provide an integrative review of specific work system factors in the OR that may directly impact surgical care processes, as well as the subsequent recommendations that have been put forth to improve surgical outcomes and patient safety. The important role that surgeons can play in facilitating work system changes in the OR is also discussed. The paper concludes with a discussion of the challenges involved in assessing the impact that interventions have on improving surgical care. Opportunities for future research are also highlighted throughout the paper. PMID:20202623

  10. A Documentation System for Teacher Improvement or Termination

    ERIC Educational Resources Information Center

    Frels, Kelly; Horton, Janet L.

    2007-01-01

    The primary objective of a school district's teacher evaluation system is to improve teachers' performance so they can become successful and contribute to the objectives of the district. If the evaluation does not produce this positive result, the teacher must be replaced, either by resignation or termination. The district's evaluation system thus…

  11. Are Job Banks Improving The Labor Market Information System?

    ERIC Educational Resources Information Center

    Ullman, Joseph C.; Huber, George P.

    1974-01-01

    Local job banks, computer aided man-job matching systems, are the spearhead of the multiphased Federal program to improve the functioning of the labor market information system. As evaluated here, the program may eventually achieve this objective but the evidence concerning the first phase is not encouraging. (DS)

  12. Method for improving the time resolution of a TOF system

    NASA Astrophysics Data System (ADS)

    Li, Shao-Li; Heng, Yue-Kun; Zhao, Tian-Chi; Fu, Zai-Wei; Liu, Shu-Lin; Qian, Sen; Liu, Shu-Dong; Chen, Xiao-Hui; Jia, Ru; Huang, Guo-Rui; Lei, Xiang-Cui

    2013-01-01

    In order to study the possibility of improving the timing performance of the time of flight (TOF) systems, which are made of plastic scintillator counters, and read out by photomultiplier tubes (PMT) with mesh dynodes and conventional electronics, we have conducted a study using faster PMTs and ultra fast waveform digitizers to read out the plastic scintillators. Different waveform analysis methods are used to calculate the time resolution of such a system. Results are compared with the conventional discriminating method based on a threshold and pulse height. Our tests and analysis show that significant timing performance improvements can be achieved by using this new system.

  13. Application of uniform design to improve dental implant system.

    PubMed

    Cheng, Yung-Chang; Lin, Deng-Huei; Jiang, Cho-Pei

    2015-01-01

    This paper introduces the application of uniform experimental design to improve dental implant systems subjected to dynamic loads. The dynamic micromotion of the Zimmer dental implant system is calculated and illustrated by explicit dynamic finite element analysis. Endogenous and exogenous factors influence the success rate of dental implant systems. Endogenous factors include: bone density, cortical bone thickness and osseointegration. Exogenous factors include: thread pitch, thread depth, diameter of implant neck and body size. A dental implant system with a crest module was selected to simulate micromotion distribution and stress behavior under dynamic loads using conventional and proposed methods. Finally, the design which caused minimum micromotion was chosen as the optimal design model. The micromotion of the improved model is 36.42 μm, with an improvement is 15.34% as compared to the original model. PMID:26406045

  14. Bi-Propellant Propulsion System Improvement for Exported Telecommunication Satellites

    NASA Astrophysics Data System (ADS)

    Garnero, P.; Jamin, A..

    2004-10-01

    The past few years have allowed ALCATEL SPACE to design, develop and qualify complete chemical bi-propellant and electric propulsion systems for use on commercial telecommunication satellites ordered by major satellite operators [1]. Taking into consideration the continuous increase of satellite international competition with respect to price, performances, and adaptation to customer constraints, it was decided to improve the Bi-Propellant Chemical Propulsion System, on the basis of the generic Spacebus 4000 UPS. The improvements are mainly focussed on: -Apogee Boost Motor performance increase for spacecraft mass saving / lifetime increase -Qualification of Attitude Control Thrusters with new thruster valve, for better market flexibility -Pressure Regulation Module and Propellant Regulation Module qualified at system level with use of new components from European suppliers, for better market flexibility linked to exportation contraints. The aim of this paper is to describe the development and qualification status of this improved Propulsion System.

  15. [Wawared Peru: reducing health inequities and improving maternal health by improving information systems in health].

    PubMed

    Pérez-Lu, José E; Iguiñiz Romero, Ruth; Bayer, Angela M; García, Patricia J

    2015-01-01

    In developing countries, there are no high quality data to support decision-making and governance due to inadequate information collection and transmission processes. Our project WawaRed-Peru: "Reducing health inequities and improving maternal health by improving health information systems" aims to improve maternal health processes and indicators through the implementation of interoperability standards for maternal health information systems in order for decision makers to have timely, high quality information. Through this project, we hope to support the development of better health policies and to also contribute to reducing problems of health equity among Peruvian women and potentially women in other developing countries. The aim of this article is to present the current state of information systems for maternal health in Peru. PMID:26338401

  16. Improving health care systems performance: a human factors approach.

    PubMed

    Silver, Michael P; Geis, Michelle S; Bateman, Kim A

    2004-01-01

    Under contract from the Centers for Medicare & Medicaid Services (CMS), Medicare Quality Improvement Organizations (QIOs) promote improvement in health care system performance. With the QIO contract cycle that began in the fall of 1999, CMS adopted a broad national improvement agenda emphasizing 24 quality measures from 6 clinical topic areas. The Utah QIO developed a human factors and organizational safety management-based intervention strategy for the inpatient clinical topic areas, borrowing approaches and principles previously applied in hospital-based medication systems safety improvement efforts. Evaluation used measures and methods established by CMS to assess the adequacy of QIO performance nationwide. Comparison of statewide inpatient quality indicator performance rates in 1998 and 2000 showed absolute improvement on 15 of the 16 measures used. The average reduction in the failure rate for these clinical topic areas in Utah was 27.3%; this was the highest rate of improvement for any state in the nation. Utah's overall ranking on the combined inpatient clinical topic areas went from 16th at baseline to first at follow-up. The evaluation demonstrates exceptional levels of performance improvement in Utah hospitals when compared with national trends. It is, however, neither possible to uniquely isolate the effects of the QIO intervention from larger trends operating statewide, nor can the contributions of the various facets of the QIO intervention be disaggregated. The application of human factors and organizational safety management principles represents a promising strategy for accelerating the pace of improvement in health care. PMID:15212314

  17. A System That Works: Highlights of Effective Intervention Strategies in a Quality Improvement System

    ERIC Educational Resources Information Center

    Sinisterra, Diana; Baker, Stephen

    2010-01-01

    This paper describes one approach to quality improvement efforts: the Quality Improvement System (QIS) implemented by Prime Time Palm Beach County (Prime Time) in Palm Beach County, Florida. Prime Time's QIS is recognized as one promising systemic effort to improve quality in the afterschool field (Yohalem, Granger, & Pittman, 2009). As a…

  18. Design of launch systems using continuous improvement process

    NASA Technical Reports Server (NTRS)

    Brown, Richard W.

    1995-01-01

    The purpose of this paper is to identify a systematic process for improving ground operations for future launch systems. This approach is based on the Total Quality Management (TQM) continuous improvement process. While the continuous improvement process is normally identified with making incremental changes to an existing system, it can be used on new systems if they use past experience as a knowledge base. In the case of the Reusable Launch Vehicle (RLV), the Space Shuttle operations provide many lessons. The TQM methodology used for this paper will be borrowed from the United States Air Force 'Quality Air Force' Program. There is a general overview of the continuous improvement process, with concentration on the formulation phase. During this phase critical analyses are conducted to determine the strategy and goals for the remaining development process. These analyses include analyzing the mission from the customers point of view, developing an operations concept for the future, assessing current capabilities and determining the gap to be closed between current capabilities and future needs and requirements. A brief analyses of the RLV, relative to the Space Shuttle, will be used to illustrate the concept. Using the continuous improvement design concept has many advantages. These include a customer oriented process which will develop a more marketable product and a better integration of operations and systems during the design phase. But, the use of TQM techniques will require changes, including more discipline in the design process and more emphasis on data gathering for operational systems. The benefits will far outweigh the additional effort.

  19. Weyerhaeuser: Compressed Air System Improvement Saves Energy and Improves Production at a Sawmill

    SciTech Connect

    2004-11-01

    In 2000, Weyerhaeuser Company, a U.S. Department of Energy Allied Partner in the Industrial Technologies Program, increased the efficiency of the compressed air system at its sawmill facility in Coburg, Oregon. This improved the system's performance and will save about 1.3 million kWh annually. Total project costs were $55,000; because annual energy cost savings were also $55,000, the simple payback period was only 1 year. Subsequent improvements at six other company plants and mills are yielding 6.8 million kWh in energy savings and reducing annual energy costs by $250,000.

  20. Symbiotic intelligence: Self-organizing knowledge on distributed networks, driven by human interaction

    SciTech Connect

    Johnson, N.; Joslyn, C.; Rocha, L.; Smith, S.; Kantor, M.; Rasmussen, S. |

    1998-07-01

    This work addresses how human societies, and other diverse and distributed systems, solve collective challenges that are not approachable from the level of the individual, and how the Internet will change the way societies and organizations view problem solving. The authors apply the ideas developed in self-organizing systems to understand self-organization in informational systems. The simplest explanation as to why animals (for example, ants, wolves, and humans) are organized into societies is that these societies enhance the survival of the individuals which make up the populations. Individuals contribute to, as well as adapt to, these societies because they make life easier in one way or another, even though they may not always understand the process, either individually or collectively. Despite the lack of understanding of the how of the process, society during its existence as a species has changed significantly, from separate, small hunting tribes to a highly technological, globally integrated society. The authors combine this understanding of societal dynamics with self-organization on the Internet (the Net). The unique capability of the Net is that it combines, in a common medium, the entire human-technological system in both breadth and depth: breadth in the integration of heterogeneous systems of machines, information and people; and depth in the detailed capturing of the entire complexity of human use and creation of information. When the full diversity of societal dynamics is combined with the accuracy of communication on the Net, a phase transition is argued to occur in problem solving capability. Through conceptual examples, an experiment of collective decision making on the Net and a simulation showing the effect of noise and loss on collective decision making, the authors argue that the resulting symbiotic structure of humans and the Net will evolve as an alternative problem solving approach for groups, organizations and society. Self

  1. Spontaneous improvement of laryngeal sarcoidosis resistant to systemic corticosteroid administration

    PubMed Central

    Tsubouchi, Kazuya; Hamada, Naoki; Ijichi, Kayo; Umezaki, Toshiro; Takayama, Koichi; Nakanishi, Yoichi

    2015-01-01

    We report herein a case of laryngeal sarcoidosis that was refractory to systemic corticosteroids, but that improved spontaneously. A 49-year-old woman complained of dysphagia and hoarseness with accompanying edematous swellings of both arytenoid regions. She was referred to our hospital after systemic corticosteroid therapy failed to achieve any improvement. Laryngoscopy showed marked edema of the epiglottis and both arytenoid regions. The flow–volume curve on spirometry showed flattening of the expiratory flows. Histopathological examination of the arytenoid region showed non-caseating epithelioid granulomas, and laryngeal sarcoidosis was diagnosed with the result of BAL study. She was observed without treatment as symptoms were mild. Although edema of the left arytenoid region seemed to be somewhat worsened after 6 months, she continued to be followed closely because of improvements in the flow–volume curve and increasing peak expiratory flow. By 1 year after onset, symptoms and epiglottal swelling had spontaneously improved. PMID:26392860

  2. Do symbiotic microbes have a role in plant evolution, performance and response to stress?

    PubMed Central

    Lucero, Mary E; Reyes-Vera, Isaac; Havstad, Kris M

    2008-01-01

    Vascular plants have been considered as autonomous organisms especially when their performance has been interpreted at the genome and cellular level. In reality, vascular plants provide a unique ecological niche for diverse communities of cryptic symbiotic microbes which often contribute multiple benefits, such as enhanced photosynthetic efficiency, nutrient and water use and tolerance to abiotic and biotic stress. These benefits are similar to improvements sought by plant scientists working to develop ecologically sustainable crops for food, fiber and biofuels. Native desert plants include a community of indigenous endosymbiotic fungi that are structural components with cells, tissues, cell cultures and regenerated plants. These fungi regulate plant growth and development and contribute genes and natural products that enable plants to adapt to changing environments. A method developed for transferring these endophytes from cell cultures to non-host plants promises to be a revolutionary approach for the development of novel plant germplasm and has application in the field of plant biotechnology. PMID:19513202

  3. INTEGRATED SAFETY MANAGEMENT SYSTEM SAFETY CULTURE IMPROVEMENT INITIATIVE

    SciTech Connect

    MCDONALD JA JR

    2009-01-16

    In 2007, the Department of Energy (DOE) identified safety culture as one of their top Integrated Safety Management System (ISMS) related priorities. A team was formed to address this issue. The team identified a consensus set of safety culture principles, along with implementation practices that could be used by DOE, NNSA, and their contractors. Documented improvement tools were identified and communicated to contractors participating in a year long pilot project. After a year, lessons learned will be collected and a path forward determined. The goal of this effort was to achieve improved safety and mission performance through ISMS continuous improvement. The focus of ISMS improvement was safety culture improvement building on operating experience from similar industries such as the domestic and international commercial nuclear and chemical industry.

  4. Shuttle waste management system design improvements and flight evaluation

    NASA Technical Reports Server (NTRS)

    Winkler, H. Eugene; Goodman, Jerry R.; Murray, Robert W.; Mcintosh, Mathew E.

    1986-01-01

    The Space Shuttle waste management system has undergone a variety of design changes to improve performance and man-machine interface. These design improvements have resulted in more reliable operation and hygienic usage. Design enhancements include individual urinals, increased urine collection airflows, increased solids storage capacity, easier access to personal hygiene items, and additional wet trash stowage. The development and flight evaluation of these improvements are described herein. The Space Shuttle Orbiter has proved to be an invaluable test bed for development and in-flight evaluation of life support and habitability concepts which involve transport or separation of solids, liquids, and gases in a zero-g environment.

  5. Identification of components to optimize improvement in system reliability

    SciTech Connect

    Painton, L.; Campbell, J.

    1993-10-01

    The fields of reliability analysis and risk assessment have grown dramatically since the 1970s. There are now bodies of literature and standard practices which cover quantitative aspects of system analysis such as failure rate and repair models, fault and event tree generation, minimal cut sets, classical and Bayesian analysis of reliability, component and system testing techniques, decomposition methods, etc. In spite of the growth in the sophistication of reliability models, however, little has been done to integrate optimization models within a reliability analysis framework. That is, often reliability models focus on characterization of system structure in terms of topology and failure/availability characteristics of components. A number of approaches have been proposed to help identify the components of a system that have the largest influence on overall system reliability. While this may help rank order the components, it does not necessarily help a system design team identify which components they should improve to optimize overall reliability (it may be cheaper and more effective to focus on improving two or three components of smaller importance than one component of larger importance). In this paper, we present an optimization model that identifies the components to be improved to maximize the increase in system MTBF, subject to a fixed budget constraint. A dual formulation of the model is to minimize cost, subject to achieving a certain level of system reliability.

  6. Overview on gastroretentive drug delivery systems for improving drug bioavailability.

    PubMed

    Lopes, Carla M; Bettencourt, Catarina; Rossi, Alessandra; Buttini, Francesca; Barata, Pedro

    2016-08-20

    In recent decades, many efforts have been made in order to improve drug bioavailability after oral administration. Gastroretentive drug delivery systems are a good example; they emerged to enhance the bioavailability and effectiveness of drugs with a narrow absorption window in the upper gastrointestinal tract and/or to promote local activity in the stomach and duodenum. Several strategies are used to increase the gastric residence time, namely bioadhesive or mucoadhesive systems, expandable systems, high-density systems, floating systems, superporous hydrogels and magnetic systems. The present review highlights some of the drugs that can benefit from gastroretentive strategies, such as the factors that influence gastric retention time and the mechanism of action of gastroretentive systems, as well as their classification into single and multiple unit systems. PMID:27173823

  7. Dual involvement of a Medicago truncatula NAC transcription factor in root abiotic stress response and symbiotic nodule senescence.

    PubMed

    de Zélicourt, Axel; Diet, Anouck; Marion, Jessica; Laffont, Carole; Ariel, Federico; Moison, Michaël; Zahaf, Ons; Crespi, Martin; Gruber, Véronique; Frugier, Florian

    2012-04-01

    Legume crops related to the model plant Medicago truncatula can adapt their root architecture to environmental conditions, both by branching and by establishing a symbiosis with rhizobial bacteria to form nitrogen-fixing nodules. Soil salinity is a major abiotic stress affecting plant yield and root growth. Previous transcriptomic analyses identified several transcription factors linked to the M. truncatula response to salt stress in roots, including NAC (NAM/ATAF/CUC)-encoding genes. Over-expression of one of these transcription factors, MtNAC969, induced formation of a shorter and less-branched root system, whereas RNAi-mediated MtNAC969 inactivation promoted lateral root formation. The altered root system of over-expressing plants was able to maintain its growth under high salinity, and roots in which MtNAC969 was down-regulated showed improved growth under salt stress. Accordingly, expression of salt stress markers was decreased or induced in MtNAC969 over-expressing or RNAi roots, respectively, suggesting a repressive function for this transcription factor in the salt-stress response. Expression of MtNAC969 in central symbiotic nodule tissues was induced by nitrate treatment, and antagonistically affected by salt in roots and nodules, similarly to senescence markers. MtNAC969 RNAi nodules accumulated amyloplasts in the nitrogen-fixing zone, and were prematurely senescent. Therefore, the MtNAC969 transcription factor, which is differentially affected by environmental cues in root and nodules, participates in several pathways controlling adaptation of the M. truncatula root system to the environment. PMID:22098255

  8. Drought enhances symbiotic dinitrogen fixation and competitive ability of a temperate forest tree.

    PubMed

    Wurzburger, Nina; Miniat, Chelcy Ford

    2014-04-01

    General circulation models project more intense and frequent droughts over the next century, but many questions remain about how terrestrial ecosystems will respond. Of particular importance, is to understand how drought will alter the species composition of regenerating temperate forests wherein symbiotic dinitrogen (N2)-fixing plants play a critical role. In experimental mesocosms we manipulated soil moisture to study the effect of drought on the physiology, growth and competitive interactions of four co-occurring North American tree species, one of which (Robinia pseudoacacia) is a symbiotic N2-fixer. We hypothesized that drought would reduce growth by decreasing stomatal conductance, hydraulic conductance and increasing the water use efficiency of species with larger diameter xylem vessel elements (Quercus rubra, R. pseudoacacia) relative to those with smaller elements (Acer rubrum and Liriodendron tulipifera). We further hypothesized that N2 fixation by R. pseudoacacia would decline with drought, reducing its competitive ability. Under drought, growth declined across all species; but, growth and physiological responses did not correspond to species' hydraulic architecture. Drought triggered an 80% increase in nodule biomass and N accrual for R. pseudoacacia, improving its growth relative to other species. These results suggest that drought intensified soil N deficiency and that R. pseudoacacia's ability to fix N2 facilitated competition with non-fixing species when both water and N were limiting. Under scenarios of moderate drought, N2 fixation may alleviate the N constraints resulting from low soil moisture and improve competitive ability of N2-fixing species, and as a result, supply more new N to the ecosystem. PMID:24337710

  9. Development of the improved helicopter icing spray system (IHISS)

    NASA Technical Reports Server (NTRS)

    Peterson, Andrew A.; Jenks, Mark D.; Gaitskill, William H.

    1989-01-01

    Boeing Helicopters has been awarded a contract by the U.S. Army to design, fabricate and test a replacement for the existing Helicopter Icing Spray System (HISS). The Improved Hiss (IHISS), capable of deployment from any CH-47D helicopter, will include new icing spray nozzles and pneumatic pressure source, and a significantly larger water tank and spray boom. Results are presented for extensive bench and icing tunnel test programs used to select and modify an improved spray nozzle and validate spray boom aerodynamic characteristics. The resulting system will provide a significantly larger icing cloud with droplet characteristics closely matching natural icing conditions.

  10. Improved colorization for night vision system based on image splitting

    NASA Astrophysics Data System (ADS)

    Ali, E.; Kozaitis, S. P.

    2015-03-01

    The success of a color night navigation system often depends on the accuracy of the colors in the resulting image. Often, small regions can incorrectly adopt the color of large regions simply due to size of the regions. We presented a method to improve the color accuracy of a night navigation system by initially splitting a fused image into two distinct sections before colorization. We split a fused image into two sections, generally road and sky regions, before colorization and processed them separately to obtain improved color accuracy of each region. Using this approach, small regions were colored correctly when compared to not separating regions.

  11. Software and hardware improvements for digital solar magnetograph system

    NASA Astrophysics Data System (ADS)

    Yang, Shu

    Digital solar imaging systems have been widely used in solar observations. Their high resolution, high rate of image acquisition and convenience for off-line image processing have provided significant improvements to solar physics research. In this project, two digital magnetograph systems established at Big Bear Solar Observatory (BBSO) have been described. One is used to provide a high frame rate magnetogram system, and the other provides a real-time image alignment, i.e., a correlation tracker system. The developed correlation tracker system consists of a high-speed 64 x 64 CCD camera, an EDT image grabbing board, an agile mirror, a D/A board and a Sun Ultra-30 workstation. Based on the same hardware, digital magnetograph system has been built and tested. The novel correlation tracker system does not use traditional FFT hardware and is more integrated in a Sun Ultra-30. The system software has been developed by using C and Motif graphical user interface under Solaris 2.6. Both systems have been demonstrated to work very efficiently at BBSO. After tens of thousands of solar magnetograms have been grabbed with the digital magnetograph system, various image processing methods have been studied to improve resolution, eliminate image noise and stray light effect. The efficiencies of different processing methods have been discussed and their Fourier spectra have been analyzed. After noise deduction and stray light elimination, the processed magnetograms have been proved to be much better than the original images.

  12. Transcriptome analyses to investigate symbiotic relationships between marine protists

    PubMed Central

    Balzano, Sergio; Corre, Erwan; Decelle, Johan; Sierra, Roberto; Wincker, Patrick; Da Silva, Corinne; Poulain, Julie; Pawlowski, Jan; Not, Fabrice

    2015-01-01

    Rhizaria are an important component of oceanic plankton communities worldwide. A number of species harbor eukaryotic microalgal symbionts, which are horizontally acquired in the environment at each generation. Although these photosymbioses are determinant for Rhizaria ability to thrive in oceanic ecosystems, the mechanisms for symbiotic interactions are unclear. Using high-throughput sequencing technology (i.e., 454), we generated large Expressed Sequence Tag (EST) datasets from four uncultured Rhizaria, an acantharian (Amphilonche elongata), two polycystines (Collozoum sp. and Spongosphaera streptacantha), and one phaeodarian (Aulacantha scolymantha). We assessed the main genetic features of the host/symbionts consortium (i.e., the holobiont) transcriptomes and found rRNA sequences affiliated to a wide range of bacteria and protists in all samples, suggesting that diverse microbial communities are associated with the holobionts. A particular focus was then carried out to search for genes potentially involved in symbiotic processes such as the presence of c-type lectins-coding genes, which are proteins that play a role in cell recognition among eukaryotes. Unigenes coding putative c-type lectin domains (CTLD) were found in the species bearing photosynthetic symbionts (A. elongata, Collozoum sp., and S. streptacantha) but not in the non-symbiotic one (A. scolymantha). More particularly, phylogenetic analyses group CTLDs from A. elongata and Collozoum sp. on a distinct branch from S. streptacantha CTLDs, which contained carbohydrate-binding motifs typically observed in other marine photosymbiosis. Our data suggest that similarly to other well-known marine photosymbiosis involving metazoans, the interactions of glycans with c-type lectins is likely involved in modulation of the host/symbiont specific recognition in Radiolaria. PMID:25852650

  13. BTS Fact Sheet: Improving the efficiency of your duct system

    SciTech Connect

    BNL

    1999-12-28

    The duct system, used in air heating and air cooling your home, is a collection of tubes that distributes the heated or cooled air to the various rooms. The duct system can have an important effect on health of the occupants through the distribution of indoor air pollution. Changes and repairs to a duct system should always be performed by a qualified professional. This brochure is meant to help you understand the problems that can affect the duct system and how you can save money, improve comfort, and protect against potential health hazards.

  14. COMPARING SYMBIOTIC NEBULAE AND PLANETARY NEBULAE LUMINOSITY FUNCTIONS

    SciTech Connect

    Frankowski, Adam; Soker, Noam E-mail: soker@physics.technion.ac.i

    2009-10-01

    We compare the observed symbiotic nebulae (SyN) luminosity function (SyNLF) in the [O III] lambda5007 A line to the planetary nebulae (PN) luminosity function (PNLF) and find that the intrinsic SyNLF (ISyNLF) of galactic SyNs has-within its uncertainty of 0.5-0.8 mag-very similar cutoff luminosity and general shape to those of the PNLF. The [O III]/(Halpha+[N II]) line ratios of SyNs and PNs are shown to be also related. Possible implications of these results for the universality of the PNLF are briefly outlined.

  15. Light and the bioenergetics of a symbiotic coral

    SciTech Connect

    Falkowski, P.G.; Dubinsky, Z.; Muscatine, L.; Porter, J.W.

    1984-12-01

    Colonies of coral Stylophora pistillata growing at high light can obtain all the reduced carbon needed for animal respiration from photosynthesis by symbiotic zooxanthellae. In contrast, colonies in shaded reef areas must acquired 60% of their reduced carbon heterotrophically. More than 90% of the carbon fixed by zooxanthellae is translocated to the animal host in both light regimes, but very little is assimilated, apparently because the translocated products are deficient in nitrogen. Thus, the coral's overall growth efficiency is similar to that of aquatic herbivores that forage actively. 29 references, 2 figures, 1 table.

  16. Process approach in developing or improvement of student information systems

    NASA Astrophysics Data System (ADS)

    Jaskowska, Małgorzata

    2015-02-01

    An aim of research described in the article was to evaluate usefulness of the university information system, which precedes its reorganization. The study was conducted among representatives of all stakeholders - system users: candidates, students and university authorities. A need of system users expressed in the study: change of the approach in its construction - from purely information to procedural, it is consistent with a current process approach in systems design, intensified by the fashionable service oriented architecture (SOA). This thread was developed by conducting literature research and analysis of student information systems best practices. As a result the processes were selected and described, which implementation may assist the university system. Research result can be used by system designers for its improvement.

  17. Improving Childhood Obesity Treatment Using New Technologies: The ETIOBE System.

    PubMed

    Baños, Rosa M; Cebolla, Ausias; Botella, Cristina; García-Palacios, Azucena; Oliver, Elia; Zaragoza, Irene; Alcaniz, Mariano

    2011-01-01

    Childhood obesity is an increasing public health problem in western culture. Sedentary lifestyles and an "obesogenic environment" are the main influences on children leading to an increase in obesity. The objective of this paper is to describe an e-health platform for the treatment and prevention of childhood obesity called ETIOBE. This e-health platform is an e-therapy system for the treatment of obesity, aimed at improving treatment adherence and promoting the mechanisms of self-control in patients, to obtain weight loss maintenance and to prevent relapse by establishing healthy lifestyle habits. ETIOBE is composed of three different applications, the Clinician Support System (CSS), the Home Support System (HSS) and the Mobile Support System (MSS). The use of new Information and Communication (ICT) technologies can help clinicians to improve the effectiveness of weight loss treatments, especially in the case of children, and to achieve designated treatment goals. PMID:21559232

  18. Improving Childhood Obesity Treatment Using New Technologies: The ETIOBE System

    PubMed Central

    Baños, Rosa. M; Cebolla, Ausias; Botella, Cristina; García-Palacios, Azucena; Oliver, Elia; Zaragoza, Irene; Alcaniz, Mariano

    2011-01-01

    Childhood obesity is an increasing public health problem in western culture. Sedentary lifestyles and an “obesogenic environment” are the main influences on children leading to an increase in obesity. The objective of this paper is to describe an e-health platform for the treatment and prevention of childhood obesity called ETIOBE. This e-health platform is an e-therapy system for the treatment of obesity, aimed at improving treatment adherence and promoting the mechanisms of self-control in patients, to obtain weight loss maintenance and to prevent relapse by establishing healthy lifestyle habits. ETIOBE is composed of three different applications, the Clinician Support System (CSS), the Home Support System (HSS) and the Mobile Support System (MSS). The use of new Information and Communication (ICT) technologies can help clinicians to improve the effectiveness of weight loss treatments, especially in the case of children, and to achieve designated treatment goals. PMID:21559232

  19. Symbiotic physiology promotes homeostasis in Daisyworld.

    PubMed

    Boyle, Richard A; Lenton, Timothy M; Watson, Andrew J

    2011-04-01

    colonises and to an extent makes habitable an otherwise lifeless environment, but is later displaced by free-living genotypes that have higher local fitness once conditions improve. The final result is arguably analogous to lichen colonisation of the Neoproterozoic land surface, followed by the Phanerozoic rise of vascular plants. Caution is necessary in extrapolating from the Daisyworld parable to real ecology/geochemistry, but sufficiently conserved variables may be water potential, macronutrient stoichiometry and (to a lesser extent) the temperature window for metabolic activity. PMID:21236264

  20. An Approach to Bilateral Control System for Improvement of Operationality

    NASA Astrophysics Data System (ADS)

    Tanaka, Hiroyuki; Ohnishi, Kouhei

    Many types of bilateral control architectures to transmit force sensation have been proposed. Some control methods obtain good performance. Operationality is not satisfactory, however, when these methods are implemented in bilateral systems with large inertia and friction force. In this paper, a novel bilateral control method is proposed to improve operationality of bilateral systems with large inertia and friction force. The proposed method is compared with a conventional method, and the effectiveness of the proposed method is demonstrated by coordinate transformation and experiments.

  1. Effect of Subliminal Stimulation of Symbiotic Fantasies on College Student Self-Disclosure in Group Counseling.

    ERIC Educational Resources Information Center

    Linehan, Edward; O'Toole, James

    1982-01-01

    Studied subliminal symbiotic stimulation as a treatment aid in conjunction with counselor self-disclosures in group counseling. Results showed that subliminal exposure to MOMMY AND I ARE ONE stimulus would lead to more client self-disclosures in group counseling. Suggests impact of symbiotic stimulus can be affected by counselor behavior. (RC)

  2. Gene Expression in Gut Symbiotic Organ of Stinkbug Affected by Extracellular Bacterial Symbiont

    PubMed Central

    Futahashi, Ryo; Tanaka, Kohjiro; Tanahashi, Masahiko; Nikoh, Naruo; Kikuchi, Yoshitomo; Lee, Bok Luel; Fukatsu, Takema

    2013-01-01

    The bean bug Riptortus pedestris possesses a specialized symbiotic organ in a posterior region of the midgut, where numerous crypts harbor extracellular betaproteobacterial symbionts of the genus Burkholderia. Second instar nymphs orally acquire the symbiont from the environment, and the symbiont infection benefits the host by facilitating growth and by occasionally conferring insecticide resistance. Here we performed comparative transcriptomic analyses of insect genes expressed in symbiotic and non-symbiotic regions of the midgut dissected from Burkholderia-infected and uninfected R. pedestris. Expression sequence tag analysis of cDNA libraries and quantitative reverse transcription PCR identified a number of insect genes expressed in symbiosis- or aposymbiosis-associated patterns. For example, genes up-regulated in symbiotic relative to aposymbiotic individuals, including many cysteine-rich secreted protein genes and many cathepsin protease genes, are likely to play a role in regulating the symbiosis. Conversely, genes up-regulated in aposymbiotic relative to symbiotic individuals, including a chicken-type lysozyme gene and a defensin-like protein gene, are possibly involved in regulation of non-symbiotic bacterial infections. Our study presents the first transcriptomic data on gut symbiotic organ of a stinkbug, which provides initial clues to understanding of molecular mechanisms underlying the insect-bacterium gut symbiosis and sheds light on several intriguing commonalities between endocellular and extracellular symbiotic associations. PMID:23691247

  3. Implementing Improved Security and Encryption for Balloon Flight Systems

    NASA Astrophysics Data System (ADS)

    Denney, Andrew; Stilwell, Bryan D.

    The Columbia Scientific Balloon Facility uses a broad array of communication techniques be-tween its balloon-borne flight systems and ground command and control systems. These com-munication mediums vary from commercially available routing such as e-mail and IP based TCP/UDP protocols to military grade proprietary line-of-sight configurations; each with their own unique benefits and shortfalls. While each new advancement in technology improves secu-rity in some capacity, it does not always address the limitation of older, less advanced security or encryption capabilities. As the proliferation of newer, more commercially viable technologies become common place, safeguarding mission critical applications from unauthorized access and improve data integrity in the process becomes ever more necessary. Therefore, this paper will evaluate several security measures and methods of data encryption; including formalizing a standardized security philosophy that improves and addresses the mixture of established and emerging technologies.

  4. Improving building energy system performance by continuous commissioning

    SciTech Connect

    Liu, M.

    1999-10-01

    Commissioning has played an important role in improved building comfort and reduced energy consumption. This article presents an advanced form of commissioning for existing buildings, called continuous commissioning (CC), which has produced energy savings comparable to those produced by the traditional audit/retrofit process at a third of the cost. It has also increased operating staff skills, reduced maintenance costs, and improved building comfort--extras which are not provided by usual retrofit programs. This article will present the philosophy, process, cost, and savings. Continuous commissioning is a process developed by the Energy Systems Laboratory (ESL) to: (1) optimize the operation of existing systems to improve building comfort and reduce building energy cost; (2) solve existing comfort and IAQ problems; (3) guarantee continuous optimal operation by operational staff in future years; and (4) provide optimal energy retrofit suggestions to owners to minimize the project costs.

  5. Leading Systemic Improvement: Confronting Complexity in Turnaround Schools

    ERIC Educational Resources Information Center

    Peurach, Donald J.; Marx, Gary E.

    2010-01-01

    This case is developed for use in a policy-centered course on systemic improvement in underperforming districts and schools. The narrative details the complexity that arose in the context of one such reform initiative, a framework for analyzing that complexity, and a set of leadership decisions that follow. Course instructors can use the case to:…

  6. Quality Rating and Improvement Systems and Children's Cognitive Development

    ERIC Educational Resources Information Center

    Jeon, Lieny; Buettner, Cynthia K.

    2015-01-01

    Background: Providing enriched learning environments is important to stimulating children's development in early childhood. Early child-care policymakers in many states in the US have adopted Quality Rating and Improvement Systems (QRIS) as a way to verify quality of child care and to support children's school readiness. Objective: The purpose of…

  7. Needed improvements in the development of systemic corrective actions.

    SciTech Connect

    Campisi, John A.

    2009-07-01

    There are indications that corrective actions, as implemented at Sandia National Laboratories are not fully adequate. Review of independent audits spanning multiple years provides evidence of recurring issues within the same or similar operations and programs. Several external audits have directly called into question the ability Sandia's assessment and evaluation processes to prevent recurrence. Examples of repeated findings include lockout/tagout programs, local exhaust ventilation controls and radiological controls. Recurrence clearly shows that there are underlying systemic factors that are not being adequately addressed by corrective actions stemming from causal analyses. Information suggests that improvements in the conduct of causal analyses and, more importantly, in the development of subsequent corrective actions are warranted. Current methodolgies include Management Oversight Risk Tree, developed in the early 1970s and Systemic Factors Analysis. Recommendations for improvements include review of other causal analysis systems, training, improved formality of operations, improved documentation, and a corporate method that uses truly systemic solutions. This report was written some years ago and is being published now to form the foundation for current, follow-on reports being developed. Some outdated material is recognized but is retained for report completeness.

  8. Effects of Quality Improvement System for Child Care Centers

    ERIC Educational Resources Information Center

    Ma, Xin; Shen, Jianping; Kavanaugh, Amy; Lu, Xuejin; Brandi, Karen; Goodman, Jeff; Till, Lance; Watson, Grace

    2011-01-01

    Using multiple years of data collected from about 100 child care centers in Palm Beach County, Florida, the authors studied whether the Quality Improvement System (QIS) made a significant impact on quality of child care centers. Based on a pre- and postresearch design spanning a period of 13 months, QIS appeared to be effective in improving…

  9. Adjusting the detection window to improve the soliton communication system

    NASA Astrophysics Data System (ADS)

    Chi, Sien; Kao, Chuan-Yuan; Dung, Jeng-Cherng; Wen, Senfar

    2000-12-01

    The improvements of the Q factors of 10-Gb/s soliton systems detected by adjusting detection window are studied. We have found that the optimal width of the detection window depends on the noise-induced timing jitter, noise-induced soliton energy fluctuation, amplifier noise, dispersive wave, and soliton pulse width.

  10. Improving Handover Quality in 4G Mobile Systems

    NASA Astrophysics Data System (ADS)

    Kim, Dongwook; Lee, Hanjin; Kim, Namgi; Yoon, Hyunsoo

    In this paper, we propose a new handover algorithm to guarantee handover quality in 4G mobile systems. The proposed algorithm limits the handover interruption time by improving the HARQ retransmission latency of the first packet transmitted from new serving cell. Through the simulations, we proved that our algorithm meets the requirement of handover interruption time for TCP services with high rate.

  11. A Peer Assessment System to Improve Student Team Experiences

    ERIC Educational Resources Information Center

    Anson, Robert; Goodman, James A.

    2014-01-01

    Groups are frequently used in courses, but there is substantial evidence that insufficient attention is paid to creating conditions for successful teamwork. One key condition is high-quality, individual, and team-level feedback. An online peer assessment system and team improvement process was developed for this test case based on three design…

  12. Continuous Improvement in California Education: Data Systems and Policy Learning

    ERIC Educational Resources Information Center

    Loeb, Susanna; Plank, David N.

    2007-01-01

    The "Getting Down to Facts" (GDTF) studies released in March 2007 offered a clear diagnosis of the issues facing California's education system. Now, as California moves beyond the facts and begins the search for ways to improve the performance of California schools and students, the state faces a critical policy dilemma. On the one hand, the…

  13. Effect of cadmium on symbiotic soybean plants

    SciTech Connect

    Borges, A.C.; Wollum, A.G. II

    1981-04-01

    The potential for environmental contamination by cadmium (Cd) has increased significantly in recent years. Since Cd may be hazardous to living systems, a study was conducted to investigate: (1) the existence of Rhizobium japonicum strains tolerant to Cd, (2) the Cd effect on the symbiosis between host soybean plants (Glycine max (L.) Merr.) and R. japonicum strains with different Cd tolerances, and (3) interactions and distribution of Cd and other elements in the host when biomass is decreased by Cd. The existence of R. japonicum strains tolerant to Cd was assessed by comparing growth curves of 10 different strains growing in a basal medium with gluconate, yeast extract, L-arabinose, and Cd (0, 3.5, 7, 14, and 28 ..mu..g/ml). Strain 3Ilb110 (110) exhibited a tolerance to Cd after an initial lag in growth, while strain 3Ilb123 (123) was susceptible. Strains 110 and 123 were used to inoculate plants growing in nutrient solution with Perlite as a support medium to evaluate the plant-rhizobial interactions in the presence of 0, 2.2, 6.7, 10.1, and 20.2 ..mu..g Cd/ml, respectively. Plants were harvested and tops, roots, and nodules were analyzed 23 days after starting Cd application. Cadmium decreased dry matter production of tops, roots, and nodules. Plants inoculated with strain 123 accumulated significantly more dry matter in nodules than those with strain 110. However, in the presence of 0 and 2.2 ..mu..g Cd/ml, plants innoculated with strain 110 accumulated significantly more N than plants innoculated with strain 123. Nutrient imbalances were observed in the presence of Cd. It is suggested that the interactions of Cd with some nutrients may contribute to Cd toxicity in soybean plants. In this study the most pronounced Cd effect was on Fe and Mn nutrition, rather than Zn as had been previously reported.

  14. A single evolutionary innovation drives the deep evolution of symbiotic N2-fixation in angiosperms

    PubMed Central

    Werner, Gijsbert D. A.; Cornwell, William K.; Sprent, Janet I.; Kattge, Jens; Kiers, E. Toby

    2014-01-01

    Symbiotic associations occur in every habitat on earth, but we know very little about their evolutionary histories. Current models of trait evolution cannot adequately reconstruct the deep history of symbiotic innovation, because they assume homogenous evolutionary processes across millions of years. Here we use a recently developed, heterogeneous and quantitative phylogenetic framework to study the origin of the symbiosis between angiosperms and nitrogen-fixing (N2) bacterial symbionts housed in nodules. We compile the largest database of global nodulating plant species and reconstruct the symbiosis’ evolution. We identify a single, cryptic evolutionary innovation driving symbiotic N2-fixation evolution, followed by multiple gains and losses of the symbiosis, and the subsequent emergence of ‘stable fixers’ (clades extremely unlikely to lose the symbiosis). Originating over 100 MYA, this innovation suggests deep homology in symbiotic N2-fixation. Identifying cryptic innovations on the tree of life is key to understanding the evolution of complex traits, including symbiotic partnerships. PMID:24912610

  15. A single evolutionary innovation drives the deep evolution of symbiotic N2-fixation in angiosperms.

    PubMed

    Werner, Gijsbert D A; Cornwell, William K; Sprent, Janet I; Kattge, Jens; Kiers, E Toby

    2014-01-01

    Symbiotic associations occur in every habitat on earth, but we know very little about their evolutionary histories. Current models of trait evolution cannot adequately reconstruct the deep history of symbiotic innovation, because they assume homogenous evolutionary processes across millions of years. Here we use a recently developed, heterogeneous and quantitative phylogenetic framework to study the origin of the symbiosis between angiosperms and nitrogen-fixing (N2) bacterial symbionts housed in nodules. We compile the largest database of global nodulating plant species and reconstruct the symbiosis' evolution. We identify a single, cryptic evolutionary innovation driving symbiotic N2-fixation evolution, followed by multiple gains and losses of the symbiosis, and the subsequent emergence of 'stable fixers' (clades extremely unlikely to lose the symbiosis). Originating over 100 MYA, this innovation suggests deep homology in symbiotic N2-fixation. Identifying cryptic innovations on the tree of life is key to understanding the evolution of complex traits, including symbiotic partnerships. PMID:24912610

  16. Improved Real-Time Monitoring Using Multiple Expert Systems

    NASA Technical Reports Server (NTRS)

    Schwuttke, Ursula M.; Angelino, Robert; Quan, Alan G.; Veregge, John; Childs, Cynthia

    1993-01-01

    Monitor/Analyzer of Real-Time Voyager Engineering Link (MARVEL) computer program implements combination of techniques of both conventional automation and artificial intelligence to improve monitoring of complicated engineering system. Designed to support ground-based operations of Voyager spacecraft, also adapted to other systems. Enables more-accurate monitoring and analysis of telemetry, enhances productivity of monitoring personnel, reduces required number of such personnel by performing routine monitoring tasks, and helps ensure consistency in face of turnover of personnel. Programmed in C language and includes commercial expert-system software shell also written in C.

  17. Improving MTF measurements of under-sampled optical systems

    NASA Astrophysics Data System (ADS)

    LaVeigne, Joseph D.; Burks, Stephen D.

    2009-05-01

    The modulation transfer function (MTF) of optical systems is often derived by taking the Fourier transform (FT) of a measured line spread function. Recently, methods of performing Fourier transforms that are common in infrared spectroscopy have been applied to MTF calculations. Proper apodization and phase correction have been shown to improve MTF calculations in optical systems. In this paper these methods as well as another filtering algorithm based on phase are applied to under-sampled optical systems. Results, both with and without the additional processing are presented and the differences are discussed.

  18. Lehigh Southwest Cement Company: Compressed Air System Improvement Saves Energy

    SciTech Connect

    2003-10-01

    In 2001, Lehigh Southwest Cement Company improved the compressed air system at its cement plant in Tehachapi, California. Consequently, the system was able to operate more efficiently with less compressor capacity and at a lower system pressure. The project yielded total annual savings of 895,000 kWh and $199,000. The initial project cost was $417,000, but Southern California Edison provided a $90,000 incentive payment to reduce the cost to $327,000. Simple payback was about 20 months.

  19. Electric motor systems in developing countries: Opportunities for efficiency improvement

    SciTech Connect

    Meyers, S.; Monahan, P.; Lewis, P.; Greenberg, S.; Nadel, S.

    1993-08-01

    This report presents an overview of the current status and efficiency improvement potential of industrial motor systems in developing countries. Better management of electric motor systems is of particular relevance in developing countries, where improved efficiency can lead to increased productivity and slower growth in electricity demand. Motor systems currently consume some 65--80% of the industrial electricity in developing countries. Drawing on studies from Thailand, India, Brazil, China, Pakistan, and Costa Rica, we describe potential efficiency gains in various parts of the motor system, from the electricity delivery system through the motor to the point where useful work is performed. We report evidence of a significant electricity conservation potential. Most of the efficiency improvement methods we examine are very cost-effective from a societal viewpoint, but are generally not implemented due to various barriers that deter their adoption. Drawing on experiences in North America, we discuss a range of policies to overcome these barriers, including education, training, minimum efficiency standards, motor efficiency testing protocols, technical assistance programs, and financial incentives.

  20. PTF 11kx: a type Ia supernova with a symbiotic nova progenitor.

    PubMed

    Dilday, B; Howell, D A; Cenko, S B; Silverman, J M; Nugent, P E; Sullivan, M; Ben-Ami, S; Bildsten, L; Bolte, M; Endl, M; Filippenko, A V; Gnat, O; Horesh, A; Hsiao, E; Kasliwal, M M; Kirkman, D; Maguire, K; Marcy, G W; Moore, K; Pan, Y; Parrent, J T; Podsiadlowski, P; Quimby, R M; Sternberg, A; Suzuki, N; Tytler, D R; Xu, D; Bloom, J S; Gal-Yam, A; Hook, I M; Kulkarni, S R; Law, N M; Ofek, E O; Polishook, D; Poznanski, D

    2012-08-24

    There is a consensus that type Ia supernovae (SNe Ia) arise from the thermonuclear explosion of white dwarf stars that accrete matter from a binary companion. However, direct observation of SN Ia progenitors is lacking, and the precise nature of the binary companion remains uncertain. A temporal series of high-resolution optical spectra of the SN Ia PTF 11kx reveals a complex circumstellar environment that provides an unprecedentedly detailed view of the progenitor system. Multiple shells of circumstellar material are detected, and the SN ejecta are seen to interact with circumstellar material starting 59 days after the explosion. These features are best described by a symbiotic nova progenitor, similar to RS Ophiuchi. PMID:22923575

  1. An improved authentication scheme for telecare medicine information systems.

    PubMed

    Wei, Jianghong; Hu, Xuexian; Liu, Wenfen

    2012-12-01

    The telecare medicine information system enables or supports health-care delivery services. In order to safeguard patients' privacy, such as telephone number, medical record number, health information, etc., a secure authentication scheme will thus be in demand. Recently, Wu et al. proposed a smart card based password authentication scheme for the telecare medicine information system. Later, He et al. pointed out that Wu et al.'s scheme could not resist impersonation attacks and insider attacks, and then presented a new scheme. In this paper, we show that both of them fail to achieve two-factor authentication as smart card based password authentication schemes should achieve. We also propose an improved authentication scheme for the telecare medicine information system, and demonstrate that the improved one satisfies the security requirements of two-factor authentication and is also efficient. PMID:22374237

  2. Symbiotic Performance of Diverse Frankia Strains on Salt-Stressed Casuarina glauca and Casuarina equisetifolia Plants

    PubMed Central

    Ngom, Mariama; Gray, Krystelle; Diagne, Nathalie; Oshone, Rediet; Fardoux, Joel; Gherbi, Hassen; Hocher, Valérie; Svistoonoff, Sergio; Laplaze, Laurent; Tisa, Louis S.; Sy, Mame O.; Champion, Antony

    2016-01-01

    Symbiotic nitrogen-fixing associations between Casuarina trees and the actinobacteria Frankia are widely used in agroforestry in particular for salinized land reclamation. The aim of this study was to analyze the effects of salinity on the establishment of the actinorhizal symbiosis between C. glauca and two contrasting Frankia strains (salt sensitive; CcI3 vs. salt tolerant; CeD) and the role of these isolates in the salt tolerance of C. glauca and C. equisetifolia plants. We show that the number of root nodules decreased with increasing salinity levels in both plants inoculated with CcI3 and CeD. Nodule formation did not occur in seedlings inoculated with CcI3 and CeD, at NaCl concentrations above 100 and 200 mM, respectively. Salinity also affected the early deformation of plant root hairs and reduced their number and size. In addition, expression of symbiotic marker Cg12 gene, which codes for a subtilase, was reduced at 50 mM NaCl. These data suggest that the reduction of nodulation in C. glauca under salt stress is in part due to inhibition of early mechanisms of infection. We also show that prior inoculation of C. glauca and C. equisetifolia with Frankia strains CcI3 and CeD significantly improved plant height, dry biomass, chlorophyll and proline contents at all levels of salinity tested, depending on the Casuarina-Frankia association. There was no correlation between in vitro salt tolerance of Frankia strains and efficiency in planta under salt-stressed conditions. Our results strongly indicate that increased N nutrition, photosynthesis potential and proline accumulation are important factors responsible for salt tolerance of nodulated C. glauca and C. equisetifolia.

  3. UV-protectant metabolites from lichens and their symbiotic partners.

    PubMed

    Nguyen, Khanh-Hung; Chollet-Krugler, Marylène; Gouault, Nicolas; Tomasi, Sophie

    2013-12-01

    Lichens are structurally complex symbiotic organisms that are exposed to a wide variety of external conditions (extreme temperatures, desiccation, UV radiation, etc.). These poikilohydric organisms have developed various mechanisms of photoprotection, such as light scattering, radiation screening, thermal dissipation, activation of antioxidant defense and macromolecules and membrane repair. These unique organisms produce a vast array of compounds, with more than 1000 secondary metabolites known. An important protective mechanism of lichens is the production of UV screening compounds, such as phenolic compounds (depsidones, depsides, diphenyl ethers), anthraquinones, xanthones or shikimic acid derivatives (calycin, mycosporines, scytonemin). Due to the harmful effects of the UVA wavelengths of sunlight, the search for new sunscreens remains important. We herein propose a review that focuses on the UV protectants from lichens and their symbiotic partners (lichenized fungi, green alga, cyanobacteria). In fact, lichens produce unique and/or efficient UV filters such as depsidones (lobaric acid, pannarin, etc.), depsides (atranorin, gyrophoric acid, etc.), diphenyl ethers (epiphorellic acids, buellin), bisxanthones (secalonic acids, etc.), mycosporines and MAAs, scytonemin along with classical pigments (melanin, carotenoids). We propose to classify these compounds with regard to their chemical structures and review the physicochemical properties that act as UV filters. While the most abundant lichen polyfunctionalized aromatic compounds, belonging to orsellinic derivatives, are UVB screens, these organisms produce strong UVA filters, e.g., calycin (pulvinic acid derivatives), bisxanthones (secalonic acids), scytonemin or mycosporines and MAAs with the latter ones exhibiting attractive properties as photoprotectants. PMID:24170172

  4. A statistical anomaly indicates symbiotic origins of eukaryotic membranes

    PubMed Central

    Bansal, Suneyna; Mittal, Aditya

    2015-01-01

    Compositional analyses of nucleic acids and proteins have shed light on possible origins of living cells. In this work, rigorous compositional analyses of ∼5000 plasma membrane lipid constituents of 273 species in the three life domains (archaea, eubacteria, and eukaryotes) revealed a remarkable statistical paradox, indicating symbiotic origins of eukaryotic cells involving eubacteria. For lipids common to plasma membranes of the three domains, the number of carbon atoms in eubacteria was found to be similar to that in eukaryotes. However, mutually exclusive subsets of same data show exactly the opposite—the number of carbon atoms in lipids of eukaryotes was higher than in eubacteria. This statistical paradox, called Simpson's paradox, was absent for lipids in archaea and for lipids not common to plasma membranes of the three domains. This indicates the presence of interaction(s) and/or association(s) in lipids forming plasma membranes of eubacteria and eukaryotes but not for those in archaea. Further inspection of membrane lipid structures affecting physicochemical properties of plasma membranes provides the first evidence (to our knowledge) on the symbiotic origins of eukaryotic cells based on the “third front” (i.e., lipids) in addition to the growing compositional data from nucleic acids and proteins. PMID:25631820

  5. Symbiotic symbolization by hand and mouth in sign language*

    PubMed Central

    Sandler, Wendy

    2010-01-01

    Current conceptions of human language include a gestural component in the communicative event. However, determining how the linguistic and gestural signals are distinguished, how each is structured, and how they interact still poses a challenge for the construction of a comprehensive model of language. This study attempts to advance our understanding of these issues with evidence from sign language. The study adopts McNeill’s criteria for distinguishing gestures from the linguistically organized signal, and provides a brief description of the linguistic organization of sign languages. Focusing on the subcategory of iconic gestures, the paper shows that signers create iconic gestures with the mouth, an articulator that acts symbiotically with the hands to complement the linguistic description of objects and events. A new distinction between the mimetic replica and the iconic symbol accounts for the nature and distribution of iconic mouth gestures and distinguishes them from mimetic uses of the mouth. Symbiotic symbolization by hand and mouth is a salient feature of human language, regardless of whether the primary linguistic modality is oral or manual. Speakers gesture with their hands, and signers gesture with their mouths. PMID:20445832

  6. Spectroscopic observations of D-type symbiotic stars

    NASA Astrophysics Data System (ADS)

    Pereira, C. B.; Landaberry, S. J. C.; Junqueira, S.

    1998-05-01

    Observations of five D-type symbiotics are presented: three oxygen Mira (He2-38, H2-38 and H1-36) and two carbon Mira symbiotics (AS 210 and SS 38). The observations in the spectral range between 3200Angstroms, and 7400Angstroms, show the presence of several emission lines in various states of excitation. A line list is provided with their suggested identifications. Several parameters were derived for each object: interstellar reddening as determined from Balmer decrement and Heii lines, temperature and electronic density, abundance ratios of Ne/O, Ar/O, Fe/Ne, N/O and He/H. We found nitrogen enrichment while for the other elements their abundances are compatible with solar, except iron which is depleted. We did not detect significant changes in the line and in the continuos spectra of the stars analyzed here, except for He2-38, which increased its degree of excitation compared to Allen's (1984) catalogue. Based on observations made with the 1.52m telescope at the European Southern Observatory (La Silla, Chile) under the agreement with the CNPq-Observatório Nacional (Brazil)

  7. Unraveling the nitrogen isotopic signature of symbiotic corals

    NASA Astrophysics Data System (ADS)

    Devlin, Q.; Swart, P. K.; Altabet, M. A.

    2013-12-01

    Coral reefs thrive in shallow, tropical, low nutrient waters. Nutrient inputs to a reef environment are often interpreted by measuring the nitrogen isotopic composition of reef organisms. The δ15N signature of scleractinian corals has been historically measured to assess the presence of anthropogenic influences such as sewage and fertilizer runoff. The majority of reef building corals form a symbiotic partnership with the dinoflagellate algae, Symbiodinium microadriaticum. The δ15N signature of symbiotic corals is complex as it is not only dependent on nitrogen acquisition by the coral, but also by the algal symbionts that reside within the gastrodermal tissue layer. The relationship between the δ15N of dissolved inorganic nitrogen (DIN) and the δ15N of coral tissue has not been established. The aim of this study is to identify considerations necessary when interpreting nitrogen sources based on δ15N of coral tissue. Incubations were carried out in order to measure isotopic fractionation associated with nitrate and ammonium incorporation by the Pacific branching coral, Pocillopora damicornis. We investigated the dependence of nitrogen isotope fractionation on species of DIN (nitrate or ammonium), concentration of DIN (range: 1-50 μM N), genetic diversity of algal symbionts (clade C or clade D) and light levels.

  8. Photophysiology and daily primary production of a temperate symbiotic gorgonian.

    PubMed

    Ferrier-Pagès, C; Reynaud, S; Béraud, E; Rottier, C; Menu, D; Duong, G; Gévaert, F

    2015-01-01

    Gorgonians are one of the most important benthic components of tropical and temperate areas, and play a fundamental role as ecosystem engineers. Although global warming and pollution increasingly threaten them, the acquisition of nutrients, which is a key process in fitness and stress resistance, has been poorly investigated in such species. This study has thus used an advanced in situ incubation chamber for the first time with gorgonians, to assess the daily acquisition of nutrients and the photophysiology of the Mediterranean symbiotic species, Eunicella singularis. The xanthophyll cycle was assessed in parallel. This work has revealed that E. singularis presents a different functioning than the Mediterranean symbiotic corals. This gorgonian indeed relies on both autotrophy and heterotrophy in summer to optimize its energetic budget, while corals mainly shift to autotrophy for their respiratory needs and tissue growth. In addition, although E. singularis lives in the same depths/locations, and harbours the same symbiont genotype than the corals, the photosynthetic performances of their respective symbionts are significantly different. Indeed, E. singularis acquired 2-3 times less autotrophic carbon from its symbionts than corals, but maintained a positive carbon budget by reducing respiration rates, and by presenting maximal photosynthetic rates throughout the day, suggesting a very efficient light utilization. Almost no photoinhibition was observed under very high light levels, because of the induction of a xanthophyll photoprotection process. These results help understanding why gorgonians often dominate many benthic ecosystems. PMID:25255987

  9. A slowly evolving host moves first in symbiotic interactions

    NASA Astrophysics Data System (ADS)

    Damore, James; Gore, Jeff

    2011-03-01

    Symbiotic relationships, both parasitic and mutualistic, are ubiquitous in nature. Understanding how these symbioses evolve, from bacteria and their phages to humans and our gut microflora, is crucial in understanding how life operates. Often, symbioses consist of a slowly evolving host species with each host only interacting with its own sub-population of symbionts. The Red Queen hypothesis describes coevolutionary relationships as constant arms races with each species rushing to evolve an advantage over the other, suggesting that faster evolution is favored. Here, we use a simple game theoretic model of host- symbiont coevolution that includes population structure to show that if the symbionts evolve much faster than the host, the equilibrium distribution is the same as it would be if it were a sequential game where the host moves first against its symbionts. For the slowly evolving host, this will prove to be advantageous in mutualisms and a handicap in antagonisms. The model allows for symbiont adaptation to its host, a result that is robust to changes in the parameters and generalizes to continuous and multiplayer games. Our findings provide insight into a wide range of symbiotic phenomena and help to unify the field of coevolutionary theory.

  10. Dark CO/sub 2/ fixation and amino acid metabolism in symbiotic N/sub 2/-fixing systems. Labeling studies with /sup 14/C and /sup 13/N-labeled tracers. [Roots of soybean plants and alders

    SciTech Connect

    Coker, G.T. III

    1982-01-01

    Amino acid metabolism was examined by monitoring the amino acids labeled with (/sup 14/C) incorporated during dark CO/sub 2/ fixation and with (/sup 13/N) incorporated from /sup 13/NH/sub 4/+, /sup 13/NO/sub 3/- or (/sup 13/N)N/sub 2/. Label from /sup 14/CO/sub 2/ was directly incorporated in soybean roots and the N/sub 2/-fixing root nodules of soybeans and alders. The products of dark CO/sub 2/ fixation were primarily amino and organic acids. The distribution of label incorporated from /sup 14/CO/sub 2/ into amino acids depended on the plant species and the nitrigen source. The major labeled amino acids in roots and nodules of soybean plants dependent on N/sub 2/ were aspartate and glutamate; in alder nodules, citrulline; in roots of soybean plants treated with NO/sub 3/-, asparagine; and in roots of soybean plants treated with NH/sub 4/+, asparagine and glutamine. Asparagine was the major amino acid transported out of the soybean root system. Experiments indicated that asparagine was synthesized directly from aspartate. After exposure to /sup 14/CO/sub 2/, the specific activity of glutamine was consistently higher than that of glutamate in soybean nodules and roots of plants treated with NO/sub 3/-. This was taken as evidence that there were two pools of glutamate, only one of which was associated with glutamine synthesis. Alder and soybean nodules and roots were incubated with /sup 13/N-labeled tracers. Those tissues incubated with /sup 13/NH/sub 4/+ had a higher ratio of (/sup 13/N)glutamine to (/sup 13/N)glutamate that similar tissues exposed to /sup 13/NO/sub 3/- or (/sup 13/N)N/sub 2/. An explanation for these results based on the relative rates of glutamine and glutamate synthesis is discussed.

  11. Multimachine system transient stability improvement using transient power system stabilizers (TPSS)

    SciTech Connect

    Musaazi, M.K.; Johnson, R.B.I.; Cory, B.J.

    1986-12-01

    Power system stabilizers (PSS) have been designed and installed to improve the dynamic (small signal) response of multimachine systems. This paper presents the theory and test results for improving the transient (large disturbance) behaviour of a multimachine system by supplementing the conventional PSS with a transient power system stabilizer (TPSS). Each generator unit is fitted with a TPSS which, after computation, injects supplementary control signals into both the automatic voltage regulator (AVR) and speed governor control loops.

  12. A simple prioritisation system to improve the electronic handover.

    PubMed

    Ah-Kye, Laura; Moore, Madeline

    2015-01-01

    The General Medical Council (GMC) states, "A well managed, thorough and organized handover is crucial for ensuring the quality and safety for patient care," and in their guidance on safe handover the British Medical Association (BMA) advised that "clinically unstable patients are known to the senior and covering clinicians; tasks should be prioritised; plans for further care are put in place; unstable patients are reviewed." The orthopaedic department at King's College Hospital, a busy major trauma centre in London, UK, has a significantly reduced workforce during the weekend. The general consensus was that the ward round was taking too long, giving the foundation year one (FY1) doctor very little time to commit to other ward jobs and reviewing unstable patients, making it a stressful and challenging environment. The electronic patient record (EPR), an electronic programme available on all Trust computers, is already a very reliable way to allow safe handover of information via a central electronic database. However it has limitations in clearly prioritising more unstable patients from those needing routine review. We created an easily identifiable traffic light coding system that could be simply incorporated into the electronic handover that was re-reviewed and finalised in order to improve the ability to prioritise patients for senior review. This in turn would directly impact the efficiency of the ward round and improve patient safety. Our immediate results demonstrated the efficiency of the ward round improved in all parameters: time to complete the ward round improved from 7.1% to 50%; prioritisation and ability to highlight the clinical urgency for patient review improved from 15.4% to 100%; and more notably, the clinician's impression of patient safety improved from 38.5% to 100%. Overall the introduction of an uncomplicated traffic light system provided an effective addition to the electronic handover structure aimed to allow patient prioritisation and

  13. A simple prioritisation system to improve the electronic handover

    PubMed Central

    Ah-kye, Laura; Moore, Madeline

    2015-01-01

    The General Medical Council (GMC) states, “A well managed, thorough and organized handover is crucial for ensuring the quality and safety for patient care,” and in their guidance on safe handover the British Medical Association (BMA) advised that “clinically unstable patients are known to the senior and covering clinicians; tasks should be prioritised; plans for further care are put in place; unstable patients are reviewed.” The orthopaedic department at King's College Hospital, a busy major trauma centre in London, UK, has a significantly reduced workforce during the weekend. The general consensus was that the ward round was taking too long, giving the foundation year one (FY1) doctor very little time to commit to other ward jobs and reviewing unstable patients, making it a stressful and challenging environment. The electronic patient record (EPR), an electronic programme available on all Trust computers, is already a very reliable way to allow safe handover of information via a central electronic database. However it has limitations in clearly prioritising more unstable patients from those needing routine review. We created an easily identifiable traffic light coding system that could be simply incorporated into the electronic handover that was re-reviewed and finalised in order to improve the ability to prioritise patients for senior review. This in turn would directly impact the efficiency of the ward round and improve patient safety. Our immediate results demonstrated the efficiency of the ward round improved in all parameters: time to complete the ward round improved from 7.1% to 50%; prioritisation and ability to highlight the clinical urgency for patient review improved from 15.4% to 100%; and more notably, the clinician's impression of patient safety improved from 38.5% to 100%. Overall the introduction of an uncomplicated traffic light system provided an effective addition to the electronic handover structure aimed to allow patient prioritisation

  14. Design evaluation of an improved indirect evaporative cooling system

    NASA Astrophysics Data System (ADS)

    Dunn, J. R.

    1982-04-01

    The results of an investigation of an improved indirect evaporative cooling (TRC) system are presented. A cooling system concept which combines an indirect evaporative cooling unit with a conventional vapor compression refrigeration system was studied. In this system, initial cooling of outside air is performed in the IEC unit with additional cooling taking place across the evaporator coil of the conventional refrigeration unit before delivery to the conditioned space. The condenser coil rejects heat to the secondary (humidified) air stream of the IEC before it is discharged outdoors. A simulation model was developed to predict the performance characteristics of the concept for additional conditions beyond those used in the experimental test program. Principal output parameters from both the test program and simulation model included delivery air temperature, cooling capacity, and system COP.

  15. Head-aimed vision system improves tele-operated mobility

    NASA Astrophysics Data System (ADS)

    Massey, Kent

    2004-12-01

    A head-aimed vision system greatly improves the situational awareness and decision speed for tele-operations of mobile robots. With head-aimed vision, the tele-operator wears a head-mounted display and a small three axis head-position measuring device. Wherever the operator looks, the remote sensing system "looks". When the system is properly designed, the operator's occipital lobes are "fooled" into believing that the operator is actually on the remote robot. The result is at least a doubling of: situational awareness, threat identification speed, and target tracking ability. Proper system design must take into account: precisely matching fields of view; optical gain; and latency below 100 milliseconds. When properly designed, a head-aimed system does not cause nausea, even with prolonged use.

  16. Improved Stochastic Subspace System Identification for Structural Health Monitoring

    NASA Astrophysics Data System (ADS)

    Chang, Chia-Ming; Loh, Chin-Hsiung

    2015-07-01

    Structural health monitoring acquires structural information through numerous sensor measurements. Vibrational measurement data render the dynamic characteristics of structures to be extracted, in particular of the modal properties such as natural frequencies, damping, and mode shapes. The stochastic subspace system identification has been recognized as a power tool which can present a structure in the modal coordinates. To obtain qualitative identified data, this tool needs to spend computational expense on a large set of measurements. In study, a stochastic system identification framework is proposed to improve the efficiency and quality of the conventional stochastic subspace system identification. This framework includes 1) measured signal processing, 2) efficient space projection, 3) system order selection, and 4) modal property derivation. The measured signal processing employs the singular spectrum analysis algorithm to lower the noise components as well as to present a data set in a reduced dimension. The subspace is subsequently derived from the data set presented in a delayed coordinate. With the proposed order selection criteria, the number of structural modes is determined, resulting in the modal properties. This system identification framework is applied to a real-world bridge for exploring the feasibility in real-time applications. The results show that this improved system identification method significantly decreases computational time, while qualitative modal parameters are still attained.

  17. Clustering-based urbanisation to improve enterprise information systems agility

    NASA Astrophysics Data System (ADS)

    Imache, Rabah; Izza, Said; Ahmed-Nacer, Mohamed

    2015-11-01

    Enterprises are daily facing pressures to demonstrate their ability to adapt quickly to the unpredictable changes of their dynamic in terms of technology, social, legislative, competitiveness and globalisation. Thus, to ensure its place in this hard context, enterprise must always be agile and must ensure its sustainability by a continuous improvement of its information system (IS). Therefore, the agility of enterprise information systems (EISs) can be considered today as a primary objective of any enterprise. One way of achieving this objective is by the urbanisation of the EIS in the context of continuous improvement to make it a real asset servicing enterprise strategy. This paper investigates the benefits of EISs urbanisation based on clustering techniques as a driver for agility production and/or improvement to help managers and IT management departments to improve continuously the performance of the enterprise and make appropriate decisions in the scope of the enterprise objectives and strategy. This approach is applied to the urbanisation of a tour operator EIS.

  18. Titan I propulsion system modeling and possible performance improvements

    NASA Astrophysics Data System (ADS)

    Giusti, Oreste

    This thesis features the Titan I propulsion systems and offers data-supported suggestions for improvements to increase performance. The original propulsion systems were modeled both graphically in CAD and via equations. Due to the limited availability of published information, it was necessary to create a more detailed, secondary set of models. Various engineering equations---pertinent to rocket engine design---were implemented in order to generate the desired extra detail. This study describes how these new models were then imported into the ESI CFD Suite. Various parameters are applied to these imported models as inputs that include, for example, bi-propellant combinations, pressure, temperatures, and mass flow rates. The results were then processed with ESI VIEW, which is visualization software. The output files were analyzed for forces in the nozzle, and various results were generated, including sea level thrust and ISP. Experimental data are provided to compare the original engine configuration models to the derivative suggested improvement models.

  19. Benefits of an improved wheat crop information system

    NASA Technical Reports Server (NTRS)

    Kinne, I. L.

    1976-01-01

    The ECON work and the results of the independent reviews are summarized. Attempts are made to put this information into layman's terms and to present the benefits that can realistically be expected from a LANDSAT-type remote sensing system. Further the mechanisms by which these benefits can be expected to accrue are presented. The benefits are given including the nature of expected information improvements, how and why they can lead to benefits to society, and the estimated magnitude of the expected benefits. A brief description is presented of the ECON models, how they work, their results, and a summary of the pertinent aspects of each review. The ECON analyses show that substantial benefits will accrue from implementation of an improved wheat crop information system based on remote sensing.

  20. Improved Thermal-Insulation Systems for Low Temperatures

    NASA Technical Reports Server (NTRS)

    Fesmire, James E.; Augustynowicz, Stanislaw D.

    2003-01-01

    Improved thermal-insulation materials and structures and the techniques for manufacturing them are undergoing development for use in low-temperature applications. Examples of low-temperature equipment for which these thermal insulation systems could provide improved energy efficiency include storage tanks for cryogens, superconducting electric-power-transmission equipment, containers for transport of food and other perishable commodities, and cold boxes for low-temperature industrial processes. These systems could also be used to insulate piping used to transfer cryogens and other fluids, such as liquefied natural gas, refrigerants, chilled water, crude oil, or low-pressure steam. The present thermal-insulation systems are layer composites based partly on the older class of thermal-insulation systems denoted generally as multilayer insulation (MLI). A typical MLI structure includes an evacuated jacket, within which many layers of radiation shields are stacked or wrapped close together. Low-thermal-conductivity spacers are typically placed between the reflection layers to keep them from touching. MLI can work very well when a high vacuum level (less than 10(exp-4) torr) is maintained and utmost care is taken during installation, but its thermal performance deteriorates sharply as the pressure in the evacuated space rises into the soft vacuum range [pressures greater than 0.1 torr (greater than 13 Pa)]. In addition, the thermal performance of MLI is extremely sensitive to mechanical compression and edge effects and can easily decrease from one to two orders of magnitude from its ideal value even when the MLI is kept under high vacuum condition. The present thermal-insulation systems are designed to perform well under soft vacuum level, in particular the range of 1 to 10 torr. They are also designed with larger interlayer spacings to reduce vulnerability to compression (and consequent heat leak) caused by installation and use. The superiority of these systems is the

  1. Improving Security in the ATLAS PanDA System

    NASA Astrophysics Data System (ADS)

    Caballero, J.; Maeno, T.; Nilsson, P.; Stewart, G.; Potekhin, M.; Wenaus, T.

    2011-12-01

    The security challenges faced by users of the grid are considerably different to those faced in previous environments. The adoption of pilot jobs systems by LHC experiments has mitigated many of the problems associated with the inhomogeneities found on the grid and has greatly improved job reliability; however, pilot jobs systems themselves must then address many security issues, including the execution of multiple users' code under a common 'grid' identity. In this paper we describe the improvements and evolution of the security model in the ATLAS PanDA (Production and Distributed Analysis) system. We describe the security in the PanDA server which is in place to ensure that only authorized members of the VO are allowed to submit work into the system and that jobs are properly audited and monitored. We discuss the security in place between the pilot code itself and the PanDA server, ensuring that only properly authenticated workload is delivered to the pilot for execution. When the code to be executed is from a 'normal' ATLAS user, as opposed to the production system or other privileged actor, then the pilot may use an EGEE developed identity switching tool called gLExec. This changes the grid proxy available to the job and also switches the UNIX user identity to protect the privileges of the pilot code proxy. We describe the problems in using this system and how they are overcome. Finally, we discuss security drills which have been run using PanDA and show how these improved our operational security procedures.

  2. SLR system improvement for GIOVE-A satellite observation

    NASA Astrophysics Data System (ADS)

    Zhao, You; Fan, Cunbo; Han, Xingwei; Yang, Dingjiang; Chen, Nianjiang; Xue, Feng; Geng, Lin

    2008-03-01

    Galileo system consists of 27 satellites distributed in three uniformly separated planes. At the end of 2005, one satellite, Galileo In-Orbit Validation Element-A (GIOVE-A), was launched as planned into an MEO with an altitude of 23,260 kilometers. Carrying a payload of rubidium clocks, signal-generation units, and a phase-array antenna of individual L-band elements. GIOVE-A started broadcasting on January 28, 2006, securing the frequencies allocated by the ITU for Galileo. Performance of the on-board atomic clocks, antenna infrastructure, and signal properties is evaluated through precise orbit determination, supported by Satellite Laser Ranging (SLR), an independent high-precision range measurement technique for orbit determination based on a global network of stations that measure the round-trip flight-time of ultra short laser pulses to satellites equipped with laser retro reflector arrays (LRAs). SLR provides instantaneous range measurements of millimeter-level precision which can be compiled to provide accurate orbits and to measure the on-board clock error. Given the importance of SLR data for the characterization of the GIOVE-A clocks, the Changchun SLR station in northeast China was selected among the Chinese stations contributing to the ILRS because it had demonstrated strong MEO satellite tracking; collocation with an existing International GPS Service station; and good weather conditions. This paper introduces the SLR system improvement for tracking GIOVE-A satellite in Changchun station. During the more than two months improvement, the new servo and encoder systems were installed, primary mirror, second mirror and some other mirrors have been cleaned and recoated, and the laser system was adjusted in order to improve the laser efficiency and output energy. The paper gives out the improvement results, and the GIOVE-A satellite observation results.

  3. Health care systems redesign project to improve dysphagia screening.

    PubMed

    Daggett, Virginia S; Woodward-Hagg, Heather; Damush, Teresa M; Plue, Laurie; Russell, Scott; Allen, George; Williams, Linda S; Chumbler, Neale R; Bravata, Dawn M

    2015-01-01

    The purpose of this project was to improve dysphagia-screening processes in a tertiary Veterans Affairs Medical Center. The dysphagia-screening tool was redesigned on the basis of frontline clinician feedback, clinical guidelines, user satisfaction, and multidisciplinary expertise. The revised tool triggered a speech-language consult for positive screens and demonstrated higher scores in user satisfaction and task efficiency. Systems redesign processes were effective for redesigning the tool and implementing practice changes with clinicians involved in dysphagia screening. PMID:25463001

  4. NASA's Marshall Space Flight Center Improves Cooling System Performance

    SciTech Connect

    2011-02-22

    National Aeronautics and Space Administration’s (NASA) Marshall Space Flight Center (MSFC) has a longstanding sustainability program that revolves around energy and water efficiency as well as environmental protection. MSFC identified a problematic cooling loop with six separate compressor heat exchangers and a history of poor efficiency. The facility engineering team at MSFC partnered with Flozone Services, Incorporated to implement a comprehensive water treatment platform to improve the overall efficiency of the system.

  5. An Improved B+ Tree for Flash File Systems

    NASA Astrophysics Data System (ADS)

    Havasi, Ferenc

    Nowadays mobile devices such as mobile phones, mp3 players and PDAs are becoming evermore common. Most of them use flash chips as storage. To store data efficiently on flash, it is necessary to adapt ordinary file systems because they are designed for use on hard disks. Most of the file systems use some kind of search tree to store index information, which is very important from a performance aspect. Here we improved the B+ search tree algorithm so as to make flash devices more efficient. Our implementation of this solution saves 98%-99% of the flash operations, and is now the part of the Linux kernel.

  6. A Novel Green Cloud Computing Framework for Improving System Efficiency

    NASA Astrophysics Data System (ADS)

    Lin, Chen

    As the prevalence of Cloud computing continues to rise, the need for power saving mechanisms within the Cloud also increases. In this paper we have presented a novel Green Cloud framework for improving system efficiency in a data center. To demonstrate the potential of our framework, we have presented new energy efficient scheduling, VM system image, and image management components that explore new ways to conserve power. Though our research presented in this paper, we have found new ways to save vast amounts of energy while minimally impacting performance.

  7. Symbiotic Nuclear—Coal Systems for Production of Liquid Fuels

    NASA Astrophysics Data System (ADS)

    Taczanowski, S.

    The notion of safety is not confined to the technological or non-proliferation aspects. It covers also the elements of energy policy: irrational reactions of societies, emotions, egoistic interests of more or less powerful pressure of economical and external political factors. One should be conscious that the country's privilege of being equipped by the Nature with rich resources of oil or gas is not solely economical, but even more a political one. Simultaneously, the gradual depletion of world hydrocarbons that draws behind irrevocable price increase has to be expected within the time scale of exploitation of power plants (now amounted to ~60 years). Therefore consequences of energy policy last much longer than the perspectives the political or economical decision makers are planning and acting within and the public is expecting successes and finally evaluating them. The world oil and gas resources are geopolitically very non-uniformly distributed, in contrast to coal and uranium. Since the level of energy self-sufficiency of the EU is highest for coal, the old idea of synfuels production from coal is recalled. Yet, in view of limits to the CO2 emissions in the EU another method has to be used here than the conventional coal liquefaction just applied in China. Simultaneously, an interesting evolution of energy prices was be observed, namely an increase in that of motor fuels in contrast to that of electricity remaining well stable. This fact suggests that the use of electricity (mainly the off-peak load), generated without emissions of CO2 for production of liquid fuels can prove reasonable. Thus, the essence of the presented idea of coal-nuclear symbiosis lies in the supply of energy in the form of H2, necessary for this process, from a nuclear reactor. Particularly, in the present option H2 is obtained by electrolytic water splitting supplying also O2 as a precious by-product in well mature and commercially available already since decades, Light Water Reactors (LWRs). The direct coal hydrogenation (Bergius method) has been proposed as the optimum process for liquid fuels production, as distinct by the best hydrogen economy, thus reducing the consumption of need nuclear energy. The present concept allows for simultaneous achievement of a number of aims: production of motor fuels without CO2 emissions (thus without carbon tax) based upon domestic energy carriers — coals, supply of the electricity produced in the nuclear power plant to the national grid to cover the peak demand. Such concept broadens the palette of liquid fuels supply, thus heightens energy safety of the country or e.g. whole of the EU. In an emergency case (for instance — disturbances of gas deliveries) the supply of produced H2 directly to the gas grid is also not excluded too. The performed preliminary cost evaluation indicates that the coal—nuclear symbiont can be well economic. Finally, the most radical option of coal-nuclear alliance is mentioned — the production of liquid fuels in the Fischer—Tropsch process from CO2 as a raw material sequestered from a coal power plant. The latter would use the oxy-combustion technique profiting on the O2 obtained earlier together with H2 what would facilitate the sequestration of CO2 at the plant. Unfortunately, this variant requires for reduction of CO2 to C much more hydrogen, achievable effectively in High Temperature Reactors commercially still unavailable. But on the basis of coal alone great resources — natural, technological and human of the coal sector can be best utilized too. Summarizing: the coal-nuclear synergy is the optimum far-sighted concept of safe development of the EU energy and fuels sector.

  8. Control systems improvements in a precision coordinate measuring machine

    NASA Astrophysics Data System (ADS)

    Douglass, S. S.; Babelay, E. F., Jr.; Igou, R. E.; Woodard, L. M.; Green, W. L.

    1981-09-01

    A conventional, manually driven Moore No. 3 coordinate measuring machine at the Oak Ridge Y-12 Plant is being upgraded to provide a continuous-path numerical control capability and simultaneously serve as a vehicle for testing new machine slide-control concepts. Besides new lead screw drive motors, an NC machine control unit, and a closed-loop servo system, the machine has also been equipped with vibration isolation, air-bearing slideways, and laser interferometric position feedback. The present conventional slide servo system will be replaced with a digital servo system wherein various feedback and compensation techniques can be realized through the use of a high speed, dedicated digital processor. The improvements to data are described with emphasis on identification and compensation of the slide control systems.

  9. Improving and Accelerating Drug Development for Nervous System Disorders

    PubMed Central

    Pankevich, Diana E.; Altevogt, Bruce M.; Dunlop, John; Gage, Fred H.; Hyman, Steve E.

    2014-01-01

    Advances in the neurosciences have placed the field in the position where it is poised to significantly reduce the burden of nervous system disorders. However, drug discovery, development and translation for nervous system disorders still pose many unique challenges. The key scientific challenges can be summarized as follows: mechanisms of disease, target identification and validation, predictive models, biomarkers for patient stratification and as endpoints for clinical trials, clear regulatory pathways, reliability and reproducibility of published data, and data sharing and collaboration. To accelerate nervous system drug development the Institute of Medicine’s Forum on Neuroscience and Nervous System Disorders has hosted a series of public workshops that brought together representatives of industry, government (including both research funding and regulatory agencies), academia, and patient groups to discuss these challenges and offer potential strategies to improve the translational neuroscience. PMID:25442933

  10. A method to improve the precision of measuring focusing system

    NASA Astrophysics Data System (ADS)

    Xu, Xiaoliang; An, Tao; Chen, Ke

    2015-10-01

    Most of the telescope focusing systems adopt the measuring distance method to focus the quick-moving target because the imaging position of moving target is constantly changing. The focusing system calculates the focal position, controls the motor according to the distance of the target. This focusing method has a faster focusing and a better real-time performance compared to the image focusing method based on the image quality. But restricted by the external environment, the precision of instruments and technical level, Distance measuring focus system(DMFS) generally have low precision, higher dynamic adjusting delay problem. This paper mainly analyses the main error sources affecting the accuracy of DMFS, aiming at the existing defects of commonly used current speed compensation method, put forward a kind of solution path delay lag method predicted method measuring focusing system, and then simulate it, the result shows that this method can greatly improve the precision of DMFS.

  11. Improved Controls for Fusion RF Systems. Final technical report

    SciTech Connect

    Casey, Jeffrey A.

    2011-11-08

    We have addressed the specific requirements for the integrated systems controlling an array of klystrons used for Lower Hybrid Current Drive (LHCD). The immediate goal for our design was to modernize the transmitter protection system (TPS) for LHCD on the Alcator C-Mod tokamak at the MIT Plasma Science and Fusion Center (MIT-PSFC). Working with the Alcator C-Mod team, we have upgraded the design of these controls to retrofit for improvements in performance and safety, as well as to facilitate the upcoming expansion from 12 to 16 klystrons. The longer range goals to generalize the designs in such a way that they will be of benefit to other programs within the international fusion effort was met by designing a system which was flexible enough to address all the MIT system requirements, and modular enough to adapt to a large variety of other requirements with minimal reconfiguration.

  12. Changes of cellular superficial configuration of symbiotic algae during cultivation from two anemones found in the South China Sea

    NASA Astrophysics Data System (ADS)

    Zhu, Baohua; Pan, Kehou; Wang, Guangce

    2008-02-01

    Symbiotic algae from two anemones, Radianthus macrodactylus and Stichodactyla mertensii, found in the South China Sea, were cultivated in ASP-8A medium in this study. Changes of superficial configuration of symbiotic algae during the cultivation were studied by means of a microscope and a scanning electron microscope (SEM). A number of small cavities appeared on the surfaces of symbiotic algae after they were cultivated for 10 h. The cavities enlarged and the cell contents were lost with extended cultivation. Our data suggested that the presence of cavities on symbiotic algae surfaces may be one of the main reasons for failure to culture symbiotic algae in an artificial medium.

  13. Soil management systems to improve water availability for plants

    NASA Astrophysics Data System (ADS)

    Klik, A.; Rosner, J.

    2009-04-01

    Due to climate change it is expected that the air temperature will increase and the amount as well as the variability of rainfall will change drastically within this century. Higher temperatures and fewer rainy days with more extreme events will increase the risk of surface runoff and erosion. This will lead to reduced soil water storage and therefore to a lower water use efficiency of plants. Soil and land management systems need to be applied and adapted to improve the amount of water stored in the soil and to ensure crop productivity functions of soils under changing climatic conditions. In a 14-yr. long field experiment, the effects of three soil management systems have been studied at three sites in Austria with respect to surface runoff, soil erosion, losses of nutrients and pesticides. Eight years after beginning of the project soil samples have been taken from different depth throughout the root zone to investigate the effects on soil properties. The results show that soil management systems with reduced tillage intensity are able to improve infiltration and soil water storage. More soil water enables plant development during longer dry periods and decreases amounts of irrigation. Overall, the higher water retention in the landscape improves the regional water balance and reduces environmental problems like soil erosion and nutrient and pesticide losses

  14. Electronic Equipment Proposal to Improve the Photovoltaic Systems Efficiency

    NASA Astrophysics Data System (ADS)

    Flores-Mena, J. E.; Juárez Morán, L. A.; Díaz Reyes, J.

    2011-05-01

    This paper reports a new technique proposal to improve the photovoltaic systems. It was made to design and implement an electronic system that will detect, capture, and transfer the maximum power of the photovoltaic (PV) panel to optimize the supplied power of a solar panel. The electronic system works on base technical proposal of electrical sweeping of electric characteristics using capacitive impedance. The maximum power is transformed and the solar panel energy is sent to an automotive battery. This electronic system reduces the energy lost originated when the solar radiation level decreases or the PV panel temperature is increased. This electronic system tracks, captures, and stores the PV module's maximum power into a capacitor. After, a higher voltage level step-up circuit was designed to increase the voltage of the PV module's maximum power and then its current can be sent to a battery. The experimental results show that the developed electronic system has 95% efficiency. The measurement was made to 50 W, the electronic system works rightly with solar radiation rate from 100 to 1,000 W m - 2 and the PV panel temperature rate changed from 1 to 75°C. The main advantage of this electronic system compared with conventional methods is the elimination of microprocessors, computers, and sophisticated numerical approximations, and it does not need any small electrical signals to track the maximum power. The proposed method is simple, fast, and it is also cheaper.

  15. Journal entries facilitating preprofessional scientific literacy and mutualistic symbiotic relationships

    NASA Astrophysics Data System (ADS)

    Vander Vliet, Valerie J.

    This study explored journal writing as an alternative assessment to promote the development of pre-professional scientific literacy and mutualistic symbiotic relationships between teaching and learning, instruction and assessment, and students and teachers. The larger context of this study is an action reaction project of the attempted transformation of a traditional first year undergraduate pre-professional biology class to sociocultural constructivist principles. The participants were commuter and residential, full and part-time students ranging in age from 18 to 27 and 18/21 were female. The backgrounds of the students varied considerably, ranging from low to upper middle income, including students of Black and Asian heritage. The setting was a medium-sized Midwestern university. The instructor has twenty years of experience teaching Biology at the college level. The data were analyzed using the constant comparative method and the development of grounded theory. The journal entries were analyzed as to their function and form in relationship to the development of multiple aspects of pre-professional scientific literacy. The perceptions of the students as to the significance of the use of journal entries were also determined through the analysis of their use of journal entries in their portfolios and statements in surveys and portfolios. The analysis revealed that journal entries promoted multiple aspects of pre-professional scientific literacy in both students and the instructor and facilitated the development of mutualistic symbiotic relationships between teaching and learning, instruction and assessment, and students and teachers. The function analysis revealed that the journal entries fulfilled the functions intended for the development of multiple aspects of pre-professional scientific literacy. The complexity of journal writing emerged from the form analysis, which revealed the multiple form elements inherent in journal entries. Students perceived journal

  16. Evolutionary signals of symbiotic persistence in the legume–rhizobia mutualism

    PubMed Central

    Werner, Gijsbert D. A.; Cornwell, William K.; Cornelissen, Johannes H. C.; Kiers, E. Toby

    2015-01-01

    Understanding the origins and evolutionary trajectories of symbiotic partnerships remains a major challenge. Why are some symbioses lost over evolutionary time whereas others become crucial for survival? Here, we use a quantitative trait reconstruction method to characterize different evolutionary stages in the ancient symbiosis between legumes (Fabaceae) and nitrogen-fixing bacteria, asking how labile is symbiosis across different host clades. We find that more than half of the 1,195 extant nodulating legumes analyzed have a high likelihood (>95%) of being in a state of high symbiotic persistence, meaning that they show a continued capacity to form the symbiosis over evolutionary time, even though the partnership has remained facultative and is not obligate. To explore patterns associated with the likelihood of loss and retention of the N2-fixing symbiosis, we tested for correlations between symbiotic persistence and legume distribution, climate, soil and trait data. We found a strong latitudinal effect and demonstrated that low mean annual temperatures are associated with high symbiotic persistence in legumes. Although no significant correlations between soil variables and symbiotic persistence were found, nitrogen and phosphorus leaf contents were positively correlated with legumes in a state of high symbiotic persistence. This pattern suggests that highly demanding nutrient lifestyles are associated with more stable partnerships, potentially because they “lock” the hosts into symbiotic dependency. Quantitative reconstruction methods are emerging as a powerful comparative tool to study broad patterns of symbiont loss and retention across diverse partnerships. PMID:26041807

  17. [Response of arbuscular mycorrhizal fungal lipid metabolism to symbiotic signals in mycorrhiza].

    PubMed

    Tian, Lei; Li, Yuanjing; Tian, Chunjie

    2016-01-01

    Arbuscular mycorrhizal (AM) fungi play an important role in energy flow and nutrient cycling, besides their wide distribution in the cosystem. With a long co-evolution, AM fungi and host plant have formed a symbiotic relationship, and fungal lipid metabolism may be the key point to find the symbiotic mechanism in arbusculart mycorrhiza. Here, we reviewed the most recent progress on the interaction between AM fungal lipid metabolism and symbiotic signaling networks, especially the response of AM fungal lipid metabolism to symbiotic signals. Furthermore, we discussed the response of AM fungal lipid storage and release to symbiotic or non-symbiotic status, and the correlation between fungal lipid metabolism and nutrient transfer in mycorrhiza. In addition, we explored the feedback of the lipolysis process to molecular signals during the establishment of symbiosis, and the corresponding material conversion and energy metabolism besides the crosstalk of fungal lipid metabolism and signaling networks. This review will help understand symbiotic mechanism of arbuscular mycorrhiza fungi and further application in ecosystem. PMID:27305777

  18. Evolutionary signals of symbiotic persistence in the legume-rhizobia mutualism.

    PubMed

    Werner, Gijsbert D A; Cornwell, William K; Cornelissen, Johannes H C; Kiers, E Toby

    2015-08-18

    Understanding the origins and evolutionary trajectories of symbiotic partnerships remains a major challenge. Why are some symbioses lost over evolutionary time whereas others become crucial for survival? Here, we use a quantitative trait reconstruction method to characterize different evolutionary stages in the ancient symbiosis between legumes (Fabaceae) and nitrogen-fixing bacteria, asking how labile is symbiosis across different host clades. We find that more than half of the 1,195 extant nodulating legumes analyzed have a high likelihood (>95%) of being in a state of high symbiotic persistence, meaning that they show a continued capacity to form the symbiosis over evolutionary time, even though the partnership has remained facultative and is not obligate. To explore patterns associated with the likelihood of loss and retention of the N2-fixing symbiosis, we tested for correlations between symbiotic persistence and legume distribution, climate, soil and trait data. We found a strong latitudinal effect and demonstrated that low mean annual temperatures are associated with high symbiotic persistence in legumes. Although no significant correlations between soil variables and symbiotic persistence were found, nitrogen and phosphorus leaf contents were positively correlated with legumes in a state of high symbiotic persistence. This pattern suggests that highly demanding nutrient lifestyles are associated with more stable partnerships, potentially because they "lock" the hosts into symbiotic dependency. Quantitative reconstruction methods are emerging as a powerful comparative tool to study broad patterns of symbiont loss and retention across diverse partnerships. PMID:26041807

  19. Cryptanalysis and improvement of an improved two factor authentication protocol for telecare medical information systems.

    PubMed

    Chaudhry, Shehzad Ashraf; Naqvi, Husnain; Shon, Taeshik; Sher, Muhammad; Farash, Mohammad Sabzinejad

    2015-06-01

    Telecare medical information systems (TMIS) provides rapid and convenient health care services remotely. Efficient authentication is a prerequisite to guarantee the security and privacy of patients in TMIS. Authentication is used to verify the legality of the patients and TMIS server during remote access. Very recently Islam et al. (J. Med. Syst. 38(10):135, 2014) proposed a two factor authentication protocol for TMIS using elliptic curve cryptography (ECC) to improve Xu et al.'s (J. Med. Syst. 38(1):9994, 2014) protocol. They claimed their improved protocol to be efficient and provides all security requirements. However our analysis reveals that Islam et al.'s protocol suffers from user impersonation and server impersonation attacks. Furthermore we proposed an enhanced protocol. The proposed protocol while delivering all the virtues of Islam et al.'s protocol resists all known attacks. PMID:25912427

  20. The Genetics of Symbiotic Nitrogen Fixation: Comparative Genomics of 14 Rhizobia Strains by Resolution of Protein Clusters

    PubMed Central

    Black, Michael; Moolhuijzen, Paula; Chapman, Brett; Barrero, Roberto; Howieson, John; Hungria, Mariangela; Bellgard, Matthew

    2012-01-01

    The symbiotic relationship between legumes and nitrogen fixing bacteria is critical for agriculture, as it may have profound impacts on lowering costs for farmers, on land sustainability, on soil quality, and on mitigation of greenhouse gas emissions. However, despite the importance of the symbioses to the global nitrogen cycling balance, very few rhizobial genomes have been sequenced so far, although there are some ongoing efforts in sequencing elite strains. In this study, the genomes of fourteen selected strains of the order Rhizobiales, all previously fully sequenced and annotated, were compared to assess differences between the strains and to investigate the feasibility of defining a core ‘symbiome’—the essential genes required by all rhizobia for nodulation and nitrogen fixation. Comparison of these whole genomes has revealed valuable information, such as several events of lateral gene transfer, particularly in the symbiotic plasmids and genomic islands that have contributed to a better understanding of the evolution of contrasting symbioses. Unique genes were also identified, as well as omissions of symbiotic genes that were expected to be found. Protein comparisons have also allowed the identification of a variety of similarities and differences in several groups of genes, including those involved in nodulation, nitrogen fixation, production of exopolysaccharides, Type I to Type VI secretion systems, among others, and identifying some key genes that could be related to host specificity and/or a better saprophytic ability. However, while several significant differences in the type and number of proteins were observed, the evidence presented suggests no simple core symbiome exists. A more abstract systems biology concept of nitrogen fixing symbiosis may be required. The results have also highlighted that comparative genomics represents a valuable tool for capturing specificities and generalities of each genome. PMID:24704847

  1. Fisher Pierce products for improving distribution system reliability

    SciTech Connect

    1994-12-31

    The challenges facing the electric power utility today in the 1990s has changed significantly from those of even 10 years ago. The proliferation of automation and the personnel computer have heightened the requirements and demands put on the electric distribution system. Today`s customers, fighting to compete in a world market, demand quality, uninterrupted power service. Privatization and the concept of unregulated competition require utilities to streamline to minimize system support costs and optimize power delivery efficiency. Fisher Pierce, serving the electric utility industry for over 50 years, offers a line of products to assist utilities in meeting these challenges. The Fisher Pierce Family of products provide tools for the electric utility to exceed customer service demands. A full line of fault indicating devices are offered to expedite system power restoration both locally and in conjunction with SCADA systems. Fisher Pierce is the largest supplier of roadway lighting controls, manufacturing on a 6 million dollar automated line assuring the highest quality in the world. The distribution system capacitor control line offers intelligent local or radio linked switching control to maintain system voltage and Var levels for quality and cost efficient power delivery under varying customer loads. Additional products, designed to authenticate revenue metering calibration and verify on sight metering service wiring, help optimize the profitability of the utility assuring continuous system service improvements for their customers.

  2. Advanced Technologies to Improve Closure of Life Support Systems

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.

    2016-01-01

    As NASA looks beyond the International Space Station toward long-duration, deep space missions away from Earth, the current practice of supplying consumables and spares will not be practical nor affordable. New approaches are sought for life support and habitation systems that will reduce dependency on Earth and increase mission sustainability. To reduce launch mass, further closure of Environmental Control and Life Support Systems (ECLSS) beyond the current capability of the ISS will be required. Areas of particular interest include achieving higher degrees of recycling within Atmosphere Revitalization, Water Recovery and Waste Management Systems. NASA is currently investigating advanced carbon dioxide reduction processes that surpass the level of oxygen recovery available from the Sabatier Carbon Dioxide Reduction Assembly (CRA) on the ISS. Candidate technologies will potentially improve the recovery of oxygen from about 50% (for the CRA) to as much as 100% for technologies who's end product is solid carbon. Improving the efficiency of water recycling and recovery can be achieved by the addition of advanced technologies to recover water from brines and solid wastes. Bioregenerative technologies may be utilized for water reclaimation and also for the production of food. Use of higher plants will simultaneously benefit atmosphere revitalization and water recovery through photosynthesis and transpiration. The level at which bioregenerative technologies are utilized will depend on their comparative requirements for spacecraft resources including mass, power, volume, heat rejection, crew time and reliability. Planetary protection requirements will need to be considered for missions to other solar system bodies.

  3. Improvements of wind noise reduction systems in the International Monitoring System infrasound network

    NASA Astrophysics Data System (ADS)

    Kramer, Alfred Christian; Marty, Julien

    2015-04-01

    The objective of this poster is to present the efforts made by the PTS over the last four years to assess and improve the robustness and efficiency of wind noise reduction systems. This work includes the improvement of the design of the pipe arrays by modelling the frequency response of the different types of filtering systems used within the IMS (International Monitoring System) infrasound network. It also includes the investigation and testing of new acoustic filtering system materials / components to improve the robustness of the pipe arrays. Efforts were also put into the improvement of pipe array design in order to enhance their flexibility to adapt to the station environmental conditions. Finally wind noise reduction system design was also enhanced to reduce maintenance activities and costs, as well as to extend their life cycle.

  4. Effects of subliminal symbiotic stimuli on anxiety reduction.

    PubMed

    Malik, R; Krasney, M S; Aldworth, B; Ladd, H W

    1996-06-01

    The present study assessed the effectiveness of subliminal psychodynamic stimuli in reducing anxiety. 50 male and 50 female college students were tachistoscopically exposed to one of five stimuli: MOMMY AND I ARE ONE, DADDY AND I ARE ONE, I AM HAPPY WITH MYSELF, ONE, or a control stimulus MYMMO NAD I REA ENO. It was hypothesized that men would show a significant decrease in anxiety to the MOMMY stimulus, while women were expected to respond favorably to either the MOMMY or DADDY stimulus, or to both. Results showed that the subliminal stimuli did not produce differential effects on anxiety. This finding did not support previous claims for subliminal psychodynamic activation that the stimulation of symbiotic fantasy with the maternal figure produces positive behavioral effects. Despite this negative finding women's response to the MOMMY message was predicted by measures of self-perception. PMID:8774013

  5. The 1984 eclipse of the symbiotic binary SY Muscae

    NASA Technical Reports Server (NTRS)

    Kenyon, S. J.; Michalitisianos, A. G.; Lutz, J. H.; Kafatos, M.

    1985-01-01

    Data from IUE spectra obtained with the 10 x 20-arcsec aperture on May 13, 1984, and optical spectrophotometry obtained with an SIT vidicon on the 1.5-m telescope at CTIO on April 29-May 1, 1984, are reported for the symbiotic binary SY Mus. The data are found to be consistent with a model of a red-giant secondary of 60 solar radii which completely eclipses the hot primary every 627 d but only partially eclipses the 75-solar-radius He(+) region surrounding the primary. The distance to SY Mus is estimated as 1.3 kpc. It is suggested that the large Balmer decrement in eclipse, with (H-alpha)/(H-beta) = 8.3 and (H-beta)/(H-gamma) = 1.5, is associated with an electron density of about 10 to the 10th/cu cm.

  6. [Mechanisms of the Effects of Probiotics on Symbiotic Digestion].

    PubMed

    Usakova, N A; Nekrasov, R V; Pravdin, I V; Sverchkova, N V; Kolomiyets, E I; Pavlov, D S

    2015-01-01

    The published data and our own data on the mechanisms of the influence of microbial probiotics, prebiotics, and their combinations on the processes of symbiotic digestion have been considered and generalized. It is shown that the effects on an organism are associated with the enhanced metabolic activity of intestinal bacteria: stimulation of bacterial fermentation of carbohydrates and formation of short-chained fatty acids, an increase in the blotting capacity of the intestines due to elongation of villi and deepening of crypts, and a decrease in secretion of toxic proteolytic products (ammonia, phenols, thiols, indoles, etc.). It has been shown that a combination of probiotics and prebiotic enhances the biological efficiency of a complex preparation, which contributes to activation of carbohydrate, protein, and mineral metabolism. PMID:26638234

  7. Spectroscopic observations of the symbiotic binary RW Hydrae

    NASA Technical Reports Server (NTRS)

    Kenyon, Scott J.; Fernandez-Castro, Telmo

    1987-01-01

    Ultraviolet/optical spectrophotometry and infrared photometry show that the symbiotic binary RW Hya is comprised of an M giant (with L of about 1000 solar luminosities) and a compact object (with L of about 200 solar luminosities) which resembles the central star of a planetary nebula. The luminosity of the hot component is produced by a nuclear shell source which is replenished by the wind of the red giant at a rate of about 10 to the -8th solar mass/yr. Results indicate that the binary is surrounded by an H II region (of radius of about 10 AU) which gives rise to the observed emission lines and radio emission. The He(2+) and O(2+) regions are found to be confined to the immediate vicinity of the hot component.

  8. The symbiotic star TX CVn has entered an active state

    NASA Astrophysics Data System (ADS)

    Munari, U.; Castellani, F.; Valisa, P.; Dallaporta, S.; Cherini, G.; Vagnozzi, A.; Righetti, G. L.; Belligoli, R.

    2014-01-01

    After the last active phase that begun in 2003, the symbiotic star TX CVn has now entered a new active phase. In 2003, TX CVn rose to B=10.5 and there it remained until the end of 2007 (Skopal 2007, AN 328, 909), when we started monitoring the variable with various ANS Collaboration telescopes in BVRI bands. Our observations show that the star has spent the following 6 years on a steady decline at a rate of 0.084 mag per year in the B band, that took it from B=10.55 on December 2007 to B=11.02 on September 2013, when the star begun a rapid brightening, reaching B=10.65 by early December 2013.

  9. H I spectrum of the symbiotic nova HM Sge

    SciTech Connect

    Leahy, D.A.; Taylor, A.R.; Young, G. )

    1990-06-01

    VLA observations are used to measure the H I spectrum of the symbiotic nova HM Sge. It is found that the H I column density to HM Sge is 4 x 10 to the 20th/sq cm and that the upper limit to the mass of circumstellar H I is 0.008 D-squared solar mass, with D equal to the distance to HM Sge in kparsecs. In addition, the spectrum of the quasar O V + 168 is used to show that the total Galactic H I column density in the direction of HM Sge is 9.5 x 10 to the 20th/sq cm. The implications of these results on the interpretation of other observations of HM Sge are discussed. 18 refs.

  10. An improved optical identity authentication system with significant output images

    NASA Astrophysics Data System (ADS)

    Yuan, Sheng; Liu, Ming-tang; Yao, Shu-xia; Xin, Yan-hui

    2012-06-01

    An improved method for optical identity authentication system with significant output images is proposed. In this method, a predefined image is digitally encoded into two phase-masks relating to a fixed phase-mask, and this fixed phase-mask acts as a lock to the system. When the two phase-masks, serving as the key, are presented to the system, the predefined image is generated at the output. In addition to simple verification, our method is capable of identifying the type of input phase-mask, and the duties of identity verification and recognition are separated and, respectively, assigned to the amplitude and phase of the output image. Numerical simulation results show that our proposed method is feasible and the output image with better image quality can be obtained.

  11. Power system stability improvement with multivariable self-tuning control

    SciTech Connect

    Fan, J.Y.; Ortmeyer, T.H.; Mukundan, R. )

    1990-02-01

    A multivariable self-tuning adaptive control scheme is presented. This scheme is of a decentralized nature and is implemented locally for individual generating units. A discrete multivariable auto-regressive-moving-average model is developed to represent a generating unit. The recursive-least-squares (RLS) estimation algorithm with variable-forgetting factor and the generalized-minimum-variance control technique are utilized to synthesize the local controllers. A dynamic goal-point-generating model is introduced to provide varying goal point for the local controller which leads the subsystem output to its equilibrium gradually. Extensive simulations are performed on the IEEE 10-machine test system. The results show that the proposed multivariable adaptive control scheme is effective in damping the severe oscillations after large disturbances as well as improving the system dynamics under small oscillations and is better than the conventional PSS method. The controller demonstrates robustness and is compatible with the existing conventional controllers in multimachine systems.

  12. New-old hemoglobin-like proteins of symbiotic dinoflagellates

    PubMed Central

    Rosic, Nedeljka N; Leggat, William; Kaniewska, Paulina; Dove, Sophie; Hoegh-Guldberg, Ove

    2013-01-01

    Symbiotic dinoflagellates are unicellular photosynthetic algae that live in mutualistic symbioses with many marine organisms. Within the transcriptome of coral endosymbionts Symbiodinium sp. (type C3), we discovered the sequences of two novel and highly polymorphic hemoglobin-like genes and proposed their 3D protein structures. At the protein level, four isoforms shared between 87 and 97% sequence identity for Hb-1 and 78–99% for Hb-2, whereas between Hb-1 and Hb-2 proteins, only 15–21% sequence homology has been preserved. Phylogenetic analyses of the dinoflagellate encoding Hb sequences have revealed a separate evolutionary origin of the discovered globin genes and indicated the possibility of horizontal gene transfer. Transcriptional regulation of the Hb-like genes was studied in the reef-building coral Acropora aspera exposed to elevated temperatures (6–7°C above average sea temperature) over a 24-h period and a 72-h period, as well as to nutrient stress. Exposure to elevated temperatures resulted in an increased Hb-1 gene expression of 31% after 72 h only, whereas transcript abundance of the Hb-2 gene was enhanced by up to 59% by both 1-day and 3-day thermal stress conditions. Nutrient stress also increased gene expression of Hb-2 gene by 70%. Our findings describe the differential expression patterns of two novel Hb genes from symbiotic dinoflagellates and their polymorphic nature. Furthermore, the inducible nature of Hb-2 gene by both thermal and nutrient stressors indicates a prospective role of this form of hemoglobin in the initial coral–algal responses to changes in environmental conditions. This novel hemoglobin has potential use as a stress biomarker. PMID:23610627

  13. Enhanced Symbiotic Performance by Rhizobium tropici Glycogen Synthase Mutants

    PubMed Central

    Marroquí, Silvia; Zorreguieta, Angeles; Santamaría, Carmen; Temprano, Francisco; Soberón, Mario; Megías, Manuel; Downie, J. Allan

    2001-01-01

    We isolated a Tn5-induced Rhizobium tropici mutant that has enhanced capacity to oxidize N,N-dimethyl-p-phenylendiamine (DMPD) and therefore has enhanced respiration via cytochrome oxidase. The mutant had increased levels of the cytochromes c1 and CycM and a small increase in the amount of cytochrome aa3. In plant tests, the mutant increased the dry weight of Phaseolus vulgaris plants by 20 to 38% compared with the control strain, thus showing significantly enhanced symbiotic performance. The predicted product of the mutated gene is homologous to glycogen synthases from several bacteria, and the mutant lacked glycogen. The DNA sequence of the adjacent gene region revealed six genes predicted to encode products homologous to the following gene products from Escherichia coli: glycogen phosphorylase (glgP), glycogen branching enzyme (glgB), ADP glucose pyrophosphorylase (glgC), glycogen synthase (glgA), phosphoglucomutase (pgm), and glycogen debranching enzyme (glgX). All six genes are transcribed in the same direction, and analysis with lacZ gene fusions suggests that the first five genes are organized in one operon, although pgm appears to have an additional promoter; glgX is transcribed independently. Surprisingly, the glgA mutant had decreased levels of high-molecular-weight exopolysaccharide after growth on glucose, but levels were normal after growth on galactose. A deletion mutant was constructed in order to generate a nonpolar mutation in glgA. This mutant had a phenotype similar to that of the Tn5 mutant, indicating that the enhanced respiration and symbiotic nitrogen fixation and decreased exopolysaccharide were due to mutation of glgA and not to a polar effect on a downstream gene. PMID:11208782

  14. Non-symbiotic hemoglobins in the life of seeds.

    PubMed

    Matilla, Angel J; Rodríguez-Gacio, María del Carmen

    2013-03-01

    Non-symbiotic hemoglobins (nsHbs), ancestors of symbiotic-Hbs, are hexacoordinated dimeric proteins, for which the crystal structure is well described. According to the extent of hexacoordination, nsHbs are classified as belonging to class-1 (nsHbs1) or class-2 (nsHbs2). The nsHbs1 show weak hexacoordination, moderate rates of O(2)-binding, very small rates of O(2) dissociation, and a remarkably high affinity for O(2), all suggesting a function involving O(2) scavenging. In contrast, the nsHbs2 exhibit strong hexacoordination, low rates of O(2)-binding and moderately low O(2) dissociation and affinity, suggesting a sensing role for sustained low (μM) levels of O(2). The existence of spatial and specific expression of nsHbs1 suggests that nsHbs play tissue-specific rather than housekeeping functions. The permeation of O(2) into seeds is usually prevented during the desiccation phase and early imbibition, generating an internal hypoxic environment that leads to ATP limitation. During evolution, the seed has acquired mechanisms to prevent or reduce this hypoxic stress. The nsHbs1/NO cycle appear to be involved in modulating the redox state in the seed and in maintaining an active metabolism. Under O(2) deficit, NADH and NO are synthesized in the seed and nsHbs1 scavenges O(2), which is used to transform NO into NO(3)(-) with concomitant formation of Fe(3+)-nsHbs1. Expression of nsHbs1 is not detectable in dry viable seeds. However, in the seeds cross-talk occurs between nsHbs1 and NO during germination. This review considers the current status of our knowledge of seed nsHbs and considers key issues of further work to better understand their role in seed physiology. PMID:23286879

  15. Improvement of forecasting system with optimal interpolation focusing on korea

    NASA Astrophysics Data System (ADS)

    Kang, J.; Koo, Y. S.

    2014-12-01

    A system for forecasting future air quality can play an important role as part of an air quality management system working in concert with more traditional emissions-based approaches. However, there are still a lot of uncertainties in modeling atmospheric. Data assimilation makes use of observation in order to reduce the uncertainties. This paper presents experiments of PM10(particulate matter <10㎛ in diameter) data assimilation with the optimal interpolation method. In order to improve the performance of chemical transport models (CTM) models in predicting pollutant concentrations for PM10, data assimilation techniques can be used. Model (CMAQ : Community Multiscale Air Quality Model) to simulate and assimilate PM10 concentration over Korea peninsula. The observations are provided by AAQMS (Ambient Air Quality Monitoring Stations in Korea).Data assimilation techniques combine measurements of the pollutant concentrations with model results to obtain better estimates of the true concentration levels(unknown). The method is then applied in operational-forecast conditions. It is found that the assimilation of PM10 observations significantly improves the one-day forecast of PM10, whereas the improvement is non significant for the tow-day forecast. We focus on the horizontal and temporal impacts of the data assimilation. The strategy followed in this paper with the optimal interpolation could be useful for operational forecasts.

  16. The effect of acidity on the distribution and symbiotic efficiency of rhizobia in Lithuanian soils

    NASA Astrophysics Data System (ADS)

    Lapinskas, E. B.

    2007-04-01

    The distribution and symbiotic efficiency of nodule bacteria Rhizobium leguminosarum_bv. trifolii F., Sinorhizobium meliloti D., Rhizobium galegae L., and Rhizobium leguminosarum bv. viciae F. in Lithuanian soils as dependent on the soil acidity were studied in the long-term field, pot, and laboratory experiments. The critical and optimal pH values controlling the distribution of rhizobia and the symbiotic nitrogen fixation were determined for every bacterial species. The relationship was found between the soil pH and the nitrogen-fixing capacity of rhizobia. A positive effect of liming of acid soils in combination with inoculation of legumes on the efficiency of symbiotic nitrogen fixation was demonstrated.

  17. Thirty Years of Improving the NCEP Global Forecast System

    NASA Astrophysics Data System (ADS)

    White, G. H.; Manikin, G.; Yang, F.

    2014-12-01

    Current eight day forecasts by the NCEP Global Forecast System are as accurate as five day forecasts 30 years ago. This revolution in weather forecasting reflects increases in computer power, improvements in the assimilation of observations, especially satellite data, improvements in model physics, improvements in observations and international cooperation and competition. One important component has been and is the diagnosis, evaluation and reduction of systematic errors. The effect of proposed improvements in the GFS on systematic errors is one component of the thorough testing of such improvements by the Global Climate and Weather Modeling Branch. Examples of reductions in systematic errors in zonal mean temperatures and winds and other fields will be presented. One challenge in evaluating systematic errors is uncertainty in what reality is. Model initial states can be regarded as the best overall depiction of the atmosphere, but can be misleading in areas of few observations or for fields not well observed such as humidity or precipitation over the oceans. Verification of model physics is particularly difficult. The Environmental Modeling Center emphasizes the evaluation of systematic biases against observations. Recently EMC has placed greater emphasis on synoptic evaluation and on precipitation, 2-meter temperatures and dew points and 10 meter winds. A weekly EMC map discussion reviews the performance of many models over the United States and has helped diagnose and alleviate significant systematic errors in the GFS, including a near surface summertime evening cold wet bias over the eastern US and a multi-week period when the GFS persistently developed bogus tropical storms off Central America. The GFS exhibits a wet bias for light rain and a dry bias for moderate to heavy rain over the continental United States. Significant changes to the GFS are scheduled to be implemented in the fall of 2014. These include higher resolution, improved physics and

  18. Improving the efficiency of solar photovoltaic power system

    NASA Astrophysics Data System (ADS)

    Aribisala, Henry A.

    As the local and national clamor for foreign energy independent United States continues to grow unabated; renewable energy has been receiving increased focus and it's widely believed that it's not only the answer to ever increasing demand for energy in this country, but also the environmentally friendly means of meeting such demand. During the spring of 2010, I was involved with a 5KW solar power system design project; the project involved designing and building solar panels and associated accessories like the solar array mounts and Solar Inverter system. One of the key issues we ran into during the initial stage of the project was how to select efficient solar cells for panel building at a reasonable cost. While we were able to purchase good solar cells within our allocated budget, the issue of design for efficiency was not fully understood , not just in the contest of solar cells performance , but also in the overall system efficiency of the whole solar power system, hence the door was opened for this thesis. My thesis explored and expanded beyond the scope of the aforementioned project to research different avenues for improving the efficiency of solar photo-voltaic power system from the solar cell level to the solar array mounting, array tracking and DC-AC inversion system techniques.

  19. Improvements and Extensions for Joint Polar Satellite System Algorithms

    NASA Astrophysics Data System (ADS)

    Grant, K. D.; Feeley, J. H.; Miller, S. W.; Jamilkowski, M. L.

    2014-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). JPSS replaced the afternoon orbit component and ground processing system of the old POES system managed by the NOAA. JPSS satellites will carry sensors designed to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground processing system for the JPSS is the Common Ground System (CGS), and provides command, control, and communications (C3), data processing and product delivery. CGS's data processing capability processes the data from the JPSS satellites to provide environmental data products (including Sensor Data Records (SDRs) and Environmental Data Records (EDRs)) to the NOAA Satellite Operations Facility. The first satellite in the JPSS constellation, known as the Suomi National Polar-orbiting Partnership (S-NPP) satellite, was launched on 28 October 2011. CGS is currently processing and delivering SDRs and EDRs for S-NPP and will continue through the lifetime of the JPSS program. The EDRs for S-NPP are currently undergoing an extensive Calibration and Validation (Cal/Val) campaign. Changes identified by the Cal/Val campaign are coming available for implementation into the operational system in support of both S-NPP and JPSS-1 (scheduled for launch in 2017). Some of these changes will be available in time to update the S-NPP algorithm baseline, while others will become operational just prior to JPSS-1 launch. In addition, new capabilities, such as higher spectral and spatial resolution, will be exercised on JPSS-1. This paper will describe changes to current algorithms and products as a result of the Cal/Val campaign and related initiatives for improved capabilities. Improvements include Cross Track Infrared Sounder high spectral

  20. When systems fail: improving care through technology can create risk.

    PubMed

    Bagalio, Sharon A

    2007-01-01

    Emerging medical technology is transforming the care of the modern-day patient. Hospital performance and patient safety is improving, lowering professional liability and medical malpractice costs. This advanced technology affects not only diagnosis and treatment but also hospital productivity and revenue. However, it also exposes hospitals and medical personnel to a number of unforeseeable risks. This article examines ongoing efforts to improve patient safety through the use of technology, automation and complex systems operations. It discusses the importance of skilled negotiation when vying for technology contracts and the value of maintaining a reliable data center to support it. Technology risk exposure is now a reality. A hospital needs to know how to protect itself from cyber liability, business interruption, and data loss and theft by ensuring that there is adequate coverage. PMID:20200890

  1. Improving systems documentation using an online copy editor

    SciTech Connect

    Kahn, R.L.

    1985-01-01

    For the last three years the author has been using Writers Workbench, a UNIX text-editing tool, to edit computer documentation. In this article the author outlines his experiences using the system, noting both the advantages to explore and pitfalls to avoid in using this tool. Writers Workbench is especially useful for improving a writer's basic skills - punctuation, spelling, and grammar. When used effectively, Writers Workbench can cut down on wordiness and improve the consistency of a manual. It can help in the creation of a table of contents, index, glossary, and bibliography and in checking readability. Furthermore, by creating user-defined dictionaries, authors or editors can customize the tool to fit their purposes and styles. However, Writers Workbench is not good at catching problems relating to organization, focus, and clarity.

  2. Improved low NOx firing systems for pulverized coal combustion

    SciTech Connect

    McCarthy, K.; Laux, S.; Grusha, J.; Rosin, T.; Hausman, G.L.

    1999-07-01

    More stringent emission limits or the addition of post combustion NOx control create the need for improvements of NOx emissions from pulverized coal boilers. Many boilers retrofitted with Low NOx technology during Phase 1 and Phase 2 of the CAAA fail or marginally meet their requirements. Technical solutions range from addition of overfire air and state-of-the-art low NOx burners to low cost additions of combustion enhancements. Regardless of the combustion NOx control method used, stoichiometries local to the burners must be maintained at the designed values at all times to provide high NOx performance at low efficiency loss due to unburned fuel. This paper describes Foster Wheeler's approach to NOx emission improvements for existing low NOx firing systems. The technology to measure air and coal flow individually for each burner and to control the parameters for optimum combustion are presented and discussed. Field experience shows the installation and advantages of the technology.

  3. Laboratory system strengthening and quality improvement in Ethiopia

    PubMed Central

    Hiwotu, Tilahun M.; Ayana, Gonfa; Mulugeta, Achamyeleh; Kassa, Getachew B.; Kebede, Yenew; Fonjungo, Peter N.; Tibesso, Gudeta; Desale, Adino; Kebede, Adisu; Kassa, Wondwossen; Mekonnen, Tesfaye; Yao, Katy; Luman, Elizabeth T.; Kebede, Amha; Linde, Mary K.

    2015-01-01

    Background In 2010, a National Laboratory Strategic Plan was set forth in Ethiopia to strengthen laboratory quality systems and set the stage for laboratory accreditation. As a result, the Strengthening Laboratory Management Toward Accreditation (SLMTA) programme was initiated in 45 Ethiopian laboratories. Objectives This article discusses the implementation of the programme, the findings from the evaluation process and key challenges. Methods The 45 laboratories were divided into two consecutive cohorts and staff from each laboratory participated in SLMTA training and improvement projects. The average amount of supportive supervision conducted in the laboratories was 68 hours for cohort I and two hours for cohort II. Baseline and exit audits were conducted in 44 of the laboratories and percent compliance was determined using a checklist with scores divided into zero- to five-star rating levels. Results Improvements, ranging from < 1 to 51 percentage points, were noted in 42 laboratories, whilst decreases were recorded in two. The average scores at the baseline and exit audits were 40% and 58% for cohort I (p < 0.01); and 42% and 53% for cohort II (p < 0.01), respectively. The p-value for difference between cohorts was 0.07. At the exit audit, 61% of the first and 48% of the second cohort laboratories achieved an increase in star rating. Poor awareness, lack of harmonisation with other facility activities and the absence of a quality manual were challenges identified. Conclusion Improvements resulting from SLMTA implementation are encouraging. Continuous advocacy at all levels of the health system is needed to ensure involvement of stakeholders and integration with other improvement initiatives and routine activities. PMID:26753129

  4. Systems of service: reflections on the moral foundations of improvement

    PubMed Central

    2011-01-01

    Providing clinical care is above all a service; in that sense, the medical profession aspires to Aristotelian phronesis, or prudence—being ‘capable of action with regard to things that are good and bad for man.’ This intense commitment to service encourages healthcare providers to gravitate towards one or another epistemology as their preferred moral pathway to better care. One such epistemology, the ‘snail’ perspective, places particular value on knowing whether newly devised clinical interventions are both effective and safe before applying them, mainly through rigorous experimental (deductive) studies, which contribute to the body of established scientific knowledge (episteme). Another (the ‘evangelist’ perspective) places particular value on the experiential learning gained from applying new clinical interventions, which contributes to professional know-how (techne). From the ‘snail’ point of view, implementing clinical interventions before their efficacy and safety are rigorously established is morally suspect because it can result in ineffective, wasteful and potentially harmful actions. Conversely, from the ‘evangelist’ point of view, demanding ‘hard’ proof of efficacy and safety before implementing every intervention is morally suspect because it can delay and obstruct the on-the-ground learning seen as being urgently needed to fix ineffective, inefficient and sometimes dangerous existing clinical practices. Two different moral syndromes—sets of interlocked values—underlie these perspectives; both are arguably essential for better care. Although it is not clear how best to leverage their combined strengths, a true symbiotic relationship between the two appears to be developing, one that leaves the two syndromes intact but softens their epistemological edges and supports active, close, respectful interaction between them. PMID:21450772

  5. Improvements in the CHERS system for DT experiments on TFTR

    SciTech Connect

    Bush, C.E.; Bell, R.; Synakowski, E.J.

    1995-03-01

    Improvements in the charge exchange recombination spectroscopy (CHERS) system have resulted in accurate measurements of T{sub i} and V{sub {phi}} profiles during DT experiments. These include moving the spectrometer detector array and electronics farther away from the tokamak to a low neutron flux location. This relocation has also improved access to all components of the system. Also, a nonplasma-viewing calibration fiber system was added to monitor the change in fiber transmission due to the high flux DT neutrons. Narrowband filtered light transmitted through the calibration fiber is now used as a reference for the VO measurement. At the highest neutron flux of {approximately} 2.5 {times} 10{sup 18} neutrons/see (fusion power {approximately} 6.2 MW) a modest 5% decrease in fiber transmission was observed. Corrections for transmission loss are made and T{sub i} (r,t) and absolute V{sub phi} (r,t) profiles are automatically calculated within four minutes of every shot.

  6. Improved Modeling in a Matlab-Based Navigation System

    NASA Technical Reports Server (NTRS)

    Deutschmann, Julie; Bar-Itzhack, Itzhack; Harman, Rick; Larimore, Wallace E.

    1999-01-01

    An innovative approach to autonomous navigation is available for low earth orbit satellites. The system is developed in Matlab and utilizes an Extended Kalman Filter (EKF) to estimate the attitude and trajectory based on spacecraft magnetometer and gyro data. Preliminary tests of the system with real spacecraft data from the Rossi X-Ray Timing Explorer Satellite (RXTE) indicate the existence of unmodeled errors in the magnetometer data. Incorporating into the EKF a statistical model that describes the colored component of the effective measurement of the magnetic field vector could improve the accuracy of the trajectory and attitude estimates and also improve the convergence time. This model is identified as a first order Markov process. With the addition of the model, the EKF attempts to identify the non-white components of the noise allowing for more accurate estimation of the original state vector, i.e. the orbital elements and the attitude. Working in Matlab allows for easy incorporation of new models into the EKF and the resulting navigation system is generic and can easily be applied to future missions resulting in an alternative in onboard or ground-based navigation.

  7. Applying Quality Improvement into Systems-based Learning to Improve Diabetes Outcomes in Primary Care.

    PubMed

    Moreo, Kathleen; Sapir, Tamar; Greene, Laurence

    2015-01-01

    In the U.S., where the prevalence of type 2 diabetes has reached epidemic proportions, many patients with this disease are treated by primary care physicians in community-based systems, including accountable care organisations (ACOs). To address gaps in the quality of diabetes care, national quality measures have been established, including patient-centered measures adopted by the Centers for Medicare and Medicaid Services for its Shared Savings Program for ACOs. From a patient-centered perspective, high-quality diabetes care depends on effective communication between clinicians and patients, along with patient education and counseling about medications and lifestyle. We designed and implemented a quality improvement (QI) program for 30 primary care physicians treating patients with type 2 diabetes in three structurally similar but geographically diverse ACOs. Retrospective chart audits were conducted before (n = 300) and after (n = 300) each physician participated in accredited continuing medical education (CME) courses that focused on QI strategies. Randomly selected charts were audited to measurably assess essential interventions for improved outcomes in type 2 diabetes including the physicians' documentation of patient counseling and assessment of side effects, and patients' medication adherence status and changes in hemoglobin A1C (A1C) and body mass index (BMI). Paced educational interventions included a private performance improvement Internet live course conducted for each physician, small-group Internet live courses involving peer discussion, and a set of enduring materials, which were also multi-accredited for all clinicians in the physician's practice. Continual improvement cycles were guided by analysis of the baseline chart audits, quantitative survey data, and qualitative feedback offered by participants. To extend the benefit of the education, the enduring materials were offered to the interprofessional team of clinicians throughout the U.S. who did

  8. Applying Quality Improvement into Systems-based Learning to Improve Diabetes Outcomes in Primary Care

    PubMed Central

    Moreo, Kathleen; Sapir, Tamar; Greene, Laurence

    2015-01-01

    In the U.S., where the prevalence of type 2 diabetes has reached epidemic proportions, many patients with this disease are treated by primary care physicians in community-based systems, including accountable care organisations (ACOs). To address gaps in the quality of diabetes care, national quality measures have been established, including patient-centered measures adopted by the Centers for Medicare and Medicaid Services for its Shared Savings Program for ACOs. From a patient-centered perspective, high-quality diabetes care depends on effective communication between clinicians and patients, along with patient education and counseling about medications and lifestyle. We designed and implemented a quality improvement (QI) program for 30 primary care physicians treating patients with type 2 diabetes in three structurally similar but geographically diverse ACOs. Retrospective chart audits were conducted before (n = 300) and after (n = 300) each physician participated in accredited continuing medical education (CME) courses that focused on QI strategies. Randomly selected charts were audited to measurably assess essential interventions for improved outcomes in type 2 diabetes including the physicians’ documentation of patient counseling and assessment of side effects, and patients’ medication adherence status and changes in hemoglobin A1C (A1C) and body mass index (BMI). Paced educational interventions included a private performance improvement Internet live course conducted for each physician, small-group Internet live courses involving peer discussion, and a set of enduring materials, which were also multi-accredited for all clinicians in the physician's practice. Continual improvement cycles were guided by analysis of the baseline chart audits, quantitative survey data, and qualitative feedback offered by participants. To extend the benefit of the education, the enduring materials were offered to the interprofessional team of clinicians throughout the U.S. who

  9. CONSTRUCTED WETLAND TREATMENT SYSTEMS FOR WATER QUALITY IMPROVEMENT

    SciTech Connect

    Nelson, E.

    2010-07-19

    The Savannah River National Laboratory implemented a constructed wetland treatment system (CWTS) in 2000 to treat industrial discharge and stormwater from the Laboratory area. The industrial discharge volume is 3,030 m{sup 3} per day with elevated toxicity and metals (copper, zinc and mercury). The CWTS was identified as the best treatment option based on performance, capital and continuing cost, and schedule. A key factor for this natural system approach was the long-term binding capacity of heavy metals (especially copper, lead, and zinc) in the organic matter and sediments. The design required that the wetland treat the average daily discharge volume and be able to handle 83,280 m{sup 3} of stormwater runoff in a 24 hour period. The design allowed all water flow within the system to be driven entirely by gravity. The CWTS for A-01 outfall is composed of eight one-acre wetland cells connected in pairs and planted with giant bulrush to provide continuous organic matter input to the system. The retention basin was designed to hold stormwater flow and to allow controlled discharge to the wetland. The system became operational in October of 2000 and is the first wetland treatment system permitted by South Carolina DHEC for removal of metals. Because of the exceptional performance of the A-01 CWTS, the same strategy was used to improve water quality of the H-02 outfall that receives discharge and stormwater from the Tritium Area of SRS. The primary contaminants in this outfall were also copper and zinc. The design for this second system required that the wetland treat the average discharge volume of 415 m{sup 3} per day, and be able to handle 9,690 m{sup 3} of stormwater runoff in a 24 hour period. This allowed the building of a system much smaller than the A-01 CWTS. The system became operational in July 2007. Metal removal has been excellent since water flow through the treatment systems began, and performance improved with the maturation of the vegetation during

  10. Lead/acid batteries in systems to improve power quality

    NASA Astrophysics Data System (ADS)

    Taylor, P.; Butler, P.; Nerbun, W.

    Increasing dependence on computer technology is driving needs for extremely high-quality power to prevent loss of information, material, and workers' time that represent billions of dollars annually. This cost has motivated commercial and Federal research and development of energy storage systems that detect and respond to power-quality failures in milliseconds. Electrochemical batteries are among the storage media under investigation for these systems. Battery energy storage systems that employ either flooded lead/acid or valve-regulated lead/acid battery technologies are becoming commercially available to capture a share of this emerging market. Cooperative research and development between the US Department of Energy and private industry have led to installations of lead/acid-based battery energy storage systems to improve power quality at utility and industrial sites and commercial development of fully integrated, modular battery energy storage system products for power quality. One such system by AC Battery Corporation, called the PQ2000, is installed at a test site at Pacific Gas and Electric Company (San Ramon, CA, USA) and at a customer site at Oglethorpe Power Corporation (Tucker, GA, USA). The PQ2000 employs off-the-shelf power electronics in an integrated methodology to control the factors that affect the performance and service life of production-model, low-maintenance, flooded lead/acid batteries. This system, and other members of this first generation of lead/acid-based energy storage systems, will need to compete vigorously for a share of an expanding, yet very aggressive, power quality market.

  11. Improved Peak Cancellation for PAPR Reduction in OFDM Systems

    NASA Astrophysics Data System (ADS)

    Dan, Lilin; Xiao, Yue; Ni, Wei; Li, Shaoqian

    This letter presents an improved peak cancellation (PC) scheme for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems. The main idea is based on a serial peak cancellation (SPC) mode for alleviating the peak regrowth of the conventional schemes. Based on the SPC mode, two particular algorithms are developed with different tradeoff between PAPR and computational complexity. Simulation shows that the proposed scheme has a better tradeoff among PAPR, complexity and signal distortion than the conventional schemes.

  12. Integrated Self-Management System for Improved Treatment of Asthma

    PubMed Central

    NGUYEN, Kristen T.; CULJAT, Martin O.; MIERZWA, Andrzej P.; SINGH, Rahul S.; FONG, Benson; VANLANDINGHAM, Rebecca

    2016-01-01

    A mobile, affordable product that provides clinicians and patients with comprehensive asthma assessment is needed to improve asthma control. Our solution is an integrated system consisting of a portable, inexpensive, easy-to-use spirometer and a mobile application that communicates wirelessly with the spirometer. Results demonstrated that the wireless asthma management solution meets recommended American Thoracic Society (ATS) and European Respiratory Society (ERS) standards. The device is expected to empower patients to accurately self-assess their asthma for better self-management at home, work, or leisure. PMID:27046589

  13. An Improved Platform Levelling System for Airborne Gravity Meters.

    NASA Astrophysics Data System (ADS)

    Brady, N.

    2014-12-01

    Recent advances in sensor technology have enabled Lacoste and Romberg type relative gravity meters to improve in accuracy to the point where other non-sensor related sources of error serve to limit the overall accuracy of the system. One of these sources of error is derived from the inability of the platform, in which the sensor is mounted, to keep the sensor perfectly level during survey flight. Off level errors occur when the aircraft is unable to maintain straight and level flight along a survey line. The levelling platform of a typical Lacoste and Romberg type dynamic gravity meter utilizes a complex feedback loop involving both accelerometers and gyroscopes with an output connected to torque motors mounted to the platform to sense an off level situation and correct for it. The current system is limited by an inability of the platform to distinguish between an acceleration of the platform due to a change in heading, altitude or speed of the aircraft and a true change in the local gravity vertical. Both of these situations cause the platform to tilt in reponse however the aircraft acceleration creates an error in the gravity measurement. These off level errors can be corrected for to a limited degree depending on the algorithm used and the size and duration of the causal acceleration. High precision GPS now provides accurate real time position information which can be used to determine if an accleration is a real level change or due to an anomalous acceleration. The correct implementation of the GPS position can significantly improve the accuracy of the platform levelling including keeping the platform level during course reversals or drape flying during a survey. This can typically improve the quality of the gravity data before any processing corrections. The enhanced platform also reduces the time taken to stabilize the platform at the beginning of a survey line therefore improving the efficiency of the data collection. This paper discusses the method and

  14. Improving the security of optoelectronic delayed feedback system by parameter modulation and system coupling

    NASA Astrophysics Data System (ADS)

    Liu, Lingfeng; Miao, Suoxia; Cheng, Mengfan; Gao, Xiaojing

    2016-02-01

    A coupled system with varying parameters is proposed to improve the security of optoelectronic delayed feedback system. This system is coupled by two parameter-varied optoelectronic delayed feedback systems with chaotic modulation. Dynamics performance results show that this system has a higher complexity compared to the original one. Furthermore, this system can conceal the time delay effectively against the autocorrelation function and delayed mutual information method and can increase the dimension space of secure parameters to resist brute-force attack by introducing the digital chaotic systems.

  15. The Improved Dual-view Field Goniometer System FIGOS

    PubMed Central

    Schopfer, Jürg; Dangel, Stefan; Kneubühler, Mathias; Itten, Klaus I.

    2008-01-01

    In spectrodirectional Remote Sensing (RS) the Earth's surface reflectance characteristics are studied by means of their angular dimensions. Almost all natural surfaces exhibit an individual anisotropic reflectance behaviour due to the contrast between the optical properties of surface elements and background and the geometric surface properties of the observed scene. The underlying concept, which describes the reflectance characteristic of a specific surface area, is called the bidirectional reflectance distribution function (BRDF). BRDF knowledge is essential for both correction of directional effects in RS data and quantitative retrieval of surface parameters. Ground-based spectrodirectional measurements are usually performed with goniometer systems. An accurate retrieval of the bidirectional reflectance factors (BRF) from field goniometer measurements requires hyperspectral knowledge of the angular distribution of the reflected and the incident radiation. However, prior to the study at hand, no operational goniometer system was able to fulfill this requirement. This study presents the first dual-view field goniometer system, which is able to simultaneously collect both the reflected and the incident radiation at high angular and spectral resolution and, thus, providing the necessary spectrodirectional datasets to accurately retrieve the surface specific BRF. Furthermore, the angular distribution of the incoming diffuse radiation is characterized for various atmospheric conditions and the BRF retrieval is performed for an artificial target and compared to laboratory spectrodirectional measurement results obtained with the same goniometer system. Suggestions for further improving goniometer systems are given and the need for intercalibration of various goniometers as well as for standardizing spectrodirectional measurements is expressed.

  16. Analysis of the Peroxidase Activity of Rice (Oryza Sativa) Recombinant Hemoglobin 1: Implications for the In Vivo Function of Hexacoordinate Non-Symbiotic Hemoglobins in Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In plants, it has been proposed that hexacoordinate (class 1) non-symbiotic Hbs (nsHb-1) function in vivo as peroxidases. However, little is known about the peroxidase activity of nsHb-1. We evaluated the peroxidase activity of rice recombinant Hb1 (a nsHb-1) by using the guaiacol/H2O2 system at pH ...

  17. Flight test of an improved solid waste collection system

    NASA Technical Reports Server (NTRS)

    Thornton, W.; Brasseaux, H.; Whitmore, H.

    1991-01-01

    A system for human waste collection is described and evaluated on the basis of a prototype employed for the shuttle flight STS-35. The manually operated version of the unit is designed to collect, compact, and store human waste and cleaning material in replaceable volumes. The system is presented with illustrations and descriptions of the disposable pads that are used to clean the cylinder and occlusive air valves as well as seal the unit. Temporary retention and waste entrainment are provided by the variable airflow in the manual unit tested. The prototype testing indicates that sufficient airflow is achieved at 45 CFM and that the stowage volume (18.7 cu in.) is adequate for storing human waste with minimal logistical support. Higher compaction pressure and the use of a directed airstream are proposed for improving the packing efficiency of the unit.

  18. How Can Health System Efficiency Be Improved in Canada?

    PubMed

    Allin, Sara; Veillard, Jeremy; Wang, Li; Grignon, Michel

    2015-08-01

    Improving value for money in the health system is an often-stated policy goal. This study is the first to systematically measure the efficiency of health regions in Canada in producing health gains with their available resources, and to identify the factors that are associated with increased efficiency. Based on the objective elicited from decision-makers that the health system should ensure access to care for Canadians when they need it, we measured the efficiency with which regions reduce causes of death that are amenable to healthcare interventions using a linear programming approach (data envelopment analysis). Variations in efficiency were explained in part by public health factors, such as the prevalence of obesity and smoking in the population; in part by characteristics of the population, such as their average income; and in part by managerial factors, such as hospital readmissions. PMID:26571467

  19. New software system to improve AGU membership management

    NASA Astrophysics Data System (ADS)

    McEntee, Chris

    2012-06-01

    Almost 2 years ago, AGU began investigating how it could more efficiently manage member and customer records as well as support processes that currently run on multiple systems. I am pleased to announce that on 25 June, as the result of intense efforts, AGU will migrate to a new database software system that will house the majority of AGU operations. AGU staff will have more tools at their disposal to assist members, and members will have more intuitive and user-friendly options when using the online interface to update their profiles or make purchases. I am particularly excited about this major improvement to our infrastructure because it better positions AGU to achieve goals in its strategic plan.

  20. Extended Duration Orbiter (EDO) Improved Waste Collection System (IWCS)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This high angle overall view shows the top side components of the Extended Duration Orbiter (EDO) Waste Collection System (WCS) scheduled to fly aboard NASA's Endeavour, Orbiter Vehicle (OV) 105, for the STS-54 mission. Detailed Test Objective 662, Extended duration orbiter WCS evaluation, will verify the design of the new EDO WCS under microgravity conditions for a prolonged period. OV-105 has been modified with additional structures in the waste management compartment (WMC) and additional avionics to support/restrain the EDO WCS. Among the advantages the new IWCS is hoped to have over the currect WCS are greater dependability, better hygiene, virtually unlimited capacity, and more efficient preparation between shuttle missions. Unlike the previous WCS, the improved version will not have to be removed from the spacecraft to be readied for the next flight. The WCS was documented in JSC's Crew Systems Laboratory Bldg 7.

  1. Extended Duration Orbiter (EDO) Improved Waste Collection System (IWCS)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This overall front view shows the Extended Duration Orbiter (EDO) Waste Collection System (WCS) scheduled to fly aboard NASA's Endeavour, Orbiter Vehicle (OV) 105, for the STS-54 mission. Detailed Test Objective 662, Extended duration orbiter WCS evaluation, will verify the design of the new EDO WCS under microgravity conditions for a prolonged period. OV-105 has been modified with additional structures in the waste management compartment (WMC) and additional avionics to support/restrain the EDO WCS. Among the advantages the new IWCS is hoped to have over the currect WCS are greater dependability, better hygiene, virtually unlimited capacity, and more efficient preparation between shuttle missions. Unlike the previous WCS, the improved version will not have to be removed from the spacecraft to be readied for the next flight. The WCS was documented in JSC's Crew Systems Laboratory Bldg 7.

  2. A new quality assessment and improvement system for print media

    NASA Astrophysics Data System (ADS)

    Liu, Mohan; Konya, Iuliu; Nandzik, Jan; Flores-Herr, Nicolas; Eickeler, Stefan; Ndjiki-Nya, Patrick

    2012-12-01

    Print media collections of considerable size are held by cultural heritage organizations and will soon be subject to digitization activities. However, technical content quality management in digitization workflows strongly relies on human monitoring. This heavy human intervention is cost intensive and time consuming, which makes automization mandatory. In this article, a new automatic quality assessment and improvement system is proposed. The digitized source image and color reference target are extracted from the raw digitized images by an automatic segmentation process. The target is evaluated by a reference-based algorithm. No-reference quality metrics are applied to the source image. Experimental results are provided to illustrate the performance of the proposed system. We show that it features a good performance in the extraction as well as in the quality assessment step compared to the state-of-the-art. The impact of efficient and dedicated quality assessors on the optimization step is extensively documented.

  3. Information systems as a tool to improve legal metrology activities

    NASA Astrophysics Data System (ADS)

    Rodrigues Filho, B. A.; Soratto, A. N. R.; Gonçalves, R. F.

    2016-07-01

    This study explores the importance of information systems applied to legal metrology as a tool to improve the control of measuring instruments used in trade. The information system implanted in Brazil has also helped to understand and appraise the control of the measurements due to the behavior of the errors and deviations of instruments used in trade, allowing the allocation of resources wisely, leading to a more effective planning and control on the legal metrology field. A study case analyzing the fuel sector is carried out in order to show the conformity of fuel dispersers according to maximum permissible errors. The statistics of measurement errors of 167,310 fuel dispensers of gasoline, ethanol and diesel used in the field were analyzed demonstrating the accordance of the fuel market in Brazil to the legal requirements.

  4. Improving Photometric Calibration of Meteor Video Camera Systems

    NASA Technical Reports Server (NTRS)

    Ehlert, Steven; Kingery, Aaron; Cooke, William

    2016-01-01

    Current optical observations of meteors are commonly limited by systematic uncertainties in photometric calibration at the level of approximately 0.5 mag or higher. Future improvements to meteor ablation models, luminous efficiency models, or emission spectra will hinge on new camera systems and techniques that significantly reduce calibration uncertainties and can reliably perform absolute photometric measurements of meteors. In this talk we discuss the algorithms and tests that NASA's Meteoroid Environment Office (MEO) has developed to better calibrate photometric measurements for the existing All-Sky and Wide-Field video camera networks as well as for a newly deployed four-camera system for measuring meteor colors in Johnson-Cousins BV RI filters. In particular we will emphasize how the MEO has been able to address two long-standing concerns with the traditional procedure, discussed in more detail below.

  5. Improving the representation of hydrologic processes in Earth System Models

    SciTech Connect

    Clark, Martyn P.; Fan, Ying; Lawrence, David M.; Adam, Jennifer C.; Bolster, Diogo; Gochis, David J.; Hooper, Richard P.; Kumar, Mukesh; Leung, L. Ruby; Mackay, D. Scott; Maxwell, Reed M.; Shen, Chaopeng; Swenson, Sean C.; Zeng, Xubin

    2015-08-21

    Many of the scientific and societal challenges in understanding and preparing for global environmental change rest upon our ability to understand and predict the water cycle change at large river basin, continent, and global scales. However, current large-scale models, such as the land components of Earth System Models (ESMs), do not yet represent the terrestrial water cycle in a fully integrated manner or resolve the finer-scale processes that can dominate large-scale water budgets. This paper reviews the current representation of hydrologic processes in ESMs and identifies the key opportunities for improvement. This review suggests that (1) the development of ESMs has not kept pace with modeling advances in hydrology, both through neglecting key processes (e.g., groundwater) and neglecting key aspects of spatial variability and hydrologic connectivity; and (2) many modeling advances in hydrology can readily be incorporated into ESMs and substantially improve predictions of the water cycle. Accelerating modeling advances in ESMs requires comprehensive hydrologic benchmarking activities, in order to systematically evaluate competing modeling alternatives, understand model weaknesses, and prioritize model development needs. This demands stronger collaboration, both through greater engagement of hydrologists in ESM development and through more detailed evaluation of ESM processes in research watersheds. Advances in the representation of hydrologic process in ESMs can substantially improve energy, carbon and nutrient cycle prediction capabilities through the fundamental role the water cycle plays in regulating these cycles.

  6. CLAES Product Improvement by use of GSFC Data Assimilation System

    NASA Technical Reports Server (NTRS)

    Kumer, J. B.; Douglass, Anne (Technical Monitor)

    2001-01-01

    Recent development in chemistry transport models (CTM) and in data assimilation systems (DAS) indicate impressive predictive capability for the movement of airparcels and the chemistry that goes on within these. This project was aimed at exploring the use of this capability to achieve improved retrieval of geophysical parameters from remote sensing data. The specific goal was to improve retrieval of the CLAES CH4 data obtained during the active north high latitude dynamics event of 18 to 25 February 1992. The model capabilities would be used: (1) rather than climatology to improve on the first guess and the a-priori fields, and (2) to provide horizontal gradients to include in the retrieval forward model. The retrieval would be implemented with the first forward DAS prediction. The results would feed back to the DAS and a second DAS prediction for first guess, a-priori and gradients would feed to the retrieval. The process would repeat to convergence and then proceed to the next day.

  7. Confirmation of the Symbiotic Nature of CXOGBS J173620.2-293338

    NASA Astrophysics Data System (ADS)

    Hynes, Robert

    2013-09-01

    The Galactic Bulge Survey (GBS) detected 1640 faint bulge X-ray sources. CX332 lies within 1" of an asymptotic giant branch carbon star. Bulge carbon stars are extremely rare, so we estimate only a 0.1% of chance coincidence within 1" with ANY GBS source, so it is likely to be a symbiotic. The X-ray hardness and optical spectrum suggest it might be neutron star symbiotic X-ray binary (SyXB). It would be only the second SyXB with a carbon star, and the first based on a secure X-ray detection. A deeper observation will i) obtain a precise, on-axis X-ray position to confirm or refute the positional assocation; ii) obtain an X-ray spectrum to classify the symbiotic type; iii) search for the large amplitude variability typical of symbiotics, and possibly measure a neutron star spin period.

  8. The Symbiotic Relationship of Science and Technology in the 21st Century.

    ERIC Educational Resources Information Center

    Wiens, A. Emerson

    1999-01-01

    There are many examples in which science and technology complement each other. This is especially evident in biotechnology and genetic engineering. This symbiotic relationship is foundational to the technological culture of contemporary society. (SK)

  9. Improvement of the AeroClipper system for cyclones monitoring

    NASA Astrophysics Data System (ADS)

    Vargas, André; Philippe, Duvel Jean

    2016-07-01

    The AeroClipper developed by the French space agency (Centre National d'Études Spatiales, CNES) is a quasi-lagrangian device drifting with surface wind at about 20-30m above the ocean surface. It is a new and original device for real-time and continuous observation of air-sea surface parameters in open ocean remote regions. This device enables the sampling of the variability of surface parameters in particular under convective systems toward which it is attracted. The AeroClipper is therefore an ideal instrument to monitor Tropical Cyclones (TCs) in which they are likely to converge and provide original observations to evaluate and improve our current understanding and diagnostics of TCs as well as their representation in numerical models. In 2008, the AeroClipper demonstrates its capability to be captured by an Ocean Indian cyclone, as two models have converged, without damages, in the eye of Dora cyclone during the 2008 VASCO campaign. This paper will present the improvements of this balloon system for the international project 'the Year of Maritime Continent'.

  10. An improved flapping wing system actuated by the LIPCA

    NASA Astrophysics Data System (ADS)

    Syaifuddin, Moh.; Park, Hoon C.; Lee, Sang K.; Byun, Do Y.

    2006-03-01

    This paper presents an improved version of the insect-mimicking flapping-wing mechanism actuated by LIPCA (Lightweight Piezo-Composite Actuator). As the previous version, the actuation displacement of the actuator is converted into flapping-wing motion by a mechanical linkage system that functioned as displacement amplifier as well. In order to provide feathering motion, the wing is attached to the axis through a hinge system that allows the wing rotation at each end of half-stroke, due to air resistance. In this improved version, the total weight has been reduced to the half of the previous one. The device could produce about 90 degree of flapping angle when it operated at around 10 Hz, which was the natural flapping-frequency. Several flapping tests under different parameter configurations were conducted in order to investigate the characteristic of the generated lift. In addition, the smoke-wire test was also conducted, so that the vortices around the wing can be visually observed. Even though the present wing has smaller wing area, it could produce higher lift then before.

  11. Improved power transfer to wearable systems through stretchable magnetic composites

    NASA Astrophysics Data System (ADS)

    Lazarus, N.; Bedair, S. S.

    2016-05-01

    The use of wireless power transfer is common in stretchable electronics since physical wiring can be easily destroyed as the system is stretched. This work presents the first demonstration of improved inductive power coupling to a stretchable system through the addition of a thin layer of ferroelastomeric material. A ferroelastomer, an elastomeric polymer loaded with magnetic particulates, has a permeability greater than one while retaining the ability to survive significant mechanical strains. A recently developed ferroelastomer composite based on sendust platelets within a soft silicone elastomer was incorporated into liquid metal stretchable inductors based on the liquid metal galinstan in fluidic channels. For a single-turn inductor, the maximum power transfer efficiency rises from 71 % with no backplane, to 81 % for a rigid ferrite backplane on the transmitter side alone, to 86 % with a ferroelastomer backplane on the receiver side as well. The coupling between a commercial wireless power transmitter coil with ferrite backplane to a five-turn liquid metal inductor was also investigated, finding an improvement in power transfer efficiency from 81 % with only a rigid backplane to 90 % with the addition of the ferroelastomer backplane. Both the single and multi-turn inductors were demonstrated surviving up to 50 % uniaxial applied strain.

  12. Submerged monoxenic culture medium development for Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus luminescens: protein sources.

    PubMed

    Cho, Chun-Hwi; Whang, Kyung Sook; Gaugler, Randy; Yoo, Sun Kyun

    2011-08-01

    Most medium formulations for improving culture of entomopathogenic nematodes (EPN) based on protein sources have used enriched media like animal feed such as dried egg yolk, lactalbumin, and liver extract, among other ingredients. Most results, however, showed unstable yields and longer production time. Many of the results do not show the detailed parameters of fermentation. Soy flour, cotton seed flour, corn gluten meal, casein powder, soytone, peptone, casein hydrolysates, and lactalbumin hydrolysate as protein sources were tested to determine the source to support optimal symbiotic bacteria and nematode growth. The protein hydrolysates selected did not improve bacterial cell mass compared with the yeast extract control, but soy flour was the best, showing 75.1% recovery and producing more bacterial cell number (1.4×10⁹/ml) than all other sources. The highest yield (1.85×10⁵ IJs/ml), yield coefficient (1.67×10⁶ IJs/g medium), and productivity (1.32×10⁷ IJs/l/day) were also achieved at enriched medium with soybean protein. PMID:21876379

  13. Improving the representation of photosynthesis in Earth system models

    NASA Astrophysics Data System (ADS)

    Rogers, A.; Medlyn, B. E.; Dukes, J.; Bonan, G. B.; von Caemmerer, S.; Dietze, M.; Kattge, J.; Leakey, A. D.; Mercado, L. M.; Niinemets, U.; Prentice, I. C. C.; Serbin, S.; Sitch, S.; Way, D. A.; Zaehle, S.

    2015-12-01

    Continued use of fossil fuel drives an accelerating increase in atmospheric CO2 concentration ([CO2]) and is the principal cause of global climate change. Many of the observed and projected impacts of rising [CO2] portend increasing environmental and economic risk, yet the uncertainty surrounding the projection of our future climate by Earth System Models (ESMs) is unacceptably high. Improving confidence in our estimation of future [CO2] is essential if we seek to project global change with greater confidence. There are critical uncertainties over the long term response of terrestrial CO2 uptake to global change, more specifically, over the size of the terrestrial carbon sink and over its sensitivity to rising [CO2] and temperature. Reducing the uncertainty associated with model representation of the largest CO2 flux on the planet is therefore an essential part of improving confidence in projections of global change. Here we have examined model representation of photosynthesis in seven process models including several global models that underlie the representation of photosynthesis in the land surface model component of ESMs that were part of the recent Fifth Assessment Report from the IPCC. Our approach was to focus on how physiological responses are represented by these models, and to better understand how structural and parametric differences drive variation in model responses to light, CO2, nutrients, temperature, vapor pressure deficit and soil moisture. We challenged each model to produce leaf and canopy responses to these factors to help us identify areas in which current process knowledge and emerging data sets could be used to improve model skill, and also identify knowledge gaps in current understanding that directly impact model outputs. We hope this work will provide a roadmap for the scientific activity that is necessary to advance process representation, parameterization and scaling of photosynthesis in the next generation of Earth System Models.

  14. Improvements to magnetic tracking system for virtual reality

    NASA Astrophysics Data System (ADS)

    Liu, Yue; Hu, Xiaoming; Wang, Yongtian; Yan, Dayuan

    2006-01-01

    Magnetic tracking system is widely used in a Virtual or Augmented Reality system to track the orientation and position of an object in space. When being applied in medical applications such as surgical navigation or medical image registration, accurate 6 DOF (Degree-of-Freedom) tracking is especially important. In order to compensate the influence of metal object and magnetic fields in the surrounding environments on the accuracy of the measurements, an AC magnetic tracking system whose orientation is obtained with the output of 3-axis orthogonal magnetic sensors and 2-axis accelerometers is designed. On the basis of analyzing the influence of environmental magnetic fields on the measurement accuracy of heading, a compensation algorithm is presented, which fits the outputs of the magnetic sensors to an ellipse with the principle of least square and rotation invariant and calibrates the heading with the parameters of the ellipse to rotate and scale the measurement results. Compared with the existing approach, the proposed method can effectively compensate the influence of environmental interference when the magnetic tracking system moves in horizontal plane and can also be applied in the applications with continuous movements. Experimental results show that the proposed method can effectively compensate environmental interference and improve the tracking accuracy.

  15. Three Replicons of Rhizobium sp. Strain NGR234 Harbor Symbiotic Gene Sequences

    PubMed Central

    Flores, Margarita; Mavingui, Patrick; Girard, Lourdes; Perret, Xavier; Broughton, William J.; Martínez-Romero, Esperanza; Dávila, Guillermo; Palacios, Rafael

    1998-01-01

    Rhizobium sp. strain NGR234 contains three replicons: the symbiotic plasmid or pNGR234a, a megaplasmid (pNGR234b), and the chromosome. Symbiotic gene sequences not present in pNGR234a were analyzed by hybridization. DNA sequences homologous to the genes fixLJKNOPQGHIS were found on the chromosome, while sequences homologous to nodPQ and exoBDFLK were found on pNGR234b. PMID:9811668

  16. Optical Manipulation of Symbiotic Chlorella in Paramecium Bursaria Using a Fiber Axicon Microlens

    NASA Astrophysics Data System (ADS)

    Taguchi, K.; Hirota, S.; Nakayama, H.; Kunugihara, D.; Mihara, Y.

    2012-03-01

    In this paper, chemically etched axicon fiber was proposed for laser trapping of symbiotic chlorella from paramecium bursaria. We fabricated axicon micro lenses on a single-mode bare optical fiber by selective chemical etching technique. The laser beam from fiber axicon microlens was strongly focused and optical forces were sufficient to move a symbiotic chlorella. From experimental results, it was found that our proposed fiber axicon microlens was a promising tool for cell trapping without physical contact.

  17. ESTs Analysis Reveals Putative Genes Involved in Symbiotic Seed Germination in Dendrobium officinale

    PubMed Central

    Zhao, Ming-Ming; Zhang, Gang; Zhang, Da-Wei; Hsiao, Yu-Yun; Guo, Shun-Xing

    2013-01-01

    Dendrobiumofficinale (Orchidaceae) is one of the world’s most endangered plants with great medicinal value. In nature, D. officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH) cDNA library of symbiotically germinated D. officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs) were clustered to 1074 Unigenes (including 902 singletons and 172 contigs), which were searched against the NCBI non-redundant (NR) protein database (E-value cutoff, e-5). Based on sequence similarity with known proteins, 579 differentially expressed genes in D. officinale were identified and classified into different functional categories by Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS). The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs), which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS), were cloned from D. officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D. officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids. PMID:23967335

  18. The Sinorhizobium meliloti ntrX Gene Is Involved in Succinoglycan Production, Motility, and Symbiotic Nodulation on Alfalfa

    PubMed Central

    Wang, Dong; Xue, Haiying; Wang, Yiwen; Yin, Ruochun; Xie, Fang

    2013-01-01

    Rhizobia establish a symbiotic relationship with their host legumes to induce the formation of nitrogen-fixing nodules. This process is regulated by many rhizobium regulators, including some two-component regulatory systems (TCSs). NtrY/NtrX, a TCS that was first identified in Azorhizobium caulinodans, is required for free-living nitrogen metabolism and symbiotic nodulation on Sesbania rostrata. However, its functions in a typical rhizobium such as Sinorhizobium meliloti remain unclear. Here we found that the S. meliloti response regulator NtrX but not the histidine kinase NtrY is involved in the regulation of exopolysaccharide production, motility, and symbiosis with alfalfa. A plasmid insertion mutant of ntrX formed mucous colonies, which overproduced succinoglycan, an exopolysaccharide, by upregulating its biosynthesis genes. This mutant also exhibited motility defects due to reduced flagella and decreased expression of flagellins and regulatory genes. The regulation is independent of the known regulatory systems of ExoR/ExoS/ChvI, EmmABC, and ExpR. Alfalfa plants inoculated with the ntrX mutant were small and displayed symptoms of nitrogen starvation. Interestingly, the deletion mutant of ntrY showed a phenotype similar to that of the parent strain. These findings demonstrate that the S. meliloti NtrX is a new regulator of succinoglycan production and motility that is not genetically coupled with NtrY. PMID:24038694

  19. OAK RIDGE NATIONAL LABORATORY SPALLATION NEUTRON SOURCE ELECTRICAL SYSTEMS AVAILABILITY AND IMPROVEMENTS

    SciTech Connect

    Cutler, Roy I; Peplov, Vladimir V; Wezensky, Mark W; Norris, Kevin Paul; Barnett, William E; Hicks, Jim; Weaver, Joey T; Moss, John; Rust, Kenneth R; Mize, Jeffery J; Anderson, David E

    2011-01-01

    SNS electrical systems have been operational for 4 years. System availability statistics and improvements are presented for AC electrical systems, DC and pulsed power supplies and klystron modulators.

  20. Validation of a decision support system for improving irrigation system performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To address water shortage and improve water delivery operations, decision support systems have been developed and utilized throughout the United States and the world. One critical aspect that is often neglected during the development and implementation of decision support systems is validation, whi...

  1. Comparability of the Social Skills Improvement System to the Social Skills Rating System: A Norwegian Study

    ERIC Educational Resources Information Center

    Gamst-Klaussen, Thor; Rasmussen, Lene-Mari P.; Svartdal, Frode; Strømgren, Børge

    2016-01-01

    The Social Skills Improvement System-Rating Scales (SSIS-RS) is a multi-informant instrument assessing social skills and problem behavior in children and adolescents. It is a revised version of the Social Skills Rating System (SSRS). A Norwegian translation of the SSRS has been validated, but this has not yet been done for the Norwegian…

  2. The effects of symbiotic therapy on anthropometric measures, body composition and blood pressure in patient with metabolic syndrome: a triple blind RCT

    PubMed Central

    Rabiei, Samira; Shakerhosseini, Rahebeh; Saadat, Navid

    2015-01-01

    Background: Increase in prevalence of obesity and type 2 diabetes which are of the main risk factors of metabolic syndrome, is not only the result of changes in genetic, diet or physical activity, but also an imbalance of micro flora may play an important role. Therefore, alteration of micro flora using pre/probiotic is considered as a new strategy for treatment of metabolic disorders. Methods: The current study is a triple blind randomized controlled trial. 46 patients from both sexes, who fulfilled inclusion criteria, randomly categorized into intervention or placebo group. The intervention and placebo groups consumed 2 probiotic capsules or 2 placebo capsules during 3 months, respectively. Both groups received a weight loss diet, according to their adjusted ideal body weight. Anthropometric, body composition, blood pressure and nutritional measurements were done in the beginning, at 6th week, and at the end of the study. T-test and paired-t test were used for statistical analysis. Results: 40 patients completed the study. BMI, WC, HC, fat mass, lean mass and blood pressure were reduced in all participants (p< 0.05). Systolic blood pressure in symbiotic group was less than placebo group, significantly (p< 0.05). The trend of weight loss in symbiotic group continued at least for 12 weeks while it was stopped at week 6 in placebo group. Conclusion: Symbiotic supplement with the weight loss diet had synergistic effects on improvement in systolic blood pressure and anthropometric measurements. Based on our findings, symbiotic can postpone plateau phase of weight loss and it may prevent resistance to further weight loss. PMID:26478871

  3. Exploration of the core metabolism of symbiotic bacteria

    PubMed Central

    2012-01-01

    Background A large number of genome-scale metabolic networks is now available for many organisms, mostly bacteria. Previous works on minimal gene sets, when analysing host-dependent bacteria, found small common sets of metabolic genes. When such analyses are restricted to bacteria with similar lifestyles, larger portions of metabolism are expected to be shared and their composition is worth investigating. Here we report a comparative analysis of the small molecule metabolism of symbiotic bacteria, exploring common and variable portions as well as the contribution of different lifestyle groups to the reduction of a common set of metabolic capabilities. Results We found no reaction shared by all the bacteria analysed. Disregarding those with the smallest genomes, we still do not find a reaction core, however we did find a core of biochemical capabilities. While obligate intracellular symbionts have no core of reactions within their group, extracellular and cell-associated symbionts do have a small core composed of disconnected fragments. In agreement with previous findings in Escherichia coli, their cores are enriched in biosynthetic processes whereas the variable metabolisms have similar ratios of biosynthetic and degradation reactions. Conversely, the variable metabolism of obligate intracellular symbionts is enriched in anabolism. Conclusion Even when removing the symbionts with the most reduced genomes, there is no core of reactions common to the analysed symbiotic bacteria. The main reason is the very high specialisation of obligate intracellular symbionts, however, host-dependence alone is not an explanation for such absence. The composition of the metabolism of cell-associated and extracellular bacteria shows that while they have similar needs in terms of the building blocks of their cells, they have to adapt to very distinct environments. On the other hand, in obligate intracellular bacteria, catabolism has largely disappeared, whereas synthetic routes appear

  4. Improved Emergency Egress Lighting System for the ISS

    NASA Technical Reports Server (NTRS)

    Eaton, Leslie L.; Barr, Don A.

    2005-01-01

    Emergency lights provide illumination in corridors, stairwells, ramps, escalators, aisles, and exit passageways during power failures. Safety and visibility are critical during a power outage. If emergency lights fail to operate properly, the building occupants can become disoriented. Four documents in a collection discuss different topics relating to a proposed improved emergency egress lighting system (EELS) for the International Space Station (ISS). While the present EELS is designed around rows of green-light-emitting diodes, the proposed system contains strips of electroluminescent tape using different colors for each egress path. The proposed EELS can be powered by the same battery currently used by the present EELS, but would require an inverter because electroluminescent devices require AC. Electroluminescent devices also require significantly less current and, depending on the color, would emit 3 to 8 times the light of the present EELS. In addition, they could operate for up to 75 hours (versus .20 minutes for the present system). The first document contains a one-page summary of the proposal and an evaluation of technical merit. The second document summarizes the motivation for, and the design of, the proposed EELS. The third document addresses relevant aspects of the measurement of spectral sensitivity and the psychophysics of perception of light. The fourth document presents additional background information and technical specifications for the electroluminescent tapes.

  5. A new demodulation method improving FM system interference immunity

    NASA Astrophysics Data System (ADS)

    Stojanovic, Z. D.; Dukic, M. L.; Stojanovic, I. S.

    1981-07-01

    A new algorithm for the process of demodulation is proposed on the basis of an investigation of interference into FM systems. The algorithm offers better immunity against the baseband interference noise than does the method using the conventional limiter-discriminator. Desired signal processing is carried out by the functional devices added to the conventional limiter-discriminator in such a way that this new demodulator can be optimized in the sense of the minimum baseband interference noise. It is pointed out that here the statistics of the wanted and interfering signals must be known. Several examples involving interference problems in FDM-FM radio-relay systems carrying multichannel telephone signals are discussed to illustrate the performance of the proposed demodulator. FDM-FM, PSK, or FSK systems are treated as the cause of the interference. The noise power ratio at the output of the conventional limiter-discriminator and the improvement factor offered by the new demodulator, obtained with a digital computer, are presented versus baseband frequency in the form of diagrams.

  6. A Novel Hydro-information System for Improving National Weather Service River Forecast System

    NASA Astrophysics Data System (ADS)

    Nan, Z.; Wang, S.; Liang, X.; Adams, T. E.; Teng, W. L.; Liang, Y.

    2009-12-01

    A novel hydro-information system has been developed to improve the forecast accuracy of the NOAA National Weather Service River Forecast System (NWSRFS). An MKF-based (Multiscale Kalman Filter) spatial data assimilation framework, together with the NOAH land surface model, is employed in our system to assimilate satellite surface soil moisture data to yield improved evapotranspiration. The latter are then integrated into the distributed version of the NWSRFS to improve its forecasting skills, especially for droughts, but also for disaster management in general. Our system supports an automated flow into the NWSRFS of daily satellite surface soil moisture data, derived from the TRMM Microwave Imager (TMI) and Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E), and the forcing information of the North American Land Data Assimilation System (NLDAS). All data are custom processed, archived, and supported by the NASA Goddard Earth Sciences Data Information and Services Center (GES DISC). An optional data fusing component is available in our system, which fuses NEXRAD Stage III precipitation data with the NLDAS precipitation data, using the MKF-based framework, to provide improved precipitation inputs. Our system employs a plug-in, structured framework and has a user-friendly, graphical interface, which can display, in real-time, the spatial distributions of assimilated state variables and other model-simulated information, as well as their behaviors in time series. The interface can also display watershed maps, as a result of the integration of the QGIS library into our system. Extendibility and flexibility of our system are achieved through the plug-in design and by an extensive use of XML-based configuration files. Furthermore, our system can be extended to support multiple land surface models and multiple data assimilation schemes, which would further increase its capabilities. Testing of the integration of the current system into the NWSRFS is

  7. Improved illumination system of laparoscopes using an aspherical lens array

    PubMed Central

    Wu, Rengmao; Qin, Yi; Hua, Hong

    2016-01-01

    The current fiber-based illumination systems of laparoscopes are unable to uniformly illuminate a large enough area in abdomen due to the limited numerical aperture (NA) of the fiber bundle. Most energy is concentrated in a small region at the center of the illumination area. This limitation becomes problematic in laparoscopes which require capturing a wide field of view. In this paper, we propose an aspherical lens array which is used to direct the outgoing rays from the fiber bundle of laparoscope to produce a more uniformly illuminated, substantially larger field coverage than standalone fiber source. An intensity feedback method is developed to design the aspherical lens unit for extended non-Lambertian sources, which is the key to the design of this lens array. By this method, the lens unit is obtained after only one iteration, and the lens array is constructed by Boolean operation. Then, the ray-tracing technique is used to verify the design. Further, the lens array is fabricated and experimental tests are performed. The results clearly show that the well-illuminated area is increased to about 0.107m2 from 0.02m2 (about 5x larger than a standard fiber illumination source). More details of the internal organs can be clearly observed under this improved illumination condition, which also reflects the significant improvement in the optical performance of the laparoscope. PMID:27375940

  8. Improved illumination system of laparoscopes using an aspherical lens array.

    PubMed

    Wu, Rengmao; Qin, Yi; Hua, Hong

    2016-06-01

    The current fiber-based illumination systems of laparoscopes are unable to uniformly illuminate a large enough area in abdomen due to the limited numerical aperture (NA) of the fiber bundle. Most energy is concentrated in a small region at the center of the illumination area. This limitation becomes problematic in laparoscopes which require capturing a wide field of view. In this paper, we propose an aspherical lens array which is used to direct the outgoing rays from the fiber bundle of laparoscope to produce a more uniformly illuminated, substantially larger field coverage than standalone fiber source. An intensity feedback method is developed to design the aspherical lens unit for extended non-Lambertian sources, which is the key to the design of this lens array. By this method, the lens unit is obtained after only one iteration, and the lens array is constructed by Boolean operation. Then, the ray-tracing technique is used to verify the design. Further, the lens array is fabricated and experimental tests are performed. The results clearly show that the well-illuminated area is increased to about 0.107m(2) from 0.02m(2) (about 5x larger than a standard fiber illumination source). More details of the internal organs can be clearly observed under this improved illumination condition, which also reflects the significant improvement in the optical performance of the laparoscope. PMID:27375940

  9. The NASA aircraft noise prediction program improved propeller analysis system

    NASA Technical Reports Server (NTRS)

    Nguyen, L. Cathy

    1991-01-01

    The improvements and the modifications of the NASA Aircraft Noise Prediction Program (ANOPP) and the Propeller Analysis System (PAS) are described. Comparisons of the predictions and the test data are included in the case studies for the flat plate model in the Boundary Layer Module, for the effects of applying compressibility corrections to the lift and pressure coefficients, for the use of different weight factors in the Propeller Performance Module, for the use of the improved retarded time equation solution, and for the effect of the number grids in the Transonic Propeller Noise Module. The DNW tunnel test data of a propeller at different angles of attack and the Dowty Rotol data are compared with ANOPP predictions. The effect of the number of grids on the Transonic Propeller Noise Module predictions and the comparison of ANOPP TPN and DFP-ATP codes are studied. In addition to the above impact studies, the transonic propeller noise predictions for the SR-7, the UDF front rotor, and the support of the enroute noise test program are included.

  10. Surface energy and radiation balance systems - General description and improvements

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo J.; Simpson, James R.

    1989-01-01

    Surface evaluation of sensible and latent heat flux densities and the components of the radiation balance were desired for various vegetative surfaces during the ASCOT84 experiment to compare with modeled results and to relate these values to drainage winds. Five battery operated data systems equipped with sensors to determine the above values were operated for 105 station days during the ASCOT84 experiment. The Bowen ratio energy balance technique was used to partition the available energy into the sensible and latent heat flux densities. A description of the sensors and battery operated equipment used to collect and process the data is presented. In addition, improvements and modifications made since the 1984 experiment are given. Details of calculations of soil heat flow at the surface and an alternate method to calculate sensible and latent heat flux densities are provided.

  11. Material Gradients in Oxygen System Components Improve Safety

    NASA Technical Reports Server (NTRS)

    Forsyth, Bradley S.

    2011-01-01

    Oxygen system components fabricated by Laser Engineered Net Shaping (TradeMark) (LENS(TradeMark)) could result in improved safety and performance. LENS(TradeMark) is a near-net shape manufacturing process fusing powdered materials injected into a laser beam. Parts can be fabricated with a variety of elemental metals, alloys, and nonmetallic materials without the use of a mold. The LENS(TradeMark) process allows the injected materials to be varied throughout a single workpiece. Hence, surfaces exposed to oxygen could be constructed of an oxygen-compatible material while the remainder of the part could be one chosen for strength or reduced weight. Unlike conventional coating applications, a compositional gradient would exist between the two materials, so no abrupt material boundary exists. Without an interface between dissimilar materials, there is less tendency for chipping or cracking associated with thermal-expansion mismatches.

  12. Systemic lupus erythematosus: strategies to improve pregnancy outcomes

    PubMed Central

    Yamamoto, Yuriko; Aoki, Shigeru

    2016-01-01

    Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease with a high prevalence in females of childbearing age. Thus, reproduction in SLE patients is a major concern for clinicians. In the past, SLE patients were advised to defer pregnancy because of poor pregnancy outcomes and fear of SLE flares during pregnancy. Investigations to date show that maternal and fetal risks are higher in females with SLE than in the general population. However, with appropriate management of the disease, sufferers may have a relatively uncomplicated pregnancy course. Factors such as appropriate preconception counseling and medication adjustment, strict disease control prior to pregnancy, intensive surveillance during and after pregnancy by both the obstetrician and rheumatologist, and appropriate interventions when necessary play a key role. This review describes the strategies to improve pregnancy outcomes in SLE patients at different time points in the reproduction cycle (preconception, during pregnancy, and postpartum period) and also details the neonatal concerns. PMID:27468250

  13. Raytheon: Compressed Air System Upgrade Saves Energy and Improves Performance

    SciTech Connect

    Not Available

    2005-04-01

    In 2003, Raytheon Company upgraded the efficiency of the compressed air system at its Integrated Air Defense Center in Andover, Massachusetts, to save energy and reduce costs. Worn compressors and dryers were replaced, a more sophisticated control strategy was installed, and an aggressive leak detection and repair effort was carried out. The total cost of these improvements was $342,000; however, National Grid, a utility service provider, contributed a $174,000 incentive payment. Total annual energy and maintenance cost savings are estimated at $141,500, and energy savings are nearly 1.6 million kWh. This case study was prepared for the U.S. Department of Energy's Industrial Technologies Program.

  14. Systemic lupus erythematosus: strategies to improve pregnancy outcomes.

    PubMed

    Yamamoto, Yuriko; Aoki, Shigeru

    2016-01-01

    Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease with a high prevalence in females of childbearing age. Thus, reproduction in SLE patients is a major concern for clinicians. In the past, SLE patients were advised to defer pregnancy because of poor pregnancy outcomes and fear of SLE flares during pregnancy. Investigations to date show that maternal and fetal risks are higher in females with SLE than in the general population. However, with appropriate management of the disease, sufferers may have a relatively uncomplicated pregnancy course. Factors such as appropriate preconception counseling and medication adjustment, strict disease control prior to pregnancy, intensive surveillance during and after pregnancy by both the obstetrician and rheumatologist, and appropriate interventions when necessary play a key role. This review describes the strategies to improve pregnancy outcomes in SLE patients at different time points in the reproduction cycle (preconception, during pregnancy, and postpartum period) and also details the neonatal concerns. PMID:27468250

  15. Stochastic Resonance Improves Broadband Encoding in the Cricket Cercal System.

    NASA Astrophysics Data System (ADS)

    Levin, Jacob

    1996-03-01

    In any physical or biological system a certain amount of environmental noise is unavoidable, and the information therein irrelevant to the organism. Traditionally in signal analysis noise is considered detrimental to the process of signal encoding, and merely a necessary evil to be avoided. It has been observed recently, however, that in some nonlinear systems power from random input noise actually improves the output signal-to-noise ratio (SNR) over a limited operating range, particularly near threshold. This effect is known as stochastic resonance (SR). By taking advantage of SR during the neural encoding process, a cell can optimize its information flow properties. Previous experimental work in SR has investigated only the coding of sinusoidal signals embedded in a broadband white noise background. In this work we demonstrate SR for not only the sine wave case, but also for extended bandwidth stimuli in the presence of white noise, and for cases in which the signal and white noise background frequency spectra are completely non-overlapping. We have investigated the effects of noise on information transfer in the cricket cercal system, a mechanosensory system sensitive to small near-field air particle disturbances, by presenting known wind stimuli to the cricket through audio speakers in a controlled environment along with varying levels of uncorrelated white noise background air current. Spike trains from the second layer of neuronal processing, the primary sensory interneurons, were recorded with intracellular electrodes with the signal and noise presented along the cell's preferred direction. Through the statistical techniques of Shannon's information theory we quantified the amount of information contained in the elicited spike trains about the signal in the various noise environments, as well as the SNR and other measures of the encoding process. An enhancement of output SNR was observed over the entire frequency operating range of the neurons, for almost an

  16. Improvements in Hanford TRU Program Utilizing Systems Modeling and Analyses

    SciTech Connect

    Baynes, P.A.; Bailey, K.B.; McKenney, D.E.; Uytioco, E.

    2008-07-01

    into queues based on their current status in the process. A container can be in only one queue at any given time. Existing data systems are queried to establish the quantity of containers in each queue on any given day. This sets the amount of feed available that is then modeled to be processed according to the daily production plans. The daily production plans were created by identifying the equipment necessary and the staff that performs each process step, and determining the expected production rate for each step. Production performance is monitored on a weekly basis with Project senior staff to establish a total operating efficiency (TOE) for each step (comparing actual performance to production capacity). The unit operations were modeled to be constrained by each day's feed queue plus the performance of the preceding step. The TOE for each unit operation was applied to an integrated model to determine bottlenecks and identify areas for improvement. All of the steps were linked to predict future system performance based on available feed and integrated system-level TOE. It has been determined that at times sub-optimization of a particular unit operation is necessary to ensure the system remains balanced (e.g., having excess capacity in assay does no good if there is no feed available because the real-time radiography [RTR] is working at half capacity). Several recommendations have been provided to the Project management team resulting in improvements in the performance of TRU certification activities by Hanford's TRU Program. (authors)

  17. The 5 Hour Pulse Period and Broadband Spectrum of the Symbiotic X-Ray Binary 3A 1954+319

    NASA Technical Reports Server (NTRS)

    Marcu, Diana M.; Fuerst, Felix; Pottschmidt, Katja; Grinberg, Victoria; Miller, Sebstian; Wilms, Joern; Postnov, Konstantin A.; Corbet, Robin H. D.; Markwardt, Craig B.; Cadolle Bel, Marion

    2011-01-01

    We present an analysis of the highly variable accreting X-ray pulsar 3A 1954+319 using 2005-2009 monitoring data obtained with INTEGRAL and Swift. This considerably extends the pulse period history and covers flaring episodes in 2005 and 2008. In 2006 the source was identified as one of only a few known symbiotic X-ray binaries, Le" systems composed of a neutron star accreting from the inhomogeneous medium around an M-giant star. The extremely long pulse period of approximately 5.3 h is directly visible in the 2008 INTEGRAL-ISGRI outburst light curve. The pulse profile is double peaked and not significantly energy dependent. During the outburst a strong spin-up of -1.8 x 10(exp -4) h h(exp -1) occurred. Between 2005 and 2008 a long term spin-down trend of 2.1 x 10(exp -5) h h(exp -1) was observed for the first time for this source. The 3-80 keV pulse peak spectrum of 3A 1954+319 during the 2008 flare could be well described by a thermal Comptonization model. We interpret the results within the framework of a recently developed quasi-spherical accretion model for symbiotic X-ray binaries.

  18. Recent X-ray observations of the symbiotic star AG Peg: do they signify Colliding Stellar Winds?

    NASA Astrophysics Data System (ADS)

    Zhekov, Svetozar A.; Tomov, Toma

    2016-06-01

    We present an analysis of recent X-ray observations of the symbiotic star AG Peg. The X-ray emission of AG Peg as observed with Swift in 2015 shows considerable variability on time scale of days as variability on shorter time scales might be present as well. Analysis of the X-ray spectra obtained in 2013 and 2015 confirms that AG Peg is an X-ray source of class β of the X-ray sources amongst the symbiotic stars. The X-ray emission of AG Peg as observed with ROSAT (1993 June) might well originate from colliding stellar winds (CSW) in binary system. On the other hand, the characteristics of the X-ray emission of AG Peg in 2013 and 2015 (Swift) are hard to accommodate in the framework of the CSW picture. Analysis of the light curves in 2015 shows that the power spectrum of the X-ray variability in AG Peg resembles that of the flicker noise (or flickering) being typical for accretion processes in astronomical objects. This is a sign that CSWs did not play a key role for the X-ray emission from AG Peg in 2013-2015 and a different mechanism (probably accretion) is also getting into play.

  19. Mass-loss Rate by the Mira in the Symbiotic Binary V1016 Cygni from Raman Scattering

    NASA Astrophysics Data System (ADS)

    Sekeráš, M.; Skopal, A.

    2015-10-01

    The mass-loss rate from Mira variables represents a key parameter in our understanding of their evolutionary tracks. We introduce a method for determining the mass-loss rate from the Mira component in D-type symbiotic binaries via the Raman scattering of atomic hydrogen in the wind from the giant. Using our method, we investigated Raman He ii λ 1025\\to λ 6545 conversion in the spectrum of the symbiotic Mira V1016 Cyg. We determined its efficiency, η = 0.102, 0.148, and the corresponding mass-loss rate, \\dot{M}={2.0}-0.2+0.1× {10}-6, {2.7}-0.1+0.2× {10}-6 {M}⊙ {{{yr}}}-1, using our spectra from 2006 April and 2007 July, respectively. Our values of \\dot{M} that we derived from Raman scattering are comparable with those obtained independently by other methods. Applying the method to other Mira-white dwarf binary systems can provide a necessary constraint in the calculation of asymptotic giant branch (AGB) evolution.

  20. Recent X-ray observations of the symbiotic star AG Peg: do they signify colliding stellar winds?

    NASA Astrophysics Data System (ADS)

    Zhekov, Svetozar A.; Tomov, Toma

    2016-09-01

    We present an analysis of recent X-ray observations of the symbiotic star AG Peg. The X-ray emission of AG Peg as observed with Swift in 2015 shows considerable variability on time-scale of days as variability on shorter time-scales might be present as well. Analysis of the X-ray spectra obtained in 2013 and 2015 confirms that AG Peg is an X-ray source of class β of the X-ray sources amongst the symbiotic stars. The X-ray emission of AG Peg as observed with ROSAT (1993 June) might well originate from colliding stellar winds (CSWs) in binary system. On the other hand, the characteristics of the X-ray emission of AG Peg in 2013 and 2015 (Swift) are hard to accommodate in the framework of the CSW picture. Analysis of the light curves in 2015 shows that the power spectrum of the X-ray variability in AG Peg resembles that of the flicker noise (or flickering) being typical for accretion processes in astronomical objects. This is a sign that CSWs did not play a key role for the X-ray emission from AG Peg in 2013-2015 and a different mechanism (probably accretion) is also getting into play.

  1. Molecular phylogeny of symbiotic dinoflagellates from planktonic foraminifera and radiolaria.

    PubMed

    Gast, R J; Caron, D A

    1996-11-01

    Recent analyses of the small subunit ribosomal DNA (srDNA) from dinoflagellate symbionts of cnidaria have confirmed historical descriptions of a diverse but well-defined clade, Symbiodinium, as well as several other independent symbiont lineages (Rowan 1991; Rowan and Powers 1992; Sadler et al. 1992; McNally et al 1994). Dinoflagellates also occur as intracellular symbionts in a number of pelagic protistan taxa, but the srDNA of these symbionts has not been examined. We analyzed the srDNA sequences of the symbiotic dinoflagellates from four planktonic foraminiferal species and six radiolarian species. The symbionts from these sarcodines formed two distinct lineages within the dinoflagellates. Within each lineage, symbionts obtained from different host species showed few, if any, srDNA sequence differences. The planktonic foraminiferal symbionts were most closely related to Gymnodinium simplex and the Symbiodinium clade, whereas the radiolarian symbionts were most closely related to the dinoflagellate symbiont from the oceanic chondrophore, Velella velella. Therefore, although the dinoflagellate symbionts of foraminifera appear to be a sister taxon of the symbionts from benthic foraminifera and invertebrates, the symbionts of radiolaria are distinct and arose from an independent lineage of dinoflagellate symbionts that shares common ancestry with the symbiont of at least one pelagic metazoan. The lack of srDNA variability within the sarcodine symbiont lineages suggests that coevolution of host and symbiont has not occurred. PMID:8896371

  2. Journalists and public health professionals: challenges of a symbiotic relationship.

    PubMed

    Lubens, Pauline

    2015-02-01

    Journalists and health professionals share a symbiotic relationship during a disease outbreak as both professions play an important role in informing the public's perceptions and the decisions of policy makers. Although critics in the United States have focused on US reporters and media outlets whose coverage has been sensationalist and alarmist, the discussion in this article is based on the ideal--gold standard--for US journalists. Journalists perform three primary functions during times of health crises: disseminating accurate information to the public, medical professionals, and policy makers; acting as the go-between for the public and decision makers and health and science experts; and monitoring the performance of institutions responsible for the public health response. A journalist's goal is to responsibly inform the public in order to optimize the public health goals of prevention while minimizing panic. The struggle to strike a balance between humanizing a story and protecting the dignity of patients while also capturing the severity of an epidemic is harder in the era of the 24-7 news cycle. Journalists grapple with dueling pressures: confirming that their information is correct while meeting the demand for rapid updates. Just as health care professionals triage patients, journalists triage information. The challenge going forward will be how to get ahead of the story from the onset, racing against the pace of digital dissemination of misinformation by continuing to refine the media-science relationship. PMID:25382141

  3. Candidates for Symbiotic Control of Sugarcane White Leaf Disease

    PubMed Central

    Wangkeeree, Jureemart; Miller, Thomas A.

    2012-01-01

    The leafhopper Matsumuratettix hiroglyphicus (Matsumura) is the most important vector of a phytoplasma pathogen causing sugarcane white leaf (SCWL) disease. The purpose of this study was to evaluate candidate bacterial symbionts for possible use as vehicles in the control of the disease. 16S rRNA bacterial genes were amplified from whole bodies of M. hiroglyphicus leafhoppers and analyzed by cloning and sequencing. Two dominant groups were found: one belonged to the Betaproteobacteria that did not closely match any sequences in the database and was named bacterium associated with M. hiroglyphicus (BAMH). Another one found to be abundant in this leafhopper is “Candidatus Sulcia muelleri” in the order Bacteroidetes, which was previously reported in the insect members of the Auchenorrhyncha. Most M. hiroglyphicus leafhoppers carry both BAMH and “Ca. Sulcia muelleri.” Fluorescent in situ hybridization showed that BAMH and “Ca. Sulcia muelleri” colocalized in the same bacteriomes. BAMH was present in the midgut and ovaries of the leafhopper and was found in all developmental stages, including eggs, nymphs, and adults. Because BAMH appears to be specific for the SCWL vector, we evaluated it as a candidate for symbiotic control of sugarcane white leaf disease. PMID:22798373

  4. The anomalous C 4 intensity ratio in symbiotic stars

    NASA Technical Reports Server (NTRS)

    Michalitsianos, A. G.; Kafatos, M.; Fahey, R. P.

    1988-01-01

    The C IV lambda lambda 1548.2,1550.8 resonance doublet in a symbiotic stars was shown to exhibit anomalous line intensity ratios in which I (lambda 1548.2)/I(lambda 1550.8) less than 1, or less than the optically-thick limit of unity. The R Aquarii-central HII region and RX Puppis exhibit this phenomena. The I(lambda 1548.2)/I(lambda 1550.8) ratio in RX Puppis is found to vary inversely with the total C IV line intensity, and with the FES-visual light, as the object declined over a 5 yr period following a brightening in UV and optical emission which peaked in 1982. This doublet intensity behavior could be explained by a wind which has a narrow velocity range of 600 approx. less than sup v wind approx. less than 1000 km/sec, or by the pumping of the Fe II (mul. 45.01) transition a sup 4 F sub 9/2 - y sup 4 H(o) sub 11/2 by C IV lambda 1548.2, which effectively scatters C IV photons into the Fe II spectrum in these objects.

  5. Cell cultures from the symbiotic soft coral Sinularia flexibilis.

    PubMed

    Khalesi, Mohammad K; Vera-Jiménez, N I; Aanen, D K; Beeftink, H H; Wijffels, R H

    2008-01-01

    The symbiotic octocoral Sinularia flexibilis is a producer of potential pharmaceuticals. Sustainable mass production of these corals as a source of such compounds demands innovative approaches, including coral cell culture. We studied various cell dissociation methodologies and the feasibility of cultivation of S. flexibilis cells on different media and cell dissociation methodologies. Mechanical dissociation of coral tissue always yielded the highest number of cells and allowed subsequent cellular growth in all treatments. The best results from chemical dissociation reagents were found with trypsin-ethylene diamine tetraacetic acid. Coral cells obtained from spontaneous dissociation did not grow. Light intensity was found to be important for coral cell culture showing an enduring symbiosis between the cultured cells and their intracellular algae. The Grace's insect medium and Grace's modified insect medium were found to be superior substrates. To confirm the similarity of the cultured cells and those in the coral tissue, a molecular test with Internal Transcribed Spacer primers was performed. Thereby, the presence of similar cells of both the coral cells and zooxanthella in different culture media was confirmed. PMID:18661193

  6. Symbiotic Stars in X-Rays. III. Suzaku Observations

    NASA Astrophysics Data System (ADS)

    Nuñez, N. E.; Nelson, T.; Mukai, K.; Sokoloski, J. L.; Luna, G. J. M.

    2016-06-01

    We describe the X-ray emission as observed by Suzaku from five symbiotic stars that we selected for deep Suzaku observations after their initial detection with ROSAT, ASCA, and Swift. We find that the X-ray spectra of all five sources can be adequately fit with absorbed optically thin thermal plasma models, with either single- or multi-temperature plasmas. These models are compatible with the X-ray emission originating in the boundary layer between an accretion disk and a white dwarf. The high plasma temperatures of kT > 3 keV for all five targets were greater than expected for colliding winds. Based on these high temperatures as well as previous measurements of UV variability and UV luminosity and the large amplitude of X-ray flickering in 4 Dra, we conclude that all five sources are accretion-powered through predominantly optically thick boundary layers. Our X-ray data allow us to observe a small optically thin portion of the emission from these boundary layers. Given the time between previous observations and these observations, we find that the intrinsic X-ray flux and the intervening absorbing column can vary by factors of three or more on a timescale of years. However, the location of the absorber and the relationship between changes in accretion rate and absorption are still elusive.

  7. Cristispira from oyster styles: complex morphology of large symbiotic spirochetes

    NASA Technical Reports Server (NTRS)

    Margulis, L.; Nault, L.; Sieburth, J. M.

    1991-01-01

    Crystalline styles (digestive organs) of bivalve mollusks provide the habitat for highly motile bacteria. Styles from freshly-collected oysters, Crassostrea virginica, were studied by electron microscopy; Cristispira spirochetes were abundant in these organs. Detailed study reveals these spirochetes to be among the most complex prokaryotic cells known. More than 600 periplasmic flagella and an adhering outer lipoprotein membrane (e.g., a 270 degrees sillon) form the ultrastructural basis for the "crista," first described by light microscopy. Unique rosette structures corresponding to the "chambers" or "ovoid inclusions" of light microscopy were detected at the periphery of all protoplasmic cylinders. Polar organelles and linearly aligned flagellar insertions are conspicuous. In size and complexity, Cristispira more resembles Pillotina, Diplocalyx, Clevelandina and Hollandina (large spirochetes symbiotic in termites) than it does Treponema. Cristispira pectinis (Gross, 1910), the type species; Spirillum ostrea (Noguchi, 1921); and another, less frequent bacterial symbiont are the predominant inhabitants of the dense style matrix. The ultrastructure of the spirillum and an electron micrograph of the third bacterium are shown.

  8. Improved VLBI measurement of the solar system acceleration

    NASA Astrophysics Data System (ADS)

    Titov, O.; Lambert, S.

    2013-11-01

    Aims: We propose new estimates of the secular aberration drift, which is mainly caused by the rotation of the solar system about the Galactic center, based on up-to-date VLBI observations and improved method of outlier elimination. Methods: We fitted degree-2 vector spherical harmonics to the extragalactic radio source proper motion field derived from geodetic VLBI observations during 1979-2013. We paid particular attention to the outlier elimination procedure that removes outliers from (i) radio source coordinate time series and (ii) the proper motion sample. Results: We obtain more accurate values of the Solar system acceleration than in our previous paper. The acceleration vector is oriented towards the Galactic center within ~7°. The component perpendicular to the Galactic plane is statistically insignificant. We show that an insufficient cleaning of the data set can lead to strong variations in the dipole amplitude and orientation, and hence to statistically biased results. Proper motion data used for the DR solution is only available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/559/A95

  9. Automatic graphene transfer system for improved material quality and efficiency

    PubMed Central

    Boscá, Alberto; Pedrós, Jorge; Martínez, Javier; Palacios, Tomás; Calle, Fernando

    2016-01-01

    In most applications based on chemical vapor deposition (CVD) graphene, the transfer from the growth to the target substrate is a critical step for the final device performance. Manual procedures are time consuming and depend on handling skills, whereas existing automatic roll-to-roll methods work well for flexible substrates but tend to induce mechanical damage in rigid ones. A new system that automatically transfers CVD graphene to an arbitrary target substrate has been developed. The process is based on the all-fluidic manipulation of the graphene to avoid mechanical damage, strain and contamination, and on the combination of capillary action and electrostatic repulsion between the graphene and its container to ensure a centered sample on top of the target substrate. The improved carrier mobility and yield of the automatically transferred graphene, as compared to that manually transferred, is demonstrated by the optical and electrical characterization of field-effect transistors fabricated on both materials. In particular, 70% higher mobility values, with a 30% decrease in the unintentional doping and a 10% strain reduction are achieved. The system has been developed for lab-scale transfer and proved to be scalable for industrial applications. PMID:26860260

  10. Automatic graphene transfer system for improved material quality and efficiency

    NASA Astrophysics Data System (ADS)

    Boscá, Alberto; Pedrós, Jorge; Martínez, Javier; Palacios, Tomás; Calle, Fernando

    2016-02-01

    In most applications based on chemical vapor deposition (CVD) graphene, the transfer from the growth to the target substrate is a critical step for the final device performance. Manual procedures are time consuming and depend on handling skills, whereas existing automatic roll-to-roll methods work well for flexible substrates but tend to induce mechanical damage in rigid ones. A new system that automatically transfers CVD graphene to an arbitrary target substrate has been developed. The process is based on the all-fluidic manipulation of the graphene to avoid mechanical damage, strain and contamination, and on the combination of capillary action and electrostatic repulsion between the graphene and its container to ensure a centered sample on top of the target substrate. The improved carrier mobility and yield of the automatically transferred graphene, as compared to that manually transferred, is demonstrated by the optical and electrical characterization of field-effect transistors fabricated on both materials. In particular, 70% higher mobility values, with a 30% decrease in the unintentional doping and a 10% strain reduction are achieved. The system has been developed for lab-scale transfer and proved to be scalable for industrial applications.

  11. Quality improvement and accountability in the Danish health care system.

    PubMed

    Mainz, Jan; Kristensen, Solvejg; Bartels, Paul

    2015-12-01

    Denmark has unique opportunities for quality measurement and benchmarking since Denmark has well-developed health registries and unique patient identifier that allow all registries to include patient-level data and combine data into sophisticated quality performance monitoring. Over decades, Denmark has developed and implemented national quality and patient safety initiatives in the healthcare system in terms of national clinical guidelines, performance and outcome measurement integrated in clinical databases for important diseases and clinical conditions, measurement of patient experiences, reporting of adverse events, national handling of patient complaints, national accreditation and public disclosure of all data on the quality of care. Over the years, Denmark has worked up a progressive and transparent just culture in quality management; the different actors at the different levels of the healthcare system are mutually attentive and responsive in a coordinated effort for quality of the healthcare services. At national, regional, local and hospital level, it is mandatory to participate in the quality initiatives and to use data and results for quality management, quality improvement, transparency in health care and accountability. To further develop the Danish governance model, it is important to expand the model to the primary care sector. Furthermore, a national quality health programme 2015-18 recently launched by the government supports a new development in health care focusing upon delivering high-quality health care-high quality is defined by results of value to the patients. PMID:26443814

  12. COOLING FAN AND SYSTEM PERFORMANCE AND EFFICIENCY IMPROVEMENTS

    SciTech Connect

    Ronald Dupree

    2005-07-31

    Upcoming emissions regulations (Tiers 3, 4a and 4b) are imposing significantly higher heat loads on the cooling system than lesser regulated machines. This work was a suite of tasks aimed at reducing the parasitic losses of the cooling system, or improving the design process through six distinct tasks: 1. Develop an axial fan that will provide more airflow, with less input power and less noise. The initial plan was to use Genetic Algorithms to do an automated fan design, incorporating forward sweep for low noise. First and second generation concepts could not meet either performance or sound goals. An experienced turbomachinery designer, using a specialized CFD analysis program has taken over the design and has been able to demonstrate a 5% flow improvement (vs 10% goal) and 10% efficiency improvement (vs 10% goal) using blade twist only. 2. Fan shroud developments, using an 'aeroshroud' concept developed at Michigan State University. Performance testing at Michigan State University showed the design is capable of meeting the goal of a 10% increase in flow, but over a very narrow operating range of fan performance. The goal of 10% increase in fan efficiency was not met. Fan noise was reduced from 0 to 2dB, vs. a goal of 5dB at constant airflow. The narrow range of fan operating conditions affected by the aeroshroud makes this concept unattractive for further development at this time 3. Improved axial fan system modeling is needed to accommodate the numbers of cooling systems to be redesigned to meet lower emissions requirements. A CFD fan system modeling guide has been completed and transferred to design engineers. Current, uncontrolled modeling practices produce flow estimates in some cases within 5% of measured values, and in some cases within 25% of measured values. The techniques in the modeling guide reduced variability to the goal of + 5% for the case under study. 4. Demonstrate the performance and design versatility of a high performance fan. A 'swept blade

  13. Automatic graphene transfer system for improved material quality and efficiency.

    PubMed

    Boscá, Alberto; Pedrós, Jorge; Martínez, Javier; Palacios, Tomás; Calle, Fernando

    2016-01-01

    In most applications based on chemical vapor deposition (CVD) graphene, the transfer from the growth to the target substrate is a critical step for the final device performance. Manual procedures are time consuming and depend on handling skills, whereas existing automatic roll-to-roll methods work well for flexible substrates but tend to induce mechanical damage in rigid ones. A new system that automatically transfers CVD graphene to an arbitrary target substrate has been developed. The process is based on the all-fluidic manipulation of the graphene to avoid mechanical damage, strain and contamination, and on the combination of capillary action and electrostatic repulsion between the graphene and its container to ensure a centered sample on top of the target substrate. The improved carrier mobility and yield of the automatically transferred graphene, as compared to that manually transferred, is demonstrated by the optical and electrical characterization of field-effect transistors fabricated on both materials. In particular, 70% higher mobility values, with a 30% decrease in the unintentional doping and a 10% strain reduction are achieved. The system has been developed for lab-scale transfer and proved to be scalable for industrial applications. PMID:26860260

  14. Foundations for Improvements to Passive Detection Systems - Final Report

    SciTech Connect

    Labov, S E; Pleasance, L; Sokkappa, P; Craig, W; Chapline, G; Frank, M; Gronberg, J; Jernigan, J G; Johnson, S; Kammeraad, J; Lange, D; Meyer, A; Nelson, K; Pohl, B; Wright, D; Wurtz, R

    2004-10-07

    This project explores the scientific foundation and approach for improving passive detection systems for plutonium and highly enriched uranium in real applications. Sources of gamma-ray radiation of interest were chosen to represent a range of national security threats, naturally occurring radioactive materials, industrial and medical radiation sources, and natural background radiation. The gamma-ray flux emerging from these sources, which include unclassified criticality experiment configurations as surrogates for nuclear weapons, were modeled in detail. The performance of several types of gamma-ray imaging systems using Compton scattering were modeled and compared. A mechanism was created to model the combine sources and background emissions and have the simulated radiation ''scene'' impinge on a model of a detector. These modeling tools are now being used in various projects to optimize detector performance and model detector sensitivity in complex measuring environments. This study also developed several automated algorithms for isotope identification from gamma-ray spectra and compared these to each other and to algorithms already in use. Verification testing indicates that these alternative isotope identification algorithms produced less false positive and false negative results than the ''GADRAS'' algorithms currently in use. In addition to these algorithms that used binned spectra, a new approach to isotope identification using ''event mode'' analysis was developed. Finally, a technique using muons to detect nuclear material was explored.

  15. [Symbiotic matching between soybean cultivar Luhuang No. 1 and different rhizobia].

    PubMed

    Ji, Zhao-jun; Wang, Fei-meng; Wang, Su-ge; Yang, Sheng-hui; Guo, Rui; Tang, Ru-you; Chen, Wen-xin; Chen, Wen-feng

    2014-12-01

    Soybean plants could establish symbiosis and fix nitrogen with different rhizobial species in the genera of Sinorhizobium and Bradyrhizobium. Studies on the symbiotic matching between soybean cultivars and different rhizobial species are theoretically and practically important for selecting effective strains used to inoculate the plants and improve the soybean production and quality. A total of 27 strains were isolated and purified from a soil sample of Huanghuaihai area by using the soybean cultivar Luhang No. 1, a protein-rich cultivar grown in that area, as the trapping plants. These strains were identified as members of Sinorhizobium (18 strains) and Bradyrhizobium (9 strains) based on the sequence analysis of housekeeping gene recA. Two representative strains (Sinorhizobium fredii S6 and Bradyrhizobium sp. S10) were used to inoculate the seeds of Luhang No. 1 alone or mixed, in pots filled with vermiculite or soil, and in the field trial to investigate their effects on soybean growth, nodulation, nitrogen fixation activity, yield, contents of protein and oil in seeds. The results demonstrated that strain S6 showed better effects on growth-promotion, yield of seeds and seed quality than strain S10. Thus strain S6 was finally regarded as the effective rhizobium matching to soybean Luhuang No. 1, which could be the candidate as a good inoculant for planting the soybean Luhuang No. 1 at a large scale in the Huanghuaihai area. PMID:25876410

  16. Symbiotic role of Glomus mosseae in phytoextraction of lead in vetiver grass [Chrysopogon zizanioides (L.)].

    PubMed

    Punamiya, Pravin; Datta, Rupali; Sarkar, Dibyendu; Barber, Summer; Patel, Mandakini; Das, Padmini

    2010-05-15

    Lead (Pb) has limited solubility in the soil environment owing to complexation with various soil components. Although total soil Pb concentrations may be high at a given site, the fraction of soluble Pb that plants can extract is very small, which is the major limiting factor for Pb phytoremediation. The symbiotic effect of arbuscular mycorrhizal (AM) fungus, Glomus mosseae was examined on growth and phytoextraction of lead (Pb) by vetiver grass [Chrysopogon zizanioides (L.)]. A hydroponic study, Phase I (0, 1, 2, and 4mM Pb) was conducted followed by an incubation pot study, Phase II (0, 400, 800, and 1200 mg kg(-1) Pb) where vetiver plants were colonized with G. mosseae. The results obtained indicate that plants colonized by the AM fungi not only exhibit better growth (increase in plant biomass), but also significantly increase Pb uptake in root and higher translocation to the shoot at all given treatments. Moreover, plants colonized with AM fungi had higher chlorophyll content and reduced levels of low molecular weight thiols, indicating the ability to better tolerate metal-induced stress. Results from this study indicate that vetiver plants in association with AM fungi can be used for improved phytoextraction of Pb from contaminated soil. PMID:20061082

  17. Improved Refractories for Slagging Gasifiers in IGCC Power Systems

    SciTech Connect

    Dogan, Cynthia P.; Kwong, Kyei-Sing; Bennett, James P.; Chinn, Richard E.

    2003-04-24

    The gasification of coal and other carbon-containing fuels provides the opportunity to produce energy more efficiently, and with significantly less environmental impact, than more-conventional combustion-based processes. In addition, the synthesis gas that is the product of the gasification process offers the option of ''polygeneration,'' i.e., the production of alternative products instead of power should it be economically favorable to do so. Because of these advantages, gasification is viewed as one of the key processes in the U.S. Department of Energy's Vision 21 power system. However, issues with both the reliability and the economics of gasifier operation will have to be resolved before gasification will be widely adopted by the power industry. Central to both enhanced reliability and economics is the development of materials with longer service lives in gasifier systems that can provide extended periods of continuous, trouble-free gasifier operation. The focus of the Advanced Refractories for Gasification project at the Albany Research Center is to develop improved refractory materials capable of withstanding the harsh, high-temperature environment created by the gasification reaction, and includes both the refractory lining that protects and insulates the slagging gasifier, as well as the thermocouple assemblies that are utilized to monitor gasifier operating temperatures. Current generation refractory liners in slagging gasifiers are typically replaced every four to 18 months, at costs ranging up to $2,000,000, depending upon the size of the gasification vessel. Compounding materials and installation costs are the lost-opportunity costs for the time that the gasifier is off-line for the refractory exchange. Current generation thermocouple devices rarely survive the gasifier start-up process, leaving the operator with no real means of temperature measurement during routine operation. Reliable, efficient, and economical gasifier operation that includes the

  18. 76 FR 62164 - VASRD Improvement Forum-Updating Disability Criteria for the Respiratory System, Cardiovascular...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-06

    ... AFFAIRS VASRD Improvement Forum--Updating Disability Criteria for the Respiratory System, Cardiovascular...) Improvement Forum-- Updating Disability Criteria for the Respiratory System, Cardiovascular System, Hearing... four body systems: (1) Respiratory System (38 CFR 4.96-4.97), (2) the Cardiovascular System (38 CFR...

  19. Improving collaboration by standardization efforts in systems biology.

    PubMed

    Dräger, Andreas; Palsson, Bernhard Ø

    2014-01-01

    Collaborative genome-scale reconstruction endeavors of metabolic networks would not be possible without a common, standardized formal representation of these systems. The ability to precisely define biological building blocks together with their dynamic behavior has even been considered a prerequisite for upcoming synthetic biology approaches. Driven by the requirements of such ambitious research goals, standardization itself has become an active field of research on nearly all levels of granularity in biology. In addition to the originally envisaged exchange of computational models and tool interoperability, new standards have been suggested for an unambiguous graphical display of biological phenomena, to annotate, archive, as well as to rank models, and to describe execution and the outcomes of simulation experiments. The spectrum now even covers the interaction of entire neurons in the brain, three-dimensional motions, and the description of pharmacometric studies. Thereby, the mathematical description of systems and approaches for their (repeated) simulation are clearly separated from each other and also from their graphical representation. Minimum information definitions constitute guidelines and common operation protocols in order to ensure reproducibility of findings and a unified knowledge representation. Central database infrastructures have been established that provide the scientific community with persistent links from model annotations to online resources. A rich variety of open-source software tools thrives for all data formats, often supporting a multitude of programing languages. Regular meetings and workshops of developers and users lead to continuous improvement and ongoing development of these standardization efforts. This article gives a brief overview about the current state of the growing number of operation protocols, mark-up languages, graphical descriptions, and fundamental software support with relevance to systems biology. PMID:25538939

  20. Improving Collaboration by Standardization Efforts in Systems Biology

    PubMed Central

    Dräger, Andreas; Palsson, Bernhard Ø.

    2014-01-01

    Collaborative genome-scale reconstruction endeavors of metabolic networks would not be possible without a common, standardized formal representation of these systems. The ability to precisely define biological building blocks together with their dynamic behavior has even been considered a prerequisite for upcoming synthetic biology approaches. Driven by the requirements of such ambitious research goals, standardization itself has become an active field of research on nearly all levels of granularity in biology. In addition to the originally envisaged exchange of computational models and tool interoperability, new standards have been suggested for an unambiguous graphical display of biological phenomena, to annotate, archive, as well as to rank models, and to describe execution and the outcomes of simulation experiments. The spectrum now even covers the interaction of entire neurons in the brain, three-dimensional motions, and the description of pharmacometric studies. Thereby, the mathematical description of systems and approaches for their (repeated) simulation are clearly separated from each other and also from their graphical representation. Minimum information definitions constitute guidelines and common operation protocols in order to ensure reproducibility of findings and a unified knowledge representation. Central database infrastructures have been established that provide the scientific community with persistent links from model annotations to online resources. A rich variety of open-source software tools thrives for all data formats, often supporting a multitude of programing languages. Regular meetings and workshops of developers and users lead to continuous improvement and ongoing development of these standardization efforts. This article gives a brief overview about the current state of the growing number of operation protocols, mark-up languages, graphical descriptions, and fundamental software support with relevance to systems biology. PMID:25538939

  1. Symbiotic relationship analysis of predominant bacteria in a lab-scale anammox UASB bioreactor.

    PubMed

    Wang, Yujia; Hu, Xiaomin; Jiang, Binhui; Song, Zhenhui; Ma, Yongguang

    2016-04-01

    In order to provide the comprehensive insight into the key microbial groups in anaerobic ammonium oxidation (anammox) process, high-throughput sequencing analysis has been used for the investigation of the bacterial communities of a lab-scale upflow anaerobic sludge bed (UASB) anammox bioreactor. Results revealed that 109 operational taxonomic units (OTUs; out of 14,820 reads) were identified and a domination of anammox bacteria of Candidatus Kuenenia stuttgartiensis (OTU474, 35.42 %), along with heterotrophs of Limnobacter sp. MED105 (OTU951, 14.98 %), Anerolinea thermophila UNI-1 (OTU465 and OTU833, 6.60 and 3.93 %), Azoarcus sp. B72 (OTU26, 9.47 %), and Ignavibacterium sp. JCM 16511 (OTU459, 8.33 %) were detected. Metabolic pathway analysis showed that Candidatus K. stuttgartiensis encountered gene defect in synthesizing a series of metabolic cofactors for growth, implying that K. stuttgartiensis is auxotrophic. Coincidentally, the other dominant species severally showed complete metabolic pathways with full set gene encoding to corresponding cofactors presented in the surrounding environment. Furthermore, it was likely that the survival of heterotrophs in the autotrophic system indicates the existence of a symbiotic and mutual relationship in anammox system. PMID:26739990

  2. Symbiotic effectiveness of inoculation with Bradyrhizobium isolates on soybean [Glycine max (L.) Merrill] genotypes with different maturities.

    PubMed

    Argaw, Anteneh

    2014-01-01

    The influence of soybean genotypes with different maturity groups on the symbiotic effectiveness of Bradyrhizobium spp under high native soil N is not well known. Therefore, the objective of this work was to evaluate the influence of maturity time of soybean genotypes on the symbiotic effectiveness of Bradyrhizobium spp. at higher soil N. Three isolates of Bradyrhizobium spp. (UK-isolate, TAL-379 isolate and local-isolate) and six soybean genotypes, three late maturing (Wogayen, TGx-1336424 and Belsa) and three medium maturing (GIZA, Afgat and Gishame) were used for greenhouse experiment. Only GIZA and TGx-1336424 were selected for field experiment. The result of the experiments showed that significantly (P < 0.05) differences in all investigated traits, except total plant tissue N, was observed in TGx-1336424 with UK-Isolate and Local-Isolate.TAL-379 inoculation performed better in all investigated traits of GIZA genotype than other inoculation treatments. N-fertilization in the greenhouse experiment significantly (P < 0.05) improved the shoot biomass of Wogayen and Belsa-95, but did not observe in GIZA and Gishame. The regression analysis obtained between nodule number and nodule dry weight with that of grain yield indicated generally higher R(2) value for late maturing than that of the medium maturing genotypes. This indicates high importance of nodulation for improving the GY of late maturing genotypes. Hence, this study proves the need for inoculation to improve the production and productivity of soybean sustainably in Ethiopia, with particularly pronounced effect on late maturing genotypes of soybean. PMID:26034703

  3. Improving land vehicle situational awareness using a distributed aperture system

    NASA Astrophysics Data System (ADS)

    Fortin, Jean; Bias, Jason; Wells, Ashley; Riddle, Larry; van der Wal, Gooitzen; Piacentino, Mike; Mandelbaum, Robert

    2005-05-01

    U.S. Army Research, Development, and Engineering Command (RDECOM) Communications Electronics Research, Development and Engineering Center (CERDEC) Night Vision and Electronic Sensors Directorate (NVESD) has performed early work to develop a Distributed Aperture System (DAS). The DAS aims at improving the situational awareness of armored fighting vehicle crews under closed-hatch conditions. The concept is based on a plurality of sensors configured to create a day and night dome of surveillance coupled with heads up displays slaved to the operator's head to give a "glass turret" feel. State-of-the-art image processing is used to produce multiple seamless hemispherical views simultaneously available to the vehicle commander, crew members and dismounting infantry. On-the-move automatic cueing of multiple moving/pop-up low silhouette threats is also done with the possibility to save/revisit/share past events. As a first step in this development program, a contract was awarded to United Defense to further develop the Eagle VisionTM system. The second-generation prototype features two camera heads, each comprising four high-resolution (2048x1536) color sensors, and each covering a field of view of 270°hx150°v. High-bandwidth digital links interface the camera heads with a field programmable gate array (FPGA) based custom processor developed by Sarnoff Corporation. The processor computes the hemispherical stitch and warp functions required for real-time, low latency, immersive viewing (360°hx120°v, 30° down) and generates up to six simultaneous extended graphics array (XGA) video outputs for independent display either on a helmet-mounted display (with associated head tracking device) or a flat panel display (and joystick). The prototype is currently in its last stage of development and will be integrated on a vehicle for user evaluation and testing. Near-term improvements include the replacement of the color camera heads with a pixel-level fused combination of

  4. Transient Stability Improvement of Multi-Machine Power System with Large-Capacity Battery Systems

    NASA Astrophysics Data System (ADS)

    Kawabe, Ken-Ichi; Yokoyama, Akihiko

    An emergency control has been applied to power systems to avoid cascading outages by making the best use of existing equipment under severe fault conditions. Battery energy storage system (BESS) is one of the attractive equipment for the emergency control according to its growing installed capacity in the current grid. This paper investigates an effective use of BESS for transient stability improvement, and proposes a novel control scheme using wide-area information. The proposed control scheme adopts two stability indices, the energy function and rotor speed of the critical machine, to make it applicable to multi-machine power systems. Besides, it can control active and reactive power injection of the BESS coordinately to make the best use of its converter capacity for the stability enhancement. Digital simulations are conducted on the 32-machine meshed system with multiple BESSs. The results demonstrate that the BESSs controlled by the proposed method can improve the first swing stability and the system damping, and it is made clear how they improve the transient stability of the multi-machine power system. In addition, an impact of the reactive power control on the bus voltages around the installation sites is investigated to discuss a preferable way of their installation.

  5. Training for Leadership in Local Educational Improvement Programs. Unit 10. Diffusing Educational Improvement Programs Within a School System.

    ERIC Educational Resources Information Center

    Floor, Lucretia J.

    This unit is concerned with problems and strategies involved in achieving systemwide improvements within a school district rather than having such improvements occur only in a fraction of classrooms or schools. A person who completes this unit should be able to accomplish the following objectives: define diffusion within a school system and…

  6. Improved refractories for slagging gasifiers in IGCC power systems

    SciTech Connect

    Bennett, James P.; Kwong, Kyei-Sing; Powell, Cynthia A.; Chinn, Richard E.

    2004-01-01

    Most gasifiers are operated for refining, chemical production, and power generation. They are also considered a possible future source of H2 for future power systems under consideration. A gasifier fulfills these roles by acting as a containment vessel to react carbon-containing raw materials with oxygen and water using fluidized-bed, moving-bed, or entrained-flow systems to produce CO and H2, along with other gaseous by-products including CO2, CH4, SOx, HS, and/or NOx. The gasification process provides the opportunity to produce energy more efficiently and with less environmental impact than more conventional combustion processes. Because of these advantages, gasification is viewed as one of the key processes in the U.S. Department of Energy?s vision of an advanced power system for the 21st Century. However, issues with both the reliability and the economics of gasifier operation will have to be resolved before gasification will be widely adopted by the power industry. Central to both enhanced reliability and economics is the development of materials with longer service lives in gasifier systems that can provide extended periods of continuous, trouble-free gasifier operation. The focus of the Advanced Refractories for Gasification project at the Albany Research Center (ARC) is to develop improved refractory liner materials capable of withstanding the harsh, high-temperature environment created by the gasification reaction. Current generation refractory liners in slagging gasifiers are typically replaced every 3 to 18 months at costs ranging up to $1,000,000 or more, depending upon the size of the gasification vessel. Compounding materials and installation costs are the lost-opportunity costs for the time that the gasifier is off-line for refractory repair/exchange. The goal of this project is to develop new refractory materials or to extend the service life of refractory liner materials currently used to at least 3 years. Post-mortem analyses of refractory brick

  7. Building High-Performing and Improving Education Systems. Systems and Structures: Powers, Duties and Funding. Review

    ERIC Educational Resources Information Center

    Slater, Liz

    2013-01-01

    This Review looks at the way high-performing and improving education systems share out power and responsibility. Resources--in the form of funding, capital investment or payment of salaries and other ongoing costs--are some of the main levers used to make policy happen, but are not a substitute for well thought-through and appropriate policy…

  8. Peer review for biomedical publications: we can improve the system.

    PubMed

    Stahel, Philip F; Moore, Ernest E

    2014-01-01

    The lack of formal training programs for peer reviewers places the scientific quality of biomedical publications at risk, as the introduction of 'hidden' bias may not be easily recognized by the reader. The exponential increase in the number of manuscripts submitted for publication worldwide, estimated in the millions annually, overburdens the capability of available qualified referees. Indeed, the workload imposed on individual reviewers appears to be reaching a 'breaking point' that may no longer be sustainable. Some journals have made efforts to improve peer review via structured guidelines, courses for referees, and employing biostatisticians to ensure appropriate study design and analyses. Further strategies designed to incentivize and reward peer review work include journals providing continuing medical education (CME) credits to individual referees by defined criteria for timely and high-quality evaluations. Alternative options to supplement the current peer review process consist of 'post-publication peer review,' 'decoupled peer review,' 'collaborative peer review,' and 'portable peer review'. This article outlines the shortcomings and flaws in the current peer review system and discusses new innovative options on the horizon. PMID:25270270

  9. Improving the representation of hydrologic processes in Earth System Models

    NASA Astrophysics Data System (ADS)

    Clark, Martyn P.; Fan, Ying; Lawrence, David M.; Adam, Jennifer C.; Bolster, Diogo; Gochis, David J.; Hooper, Richard P.; Kumar, Mukesh; Leung, L. Ruby; Mackay, D. Scott; Maxwell, Reed M.; Shen, Chaopeng; Swenson, Sean C.; Zeng, Xubin

    2015-08-01

    Many of the scientific and societal challenges in understanding and preparing for global environmental change rest upon our ability to understand and predict the water cycle change at large river basin, continent, and global scales. However, current large-scale land models (as a component of Earth System Models, or ESMs) do not yet reflect the best hydrologic process understanding or utilize the large amount of hydrologic observations for model testing. This paper discusses the opportunities and key challenges to improve hydrologic process representations and benchmarking in ESM land models, suggesting that (1) land model development can benefit from recent advances in hydrology, both through incorporating key processes (e.g., groundwater-surface water interactions) and new approaches to describe multiscale spatial variability and hydrologic connectivity; (2) accelerating model advances requires comprehensive hydrologic benchmarking in order to systematically evaluate competing alternatives, understand model weaknesses, and prioritize model development needs, and (3) stronger collaboration is needed between the hydrology and ESM modeling communities, both through greater engagement of hydrologists in ESM land model development, and through rigorous evaluation of ESM hydrology performance in research watersheds or Critical Zone Observatories. Such coordinated efforts in advancing hydrology in ESMs have the potential to substantially impact energy, carbon, and nutrient cycle prediction capabilities through the fundamental role hydrologic processes play in regulating these cycles.

  10. Improved thermal storage material for portable life support systems

    NASA Technical Reports Server (NTRS)

    Kellner, J. D.

    1975-01-01

    The availability of thermal storage materials that have heat absorption capabilities substantially greater than water-ice in the same temperature range would permit significant improvements in performance of projected portable thermal storage cooling systems. A method for providing increased heat absorption by the combined use of the heat of solution of certain salts and the heat of fusion of water-ice was investigated. This work has indicated that a 30 percent solution of potassium bifluoride (KHF2) in water can absorb approximately 52 percent more heat than an equal weight of water-ice, and approximately 79 percent more heat than an equal volume of water-ice. The thermal storage material can be regenerated easily by freezing, however, a lower temperature must be used, 261 K as compared to 273 K for water-ice. This work was conducted by the United Aircraft Research Laboratories as part of a program at Hamilton Standard Division of United Aircraft Corporation under contract to NASA Ames Research Center.

  11. A novel system identification technique for improved wearable hemodynamics assessment.

    PubMed

    Wiens, Andrew D; Inan, Omer T

    2015-05-01

    Recent advances have led to renewed interest in ballistocardiography (BCG), a noninvasive measure of the small movements of the body due to cardiovascular events. A broad range of platforms have been developed and verified for BCG measurement including beds, chairs, and weighing scales: while the body is coupled to such a platform, the cardiogenic movements are measured. Wearable BCG, measured with an accelerometer affixed to the body, may enable continuous, or more regular, monitoring during the day; however, the signals from such wearable BCGs represent local or distal accelerations of skin and tissue rather than the whole body. In this paper, we propose a novel method to reconstruct the BCG measured with a weighing scale (WS BCG) from a wearable sensor via a training step to remove these local effects. Preliminary validation of this method was performed with 15 subjects: the wearable sensor was placed at three locations on the surface of the body while WS BCG measurements were recorded simultaneously. A regularized system identification approach was used to reconstruct the WS BCG from the wearable BCG. Preliminary results suggest that the relationship between local and central disturbances is highly dependent on both the individual and the location where the accelerometer is placed on the body and that these differences can be resolved via calibration to accurately measure changes in cardiac output and contractility from a wearable sensor. Such measurements could be highly effective, for example, for improved monitoring of heart failure patients at home. PMID:25561589

  12. Heat Exchange System Improvement Saves Energy and Improves Production at a Winery

    SciTech Connect

    2001-08-01

    In 2000, Fetzer Vineyards implemented a project to improve its process heating cycle at its Hopland Winery in Hopland, California. In an effort to reduce expenditures on natural gas, Fetzer reviewed their wine process heating cycle and discovered that they could reduce their natural gas purchases and improve efficiency by installing a heat exchanger.

  13. Corals form characteristic associations with symbiotic nitrogen-fixing bacteria.

    PubMed

    Lema, Kimberley A; Willis, Bette L; Bourne, David G

    2012-05-01

    The complex symbiotic relationship between corals and their dinoflagellate partner Symbiodinium is believed to be sustained through close associations with mutualistic bacterial communities, though little is known about coral associations with bacterial groups able to fix nitrogen (diazotrophs). In this study, we investigated the diversity of diazotrophic bacterial communities associated with three common coral species (Acropora millepora, Acropora muricata, and Pocillopora damicormis) from three midshelf locations of the Great Barrier Reef (GBR) by profiling the conserved subunit of the nifH gene, which encodes the dinitrogenase iron protein. Comparisons of diazotrophic community diversity among coral tissue and mucus microenvironments and the surrounding seawater revealed that corals harbor diverse nifH phylotypes that differ between tissue and mucus microhabitats. Coral mucus nifH sequences displayed high heterogeneity, and many bacterial groups overlapped with those found in seawater. Moreover, coral mucus diazotrophs were specific neither to coral species nor to reef location, reflecting the ephemeral nature of coral mucus. In contrast, the dominant diazotrophic bacteria in tissue samples differed among coral species, with differences remaining consistent at all three reefs, indicating that coral-diazotroph associations are species specific. Notably, dominant diazotrophs for all coral species were closely related to the bacterial group rhizobia, which represented 71% of the total sequences retrieved from tissue samples. The species specificity of coral-diazotroph associations further supports the coral holobiont model that bacterial groups associated with corals are conserved. Our results suggest that, as in terrestrial plants, rhizobia have developed a mutualistic relationship with corals and may contribute fixed nitrogen to Symbiodinium. PMID:22344646

  14. Symbiotic bacteria appear to mediate hyena social odors.

    PubMed

    Theis, Kevin R; Venkataraman, Arvind; Dycus, Jacquelyn A; Koonter, Keith D; Schmitt-Matzen, Emily N; Wagner, Aaron P; Holekamp, Kay E; Schmidt, Thomas M

    2013-12-01

    All animals harbor beneficial microbes. One way these microbes can benefit their animal hosts is by increasing the diversity and efficacy of communication signals available to the hosts. The fermentation hypothesis for mammalian chemical communication posits that bacteria in the scent glands of mammals generate odorous metabolites used by their hosts for communication and that variation in host chemical signals is a product of underlying variation in the bacterial communities inhabiting the scent glands. An effective test of this hypothesis would require accurate surveys of the bacterial communities in mammals' scent glands and complementary data on the odorant profiles of scent secretions--both of which have been historically lacking. Here we use next-generation sequencing to survey deeply the bacterial communities in the scent glands of wild spotted and striped hyenas. We show that these communities are dominated by fermentative bacteria and that the structures of these communities covary with the volatile fatty acid profiles of scent secretions in both hyena species. The bacterial and volatile fatty acid profiles of secretions differ between spotted and striped hyenas, and both profiles vary with sex and reproductive state among spotted hyenas within a single social group. Our results strongly support the fermentation hypothesis for chemical communication, suggesting that symbiotic bacteria underlie species-specific odors in both spotted and striped hyenas and further underlie sex and reproductive state-specific odors among spotted hyenas. We anticipate that the fermentation hypothesis for chemical communication will prove broadly applicable among scent-marking mammals as others use the technical and analytical approaches used here. PMID:24218592

  15. Does a Common Pathway Transduce Symbiotic Signals in Plant-Microbe Interactions?

    PubMed

    Genre, Andrea; Russo, Giulia

    2016-01-01

    Recent years have witnessed major advances in our knowledge of plant mutualistic symbioses such as the rhizobium-legume symbiosis (RLS) and arbuscular mycorrhizas (AM). Some of these findings caused the revision of longstanding hypotheses, but one of the most solid theories is that a conserved set of plant proteins rules the transduction of symbiotic signals from beneficial glomeromycetes and rhizobia in a so-called common symbiotic pathway (CSP). Nevertheless, the picture still misses several elements, and a few crucial points remain unclear. How does one common pathway discriminate between - at least - two symbionts? Can we exclude that microbes other than AM fungi and rhizobia also use this pathway to communicate with their host plants? We here discuss the possibility that our current view is biased by a long-lasting focus on legumes, whose ability to develop both AM and RLS is an exception among plants and a recent innovation in their evolution; investigations in non-legumes are starting to place legume symbiotic signaling in a broader perspective. Furthermore, recent studies suggest that CSP proteins act in a wider scenario of symbiotic and non-symbiotic signaling. Overall, evidence is accumulating in favor of distinct activities for CSP proteins in AM and RLS, depending on the molecular and cellular context where they act. PMID:26909085

  16. Does a Common Pathway Transduce Symbiotic Signals in Plant–Microbe Interactions?

    PubMed Central

    Genre, Andrea; Russo, Giulia

    2016-01-01

    Recent years have witnessed major advances in our knowledge of plant mutualistic symbioses such as the rhizobium-legume symbiosis (RLS) and arbuscular mycorrhizas (AM). Some of these findings caused the revision of longstanding hypotheses, but one of the most solid theories is that a conserved set of plant proteins rules the transduction of symbiotic signals from beneficial glomeromycetes and rhizobia in a so-called common symbiotic pathway (CSP). Nevertheless, the picture still misses several elements, and a few crucial points remain unclear. How does one common pathway discriminate between – at least – two symbionts? Can we exclude that microbes other than AM fungi and rhizobia also use this pathway to communicate with their host plants? We here discuss the possibility that our current view is biased by a long-lasting focus on legumes, whose ability to develop both AM and RLS is an exception among plants and a recent innovation in their evolution; investigations in non-legumes are starting to place legume symbiotic signaling in a broader perspective. Furthermore, recent studies suggest that CSP proteins act in a wider scenario of symbiotic and non-symbiotic signaling. Overall, evidence is accumulating in favor of distinct activities for CSP proteins in AM and RLS, depending on the molecular and cellular context where they act. PMID:26909085

  17. Comparative gene expression in the symbiotic and aposymbiotic Aiptasia pulchella by expressed sequence tag analysis.

    PubMed

    Kuo, Jimmy; Chen, Ming-Chyuan; Lin, Chorng-Horng; Fang, Lee-Shing

    2004-05-21

    Intracellular symbiotic relationships are prevalent between cnidarians, such as corals and sea anemones, and the photosynthetic dinoflagellate symbionts. However, there is little understanding about how the genes express when the symbiotic relationship is set up. To characterize genes involved in this association, the endosymbiosis between sea anemone, Aiptasia pulchella, and dinoflagellate zooxanthellae, Symbiodinium spp., was employed as a model. Two complementary DNA (cDNA) libraries were constructed from RNA isolated from symbiotic and aposymbiotic A. pulchella. Using single-pass sequencing of cDNA clones, a total of 870 expressed sequence tags (ESTs) clones were generated from the two libraries: 474 from symbiotic animal and 396 from aposymbiotic animal. The initial ESTs consisted of 143 clusters and 231 singletons. A BLASTX search revealed that 147 unique genes had similarities with protein sequences available from databases; 120 of these clones were categorized according to their putative function. However, many ESTs could not assign functionally. The putative roles of some of the identified genes relative to endosymbiosis were discussed. This is the first report of the use of EST analysis to examine the gene expression in symbiotic and aposymbiotic states of the cnidarians. The systematic analysis of EST from this study provides a useful database for future investigations of the molecular mechanisms involved in algal-cnidarian symbiosis. PMID:15110770

  18. Viruses of symbiotic Chlorella-like algae isolated from Paramecium bursaria and Hydra viridis

    PubMed Central

    Van Etten, James L.; Meints, Russel H.; Kuczmarski, Daniel; Burbank, Dwight E.; Lee, Kit

    1982-01-01

    We previously reported that isolation of symbiotic Chlorella-like algae from the Florida strain of Hydra viridis induced replication of a virus (designated HVCV-1) in the algae. We now report that isolation of symbiotic Chlorella-like algae from four other sources of green hydra and one source of the protozoan Paramecium bursaria also induced virus synthesis. Algae from one of these hydra contained a virus identical to HVCV-1 (based on its rate of sedimentation, buoyant density, reaction to HVCV-1 antiserum, and DNA restriction fragments) whereas algae from the other three hydra contained another similar, but distinct, virus (designated HVCV-2). The virus from the paramecium algae (designated PBCV-1) was distinct from both HVCV-1 and HVCV-2. The symbiotic algae in the hydra could also be distinguished ultrastructurally. Chloroplasts of both algae that produced HVCV-1 lacked a pyrenoid whereas chloroplasts of the other three symbiotic algae contained pyrenoids. Since all symbiotic eukaryotic algae we have examined have had virus, a potential viral role in symbiosis is suggested. Images PMID:16593198

  19. Techniques for Improving the Performance of Future EVA Maneuvering Systems

    NASA Technical Reports Server (NTRS)

    Williams, Trevor W.

    1995-01-01

    The Simplified Aid for EVA Rescue (SAFER) is a small propulsive backpack that was developed as an in-house effort at Johnson Space Center; it is a lightweight system which attaches to the underside of the Primary Life Support Subsystem (PLSS) backpack of the Extravehicular Mobility Unit (EMU). SAFER provides full six-axis control, as well as Automatic Attitude Hold (AAH), by means of a set of cold-gas nitrogen thrusters and a rate sensor-based control system. For compactness, a single hand controller is used, together with mode switching, to command all six axes. SAFER was successfully test-flown on the STS-64 mission in September 1994 as a Development Test Objective (DTO); development of an operational version is now proceeding. This version will be available for EVA self-rescue on the International Space Station and Mir, starting with the STS-86/Mir-7 mission in September 1997. The DTO SAFER was heavily instrumented, and produced in-flight data that was stored in a 12 MB computer memory on-board. This has allowed post-flight analysis to yield good estimates for the actual mass properties (moments and products of inertia and center of mass location) encountered on-orbit. By contrast, Manned Maneuvering Unit (MMU) post-flight results were generated mainly from analysis of video images, and so were not very accurate. The main goal of the research reported here was to use the detailed SAFER on-orbit mass properties data to optimize the design of future EVA maneuvering systems, with the aim being to improve flying qualities and/or reduce propellant consumption. The Automation, Robotics and Simulation Division Virtual Reality (VR) Laboratory proved to be a valuable research tool for such studies. A second objective of the grant was to generate an accurate dynamics model in support of the reflight of the DTO SAFER on STS-76/Mir-3. One complicating factor was the fact that a hand controller stowage box was added to the underside of SAFER on this flight; the position of

  20. Novel technologies to improve the performance of biomass pyrolsis systems

    NASA Astrophysics Data System (ADS)

    Liaw, Shi-Shen

    Biomass pyrolysis is a thermochemical conversion process to convert lignocellosic materials into bio-oil, gas, and char. The bio-oil can be further refined to produce transportation fuels, high-value chemicals and heat. Although fast pyrolysis is a very promising technology for high bio-oil production yield, the reactors used have several technological problems that limit their future techno-economic viability. Current fast pyrolysis reactors use large quantities of carrier gas that reduce their thermal efficiency. The use of sand to accelerate heating rates results in serious attrition problems responsible for sand contamination of the bio-char produced. Most of the fast pyrolysis reactors currently used need to process very small particles which consume large quantities of energy in grinding. The bio-oil produced is also highly acidic and corrosive mainly due to the presence of acetic acid. The lack of a viable technology to use the acetic acid contained in these oils is a major challenge for the development of viable bio-oil refineries. The objective of this dissertation is to evaluate several technologies to improve the techno-economic viability of biomass pyrolysis systems. The main hypotheses of this dissertation are: (1) high yields of bio-oils could also be obtained by using auger pyrolysis reactors using very low volumes of carried gas and no sand as a heat carrier if the system is fed with very small particles (2) The grinding energy can be reduced if the biomass is torrefied. There are torrefaction conditions that will not affect the overall yield of pyrolysis products (3) Acetic acid produced during pyrolysis can be removed with the use of a fractional condensation system (4) The acids produced during the torrefaction and pyrolysis with the use of the fractional condensation system can be anaerobically digested to produce methane. In this dissertation, it was proved through Py-GC/MS studies that yield of most of the pyrolytic products can be explained